WO2021095845A1 - Ceramic substrate, composite substrate, circuit board, ceramic substrate production method, composite substrate production method, circuit board production method, and method for producing multiple circuit boards - Google Patents

Ceramic substrate, composite substrate, circuit board, ceramic substrate production method, composite substrate production method, circuit board production method, and method for producing multiple circuit boards Download PDF

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WO2021095845A1
WO2021095845A1 PCT/JP2020/042422 JP2020042422W WO2021095845A1 WO 2021095845 A1 WO2021095845 A1 WO 2021095845A1 JP 2020042422 W JP2020042422 W JP 2020042422W WO 2021095845 A1 WO2021095845 A1 WO 2021095845A1
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ceramic substrate
manufacturing
metal layer
cutting
green sheet
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PCT/JP2020/042422
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French (fr)
Japanese (ja)
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晃正 湯浅
優太 津川
善幸 江嶋
貴裕 中村
小橋　聖治
西村　浩二
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デンカ株式会社
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Priority to JP2021556171A priority Critical patent/JPWO2021095845A1/ja
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    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
    • C04B35/58—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides
    • C04B35/581—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides based on aluminium nitride
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/36—Removing material
    • B23K26/362—Laser etching
    • B23K26/364—Laser etching for making a groove or trench, e.g. for scribing a break initiation groove
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/36—Removing material
    • B23K26/38—Removing material by boring or cutting
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B18/00—Layered products essentially comprising ceramics, e.g. refractory products
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B37/00—Joining burned ceramic articles with other burned ceramic articles or other articles by heating
    • C04B37/02—Joining burned ceramic articles with other burned ceramic articles or other articles by heating with metallic articles
    • C04B37/023—Joining burned ceramic articles with other burned ceramic articles or other articles by heating with metallic articles characterised by the interlayer used
    • C04B37/026—Joining burned ceramic articles with other burned ceramic articles or other articles by heating with metallic articles characterised by the interlayer used consisting of metals or metal salts
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/02—Details
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/02—Details
    • H05K1/03—Use of materials for the substrate
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3205—Alkaline earth oxides or oxide forming salts thereof, e.g. beryllium oxide
    • C04B2235/3206—Magnesium oxides or oxide-forming salts thereof
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3224—Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide
    • C04B2235/3225—Yttrium oxide or oxide-forming salts thereof
    • C—CHEMISTRY; METALLURGY
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    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/60—Aspects relating to the preparation, properties or mechanical treatment of green bodies or pre-forms
    • C04B2235/602—Making the green bodies or pre-forms by moulding
    • C04B2235/6025—Tape casting, e.g. with a doctor blade
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
    • C04B2235/656—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes characterised by specific heating conditions during heat treatment
    • C04B2235/6562—Heating rate
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
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    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
    • C04B2235/656—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes characterised by specific heating conditions during heat treatment
    • C04B2235/6565—Cooling rate
    • C—CHEMISTRY; METALLURGY
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    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
    • C04B2235/66—Specific sintering techniques, e.g. centrifugal sintering
    • C04B2235/661—Multi-step sintering
    • C—CHEMISTRY; METALLURGY
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    • C04B2237/00—Aspects relating to ceramic laminates or to joining of ceramic articles with other articles by heating
    • C04B2237/30—Composition of layers of ceramic laminates or of ceramic or metallic articles to be joined by heating, e.g. Si substrates
    • C04B2237/32—Ceramic
    • C04B2237/36—Non-oxidic
    • C04B2237/366—Aluminium nitride
    • C—CHEMISTRY; METALLURGY
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    • C04B2237/00—Aspects relating to ceramic laminates or to joining of ceramic articles with other articles by heating
    • C04B2237/30—Composition of layers of ceramic laminates or of ceramic or metallic articles to be joined by heating, e.g. Si substrates
    • C04B2237/32—Ceramic
    • C04B2237/36—Non-oxidic
    • C04B2237/368—Silicon nitride

Definitions

  • the present invention relates to a ceramic substrate, a composite substrate, a circuit board, a method for manufacturing a ceramic substrate, a method for manufacturing a composite substrate, a method for manufacturing a circuit board, and a method for manufacturing a plurality of circuit boards.
  • Patent Document 1 it is known that metal layers are fixed on both sides of a ceramic substrate to form a composite substrate, and a circuit pattern is formed on one metal layer of the composite substrate to form a circuit board. ..
  • This circuit board is used for, for example, a power module because it is excellent in terms of high thermal conductivity and high insulation.
  • Each such a ceramic substrate includes a metal layer forming step of fixing a metal layer (for example, a copper plate) on both sides thereof, a circuit pattern forming step of forming a circuit pattern on at least one of the metal layers, and a scribing line forming step. It is processed into a circuit board through a process. In each of these steps, various thermal histories are added in a state where the ceramic substrate and the copper plate, which have different coefficients of thermal expansion, are joined to each other. Therefore, a certain amount of heat is added to the inside of the finally obtained circuit board. It is inevitable that strain and thermal stress will remain.
  • a metal layer for example, a copper plate
  • An object of the present invention is to provide a ceramic substrate capable of producing a circuit board having excellent flatness in which residual thermal strain and residual thermal stress are remarkably reduced.
  • the ceramic substrate of the first aspect of the present invention is a ceramic substrate having a rectangular shape in a plan view, and the value obtained by dividing the maximum height difference in the plate thickness direction of the ceramic substrate by the diagonal length of the ceramic substrate is It is 1 ⁇ m / mm or less, and a plurality of cracks are formed at the end thereof from one end to the other end in the plate thickness direction in the in-plane direction from the main surface end portion of the ceramic substrate.
  • the ceramic substrate of the second aspect of the present invention is the ceramic substrate, and the plurality of cracks are formed over the entire circumference of the end portion.
  • the ceramic substrate of the third aspect of the present invention is the ceramic substrate and includes silicon nitride or aluminum nitride.
  • the composite substrate of one aspect of the present invention includes the ceramic substrate, a first metal layer fixed to the front surface side of the ceramic substrate, and a second metal layer fixed to the back surface side of the ceramic substrate. Be prepared.
  • the circuit board of one aspect of the present invention includes the ceramic substrate, a circuit pattern formed on the front surface side of the ceramic substrate, and a metal layer fixed to the back surface side of the ceramic substrate.
  • the method for producing a ceramic substrate according to the first aspect of the present invention is the method for producing a ceramic substrate, which is a step of cutting a strip-shaped green sheet containing a ceramic powder to obtain a single-wafer green sheet, and firing.
  • the single-wafer green sheet is placed in the chamber, the firing chamber is heated until the temperature in the firing chamber reaches at least 1600 ° C., and then the firing chamber is cooled, and the single-wafer green sheet is sintered to obtain the above. It includes a sintering step of obtaining a ceramic substrate, and a cutting step of the ceramic substrate that cuts a portion of the ceramic substrate cooled on the entire peripheral edge side after the sintering step.
  • the method for manufacturing a ceramic substrate according to the second aspect of the present invention is the method for manufacturing the ceramic substrate, and in the step of cutting the ceramic substrate, the laser light source is applied to the entire circumference of the portion on the entire peripheral edge side of the ceramic substrate in the circumferential direction.
  • a crack is formed at the end portion formed by cutting the ceramic substrate by intermittently irradiating the ceramic substrate with a laser beam while scanning the ceramic substrate.
  • the method for manufacturing the ceramic substrate according to the third aspect of the present invention is the method for manufacturing the ceramic substrate.
  • the temperature in the firing chamber becomes 650 ° C. or lower when the firing chamber is cooled. In some cases, the temperature in the firing chamber is rapidly cooled.
  • the method for producing a ceramic substrate according to the fourth aspect of the present invention is the method for producing a ceramic substrate, and the ceramic powder includes silicon nitride powder or aluminum nitride powder.
  • the method for manufacturing a composite substrate according to one aspect of the present invention includes a method for manufacturing the ceramic substrate, a fixing step of fixing the first metal layer on the front surface side of the ceramic substrate, and fixing the second metal layer on the back surface side. including.
  • the method for manufacturing a circuit board according to one aspect of the present invention includes a method for manufacturing the composite substrate and a pattern forming step for forming at least one circuit pattern on either the first metal layer or the second metal layer. ,including.
  • the method for manufacturing a plurality of circuit boards according to one aspect of the present invention is a pattern forming step of forming a plurality of circuit patterns on either the method for manufacturing the composite substrate and the first metal layer and the second metal layer. And a division step of dividing the composite substrate on which the plurality of circuit patterns are formed into a plurality of circuit boards each having one of the circuit patterns.
  • Warpage and internal stress of the bonded substrate and circuit board to which the metal layer is bonded can be effectively reduced.
  • the ceramic substrate of the present invention and the composite substrate including the ceramic substrate of the present invention it is possible to produce a circuit board having excellent flatness in which residual thermal strain and residual thermal stress are remarkably reduced.
  • the circuit board of the present invention has high reliability with excellent flatness in which residual thermal strain and residual thermal stress are remarkably reduced.
  • a highly reliable circuit board having excellent flatness with remarkably reduced residual thermal strain and residual thermal stress can be obtained.
  • FIG. 2C is a schematic view of FIG.
  • 2C viewed from the front side. It is a figure for demonstrating from the deposition process included in the green sheet forming process of this embodiment to the sintering process in the manufacturing method of a plurality of mounting substrates of this embodiment. It is a graph which shows the profile of the firing temperature in the sintering process (including the condition examined by the test). It is a graph which shows the relationship between the quenching start temperature in a firing process (including the condition examined by a test), and the amount of warpage. It is a top view of the ceramic substrate of the 1st example of this embodiment, and is the height distribution map in the state which the profile of the degree of height (the degree of dent) in the thickness direction is attached.
  • FIG. 3 is a cross-sectional view of the ceramic substrate of the first example of FIG. 3D, which is a cross-sectional view cut along a BB cutting line. It is a top view of the ceramic substrate of the 2nd example of this embodiment, and is the high-low distribution map in the state which the profile of the high-low degree degree (the degree of dent) in the plate thickness direction is attached.
  • FIG. 3 is a cross-sectional view of the ceramic substrate of the second example of FIG. 3G, which is a cross-sectional view cut along the AA cutting line.
  • FIG. 3 is a cross-sectional view of the ceramic substrate of the second example of FIG. 3G, which is a cross-sectional view cut along a BB cutting line. It is a top view of the ceramic substrate of the 3rd example of this embodiment, and is the high-low distribution map in a state with the profile of the high-low degree degree (the degree of dent) in the plate thickness direction. It is sectional drawing of the ceramic substrate of the 3rd example of FIG. 3J, and is the sectional view cut by the AA cutting line. It is sectional drawing of the ceramic substrate of the 3rd example of FIG. 3J, and is the sectional view cut by the BB cutting line.
  • FIG. 3 is a cross-sectional view of the ceramic substrate of the fourth example of FIG. 3M, which is a cross-sectional view cut along the AA cutting line.
  • FIG. 3 is a cross-sectional view of the ceramic substrate of the fourth example of FIG. 3M, which is a cross-sectional view cut along a BB cutting line.
  • FIG. 3 is a graph showing a displacement amount distribution measured along a laser three-dimensional shape measuring machine along a CC straight line in FIGS. 3S to 3V. It is the schematic for demonstrating the outer peripheral part cutting process included in the manufacturing method of the plurality of mounting substrates of this embodiment. It is a graph which shows the relationship between the cutting width of the outer peripheral part and the amount of warpage in the outer peripheral part cutting process. It is a figure for demonstrating the scrib line forming process included in the manufacturing method of the plurality of mounting substrates of this embodiment. It is a figure for demonstrating the metal layer formation process included in the manufacturing method of the plurality of mounting substrates of this embodiment.
  • FIG. 6A is a cross-sectional view of the ceramic substrate of FIG.
  • 6A which is a cross-sectional view cut along a 6B-6B cutting line. It is a partial perspective view of the ceramic substrate of this embodiment. It is a figure for demonstrating the resist printing process included in the manufacturing method of the plurality of mounting substrates of this embodiment. It is a figure for demonstrating the etching process included in the manufacturing method of the plurality of mounting substrates of this embodiment. It is a figure for demonstrating the division process included in the manufacturing method of the plurality of mounting substrates of this embodiment. It is a figure for demonstrating the metal layer formation process of the 1st modification. It is a top view of the ceramic substrate of the 2nd modification, and is the height distribution figure in the state which the profile of the degree of height (the degree of dent) in the thickness direction is attached.
  • 11A is a cross-sectional view of the ceramic substrate, which is a vertical cross-sectional view cut along the X 0- X 0 cutting line, a vertical cross-sectional view cut along the X 1- X 1 cutting line, and cut along the X 2- X 2 cutting line. It is the figure which arranged the vertical sectional views along the X direction, respectively.
  • 11A is a cross-sectional view of the ceramic substrate, which is a cross-sectional view cut along a Y 0- Y 0 cutting line, a cross-sectional view cut along a Y 1- Y 1 cutting line, and a cross section cut along a Y 2- Y 2 cutting line. It is the figure which arranged the cross-sectional view along the Y direction respectively.
  • the present embodiment will be described with reference to the drawings.
  • the ceramic substrate 40 of the present embodiment see FIGS. 3A, 3D, 3G, 3J, 3M, 3P, 3S, etc.
  • the motherboard 60 an example of a composite substrate, see 6A and 6B.
  • the assembly board 60B another example of the composite board, see FIGS. 8 and 9) and the circuit board 60C (see FIG. 9) will be described.
  • a method of manufacturing a plurality of mounting substrates (not shown) of the present embodiment will be described in the order of each process shown in FIG. 1 with reference to FIG. 1 and the like. Next, the effect of this embodiment will be described.
  • FIGS. 10 and 11A to 11C Similar components are designated by the same reference numerals, and the description thereof will be omitted as appropriate.
  • Ceramic substrate 40 of the present embodiment will be described with reference to FIGS. 3D to 3W and FIGS. 6B to 6C.
  • the ceramic substrate 40 of this embodiment has the following basic features.
  • the ceramic substrate 40 has a rectangular shape in a plan view, and the value obtained by dividing the maximum height difference of the ceramic substrate 40 in the plate thickness direction by the diagonal length of the ceramic substrate 40 is 1 ⁇ m / mm or less, and the end thereof.
  • a plurality of crack MCs are formed in the portion from one end to the other end in the plate thickness direction in the in-plane direction from the main surface end portion of the ceramic substrate 40. That is, the ceramic substrate 40 of the present embodiment is substantially flat or completely flat, and a plurality of crack MCs are formed at the ends thereof from one end to the other end in the plate thickness direction of the ceramic substrate 40. ing.
  • the maximum height difference in this embodiment will be described in the description of the sixth example. Further, "the value obtained by dividing the diagonal length of the ceramic substrate 40 by the maximum height difference in the plate thickness direction of the ceramic substrate 40" is defined as the "maximum height value".
  • the ceramic substrate 40 of the present embodiment may have some irregularities in the plate thickness direction as long as it satisfies the regulation of the maximum height difference, which is one of the above basic features. That is, at least one convex portion that becomes convex toward one side or the other side in the plate thickness direction may be formed. Then, as an embodiment in which such a convex portion is formed, the following can be mentioned.
  • the ceramic substrate 40 of one aspect of the ceramic substrate 40 of the present embodiment is formed with at least one convex portion that is convex toward one side or the other side in the plate thickness direction (the ceramic substrate 40). 3D, 3G, 3J, 3M, 3P and 3S).
  • At least one convex portion is a plurality of convex portions, and the plurality of convex portions are each a ceramic substrate. It is formed in two regions defined by one of the pair of diagonal lines in 40 (see FIGS. 3D, 3G, 3J and 3M). Further, for example, in the ceramic substrate 40 of one aspect of the ceramic substrate 40 of the present embodiment, at least one convex portion is a plurality of convex portions, and the plurality of convex portions are each a ceramic substrate. It is formed in four regions defined by a pair of diagonal lines in 40 (see FIG. 3M).
  • At least one convex portion is a plurality of convex portions, and a part of the plurality of convex portions is.
  • the ceramic substrate 40 is formed so as to be convex toward one side in the plate thickness direction.
  • the remaining part of the plurality of convex portions is formed so as to be convex toward the other side in the plate thickness direction (see FIGS. 3D, 3M, and 3P).
  • the surface 40A1 of the ceramic substrate 40 is a substantially flat surface although it has some irregularities. Not limited to these examples, the surface 40A1 of the ceramic substrate 40 may be a completely flat surface having no convex portion.
  • the first to sixth examples described below are merely examples of the ceramic substrate 40 of the present embodiment, and any ceramic substrate having the above basic characteristics can be used as the ceramic substrate 40 of the present embodiment. included.
  • FIG. 3D is a plan view of the ceramic substrate 40 of the first example of the present embodiment, and is a height distribution diagram in a state where a profile of the degree of height (depression) in the thickness direction (Z direction) is attached.
  • FIG. 3E is a cross-sectional view of the ceramic substrate 40 of the first example, and is a cross-sectional view of the ceramic substrate 40 of the first example cut along the AA cutting line of FIG. 3D.
  • FIG. 3D is a plan view of the ceramic substrate 40 of the first example of the present embodiment, and is a height distribution diagram in a state where a profile of the degree of height (depression) in the thickness direction (Z direction) is attached.
  • FIG. 3E is a cross-sectional view of the ceramic substrate 40 of the first example, and is a cross-sectional view of the ceramic substrate 40 of the first example cut along the AA cutting line of FIG. 3D.
  • 3F is a cross-sectional view of the ceramic substrate 40 of the first example, and is a cross-sectional view of the ceramic substrate 40 of the first example cut along the BB cutting line of FIG. 3D.
  • the ceramic substrate 40 of the first example has the following features.
  • the end portion of the ceramic substrate 40 is in-plane from the main surface end portion 40A3 of the ceramic substrate 40, and from one end (surface 40A1) to the other end in the plate thickness direction (Z direction).
  • a plurality of microcracks MC are formed over (back surface 40A2) (see FIGS. 6B and 6C).
  • the plurality of microcracks MC are formed over the entire circumference of the end portion, that is, the entire outer peripheral surface (hereinafter, referred to as the first feature).
  • the plurality of microcracks MC are arranged at intervals p1 defined in the circumferential direction of the end portion.
  • the defined interval p1 is, for example, 90 ⁇ m or more and 110 ⁇ m or less.
  • the length L11 of the microcrack MC on the main surface side (surface 40A1 side) is, for example, 15 ⁇ m or more and 25 ⁇ m or less.
  • one of the plate thickness directions is located at a position deviated from the intersection O formed by the pair of diagonal lines (a pair of broken lines in FIG. 3D) in a plan view.
  • At least one convex portion is formed so as to be convex toward the side or the other side, and the maximum height value is 1 ⁇ m / mm or less (1 ⁇ m / mm or less).
  • the second feature is referred to as the second feature.
  • the ceramic substrate 40 of the first example and the ceramic substrates 40 of the second to fifth examples described later have a length of 206 mm and a width of 146 mm, so that the diagonal length thereof is about 252.5 mm.
  • the convex amounts of the convex portions CX1 and CX2 are defined as ⁇ Z 1 and ⁇ Z 2 , respectively.
  • the convex amounts ⁇ Z 1 and ⁇ Z 2 are 252 ⁇ m or less, respectively, as an example. That is, in the case of the first example, the maximum height difference is 252 ⁇ m or less. From the above, the maximum height value of the ceramic substrate 40 of the first example is 1 ⁇ m / mm or less.
  • the plurality of convex portions are each of the ceramic substrate 40. It is formed in two regions divided by one diagonal line (both diagonal lines in the first example) of the pair of diagonal lines in (hereinafter referred to as a third feature).
  • the ceramic substrate 40 of the first example is a part (convex) of a plurality of convex portions (convex portions CX1 and CX2 in the first example) on the premise that the maximum height value is 1 ⁇ m / mm or less.
  • One of the convex portions CX1 and CX2) is formed so as to be convex toward one side in the plate thickness direction (Z direction), and the remaining part (the other of the convex portions CX1 and CX2) is formed. It is formed so as to be convex toward the other side in the plate thickness direction (hereinafter, referred to as a fourth feature).
  • FIG. 3G is a plan view of the ceramic substrate 40 of the second example of the present embodiment, and is a height distribution diagram in a state where a profile of the degree of height (depression) in the thickness direction (Z direction) is attached.
  • FIG. 3H is a cross-sectional view of the ceramic substrate 40 of the second example, and is a cross-sectional view of the ceramic substrate 40 of the second example cut along the AA cutting line of FIG. 3G.
  • FIG. 3G is a plan view of the ceramic substrate 40 of the second example of the present embodiment, and is a height distribution diagram in a state where a profile of the degree of height (depression) in the thickness direction (Z direction) is attached.
  • FIG. 3H is a cross-sectional view of the ceramic substrate 40 of the second example, and is a cross-sectional view of the ceramic substrate 40 of the second example cut along the AA cutting line of FIG. 3G.
  • 3I is a cross-sectional view of the ceramic substrate 40 of the second example, which is a cross-sectional view of the ceramic substrate 40 of the second example cut along the BB cutting line of FIG. 3G.
  • the ceramic substrate 40 of the second example is the case of the first example (FIG. 3D) in that the convex portions CX1 and CX2 are convex on one side (surface 40A1 side) in the plate thickness direction (Z direction), respectively. See) is different.
  • the ceramic substrate 40 of the second example has the first to third features of the case of the first example.
  • FIG. 3J is a plan view of the ceramic substrate 40 of the third example of the present embodiment, and is a height distribution diagram in a state where a profile of the degree of height (depression) in the thickness direction (Z direction) is attached.
  • FIG. 3K is a cross-sectional view of the ceramic substrate 40 of the third example, and is a cross-sectional view of the ceramic substrate 40 of the third example cut along the AA cutting line of FIG. 3J.
  • FIG. 3K is a cross-sectional view of the ceramic substrate 40 of the third example, and is a cross-sectional view of the ceramic substrate 40 of the third example cut along the AA cutting line of FIG. 3J.
  • 3L is a cross-sectional view of the ceramic substrate 40 of the third example, and is a cross-sectional view of the ceramic substrate 40 of the third example cut along the BB cutting line of FIG. 3J.
  • the ceramic substrate 40 of the third example is the case of the first example (FIG. 3D) in that the convex portions CX1 and CX2 are convex on the other side (back surface 40A2 side) in the plate thickness direction (Z direction), respectively. (See) and the case of the second example (see FIG. 3G). Further, the ceramic substrate 40 of the third example has the first to third features of the case of the first example.
  • FIG. 3M is a plan view of the ceramic substrate 40 of the fourth example of the present embodiment, and is a height distribution diagram in a state where a profile of the degree of height (depression) in the thickness direction (Z direction) is attached.
  • FIG. 3N is a cross-sectional view of the ceramic substrate 40 of the fourth example, and is a cross-sectional view of the ceramic substrate 40 of the fourth example cut along the AA cutting line of FIG. 3M.
  • 3N is a cross-sectional view of the ceramic substrate 40 of the fourth example, which is a cross-sectional view of the ceramic substrate 40 of the fourth example cut along the BB cutting line of FIG. 3M.
  • a plurality of convex portions (convex portions CX1, CX2, CX3, CX4) are each paired in the ceramic substrate 40. It is formed in four regions divided by the diagonal line of (hereinafter referred to as a fifth feature).
  • the convex portions ⁇ Z 3 and ⁇ Z 4 of the convex portions CX3 and CX4 are, for example, 252 ⁇ m or less.
  • the ceramic substrate 40 of the third example has the first to fourth features of the case of the first example.
  • FIG. 3P is a plan view of the ceramic substrate 40 of the fifth example of the present embodiment, and is a height distribution diagram in a state where a profile of the degree of height (depression) in the thickness direction (Z direction) is attached.
  • FIG. 3Q is a cross-sectional view of the ceramic substrate 40 of the fifth example, and is a cross-sectional view of the ceramic substrate 40 of the fifth example cut along the AA cutting line of FIG. 3P.
  • 3R is a cross-sectional view of the ceramic substrate 40 of the fifth example, and is a cross-sectional view of the ceramic substrate 40 of the fifth example cut along the BB cutting line of FIG. 3P.
  • the convex portions CX1 and CX2 are formed in one of the four diagonally partitioned regions of the ceramic substrate 40, respectively.
  • the ceramic substrate 40 of the fifth example differs from the case of the first example (see FIG. 3D) in this respect. Further, the ceramic substrate 40 of the fifth example has the first and second features of the case of the first example.
  • FIGS. 3S to 3V are plan views of the ceramic substrate 40 of the sixth example of the present embodiment, respectively, and are provided with profiles of high and low degrees (depressions) in the plate thickness direction (Z direction). It is a high-low distribution map of the state. 3S to 3V have different measurement spans when measuring the amount of warpage, which will be described later (70 ⁇ m, 100 ⁇ m, 200 ⁇ m, and 300 ⁇ m, respectively).
  • FIG. 3W is a graph showing the displacement amount distribution measured along the laser three-dimensional shape measuring machine along the CC straight line in FIGS. 3S to 3V.
  • the amount of warpage of the ceramic substrate 40 was measured as follows. That is, a laser three-dimensional shape measuring machine (manufactured by Keyence Co., Ltd .: LK-GD500) irradiates the ceramic substrate 40 with laser light, receives the diffusely reflected light from the ceramic substrate 40, calculates the displacement amount, and calculates the amount of displacement of the ceramic.
  • the amount of warpage of the main surface of the substrate 40 was measured. In this case, the measurement pitch was 1 mm ⁇ 1 mm.
  • the "maximum height difference" in the present embodiment is calculated by calculating the reference front surface 40A1 (or back surface 40A2) from the displacement measured by the laser three-dimensional shape measuring machine, and calculating the displacement amount from the reference surface. The maximum amount of displacement when
  • the ceramic substrates 40 of Examples 1 to 6 are examples of the ceramic substrate 40 of the present embodiment, and the ceramic substrate 40 of the present embodiment includes the following. Examples such as are also included.
  • the convex portions CX1 and CX2 are located in the longitudinal direction (Y) with the intersection O of the four diagonal regions of the ceramic substrate 40 interposed therebetween. It is formed in two regions divided on both sides of the direction).
  • the convex portions CX1 and CX2 may be formed in two regions partitioned on both sides in the lateral direction (X direction) with the intersection O in between.
  • the convex portions CX2 and CX3 are convex toward the back surface 40A2 in the plate thickness direction (Z direction) of the ceramic substrate 40 (FIG. 3M). 3N, see FIG. 3O).
  • one or both of the convex portions CX2 and CX3 may be convex toward the surface 40A1.
  • a ceramic substrate (not shown) in which the convex portion CX2 (see FIG. 3P) of the ceramic substrate 40 of the fifth example is combined with the ceramic substrate 40 of the first example (see FIG. 3D) may be used.
  • the ceramic substrate 40 see FIG.
  • the ceramic substrate 40 (see FIG. 3P) of the fifth example may be a ceramic substrate (not shown) without any one of the convex portions CX1 and CX2.
  • the motherboard 60 of this embodiment includes a first metal layer 50A fixed to the front surface 40A1 side of the ceramic substrate 40, and a second metal layer 50B fixed to the back surface 40A2 side of the ceramic substrate 40.
  • the ceramic substrate 40A with SL which will be described later, is used instead of the ceramic substrate 40.
  • the ceramic substrate 40A with SL is a substrate on which a plurality of scribe lines SL are formed as an example on the ceramic substrate 40, as will be described later. The above is the description of the motherboard 60 of this embodiment.
  • the circuit board 60C of this embodiment includes a ceramic substrate 40, a circuit pattern CP formed on the front surface 40A1 side of the ceramic substrate 40, and a metal layer (second metal layer) fixed to the back surface 40A2 side of the ceramic substrate 40. 50B) and.
  • the above is the description of the circuit board 60C of this embodiment.
  • the manufacturing method S100 of the plurality of mounting substrates of the present embodiment (hereinafter, referred to as the manufacturing method S100 of the present embodiment) will be described with reference to FIG. 1 and the like.
  • the manufacturing method S100 of the present embodiment is referred to as a green sheet forming step S1, a sintering step S2, an outer peripheral partial cutting step S3, and a scribing line forming step S4 (hereinafter referred to as SL forming step S4).
  • a metal layer forming step S5 a resist printing step S6, an etching step S7, a surface treatment step S8, a dividing step S9, and a mounting step S10.
  • the manufacturing method S100 of the present embodiment is performed in the order described in each of these steps.
  • each step of the manufacturing method S100 of the present embodiment includes the following description of each invention.
  • the method for manufacturing the ceramic substrate 40 of the present embodiment includes a step of cutting the band-shaped green sheet 20 for obtaining the single-wafer green sheet 30 by cutting the band-shaped green sheet 20 containing the ceramic powder, and arranging the single-leaf green sheet 30 in the firing chamber. Then, after heating the firing chamber until the temperature in the firing chamber reaches at least 1600 ° C. or higher, the firing chamber is cooled, and the single-wafer green sheet 30 is sintered to obtain a ceramic substrate 40.
  • a step of cutting the ceramic substrate 40 which cuts a portion on the entire peripheral edge side of the cooled ceramic substrate 40 after the sintering step, is included (see FIGS. 1 and 4A). Further, in the method for manufacturing the ceramic substrate 40 of the present embodiment, in the sintering step, when the temperature in the firing chamber becomes 650 ° C. or lower when the firing chamber is cooled, the temperature in the firing chamber is rapidly cooled. (See FIGS. 1, 2B, 2C, 3B, etc.).
  • the manufacturing method of the motherboard 60 of the present embodiment is the above-mentioned manufacturing method of the ceramic substrate and the fixing of fixing the first metal layer 50A on the front surface 40A1 side of the ceramic substrate 40 and fixing the second metal layer 50B on the back surface 40A2 side. Includes steps (see FIG. 6A).
  • the method for manufacturing the circuit board 60C of the present embodiment is one of the above-mentioned manufacturing method of the motherboard 60 and either the first metal layer 50A or the second metal layer 50B (in the case of the present embodiment, the first metal layer 50A is an example.
  • the method for manufacturing the plurality of circuit boards 60C of the present embodiment is one of the above-mentioned method for manufacturing the motherboard 60 and either the first metal layer 50A or the second metal layer 50B (in the case of the present embodiment, the first metal is an example.
  • the step of combining the green sheet forming step S1 and the sintering step S2 in the present embodiment in the order described corresponds to the method for manufacturing the ceramic substrate 40.
  • the method for manufacturing the ceramic substrate 40 of the present embodiment will be described with reference to FIGS. 2A to 2D, FIGS. 3A to 3R, and FIGS. 4A and 4B.
  • the ceramic substrate 40 is used, for example, as a circuit board or a mounting substrate for a power module mounted on an electric vehicle, a railroad vehicle, or other industrial equipment.
  • the ceramic substrate 40 is obtained by sintering a single-wafer green sheet 30 (see FIG. 2C) described later in a laminated state (see FIG. 3A).
  • the single-wafer green sheet 30 is obtained by cutting the strip-shaped green sheet 20 (see FIGS. 2B and 2C). That is, the ceramic substrate 40 and the single-wafer green sheet 30 have a relationship between a finished product and an intermediate product (a product manufactured in a process before becoming a finished product), or a first intermediate product and a second intermediate product (second intermediate product).
  • the single-wafer green sheet 30 of the present embodiment is manufactured by the steps up to the intermediate stage of the manufacturing method of the ceramic substrate 40 of the present embodiment.
  • the ceramic substrate 40 of the present embodiment is, for example, a rectangular plate (see FIGS. 3D, 3G, 3J, 3M, 3P, 5 and the like).
  • the green sheet forming step S1 includes a slurry manufacturing step S11, a molding step S12, a cutting step S13, a deposition step S14, and a degreasing step S15, and is performed in the order described in these steps (FIGS. 1 and S1). See FIG. 2A).
  • the slurry preparation step S11 will be described.
  • the raw material powder described later and an organic solvent are mixed to prepare a slurry 10.
  • the slurry 10 produced in this step (see FIG. 2B) is molded into a band-shaped green sheet 20 in the next step (molding step S12).
  • the raw material powder of the slurry 10 is a powder containing a main component and a sintering aid, which will be described later.
  • Main component is 80 wt% to 98.3 wt% of silicon nitride as an example (Si 3 N 4), sintering aid of at least one 1 wt% to 10 wt% as an example (as oxide) It is a rare earth element and 0.7% by mass to 10% by mass (oxide equivalent) of magnesium (Mg).
  • the pregelatinization rate of the silicon nitride powder is preferably 20% to 100% in consideration of the density, bending strength and thermal conductivity of the ceramic substrate 40.
  • the raw material powder of silicon nitride is Si 3 N 4 powder (also known as silicon nitride powder or an example of ceramic powder), the raw material powder of Mg is MgO powder, and the powder of rare earth element raw material is Y 2 O 3 powdered denoted.
  • the raw material powder of silicon nitride and the raw material powder of the sintering aid do not have to be Si 3 N 4 powder, Mg O powder and Y 2 O 3 powder, respectively.
  • the Si 3 N 4 powder, the Mg O powder and the Y 2 O 3 powder blended as described above are mixed with a plasticizer, an organic binder and an organic solvent to prepare a slurry 10. Therefore, the slurry 10 produced in this step contains ceramic powder.
  • the doctor blade forming apparatus 100 includes a belt conveying mechanism 110, a forming unit 120, and a heating unit 130.
  • the belt transport mechanism 110 has a roller 112A on the upstream side, a roller 112B on the downstream side, and a belt 114, and drives the roller 112 on the downstream side to move the belt 114 from the roller 112 on the upstream side to the roller 112 on the downstream side. Move (along the X direction).
  • the molding unit 120 is arranged on the upper side of the belt 114 (on the Z direction side of the belt 114) and faces the belt 114.
  • the molding unit 120 has an accommodating portion 122 accommodating the slurry 10 and a doctor blade 124.
  • the molding unit 120 is a sheet having a film thickness determined by regulating the slurry 10 taken out from the accommodating portion 122 by its own weight and the adhesive force with the moving belt 114 by the doctor blade 124. Make it into a shape.
  • the heating unit 130 blows warm air WC onto the slurry 10 on the belt 114 having a predetermined film thickness to form the slurry 10 into a sheet (vaporizes the organic solvent).
  • a band-shaped green sheet 20 having a width defined from the slurry 10 (the Y direction in the drawing corresponds to the width direction) is produced. That is, in the molding step S12, the slurry 10 is formed into a band by doctor blade molding to obtain a band-shaped green sheet 20 containing Si 3 N 4 (ceramic) as an example.
  • this step is performed after defoaming the slurry 10 produced in the slurry production step S11 and thickening the slurry 10.
  • the film thickness of the band-shaped green sheet 20 produced in this step is set in consideration of the film thickness of the ceramic substrate 40 finally produced.
  • the regulation conditions (distance from the belt 114, etc.) of the doctor blade 124 for regulating the slurry 10 to a predetermined film thickness are also set in consideration of the film thickness of the ceramic substrate 40 to be finally manufactured. Will be done.
  • the cutting step S13 of the strip-shaped green sheet 20 will be described.
  • the strip-shaped green sheet 20 is cut to produce a single-wafer green sheet 30.
  • the cutting device 200 includes a sheet transport mechanism 210 and a cutting portion 220.
  • the sheet transport mechanism 210 has a support portion 212, a first transport portion 214, and a second transport portion 216.
  • the support portion 212 rotatably supports the roller 112B (see FIGS. 2B and 2C) in which the strip-shaped green sheet 20 produced in the molding step S12 is wound around the outer peripheral surface.
  • the first transport portion 214 arranges the posture of the strip-shaped green sheet 20 transported from the support portion 212 and conveys the strip-shaped green sheet 20 to the cutting portion 220 along the X direction (along the longitudinal direction of the strip-shaped green sheet 20). To do.
  • the second transport section 216 transports the single-wafer green sheet 30 produced by cutting the strip-shaped green sheet 20 at the cutting section 220 further downstream (in the X direction).
  • the cutting portion 220 has a housing 222, an irradiation portion 224, and a moving mechanism 226.
  • the irradiation unit 224 irradiates the laser beam LB as an example.
  • the moving mechanism 226 scans the irradiation unit 224 from one end to the other end of the strip-shaped green sheet 20 in the lateral direction (Y direction in the drawing).
  • the irradiation unit 224 and the moving mechanism 226 are attached to the housing 222.
  • the strip-shaped green sheet 20 is conveyed by the sheet conveying mechanism 210 for the length of the single-wafer green sheet 30 to stop the strip-shaped green sheet 20, and the strip-shaped green sheet 20 is stopped by the cutting portion 220.
  • the cutting portion 220 moves the irradiation portion 224 along the Y direction from one end side to the other end side in the lateral direction of the band-shaped green sheet 20 by the moving mechanism 226, while the laser light LB is transferred to the irradiation portion 224. (See Fig. 2D).
  • the irradiation unit 224 scanned by the moving mechanism 226 intermittently irradiates the laser beam LB.
  • the moving mechanism 226 scans the irradiation unit 224 by causing the irradiation unit 224 to repeatedly move and stop (see FIG. 2D).
  • the band-shaped green sheet 20 is irradiated with the laser beam LB to cut the band-shaped green sheet 20 to obtain the single-wafer green sheet 30.
  • the laser light LB may be a carbon dioxide gas laser light, an infrared laser light, an ultraviolet laser light, or other laser light as long as the band-shaped green sheet 20 can be cut.
  • the strip-shaped green sheet 20 is cut by using the cutting device 200 shown in FIG. 2C to manufacture the single-wafer green sheet 30, but the single-leaf green sheet 30 is formed from the strip-shaped green sheet 20.
  • Other methods may be used as long as they can be produced.
  • a strip-shaped green sheet 20 may be punched out by a press using a press working apparatus (not shown) to produce a single-wafer green sheet 30.
  • the deposition step S14 will be described.
  • this step as shown in FIG. 3A, a plurality of single-wafer green sheets 30 are stacked in the thickness direction thereof. This step is performed in order to efficiently sinter the single-wafer green sheet 30 in a later step (sintering step S2).
  • a plurality of single-wafer green sheets 30 are deposited via a non-reactive powder layer (not shown) described later.
  • the number of sheets of the sheet-fed green sheets 30 that overlap each other is small, the number of sheets that can be processed at one time in the sintering furnace (not shown) in the subsequent sintering step S2 is small (the production efficiency is low).
  • the number of sheets of the sheet-fed green sheet 30 stacked is large, the binder contained in the sheet-fed green sheet 30 is less likely to be decomposed in the next step (defatting step S15).
  • the number of sheet-fed green sheets 30 to be stacked in this step is 8 to 100, preferably 30 to 70.
  • the non-reactive powder layer of the present embodiment is, for example, a boron nitride powder layer (BN powder layer) having a film thickness of about 1 ⁇ m to 20 ⁇ m.
  • the BN powder layer has a function of easily separating the ceramic substrate 40 after the next step (sintering step S2).
  • the BN powder layer is applied as a slurry of BN powder on one surface of each sheet-fed green sheet 30 by, for example, spraying, brush coating, roll coater, screen printing, or the like.
  • the BN powder has a purity of 85% or more, and preferably has an average particle size of 1 ⁇ m to 20 ⁇ m.
  • the degreasing step S15 will be described.
  • the binder and plasticizer contained in the single-wafer green sheet 30 are degreased before the next step (sintering step S2).
  • a plurality of single-wafer green sheets 30 (see FIG. 3A) stacked in the deposition step S14 are held in a temperature environment of 450 ° C. to 750 ° C. for 0.5 hours to 20 hours.
  • the binder and the plasticizer contained in the plurality of single-wafer green sheets 30 are degreased.
  • sintering step S2 will be described with reference to FIGS. 3A to 3R.
  • a plurality of single-wafer green sheets 30 (hereinafter referred to as a plurality of single-wafer green sheets 30 in FIG. 3A), which are stacked in the deposition step S14 and degreased by the binder and the plasticizer in the degreasing step S15, are baked. Sinter using a binder (not shown).
  • the sintering device includes a sintering furnace and a control device.
  • the sintering furnace has a temperature control mechanism, a firing chamber, and a thermometer for measuring the temperature in the firing chamber.
  • the temperature adjusting mechanism includes a temperature raising unit (as an example, a heater) for raising the temperature in the firing chamber and a cooling unit (for example, a water cooling pipe) for cooling the firing chamber.
  • the control device is a temperature adjusting mechanism so that the temperature in the firing chamber changes according to the temperature control program described later. To control.
  • the temperature control program is stored in a storage device (for example, ROM or the like) of the control device. Then, by using the temperature control program, the control device performs temperature control (for example, PID control, etc.) by the temperature adjusting mechanism while referring to the temperature information of the thermometer.
  • the temperature control program comprises a temperature profile in the firing chamber including a temperature raising region F1 having a slow heating region, a temperature holding region F2, and a cooling region F3, and the profile proceeds in the order described. (See FIG. 3B).
  • the technical significance of the temperature rising region F1, the temperature holding region F2, and the cooling region F3 will be described.
  • the temperature rise region F1 is a temperature region for the sintering aid contained in each single-wafer green sheet 30 to react with the oxide layer on the surface of the silicon nitride particles to form a liquid phase.
  • the temperature rising region F1 of the present embodiment is, for example, in about 12 hours from room temperature to a temperature within the range of 1600 ° C. to 2000 ° C. (in the case of the present embodiment, about 1800 ° C. as an example). It is preferable to raise the temperature in a specific manner.
  • the grain growth of ⁇ -type silicon nitride is suppressed, and the silicon nitride particles are rearranged and densified in the liquid-phased sintering aid.
  • a ceramic substrate 40 having a small pore diameter and a small porosity, a strong bending strength, and a high thermal conductivity can be obtained through the next temperature holding region F2.
  • the temperature holding region F2 is a ceramic substrate which is a sintered body by promoting rearrangement of silicon nitride particles, formation of ⁇ -type silicon nitride crystals, and grain growth of silicon nitride crystals from the liquid phase generated in the temperature rising region F1.
  • This is a temperature range for further densifying 40.
  • the temperature in the temperature holding range F2 is 1600 ° C. to 2000 ° C. in consideration of the size and aspect ratio (ratio of major axis to minor axis) of ⁇ -type silicon nitride particles, formation of pores due to volatilization of the sintering aid, and the like. It is preferable that the temperature is within the range of ° C.
  • the holding time is 1 hour to 30 hours (in the case of this embodiment, about 8 hours as an example).
  • the temperature of the temperature holding region F2 is less than 1600 ° C., the ceramic substrate 40 is difficult to be densified.
  • the sintering aid volatilizes and silicon nitride decomposes violently, making it difficult for the ceramic substrate 40 to become dense.
  • the temperature of the temperature holding region F2 may be set so as to change with time (for example, the temperature is gradually increased). May be set as).
  • the temperature of the temperature holding region F2 is more preferably a temperature in the range of 1750 ° C. to 1950 ° C., and further preferably a temperature in the range of 1800 ° C. to 1900 ° C. Further, the temperature of the temperature holding region F2 is preferably 50 ° C. or more higher than the upper limit of the temperature of the slow heat region F1, and more preferably 100 ° C. to 300 ° C. or more higher.
  • the holding time of the temperature holding region F2 is more preferably 2 hours to 20 hours, still more preferably 3 hours to 10 hours.
  • the cooling region F3 is a temperature region for cooling and solidifying the liquid phase maintained in the temperature holding region F2 and fixing the position of the obtained grain boundary phase.
  • the cooling region F3 of the present embodiment includes a quenching region F4 described later.
  • the cooling rate of the cooling region F3 is preferably 100 ° C./hour or more, more preferably 300 ° C./hour or more, and more preferably 500 ° C./hour, in order to rapidly solidify the liquid phase and maintain the uniformity of the grain boundary phase distribution. More than time is more preferred.
  • the practical cooling rate is preferably 500 ° C. to 600 ° C./hour.
  • the cooling region F3 is the temperature region after the temperature rising region F1 and the temperature holding region F2 in the temperature control program (see FIG. 3B). Therefore, the cooling region F3 of the present embodiment can be said to be a temperature region in which the firing chamber is cooled after the firing chamber is heated by the temperature raising region F1 and the temperature holding region F2 until the temperature in the firing chamber reaches at least 1600 ° C. ( See FIG. 3B).
  • the cooling region F3 of the present embodiment has a temperature region in which the cooling temperature rate is further increased in the middle of the progress.
  • this "temperature region in which the cooling rate is further increased" is referred to as a quenching region F4.
  • the quenching region F4 of the present embodiment is started when, for example, the temperature in the firing chamber reaches any temperature of 650 ° C. or lower.
  • the time for performing the quenching region F4 is, for example, about half or less of the time for performing the cooling region F3.
  • the technical significance of setting the quenching region F4 in the cooling region F3 (see FIGS. 3C to 3R, etc.) will be described later.
  • This step is a step (cutting step) of cutting a portion on the entire peripheral edge side of the ceramic substrate 40 manufactured through the sintering step S2.
  • a laser processing machine (not shown) is used to cut a portion having a width of 3 mm or less as an example of the entire peripheral edge side of the ceramic substrate 40 after the sintering step S2.
  • the laser light source of the laser processing machine intermittently irradiates the laser beam along the portion to be cut.
  • a scribing line composed of a plurality of dents arranged in a straight line at a predetermined interval p1 due to the scanning speed and irradiation time of the laser light source. SL is formed. Then, for example, when the defined interval p1 is 90 ⁇ m or more and 110 ⁇ m or less, microcracks MC (an example of cracks) are formed in the entire area from each recess in the plate thickness direction at the end (see FIG. 6B).
  • FIG. 6C shows a partial perspective view (here, a perspective view of a corner portion of a rectangle) in a state after cutting a predetermined width on the entire peripheral edge side with a scribe line SL.
  • the thickness T1 of the ceramic substrate 40 is 320 ⁇ m.
  • a plurality of dents are formed at the end portion (main surface end portion 40A3) of the surface 40A1 of the ceramic substrate 40 at the portion corresponding to the scribe line SL at the above interval p1.
  • a plurality of microcracks MC are formed from the recess of the main surface end portion 40A3 in the in-plane direction from one end (front surface 40A1) to the other end (back surface 40A2) in the plate thickness direction.
  • the length L11 of each microcrack MC (that is, the length L11 of the microcrack MC appearing to extend in the in-plane direction from the main surface end portion 40A3 on the main surface (that is, the surface 40A1)) is 15 as an example. It is ⁇ 25 ⁇ m. Further, the length L21 of the portion appearing on the end face 40A4 of the microcrack MC is 250 to 320 ⁇ m. From the above, when this step is completed, the ceramic substrate 40 is manufactured in which the entire peripheral edge portion is cut and a plurality of microcracks MC are formed over the entire circumferential direction of the end portion.
  • FIG. 3B is a graph showing a profile of the firing temperature in the sintering step S2 (including the conditions examined by the test).
  • the quenching region F4 is started.
  • FIG. 3C is a graph of the result, that is, a graph showing the relationship between the quenching start temperature in the sintering step S2 and the amount of warpage (the above-mentioned maximum high / low value). According to the graph of FIG. 3C, it can be seen that the lower the quenching start temperature, the smaller the amount of warpage of the ceramic substrate 40 tends to be.
  • the amount of warpage is preferably 6 ⁇ m or less at the maximum.
  • the reason is that it can be easily handled during the circuit pattern forming step (resist printing step S6 and etching step S7) or the electronic component mounting step S10.
  • the higher the quenching start temperature the larger the amount of warpage and the more the amount of warpage varies. This means that the higher the quenching start temperature, the greater the influence of the partial strain of the ceramic substrate 40 due to the quenching.
  • the quenching start temperature is 400 ° C.
  • the warp amount of the ceramic substrate 40 is less than the maximum permissible value of the warp amount even if the variation in the warp amount is taken into consideration. In the case of less than 4 ⁇ m).
  • the quenching start temperature is extremely lowered (for example, 400 ° C. or lower), the productivity is lowered due to the extension of the firing time. Therefore, in the present embodiment, considering the balance between the amount of warpage and the shortening of the firing time, the quenching start temperature of 400 ° C. to 650 ° C. is considered to be an appropriate range. If the shortening of the firing time is not taken into consideration, the quenching start temperature may be set to less than 400 ° C. The above is the technical significance of setting the quenching region F4 in the cooling region F3.
  • FIG. 4B is a graph of the result, that is, a graph showing the relationship between the cutting width of the outer peripheral portion and the amount of warpage in the outer peripheral portion cutting step S3. As can be seen from the graph of FIG.
  • the cutting width of the outer peripheral portion is narrow. Therefore, in the present embodiment, it is preferable that the cutting width of the outer peripheral portion is 3 mm or less.
  • a plurality of microcracks MC are formed on the entire circumference of the end portion of the ceramic substrate 40 of the present embodiment. The plurality of microcracks MC are arranged at intervals p1 defined in the circumferential direction of the end portion. Therefore, the permanent strain remaining in the vicinity of the end portion is easily released by the microcrack MC. That is, the tensile stress of the portion is released by deforming the microcrack MC so as to close the portion to which the tensile stress is applied.
  • the compressive stress of the portion is released by deforming the portion to which the compressive stress is applied so that the microcrack MC opens. From the above, it is considered that the plurality of microcracks MC formed at the end portion release the permanent strain in the vicinity of the end portion of the ceramic substrate 40, and as a result, the amount of warpage of the ceramic substrate 40 is reduced.
  • the above is the technical significance of performing the outer peripheral partial cutting step S3.
  • the above is the explanation of the outer peripheral partial cutting step S3.
  • the above is a description of the method for manufacturing the ceramic substrate 40 of the present embodiment.
  • SL forming step S4 will be described with reference to FIG.
  • a plurality of scribe lines SL three lines as an example in this embodiment
  • the ceramic substrate 40A with SL is manufactured.
  • a total of three straight lines, one in the center in the width direction and two in the length direction are divided into three equal parts by the laser beam irradiated from the irradiation portion (not shown) on the surface 40A1 of the ceramic substrate 40 as an example. Is formed, and the entire region of the surface 40A1 is divided into six equal parts.
  • each scribe line SL is composed of a plurality of dents arranged in a straight line (see FIG. 6B). Therefore, the irradiation unit (for example, a carbon dioxide laser light source, a YAG laser light source, etc.) used in this step can intermittently irradiate laser light, for example.
  • Each scribe line SL is used as a cutting line when the ceramic substrate 40 is divided into a plurality of (six in the present embodiment) in the dividing step S9 (see FIG. 1), which is a later step.
  • the metal layer forming step S5 will be described with reference to FIGS. 6A and 6B.
  • the first metal layer 50A and the second metal layer 50B are fixed to the front surface 40A1 side and the back surface 40A2 side of the ceramic substrate 40A with SL, respectively.
  • the first metal layer 50A and the second metal layer 50B are fixed to the front surface 40A1 side and the back surface 40A2 side, respectively, via a brazing material (not shown).
  • a paste-like brazing material is uniformly applied to the front surface 40A1 and the back surface 40A2 of the ceramic substrate 40 by a method such as a roll coater method, a screen printing method, or a transfer method, and further, the paste-like material is uniformly applied.
  • the first metal layer 50A and the second metal layer 50B are joined to the front surface 40A1 and the back surface 40A2 of the ceramic substrate 40 via a brazing material, respectively.
  • the screen printing method is preferable in that the paste-like brazing material is uniformly applied. Further, in this case, it is preferable to control the clay of the paste-like brazing material to 5 Pa ⁇ s to 20 Pa ⁇ s.
  • FIG. 6B illustrates a state in which microcracks MC extending from each of the plurality of dents constituting the scribe line SL to the back surface 40A2 are formed. It is formed.
  • the microcrack MC is also formed during the above-mentioned outer peripheral portion cutting step S3.
  • the resist printing step S6 will be described with reference to FIG. 7.
  • the first metal layer 50A of the motherboard 60 is coated with a photosensitive resist film PRF, and the six regions defined by the three scribing lines SL in the first metal layer 50A are each circuit described later.
  • a resist pattern PRP corresponding to the pattern CP is formed.
  • an exposure apparatus (not shown) is used to print a resist pattern PRP on the resist film PRF (the resist pattern PRP is cured, and a portion of the resist film PRF other than the resist pattern PRP is printed. Leave uncured).
  • the motherboard 60A with PRP is manufactured.
  • the etching step S7 (an example of the circuit pattern forming step) will be described with reference to FIG.
  • the uncured resist film PRF in the resist film PRF of the motherboard 60A with PRP is removed, the exposed portion of the first metal layer 50A is etched, and then the remaining resist pattern PRP is removed to remove the circuit pattern CP.
  • the motherboard 60A with PRP before this step becomes a collective substrate 60B in which the circuit pattern CP is formed in each of the six regions partitioned by the three scribe lines SL. Further, when the assembly substrate 60B is formed, all the portions of the three scribe lines SL formed in the SL forming step S4 are exposed as the first metal layer 50A is etched.
  • etching step S7 is taken as an example of the circuit pattern forming step, but the combination of the resist printing step S6 and the etching step S7 may be regarded as an example of the circuit pattern forming step.
  • a protective layer such as a solder resist is formed on the surface of the assembly substrate 60B on the side where a plurality of circuit pattern CPs (six in this embodiment) are formed, except for the bonding portion where the electronic components are bonded. (Not shown) is covered, and the surface treatment of the portion other than the joint portion is performed. Further, in this step, the joint portion to which the electronic component is joined is plated by, for example, an electrolytic plating method, and the surface treatment of the joint portion is performed.
  • the product at the end of the etching step S7 is the assembly substrate 60B, but the product at the end of the surface treatment step S8, that is, the substrate in which the assembly substrate 60B is coated with the protective layer is assembled. You may think of it as a substrate.
  • a division step S9 will be described with reference to FIG.
  • a plurality of assembly boards 60B (or ceramic substrates 40A with SL) are cut along a plurality of (three as an example in this embodiment) scribing line SL, and a plurality of assembly boards 60B (one example in this embodiment) are cut. 6 sheets) are divided into circuit boards 60C.
  • the first metal layer 50A becomes the circuit pattern CP of each circuit board 60C by the steps so far.
  • the region partitioned by the three scribe lines SL is the metal on the side opposite to the side on which the circuit pattern CP is formed in each circuit board 60C by the steps so far.
  • the metal layer functions as a heat radiating layer for radiating heat generated by electronic components mounted on the circuit pattern CP when the mounting board (not shown) manufactured in the mounting step S10 described later is used. ..
  • the end portion of each circuit board 60B formed by the division is divided into the outer peripheral portion cutting step S3 as in the case of the outer peripheral portion cutting step S3.
  • a plurality of microcracks MC are formed. That is, when focusing on the ceramic substrate 40 of the circuit board 60B, a plurality of microcracks MCs having a mode as shown in FIG. 6C are formed. Therefore, when this step is completed, the amount of warpage of each circuit board 60B after division is reduced as compared with the amount of warpage of each circuit board 60C in the state (before division) of the assembly board 60B.
  • the metal layer forming step S5 is performed on the motherboard 60, and then the dividing step S9 is performed.
  • the surface treatment step S8 may be performed from the metal layer forming step S5 after the step S9 is performed.
  • the mounting step S10 will be described.
  • electronic components (not shown) are mounted on each circuit board 60C (see FIG. 9).
  • a mounting device (not shown) is used to attach solder (not shown) to a joint portion where electronic components are joined in the circuit pattern CP (see FIG. 9) of each circuit board 60C, and the joint portion is attached.
  • the deformation of each circuit board 60C due to heat generation at the time of joining causes the opening and closing operation of the microcracks MC.
  • the positional deviation between the joint portion of the circuit pattern CP and the joint terminal of the electronic component at the time of joining is suppressed by the opening / closing operation of the microcrack MC.
  • this step is a step after the split step S9, but the split step S9 may be performed after the main step. That is, the manufacturing method S100 of the present embodiment may be performed in the order of the mounting step S10 and the dividing step S9 after the surface treatment step S8.
  • an inspection device (not shown) is used to inspect the circuit pattern CP, inspect the operation of electronic components, and the like.
  • the above is the description of the manufacturing method S100 of the present embodiment.
  • the ceramic substrate 40 of the present embodiment (see FIGS. 3A, 3D, 3G, 3J, 3M, 3P, etc.) is a rectangular ceramic substrate 40 in a plan view, and is a diagonal line of the ceramic substrate 40.
  • the value obtained by dividing the maximum height difference of the ceramic substrate 40 in the plate thickness direction by the length is 1 ⁇ m / mm or less, and the plate thickness is at the end thereof in the in-plane direction from the main surface end portion 40A3 of the ceramic substrate 40.
  • a plurality of microcracks MC are formed from one end to the other end in the direction. Then, as described above, the ceramic substrate 40 of the present embodiment is processed into a circuit board 60C (see FIG.
  • the ceramic substrate 40 of the present embodiment extends from one end to the other end in the thickness direction (Z direction) of the ceramic substrate 40 in the in-plane direction from the main surface end portion 40A3 of the ceramic substrate 40 at its end (outer peripheral surface).
  • a plurality of microcracks MC are formed. Then, each microcrack MC functions to release, that is, reduce the strain energy in the vicinity of the outer peripheral edge of the ceramic substrate 40.
  • the ceramic substrate 40 of the present embodiment includes the ceramic substrates 40 of the first to fifth examples (see FIGS. 3A, 3D, 3G, 3J, 3M, 3P, etc.) and others.
  • the ceramic substrate 40 of the present embodiment has a maximum height value of 1 ⁇ m or less. Then, the end portion (outer peripheral surface) of the ceramic substrate 40 of the present embodiment extends from one end to the other end in the plate thickness direction (Z direction) in the in-plane direction from the main surface end portion 40A3 of the ceramic substrate 40. A plurality of microcracks MC are formed (see FIGS. 6B and 6C).
  • the ceramic substrate 40 of the present embodiment can maintain the maximum height value of 1 ⁇ m or less by the above-mentioned functions of the plurality of microcracks MC in any of the above cases. Therefore, by using the ceramic substrate 40 of the present embodiment, it is possible to produce a highly reliable circuit board having excellent flatness in which residual thermal strain and residual thermal stress are remarkably reduced.
  • the plurality of microcracks MC are arranged at intervals p1 defined in the circumferential direction of the end portion of the ceramic substrate 40. Therefore, by using the ceramic substrate 40 of the present embodiment, it is possible to produce a highly reliable circuit board having excellent flatness in which residual thermal strain and residual thermal stress are remarkably reduced over the entire circumference thereof in a well-balanced manner.
  • a plurality of microcracks MC are not simply arranged in the circumferential direction of the end portion of the ceramic substrate 40, but are arranged at intervals of 90 ⁇ m or more and 110 ⁇ m or less, and a plurality.
  • the length L11 of the microcrack MC of the book (that is, the length L11 of the microcrack MC appearing to extend in the in-plane direction from the main surface end 40A3 of the surface 40A1 which is the main surface) is 15 ⁇ m or more and 25 ⁇ m or less. Therefore, if the ceramic substrate 40 of the present embodiment is used, the above-mentioned third effect can be exhibited more remarkably.
  • the motherboard 60 of this embodiment has a ceramic substrate 40, a first metal layer 50A fixed to the front surface 40A1 side of the ceramic substrate 40, and a back surface 40A2 side of the ceramic substrate 40.
  • the ceramic substrate 40 included in the motherboard 60 of the present embodiment has the above-mentioned first to fourth effects. Therefore, the motherboard 60 of the present embodiment is provided with the ceramic substrate 40 of the present embodiment, so that the residual thermal strain and the residual thermal stress are remarkably reduced and the flatness is excellent.
  • the circuit board 60C of the present embodiment includes a ceramic substrate 40 and a circuit pattern CP formed on one surface side of the ceramic substrate 40 (in this embodiment, the surface 40A1 side as an example).
  • a metal layer (second metal layer 50) fixed to the other surface side of the ceramic substrate 40 (in the present embodiment, the back surface 40A2 side as an example) is provided.
  • the ceramic substrate 40 included in the circuit board 60C of the present embodiment has the above-mentioned first to fourth effects. Therefore, the circuit board 60C of the present embodiment is provided with the ceramic substrate 40 of the present embodiment, so that the residual thermal strain and the residual thermal stress are remarkably reduced and the flatness is excellent.
  • the method for manufacturing the ceramic substrate 40 of the present embodiment includes a cutting step of cutting the strip-shaped green sheet 20 containing the ceramic powder to obtain the single-wafer green sheet 30, and arranging the single-leaf green sheet 20 in the firing chamber.
  • a cutting step of cutting the entire peripheral edge side portion of the cooled ceramic substrate 40 is included.
  • the portion of the ceramic substrate 40 in the vicinity of the outer peripheral edge where a large amount of strain energy remains due to the influence of cooling is cut.
  • the ceramic substrate 40 whose entire peripheral edge is cut is released from a state in which compressive stress or tensile stress is applied due to the influence of cooling, that is, stress of the outer peripheral edge in particular.
  • the method for manufacturing the ceramic substrate 40 of the present embodiment it is possible to manufacture the ceramic substrate 40 in which the residual thermal strain and the residual thermal stress are remarkably reduced and the flatness is excellent (see FIG. 4B). ..
  • the ceramic in the cutting step, is intermittently irradiated with laser light while scanning the laser light source over the entire circumference of the entire peripheral edge side of the ceramic substrate 40 in the circumferential direction.
  • a microcrack MC is formed at an end portion formed by cutting the substrate 40. Therefore, when the ceramic substrate 40 is cut along the scribe line SL, one end in the plate thickness direction (Z direction) of the ceramic substrate 40 in the in-plane direction from the main surface end portion 40A3 of the ceramic substrate 40 is formed at the end portion formed by the cutting.
  • a plurality of microcracks MC are formed from the to the other end.
  • the plurality of microcracks MC function to release, that is, reduce the strain energy in the vicinity of the outer peripheral edge of the ceramic substrate 40. Therefore, according to the method for manufacturing the ceramic substrate 40 of the present embodiment, it is possible to manufacture the ceramic substrate 40 having excellent flatness in which residual thermal strain and residual thermal stress are remarkably reduced.
  • the quenching region F4 is performed in the cooling region F3 of the sintering step S2 (see FIG. 3B).
  • the quenching start temperature for performing the quenching region F4 is set to 650 ° C. or lower as an example (see FIG. 3B).
  • the outer peripheral portion cutting step S3 (see FIGS. 1, 4A and 4B) is performed while performing the quenching region F4 in the cooling region F3 of the sintering step S2. Therefore, it is possible to manufacture the ceramic substrate 40 having excellent flatness in which residual thermal strain and residual thermal stress are remarkably reduced.
  • examples of the ceramic substrates 40 are referred to as Examples 1 to 5 (see FIGS. 3D to 3R).
  • an example of the ceramic substrate 40 may be, for example, the ceramic substrate 40 of the second modification shown in FIGS. 11A to 11C.
  • FIGS. 11A to 11C Only the parts different from the above-described embodiment in the present modification will be described with reference to FIGS. 11A to 11C.
  • FIG. 11A is a plan view of the ceramic substrate 40 of the present modification, and is a height distribution diagram with a profile of the degree of height (recession) in the plate thickness direction (Z direction).
  • FIG. 11B is a cross-sectional view of the ceramic substrate 40 of FIG. 11A, which is a vertical cross-sectional view (X 0- X 0 cross section) cut along the X 0- X 0 cutting line and a vertical section cut along the X 1- X 1 cutting line.
  • rear view (X 1 -X 1 section) and X 2 -X 2 cut longitudinal section taken along the line diagram of (X 2 -X 2 section), diagrams arranged respectively along the X direction.
  • 11C is a cross-sectional view of the ceramic substrate 40 of FIG. 11A, which is a cross-sectional view cut along the Y 0- Y 0 cutting line, a cross-sectional view cut along the Y 1- Y 1 cutting line, and Y 2- Y 2 It is the figure which arranged the cross-sectional view cut by the cutting line along the Y direction, respectively.
  • the ceramic substrate 40 of this modified example has the following features.
  • the ceramic substrate 40 of this modification is formed by a pair of diagonal lines when the intersection O formed by the pair of diagonal lines (broken line in FIG. 11A) is used as a reference in the plate thickness direction of the ceramic substrate 40 in a plan view.
  • one of the pair of the first region and the pair of the second regions facing each other across the intersection O is located on one side of the intersection O in the plate thickness direction, and the other is the plate thickness of the intersection O. It is located on the other side of the direction.
  • the maximum height value is 1 ⁇ m / mm or less.
  • the cut surface (first cut surface) cut along the straight line L1 in the Y direction passing through the center O is a circle in which the portion of the center O is convex on one side in the plate thickness direction. It has an arc shape.
  • the first cut surface forms an arc-shaped surface in which the position of the central O portion serves as an inflection point and becomes convex on one side in the plate thickness direction.
  • the first cut surface has an arcuate shape in which the position of the center O portion is the position on one side of the plate thickness direction and is convex on one side in the plate thickness direction. Forming a surface.
  • the convex amount of the convex portion of the central O portion (the amount of the convex or concave portion as compared with the flat case ((reference in the figure))) is defined as ⁇ Z 1 .
  • the convex amount becomes smaller as ⁇ Z 2 ( ⁇ Z 1 ) and ⁇ Z 3 ( ⁇ Z 2).
  • the convex amount ⁇ Z 1 is 252 ⁇ m or less as an example. Further, as shown in FIG.
  • the cut surface (second cut surface) cut along the straight line L2 in the X direction passing through the center O has an arc shape in which the portion of the center O is convex toward the other side in the plate thickness direction. Is made up of.
  • the second cut surface forms an arc-shaped surface in which the position of the central O portion serves as an inflection point and becomes convex on the other side in the plate thickness direction.
  • the second cut surface has an arc shape in which the position of the center O portion is the position on the other side in the plate thickness direction and is convex toward the other side in the plate thickness direction. Forming a surface.
  • the convex amount of the convex portion of the central O portion (the amount of the convex or concave portion as compared with the flat case) is defined as ⁇ Z 1 .
  • the convex amount increases to ⁇ Z 2 (> ⁇ Z 1 ) and ⁇ Z 3 (> ⁇ Z 2 ).
  • the convex amount ⁇ Z 1 is 252 ⁇ m or less as an example.
  • the ceramic substrate 40 of this modification is in a warped state that is line-symmetric with respect to the straight line L1 and the straight line L2 described later.
  • the ceramic substrate 40 of this modification has a three-dimensional shape that is line-symmetric with respect to the straight line L1 and the straight line L2. From the above, in the ceramic substrate 40 of the present modification, the maximum convex amount is 252 ⁇ m or less and the diagonal length is about 252.5 mm, so that the maximum height value is 1 ⁇ m / mm or less.
  • the ceramic substrate 40 of the present modification is cut by a first straight line (an example of the first straight line) that passes through the center O and is parallel to any one of the four sides in the plan view of the ceramic substrate 40.
  • the central portion of the cut surface in the length direction (Y direction) is curved in a convex shape toward one side in the plate thickness direction (see FIG. 11B).
  • the second cut surface cut by the straight line L2 (an example of the second straight line) passing through the center O and orthogonal to the straight line L1 has a central portion in the length direction convex toward the other side in the plate thickness direction. (See FIG. 11C), and its maximum height is 1 ⁇ m / mm or less.
  • the ceramic substrate 40 of this modified example is parallel to the first cut surface (X 0- X 0 cross section) at each position extending from both ends of the ceramic substrate 40 in the direction (Y direction) along the straight line L1 from the center O.
  • first parallel cut surfaces (X 1 -X 1 section and X 2 -X 2 section of FIG. 11B) the central portion of each length direction is curved in a convex shape toward the one side in the thickness direction, the The first parallel cut surface at each position has a continuous increase in curvature from the center O to both ends of the ceramic substrate 40 in the direction along the straight line L1 (X direction) (see FIG. 11B).
  • the ceramic substrate 40 of the present modification is a second parallel cut surface parallel to the second cut surface at each position extending from both ends of the ceramic substrate 40 in the direction (X direction) along the straight line L2 from the center O (FIG. 11C).
  • X 1 -X 1 section and X 2 -X 2 section) of the central portion of each length direction is convexly curved toward the other side of the plate thickness direction, wherein the second parallel cleavage at each position
  • the surface has a continuously small curvature from the center O to both ends of the ceramic substrate 40 in the direction along the straight line L1 (Y direction) (see FIG. 11C).
  • the above is the explanation of the features of the ceramic substrate 40 of this modified example.
  • the ceramic substrate 40 of the present modification has these characteristics, and thus constitutes a so-called saddle-shaped substrate in which the center O is a saddle point.
  • an example of ceramic powder has been described as silicon nitride.
  • an example of the ceramic powder may be another ceramic powder.
  • aluminum nitride powder may be used.
  • the molding step S12 (see FIG. 2A) included in the green sheet forming step S1 of the present embodiment, it is assumed that the doctor blade molding is used. However, if the slurry 10 can be molded into the band-shaped green sheet 20, the molding step S12 may be performed by another method. For example, the molding step S12 may be performed by extrusion molding.
  • the irradiation unit 224 is moved from one end side to the other end side of the strip-shaped green sheet 20 in the lateral direction.
  • the strip-shaped green sheet 20 can be cut to obtain the single-wafer green sheet 30 as a result, the cut portion of the strip-shaped green sheet 20 is one end side of the strip-shaped green sheet 20 in the lateral direction as in the case of the present embodiment. It does not have to be a straight portion extending from the other end to the other end.
  • the strip-shaped green sheet 20 is cut so as to separate (or hollow out) the single-leaf green sheet 30 from the strip-shaped green sheet 20 by making a hole in the strip-shaped green sheet 20 in the shape of the single-leaf green sheet 30.
  • the single-wafer green sheet 30 obtained by cutting the strip-shaped green sheet 20 may have at least a part of all end faces thereof as a cut surface.
  • the circuit pattern CP is formed on the first metal layer 50A.
  • the circuit pattern CP may be formed on the second metal layer 50B without forming the circuit pattern CP on the first metal layer 50A. That is, in the pattern forming step (resist printing step S6 and etching step S7), at least one circuit pattern CP may be formed on either the first metal layer 50A or the second metal layer 50B.
  • the scribe line SL has been described as having a plurality of dents arranged in a straight line (see FIG. 6B).
  • the scribe line SL may be, for example, a continuous groove, a plurality of dents having different lengths, widths, etc., as long as the function can be exhibited.
  • the plurality of scribe lines SL has been described as being three scribe lines SL (see FIG. 5). However, the number of the plurality of scribe lines SL may be at least one or more.
  • the plurality of scribe lines SL divide the motherboard 60 into six equal parts (see FIG. 5). However, the plurality of scribe lines SL do not have to divide the motherboard 60 into equal parts.

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Abstract

This ceramic substrate has a rectangular shape in a plane view. A value obtained by dividing the maximum height difference of the ceramic substrate by the length of a diagonal of the ceramic substrate is 1 μm/mm or less. A plurality of cracks are formed in the end portions of the ceramic substrate so as to extend in an in-plane direction from a main surface end portion of the ceramic substrate and span from one end to the other end in the substrate thickness direction.

Description

セラミック基板、複合基板及び回路基板並びにセラミック基板の製造方法、複合基板の製造方法、回路基板の製造方法及び複数の回路基板の製造方法Ceramic substrate, composite substrate and circuit board, ceramic substrate manufacturing method, composite substrate manufacturing method, circuit board manufacturing method, and multiple circuit board manufacturing methods
　本発明は、セラミック基板、複合基板及び回路基板並びにセラミック基板の製造方法、複合基板の製造方法、回路基板の製造方法及び複数の回路基板の製造方法に関する。 The present invention relates to a ceramic substrate, a composite substrate, a circuit board, a method for manufacturing a ceramic substrate, a method for manufacturing a composite substrate, a method for manufacturing a circuit board, and a method for manufacturing a plurality of circuit boards.
　例えば、特許文献１のように、セラミック基板の両面側に金属層を固定して複合基板とし、この複合基板の一方の金属層に回路パターンを形成して回路基板にすることが知られている。この回路基板は、高熱伝導率、高絶縁性の観点において優れていることから、例えばパワーモジュール用に利用されている。 For example, as in Patent Document 1, it is known that metal layers are fixed on both sides of a ceramic substrate to form a composite substrate, and a circuit pattern is formed on one metal layer of the composite substrate to form a circuit board. .. This circuit board is used for, for example, a power module because it is excellent in terms of high thermal conductivity and high insulation.
　このようなセラミック基板は、その後、その両面側に金属層（例えば銅板）を固定する金属層形成工程、金属層の少なくとも一方に回路パターンを形成する回路パターン形成工程及びスクライブライン形成工程を含む各工程を経て回路基板に加工される。
　このような各工程においては、互いに熱膨張率が異なるセラミック基板と銅板とが接合された状態で種々の熱履歴が加わることとなるため、最終的に得られる回路基板の内部にはある程度の熱歪みや熱応力が残留することが避けられない。 Each such a ceramic substrate includes a metal layer forming step of fixing a metal layer (for example, a copper plate) on both sides thereof, a circuit pattern forming step of forming a circuit pattern on at least one of the metal layers, and a scribing line forming step. It is processed into a circuit board through a process.
In each of these steps, various thermal histories are added in a state where the ceramic substrate and the copper plate, which have different coefficients of thermal expansion, are joined to each other. Therefore, a certain amount of heat is added to the inside of the finally obtained circuit board. It is inevitable that strain and thermal stress will remain.
特開２０１８－１８９７１号公報Japanese Unexamined Patent Publication No. 2018-18971
　ところで、近年では、回路基板の平坦性に対する要請がますます高まりつつある。こうした要請に応えるためには、回路基板の内部に残留する熱歪みや熱応力を、より高い水準で低減することが求められる。 By the way, in recent years, the demand for flatness of circuit boards has been increasing more and more. In order to meet these demands, it is required to reduce the thermal strain and thermal stress remaining inside the circuit board at a higher level.
　本発明は、残留熱歪みや残留熱応力が顕著に低減された平坦性に優れる回路基板を作製し得るセラミック基板を提供することを課題とする。 An object of the present invention is to provide a ceramic substrate capable of producing a circuit board having excellent flatness in which residual thermal strain and residual thermal stress are remarkably reduced.
　本発明の第１態様のセラミック基板は、平面視にて矩形状のセラミック基板であって、前記セラミック基板の対角線の長さで前記セラミック基板の板厚方向における最大高低差を除した値は、１μｍ／ｍｍ以下であり、その端部には、前記セラミック基板の主面端部から面内方向に、板厚方向の一端から他端に亘る、複数本のクラックが形成されている。 The ceramic substrate of the first aspect of the present invention is a ceramic substrate having a rectangular shape in a plan view, and the value obtained by dividing the maximum height difference in the plate thickness direction of the ceramic substrate by the diagonal length of the ceramic substrate is It is 1 μm / mm or less, and a plurality of cracks are formed at the end thereof from one end to the other end in the plate thickness direction in the in-plane direction from the main surface end portion of the ceramic substrate.
　本発明の第２態様のセラミック基板は、前記セラミック基板であって、前記複数本のクラックは、前記端部の全周に亘って形成されている。 The ceramic substrate of the second aspect of the present invention is the ceramic substrate, and the plurality of cracks are formed over the entire circumference of the end portion.
　本発明の第３態様のセラミック基板は、前記セラミック基板であって、窒化珪素又は窒化アルミニウムを含む。 The ceramic substrate of the third aspect of the present invention is the ceramic substrate and includes silicon nitride or aluminum nitride.
　本発明の一態様の複合基板は、前記セラミック基板と、前記セラミック基板の表面側に固定されている第１金属層と、前記セラミック基板における裏面側に固定されている第２金属層と、を備える。 The composite substrate of one aspect of the present invention includes the ceramic substrate, a first metal layer fixed to the front surface side of the ceramic substrate, and a second metal layer fixed to the back surface side of the ceramic substrate. Be prepared.
　本発明の一態様の回路基板は、前記セラミック基板と、前記セラミック基板の表面側に形成されている回路パターンと、前記セラミック基板における裏面側に固定されている金属層と、を備える。 The circuit board of one aspect of the present invention includes the ceramic substrate, a circuit pattern formed on the front surface side of the ceramic substrate, and a metal layer fixed to the back surface side of the ceramic substrate.
　本発明の第１態様のセラミック基板の製造方法は、前記セラミック基板の製造方法であって、セラミック粉末を含む帯状グリーンシートを切断して枚葉グリーンシートを得る帯状グリーンシートの切断工程と、焼成室内に前記枚葉グリーンシートを配置して、前記焼成室内の温度が少なくとも１６００℃以上になるまで前記焼成室内を加熱した後に前記焼成室内を冷却し、前記枚葉グリーンシートを焼結させて前記セラミック基板を得る焼結工程と、前記焼結工程の後に冷却した前記セラミック基板の全周縁側の部分を切断するセラミック基板の切断工程と、を含む。 The method for producing a ceramic substrate according to the first aspect of the present invention is the method for producing a ceramic substrate, which is a step of cutting a strip-shaped green sheet containing a ceramic powder to obtain a single-wafer green sheet, and firing. The single-wafer green sheet is placed in the chamber, the firing chamber is heated until the temperature in the firing chamber reaches at least 1600 ° C., and then the firing chamber is cooled, and the single-wafer green sheet is sintered to obtain the above. It includes a sintering step of obtaining a ceramic substrate, and a cutting step of the ceramic substrate that cuts a portion of the ceramic substrate cooled on the entire peripheral edge side after the sintering step.
　本発明の第２態様のセラミック基板の製造方法は、前記セラミック基板の製造方法であって、前記セラミック基板の切断工程では、レーザー光源を前記セラミック基板の全周縁側の部分の周方向全周に亘って走査させながらレーザー光を間欠的に照射させて前記セラミック基板を切断することでできた端部にクラックを形成する。 The method for manufacturing a ceramic substrate according to the second aspect of the present invention is the method for manufacturing the ceramic substrate, and in the step of cutting the ceramic substrate, the laser light source is applied to the entire circumference of the portion on the entire peripheral edge side of the ceramic substrate in the circumferential direction. A crack is formed at the end portion formed by cutting the ceramic substrate by intermittently irradiating the ceramic substrate with a laser beam while scanning the ceramic substrate.
　本発明の第３態様のセラミック基板の製造方法は、前記セラミック基板の製造方法であって、前記焼結工程では、前記焼成室内の冷却時に前記焼成室内の温度が６５０℃以下の温度になった場合に前記焼成室内の温度を急冷する。 The method for manufacturing the ceramic substrate according to the third aspect of the present invention is the method for manufacturing the ceramic substrate. In the sintering step, the temperature in the firing chamber becomes 650 ° C. or lower when the firing chamber is cooled. In some cases, the temperature in the firing chamber is rapidly cooled.
　本発明の第４態様のセラミック基板の製造方法は、前記セラミック基板の製造方法であって、前記セラミック粉末は、窒化珪素粉末又は窒化アルミニウム粉末を含む。 The method for producing a ceramic substrate according to the fourth aspect of the present invention is the method for producing a ceramic substrate, and the ceramic powder includes silicon nitride powder or aluminum nitride powder.
　本発明の一態様の複合基板の製造方法は、前記セラミック基板の製造方法と、前記セラミック基板の表面側に第１金属層を固定し、裏面側に第２金属層を固定する固定工程と、を含む。 The method for manufacturing a composite substrate according to one aspect of the present invention includes a method for manufacturing the ceramic substrate, a fixing step of fixing the first metal layer on the front surface side of the ceramic substrate, and fixing the second metal layer on the back surface side. including.
　本発明の一態様の回路基板の製造方法は、前記複合基板の製造方法と、前記第１金属層及び前記第２金属層のいずれか一方に、少なくとも１つの回路パターンを形成するパターン形成工程と、を含む。 The method for manufacturing a circuit board according to one aspect of the present invention includes a method for manufacturing the composite substrate and a pattern forming step for forming at least one circuit pattern on either the first metal layer or the second metal layer. ,including.
　本発明の一態様の複数の回路基板の製造方法は、前記複合基板の製造方法と、前記第１金属層及び前記第２金属層のいずれか一方に、複数の回路パターンを形成するパターン形成工程と、前記複数の回路パターンが形成された前記複合基板を、それぞれが１つの前記回路パターンを備える複数の回路基板に分割する分割工程と、を含む。 The method for manufacturing a plurality of circuit boards according to one aspect of the present invention is a pattern forming step of forming a plurality of circuit patterns on either the method for manufacturing the composite substrate and the first metal layer and the second metal layer. And a division step of dividing the composite substrate on which the plurality of circuit patterns are formed into a plurality of circuit boards each having one of the circuit patterns.
　本発明のセラミック基板によれば、その後の金属層形成工程、金属層の少なくとも一方に回路パターンを形成する回路パターン形成工程及びスクライブライン形成工程を含む各工程を経た後に作製される、セラミック基板と金属層とが接合された接合基板及び回路基板の反りや内部応力を有効に低減できる。これに伴い、本発明のセラミック基板及び本発明のセラミック基板を備える複合基板によれば、残留熱歪みや残留熱応力が顕著に低減された平坦性に優れる回路基板を作製し得る。さらにこれに伴い、本発明の回路基板は、残留熱歪みや残留熱応力が顕著に低減された平坦性に優れる高い信頼性を有する。
　本発明のセラミック基板を用いて回路基板を作製すれば、残留熱歪みや残留熱応力が顕著に低減された平坦性に優れる高い信頼性の回路基板が得られる。 According to the ceramic substrate of the present invention, a ceramic substrate produced after going through each step including a subsequent metal layer forming step, a circuit pattern forming step of forming a circuit pattern on at least one of the metal layers, and a scribing line forming step. Warpage and internal stress of the bonded substrate and circuit board to which the metal layer is bonded can be effectively reduced. Along with this, according to the ceramic substrate of the present invention and the composite substrate including the ceramic substrate of the present invention, it is possible to produce a circuit board having excellent flatness in which residual thermal strain and residual thermal stress are remarkably reduced. Further, along with this, the circuit board of the present invention has high reliability with excellent flatness in which residual thermal strain and residual thermal stress are remarkably reduced.
When a circuit board is manufactured using the ceramic substrate of the present invention, a highly reliable circuit board having excellent flatness with remarkably reduced residual thermal strain and residual thermal stress can be obtained.
本実施形態の複数の実装基板の製造方法を示すフロー図である。It is a flow chart which shows the manufacturing method of the plurality of mounting boards of this embodiment. 本実施形態の複数の実装基板の製造方法に含まれる、グリーンシート形成工程のフロー図である。It is a flow chart of the green sheet forming process included in the manufacturing method of the plurality of mounting substrates of this embodiment. 本実施形態のグリーンシート形成工程に含まれる、成形工程を説明するための図であって、ドクターブレード成形装置を用いてスラリーから帯状グリーンシートを作製している状態を説明するための概略図である。It is a figure for demonstrating the molding process included in the green sheet forming process of this embodiment, and is the schematic figure for demonstrating the state which the band-shaped green sheet is produced from a slurry using a doctor blade molding apparatus. is there. 本実施形態のグリーンシート形成工程に含まれる、切断工程を説明するための図であって、切断装置を用いて帯状グリーンシートを切断して枚葉グリーンシートを作製している状態を説明するための概略図（側面図）である。It is a figure for demonstrating the cutting process included in the green sheet forming process of this embodiment, and is for demonstrating the state which cuts a strip-shaped green sheet using a cutting apparatus to produce a single-wafer green sheet. It is a schematic view (side view) of. 図２Ｃを正面側から見た概略図である。FIG. 2C is a schematic view of FIG. 2C viewed from the front side. 本実施形態のグリーンシート形成工程に含まれる堆積工程から本実施形態の複数の実装基板の製造方法における焼結工程までを説明するための図である。It is a figure for demonstrating from the deposition process included in the green sheet forming process of this embodiment to the sintering process in the manufacturing method of a plurality of mounting substrates of this embodiment. 焼結工程における焼成温度のプロファイル（試験により検討した条件も含む。）を示すグラフである。It is a graph which shows the profile of the firing temperature in the sintering process (including the condition examined by the test). 焼成工程における急冷開始温度（試験により検討した条件も含む。）と、反り量との関係を示すグラフである。It is a graph which shows the relationship between the quenching start temperature in a firing process (including the condition examined by a test), and the amount of warpage. 本実施形態の第１例のセラミック基板の平面図であって、その板厚方向における高低度合（凹み具合）のプロファイルを付した状態の高低分布図である。It is a top view of the ceramic substrate of the 1st example of this embodiment, and is the height distribution map in the state which the profile of the degree of height (the degree of dent) in the thickness direction is attached. 図３Ｄの第１例のセラミック基板の断面図であって、Ａ－Ａ切断線で切断した断面図である。It is sectional drawing of the ceramic substrate of the 1st example of FIG. 3D, and is the sectional view cut by the AA cutting line. 図３Ｄの第１例のセラミック基板の断面図であって、Ｂ－Ｂ切断線で切断した断面図である。FIG. 3 is a cross-sectional view of the ceramic substrate of the first example of FIG. 3D, which is a cross-sectional view cut along a BB cutting line. 本実施形態の第２例のセラミック基板の平面図であって、その板厚方向における高低度合（凹み具合）のプロファイルを付した状態の高低分布図である。It is a top view of the ceramic substrate of the 2nd example of this embodiment, and is the high-low distribution map in the state which the profile of the high-low degree degree (the degree of dent) in the plate thickness direction is attached. 図３Ｇの第２例のセラミック基板の断面図であって、Ａ－Ａ切断線で切断した断面図である。FIG. 3 is a cross-sectional view of the ceramic substrate of the second example of FIG. 3G, which is a cross-sectional view cut along the AA cutting line. 図３Ｇの第２例のセラミック基板の断面図であって、Ｂ－Ｂ切断線で切断した断面図である。FIG. 3 is a cross-sectional view of the ceramic substrate of the second example of FIG. 3G, which is a cross-sectional view cut along a BB cutting line. 本実施形態の第３例のセラミック基板の平面図であって、その板厚方向における高低度合（凹み具合）のプロファイルを付した状態の高低分布図である。It is a top view of the ceramic substrate of the 3rd example of this embodiment, and is the high-low distribution map in a state with the profile of the high-low degree degree (the degree of dent) in the plate thickness direction. 図３Ｊの第３例のセラミック基板の断面図であって、Ａ－Ａ切断線で切断した断面図である。It is sectional drawing of the ceramic substrate of the 3rd example of FIG. 3J, and is the sectional view cut by the AA cutting line. 図３Ｊの第３例のセラミック基板の断面図であって、Ｂ－Ｂ切断線で切断した断面図である。It is sectional drawing of the ceramic substrate of the 3rd example of FIG. 3J, and is the sectional view cut by the BB cutting line. 本実施形態の第４例のセラミック基板の平面図であって、その板厚方向における高低度合（凹み具合）のプロファイルを付した状態の高低分布図である。It is a top view of the ceramic substrate of the 4th example of this embodiment, and is the high-low distribution map in a state with the profile of the high-low degree degree (the degree of dent) in the plate thickness direction. 図３Ｍの第４例のセラミック基板の断面図であって、Ａ－Ａ切断線で切断した断面図である。FIG. 3 is a cross-sectional view of the ceramic substrate of the fourth example of FIG. 3M, which is a cross-sectional view cut along the AA cutting line. 図３Ｍの第４例のセラミック基板の断面図であって、Ｂ－Ｂ切断線で切断した断面図である。FIG. 3 is a cross-sectional view of the ceramic substrate of the fourth example of FIG. 3M, which is a cross-sectional view cut along a BB cutting line. 本実施形態の第５例のセラミック基板の平面図であって、その板厚方向における高低度合（凹み具合）のプロファイルを付した状態の高低分布図である。It is a top view of the ceramic substrate of the 5th example of this embodiment, and is the high-low distribution map in a state with the profile of the high-low degree degree (the degree of dent) in the plate thickness direction. 図３Ｐの第５例のセラミック基板の断面図であって、Ａ－Ａ切断線で切断した断面図である。It is sectional drawing of the ceramic substrate of 5th example of FIG. 3P, and is the sectional view cut by the AA cutting line. 図３Ｐの第５例のセラミック基板の断面図であって、Ｂ－Ｂ切断線で切断した断面図である。It is sectional drawing of the ceramic substrate of 5th example of FIG. 3P, and is the sectional view cut by the BB cutting line. 本実施形態の第６例のセラミック基板の平面図であって、その板厚方向における高低度合（凹み具合）のプロファイルを付した状態の高低分布図（７０μｍスパン）である。It is a top view of the ceramic substrate of the sixth example of this embodiment, and is the high-low distribution map (70 μm span) in a state where the profile of the high-low degree (dent degree) in the plate thickness direction is attached. 本実施形態の第６例のセラミック基板の平面図であって、その板厚方向における高低度合（凹み具合）のプロファイルを付した状態の高低分布図（１００μｍスパン）である。It is a top view of the ceramic substrate of the sixth example of this embodiment, and is the high-low distribution map (100 μm span) in a state where the profile of the high-low degree (dent degree) in the plate thickness direction is attached. 本実施形態の第６例のセラミック基板の平面図であって、その板厚方向における高低度合（凹み具合）のプロファイルを付した状態の高低分布図（２００μｍスパン）である。It is a top view of the ceramic substrate of the sixth example of this embodiment, and is the high-low distribution map (200 μm span) in a state where the profile of the high-low degree (dent degree) in the plate thickness direction is attached. 本実施形態の第６例のセラミック基板の平面図であって、その板厚方向における高低度合（凹み具合）のプロファイルを付した状態の高低分布図（３００μｍスパン）である。It is a top view of the ceramic substrate of the sixth example of this embodiment, and is the high-low distribution map (300 μm span) in a state where the profile of the high-low degree (dent degree) in the plate thickness direction is attached. 図３Ｓ～図３ＶにおけるＣ－Ｃ直線に沿ってレーザー３次元形状測定機に沿って測定した変位量分布を示すグラフである。3 is a graph showing a displacement amount distribution measured along a laser three-dimensional shape measuring machine along a CC straight line in FIGS. 3S to 3V. 本実施形態の複数の実装基板の製造方法に含まれる、外周部分切断工程を説明するための概略図である。It is the schematic for demonstrating the outer peripheral part cutting process included in the manufacturing method of the plurality of mounting substrates of this embodiment. 外周部分切断工程における、外周部分の切断幅と、反り量との関係を示すグラフである。It is a graph which shows the relationship between the cutting width of the outer peripheral part and the amount of warpage in the outer peripheral part cutting process. 本実施形態の複数の実装基板の製造方法に含まれる、スクライブライン形成工程を説明するための図である。It is a figure for demonstrating the scrib line forming process included in the manufacturing method of the plurality of mounting substrates of this embodiment. 本実施形態の複数の実装基板の製造方法に含まれる、金属層形成工程を説明するための図である。It is a figure for demonstrating the metal layer formation process included in the manufacturing method of the plurality of mounting substrates of this embodiment. 図６Ａのセラミック基板の断面図であって、６Ｂ－６Ｂ切断線で切断した横断面図である。FIG. 6A is a cross-sectional view of the ceramic substrate of FIG. 6A, which is a cross-sectional view cut along a 6B-6B cutting line. 本実施形態のセラミック基板の一部斜視図である。It is a partial perspective view of the ceramic substrate of this embodiment. 本実施形態の複数の実装基板の製造方法に含まれる、レジスト印刷工程を説明するための図である。It is a figure for demonstrating the resist printing process included in the manufacturing method of the plurality of mounting substrates of this embodiment. 本実施形態の複数の実装基板の製造方法に含まれる、エッチング工程を説明するための図である。It is a figure for demonstrating the etching process included in the manufacturing method of the plurality of mounting substrates of this embodiment. 本実施形態の複数の実装基板の製造方法に含まれる、分割工程を説明するための図である。It is a figure for demonstrating the division process included in the manufacturing method of the plurality of mounting substrates of this embodiment. 第１変形例の金属層形成工程を説明するための図である。It is a figure for demonstrating the metal layer formation process of the 1st modification. 第２変形例のセラミック基板の平面図であって、その板厚方向における高低度合（凹み具合）のプロファイルを付した状態の高低分布図である。It is a top view of the ceramic substrate of the 2nd modification, and is the height distribution figure in the state which the profile of the degree of height (the degree of dent) in the thickness direction is attached. 図１１Ａのセラミック基板の断面図であって、Ｘ０－Ｘ０切断線で切断した縦断面図、Ｘ１－Ｘ１切断線で切断した縦断面図及びＸ２－Ｘ２切断線で切断した縦断面図を、それぞれＸ方向に沿って並べた図である。11A is a cross-sectional view of the ceramic substrate, which is a vertical cross-sectional view cut along the X 0- X 0 cutting line, a vertical cross-sectional view cut along the X 1- X 1 cutting line, and cut along the X 2- X 2 cutting line. It is the figure which arranged the vertical sectional views along the X direction, respectively. 図１１Ａのセラミック基板の断面図であって、Ｙ０－Ｙ０切断線で切断した横断面図、Ｙ１－Ｙ１切断線で切断した横断面図及びＹ２－Ｙ２切断線で切断した横断面図を、それぞれＹ方向に沿って並べた図である。11A is a cross-sectional view of the ceramic substrate, which is a cross-sectional view cut along a Y 0- Y 0 cutting line, a cross-sectional view cut along a Y 1- Y 1 cutting line, and a cross section cut along a Y 2- Y 2 cutting line. It is the figure which arranged the cross-sectional view along the Y direction respectively.
≪概要≫
　以下、本実施形態について図面を参照しながら説明する。まず、本実施形態のセラミック基板４０（図３Ａ、図３Ｄ、図３Ｇ、図３Ｊ、図３Ｍ、図３Ｐ、図３Ｓ等参照）、マザーボード６０（複合基板の一例、図６Ａ及び図６Ｂ参照）、集合基板６０Ｂ（複合基板の他の一例、図８及び図９参照）及び回路基板６０Ｃ（図９参照）について説明する。
　次いで、本実施形態の複数の実装基板（図示省略）の製造方法について、図１等を参照しながら、図１に示す各工程順に説明する。
　次いで、本実施形態の効果について説明する。
　次いで、本実施形態の変形例について例えば図１０及び図１１Ａ～図１１Ｃを参照しながら説明する。
　なお、以下の説明で参照するすべての図面において、同様な構成要素には同様の符号を付し、適宜説明を省略する。 ≪Overview≫
Hereinafter, the present embodiment will be described with reference to the drawings. First, the ceramic substrate 40 of the present embodiment (see FIGS. 3A, 3D, 3G, 3J, 3M, 3P, 3S, etc.), the motherboard 60 (an example of a composite substrate, see 6A and 6B). The assembly board 60B (another example of the composite board, see FIGS. 8 and 9) and the circuit board 60C (see FIG. 9) will be described.
Next, a method of manufacturing a plurality of mounting substrates (not shown) of the present embodiment will be described in the order of each process shown in FIG. 1 with reference to FIG. 1 and the like.
Next, the effect of this embodiment will be described.
Next, a modified example of this embodiment will be described with reference to, for example, FIGS. 10 and 11A to 11C.
In all the drawings referred to in the following description, similar components are designated by the same reference numerals, and the description thereof will be omitted as appropriate.
≪本実施形態のセラミック基板≫
　以下、本実施形態のセラミック基板４０について図３Ｄ～図３Ｗ及び図６Ｂ～図６Ｃを参照しながら説明する。 << Ceramic substrate of this embodiment >>
Hereinafter, the ceramic substrate 40 of the present embodiment will be described with reference to FIGS. 3D to 3W and FIGS. 6B to 6C.
　本実施形態のセラミック基板４０は、以下の基本的な特徴を有する。セラミック基板４０は、平面視にて矩形状であって、セラミック基板４０の対角線の長さでセラミック基板４０の板厚方向における最大高低差を除した値は、１μｍ／ｍｍ以下であり、その端部には、セラミック基板４０の主面端部から面内方向に、板厚方向の一端から他端に亘る、複数本のクラックＭＣが形成されている。
　すなわち、本実施形態のセラミック基板４０は、ほぼ平坦又は完全に平坦であり、かつ、その端部にはセラミック基板４０の板厚方向の一端から他端に亘る、複数本のクラックＭＣが形成されている。
　なお、本実施形態における最大高低差については、第６例の説明の中で説明する。また、「セラミック基板４０の対角線の長さでセラミック基板４０の板厚方向における最大高低差を除した値」を「最大高低値」とする。 The ceramic substrate 40 of this embodiment has the following basic features. The ceramic substrate 40 has a rectangular shape in a plan view, and the value obtained by dividing the maximum height difference of the ceramic substrate 40 in the plate thickness direction by the diagonal length of the ceramic substrate 40 is 1 μm / mm or less, and the end thereof. A plurality of crack MCs are formed in the portion from one end to the other end in the plate thickness direction in the in-plane direction from the main surface end portion of the ceramic substrate 40.
That is, the ceramic substrate 40 of the present embodiment is substantially flat or completely flat, and a plurality of crack MCs are formed at the ends thereof from one end to the other end in the plate thickness direction of the ceramic substrate 40. ing.
The maximum height difference in this embodiment will be described in the description of the sixth example. Further, "the value obtained by dividing the diagonal length of the ceramic substrate 40 by the maximum height difference in the plate thickness direction of the ceramic substrate 40" is defined as the "maximum height value".
　また、本実施形態のセラミック基板４０は、上記の基本的な特徴の１つである、最大高低差の規定を満たす限りにおいて、その板厚方向に若干の凹凸を有してもよい。すなわち、その板厚方向の一方側又は他方側に向けて凸状となる、少なくとも１つの凸状部分が形成されてもよい。そして、このような凸状部分が形成された態様として、以下のようなものが挙げられる。
　例えば、本実施形態のセラミック基板４０のうちの一態様のセラミック基板４０は、その板厚方向の一方側又は他方側に向けて凸状となる、少なくとも１つの凸状部分が形成されている（図３Ｄ、図３Ｇ、図３Ｊ、図３Ｍ、図３Ｐ及び図３Ｓ参照）。
　また、例えば、本実施形態のセラミック基板４０のうちの一態様のセラミック基板４０は、少なくとも１つの凸状部分は、複数の凸状部分であり、前記複数の凸状部分は、それぞれ、セラミック基板４０における一対の対角線のうちの一方の対角線で区画される２つの領域に形成されている（図３Ｄ、図３Ｇ、図３Ｊ及び図３Ｍ参照）。
　また、例えば、本実施形態のセラミック基板４０のうちの一態様のセラミック基板４０は、少なくとも１つの凸状部分は、複数の凸状部分であり、前記複数の凸状部分は、それぞれ、セラミック基板４０における一対の対角線で区画される４つの領域に形成されている（図３Ｍ参照）。
　また、例えば、本実施形態のセラミック基板４０のうちの一態様のセラミック基板４０は、少なくとも１つの凸状部分は、複数の凸状部分であり、前記複数の凸状部分のうちの一部は、セラミック基板４０の板厚方向の一方側に向けて凸状となるように形成され、
　前記複数の凸状部分のうちの残りの一部は、前記板厚方向の他方側に向けて凸状となるように形成されている（図３Ｄ、図３Ｍ及び図３Ｐ参照）。 Further, the ceramic substrate 40 of the present embodiment may have some irregularities in the plate thickness direction as long as it satisfies the regulation of the maximum height difference, which is one of the above basic features. That is, at least one convex portion that becomes convex toward one side or the other side in the plate thickness direction may be formed. Then, as an embodiment in which such a convex portion is formed, the following can be mentioned.
For example, the ceramic substrate 40 of one aspect of the ceramic substrate 40 of the present embodiment is formed with at least one convex portion that is convex toward one side or the other side in the plate thickness direction (the ceramic substrate 40). 3D, 3G, 3J, 3M, 3P and 3S).
Further, for example, in the ceramic substrate 40 of one aspect of the ceramic substrate 40 of the present embodiment, at least one convex portion is a plurality of convex portions, and the plurality of convex portions are each a ceramic substrate. It is formed in two regions defined by one of the pair of diagonal lines in 40 (see FIGS. 3D, 3G, 3J and 3M).
Further, for example, in the ceramic substrate 40 of one aspect of the ceramic substrate 40 of the present embodiment, at least one convex portion is a plurality of convex portions, and the plurality of convex portions are each a ceramic substrate. It is formed in four regions defined by a pair of diagonal lines in 40 (see FIG. 3M).
Further, for example, in the ceramic substrate 40 of one aspect of the ceramic substrate 40 of the present embodiment, at least one convex portion is a plurality of convex portions, and a part of the plurality of convex portions is. , The ceramic substrate 40 is formed so as to be convex toward one side in the plate thickness direction.
The remaining part of the plurality of convex portions is formed so as to be convex toward the other side in the plate thickness direction (see FIGS. 3D, 3M, and 3P).
　次に、第１例～第６例により、図３Ｄ～図３Ｗを参照しながらセラミック基板４０の例を説明する。これらの例において、セラミック基板４０の表面４０Ａ１は、若干の凹凸を有しているものの略平坦面となっている。なお、これらの例に限らず、セラミック基板４０の表面４０Ａ１は凸状部分を有さない完全に平坦な面となっていてもよい。
　そして、以下に説明する第１例～第６例はそれぞれ本実施形態のセラミック基板４０の例示に過ぎず、上記の基本的な特徴を有するセラミック基板であれば、本実施形態のセラミック基板４０に含まれる。 Next, an example of the ceramic substrate 40 will be described with reference to FIGS. 3D to 3W according to the first to sixth examples. In these examples, the surface 40A1 of the ceramic substrate 40 is a substantially flat surface although it has some irregularities. Not limited to these examples, the surface 40A1 of the ceramic substrate 40 may be a completely flat surface having no convex portion.
The first to sixth examples described below are merely examples of the ceramic substrate 40 of the present embodiment, and any ceramic substrate having the above basic characteristics can be used as the ceramic substrate 40 of the present embodiment. included.
〔第１例のセラミック基板〕
　第１例のセラミック基板４０については、図３Ｄ～図３Ｆを参照しながら説明する。
　ここで、図３Ｄは、本実施形態の第１例のセラミック基板４０の平面図であって、その板厚方向（Ｚ方向）における高低度合（凹み具合）のプロファイルを付した状態の高低分布図である。図３Ｅは、第１例のセラミック基板４０の断面図であって、図３ＤのＡ－Ａ切断線で切断した第１例のセラミック基板４０の断面図である。図３Ｆは、第１例のセラミック基板４０の断面図であって、図３ＤのＢ－Ｂ切断線で切断した第１例のセラミック基板４０の断面図である。
　第１例のセラミック基板４０は、以下のような特徴を有する。 [Ceramic substrate of the first example]
The ceramic substrate 40 of the first example will be described with reference to FIGS. 3D to 3F.
Here, FIG. 3D is a plan view of the ceramic substrate 40 of the first example of the present embodiment, and is a height distribution diagram in a state where a profile of the degree of height (depression) in the thickness direction (Z direction) is attached. Is. FIG. 3E is a cross-sectional view of the ceramic substrate 40 of the first example, and is a cross-sectional view of the ceramic substrate 40 of the first example cut along the AA cutting line of FIG. 3D. FIG. 3F is a cross-sectional view of the ceramic substrate 40 of the first example, and is a cross-sectional view of the ceramic substrate 40 of the first example cut along the BB cutting line of FIG. 3D.
The ceramic substrate 40 of the first example has the following features.
　第１例のセラミック基板４０において、セラミック基板４０の端部には、セラミック基板４０の主面端部４０Ａ３から面内方向に、その板厚方向（Ｚ方向）の一端（表面４０Ａ１）から他端（裏面４０Ａ２）に亘る、複数本のマイクロクラックＭＣが形成されている（図６Ｂおよび図６Ｃ参照）。
　複数本のマイクロクラックＭＣは、端部の全周、すなわち外周面全域に亘って形成されている（以下、第１の特徴という。）。そして、複数本のマイクロクラックＭＣは、端部の周方向に定められた間隔ｐ１で並べられている。例えば、板厚３２０μｍのセラミック基板において、定められた間隔ｐ１は、一例として９０μｍ以上１１０μｍ以下である。また、主面側（表面４０Ａ１側）のマイクロクラックＭＣの長さＬ１１は一例として、１５μｍ以上２５μｍ以下である。 In the ceramic substrate 40 of the first example, the end portion of the ceramic substrate 40 is in-plane from the main surface end portion 40A3 of the ceramic substrate 40, and from one end (surface 40A1) to the other end in the plate thickness direction (Z direction). A plurality of microcracks MC are formed over (back surface 40A2) (see FIGS. 6B and 6C).
The plurality of microcracks MC are formed over the entire circumference of the end portion, that is, the entire outer peripheral surface (hereinafter, referred to as the first feature). The plurality of microcracks MC are arranged at intervals p1 defined in the circumferential direction of the end portion. For example, in a ceramic substrate having a plate thickness of 320 μm, the defined interval p1 is, for example, 90 μm or more and 110 μm or less. Further, the length L11 of the microcrack MC on the main surface side (surface 40A1 side) is, for example, 15 μm or more and 25 μm or less.
　また、第１例のセラミック基板４０において、平面視にて、その一対の対角線（図３Ｄの一対の破線）により形成される交差点Ｏとずれた位置に、その板厚方向（Ｚ方向）の一方側又は他方側に向けて凸状となる、少なくとも１つの凸状部分（第１例の場合は凸状部分ＣＸ１、ＣＸ２）が形成されており、最大高低値は、１μｍ／ｍｍ以下である（以下、第２の特徴という。）。
　第１例のセラミック基板４０及び後述する第２例～第５例のセラミック基板４０は、一例として、その長さが２０６ｍｍ、その幅が１４６ｍｍであるから、その対角線の長さは約２５２．５ｍｍである。また、凸状部分ＣＸ１、ＣＸ２の凸量（平坦な場合（図中の基準）に比べて凸状又は凹状になっている部分の量）を、それぞれΔＺ１、ΔＺ２とする。そして、凸量ΔＺ１、ΔＺ２は、それぞれ、一例として２５２μｍ以下である。すなわち、第１例の場合、最大高低差は２５２μｍ以下である。以上より、第１例のセラミック基板４０の最大高低値は、１μｍ／ｍｍ以下である。 Further, in the ceramic substrate 40 of the first example, one of the plate thickness directions (Z direction) is located at a position deviated from the intersection O formed by the pair of diagonal lines (a pair of broken lines in FIG. 3D) in a plan view. At least one convex portion (convex portions CX1 and CX2 in the case of the first example) is formed so as to be convex toward the side or the other side, and the maximum height value is 1 μm / mm or less (1 μm / mm or less). Hereinafter referred to as the second feature).
As an example, the ceramic substrate 40 of the first example and the ceramic substrates 40 of the second to fifth examples described later have a length of 206 mm and a width of 146 mm, so that the diagonal length thereof is about 252.5 mm. Is. Further, the convex amounts of the convex portions CX1 and CX2 (the amount of the convex or concave portions as compared with the flat case (reference in the figure)) are defined as ΔZ 1 and ΔZ 2 , respectively. The convex amounts ΔZ 1 and ΔZ 2 are 252 μm or less, respectively, as an example. That is, in the case of the first example, the maximum height difference is 252 μm or less. From the above, the maximum height value of the ceramic substrate 40 of the first example is 1 μm / mm or less.
　また、第１例のセラミック基板４０は、最大高低値が１μｍ／ｍｍ以下であることを前提として、複数の凸状部分（第１例では凸状部分ＣＸ１、ＣＸ２）は、それぞれ、セラミック基板４０における一対の対角線のうちの一方の対角線（第１例では両方の対角線）で区画される２つの領域に形成されている（以下、第３の特徴という）。 Further, in the ceramic substrate 40 of the first example, on the premise that the maximum height value is 1 μm / mm or less, the plurality of convex portions (convex portions CX1 and CX2 in the first example) are each of the ceramic substrate 40. It is formed in two regions divided by one diagonal line (both diagonal lines in the first example) of the pair of diagonal lines in (hereinafter referred to as a third feature).
　また、第１例のセラミック基板４０は、最大高低値が１μｍ／ｍｍ以下であることを前提として、複数の凸状部分（第１例では凸状部分ＣＸ１、ＣＸ２）のうちの一部（凸状部分ＣＸ１、ＣＸ２のうちの一方）は板厚方向（Ｚ方向）の一方側に向けて凸状となるように形成され、残りの一部（凸状部分ＣＸ１、ＣＸ２のうちの他方）は板厚方向の他方側に向けて凸状となるように形成されている（以下、第４の特徴という。）。 Further, the ceramic substrate 40 of the first example is a part (convex) of a plurality of convex portions (convex portions CX1 and CX2 in the first example) on the premise that the maximum height value is 1 μm / mm or less. (One of the convex portions CX1 and CX2) is formed so as to be convex toward one side in the plate thickness direction (Z direction), and the remaining part (the other of the convex portions CX1 and CX2) is formed. It is formed so as to be convex toward the other side in the plate thickness direction (hereinafter, referred to as a fourth feature).
　以上が、第１例のセラミック基板４０についての説明である。 The above is the description of the ceramic substrate 40 of the first example.
〔第２例のセラミック基板〕
　第２例のセラミック基板４０については、図３Ｇ～図３Ｉを参照しながら説明する。
　ここで、図３Ｇは、本実施形態の第２例のセラミック基板４０の平面図であって、その板厚方向（Ｚ方向）における高低度合（凹み具合）のプロファイルを付した状態の高低分布図である。図３Ｈは、第２例のセラミック基板４０の断面図であって、図３ＧのＡ－Ａ切断線で切断した第２例のセラミック基板４０の断面図である。図３Ｉは、第２例のセラミック基板４０の断面図であって、図３ＧのＢ－Ｂ切断線で切断した第２例のセラミック基板４０の断面図である。
　第２例のセラミック基板４０は、凸状部分ＣＸ１、ＣＸ２がそれぞれ板厚方向（Ｚ方向）の一方側（表面４０Ａ１側）に凸状となっている点で、第１例の場合（図３Ｄ参照）と異なる。また、第２例のセラミック基板４０は、第１例の場合の第１～第３の特徴を有する。 [Ceramic substrate of the second example]
The ceramic substrate 40 of the second example will be described with reference to FIGS. 3G to 3I.
Here, FIG. 3G is a plan view of the ceramic substrate 40 of the second example of the present embodiment, and is a height distribution diagram in a state where a profile of the degree of height (depression) in the thickness direction (Z direction) is attached. Is. FIG. 3H is a cross-sectional view of the ceramic substrate 40 of the second example, and is a cross-sectional view of the ceramic substrate 40 of the second example cut along the AA cutting line of FIG. 3G. FIG. 3I is a cross-sectional view of the ceramic substrate 40 of the second example, which is a cross-sectional view of the ceramic substrate 40 of the second example cut along the BB cutting line of FIG. 3G.
The ceramic substrate 40 of the second example is the case of the first example (FIG. 3D) in that the convex portions CX1 and CX2 are convex on one side (surface 40A1 side) in the plate thickness direction (Z direction), respectively. See) is different. Further, the ceramic substrate 40 of the second example has the first to third features of the case of the first example.
　以上が、第２例のセラミック基板４０についての説明である。 The above is the explanation of the ceramic substrate 40 of the second example.
〔第３例のセラミック基板〕
　第３例のセラミック基板４０については、図３Ｊ～図３Ｌを参照しながら説明する。
　ここで、図３Ｊは、本実施形態の第３例のセラミック基板４０の平面図であって、その板厚方向（Ｚ方向）における高低度合（凹み具合）のプロファイルを付した状態の高低分布図である。図３Ｋは、第３例のセラミック基板４０の断面図であって、図３ＪのＡ－Ａ切断線で切断した第３例のセラミック基板４０の断面図である。図３Ｌは、第３例のセラミック基板４０の断面図であって、図３ＪのＢ－Ｂ切断線で切断した第３例のセラミック基板４０の断面図である。
　第３例のセラミック基板４０は、凸状部分ＣＸ１、ＣＸ２がそれぞれ板厚方向（Ｚ方向）の他方側（裏面４０Ａ２側）に凸状となっている点で、第１例の場合（図３Ｄ参照）及び第２例の場合（図３Ｇ参照）と異なる。また、第３例のセラミック基板４０は、第１例の場合の第１～第３の特徴を有する。 [Ceramic substrate of the third example]
The ceramic substrate 40 of the third example will be described with reference to FIGS. 3J to 3L.
Here, FIG. 3J is a plan view of the ceramic substrate 40 of the third example of the present embodiment, and is a height distribution diagram in a state where a profile of the degree of height (depression) in the thickness direction (Z direction) is attached. Is. FIG. 3K is a cross-sectional view of the ceramic substrate 40 of the third example, and is a cross-sectional view of the ceramic substrate 40 of the third example cut along the AA cutting line of FIG. 3J. FIG. 3L is a cross-sectional view of the ceramic substrate 40 of the third example, and is a cross-sectional view of the ceramic substrate 40 of the third example cut along the BB cutting line of FIG. 3J.
The ceramic substrate 40 of the third example is the case of the first example (FIG. 3D) in that the convex portions CX1 and CX2 are convex on the other side (back surface 40A2 side) in the plate thickness direction (Z direction), respectively. (See) and the case of the second example (see FIG. 3G). Further, the ceramic substrate 40 of the third example has the first to third features of the case of the first example.
　以上が、第３例のセラミック基板４０についての説明である。 The above is the explanation of the ceramic substrate 40 of the third example.
〔第４例のセラミック基板〕
　第４例のセラミック基板４０については、図３Ｍ～図３Ｏを参照しながら説明する。
　ここで、図３Ｍは、本実施形態の第４例のセラミック基板４０の平面図であって、その板厚方向（Ｚ方向）における高低度合（凹み具合）のプロファイルを付した状態の高低分布図である。図３Ｎは、第４例のセラミック基板４０の断面図であって、図３ＭのＡ－Ａ切断線で切断した第４例のセラミック基板４０の断面図である。図３Ｎは、第４例のセラミック基板４０の断面図であって、図３ＭのＢ－Ｂ切断線で切断した第４例のセラミック基板４０の断面図である。
　第４例のセラミック基板４０は、最大高低値が１μｍ／ｍｍ以下であることを前提として、複数の凸状部分（凸状部分ＣＸ１、ＣＸ２、ＣＸ３、ＣＸ４）は、それぞれ、セラミック基板４０における一対の対角線で区画される４つの領域に形成されている（以下、第５の特徴という。）。そして、凸状部分ＣＸ３、ＣＸ４の凸量ΔＺ３、ΔＺ４は、一例として２５２μｍ以下である。また、第３例のセラミック基板４０は、第１例の場合の第１～第４の特徴を有する。 [Ceramic substrate of the 4th example]
The ceramic substrate 40 of the fourth example will be described with reference to FIGS. 3M to 3O.
Here, FIG. 3M is a plan view of the ceramic substrate 40 of the fourth example of the present embodiment, and is a height distribution diagram in a state where a profile of the degree of height (depression) in the thickness direction (Z direction) is attached. Is. FIG. 3N is a cross-sectional view of the ceramic substrate 40 of the fourth example, and is a cross-sectional view of the ceramic substrate 40 of the fourth example cut along the AA cutting line of FIG. 3M. FIG. 3N is a cross-sectional view of the ceramic substrate 40 of the fourth example, which is a cross-sectional view of the ceramic substrate 40 of the fourth example cut along the BB cutting line of FIG. 3M.
In the ceramic substrate 40 of the fourth example, on the premise that the maximum height value is 1 μm / mm or less, a plurality of convex portions (convex portions CX1, CX2, CX3, CX4) are each paired in the ceramic substrate 40. It is formed in four regions divided by the diagonal line of (hereinafter referred to as a fifth feature). The convex portions ΔZ 3 and ΔZ 4 of the convex portions CX3 and CX4 are, for example, 252 μm or less. Further, the ceramic substrate 40 of the third example has the first to fourth features of the case of the first example.
　以上が、第４例のセラミック基板４０についての説明である。 The above is the explanation of the ceramic substrate 40 of the fourth example.
〔第５例のセラミック基板〕
　第５例のセラミック基板４０については、図３Ｐ～図３Ｒを参照しながら説明する。
　ここで、図３Ｐは、本実施形態の第５例のセラミック基板４０の平面図であって、その板厚方向（Ｚ方向）における高低度合（凹み具合）のプロファイルを付した状態の高低分布図である。図３Ｑは、第５例のセラミック基板４０の断面図であって、図３ＰのＡ－Ａ切断線で切断した第５例のセラミック基板４０の断面図である。図３Ｒは、第５例のセラミック基板４０の断面図であって、図３ＰのＢ－Ｂ切断線で切断した第５例のセラミック基板４０の断面図である。
　第５例のセラミック基板４０において、凸状部分ＣＸ１、ＣＸ２が、それぞれセラミック基板４０における一対の対角線で区画される４つの領域のうちの１つの領域に形成されている。第５例のセラミック基板４０は、この点で、第１例の場合（図３Ｄ参照）と異なる。また、第５例のセラミック基板４０は、第１例の場合の第１及び第２の特徴を有する。 [Ceramic substrate of the fifth example]
The ceramic substrate 40 of the fifth example will be described with reference to FIGS. 3P to 3R.
Here, FIG. 3P is a plan view of the ceramic substrate 40 of the fifth example of the present embodiment, and is a height distribution diagram in a state where a profile of the degree of height (depression) in the thickness direction (Z direction) is attached. Is. FIG. 3Q is a cross-sectional view of the ceramic substrate 40 of the fifth example, and is a cross-sectional view of the ceramic substrate 40 of the fifth example cut along the AA cutting line of FIG. 3P. FIG. 3R is a cross-sectional view of the ceramic substrate 40 of the fifth example, and is a cross-sectional view of the ceramic substrate 40 of the fifth example cut along the BB cutting line of FIG. 3P.
In the ceramic substrate 40 of the fifth example, the convex portions CX1 and CX2 are formed in one of the four diagonally partitioned regions of the ceramic substrate 40, respectively. The ceramic substrate 40 of the fifth example differs from the case of the first example (see FIG. 3D) in this respect. Further, the ceramic substrate 40 of the fifth example has the first and second features of the case of the first example.
　以上が、第５例のセラミック基板４０についての説明である。 The above is the explanation of the ceramic substrate 40 of the fifth example.
〔第６例のセラミック基板〕
　第６例のセラミック基板４０については、図３Ｓ～図３Ｗを参照しながら説明する。
　ここで、図３Ｓ～図３Ｖは、それぞれ、本実施形態の第６例のセラミック基板４０の平面図であって、その板厚方向（Ｚ方向）における高低度合（凹み具合）のプロファイルを付した状態の高低分布図である。図３Ｓ～図３Ｖは、それぞれ後述する反り量の測定時の測定スパンが異なる（それぞれ、順に７０μｍ、１００μｍ、２００μｍ、３００μｍ）。
　図３Ｗは、図３Ｓ～図３ＶにおけるＣ－Ｃ直線に沿ってレーザー３次元形状測定機に沿って測定した変位量分布を示すグラフである。
　ここで、本実施形態では、セラミック基板４０の反り量を、以下のようにして測定した。すなわち、レーザー３次元形状測定機（キーエンス社製：ＬＫ－ＧＤ５００）により、セラミック基板４０へレーザー光を照射し、セラミック基板４０からの拡散反射された光を受光して変位量を算出し、セラミック基板４０の主面の反り量を測定した。この場合、測定ピッチは、１ｍｍ×１ｍｍとした。
　そして、本実施形態における「最大高低差」とは、上記レーザー３次元形状測定機により測定した変位から基準となる表面４０Ａ１（または裏面４０Ａ２）を算出して、その基準面からの変位量を算出したときの、最大の変位量をいう。 [Ceramic substrate of the sixth example]
The ceramic substrate 40 of the sixth example will be described with reference to FIGS. 3S to 3W.
Here, FIGS. 3S to 3V are plan views of the ceramic substrate 40 of the sixth example of the present embodiment, respectively, and are provided with profiles of high and low degrees (depressions) in the plate thickness direction (Z direction). It is a high-low distribution map of the state. 3S to 3V have different measurement spans when measuring the amount of warpage, which will be described later (70 μm, 100 μm, 200 μm, and 300 μm, respectively).
FIG. 3W is a graph showing the displacement amount distribution measured along the laser three-dimensional shape measuring machine along the CC straight line in FIGS. 3S to 3V.
Here, in the present embodiment, the amount of warpage of the ceramic substrate 40 was measured as follows. That is, a laser three-dimensional shape measuring machine (manufactured by Keyence Co., Ltd .: LK-GD500) irradiates the ceramic substrate 40 with laser light, receives the diffusely reflected light from the ceramic substrate 40, calculates the displacement amount, and calculates the amount of displacement of the ceramic. The amount of warpage of the main surface of the substrate 40 was measured. In this case, the measurement pitch was 1 mm × 1 mm.
Then, the "maximum height difference" in the present embodiment is calculated by calculating the reference front surface 40A1 (or back surface 40A2) from the displacement measured by the laser three-dimensional shape measuring machine, and calculating the displacement amount from the reference surface. The maximum amount of displacement when
　以上が、第６例のセラミック基板４０についての説明である。 The above is the explanation of the ceramic substrate 40 of the sixth example.
　なお、第１例～第６例のセラミック基板４０（図３Ｄ～図３Ｗ参照）は、前述のとおり、本実施形態のセラミック基板４０の例示であり、本実施形態のセラミック基板４０には、以下のような例も含まれる。
　例えば、第１例のセラミック基板４０の場合（図３Ｄ参照）、凸状部分ＣＸ１、ＣＸ２はセラミック基板４０における一対の対角線で区画される４つの領域のうちの交差点Ｏを挟んで長手方向（Ｙ方向）の両側に区画される２つの領域に形成されている。しかし、例えば凸状部分ＣＸ１、ＣＸ２は交差点Ｏを挟んで短手方向（Ｘ方向）の両側に区画される２つの領域に形成されていてもよい。
　また、例えば、第４例のセラミック基板４０の場合（図３Ｍ参照）、凸状部分ＣＸ２、ＣＸ３はセラミック基板４０の板厚方向（Ｚ方向）における裏面４０Ａ２側に凸状となっている（図３Ｎ、図３Ｏ参照）。しかし、例えば、凸状部分ＣＸ２、ＣＸ３のうちの一方又は両方は表面４０Ａ１側に凸状となっていてもよい。
　また、例えば、第１例のセラミック基板４０（図３Ｄ参照）に第５例のセラミック基板４０の凸状部分ＣＸ２（図３Ｐ参照）を組み合せたセラミック基板（図示省略）でもよい。
　また、例えば、第１例のセラミック基板４０（図３Ｄ参照）の凸状部分ＣＸ１、ＣＸ２のいずれか一方がないセラミック基板（図示省略）であってもよい。同様に、第５例のセラミック基板４０（図３Ｐ参照）の凸状部分ＣＸ１、ＣＸ２のいずれか一方がないセラミック基板（図示省略）であってもよい。 As described above, the ceramic substrates 40 of Examples 1 to 6 (see FIGS. 3D to 3W) are examples of the ceramic substrate 40 of the present embodiment, and the ceramic substrate 40 of the present embodiment includes the following. Examples such as are also included.
For example, in the case of the ceramic substrate 40 of the first example (see FIG. 3D), the convex portions CX1 and CX2 are located in the longitudinal direction (Y) with the intersection O of the four diagonal regions of the ceramic substrate 40 interposed therebetween. It is formed in two regions divided on both sides of the direction). However, for example, the convex portions CX1 and CX2 may be formed in two regions partitioned on both sides in the lateral direction (X direction) with the intersection O in between.
Further, for example, in the case of the ceramic substrate 40 of the fourth example (see FIG. 3M), the convex portions CX2 and CX3 are convex toward the back surface 40A2 in the plate thickness direction (Z direction) of the ceramic substrate 40 (FIG. 3M). 3N, see FIG. 3O). However, for example, one or both of the convex portions CX2 and CX3 may be convex toward the surface 40A1.
Further, for example, a ceramic substrate (not shown) in which the convex portion CX2 (see FIG. 3P) of the ceramic substrate 40 of the fifth example is combined with the ceramic substrate 40 of the first example (see FIG. 3D) may be used.
Further, for example, the ceramic substrate 40 (see FIG. 3D) of the first example may be a ceramic substrate (not shown) without any one of the convex portions CX1 and CX2. Similarly, the ceramic substrate 40 (see FIG. 3P) of the fifth example may be a ceramic substrate (not shown) without any one of the convex portions CX1 and CX2.
　以上が、本実施形態のセラミック基板４０についての説明である。 The above is the description of the ceramic substrate 40 of this embodiment.
≪マザーボード≫
　次に、本実施形態のマザーボード６０について図６Ａ及び図６Ｂを参照しながら説明する。
　本実施形態のマザーボード６０は、セラミック基板４０の表面４０Ａ１側に固定されている第１金属層５０Ａと、セラミック基板４０における裏面４０Ａ２側に固定されている第２金属層５０Ｂと、を備える。
　なお、図６Ａ及び図６Ｂのマザーボード６０では、セラミック基板４０に換えて後述するＳＬ付きセラミック基板４０Ａとなっている。ＳＬ付きセラミック基板４０Ａとは、後述するように、セラミック基板４０に一例として複数本のスクライブラインＳＬが形成されている基板である。
　以上が、本実施形態のマザーボード６０についての説明である。 ≪Motherboard≫
Next, the motherboard 60 of this embodiment will be described with reference to FIGS. 6A and 6B.
The motherboard 60 of the present embodiment includes a first metal layer 50A fixed to the front surface 40A1 side of the ceramic substrate 40, and a second metal layer 50B fixed to the back surface 40A2 side of the ceramic substrate 40.
In the motherboard 60 of FIGS. 6A and 6B, the ceramic substrate 40A with SL, which will be described later, is used instead of the ceramic substrate 40. The ceramic substrate 40A with SL is a substrate on which a plurality of scribe lines SL are formed as an example on the ceramic substrate 40, as will be described later.
The above is the description of the motherboard 60 of this embodiment.
≪回路基板≫
　次に、本実施形態の回路基板６０Ｃについて図９を参照しながら説明する。
　本実施形態の回路基板６０Ｃは、セラミック基板４０と、セラミック基板４０の表面４０Ａ１側に形成されている回路パターンＣＰと、セラミック基板４０における裏面４０Ａ２側に固定されている金属層（第２金属層５０Ｂ）と、を備える。
　以上が、本実施形態の回路基板６０Ｃについての説明である。 ≪Circuit board≫
Next, the circuit board 60C of this embodiment will be described with reference to FIG.
The circuit board 60C of the present embodiment includes a ceramic substrate 40, a circuit pattern CP formed on the front surface 40A1 side of the ceramic substrate 40, and a metal layer (second metal layer) fixed to the back surface 40A2 side of the ceramic substrate 40. 50B) and.
The above is the description of the circuit board 60C of this embodiment.
≪本実施形態の複数の実装基板の製造方法≫
　次に、本実施形態の複数の実装基板の製造方法Ｓ１００（以下、本実施形態の製造方法Ｓ１００という。）について、図１等を参照しながら説明する。
　本実施形態の製造方法Ｓ１００は、図１に示すように、グリーンシート形成工程Ｓ１と、焼結工程Ｓ２と、外周部分切断工程Ｓ３と、スクライブライン形成工程Ｓ４（以下、ＳＬ形成工程Ｓ４という。）と、金属層形成工程Ｓ５と、レジスト印刷工程Ｓ６と、エッチング工程Ｓ７と、表面処理工程Ｓ８と、分割工程Ｓ９と、実装工程Ｓ１０とを含む。そして、本実施形態の製造方法Ｓ１００は、これらの各工程の記載順で行なわれる。 << Manufacturing method of a plurality of mounting boards of this embodiment >>
Next, the manufacturing method S100 of the plurality of mounting substrates of the present embodiment (hereinafter, referred to as the manufacturing method S100 of the present embodiment) will be described with reference to FIG. 1 and the like.
As shown in FIG. 1, the manufacturing method S100 of the present embodiment is referred to as a green sheet forming step S1, a sintering step S2, an outer peripheral partial cutting step S3, and a scribing line forming step S4 (hereinafter referred to as SL forming step S4). ), A metal layer forming step S5, a resist printing step S6, an etching step S7, a surface treatment step S8, a dividing step S9, and a mounting step S10. Then, the manufacturing method S100 of the present embodiment is performed in the order described in each of these steps.
　なお、本実施形態の製造方法Ｓ１００における各工程の終了時と、その時点での製造物との関係は、以下のとおりである。

＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝
　　終了時の各工程　　　　　その時点での製造物
＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝
　　焼結工程Ｓ２　　　　　　セラミック基板４０（図３Ｄ参照）
　　ＳＬ形成工程Ｓ４　　　　ＳＬ付きセラミック基板４０Ａ（図５参照）
　　金属層形成工程Ｓ５　　　マザーボード６０（図６Ａ及び図６Ｂ参照）
　　エッチング工程Ｓ７　　　集合基板６０Ｂ（図８参照）
　　分割工程Ｓ９　　　　　　複数の回路基板６０Ｃ（図９参照）
　　実装工程Ｓ１０　　　　　複数の実装基板
＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝
The relationship between the end of each step in the manufacturing method S100 of the present embodiment and the product at that time is as follows.

========================================
Each process at the end Product at that time ======================================= = =
Sintering step S2 Ceramic substrate 40 (see FIG. 3D)
SL forming step S4 Ceramic substrate with SL 40A (see FIG. 5)
Metal layer forming step S5 Motherboard 60 (see FIGS. 6A and 6B)
Etching step S7 Assembly substrate 60B (see FIG. 8)
Division step S9 Multiple circuit boards 60C (see FIG. 9)
Mounting process S10 Multiple mounting boards ========================================
　また、本実施形態の製造方法Ｓ１００の各工程の説明には、以下の各発明の説明が含まれる。
（セラミック基板の製造方法に関する発明）
　本実施形態のセラミック基板４０の製造方法は、セラミック粉末を含む帯状グリーンシート２０を切断して枚葉グリーンシート３０を得る帯状グリーンシート２０の切断工程と、焼成室内に枚葉グリーンシート３０を配置して、前記焼成室内の温度が少なくとも１６００℃以上になるまで前記焼成室内を加熱した後に前記焼成室内を冷却し、枚葉グリーンシート３０を焼結させてセラミック基板４０を得る焼結工程と、前記焼結工程の後に冷却したセラミック基板４０の全周縁側の部分を切断するセラミック基板４０の切断工程と、を含む（図１、図４Ａ参照）。
　さらに、本実施形態のセラミック基板４０の製造方法は、前記焼結工程において、前記焼成室内の冷却時に前記焼成室内の温度が６５０℃以下の温度になった場合に前記焼成室内の温度を急冷する（図１、図２Ｂ、図２Ｃ、図３Ｂ等参照）。
（マザーボードの製造方法に関する発明）
　本実施形態のマザーボード６０の製造方法は、前述のセラミック基板の製造方法と、セラミック基板４０の表面４０Ａ１側に第１金属層５０Ａを固定し、裏面４０Ａ２側に第２金属層５０Ｂを固定する固定工程と、を含む（図６Ａ参照）。
（回路基板の製造方法に関する発明）
　本実施形態の回路基板６０Ｃの製造方法は、前述のマザーボード６０の製造方法と、第１金属層５０Ａ及び第２金属層５０Ｂのいずれか一方（本実施形態の場合は一例として第１金属層５０Ａ）に、少なくとも１つの回路パターンＣＰを形成するパターン形成工程と、を含む（図７、図８等参照）。
（複数の回路基板の製造方法に関する発明）
　本実施形態の複数の回路基板６０Ｃの製造方法は、前述のマザーボード６０の製造方法と、第１金属層５０Ａ及び第２金属層５０Ｂのいずれか一方（本実施形態の場合は一例として第１金属層５０Ａ）に、複数の回路パターンＣＰを形成するパターン形成工程と、複数の回路パターンＣＰが形成されたマザーボード６０を、それぞれが１つの回路パターンＣＰを備える複数の回路基板６０Ｃに分割する分割工程と、を含む（図７～図９等参照）。
　以下、各工程について説明する。 In addition, the description of each step of the manufacturing method S100 of the present embodiment includes the following description of each invention.
(Invention relating to a method for manufacturing a ceramic substrate)
The method for manufacturing the ceramic substrate 40 of the present embodiment includes a step of cutting the band-shaped green sheet 20 for obtaining the single-wafer green sheet 30 by cutting the band-shaped green sheet 20 containing the ceramic powder, and arranging the single-leaf green sheet 30 in the firing chamber. Then, after heating the firing chamber until the temperature in the firing chamber reaches at least 1600 ° C. or higher, the firing chamber is cooled, and the single-wafer green sheet 30 is sintered to obtain a ceramic substrate 40. A step of cutting the ceramic substrate 40, which cuts a portion on the entire peripheral edge side of the cooled ceramic substrate 40 after the sintering step, is included (see FIGS. 1 and 4A).
Further, in the method for manufacturing the ceramic substrate 40 of the present embodiment, in the sintering step, when the temperature in the firing chamber becomes 650 ° C. or lower when the firing chamber is cooled, the temperature in the firing chamber is rapidly cooled. (See FIGS. 1, 2B, 2C, 3B, etc.).
(Invention relating to a manufacturing method of a motherboard)
The manufacturing method of the motherboard 60 of the present embodiment is the above-mentioned manufacturing method of the ceramic substrate and the fixing of fixing the first metal layer 50A on the front surface 40A1 side of the ceramic substrate 40 and fixing the second metal layer 50B on the back surface 40A2 side. Includes steps (see FIG. 6A).
(Invention relating to a method for manufacturing a circuit board)
The method for manufacturing the circuit board 60C of the present embodiment is one of the above-mentioned manufacturing method of the motherboard 60 and either the first metal layer 50A or the second metal layer 50B (in the case of the present embodiment, the first metal layer 50A is an example. ) Includes a pattern forming step of forming at least one circuit pattern CP (see FIGS. 7, 8 and the like).
(Invention relating to a method for manufacturing a plurality of circuit boards)
The method for manufacturing the plurality of circuit boards 60C of the present embodiment is one of the above-mentioned method for manufacturing the motherboard 60 and either the first metal layer 50A or the second metal layer 50B (in the case of the present embodiment, the first metal is an example. A pattern forming step of forming a plurality of circuit pattern CPs on the layer 50A) and a dividing step of dividing the motherboard 60 on which the plurality of circuit pattern CPs are formed into a plurality of circuit boards 60C each having one circuit pattern CP. And (see FIGS. 7 to 9, etc.).
Hereinafter, each step will be described.
＜グリーンシート形成工程及び焼結工程＞
　本実施形態における、グリーンシート形成工程Ｓ１及び焼結工程Ｓ２を組み合せてこれらの記載順で行う工程は、セラミック基板４０の製造方法に相当する。
　以下、本実施形態のセラミック基板４０の製造方法について、図２Ａ～図２Ｄ、図３Ａ～図３Ｒ並びに図４Ａ及び図４Ｂを参照しながら説明する。 <Green sheet forming process and sintering process>
The step of combining the green sheet forming step S1 and the sintering step S2 in the present embodiment in the order described corresponds to the method for manufacturing the ceramic substrate 40.
Hereinafter, the method for manufacturing the ceramic substrate 40 of the present embodiment will be described with reference to FIGS. 2A to 2D, FIGS. 3A to 3R, and FIGS. 4A and 4B.
　ここで、セラミック基板４０は、一例として、電気自動車、鉄道車両その他産業機器に搭載されるパワーモジュール用の回路基板又は実装基板に用いられる。セラミック基板４０は、一例として、後述する枚葉グリーンシート３０（図２Ｃ参照）を積層した状態で焼結して得られる（図３Ａ参照）。また、枚葉グリーンシート３０は、帯状グリーンシート２０（図２Ｂ及び図２Ｃ参照）を切断して得られる。すなわち、セラミック基板４０と枚葉グリーンシート３０とは、完成品と中間品（完成品になる前の工程で製造された物）との関係、又は、第１中間品と第２中間品（第１中間品になる前の工程で製造された物）との関係を有する。そのため、本実施形態の枚葉グリーンシート３０は、本実施形態のセラミック基板４０の製造方法の中間段階までの工程で製造される。
　なお、本実施形態のセラミック基板４０は、一例として、矩形の板である（図３Ｄ、図３Ｇ、図３Ｊ、図３Ｍ、図３Ｐ、図５等参照）。 Here, the ceramic substrate 40 is used, for example, as a circuit board or a mounting substrate for a power module mounted on an electric vehicle, a railroad vehicle, or other industrial equipment. As an example, the ceramic substrate 40 is obtained by sintering a single-wafer green sheet 30 (see FIG. 2C) described later in a laminated state (see FIG. 3A). The single-wafer green sheet 30 is obtained by cutting the strip-shaped green sheet 20 (see FIGS. 2B and 2C). That is, the ceramic substrate 40 and the single-wafer green sheet 30 have a relationship between a finished product and an intermediate product (a product manufactured in a process before becoming a finished product), or a first intermediate product and a second intermediate product (second intermediate product). (1) It has a relationship with the product (manufactured in the process before becoming an intermediate product). Therefore, the single-wafer green sheet 30 of the present embodiment is manufactured by the steps up to the intermediate stage of the manufacturing method of the ceramic substrate 40 of the present embodiment.
The ceramic substrate 40 of the present embodiment is, for example, a rectangular plate (see FIGS. 3D, 3G, 3J, 3M, 3P, 5 and the like).
＜グリーンシート形成工程＞
　以下、グリーンシート形成工程Ｓ１について、図２Ａ、図２Ｂ、図２Ｃ及び図２Ｄを参照しながら説明する。本実施形態のグリーンシート形成工程Ｓ１は、スラリー作製工程Ｓ１１と、成形工程Ｓ１２と、切断工程Ｓ１３と、堆積工程Ｓ１４と、脱脂工程Ｓ１５とを含み、これらの記載順で行われる（図１及び図２Ａ参照）。 <Green sheet forming process>
Hereinafter, the green sheet forming step S1 will be described with reference to FIGS. 2A, 2B, 2C and 2D. The green sheet forming step S1 of the present embodiment includes a slurry manufacturing step S11, a molding step S12, a cutting step S13, a deposition step S14, and a degreasing step S15, and is performed in the order described in these steps (FIGS. 1 and S1). See FIG. 2A).
〔スラリー作製工程〕
　スラリー作製工程Ｓ１１を説明する。本工程は、後述する原料粉末と有機溶剤とを混合して、スラリー１０を作成する。本工程で作製されたスラリー１０（図２Ｂ参照）は、次の工程（成形工程Ｓ１２）で帯状グリーンシート２０に成形される。 [Slurry preparation process]
The slurry preparation step S11 will be described. In this step, the raw material powder described later and an organic solvent are mixed to prepare a slurry 10. The slurry 10 produced in this step (see FIG. 2B) is molded into a band-shaped green sheet 20 in the next step (molding step S12).
　スラリー１０の原料粉末は、後述する主成分と焼結助剤とを含有する粉末である。主成分は一例として８０重量％～９８．３質量％の窒化珪素（Ｓｉ３Ｎ４）であり、焼結助剤は一例として１重量％～１０質量％（酸化物換算）の少なくとも１種の希土類元素及び０．７重量％～１０質量％（酸化物換算）のマグネシウム（Ｍｇ）である。窒化珪素の粉末のα化率は、セラミック基板４０の密度、曲げ強度及び熱伝導率を考慮すると、好ましくは２０％～１００％である。
　ここで、本明細書で使用する「～」の意味について補足すると、例えば「２０％～１００％」は「２０％以上１００％以下」を意味する。そして、本明細書で使用する「～」は、「『～』の前の記載部分以上『～』の後の記載部分以下」を意味する。 The raw material powder of the slurry 10 is a powder containing a main component and a sintering aid, which will be described later. Main component is 80 wt% to 98.3 wt% of silicon nitride as an example (Si 3 N 4), sintering aid of at least one 1 wt% to 10 wt% as an example (as oxide) It is a rare earth element and 0.7% by mass to 10% by mass (oxide equivalent) of magnesium (Mg). The pregelatinization rate of the silicon nitride powder is preferably 20% to 100% in consideration of the density, bending strength and thermal conductivity of the ceramic substrate 40.
Here, supplementing the meaning of "-" used in the present specification, for example, "20% to 100%" means "20% or more and 100% or less". And, "-" used in this specification means "more than the description part before"- "and less than the description part after"- "".
　窒化珪素（Ｓｉ３Ｎ４）の原料粉末における割合を一例として８０重量％～９８．３質量％とする理由は、得られるセラミック基板４０の曲げ強度及び熱伝導率が低すぎないこと、焼結助剤の不足によるセラミック基板４０の緻密性を担保すること等による。 The reason for the 80 wt% to 98.3 wt% as an example ratio in the raw material powder of silicon nitride (Si 3 N 4), it flexural strength and thermal conductivity of the ceramic substrate 40 obtained is not too low, sintering This is due to ensuring the denseness of the ceramic substrate 40 due to the shortage of auxiliary agents.
　以下、説明の簡略化のために、窒化珪素の原料粉末をＳｉ３Ｎ４粉末（別名は窒化珪素粉末、セラミック粉末の一例）、Ｍｇの原料粉末をＭｇＯ粉末、希土類元素原料の粉末をＹ２Ｏ３粉末と表記する。ただし、窒化珪素の原料粉末及び焼結助剤の原料粉末は、それぞれ、Ｓｉ３Ｎ４粉末並びにＭｇＯ粉末及びＹ２Ｏ３粉末でなくてもよい。 Hereinafter, for the sake of simplification of the description, the raw material powder of silicon nitride is Si 3 N 4 powder (also known as silicon nitride powder or an example of ceramic powder), the raw material powder of Mg is MgO powder, and the powder of rare earth element raw material is Y 2 O 3 powdered denoted. However, the raw material powder of silicon nitride and the raw material powder of the sintering aid do not have to be Si 3 N 4 powder, Mg O powder and Y 2 O 3 powder, respectively.
　そして、前述のように配合されたＳｉ３Ｎ４粉末、ＭｇＯ粉末及びＹ２Ｏ３粉末と、可塑剤、有機バインダー及び有機溶剤とを混合して、スラリー１０が作製される。そのため、本工程で作製されるスラリー１０は、セラミック粉末を含む。 Then, the Si 3 N 4 powder, the Mg O powder and the Y 2 O 3 powder blended as described above are mixed with a plasticizer, an organic binder and an organic solvent to prepare a slurry 10. Therefore, the slurry 10 produced in this step contains ceramic powder.
　以上が、スラリー作製工程Ｓ１１についての説明である。 The above is the description of the slurry preparation step S11.
〔成形工程〕
　次に、成形工程Ｓ１２について説明する。本工程は、図２Ｂに示すように、スラリー１０から帯状グリーンシート２０を製造する。 [Molding process]
Next, the molding step S12 will be described. In this step, as shown in FIG. 2B, a strip-shaped green sheet 20 is produced from the slurry 10.
　本工程は、一例として、図２Ｂに示すドクターブレード成形装置１００を用いて行われる。ここで、ドクターブレード成形装置１００は、ベルト搬送機構１１０と、成形ユニット１２０と、加熱ユニット１３０とを備える。ベルト搬送機構１１０は、上流側のローラ１１２Ａ、下流側のローラ１１２Ｂ及びベルト１１４を有し、下流側のローラ１１２を駆動させて、ベルト１１４を上流側のローラ１１２から下流側のローラ１１２に（Ｘ方向に沿って）移動させる。成形ユニット１２０は、ベルト１１４の上側（ベルト１１４よりもＺ方向側）に配置され、ベルト１１４に対向している。成形ユニット１２０は、スラリー１０を収容する収容部１２２とドクターブレード１２４とを有する。 This step is performed using the doctor blade forming apparatus 100 shown in FIG. 2B as an example. Here, the doctor blade forming apparatus 100 includes a belt conveying mechanism 110, a forming unit 120, and a heating unit 130. The belt transport mechanism 110 has a roller 112A on the upstream side, a roller 112B on the downstream side, and a belt 114, and drives the roller 112 on the downstream side to move the belt 114 from the roller 112 on the upstream side to the roller 112 on the downstream side. Move (along the X direction). The molding unit 120 is arranged on the upper side of the belt 114 (on the Z direction side of the belt 114) and faces the belt 114. The molding unit 120 has an accommodating portion 122 accommodating the slurry 10 and a doctor blade 124.
　そして、成形ユニット１２０は、図２Ｂに示すように、自重及び移動するベルト１１４との付着力により収容部１２２から持ち出されるスラリー１０を、ドクターブレード１２４により規制して定められた膜厚を有するシート状にする。加熱ユニット１３０は、定められた膜厚にされたベルト１１４上のスラリー１０に温風ＷＣを吹き付けてスラリー１０をシートにする（有機溶剤を気化させる）。その結果、成形工程Ｓ１２では、スラリー１０から定められた幅（図中Ｙ方向が幅方向に相当）の帯状グリーンシート２０が作製される。すなわち、成形工程Ｓ１２では、スラリー１０をドクターブレード成形により帯状にして、一例としてＳｉ３Ｎ４（セラミック）を含んで構成される帯状グリーンシート２０を得る。 Then, as shown in FIG. 2B, the molding unit 120 is a sheet having a film thickness determined by regulating the slurry 10 taken out from the accommodating portion 122 by its own weight and the adhesive force with the moving belt 114 by the doctor blade 124. Make it into a shape. The heating unit 130 blows warm air WC onto the slurry 10 on the belt 114 having a predetermined film thickness to form the slurry 10 into a sheet (vaporizes the organic solvent). As a result, in the molding step S12, a band-shaped green sheet 20 having a width defined from the slurry 10 (the Y direction in the drawing corresponds to the width direction) is produced. That is, in the molding step S12, the slurry 10 is formed into a band by doctor blade molding to obtain a band-shaped green sheet 20 containing Si 3 N 4 (ceramic) as an example.
　なお、本工程は、一例として、スラリー作製工程Ｓ１１で作製されたスラリー１０の脱泡をし、かつ、スラリー１０を増粘させた後に行われる。また、本工程で作製される帯状グリーンシート２０の膜厚は、最終的に製造されるセラミック基板４０の膜厚を考慮して設定される。これに伴い、スラリー１０を定められた膜厚に規制するためのドクターブレード１２４の規制条件（ベルト１１４との離間距離等）も最終的に製造されるセラミック基板４０の膜厚を考慮して設定される。 As an example, this step is performed after defoaming the slurry 10 produced in the slurry production step S11 and thickening the slurry 10. Further, the film thickness of the band-shaped green sheet 20 produced in this step is set in consideration of the film thickness of the ceramic substrate 40 finally produced. Along with this, the regulation conditions (distance from the belt 114, etc.) of the doctor blade 124 for regulating the slurry 10 to a predetermined film thickness are also set in consideration of the film thickness of the ceramic substrate 40 to be finally manufactured. Will be done.
　以上が、成形工程Ｓ１２についての説明である。 The above is the explanation of the molding process S12.
〔切断工程〕
　次に、帯状グリーンシート２０の切断工程Ｓ１３について説明する。本工程は、図２Ｃに示すように、帯状グリーンシート２０を切断して枚葉グリーンシート３０を製造する。 [Cutting process]
Next, the cutting step S13 of the strip-shaped green sheet 20 will be described. In this step, as shown in FIG. 2C, the strip-shaped green sheet 20 is cut to produce a single-wafer green sheet 30.
　本工程は、一例として、図２Ｃに示す切断装置２００を用いて行われる。ここで、切断装置２００は、シート搬送機構２１０と、切断部２２０とを備える。
　シート搬送機構２１０は、支持部２１２と、第１搬送部２１４と、第２搬送部２１６とを有する。支持部２１２は、成形工程Ｓ１２で作製された帯状グリーンシート２０が外周面に巻き付けられているローラ１１２Ｂ（図２Ｂ及び図２Ｃ参照）を回転可能に支持する。第１搬送部２１４は、支持部２１２から搬送された帯状グリーンシート２０の姿勢を整えて帯状グリーンシート２０をＸ方向に沿って（帯状グリーンシート２０の長手方向に沿って）切断部２２０に搬送する。第２搬送部２１６は、切断部２２０で帯状グリーンシート２０が切断されて作製された枚葉グリーンシート３０を更に下流に（Ｘ方向に）搬送する。
　また、切断部２２０は、筐体２２２と、照射部２２４と、移動機構２２６とを有している。照射部２２４は、一例として、レーザー光ＬＢを照射する。移動機構２２６は、照射部２２４を帯状グリーンシート２０の短手方向（図中Ｙ方向）の一端から他端に亘って走査させる。照射部２２４及び移動機構２２６は、筐体２２２に取り付けられている。 This step is performed by using the cutting device 200 shown in FIG. 2C as an example. Here, the cutting device 200 includes a sheet transport mechanism 210 and a cutting portion 220.
The sheet transport mechanism 210 has a support portion 212, a first transport portion 214, and a second transport portion 216. The support portion 212 rotatably supports the roller 112B (see FIGS. 2B and 2C) in which the strip-shaped green sheet 20 produced in the molding step S12 is wound around the outer peripheral surface. The first transport portion 214 arranges the posture of the strip-shaped green sheet 20 transported from the support portion 212 and conveys the strip-shaped green sheet 20 to the cutting portion 220 along the X direction (along the longitudinal direction of the strip-shaped green sheet 20). To do. The second transport section 216 transports the single-wafer green sheet 30 produced by cutting the strip-shaped green sheet 20 at the cutting section 220 further downstream (in the X direction).
Further, the cutting portion 220 has a housing 222, an irradiation portion 224, and a moving mechanism 226. The irradiation unit 224 irradiates the laser beam LB as an example. The moving mechanism 226 scans the irradiation unit 224 from one end to the other end of the strip-shaped green sheet 20 in the lateral direction (Y direction in the drawing). The irradiation unit 224 and the moving mechanism 226 are attached to the housing 222.
　そして、本実施形態の切断装置２００は、シート搬送機構２１０により帯状グリーンシート２０を枚葉グリーンシート３０の長さ分搬送して帯状グリーンシート２０を停止させ、切断部２２０により帯状グリーンシート２０を切断する。この場合、切断部２２０は、移動機構２２６により照射部２２４をＹ方向に沿って帯状グリーンシート２０の短手方向の一端側から他端側に亘って移動させながら、照射部２２４にレーザー光ＬＢを照射させる（図２D参照）。また、移動機構２２６により走査される照射部２２４は、レーザー光ＬＢを間欠的に照射する。ここで、「間欠的に」とは、一定期間照射することと一定期間照射しないこととを繰り返すことを意味する。そのため、移動機構２２６は、照射部２２４が移動と停止とを繰り返すようにして、照射部２２４を走査させる（図２Ｄ参照）。
　以上のようにして、本工程では、帯状グリーンシート２０にレーザー光ＬＢを照射することで帯状グリーンシート２０を切断して枚葉グリーンシート３０を得る。なお、レーザー光ＬＢは、帯状グリーンシート２０を切断することができれば、炭酸ガスレーザー光、赤外線レーザー光、紫外線レーザー光その他のレーザー光でもよい。また、本工程の説明では、一例として図２Ｃに示す切断装置２００を用いて帯状グリーンシート２０を切断して枚葉グリーンシート３０を製造するとしたが、帯状グリーンシート２０から枚葉グリーンシート３０を製造することができれば、他の方法を用いてもよい。例えば、プレス加工装置（図示省略）を用いて、プレスにより帯状グリーンシート２０を打ち抜いて枚葉グリーンシート３０を製造してもよい。 Then, in the cutting device 200 of the present embodiment, the strip-shaped green sheet 20 is conveyed by the sheet conveying mechanism 210 for the length of the single-wafer green sheet 30 to stop the strip-shaped green sheet 20, and the strip-shaped green sheet 20 is stopped by the cutting portion 220. Disconnect. In this case, the cutting portion 220 moves the irradiation portion 224 along the Y direction from one end side to the other end side in the lateral direction of the band-shaped green sheet 20 by the moving mechanism 226, while the laser light LB is transferred to the irradiation portion 224. (See Fig. 2D). Further, the irradiation unit 224 scanned by the moving mechanism 226 intermittently irradiates the laser beam LB. Here, "intermittently" means repeating irradiation for a certain period of time and non-irradiation for a certain period of time. Therefore, the moving mechanism 226 scans the irradiation unit 224 by causing the irradiation unit 224 to repeatedly move and stop (see FIG. 2D).
As described above, in this step, the band-shaped green sheet 20 is irradiated with the laser beam LB to cut the band-shaped green sheet 20 to obtain the single-wafer green sheet 30. The laser light LB may be a carbon dioxide gas laser light, an infrared laser light, an ultraviolet laser light, or other laser light as long as the band-shaped green sheet 20 can be cut. Further, in the description of this step, as an example, the strip-shaped green sheet 20 is cut by using the cutting device 200 shown in FIG. 2C to manufacture the single-wafer green sheet 30, but the single-leaf green sheet 30 is formed from the strip-shaped green sheet 20. Other methods may be used as long as they can be produced. For example, a strip-shaped green sheet 20 may be punched out by a press using a press working apparatus (not shown) to produce a single-wafer green sheet 30.
　以上が、帯状グリーンシート２０の切断工程Ｓ１３についての説明である。 The above is the explanation of the cutting step S13 of the strip-shaped green sheet 20.
〔堆積工程〕
　次に、堆積工程Ｓ１４について説明する。本工程は、図３Ａに示すように、複数の枚葉グリーンシート３０をその厚み方向に重ねる。本工程は、後の工程（焼結工程Ｓ２）で効率的に枚葉グリーンシート３０を焼結させるために行われる。 [Sedimentation process]
Next, the deposition step S14 will be described. In this step, as shown in FIG. 3A, a plurality of single-wafer green sheets 30 are stacked in the thickness direction thereof. This step is performed in order to efficiently sinter the single-wafer green sheet 30 in a later step (sintering step S2).
　本工程では、図３Ａに示すように、複数の枚葉グリーンシート３０を、後述する非反応性粉末層（図示省略）を介して堆積する。ここで、枚葉グリーンシート３０を重なる枚数が少ないと、後の焼結工程Ｓ２において焼結炉（図示省略）で一度に処理できる枚数が少なくなる（生産効率が低くなる）。これに対して、枚葉グリーンシート３０を重ねる枚数が多いと、次の工程（脱脂工程Ｓ１５）において枚葉グリーンシート３０に含まれるバインダーが分解し難くなる。以上の理由により、本工程において枚葉グリーンシート３０を重ねる枚数は８枚～１００枚、好ましくは３０枚～７０枚である。 In this step, as shown in FIG. 3A, a plurality of single-wafer green sheets 30 are deposited via a non-reactive powder layer (not shown) described later. Here, if the number of sheets of the sheet-fed green sheets 30 that overlap each other is small, the number of sheets that can be processed at one time in the sintering furnace (not shown) in the subsequent sintering step S2 is small (the production efficiency is low). On the other hand, if the number of sheets of the sheet-fed green sheet 30 stacked is large, the binder contained in the sheet-fed green sheet 30 is less likely to be decomposed in the next step (defatting step S15). For the above reasons, the number of sheet-fed green sheets 30 to be stacked in this step is 8 to 100, preferably 30 to 70.
　また、本実施形態の非反応性粉末層は、一例として、膜厚が約１μｍ～２０μｍの窒化硼素粉末層（ＢＮ粉末層）である。ＢＮ粉末層は、次の工程（焼結工程Ｓ２）後にセラミック基板４０を容易に分離させる機能を有する。ＢＮ粉末層は、ＢＮ粉末のスラリーとして、各枚葉グリーンシート３０の一面に、例えばスプレー、ブラシ塗布、ロールコーター、スクリーン印刷等によって塗布される。なお、ＢＮ粉末は８５％以上の純度で、好ましくは平均粒径が１μｍ～２０μｍである。 Further, the non-reactive powder layer of the present embodiment is, for example, a boron nitride powder layer (BN powder layer) having a film thickness of about 1 μm to 20 μm. The BN powder layer has a function of easily separating the ceramic substrate 40 after the next step (sintering step S2). The BN powder layer is applied as a slurry of BN powder on one surface of each sheet-fed green sheet 30 by, for example, spraying, brush coating, roll coater, screen printing, or the like. The BN powder has a purity of 85% or more, and preferably has an average particle size of 1 μm to 20 μm.
　以上が、堆積工程Ｓ１４についての説明である。 The above is the explanation of the deposition step S14.
〔脱脂工程〕
　次に、脱脂工程Ｓ１５について説明する。本工程は、枚葉グリーンシート３０に含まれるバインダー及び可塑剤を、次の工程（焼結工程Ｓ２）の前に脱脂する。
　本工程では、一例として、堆積工程Ｓ１４で重ねた複数の枚葉グリーンシート３０（図３Ａ参照）を４５０℃～７５０℃の温度環境下で、０．５時間～２０時間保持する。その結果、複数の枚葉グリーンシート３０に含まれるバインダー及び可塑剤が脱脂される。 [Solvent degreasing process]
Next, the degreasing step S15 will be described. In this step, the binder and plasticizer contained in the single-wafer green sheet 30 are degreased before the next step (sintering step S2).
In this step, as an example, a plurality of single-wafer green sheets 30 (see FIG. 3A) stacked in the deposition step S14 are held in a temperature environment of 450 ° C. to 750 ° C. for 0.5 hours to 20 hours. As a result, the binder and the plasticizer contained in the plurality of single-wafer green sheets 30 are degreased.
　以上が、脱脂工程Ｓ１５についての説明である。また、以上が、本実施形態のグリーンシート形成工程Ｓ１についての説明である。 The above is the explanation of the degreasing step S15. Further, the above is the description of the green sheet forming step S1 of the present embodiment.
＜焼結工程＞
　次に、焼結工程Ｓ２について、図３Ａ～図３Ｒを参照しながら説明する。本工程は、堆積工程Ｓ１４で重ねられて、脱脂工程Ｓ１５でバインダー及び可塑剤が脱脂された複数の枚葉グリーンシート３０（以下、図３Ａの複数の枚葉グリーンシート３０という。）を、焼結装置（図示省略）を用いて焼結させる。 <Sintering process>
Next, the sintering step S2 will be described with reference to FIGS. 3A to 3R. In this step, a plurality of single-wafer green sheets 30 (hereinafter referred to as a plurality of single-wafer green sheets 30 in FIG. 3A), which are stacked in the deposition step S14 and degreased by the binder and the plasticizer in the degreasing step S15, are baked. Sinter using a binder (not shown).
　焼結装置は、焼結炉と、制御装置とを備える。焼結炉は、温度調整機構と、焼成室と、焼成室内の温度を計測する温度計とを有する。温度調整機構は、焼成室内を昇温する昇温部（一例としてヒーター）及び焼成室内を冷却する冷却部（一例として水冷管）を有する。そして、本工程では、図３Ａの複数の枚葉グリーンシート３０を焼結室内に配置した状態で、焼成室内の温度が後述する温度制御プログラムに従う温度で変化するように、制御装置が温度調整機構を制御する。 The sintering device includes a sintering furnace and a control device. The sintering furnace has a temperature control mechanism, a firing chamber, and a thermometer for measuring the temperature in the firing chamber. The temperature adjusting mechanism includes a temperature raising unit (as an example, a heater) for raising the temperature in the firing chamber and a cooling unit (for example, a water cooling pipe) for cooling the firing chamber. Then, in this step, in a state where the plurality of single-wafer green sheets 30 of FIG. 3A are arranged in the sintering chamber, the control device is a temperature adjusting mechanism so that the temperature in the firing chamber changes according to the temperature control program described later. To control.
　温度制御プログラムは、制御装置が有する記憶装置（例えば、ＲＯＭ等）に記憶されている。そして、温度制御プログラムを用いることで、制御装置が温度計の温度情報を参照しながら温度調整機構により温度制御（例えば、ＰＩＤ制御等）を行う。具体的に、温度制御プログラムは、焼成室内の温度プロファイルを、徐熱域を有する昇温域Ｆ１と、温度保持域Ｆ２と、冷却域Ｆ３とで構成し、これらの記載順で進行するプロファイルにする（図３Ｂ参照）。以下、昇温域Ｆ１、温度保持域Ｆ２及び冷却域Ｆ３の技術的意義について説明する。 The temperature control program is stored in a storage device (for example, ROM or the like) of the control device. Then, by using the temperature control program, the control device performs temperature control (for example, PID control, etc.) by the temperature adjusting mechanism while referring to the temperature information of the thermometer. Specifically, the temperature control program comprises a temperature profile in the firing chamber including a temperature raising region F1 having a slow heating region, a temperature holding region F2, and a cooling region F3, and the profile proceeds in the order described. (See FIG. 3B). Hereinafter, the technical significance of the temperature rising region F1, the temperature holding region F2, and the cooling region F3 will be described.
〔昇温域〕
　昇温域Ｆ１は、各枚葉グリーンシート３０に含まれる焼結助剤が窒化珪素粒子の表面の酸化層と反応して液相を生成するための温度域である。本実施形態の昇温域Ｆ１は、図３Ｂに示すように、一例として約１２時間で室温から１６００℃～２０００℃の範囲内の温度（本実施形態の場合は一例として約１８００℃）まで段階的に昇温するのが好ましい。昇温域Ｆ１では、α型窒化珪素の粒成長が抑えられ、液相化した焼結助剤中で窒化珪素粒子が再配列して緻密化する。その結果、次の温度保持域Ｆ２を経て、空孔径及び気孔率が小さく、曲げ強度が強く、熱伝導率の高いセラミック基板４０が得られる。 [Rising temperature range]
The temperature rise region F1 is a temperature region for the sintering aid contained in each single-wafer green sheet 30 to react with the oxide layer on the surface of the silicon nitride particles to form a liquid phase. As shown in FIG. 3B, the temperature rising region F1 of the present embodiment is, for example, in about 12 hours from room temperature to a temperature within the range of 1600 ° C. to 2000 ° C. (in the case of the present embodiment, about 1800 ° C. as an example). It is preferable to raise the temperature in a specific manner. In the temperature rising region F1, the grain growth of α-type silicon nitride is suppressed, and the silicon nitride particles are rearranged and densified in the liquid-phased sintering aid. As a result, a ceramic substrate 40 having a small pore diameter and a small porosity, a strong bending strength, and a high thermal conductivity can be obtained through the next temperature holding region F2.
〔温度保持域〕
　温度保持域Ｆ２は、昇温域Ｆ１で生成された液相から、窒化珪素粒子の再配列、β型窒化珪素結晶の生成及び窒化珪素結晶の粒成長を増進させ、焼結体であるセラミック基板４０を更に緻密化させるための温度域である。
　温度保持域Ｆ２の温度は、β型窒化珪素粒子の大きさ及びアスペクト比（長軸と短軸の比）、焼結助剤の揮発による空孔の形成等を考慮して、１６００℃～２０００℃の範囲内の温度とし、保持時間を１時間～３０時間（本実施形態の場合は一例として約８時間）とするのが好ましい。温度保持域Ｆ２の温度が１６００℃未満であると、セラミック基板４０が緻密化し難い。これに対して、温度保持域Ｆ２の温度が２０００℃を超えると、焼結助剤の揮発及び窒化珪素の分解が激しくなり、セラミック基板４０が緻密化し難い。なお、温度保持域Ｆ２の温度が１６００℃～２０００℃の範囲内の温度であれば、温度保持域Ｆ２の温度は時間に対して変化するように設定してもよい（例えば徐々に昇温するように設定してもよい）。
　ここで、温度保持域Ｆ２の温度はより好ましくは１７５０℃～１９５０℃の範囲内の温度であり、更に好ましくは１８００℃～１９００℃の範囲内の温度である。さらに、温度保持域Ｆ２の温度は徐熱域Ｆ１の温度の上限より５０℃以上高いことが好ましく、更に好ましくは１００℃～３００℃以上高い温度である。温度保持域Ｆ２の保持時間は２時間～２０時間がより好ましく、更に好ましくは３時間～１０時間である。 [Temperature holding range]
The temperature holding region F2 is a ceramic substrate which is a sintered body by promoting rearrangement of silicon nitride particles, formation of β-type silicon nitride crystals, and grain growth of silicon nitride crystals from the liquid phase generated in the temperature rising region F1. This is a temperature range for further densifying 40.
The temperature in the temperature holding range F2 is 1600 ° C. to 2000 ° C. in consideration of the size and aspect ratio (ratio of major axis to minor axis) of β-type silicon nitride particles, formation of pores due to volatilization of the sintering aid, and the like. It is preferable that the temperature is within the range of ° C. and the holding time is 1 hour to 30 hours (in the case of this embodiment, about 8 hours as an example). If the temperature of the temperature holding region F2 is less than 1600 ° C., the ceramic substrate 40 is difficult to be densified. On the other hand, when the temperature of the temperature holding region F2 exceeds 2000 ° C., the sintering aid volatilizes and silicon nitride decomposes violently, making it difficult for the ceramic substrate 40 to become dense. If the temperature of the temperature holding region F2 is within the range of 1600 ° C. to 2000 ° C., the temperature of the temperature holding region F2 may be set so as to change with time (for example, the temperature is gradually increased). May be set as).
Here, the temperature of the temperature holding region F2 is more preferably a temperature in the range of 1750 ° C. to 1950 ° C., and further preferably a temperature in the range of 1800 ° C. to 1900 ° C. Further, the temperature of the temperature holding region F2 is preferably 50 ° C. or more higher than the upper limit of the temperature of the slow heat region F1, and more preferably 100 ° C. to 300 ° C. or more higher. The holding time of the temperature holding region F2 is more preferably 2 hours to 20 hours, still more preferably 3 hours to 10 hours.
〔冷却域（急冷域を含む。）〕
　冷却域Ｆ３は、温度保持域Ｆ２で維持された液相を冷却して固化し、得られる粒界相の位置を固定するための温度域である。なお、本実施形態の冷却域Ｆ３には、後述する急冷域Ｆ４が含まれる。 [Cooling area (including quenching area)]
The cooling region F3 is a temperature region for cooling and solidifying the liquid phase maintained in the temperature holding region F2 and fixing the position of the obtained grain boundary phase. The cooling region F3 of the present embodiment includes a quenching region F4 described later.
　冷却域Ｆ３の冷却速度は、液相の固化を迅速に行って粒界相分布の均一性を維持するために、１００℃／時間以上が好ましく、３００℃／時間以上がより好ましく、５００℃／時間以上が更に好ましい。実用的な冷却速度は、５００℃～６００℃／時間が好ましい。以上のような冷却速度による液相の冷却によって、固化する焼結助剤の結晶化を抑制し、ガラス相を主体とした粒界相が形成される。その結果、セラミック基板４０の曲げ強度を高めることができる。
　なお、前述のとおり、冷却域Ｆ３は、温度制御プログラムにおける、昇温域Ｆ１及び温度保持域Ｆ２の後の温度域である（図３Ｂ参照）。そのため、本実施形態の冷却域Ｆ３は、昇温域Ｆ１及び温度保持域Ｆ２により焼成室内の温度が少なくとも１６００℃以上になるまで焼成室内を加熱した後に、焼成室内を冷却する温度域といえる（図３Ｂ参照）。 The cooling rate of the cooling region F3 is preferably 100 ° C./hour or more, more preferably 300 ° C./hour or more, and more preferably 500 ° C./hour, in order to rapidly solidify the liquid phase and maintain the uniformity of the grain boundary phase distribution. More than time is more preferred. The practical cooling rate is preferably 500 ° C. to 600 ° C./hour. By cooling the liquid phase at the cooling rate as described above, crystallization of the solidifying sintering aid is suppressed, and a grain boundary phase mainly composed of the glass phase is formed. As a result, the bending strength of the ceramic substrate 40 can be increased.
As described above, the cooling region F3 is the temperature region after the temperature rising region F1 and the temperature holding region F2 in the temperature control program (see FIG. 3B). Therefore, the cooling region F3 of the present embodiment can be said to be a temperature region in which the firing chamber is cooled after the firing chamber is heated by the temperature raising region F1 and the temperature holding region F2 until the temperature in the firing chamber reaches at least 1600 ° C. ( See FIG. 3B).
　次に、急冷域Ｆ４について図３Ｂを参照しながら説明する。本実施形態の冷却域Ｆ３は、その進行の途中で更に冷却温速度を大きくする温度領域を有する。本実施形態では、この「更に冷却速度を大きくする温度領域」のことを、急冷域Ｆ４という。本実施形態の急冷域Ｆ４は、一例として焼成室内の温度が６５０℃以下のいずれかの温度になった場合に開始される。なお、本実施形態において、急冷域Ｆ４を行う時間は、一例として、冷却域Ｆ３を行う時間の約半分以下の時間となっている。なお、冷却域Ｆ３に急冷域Ｆ４を設定することの技術的意義（図３Ｃ～図３Ｒ等参照）については後述する。
　本工程が終了すると、複数のセラミック基板４０が重ねられた状態で製造される（図３Ａ参照）。 Next, the quenching region F4 will be described with reference to FIG. 3B. The cooling region F3 of the present embodiment has a temperature region in which the cooling temperature rate is further increased in the middle of the progress. In the present embodiment, this "temperature region in which the cooling rate is further increased" is referred to as a quenching region F4. The quenching region F4 of the present embodiment is started when, for example, the temperature in the firing chamber reaches any temperature of 650 ° C. or lower. In the present embodiment, the time for performing the quenching region F4 is, for example, about half or less of the time for performing the cooling region F3. The technical significance of setting the quenching region F4 in the cooling region F3 (see FIGS. 3C to 3R, etc.) will be described later.
When this step is completed, a plurality of ceramic substrates 40 are manufactured in a stacked state (see FIG. 3A).
　以上が、焼結工程Ｓ２についての説明である。 The above is the explanation of the sintering process S2.
＜外周部分切断工程＞
　次に、外周部分切断工程Ｓ３について、図４Ａを参照しながら説明する。本工程は、焼結工程Ｓ２を経て製造されたセラミック基板４０の全周縁側の部分を切断する工程（切断工程）である。具体的には、本工程では、レーザー加工機（図示省略）を用いて、焼結工程Ｓ２後のセラミック基板４０の全周縁側の一例として３ｍｍ以下の幅の部分を切断する。この場合、レーザー加工機のレーザー光源は、切断する部分に沿ってレーザー光を間欠的に照射する。その結果、セラミック基板４０の切断面（端面）になる位置には、レーザー光源の走査速度と照射時間とに起因する定められた間隔ｐ１で、直線状に並ぶ複数の凹みにより構成されるスクライブラインＳＬが形成される。そして、例えば、定められた間隔ｐ１が９０μｍ以上１１０μｍ以下である場合、各凹みから端部の板厚方向の全域にマイクロクラックＭＣ（クラックの一例）が形成される（図６Ｂ参照）。
　図６Ｃのセラミック基板４０はスクライブラインＳＬで全周縁側の所定幅を切断した後の状態の一部斜視図（ここでは矩形の一角部分の斜視図）を示す。このセラミック基板４０の厚さＴ１は３２０μｍである。セラミック基板４０の表面４０Ａ１の端部（主面端部４０Ａ３）にはスクライブラインＳＬに対応する部分に複数の凹みが上記間隔ｐ１で形成されている。この主面端部４０Ａ３の凹みから面内方向に、その板厚方向の一端（表面４０Ａ１）から他端（裏面４０Ａ２）に亘る、複数本のマイクロクラックＭＣが形成される。この場合、各マイクロクラックＭＣの長さＬ１１（すなわち主面（すなわち表面４０Ａ１）において主面端部４０Ａ３から面内方向に延びるように現れたマイクロクラックＭＣの長さＬ１１）は、一例として、１５～２５μｍである。また、マイクロクラックＭＣの端面４０Ａ４に現れた部分の長さＬ２１は２５０～３２０μｍである。
　以上より、本工程が終了すると、全周縁の部分が切断され、端部の周方向全域に亘って複数本のマイクロクラックＭＣが形成されたセラミック基板４０が製造される。 <Outer peripheral part cutting process>
Next, the outer peripheral partial cutting step S3 will be described with reference to FIG. 4A. This step is a step (cutting step) of cutting a portion on the entire peripheral edge side of the ceramic substrate 40 manufactured through the sintering step S2. Specifically, in this step, a laser processing machine (not shown) is used to cut a portion having a width of 3 mm or less as an example of the entire peripheral edge side of the ceramic substrate 40 after the sintering step S2. In this case, the laser light source of the laser processing machine intermittently irradiates the laser beam along the portion to be cut. As a result, at the position of the cut surface (end surface) of the ceramic substrate 40, a scribing line composed of a plurality of dents arranged in a straight line at a predetermined interval p1 due to the scanning speed and irradiation time of the laser light source. SL is formed. Then, for example, when the defined interval p1 is 90 μm or more and 110 μm or less, microcracks MC (an example of cracks) are formed in the entire area from each recess in the plate thickness direction at the end (see FIG. 6B).
The ceramic substrate 40 of FIG. 6C shows a partial perspective view (here, a perspective view of a corner portion of a rectangle) in a state after cutting a predetermined width on the entire peripheral edge side with a scribe line SL. The thickness T1 of the ceramic substrate 40 is 320 μm. A plurality of dents are formed at the end portion (main surface end portion 40A3) of the surface 40A1 of the ceramic substrate 40 at the portion corresponding to the scribe line SL at the above interval p1. A plurality of microcracks MC are formed from the recess of the main surface end portion 40A3 in the in-plane direction from one end (front surface 40A1) to the other end (back surface 40A2) in the plate thickness direction. In this case, the length L11 of each microcrack MC (that is, the length L11 of the microcrack MC appearing to extend in the in-plane direction from the main surface end portion 40A3 on the main surface (that is, the surface 40A1)) is 15 as an example. It is ~ 25 μm. Further, the length L21 of the portion appearing on the end face 40A4 of the microcrack MC is 250 to 320 μm.
From the above, when this step is completed, the ceramic substrate 40 is manufactured in which the entire peripheral edge portion is cut and a plurality of microcracks MC are formed over the entire circumferential direction of the end portion.
〔冷却域Ｆ３に急冷域Ｆ４を設定することの技術的意義〕
　まず、冷却域Ｆ３に急冷域Ｆ４を設定することの技術的意義について図３Ｂ及び図３Ｃを参照しながら説明する。
　ここで、図３Ｂは、焼結工程Ｓ２における焼成温度のプロファイル（試験により検討した条件も含む。）を示すグラフである。前述のとおり、本実施形態では、一例として焼成室内の温度が６５０℃以下のいずれかの温度になった場合に、急冷域Ｆ４が開始される。ここで、図３Ｂのグラフに示すように、本願の発明者らは、急冷域Ｆ４の開始温度（急冷開始温度）を、１２００℃、１０５０℃、８００℃、６５０℃及び４００℃に設定した場合のセラミック基板４０の反り量を測定する試験を行った。図３Ｃは、その結果のグラフ、すなわち、焼結工程Ｓ２における急冷開始温度と、反り量（前述の最大高低値）との関係を示すグラフである。図３Ｃのグラフによれば、急冷開始温度が低いほど、セラミック基板４０の反り量が小さくなる傾向になることが分かる。そして、反り量は、一例として、最大で６μｍ以下であることが好ましい。その理由は、回路パターンの形成工程（レジスト印刷工程Ｓ６及びエッチング工程Ｓ７）又は電子部品の実装工程Ｓ１０の際に容易に取り扱いが可能となるためである。そして、図３Ｃのグラフから分かるように、急冷開始温度が高いほど、反り量が大きく、反り量がばらつく。これは、急冷開始温度が高いほど、急冷によるセラミック基板４０の部分的な歪の影響が大きいことを意味する。
　一方で、図３Ｃのグラフから分かるように、急冷開始温度が４００℃と６５０℃の場合、反り量のばらつきを考慮しても、セラミック基板４０の反り量は反り量の最大許容値未満（この場合は４μｍ未満）となる。また、急冷開始温度の極端な引き下げ（例えば４００℃以下）をすると、焼成時間の延長による生産性の低下に繋がる。
　そこで、本実施形態では、反り量と、焼成時間の短縮化とのバランスを考慮し、急冷開始温度として４００℃～６５０℃が適切な範囲であるとしている。
　なお、焼成時間の短縮化を考慮しなければ、急冷開始温度を４００℃未満としてもよい。
　以上が、冷却域Ｆ３に急冷域Ｆ４を設定することの技術的意義である。 [Technical significance of setting the quenching region F4 in the cooling region F3]
First, the technical significance of setting the quenching region F4 in the cooling region F3 will be described with reference to FIGS. 3B and 3C.
Here, FIG. 3B is a graph showing a profile of the firing temperature in the sintering step S2 (including the conditions examined by the test). As described above, in the present embodiment, as an example, when the temperature in the firing chamber reaches any temperature of 650 ° C. or lower, the quenching region F4 is started. Here, as shown in the graph of FIG. 3B, when the inventors of the present application set the start temperature (quenching start temperature) of the quenching region F4 to 1200 ° C., 1050 ° C., 800 ° C., 650 ° C. and 400 ° C. A test was conducted to measure the amount of warpage of the ceramic substrate 40 of the above. FIG. 3C is a graph of the result, that is, a graph showing the relationship between the quenching start temperature in the sintering step S2 and the amount of warpage (the above-mentioned maximum high / low value). According to the graph of FIG. 3C, it can be seen that the lower the quenching start temperature, the smaller the amount of warpage of the ceramic substrate 40 tends to be. As an example, the amount of warpage is preferably 6 μm or less at the maximum. The reason is that it can be easily handled during the circuit pattern forming step (resist printing step S6 and etching step S7) or the electronic component mounting step S10. As can be seen from the graph of FIG. 3C, the higher the quenching start temperature, the larger the amount of warpage and the more the amount of warpage varies. This means that the higher the quenching start temperature, the greater the influence of the partial strain of the ceramic substrate 40 due to the quenching.
On the other hand, as can be seen from the graph of FIG. 3C, when the quenching start temperature is 400 ° C. and 650 ° C., the warp amount of the ceramic substrate 40 is less than the maximum permissible value of the warp amount even if the variation in the warp amount is taken into consideration. In the case of less than 4 μm). Further, if the quenching start temperature is extremely lowered (for example, 400 ° C. or lower), the productivity is lowered due to the extension of the firing time.
Therefore, in the present embodiment, considering the balance between the amount of warpage and the shortening of the firing time, the quenching start temperature of 400 ° C. to 650 ° C. is considered to be an appropriate range.
If the shortening of the firing time is not taken into consideration, the quenching start temperature may be set to less than 400 ° C.
The above is the technical significance of setting the quenching region F4 in the cooling region F3.
〔外周部分切断工程Ｓ３を行うことの技術的意義〕
　次に、外周部分切断工程Ｓ３を行うことの技術的意義について図４Ｂを参照しながら説明する。
　本願の発明者らは、急冷開始温度が６５０℃の場合を一例として、外周部分の切断幅を、０ｍｍ（切断無し）、３ｍｍ、６ｍｍ及び９ｍｍに設定した場合のセラミック基板４０の反り量（前述の最大高低値）を測定する試験を行った。図４Ｂは、その結果のグラフ、すなわち、外周部分切断工程Ｓ３における、外周部分の切断幅と、反り量との関係を示すグラフである。図４Ｂのグラフから分かるように、外周部分の切断幅が大きいほど、反り量が小さくなることが分かる。また、外周部分の切断幅が大きいほど、反り量のばらつきが小さくなることが分かる。この理由は、セラミック基板４０における外周部分に近い部分ほど、冷却時の影響により圧縮応力又は引張応力がかかった状態であるため、このような部分を切断することでセラミック基板４０がこれらの応力から解放されると考えられる。図４Ｂのグラフの結果を考慮すると、外周部分を切断する必要がある。ただし、セラミック基板４０の切断された外周部分は廃棄される、すなわち、切断幅が大きいほど廃棄量が増えることから、外周部分の切断幅は狭い方が好ましい。
　そこで、本実施形態では、外周部分の切断幅を３ｍｍ以下とすることが好ましい。
　また、本実施形態のセラミック基板４０の端部の全周には、複数本のマイクロクラックＭＣが形成されている。そして、複数本のマイクロクラックＭＣは、端部の周方向に定められた間隔ｐ１で並べられている。そのため、端部近傍に残る永久歪は、マイクロクラックＭＣにより解放され易くなる。すなわち、引張応力がかかる部分に対してはマイクロクラックＭＣが閉じるように変形することでその部分の引張応力が解放される。また圧縮応力がかかる部分に対してはマイクロクラックＭＣが開くように変形することでその部分の圧縮応力が解放される。以上より、端部に形成されている複数本のマイクロクラックＭＣがセラミック基板４０の端部近傍の永久歪を解放させることで、結果的にセラミック基板４０の反り量を低減させると考えられる。
　以上が、外周部分切断工程Ｓ３を行うことの技術的意義である。 [Technical significance of performing the outer peripheral partial cutting step S3]
Next, the technical significance of performing the outer peripheral partial cutting step S3 will be described with reference to FIG. 4B.
The inventors of the present application have set the cutting width of the outer peripheral portion to 0 mm (no cutting), 3 mm, 6 mm, and 9 mm, taking as an example the case where the quenching start temperature is 650 ° C., and the amount of warpage of the ceramic substrate 40 (described above). A test was conducted to measure the maximum high and low values of. FIG. 4B is a graph of the result, that is, a graph showing the relationship between the cutting width of the outer peripheral portion and the amount of warpage in the outer peripheral portion cutting step S3. As can be seen from the graph of FIG. 4B, it can be seen that the larger the cutting width of the outer peripheral portion, the smaller the amount of warpage. Further, it can be seen that the larger the cutting width of the outer peripheral portion, the smaller the variation in the amount of warpage. The reason for this is that the closer to the outer peripheral portion of the ceramic substrate 40, the more compressive stress or tensile stress is applied due to the influence of cooling. Therefore, by cutting such a portion, the ceramic substrate 40 is relieved of these stresses. It is considered to be released. Considering the result of the graph of FIG. 4B, it is necessary to cut the outer peripheral portion. However, the cut outer peripheral portion of the ceramic substrate 40 is discarded, that is, the larger the cutting width, the larger the amount of waste. Therefore, it is preferable that the cutting width of the outer peripheral portion is narrow.
Therefore, in the present embodiment, it is preferable that the cutting width of the outer peripheral portion is 3 mm or less.
Further, a plurality of microcracks MC are formed on the entire circumference of the end portion of the ceramic substrate 40 of the present embodiment. The plurality of microcracks MC are arranged at intervals p1 defined in the circumferential direction of the end portion. Therefore, the permanent strain remaining in the vicinity of the end portion is easily released by the microcrack MC. That is, the tensile stress of the portion is released by deforming the microcrack MC so as to close the portion to which the tensile stress is applied. Further, the compressive stress of the portion is released by deforming the portion to which the compressive stress is applied so that the microcrack MC opens. From the above, it is considered that the plurality of microcracks MC formed at the end portion release the permanent strain in the vicinity of the end portion of the ceramic substrate 40, and as a result, the amount of warpage of the ceramic substrate 40 is reduced.
The above is the technical significance of performing the outer peripheral partial cutting step S3.
　以上が、外周部分切断工程Ｓ３についての説明である。そして、以上が、本実施形態のセラミック基板４０の製造方法についての説明である。 The above is the explanation of the outer peripheral partial cutting step S3. The above is a description of the method for manufacturing the ceramic substrate 40 of the present embodiment.
＜スクライブライン形成工程＞
　次に、ＳＬ形成工程Ｓ４について、図５を参照しながら説明する。本工程は、セラミック基板４０の一方の面（本実施形態では一例として表面４０Ａ１）に、複数本（本実施形態では一例として３本）のスクライブラインＳＬを形成する。本工程が終了すると、ＳＬ付きセラミック基板４０Ａが製造される。
　本工程では、セラミック基板４０の表面４０Ａ１に、照射部（図示省略）から照射したレーザー光により一例として幅方向中央に１本、長さ方向を三等分する２本の合計３本の直線部分を形成し、表面４０Ａ１の全領域を６等分された領域に区画する。ここで、各スクライブラインＳＬは、一例として、直線状に並ぶ複数の凹みにより構成されている（図６Ｂ参照）。そのため、本工程で使用される照射部（一例として、炭酸ガスレーザー光源、ＹＡＧレーザー光源等）は、例えば、レーザー光を間欠的に照射可能となっている。
　なお、各スクライブラインＳＬは、後の工程である分割工程Ｓ９（図１参照）において、セラミック基板４０を複数（本実施形態では６枚）に分割する際の切断線として用いられる。 <Scribe line formation process>
Next, the SL forming step S4 will be described with reference to FIG. In this step, a plurality of scribe lines SL (three lines as an example in this embodiment) are formed on one surface of the ceramic substrate 40 (surface 40A1 as an example in this embodiment). When this step is completed, the ceramic substrate 40A with SL is manufactured.
In this step, a total of three straight lines, one in the center in the width direction and two in the length direction are divided into three equal parts by the laser beam irradiated from the irradiation portion (not shown) on the surface 40A1 of the ceramic substrate 40 as an example. Is formed, and the entire region of the surface 40A1 is divided into six equal parts. Here, as an example, each scribe line SL is composed of a plurality of dents arranged in a straight line (see FIG. 6B). Therefore, the irradiation unit (for example, a carbon dioxide laser light source, a YAG laser light source, etc.) used in this step can intermittently irradiate laser light, for example.
Each scribe line SL is used as a cutting line when the ceramic substrate 40 is divided into a plurality of (six in the present embodiment) in the dividing step S9 (see FIG. 1), which is a later step.
　以上が、ＳＬ形成工程Ｓ４についての説明である。 The above is the explanation of the SL forming step S4.
＜金属層形成工程＞
　次に、金属層形成工程Ｓ５について、図６Ａ及び図６Ｂを参照しながら説明する。
　本工程では、第１金属層５０Ａ及び第２金属層５０Ｂを、それぞれ、ＳＬ付きセラミック基板４０Ａの表面４０Ａ１側及び裏面４０Ａ２側に固定する。この場合、第１金属層５０Ａ及び第２金属層５０Ｂは、それぞれ、ろう材（図示省略）を介して、表面４０Ａ１側及び裏面４０Ａ２側に固定される。具体的には、セラミック基板４０の表面４０Ａ１及び裏面４０Ａ２に、ロールコーター法、スクリーン印刷法、転写法等の方法によりペースト状のろう材を均一に塗布し、さらに、均一に塗布したペースト状のろう材を介してセラミック基板４０の表面４０Ａ１及び裏面４０Ａ２にそれぞれ第１金属層５０Ａ及び第２金属層５０Ｂを接合する。ここで、本工程では、ペースト状のろう材を均一に塗布する点で、スクリーン印刷法が好ましい。また、この場合、ペースト状のろう材の粘土を５Ｐａ・ｓ～２０Ｐａ・ｓに制御することが好ましい。ペースト状のろう材中の有機溶剤量は５質量％～７質量％、バインダー量は２質量％～８質量％の範囲で配合することにより優れたペースト状のろう材を得ることができる。本工程が終了すると、マザーボード６０が製造される。
　なお、図６Ｂには、スクライブラインＳＬを構成する複数の凹みのそれぞれから裏面４０Ａ２に亘るマイクロクラックＭＣが形成されている状態を図示しているが、マイクロクラックＭＣは、後述する分割工程Ｓ９時に形成される。また、マイクロクラックＭＣは、前述の外周部分切断工程Ｓ３時にも形成される。 <Metal layer forming process>
Next, the metal layer forming step S5 will be described with reference to FIGS. 6A and 6B.
In this step, the first metal layer 50A and the second metal layer 50B are fixed to the front surface 40A1 side and the back surface 40A2 side of the ceramic substrate 40A with SL, respectively. In this case, the first metal layer 50A and the second metal layer 50B are fixed to the front surface 40A1 side and the back surface 40A2 side, respectively, via a brazing material (not shown). Specifically, a paste-like brazing material is uniformly applied to the front surface 40A1 and the back surface 40A2 of the ceramic substrate 40 by a method such as a roll coater method, a screen printing method, or a transfer method, and further, the paste-like material is uniformly applied. The first metal layer 50A and the second metal layer 50B are joined to the front surface 40A1 and the back surface 40A2 of the ceramic substrate 40 via a brazing material, respectively. Here, in this step, the screen printing method is preferable in that the paste-like brazing material is uniformly applied. Further, in this case, it is preferable to control the clay of the paste-like brazing material to 5 Pa · s to 20 Pa · s. An excellent paste-like brazing material can be obtained by blending the amount of the organic solvent in the paste-like brazing material in the range of 5% by mass to 7% by mass and the amount of the binder in the range of 2% by mass to 8% by mass. When this process is completed, the motherboard 60 is manufactured.
Note that FIG. 6B illustrates a state in which microcracks MC extending from each of the plurality of dents constituting the scribe line SL to the back surface 40A2 are formed. It is formed. The microcrack MC is also formed during the above-mentioned outer peripheral portion cutting step S3.
　以上が、金属層形成工程Ｓ５についての説明である。 The above is the explanation of the metal layer forming step S5.
＜レジスト印刷工程＞
　次に、レジスト印刷工程Ｓ６について、図７を参照しながら説明する。本工程は、マザーボード６０の第１金属層５０Ａに感光性を有するレジスト膜ＰＲＦを被覆し、第１金属層５０Ａにおける３本のスクライブラインＳＬにより区画されている６つの領域に、後述する各回路パターンＣＰに相当するレジストパターンＰＲＰを形成する。具体的には、本工程では、一例として露光装置（図示省略）を用いて、レジスト膜ＰＲＦにレジストパターンＰＲＰを印刷する（レジストパターンＰＲＰを硬化させ、レジスト膜ＰＲＦにおけるレジストパターンＰＲＰ以外の部分を未硬化のままとする）。その結果、ＰＲＰ付きマザーボード６０Ａが製造される。 <Resist printing process>
Next, the resist printing step S6 will be described with reference to FIG. 7. In this step, the first metal layer 50A of the motherboard 60 is coated with a photosensitive resist film PRF, and the six regions defined by the three scribing lines SL in the first metal layer 50A are each circuit described later. A resist pattern PRP corresponding to the pattern CP is formed. Specifically, in this step, as an example, an exposure apparatus (not shown) is used to print a resist pattern PRP on the resist film PRF (the resist pattern PRP is cured, and a portion of the resist film PRF other than the resist pattern PRP is printed. Leave uncured). As a result, the motherboard 60A with PRP is manufactured.
　以上が、レジスト印刷工程Ｓ６についての説明である。 The above is the explanation of the resist printing process S6.
＜エッチング工程＞
　次に、エッチング工程Ｓ７（回路パターン形成工程の一例）について、図８を参照しながら説明する。本工程は、ＰＲＰ付きマザーボード６０Ａのレジスト膜ＰＲＦにおける未硬化のレジスト膜ＰＲＦを除去し、第１金属層５０Ａが露出した部分をエッチングし、次いで残ったレジストパターンＰＲＰを除去して、回路パターンＣＰを形成する。その結果、本工程前のＰＲＰ付きマザーボード６０Ａは、３本のスクライブラインＳＬに区画されている６つの領域にそれぞれ回路パターンＣＰが形成された集合基板６０Ｂとなる。また、集合基板６０Ｂが形成されると、ＳＬ形成工程Ｓ４で形成された３本のスクライブラインＳＬのすべての部分は、第１金属層５０Ａのエッチングに伴って露出された状態となる。
　なお、本工程で形成される各回路パターンＣＰには、後述する実装工程Ｓ１０で、それぞれ、ＩＣ、コンデンサ、抵抗等の電子部品（図示省略）が実装される。また、前述の説明では、エッチング工程Ｓ７を回路パターン形成工程の一例としているが、レジスト印刷工程Ｓ６とエッチング工程Ｓ７との組み合せを回路パターン形成工程の一例と捉えてもよい。 <Etching process>
Next, the etching step S7 (an example of the circuit pattern forming step) will be described with reference to FIG. In this step, the uncured resist film PRF in the resist film PRF of the motherboard 60A with PRP is removed, the exposed portion of the first metal layer 50A is etched, and then the remaining resist pattern PRP is removed to remove the circuit pattern CP. To form. As a result, the motherboard 60A with PRP before this step becomes a collective substrate 60B in which the circuit pattern CP is formed in each of the six regions partitioned by the three scribe lines SL. Further, when the assembly substrate 60B is formed, all the portions of the three scribe lines SL formed in the SL forming step S4 are exposed as the first metal layer 50A is etched.
Electronic components (not shown) such as ICs, capacitors, and resistors are mounted on each circuit pattern CP formed in this step in the mounting step S10 described later. Further, in the above description, the etching step S7 is taken as an example of the circuit pattern forming step, but the combination of the resist printing step S6 and the etching step S7 may be regarded as an example of the circuit pattern forming step.
　以上が、エッチング工程Ｓ７についての説明である。 The above is the explanation of the etching process S7.
＜表面処理工程＞
　次に、表面処理工程Ｓ８について説明する。本工程は、集合基板６０Ｂの複数の（本実施形態では６個の）回路パターンＣＰが形成されている側の面における、電子部品が接合される接合部分以外の部分をソルダーレジスト等の保護層（図示省略）で被覆して、当該接合部分以外の部分の表面処理を行う。また、本工程は、電子部品が接合される接合部分に例えば電解めっき法によりめっき処理をして、当該接合部分の表面処理を行う。ここで、前述の説明では、エッチング工程Ｓ７の終了時の製造物を集合基板６０Ｂとしたが、表面処理工程Ｓ８の終了時の製造物、すなわち、集合基板６０Ｂを保護層で被覆した基板を集合基板と捉えてもよい。 <Surface treatment process>
Next, the surface treatment step S8 will be described. In this step, a protective layer such as a solder resist is formed on the surface of the assembly substrate 60B on the side where a plurality of circuit pattern CPs (six in this embodiment) are formed, except for the bonding portion where the electronic components are bonded. (Not shown) is covered, and the surface treatment of the portion other than the joint portion is performed. Further, in this step, the joint portion to which the electronic component is joined is plated by, for example, an electrolytic plating method, and the surface treatment of the joint portion is performed. Here, in the above description, the product at the end of the etching step S7 is the assembly substrate 60B, but the product at the end of the surface treatment step S8, that is, the substrate in which the assembly substrate 60B is coated with the protective layer is assembled. You may think of it as a substrate.
　以上が、表面処理工程Ｓ８についての説明である。 The above is the explanation of the surface treatment step S8.
＜分割工程＞
　次に、分割工程Ｓ９について、図９を参照しながら説明する。本工程は、集合基板６０Ｂ（又はＳＬ付きセラミック基板４０Ａ）を複数本（本実施形態では一例として３本）のスクライブラインＳＬに沿って切断して、集合基板６０Ｂを複数（本実施形態では一例として６枚）の回路基板６０Ｃに分割する。 <Division process>
Next, the division step S9 will be described with reference to FIG. In this step, a plurality of assembly boards 60B (or ceramic substrates 40A with SL) are cut along a plurality of (three as an example in this embodiment) scribing line SL, and a plurality of assembly boards 60B (one example in this embodiment) are cut. 6 sheets) are divided into circuit boards 60C.
　本工程が終了すると、複数の回路基板６０Ｃが製造される。なお、本実施形態の場合、第１金属層５０Ａは、これまでの工程により、各回路基板６０Ｃの回路パターンＣＰとなる。これに対して、第２金属層５０Ｂにおける、３本のスクライブラインＳＬにより区画された領域は、これまでの工程により、各回路基板６０Ｃにおける回路パターンＣＰが形成されている側と反対側の金属層となる。そして、当該金属層は、後述する実装工程Ｓ１０により製造される実装基板（図示省略）の使用時において、回路パターンＣＰに実装される電子部品が発生させる熱を放熱するための放熱層として機能する。
　なお、本工程ではスクライブラインＳＬにより集合基板６０Ｂを複数の回路基板６０Ｃに分割することから、当該分割により形成された各回路基板６０Ｂの端部には外周部分切断工程Ｓ３の場合と同様に、複数本のマイクロクラックＭＣが形成される。すなわち、回路基板６０Ｂのセラミック基板４０に着目した場合、図６Ｃに示すような態様の複数本のマイクロクラックＭＣが形成される。そのため、本工程が終了すると、分割後の各回路基板６０Ｂの反り量は、集合基板６０Ｂの（分割前の）状態の各回路基板６０Ｃの反り量に比べて低減される。 When this step is completed, a plurality of circuit boards 60C are manufactured. In the case of the present embodiment, the first metal layer 50A becomes the circuit pattern CP of each circuit board 60C by the steps so far. On the other hand, in the second metal layer 50B, the region partitioned by the three scribe lines SL is the metal on the side opposite to the side on which the circuit pattern CP is formed in each circuit board 60C by the steps so far. Become a layer. Then, the metal layer functions as a heat radiating layer for radiating heat generated by electronic components mounted on the circuit pattern CP when the mounting board (not shown) manufactured in the mounting step S10 described later is used. ..
In this step, since the assembly board 60B is divided into a plurality of circuit boards 60C by the scribing line SL, the end portion of each circuit board 60B formed by the division is divided into the outer peripheral portion cutting step S3 as in the case of the outer peripheral portion cutting step S3. A plurality of microcracks MC are formed. That is, when focusing on the ceramic substrate 40 of the circuit board 60B, a plurality of microcracks MCs having a mode as shown in FIG. 6C are formed. Therefore, when this step is completed, the amount of warpage of each circuit board 60B after division is reduced as compared with the amount of warpage of each circuit board 60C in the state (before division) of the assembly board 60B.
　以上が、分割工程Ｓ９についての説明である。
　なお、これまでの本実施形態の製造方法の説明では、マザーボード６０に対して金属層形成工程Ｓ５を行い、その後、分割工程Ｓ９を行うとしたが、例えば、スクライブライン形成工程Ｓ４の次に分割工程Ｓ９を行ってから金属層形成工程Ｓ５から表面処理工程Ｓ８を行うようにしてもよい。 The above is the description of the division step S9.
In the description of the manufacturing method of the present embodiment so far, the metal layer forming step S5 is performed on the motherboard 60, and then the dividing step S9 is performed. The surface treatment step S8 may be performed from the metal layer forming step S5 after the step S9 is performed.
＜実装工程＞
　次に、実装工程Ｓ１０について説明する。本工程は、各回路基板６０Ｃ（図９参照）に電子部品（図示省略）を実装する。本工程は、実装装置（図示省略）を用いて、各回路基板６０Ｃの回路パターンＣＰ（図９参照）における電子部品が接合される接合部分にはんだ（図示省略）を付着させて、当該接合部分に電子部品の接合端子を接合させる。この場合、各回路基板６０Ｃの端部には、複数本のマイクロクラックＭＣが形成されているため、接合時の発熱による各回路基板６０Ｃの変形がマイクロクラックＭＣの開閉動作を生じさせる。その結果、接合時における、回路パターンＣＰの接合部分と電子部品の接合端子との位置ずれがマイクロクラックＭＣの開閉動作により抑制される。 <Mounting process>
Next, the mounting step S10 will be described. In this step, electronic components (not shown) are mounted on each circuit board 60C (see FIG. 9). In this step, a mounting device (not shown) is used to attach solder (not shown) to a joint portion where electronic components are joined in the circuit pattern CP (see FIG. 9) of each circuit board 60C, and the joint portion is attached. Join the joining terminals of electronic components to. In this case, since a plurality of microcracks MC are formed at the end of each circuit board 60C, the deformation of each circuit board 60C due to heat generation at the time of joining causes the opening and closing operation of the microcracks MC. As a result, the positional deviation between the joint portion of the circuit pattern CP and the joint terminal of the electronic component at the time of joining is suppressed by the opening / closing operation of the microcrack MC.
　本工程が終了すると、複数の実装基板が製造される。なお、前述の説明では、本工程は分割工程Ｓ９の後の工程としたが、本工程の後に分割工程Ｓ９を行うようにしてもよい。すなわち、本実施形態の製造方法Ｓ１００は、表面処理工程Ｓ８の後、実装工程Ｓ１０、分割工程Ｓ９の順で行ってもよい。 When this process is completed, multiple mounting boards will be manufactured. In the above description, this step is a step after the split step S9, but the split step S9 may be performed after the main step. That is, the manufacturing method S100 of the present embodiment may be performed in the order of the mounting step S10 and the dividing step S9 after the surface treatment step S8.
　以上が、実装工程Ｓ１０についての説明である。なお、複数の実装基板の製造後には、例えば、検査装置（図示省略）を用いて、回路パターンＣＰの検査、電子部品の動作の検査等が行われる。
　以上が、本実施形態の製造方法Ｓ１００についての説明である。 The above is the description of the mounting process S10. After manufacturing the plurality of mounting boards, for example, an inspection device (not shown) is used to inspect the circuit pattern CP, inspect the operation of electronic components, and the like.
The above is the description of the manufacturing method S100 of the present embodiment.
≪本実施形態の効果≫
　次に、本実施形態の効果について説明する。 << Effect of this embodiment >>
Next, the effect of this embodiment will be described.
＜第１の効果＞
　本実施形態のセラミック基板４０（図３Ａ、図３Ｄ、図３Ｇ、図３Ｊ、図３Ｍ、図３Ｐ等参照）は、平面視にて矩形状のセラミック基板４０であって、セラミック基板４０の対角線の長さでセラミック基板４０の板厚方向における最大高低差を除した値は、１μｍ／ｍｍ以下であり、その端部には、セラミック基板４０の主面端部４０Ａ３から面内方向に、板厚方向の一端から他端に亘る、複数本のマイクロクラックＭＣが形成されている。
　そして、前述のとおり、本実施形態のセラミック基板４０は、その両面側にそれぞれ第１金属層５０Ａ、第２金属層５０Ｂが固定されて、回路基板６０Ｃ（図９参照）に加工される。そのため、本実施形態のセラミック基板４０は、その両面側にそれぞれ第１金属層５０Ａ、第２金属層５０Ｂが固定された状態（マザーボード６０の状態）で種々の熱履歴が加わることとなる。すなわち、マザーボード６０の内部には熱歪みや熱応力が生じることとなる。特に、熱歪みや熱応力は、マザーボード６０の外周縁近傍に残留し得る。以上より、マザーボード６０の状態のセラミック基板４０の外周縁近傍には、歪エネルギーが残り易い。
　しかしながら、本実施形態のセラミック基板４０は、その端部（外周面）に、セラミック基板４０の主面端部４０Ａ３から面内方向に、その板厚方向（Ｚ方向）の一端から他端に亘る、複数本のマイクロクラックＭＣが形成されている。そして、各マイクロクラックＭＣは、セラミック基板４０の外周縁近傍の歪エネルギーを解放させる、すなわち、低減させるように機能する。
　また、前述のとおり、本実施形態のセラミック基板４０は、第１例～第５例のセラミック基板４０（図３Ａ、図３Ｄ、図３Ｇ、図３Ｊ、図３Ｍ、図３Ｐ等参照）やその他の例示のように、その板厚方向における凹凸状態（反り状態）が異なる形態を含む。しかしながら、本実施形態のセラミック基板４０は、いずれの場合であっても、最大高低値が１μｍ以下である。そのうえで、本実施形態のセラミック基板４０の端部（外周面）には、セラミック基板４０の主面端部４０Ａ３から面内方向に、その板厚方向（Ｚ方向）の一端から他端に亘る、複数本のマイクロクラックＭＣが形成されている（図６Ｂ、図６Ｃ参照）。そのため、本実施形態のセラミック基板４０は、上記いずれの場合であっても、複数本のマイクロクラックＭＣの上記機能により、最大高低値を１μｍ以下に維持できるともいえる。
　したがって、本実施形態のセラミック基板４０を用いれば、残留熱歪みや残留熱応力が顕著に低減された平坦性に優れる高い信頼性の回路基板を作製し得る。 <First effect>
The ceramic substrate 40 of the present embodiment (see FIGS. 3A, 3D, 3G, 3J, 3M, 3P, etc.) is a rectangular ceramic substrate 40 in a plan view, and is a diagonal line of the ceramic substrate 40. The value obtained by dividing the maximum height difference of the ceramic substrate 40 in the plate thickness direction by the length is 1 μm / mm or less, and the plate thickness is at the end thereof in the in-plane direction from the main surface end portion 40A3 of the ceramic substrate 40. A plurality of microcracks MC are formed from one end to the other end in the direction.
Then, as described above, the ceramic substrate 40 of the present embodiment is processed into a circuit board 60C (see FIG. 9) by fixing the first metal layer 50A and the second metal layer 50B on both side surfaces thereof, respectively. Therefore, in the ceramic substrate 40 of the present embodiment, various thermal histories are added in a state where the first metal layer 50A and the second metal layer 50B are fixed on both side surfaces thereof (the state of the motherboard 60), respectively. That is, thermal strain and thermal stress are generated inside the motherboard 60. In particular, thermal strain and thermal stress may remain in the vicinity of the outer peripheral edge of the motherboard 60. From the above, strain energy tends to remain in the vicinity of the outer peripheral edge of the ceramic substrate 40 in the state of the motherboard 60.
However, the ceramic substrate 40 of the present embodiment extends from one end to the other end in the thickness direction (Z direction) of the ceramic substrate 40 in the in-plane direction from the main surface end portion 40A3 of the ceramic substrate 40 at its end (outer peripheral surface). , A plurality of microcracks MC are formed. Then, each microcrack MC functions to release, that is, reduce the strain energy in the vicinity of the outer peripheral edge of the ceramic substrate 40.
Further, as described above, the ceramic substrate 40 of the present embodiment includes the ceramic substrates 40 of the first to fifth examples (see FIGS. 3A, 3D, 3G, 3J, 3M, 3P, etc.) and others. As an example, it includes a form in which the uneven state (warped state) in the plate thickness direction is different. However, in any case, the ceramic substrate 40 of the present embodiment has a maximum height value of 1 μm or less. Then, the end portion (outer peripheral surface) of the ceramic substrate 40 of the present embodiment extends from one end to the other end in the plate thickness direction (Z direction) in the in-plane direction from the main surface end portion 40A3 of the ceramic substrate 40. A plurality of microcracks MC are formed (see FIGS. 6B and 6C). Therefore, it can be said that the ceramic substrate 40 of the present embodiment can maintain the maximum height value of 1 μm or less by the above-mentioned functions of the plurality of microcracks MC in any of the above cases.
Therefore, by using the ceramic substrate 40 of the present embodiment, it is possible to produce a highly reliable circuit board having excellent flatness in which residual thermal strain and residual thermal stress are remarkably reduced.
＜第２の効果＞
　また、本実施形態のセラミック基板４０では、複数本のマイクロクラックＭＣは、セラミック基板４０の端部の全周に亘って形成されている。
　したがって、本実施形態のセラミック基板４０を用いれば、その全周に亘って残留熱歪みや残留熱応力が顕著に低減された平坦性に優れる高い信頼性の回路基板を作製し得る。 <Second effect>
Further, in the ceramic substrate 40 of the present embodiment, a plurality of microcracks MC are formed over the entire circumference of the end portion of the ceramic substrate 40.
Therefore, by using the ceramic substrate 40 of the present embodiment, it is possible to produce a highly reliable circuit board having excellent flatness in which residual thermal strain and residual thermal stress are remarkably reduced over the entire circumference thereof.
＜第３の効果＞
　また、本実施形態のセラミック基板４０では、複数本のマイクロクラックＭＣは、セラミック基板４０の端部の周方向に定められた間隔ｐ１で並べられている。
　したがって、本実施形態のセラミック基板４０を用いれば、その全周に亘りバランス良く残留熱歪みや残留熱応力が顕著に低減された平坦性に優れる高い信頼性の回路基板を作製し得る。 <Third effect>
Further, in the ceramic substrate 40 of the present embodiment, the plurality of microcracks MC are arranged at intervals p1 defined in the circumferential direction of the end portion of the ceramic substrate 40.
Therefore, by using the ceramic substrate 40 of the present embodiment, it is possible to produce a highly reliable circuit board having excellent flatness in which residual thermal strain and residual thermal stress are remarkably reduced over the entire circumference thereof in a well-balanced manner.
＜第４の効果＞
　また、本実施形態のセラミック基板４０は、単に複数本のマイクロクラックＭＣがセラミック基板４０の端部の周方向に並べられているのではなく、９０μｍ以上１１０μｍ以下の間隔で並べられ、かつ、複数本のマイクロクラックＭＣの長さＬ１１（すなわち主面である表面４０Ａ１の主面端部４０Ａ３から面内方向に延びるように現れたマイクロクラックＭＣの長さＬ１１）が１５μｍ以上２５μｍ以下である。
　そのため、本実施形態のセラミック基板４０を用いれば、前述の第３の効果をより顕著に発揮することができる。 <Fourth effect>
Further, in the ceramic substrate 40 of the present embodiment, a plurality of microcracks MC are not simply arranged in the circumferential direction of the end portion of the ceramic substrate 40, but are arranged at intervals of 90 μm or more and 110 μm or less, and a plurality. The length L11 of the microcrack MC of the book (that is, the length L11 of the microcrack MC appearing to extend in the in-plane direction from the main surface end 40A3 of the surface 40A1 which is the main surface) is 15 μm or more and 25 μm or less.
Therefore, if the ceramic substrate 40 of the present embodiment is used, the above-mentioned third effect can be exhibited more remarkably.
＜第５の効果＞
　本実施形態のマザーボード６０は、図６Ａ及び図６Ｂに示されるように、セラミック基板４０と、セラミック基板４０の表面４０Ａ１側に固定されている第１金属層５０Ａと、セラミック基板４０における裏面４０Ａ２側に固定されている第２金属層５０Ｂと、を備える。
　そして、本実施形態のマザーボード６０が備えるセラミック基板４０は、前述の第１～第４の効果を奏する。
　したがって、本実施形態のマザーボード６０は、本実施形態のセラミック基板４０を備えることで、残留熱歪みや残留熱応力が顕著に低減され、かつ、平坦性に優れる。 <Fifth effect>
As shown in FIGS. 6A and 6B, the motherboard 60 of this embodiment has a ceramic substrate 40, a first metal layer 50A fixed to the front surface 40A1 side of the ceramic substrate 40, and a back surface 40A2 side of the ceramic substrate 40. A second metal layer 50B fixed to the surface of the metal layer 50B.
The ceramic substrate 40 included in the motherboard 60 of the present embodiment has the above-mentioned first to fourth effects.
Therefore, the motherboard 60 of the present embodiment is provided with the ceramic substrate 40 of the present embodiment, so that the residual thermal strain and the residual thermal stress are remarkably reduced and the flatness is excellent.
＜第６の効果＞
　本実施形態の回路基板６０Ｃは、図９に示されるように、セラミック基板４０と、セラミック基板４０の一方の面側（本実施形態では一例として表面４０Ａ１側）に形成されている回路パターンＣＰと、セラミック基板４０における他方の面側（本実施形態では一例として裏面４０Ａ２側）に固定されている金属層（第２金属層５０）と、を備える。
　そして、本実施形態の回路基板６０Ｃが備えるセラミック基板４０は、前述の第１～第４の効果を奏する。
　したがって、本実施形態の回路基板６０Ｃは、本実施形態のセラミック基板４０を備えることで、残留熱歪みや残留熱応力が顕著に低減され、かつ、平坦性に優れる。 <Sixth effect>
As shown in FIG. 9, the circuit board 60C of the present embodiment includes a ceramic substrate 40 and a circuit pattern CP formed on one surface side of the ceramic substrate 40 (in this embodiment, the surface 40A1 side as an example). A metal layer (second metal layer 50) fixed to the other surface side of the ceramic substrate 40 (in the present embodiment, the back surface 40A2 side as an example) is provided.
The ceramic substrate 40 included in the circuit board 60C of the present embodiment has the above-mentioned first to fourth effects.
Therefore, the circuit board 60C of the present embodiment is provided with the ceramic substrate 40 of the present embodiment, so that the residual thermal strain and the residual thermal stress are remarkably reduced and the flatness is excellent.
＜第７の効果＞
　また、本実施形態のセラミック基板４０の製造方法は、セラミック粉末を含む帯状グリーンシート２０を切断して枚葉グリーンシート３０を得る切断工程と、焼成室内に枚葉グリーンシート２０を配置して、前記焼成室内の温度が少なくとも１６００℃以上になるまで前記焼成室内を加熱した後に前記焼成室内を冷却し、枚葉グリーンシート３０を焼結させてセラミック基板４０を得る焼結工程と、焼結工程の後に冷却したセラミック基板４０の全周縁側の部分を切断する切断工程と、を含む。
　そのため、切断工程では、セラミック基板４０における、冷却時の影響により歪エネルギーが大きく残った状態である外周縁近傍の部分が切断される。
　その結果、全周縁を切断されたセラミック基板４０は、冷却時の影響により圧縮応力又は引張応力がかかった状態、すなわち、特に外周縁の応力から解放される。
　その結果、本実施形態のセラミック基板４０の製造方法によれば、残留熱歪みや残留熱応力が顕著に低減され、かつ、平坦性に優れるセラミック基板４０を製造することができる（図４Ｂ参照）。 <Seventh effect>
Further, the method for manufacturing the ceramic substrate 40 of the present embodiment includes a cutting step of cutting the strip-shaped green sheet 20 containing the ceramic powder to obtain the single-wafer green sheet 30, and arranging the single-leaf green sheet 20 in the firing chamber. A sintering step of heating the firing chamber until the temperature in the firing chamber reaches at least 1600 ° C., cooling the firing chamber, and sintering the single-wafer green sheet 30 to obtain a ceramic substrate 40, and a sintering step. A cutting step of cutting the entire peripheral edge side portion of the cooled ceramic substrate 40 is included.
Therefore, in the cutting step, the portion of the ceramic substrate 40 in the vicinity of the outer peripheral edge where a large amount of strain energy remains due to the influence of cooling is cut.
As a result, the ceramic substrate 40 whose entire peripheral edge is cut is released from a state in which compressive stress or tensile stress is applied due to the influence of cooling, that is, stress of the outer peripheral edge in particular.
As a result, according to the method for manufacturing the ceramic substrate 40 of the present embodiment, it is possible to manufacture the ceramic substrate 40 in which the residual thermal strain and the residual thermal stress are remarkably reduced and the flatness is excellent (see FIG. 4B). ..
＜第８の効果＞
　また、本実施形態のセラミック基板４０の製造方法は、切断工程において、セラミック基板４０の全周縁側の部分の周方向全周に亘りレーザー光源を走査させながらレーザー光を間欠的に照射させてセラミック基板４０を切断することでできた端部にマイクロクラックＭＣを形成する。
　そのため、スクライブラインＳＬに沿ってセラミック基板４０を切断すると、切断により形成された端部には、セラミック基板４０の主面端部４０Ａ３から面内方向に、その板厚方向（Ｚ方向）の一端から他端に亘る、複数本のマイクロクラックＭＣが形成される。そのため、前述のとおり、複数本のマイクロクラックＭＣは、セラミック基板４０の外周縁近傍の歪エネルギーを解放させる、すなわち、低減させるように機能する。
　したがって、本実施形態のセラミック基板４０の製造方法によれば、残留熱歪みや残留熱応力が顕著に低減された平坦性に優れるセラミック基板４０を製造することができる。 <Eighth effect>
Further, in the method for manufacturing the ceramic substrate 40 of the present embodiment, in the cutting step, the ceramic is intermittently irradiated with laser light while scanning the laser light source over the entire circumference of the entire peripheral edge side of the ceramic substrate 40 in the circumferential direction. A microcrack MC is formed at an end portion formed by cutting the substrate 40.
Therefore, when the ceramic substrate 40 is cut along the scribe line SL, one end in the plate thickness direction (Z direction) of the ceramic substrate 40 in the in-plane direction from the main surface end portion 40A3 of the ceramic substrate 40 is formed at the end portion formed by the cutting. A plurality of microcracks MC are formed from the to the other end. Therefore, as described above, the plurality of microcracks MC function to release, that is, reduce the strain energy in the vicinity of the outer peripheral edge of the ceramic substrate 40.
Therefore, according to the method for manufacturing the ceramic substrate 40 of the present embodiment, it is possible to manufacture the ceramic substrate 40 having excellent flatness in which residual thermal strain and residual thermal stress are remarkably reduced.
＜第９の効果＞
　また、本実施形態のセラミック基板４０の製造方法は、焼結工程において、前記焼成室内の冷却時に前記焼成室内の温度が６５０℃以下の温度になった場合に前記焼成室内の温度を急冷する（図３Ｂ参照）。
　また、本実施形態のセラミック基板４０の製造方法では、焼結工程Ｓ２の冷却域Ｆ３に急冷域Ｆ４を行う（図３Ｂ参照）。そして、急冷域Ｆ４を行う急冷開始温度は、一例として６５０℃以下に設定されている（図３Ｂ参照）。
　その結果、本実施形態のセラミック基板４０の製造方法は、焼結工程Ｓ２の冷却域Ｆ３に急冷域Ｆ４を行いつつ、外周部分切断工程Ｓ３（図１、図４Ａ及び図４Ｂ参照）を行うことで、残留熱歪みや残留熱応力が顕著に低減された平坦性に優れるセラミック基板４０を製造することができる。 <Ninth effect>
Further, in the method for manufacturing the ceramic substrate 40 of the present embodiment, in the sintering step, when the temperature in the firing chamber becomes 650 ° C. or lower when the firing chamber is cooled, the temperature in the firing chamber is rapidly cooled (the temperature in the firing chamber is rapidly cooled). See FIG. 3B).
Further, in the method for manufacturing the ceramic substrate 40 of the present embodiment, the quenching region F4 is performed in the cooling region F3 of the sintering step S2 (see FIG. 3B). The quenching start temperature for performing the quenching region F4 is set to 650 ° C. or lower as an example (see FIG. 3B).
As a result, in the method for manufacturing the ceramic substrate 40 of the present embodiment, the outer peripheral portion cutting step S3 (see FIGS. 1, 4A and 4B) is performed while performing the quenching region F4 in the cooling region F3 of the sintering step S2. Therefore, it is possible to manufacture the ceramic substrate 40 having excellent flatness in which residual thermal strain and residual thermal stress are remarkably reduced.
　以上が、本実施形態の効果についての説明である。また、以上が、本実施形態についての説明である。 The above is the explanation of the effect of this embodiment. Moreover, the above is the description about this embodiment.
≪変形例≫
　次に、本実施形態の変形例について説明する。 ≪Modification example≫
Next, a modified example of this embodiment will be described.
＜第１変形例＞
　本実施形態の製造方法Ｓ１００では、ＳＬ形成工程Ｓ４を行うとして説明した（図１参照）。しかしながら、図１０に示す第１変形例のように、外周部分切断工程Ｓ３の後にＳＬ形成工程Ｓ４を行わずに金属層形成工程Ｓ５を行うようにしてもよい。この変形例の場合、表面処理工程Ｓ８の後に分割工程Ｓ９を行うことなく実装工程Ｓ１０を行うようにすれば（図１参照）、１枚のマザーボード６０から１枚の実装基板が製造される。
　以上が、第１変形例についての説明である。 <First modification>
In the manufacturing method S100 of the present embodiment, it has been described that the SL forming step S4 is performed (see FIG. 1). However, as in the first modification shown in FIG. 10, the metal layer forming step S5 may be performed after the outer peripheral portion cutting step S3 without performing the SL forming step S4. In the case of this modification, if the mounting step S10 is performed without performing the dividing step S9 after the surface treatment step S8 (see FIG. 1), one mounting substrate is manufactured from one motherboard 60.
The above is the description of the first modification.
＜第２変形例＞
　本実施形態の説明では、各セラミック基板４０の一例を第１例～第５例（図３Ｄ～図３Ｒ参照）とした。しかしながら、セラミック基板４０の一例は、例えば、図１１Ａ～図１１Ｃに示す第２変形例のセラミック基板４０でもよい。
　以下、本変形例について図１１Ａ～図１１Ｃを参照しながら、本変形例における前述の実施形態と異なる部分についてのみ説明する。 <Second modification>
In the description of this embodiment, examples of the ceramic substrates 40 are referred to as Examples 1 to 5 (see FIGS. 3D to 3R). However, an example of the ceramic substrate 40 may be, for example, the ceramic substrate 40 of the second modification shown in FIGS. 11A to 11C.
Hereinafter, only the parts different from the above-described embodiment in the present modification will be described with reference to FIGS. 11A to 11C.
〔構成等〕
　図１１Ａは、本変形例のセラミック基板４０の平面図であって、その板厚方向（Ｚ方向）における高低度合（凹み具合）のプロファイルを付した状態の高低分布図である。図１１Ｂは、図１１Ａのセラミック基板４０の断面図であって、Ｘ０－Ｘ０切断線で切断した縦断面図（Ｘ０－Ｘ０断面）、Ｘ１－Ｘ１切断線で切断した縦断面図（Ｘ１－Ｘ１断面）及びＸ２－Ｘ２切断線で切断した縦断面図（Ｘ２－Ｘ２断面）を、それぞれＸ方向に沿って並べた図である。図１１Ｃは、図１１Ａのセラミック基板４０の断面図であって、Ｙ０－Ｙ０切断線で切断した横断面図、Ｙ１－Ｙ１切断線で切断した横断面図及びＹ２－Ｙ２切断線で切断した横断面図を、それぞれＹ方向に沿って並べた図である。 [Structure, etc.]
FIG. 11A is a plan view of the ceramic substrate 40 of the present modification, and is a height distribution diagram with a profile of the degree of height (recession) in the plate thickness direction (Z direction). FIG. 11B is a cross-sectional view of the ceramic substrate 40 of FIG. 11A, which is a vertical cross-sectional view (X 0- X 0 cross section) cut along the X 0- X 0 cutting line and a vertical section cut along the X 1- X 1 cutting line. rear view (X 1 -X 1 section) and X 2 -X 2 cut longitudinal section taken along the line diagram of (X 2 -X 2 section), diagrams arranged respectively along the X direction. 11C is a cross-sectional view of the ceramic substrate 40 of FIG. 11A, which is a cross-sectional view cut along the Y 0- Y 0 cutting line, a cross-sectional view cut along the Y 1- Y 1 cutting line, and Y 2- Y 2 It is the figure which arranged the cross-sectional view cut by the cutting line along the Y direction, respectively.
　本変形例のセラミック基板４０は、以下のような特徴を有する。 The ceramic substrate 40 of this modified example has the following features.
　本変形例のセラミック基板４０は、平面視にて、その一対の対角線（図１１Ａ中の破線）により形成される交差点Ｏをセラミック基板４０の板厚方向の基準とした場合に、一対の対角線により分けられる４つの領域のうち交差点Ｏを挟んで対向する一対の第１領域及び一対の第２領域の一方は交差点Ｏよりも板厚方向の一方側に位置し、他方は交差点Ｏよりも板厚方向の他方側に位置することである。そして、その最大高低値は、１μｍ／ｍｍ以下である。
　ここで、図１１Ｂに示すように、中心Ｏを通るＹ方向の直線Ｌ１で切断した切断面（第１切断面）は、その中心Ｏの部分が板厚方向の一方側に凸状となる円弧状を成している。別言すると、第１切断面は、中心Ｏの部分の位置が変曲点となって、板厚方向の一方側に凸状となる円弧状の面を形成している。さらに別言すると、第１切断面は、中心Ｏの部分の位置が板厚方向の一方側の位置における最も一方側の位置となって、板厚方向の一方側に凸状となる円弧状の面を形成している。この場合の中心Ｏの部分の凸状となる部分の凸量（平坦な場合（（図中の基準））に比べて凸状又は凹状になっている部分の量）をΔＺ１とする。そして、中心Ｏから幅方向の端部に亘って端部に近づくに従い、凸量はΔＺ２（＜ΔＺ１）、ΔＺ３（＜ΔＺ２）と小さくなる。ここで、凸量ΔＺ１は、一例として２５２μｍ以下である。
　また、図１１Ｃに示すように、中心Ｏを通るＸ方向の直線Ｌ２で切断した切断面（第２切断面）は、その中心Ｏの部分が板厚方向の他方側に凸状となる円弧状を成している。別言すると、第２切断面は、中心Ｏの部分の位置が変曲点となって、板厚方向の他方側に凸状となる円弧状の面を形成している。さらに別言すると、第２切断面は、中心Ｏの部分の位置が板厚方向の他方側の位置における最も他方側の位置となって、板厚方向の他方側に凸状となる円弧状の面を形成している。この場合の中心Ｏの部分の凸状となる部分の凸量（平坦な場合に比べて凸状又は凹状になっている部分の量）をΔＺ１とする。そして、中心Ｏから幅方向の端部に亘って端部に近づくに従い、凸量はΔＺ２（＞ΔＺ１）、ΔＺ３（＞ΔＺ２）と大きくなる。ここで、凸量ΔＺ１は、一例として２５２μｍ以下である。
　なお、本変形例のセラミック基板４０は、直線Ｌ１及び後述する直線Ｌ２に対して線対称となる反り状態を成している。すなわち、本変形例のセラミック基板４０は、直線Ｌ１及び直線Ｌ２に対して線対称となる立体形状を有する。
　以上より、本変形例のセラミック基板４０では、最大凸量は２５２μｍ以下であり、対角線の長さが約２５２．５ｍｍであるから、その最大高低値は、１μｍ／ｍｍ以下とである。 The ceramic substrate 40 of this modification is formed by a pair of diagonal lines when the intersection O formed by the pair of diagonal lines (broken line in FIG. 11A) is used as a reference in the plate thickness direction of the ceramic substrate 40 in a plan view. Of the four divided regions, one of the pair of the first region and the pair of the second regions facing each other across the intersection O is located on one side of the intersection O in the plate thickness direction, and the other is the plate thickness of the intersection O. It is located on the other side of the direction. The maximum height value is 1 μm / mm or less.
Here, as shown in FIG. 11B, the cut surface (first cut surface) cut along the straight line L1 in the Y direction passing through the center O is a circle in which the portion of the center O is convex on one side in the plate thickness direction. It has an arc shape. In other words, the first cut surface forms an arc-shaped surface in which the position of the central O portion serves as an inflection point and becomes convex on one side in the plate thickness direction. In other words, the first cut surface has an arcuate shape in which the position of the center O portion is the position on one side of the plate thickness direction and is convex on one side in the plate thickness direction. Forming a surface. In this case, the convex amount of the convex portion of the central O portion (the amount of the convex or concave portion as compared with the flat case ((reference in the figure))) is defined as ΔZ 1 . Then, as the convex amount approaches the end portion from the center O to the end portion in the width direction, the convex amount becomes smaller as ΔZ 2 (<ΔZ 1 ) and ΔZ 3 (<ΔZ 2). Here, the convex amount ΔZ 1 is 252 μm or less as an example.
Further, as shown in FIG. 11C, the cut surface (second cut surface) cut along the straight line L2 in the X direction passing through the center O has an arc shape in which the portion of the center O is convex toward the other side in the plate thickness direction. Is made up of. In other words, the second cut surface forms an arc-shaped surface in which the position of the central O portion serves as an inflection point and becomes convex on the other side in the plate thickness direction. In other words, the second cut surface has an arc shape in which the position of the center O portion is the position on the other side in the plate thickness direction and is convex toward the other side in the plate thickness direction. Forming a surface. In this case, the convex amount of the convex portion of the central O portion (the amount of the convex or concave portion as compared with the flat case) is defined as ΔZ 1 . Then, as the convex amount approaches the end portion from the center O to the end portion in the width direction, the convex amount increases to ΔZ 2 (> ΔZ 1 ) and ΔZ 3 (> ΔZ 2 ). Here, the convex amount ΔZ 1 is 252 μm or less as an example.
The ceramic substrate 40 of this modification is in a warped state that is line-symmetric with respect to the straight line L1 and the straight line L2 described later. That is, the ceramic substrate 40 of this modification has a three-dimensional shape that is line-symmetric with respect to the straight line L1 and the straight line L2.
From the above, in the ceramic substrate 40 of the present modification, the maximum convex amount is 252 μm or less and the diagonal length is about 252.5 mm, so that the maximum height value is 1 μm / mm or less.
　また、本変形例のセラミック基板４０は、セラミック基板４０の平面視にて中心Ｏを通りかつ四辺のうちの任意の一辺に平行な第１直線（第１直線の一例）により切断される第１切断面は、その長さ方向（Ｙ方向）の中央部分が板厚方向の一方側に向けて凸状に湾曲することである（図１１Ｂ参照）。そして、中心Ｏを通りかつ直線Ｌ１と直交する直線Ｌ２（第２直線の一例）により切断される第２切断面は、その長さ方向の中央部分が板厚方向の他方側に向けて凸状に湾曲し（図１１Ｃ参照）、その最大高低値は、１μｍ／ｍｍ以下である。 Further, the ceramic substrate 40 of the present modification is cut by a first straight line (an example of the first straight line) that passes through the center O and is parallel to any one of the four sides in the plan view of the ceramic substrate 40. The central portion of the cut surface in the length direction (Y direction) is curved in a convex shape toward one side in the plate thickness direction (see FIG. 11B). The second cut surface cut by the straight line L2 (an example of the second straight line) passing through the center O and orthogonal to the straight line L1 has a central portion in the length direction convex toward the other side in the plate thickness direction. (See FIG. 11C), and its maximum height is 1 μm / mm or less.
　また、本変形例のセラミック基板４０は、中心Ｏから直線Ｌ１に沿う方向（Ｙ方向）におけるセラミック基板４０の両端に亘る各位置の、第１切断面（Ｘ０－Ｘ０断面）に平行な第１平行切断面（図１１ＢのＸ１－Ｘ１断面及びＸ２－Ｘ２断面）は、それぞれの長さ方向の中央部分が板厚方向の一方側に向けて凸状に湾曲し、前記各位置の前記第１平行切断面は、中心Ｏから直線Ｌ１に沿う方向（Ｘ方向）におけるセラミック基板４０の両端に亘って、連続的に曲率が大きくなることである（図１１Ｂ参照）。 Further, the ceramic substrate 40 of this modified example is parallel to the first cut surface (X 0- X 0 cross section) at each position extending from both ends of the ceramic substrate 40 in the direction (Y direction) along the straight line L1 from the center O. first parallel cut surfaces (X 1 -X 1 section and X 2 -X 2 section of FIG. 11B), the central portion of each length direction is curved in a convex shape toward the one side in the thickness direction, the The first parallel cut surface at each position has a continuous increase in curvature from the center O to both ends of the ceramic substrate 40 in the direction along the straight line L1 (X direction) (see FIG. 11B).
　また、本変形例のセラミック基板４０は、中心Ｏから直線Ｌ２に沿う方向（Ｘ方向）におけるセラミック基板４０の両端に亘る各位置の、第２切断面に平行な第２平行切断面（図１１ＣのＸ１－Ｘ１断面及びＸ２－Ｘ２断面）は、それぞれの長さ方向の中央部分が板厚方向の他方側に向けて凸状に湾曲し、前記各位置の前記第２平行切断面は、中心Ｏから直線Ｌ１に沿う方向（Ｙ方向）におけるセラミック基板４０の両端に亘って、連続的に曲率が小さくなることである（図１１Ｃ参照）。 Further, the ceramic substrate 40 of the present modification is a second parallel cut surface parallel to the second cut surface at each position extending from both ends of the ceramic substrate 40 in the direction (X direction) along the straight line L2 from the center O (FIG. 11C). X 1 -X 1 section and X 2 -X 2 section) of the central portion of each length direction is convexly curved toward the other side of the plate thickness direction, wherein the second parallel cleavage at each position The surface has a continuously small curvature from the center O to both ends of the ceramic substrate 40 in the direction along the straight line L1 (Y direction) (see FIG. 11C).
　以上が、本変形例のセラミック基板４０の特徴についての説明である。そして、本変形例のセラミック基板４０は、これらの特徴を有することで、中心Ｏが鞍点となるいわゆる鞍型形状の基板を構成している。 The above is the explanation of the features of the ceramic substrate 40 of this modified example. The ceramic substrate 40 of the present modification has these characteristics, and thus constitutes a so-called saddle-shaped substrate in which the center O is a saddle point.
〔効果〕
　次に、本変形例の効果について説明する。 〔effect〕
Next, the effect of this modification will be described.
　本変形例のセラミック基板４０のその他の効果は、前述の本実施形態のセラミック基板４０の効果と同様である。 Other effects of the ceramic substrate 40 of this modification are the same as the effects of the ceramic substrate 40 of the present embodiment described above.
　以上が、本変形例の効果についての説明である。また、以上が、本変形例についての説明である。
　以上のとおり、本発明の一例について前述の実施形態（図１～図９参照）を参照しながら説明したが、本発明は前述の実施形態に限定されるものではない。本発明の技術的範囲には、例えば、下記のような形態（変形例）も含まれる。 The above is the description of the effect of this modification. Moreover, the above is the description of this modification.
As described above, an example of the present invention has been described with reference to the above-described embodiments (see FIGS. 1 to 9), but the present invention is not limited to the above-described embodiments. The technical scope of the present invention also includes, for example, the following forms (modifications).
　例えば、本実施形態の説明では、セラミック粉末の一例を窒化珪素として説明した。しかしながら、セラミック粉末の一例は他のセラミック粉末でもよい。例えば、窒化アルミニウム粉末でもよい。 For example, in the description of this embodiment, an example of ceramic powder has been described as silicon nitride. However, an example of the ceramic powder may be another ceramic powder. For example, aluminum nitride powder may be used.
　また、本実施形態のグリーンシート形成工程Ｓ１に含まれる成形工程Ｓ１２（図２Ａ参照）の説明では、ドクターブレード成形を用いて行うとした。しかしながら、スラリー１０を帯状グリーンシート２０に成形することができれば、成形工程Ｓ１２は他の方法により行われてもよい。例えば、成形工程Ｓ１２は、押出成形によって行われてもよい。 Further, in the explanation of the molding step S12 (see FIG. 2A) included in the green sheet forming step S1 of the present embodiment, it is assumed that the doctor blade molding is used. However, if the slurry 10 can be molded into the band-shaped green sheet 20, the molding step S12 may be performed by another method. For example, the molding step S12 may be performed by extrusion molding.
　また、本実施形態のグリーンシート形成工程Ｓ１に含まれる切断工程Ｓ１３（図２Ａ参照）の説明では、照射部２２４を帯状グリーンシート２０の短手方向の一端側から他端側に亘って移動させながら、帯状グリーンシート２０を切断するとした。しかしながら、結果として帯状グリーンシート２０を切断して枚葉グリーンシート３０を得ることができれば、帯状グリーンシート２０の切断箇所が本実施形態の場合のように帯状グリーンシート２０の短手方向の一端側から他端側に亘る直線部分でなくてもよい。例えば、帯状グリーンシート２０に枚葉グリーンシート３０の形をした穴を開けることで帯状グリーンシート２０から枚葉グリーンシート３０を分離する（又はくり抜く）ように、帯状グリーンシート２０を切断してもよい。すなわち、帯状グリーンシート２０を切断して得られる枚葉グリーンシート３０は、その全端面の少なくとも一部が切断面であればよい。 Further, in the description of the cutting step S13 (see FIG. 2A) included in the green sheet forming step S1 of the present embodiment, the irradiation unit 224 is moved from one end side to the other end side of the strip-shaped green sheet 20 in the lateral direction. However, it was decided to cut the strip-shaped green sheet 20. However, if the strip-shaped green sheet 20 can be cut to obtain the single-wafer green sheet 30 as a result, the cut portion of the strip-shaped green sheet 20 is one end side of the strip-shaped green sheet 20 in the lateral direction as in the case of the present embodiment. It does not have to be a straight portion extending from the other end to the other end. For example, even if the strip-shaped green sheet 20 is cut so as to separate (or hollow out) the single-leaf green sheet 30 from the strip-shaped green sheet 20 by making a hole in the strip-shaped green sheet 20 in the shape of the single-leaf green sheet 30. Good. That is, the single-wafer green sheet 30 obtained by cutting the strip-shaped green sheet 20 may have at least a part of all end faces thereof as a cut surface.
　また、本実施形態では、第１金属層５０Ａに回路パターンＣＰを形成するとして説明した。しかしながら、第１金属層５０Ａに回路パターンＣＰを形成せずに、第２金属層５０Ｂに回路パターンＣＰを形成してもよい。すなわち、パターン形成工程（レジスト印刷工程Ｓ６及びエッチング工程Ｓ７）では、第１金属層５０Ａ及び第２金属層５０Ｂのいずれか一方に、少なくとも１つの回路パターンＣＰを形成すればよい。 Further, in the present embodiment, it has been described that the circuit pattern CP is formed on the first metal layer 50A. However, the circuit pattern CP may be formed on the second metal layer 50B without forming the circuit pattern CP on the first metal layer 50A. That is, in the pattern forming step (resist printing step S6 and etching step S7), at least one circuit pattern CP may be formed on either the first metal layer 50A or the second metal layer 50B.
　また、本実施形態では、スクライブラインＳＬは、直線状に並ぶ複数の凹みであるとして説明した（図６Ｂ参照）。しかしながら、その機能を発揮することができれば、スクライブラインＳＬは、例えば、連続的な溝、長さ、幅等が異なる複数の凹み等であってもよい。 Further, in the present embodiment, the scribe line SL has been described as having a plurality of dents arranged in a straight line (see FIG. 6B). However, the scribe line SL may be, for example, a continuous groove, a plurality of dents having different lengths, widths, etc., as long as the function can be exhibited.
　また、本実施形態では、複数本のスクライブラインＳＬは、３本のスクライブラインＳＬであるとして説明した（図５参照）。しかしながら、複数本のスクライブラインＳＬは、少なくとも１本以上であればよい。 Further, in the present embodiment, the plurality of scribe lines SL has been described as being three scribe lines SL (see FIG. 5). However, the number of the plurality of scribe lines SL may be at least one or more.
　また、本実施形態では、複数本のスクライブラインＳＬはマザーボード６０を６等分するとして説明した（図５参照）。しかしながら、複数本のスクライブラインＳＬはマザーボード６０を等分しなくてもよい。 Further, in the present embodiment, it has been described that the plurality of scribe lines SL divide the motherboard 60 into six equal parts (see FIG. 5). However, the plurality of scribe lines SL do not have to divide the motherboard 60 into equal parts.
　この出願は、２０１９年１１月１５日に出願された日本出願特願２０１９－２０６７５２号を基礎とする優先権を主張し、その開示の全てをここに取り込む。 This application claims priority based on Japanese Application Japanese Patent Application No. 2019-206752 filed on November 15, 2019, and incorporates all of its disclosures herein.
１０　スラリー
２０　帯状グリーンシート
３０　枚葉グリーンシート
４０　セラミック基板
４０　セラミック基板
４０Ａ　ＳＬ付きセラミック基板
４０Ａ１　表面
４０Ａ２　裏面
４０Ａ３　主面端部
４０Ａ４　端面
５０Ａ　第１金属層 
５０Ｂ　第２金属層
６０　マザーボード（複合基板の一例）
６０Ａ　ＰＲＰ付きマザーボード
６０Ｂ　集合基板
６０Ｃ　回路基板
１００　ドクターブレード成形装置
１１０　ベルト搬送機構
１１２　ローラ
１１２Ａ　ローラ
１１２Ｂ　ローラ
１１４　ベルト
１２０　成形ユニット
１２２　収容部
１２４　ドクターブレード
１３０　加熱ユニット
２００　切断装置
２１０　シート搬送機構
２１２　支持部
２１４　第１搬送部
２１６　第２搬送部
２２０　切断部
２２２　筐体
２２４　照射部
２２６　移動機構
ＣＸ１　凸状部分
ＣＸ２　凸状部分
ＣＸ３　凸状部分
ＣＸ４　凸状部分
ＣＰ　回路パターン
Ｆ１　昇温域
Ｆ１　徐熱域
Ｆ２　温度保持域
Ｆ３　冷却域
Ｆ４　急冷域
Ｌ１　直線（第１直線）
Ｌ２　直線（第２直線）
ＬＢ　レーザー光
ＭＣ　マイクロクラック
Ｏ　交差点、中心
ＰＲＦ　レジスト膜
ＰＲＰ　レジストパターン
Ｓ１　グリーンシート形成工程
Ｓ１０　実装工程
Ｓ１１　スラリー作製工程
Ｓ１２　成形工程
Ｓ１３　切断工程
Ｓ１４　堆積工程
Ｓ１５　脱脂工程
Ｓ２　焼結工程
Ｓ３　外周部分切断工程
Ｓ４　ＳＬ形成工程（スクライブライン形成工程）
Ｓ５　金属層形成工程
Ｓ６　レジスト印刷工程
Ｓ７　エッチング工程
Ｓ８　表面処理工程
Ｓ９　分割工程
Ｓ１００　複数の実装基板の製造方法
ＳＬ　スクライブライン
ＷＣ　温風
ΔＺ１　凸量
ΔＺ２　凸量
ΔＺ３　凸量
ΔＺ４　凸量 10 Slurry 20 Band-shaped green sheet 30 Single-wafer green sheet 40 Ceramic substrate 40 Ceramic substrate 40A Ceramic substrate with SL 40A1 Front surface 40A2 Back surface 40A3 Main surface End 40A4 End surface 50A First metal layer
50B Second Metal Layer 60 Motherboard (Example of Composite Substrate)
60A Motherboard with PRP 60B Assembly board 60C Circuit board 100 Doctor blade molding device 110 Belt transfer mechanism 112 Roller 112A Roller 112B Roller 114 Belt 120 Molding unit 122 Accommodating part 124 Doctor blade 130 Heating unit 200 Cutting device 210 Sheet transfer mechanism 212 Support part 214 1st transport part 216 2nd transport part 220 Cutting part 222 Housing 224 Irradiation part 226 Moving mechanism CX1 Convex part CX2 Convex part CX3 Convex part CX4 Convex part CP Circuit pattern F1 Heating area F1 Slow heat area F2 Temperature Holding area F3 Cooling area F4 Quenching area L1 Straight line (first straight line)
L2 straight line (second straight line)
LB laser light MC microcrack O intersection, center PRF resist film PRP resist pattern S1 green sheet forming process S10 mounting process S11 slurry manufacturing process S12 molding process S13 cutting process S14 deposition process S15 degreasing process S2 sintering process S3 outer peripheral part cutting process S4 SL forming process (scribing line forming process)
S5 Metal layer forming process S6 Resist printing process S7 Etching process S8 Surface treatment process S9 Dividing process S100 Manufacturing method of multiple mounting substrates SL Scribline WC Warm air ΔZ 1 Convex amount ΔZ 2 Convex amount ΔZ 3 Convex amount ΔZ 4 Convex amount

Claims (12)

  1. 　平面視にて矩形状のセラミック基板であって、
    　前記セラミック基板の対角線の長さで前記セラミック基板の板厚方向における最大高低差を除した値は、１μｍ／ｍｍ以下であり、
    　その端部には、前記セラミック基板の主面端部から面内方向に、板厚方向の一端から他端に亘る、複数本のクラックが形成されている、
    　セラミック基板。     It is a ceramic substrate that is rectangular in plan view.
    The value obtained by dividing the diagonal length of the ceramic substrate by the maximum height difference in the plate thickness direction of the ceramic substrate is 1 μm / mm or less.
    At the end portion, a plurality of cracks are formed from one end to the other end in the plate thickness direction in the in-plane direction from the main surface end portion of the ceramic substrate.
    Ceramic substrate.
  2. 　前記複数本のクラックは、前記端部の全周に亘って形成されている、
    　請求項１に記載のセラミック基板。     The plurality of cracks are formed over the entire circumference of the end portion.
    The ceramic substrate according to claim 1.
  3. 　窒化珪素又は窒化アルミニウムを含む、
    　請求項１又は２に記載のセラミック基板。     Includes silicon nitride or aluminum nitride,
    The ceramic substrate according to claim 1 or 2.
  4. 　請求項１～３のいずれか１項に記載のセラミック基板と、
    　前記セラミック基板の表面側に固定されている第１金属層と、
    　前記セラミック基板における裏面側に固定されている第２金属層と、
    　を備える複合基板。     The ceramic substrate according to any one of claims 1 to 3 and
    The first metal layer fixed to the surface side of the ceramic substrate and
    The second metal layer fixed to the back surface side of the ceramic substrate and
    Composite substrate comprising.
  5. 　請求項１～３のいずれか１項に記載のセラミック基板と、
    　前記セラミック基板の表面側に形成されている回路パターンと、
    　前記セラミック基板における裏面側に固定されている金属層と、
    　を備える回路基板。     The ceramic substrate according to any one of claims 1 to 3 and
    The circuit pattern formed on the surface side of the ceramic substrate and
    The metal layer fixed to the back surface side of the ceramic substrate and
    Circuit board with.
  6. 　請求項１～３のいずれか１項に記載のセラミック基板の製造方法であって、
    　セラミック粉末を含む帯状グリーンシートを切断して枚葉グリーンシートを得る帯状グリーンシートの切断工程と、
    　焼成室内に前記枚葉グリーンシートを配置して、前記焼成室内の温度が少なくとも１６００℃以上になるまで前記焼成室内を加熱した後に前記焼成室内を冷却し、前記枚葉グリーンシートを焼結させて前記セラミック基板を得る焼結工程と、
    　前記焼結工程の後に冷却した前記セラミック基板の全周縁側の部分を切断するセラミック基板の切断工程と、
    　を含むセラミック基板の製造方法。     The method for manufacturing a ceramic substrate according to any one of claims 1 to 3.
    The cutting process of the strip-shaped green sheet to obtain a single-wafer green sheet by cutting the strip-shaped green sheet containing ceramic powder,
    The single-wafer green sheet is placed in the firing chamber, the firing chamber is heated until the temperature in the firing chamber reaches at least 1600 ° C., and then the firing chamber is cooled to sinter the single-wafer green sheet. The sintering process for obtaining the ceramic substrate and
    A ceramic substrate cutting step of cutting the entire peripheral edge side of the ceramic substrate cooled after the sintering step, and a step of cutting the ceramic substrate.
    A method for manufacturing a ceramic substrate including.
  7. 　前記セラミック基板の切断工程では、前記セラミック基板の全周縁側の部分の周方向全周に亘りレーザー光源を走査させながらレーザー光を間欠的に照射させて前記セラミック基板を切断することでできた端部にクラックを形成する、
    　請求項６に記載のセラミック基板の製造方法。     In the step of cutting the ceramic substrate, the edge formed by cutting the ceramic substrate by intermittently irradiating the laser light while scanning the laser light source over the entire circumference of the entire peripheral edge side of the ceramic substrate. Form a crack in the part,
    The method for manufacturing a ceramic substrate according to claim 6.
  8. 　前記焼結工程では、前記焼成室内の冷却時に前記焼成室内の温度が６５０℃以下の温度になった場合に前記焼成室内の温度を急冷する、
    　請求項６又は７に記載のセラミック基板の製造方法。     In the sintering step, when the temperature in the firing chamber becomes 650 ° C. or lower when the firing chamber is cooled, the temperature in the firing chamber is rapidly cooled.
    The method for manufacturing a ceramic substrate according to claim 6 or 7.
  9. 　前記セラミック粉末は、窒化珪素粉末又は窒化アルミニウム粉末を含む、
    　請求項６～８のいずれか１項に記載のセラミック基板の製造方法。     The ceramic powder contains silicon nitride powder or aluminum nitride powder.
    The method for manufacturing a ceramic substrate according to any one of claims 6 to 8.
  10. 　請求項６～９のいずれか１項に記載のセラミック基板の製造方法と、
    　前記セラミック基板の表面側に第１金属層を固定し、裏面側に第２金属層を固定する固定工程と、
    　を含む、
    　複合基板の製造方法。     The method for manufacturing a ceramic substrate according to any one of claims 6 to 9.
    A fixing step of fixing the first metal layer on the front surface side of the ceramic substrate and fixing the second metal layer on the back surface side,
    including,
    Manufacturing method of composite substrate.
  11. 　請求項１０に記載の複合基板の製造方法と、
    　前記第１金属層及び前記第２金属層のいずれか一方に、少なくとも１つの回路パターンを形成するパターン形成工程と、
    　を含む、
    　回路基板の製造方法。     The method for manufacturing a composite substrate according to claim 10,
    A pattern forming step of forming at least one circuit pattern on either the first metal layer and the second metal layer,
    including,
    How to manufacture a circuit board.
  12. 　請求項１０に記載の複合基板の製造方法と、
    　前記第１金属層及び前記第２金属層のいずれか一方に、複数の回路パターンを形成するパターン形成工程と、
    　前記複数の回路パターンが形成された前記複合基板を、それぞれが１つの前記回路パターンを備える複数の回路基板に分割する分割工程と、
    　を含む、
    　複数の回路基板の製造方法。     The method for manufacturing a composite substrate according to claim 10,
    A pattern forming step of forming a plurality of circuit patterns on either the first metal layer or the second metal layer, and
    A division step of dividing the composite substrate on which the plurality of circuit patterns are formed into a plurality of circuit boards each having one of the circuit patterns.
    including,
    Manufacturing method for multiple circuit boards.
PCT/JP2020/042422 2019-11-15 2020-11-13 Ceramic substrate, composite substrate, circuit board, ceramic substrate production method, composite substrate production method, circuit board production method, and method for producing multiple circuit boards WO2021095845A1 (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000044344A (en) * 1998-07-23 2000-02-15 Toshiba Lighting & Technology Corp Ceramic substrate, fixing heater and apparatus for fixing
JP2000286511A (en) * 1999-03-31 2000-10-13 Kyocera Corp Ceramic substrate for electronic component
JP2007081024A (en) * 2005-09-13 2007-03-29 Hitachi Metals Ltd Silicon nitride substrate, silicon nitride circuit board and method of manufacturing silicon nitride board
WO2013146789A1 (en) * 2012-03-26 2013-10-03 日立金属株式会社 Sintered silicon nitride substrate and process for producing same

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000044344A (en) * 1998-07-23 2000-02-15 Toshiba Lighting & Technology Corp Ceramic substrate, fixing heater and apparatus for fixing
JP2000286511A (en) * 1999-03-31 2000-10-13 Kyocera Corp Ceramic substrate for electronic component
JP2007081024A (en) * 2005-09-13 2007-03-29 Hitachi Metals Ltd Silicon nitride substrate, silicon nitride circuit board and method of manufacturing silicon nitride board
WO2013146789A1 (en) * 2012-03-26 2013-10-03 日立金属株式会社 Sintered silicon nitride substrate and process for producing same

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