WO2021200867A1 - Silicon nitride plate and method for producing same, composite substrate and method for producing same, and circuit board and method for producing same - Google Patents

Silicon nitride plate and method for producing same, composite substrate and method for producing same, and circuit board and method for producing same Download PDF

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Publication number
WO2021200867A1
WO2021200867A1 PCT/JP2021/013393 JP2021013393W WO2021200867A1 WO 2021200867 A1 WO2021200867 A1 WO 2021200867A1 JP 2021013393 W JP2021013393 W JP 2021013393W WO 2021200867 A1 WO2021200867 A1 WO 2021200867A1
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silicon nitride
nitride plate
oxygen
scribe line
manufacturing
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PCT/JP2021/013393
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French (fr)
Japanese (ja)
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晃正 湯浅
善幸 江嶋
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 JP2022512241A priority Critical patent/JPWO2021200867A1/ja
Publication of WO2021200867A1 publication Critical patent/WO2021200867A1/en

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    • 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
    • H05K3/00—Apparatus or processes for manufacturing printed circuits

Definitions

  • the present disclosure relates to a silicon nitride plate and its manufacturing method, a composite substrate and its manufacturing method, and a circuit board and its manufacturing method.
  • Insulating ceramic plates may be used for circuit boards mounted on electronic devices.
  • a method for manufacturing such a circuit board the following techniques as described in Patent Document 1 are known. That is, a carbon dioxide laser, a YAG laser, or the like is used to provide a scribe line on the surface of the ceramic plate, and then a metal layer is bonded to the surface to form a composite substrate. Then, the metal layer on the surface of the composite substrate is processed into a circuit pattern by etching. After that, the composite substrate is divided along the scribe line to manufacture a plurality of circuit boards.
  • the silicon nitride plate becomes a product or part through various processes such as joining with a metal plate and forming a circuit. With the further improvement of the performance of electronic devices, the required quality level is becoming higher and higher. Under such circumstances, there is a concern that foreign matter generated in the manufacturing process may cause not only deterioration of appearance but also deterioration of product performance.
  • the present disclosure provides a silicon nitride plate having excellent reliability while maintaining a good appearance and a method for manufacturing the same.
  • the present disclosure also provides a composite substrate having excellent reliability and a method for manufacturing the same while maintaining a good appearance.
  • the present disclosure also provides a highly reliable circuit board and a method for manufacturing the same while maintaining a good appearance.
  • the silicon nitride plate scribe line needs to have a certain depth so that the silicon nitride plate can be smoothly divided in the subsequent process.
  • a scribe line having a predetermined depth it is necessary to irradiate a laser beam having a corresponding energy.
  • the energy of the laser beam becomes excessive, the silicon nitride contained in the base material is scorched and foreign matter is generated inside the hole, which causes the silicon nitride plate to become dirty.
  • the present disclosure is a method for manufacturing a silicon nitride plate having a silicon nitride plate on its surface on one side, in which a plurality of holes are formed on the surface of a base material containing silicon nitride by laser light to provide a scribing line.
  • a method for manufacturing a silicon nitride plate which comprises a step and each of a plurality of holes is formed by irradiating a laser beam in a plurality of times.
  • each hole is formed by irradiating each hole with laser light in a plurality of times. Therefore, the energy of the laser beam irradiated per shot can be reduced as compared with the case where the hole is formed by only one irradiation. As a result, the laser beam can be efficiently used for forming the hole, and the scorching can be suppressed. Therefore, it is possible to suppress the formation of an oxygen-rich layer which is a foreign substance and maintain a good appearance of the silicon nitride plate. Such a silicon nitride plate is excellent in reliability because the oxygen-rich layer to be peeled off can be reduced. In addition, it is possible to suppress contamination of each manufacturing facility due to peeling and scattering of the oxygen-rich layer in the subsequent process.
  • the energy of the laser light per shot (one shot) when the laser light is irradiated in a plurality of times may be less than 15 mJ. As a result, the amount of oxygen-rich layer formed inside the hole can be sufficiently reduced.
  • the opening diameter of the hole on the surface of the silicon nitride plate obtained by the above manufacturing method may be 50 ⁇ m or more, and the depth of the hole may be 50 ⁇ m or more.
  • a silicon nitride plate having a scribe line composed of such holes can be smoothly divided.
  • the maximum thickness of the oxygen-rich layer at the bottom of the hole may be less than 8 ⁇ m.
  • the thickness of the oxygen-rich layer may be smaller on the surface than on the inner surface of the hole. As a result, dirt on the surface of the silicon nitride plate can be sufficiently suppressed and bondability can be improved.
  • the present disclosure provides a silicon nitride plate having a scribe line on its surface on one side, wherein the thickness of the oxygen-rich layer at the bottom of a plurality of holes constituting the scribe line is less than 8 ⁇ m. ..
  • the oxygen-rich layer which is a foreign substance, is sufficiently reduced. Therefore, the generation of dirt can be sufficiently suppressed and a good appearance can be maintained.
  • Such a silicon nitride plate is excellent in reliability because the oxygen-rich layer to be peeled off can be reduced. In addition, it is possible to reduce the contamination of each manufacturing facility due to the peeling and scattering of the oxygen-rich layer.
  • the present disclosure is a silicon nitride plate having a scribe line on the surface on one side, wherein the surface is smaller in thickness of the oxygen-rich layer than the inner surfaces of a plurality of holes constituting the scribe line. offer. Since the oxygen-rich layer on the surface of this silicon nitride plate is reduced, the generation of dirt can be sufficiently suppressed. Therefore, a good appearance can be maintained. In addition, the bondability with the member bonded to the surface of the silicon nitride plate can be improved. Therefore, it is also excellent in reliability. Further, since the oxygen-rich layer exposed on the surface can be reduced, it is possible to reduce the contamination of each manufacturing facility due to the peeling and scattering of the oxygen-rich layer. There may be no oxygen-rich layer on the surface.
  • the opening diameter of the hole on the surface may be 50 ⁇ m or more, and the depth of the hole may be 50 ⁇ m or more.
  • a silicon nitride plate having a scribe line composed of such holes can be smoothly divided.
  • the present disclosure comprises, in one aspect, a step of joining a metal plate to a silicon nitride plate so as to cover the surface of the silicon nitride plate obtained by any of the above-mentioned manufacturing methods to obtain a composite substrate.
  • Providing a manufacturing method for Since this composite substrate includes the silicon nitride plate obtained by any of the above-mentioned manufacturing methods, the oxygen-rich layer, which is a foreign substance, is reduced, and a good appearance can be maintained.
  • Such a composite substrate is also excellent in reliability because it can reduce the oxygen-rich layer peeling from the holes of the silicon nitride plate. In addition, it is possible to reduce the contamination of each manufacturing facility due to the peeling and scattering of the oxygen-rich layer.
  • a part of a metal plate in the composite substrate obtained by the above-mentioned manufacturing method is removed, and an independent conductor portion is formed for each section defined by a scribing line to form a circuit board.
  • a method for manufacturing a circuit board which comprises a step of obtaining. Since this circuit board uses the composite substrate obtained by the above-mentioned manufacturing method, the oxygen-rich layer, which is a foreign substance, is reduced, and a good appearance can be maintained. Such a circuit board is also excellent in reliability because it can reduce the oxygen-rich layer peeled from the holes of the silicon nitride plate. In addition, it is possible to reduce the contamination of each manufacturing facility due to the peeling and scattering of the oxygen-rich layer.
  • the present disclosure provides, on one side, a composite substrate comprising any of the above-mentioned silicon nitride plates and a metal plate bonded to the silicon nitride plate so as to cover the surface thereof. Since this composite substrate includes any of the above-mentioned silicon nitride plates, the oxygen-rich layer, which is a foreign substance, is reduced, and a good appearance can be maintained. Such a composite substrate is also excellent in reliability because it can reduce the oxygen-rich layer peeling from the holes of the silicon nitride plate. In addition, it is possible to reduce the contamination of each manufacturing facility due to the peeling and scattering of the oxygen-rich layer.
  • the present disclosure provides, on one side, a circuit board comprising any of the silicon nitride plates described above and a conductor portion provided on the surface of each compartment defined by a scribe line so as to be independent. Since this circuit board includes any of the above-mentioned silicon nitride plates, foreign matter is reduced and a good appearance can be maintained. Such a circuit board is also excellent in reliability because it can reduce the oxygen-rich layer peeled from the holes of the silicon nitride plate. In addition, it is possible to reduce the contamination of each manufacturing facility due to the peeling and scattering of the oxygen-rich layer.
  • a silicon nitride plate having excellent reliability and a method for manufacturing the same while maintaining a good appearance. Further, it is possible to provide a composite substrate having excellent reliability and a method for manufacturing the same while maintaining a good appearance. Further, it is possible to provide a circuit board having excellent reliability and a method for manufacturing the same while maintaining a good appearance.
  • FIG. 1 is a perspective view of a silicon nitride plate according to an embodiment.
  • FIG. 2 is a cross-sectional view taken along the line II-II of the silicon nitride plate of FIG.
  • FIG. 3 is a cross-sectional view taken along the line III-III of the silicon nitride plate of FIG.
  • FIG. 4 is a partially enlarged view showing an enlarged scribe line provided on a part of the surface of the silicon nitride plate.
  • FIG. 5 is a sectional view taken along line VV of the silicon nitride plate of FIG.
  • FIG. 6 is an enlarged cross-sectional view showing a cross section of a portion of the silicon nitride plate in which a hole is formed.
  • FIG. 1 is a perspective view of a silicon nitride plate according to an embodiment.
  • FIG. 2 is a cross-sectional view taken along the line II-II of the silicon nitride plate of FIG.
  • FIG. 7 is a perspective view showing an example of a silicon nitride plate coated with a brazing material.
  • FIG. 8 is a perspective view of the composite substrate according to the embodiment.
  • FIG. 9 is a perspective view showing an example of a composite substrate having a resist pattern formed on its surface.
  • FIG. 10 is a perspective view of the circuit board according to the embodiment.
  • FIG. 11 is an SEM photograph of the surface and cross section of the silicon nitride plate of Example 1 in which a plurality of holes constituting the scribe line are formed.
  • FIG. 12 is an SEM photograph of the surface and cross section of the silicon nitride plate of Comparative Example 1 in which a plurality of holes constituting the scribe line are formed.
  • FIG. 11 is an SEM photograph of the surface and cross section of the silicon nitride plate of Comparative Example 1 in which a plurality of holes constituting the scribe line are formed.
  • FIG. 13 is an SEM photograph taken by magnifying the cross section of the silicon nitride plate having holes formed at 250 times and 500 times.
  • FIG. 14 is an SEM photograph taken by magnifying the cross section of the silicon nitride plate having holes formed at 1000 times and 2500 times.
  • FIG. 1 is a perspective view of a silicon nitride plate according to an embodiment.
  • the silicon nitride plate 100 of FIG. 1 has a flat plate shape.
  • the surface 100A of the silicon nitride plate 100 is divided into a plurality of parts by a scribe line.
  • a plurality of scribe lines L1 extending along the first direction and arranging at equal intervals
  • a plurality of scribe lines L1 extending along the second direction orthogonal to the first direction and arranging at equal intervals.
  • the scribe line L2 is provided.
  • the scribe line L1 and the scribe line L2 are orthogonal to each other.
  • the scribe lines L1 and L2 are composed of a plurality of holes formed by laser light.
  • the laser source include a carbon dioxide laser and a YAG laser.
  • a scribe line can be provided by forming a plurality of holes along a predetermined direction by intermittently irradiating a laser beam from such a laser source.
  • the scribe lines L1 and L2 do not have to be arranged at equal intervals, and are not limited to orthogonal lines. Further, it may be curved or bent instead of straight.
  • FIG. 2 is a sectional view taken along line II-II of FIG. 1
  • FIG. 3 is a sectional view taken along line III-III of FIG.
  • the compartment 10 includes a region of one surface 100A surrounded by scribe lines L1 and L2, a region of the other surface 100B corresponding to the region, and a scribe line L1.
  • L2 is composed of three-dimensional regions surrounded by virtual lines VL1 and VL2 drawn parallel to the thickness direction of the silicon nitride plate 100. That is, the silicon nitride plate 100 has a plurality of compartments 10 (9 in FIG. 1) defined by the scribe line L1 and the scribe line L2.
  • FIGS. 1, 2 and 3 show an example in which the scribe lines L1 and L2 are formed only on the surface 100A on one side of the silicon nitride plate 100, but the present invention is not limited to this. That is, the scribe lines L1 and L2 may also be formed on the surface 100B opposite to the surface 100A of the silicon nitride plate 100.
  • FIG. 4 is a partially enlarged view showing an enlarged view of the scribe line L1 provided on a part of the surface 100A of the silicon nitride plate 100.
  • the scribe line L1 (L2) is composed of a plurality of holes 20 arranged along the longitudinal direction thereof. The holes 20 adjacent to each other may be connected or separated from each other.
  • the opening 20E of the hole 20 on the surface 100A may be circular.
  • the diameter of the opening 20E that is, the opening diameter r may be 50 ⁇ m or more, or 70 ⁇ m or more.
  • the silicon nitride plate 100 having the scribe line L1 (L2) composed of the holes 20 having such an opening diameter r can be smoothly divided along the scribe line L1 (L2).
  • the opening diameter r may be 300 ⁇ m or less, or 200 ⁇ m or less, from the viewpoint of maintaining the mechanical strength of the silicon nitride plate 100.
  • the adjacent holes 20 may be separated from each other. In another modification, the adjacent holes 20 may partially overlap each other.
  • FIG. 5 is a sectional view taken along line VV of FIG. That is, FIG. 5 is a cross-sectional view of the silicon nitride plate 100 when it is cut along a plane perpendicular to the surface 100A through the scribe line L1 (L2).
  • the hole 20 has a mortar shape that tapers from the opening 20E toward the inside of the silicon nitride plate 100.
  • the hole 20 has a depth d from the opening 20E to the bottom 20B on the surface 100A.
  • the depth d may be 50 ⁇ m or more, and may be 60 ⁇ m or more.
  • the silicon nitride plate 100 having the scribe line L1 (L2) composed of the holes 20 having such a depth d can be smoothly divided along the scribe line L1 (L2).
  • the depth d may be less than half or less than one-third of the thickness of the silicon nitride plate 100 from the viewpoint of maintaining the mechanical strength of the silicon nitride plate 100.
  • the depth d of the plurality of holes 20 may be the same or different.
  • FIG. 6 is a cross-sectional view showing a cross section of a portion of the silicon nitride plate in which the hole 20 is formed, which is further enlarged than in FIG.
  • at least a part of the inner surface of the mortar-shaped hole 20 may be covered with the oxygen-rich layer 22.
  • the oxygen-rich layer 22 is not substantially formed on the surface 100A, and the thickness of the oxygen-rich layer 22 on the surface 100A is smaller than that on the inner surface of the hole 20. Thereby, the generation of dirt caused by the oxygen-rich layer 22 can be sufficiently suppressed.
  • the bondability with the member bonded to the surface 100A can be improved.
  • the maximum thickness t of the oxygen-rich layer 22 at the bottom 20B of the hole 20 may be less than 8 ⁇ m, less than 6 ⁇ m, or less than 5 ⁇ m.
  • the oxygen-rich layer 22 is a region in which the mass-based oxygen concentration is three times or more the surface 100A of the silicon nitride plate 100 in the portion where the scribe lines L1 and L2 are not formed.
  • the oxygen concentration can be measured by EPMA (Electron Microanalyzer).
  • the oxygen-rich layer 22 is composed of a foreign substance different from silicon nitride.
  • the oxygen-rich layer 22 may contain, for example, an oxide.
  • the oxide may be, for example, silicon dioxide.
  • the thickness of the oxygen-rich layer 22 is usually the largest at the bottom 20B of the hole 20. Therefore, by reducing the maximum thickness t, the oxygen-rich layer 22 is reduced, and dirt due to peeling of the oxygen-rich layer 22 can be suppressed.
  • Such a silicon nitride plate 100 can suppress a decrease in reliability due to peeling of the oxygen-rich layer 22.
  • contamination by the oxygen-rich layer 22 of each manufacturing facility can be reduced.
  • the maximum thickness t is measured along the direction perpendicular to the surface 100A.
  • FIG. 6 shows an example in which the entire inner surface of the hole 20 is covered with the oxygen-rich layer 22, but the present invention is not limited to such an example.
  • the present invention is not limited to such an example.
  • only a part of the inner surface of the hole 20 may be covered with the oxygen-rich layer 22, or the inner surface of the hole 20 may not be covered with the oxygen-rich layer 22 at all. In this case, it is possible to prevent the generation of dirt due to foreign matter.
  • Such a silicon nitride plate 100 has sufficiently excellent reliability.
  • the method for manufacturing the silicon nitride plate 100 includes a step of producing a base material containing silicon nitride and a step of forming a plurality of holes on the surface of the base material with a laser beam and providing a scribing line to obtain the silicon nitride plate 100.
  • the base material containing silicon nitride can be produced by the following procedure. First, a slurry containing silicon nitride powder, a binder resin, a sintering aid, a plasticizer, a dispersant, a solvent and the like is molded to obtain a green sheet.
  • the sintering aid include rare earth metals, alkaline earth metals, metal oxides, fluorides, chlorides, nitrates, sulfates and the like. These may be used alone or in combination of two or more. By using the sintering aid, the sintering of the inorganic compound powder can be promoted.
  • the binder resin include methyl cellulose, ethyl cellulose, polyvinyl alcohol, polyvinyl butyral, and (meth) acrylic resins.
  • plasticizers include phthalate-based plasticizers such as purified glycerin, glycerin triolate, diethylene glycol, and di-n-butylphthalate, and dibasic acid-based plasticizers such as di-2-ethylhexyl sebacate.
  • dispersants include poly (meth) acrylate and (meth) acrylic acid-maleate copolymers.
  • solvent include organic solvents such as ethanol and toluene.
  • Examples of the slurry molding method include a doctor blade method and an extrusion molding method.
  • a green sheet is produced by such a method.
  • the green sheet is degreased and sintered to obtain a base material containing silicon nitride.
  • Solventing may be carried out by heating at, for example, 400 to 800 ° C. for 0.5 to 20 hours.
  • Sintering may be carried out by heating to 1700 to 1900 ° C. in an atmosphere of a non-oxidizing gas such as nitrogen, argon, ammonia or hydrogen.
  • the above-mentioned degreasing and sintering may be performed in a state where a plurality of green sheets are laminated.
  • a release layer using a release agent may be provided between the green sheets in order to facilitate separation of the base material after firing.
  • the release agent for example, boron nitride (BN) can be used.
  • the release layer may be formed by applying, for example, a slurry of boron nitride powder by a method such as spraying, brushing, roll coating, or screen printing.
  • the number of green sheets to be laminated may be, for example, 8 to 100 sheets or 30 to 70 sheets from the viewpoint of sufficiently advancing degreasing while efficiently mass-producing the base material.
  • the surface of the base material containing silicon nitride thus obtained is irradiated with laser light to form a plurality of holes.
  • a silicon nitride plate 100 having scribe lines L1 and L2 on the surface 100A as shown in FIGS. 1 to 3 is obtained.
  • the laser light include a carbon dioxide gas laser and a YAG laser.
  • Each of the plurality of holes 20 shown in FIGS. 4 and 5 is formed by irradiating the laser beam in a plurality of times. As a result, the energy of the laser beam irradiated per shot can be reduced as compared with the case where the hole is formed by only one irradiation.
  • the laser beam can be efficiently used for forming the hole 20, and the scorching of silicon nitride can be suppressed.
  • the generation of the oxygen-rich layer 22 shown in FIG. 6 can be suppressed, and the good appearance of the silicon nitride plate can be maintained.
  • Such a silicon nitride plate 100 is excellent in reliability because the oxygen-rich layer 22 to be peeled off can be reduced. Further, it is possible to reduce the contamination of the silicon nitride plate 100 and the manufacturing equipment using the silicon nitride plate 100.
  • the hole 20 may be formed by the burst pulse mode or the cycle pulse mode.
  • the burst pulse mode is performed according to the following procedure.
  • the first hole 20 is formed by irradiating the same position with the laser beam in a plurality of times.
  • the laser beam is irradiated in a plurality of times so as to be adjacent to the first hole 20 to form the second hole 20.
  • This forms two holes 20 adjacent to each other.
  • Such a procedure is repeated a plurality of times to form n holes 20 (n is a positive integer of 2 or more).
  • the scribe line L1 (L2) composed of n holes 20 can be formed.
  • the cycle pulse mode is performed by the following procedure, for example.
  • the first to nth holes 20 are formed by irradiating each laser beam once. After that, the first to nth holes 20 are irradiated with the laser beam once again. In this case as well, the laser beam is irradiated in 2n times in order to form the n holes 20.
  • the laser beam may be irradiated three times or more to form each hole 20. From the viewpoint of work efficiency, the number of times (the number of shots) of irradiating the laser beam for forming each hole 20 may be 10 times or less.
  • the method of forming the hole 20 is not limited to the above two methods. For example, a burst pulse mode and a cycle pulse mode may be combined.
  • the irradiation interval of the multiple laser beams irradiated to form one hole 20 is 100 ⁇ sec or more (10 kHz or less) in order to secure the cooling time of the silicon nitride plate 100 heated by the irradiation of the laser light. It may be 1000 ⁇ sec or more (1 kHz or less).
  • the energy of the laser beam irradiated per shot may be less than 15 mJ, 12 mJ or less, or 10 mJ or less.
  • the energy of the laser beam irradiated at one time may be 2 mJ or more, and may be 4 mJ or more.
  • the pulse width of the laser beam may be 3 to 20 ⁇ sec from the viewpoint of reducing damage to the silicon nitride plate 100 while forming a hole 20 having a sufficient size on the surface 100A of the silicon nitride plate 100. It may be up to 15 ⁇ s.
  • the scribe lines L1 and L2 serve as cutting lines when the silicon nitride plate 100 (circuit board) is divided in a subsequent process.
  • the holes 20 constituting the scribe line L1 (L2) are each formed by irradiating a laser beam a plurality of times. Therefore, the energy of the laser beam irradiated per shot can be reduced as compared with the case where the hole is formed by only one irradiation. As a result, foreign matter (oxygen-rich layer 22) generated on the inner surface of the hole 20 can be reduced, and a good appearance of the silicon nitride plate 100 can be maintained. Since such a silicon nitride plate 100 can reduce the oxygen-rich layer 22, it is also excellent in reliability. In addition, it is possible to suppress contamination of each manufacturing facility due to peeling and scattering of the oxygen-rich layer 22 in the subsequent process.
  • the silicon nitride plate 100 described above is used as the method for manufacturing the composite substrate according to the embodiment. That is, this manufacturing method includes a step of laminating a pair of metal plates so as to cover the surface 100A and the surface 100B of the silicon nitride plate 100, and joining the pair of metal plates to the silicon nitride plate 100 to obtain a composite substrate. ..
  • the metal plate may have a flat plate shape similar to that of the silicon nitride plate 100.
  • the pair of metal plates are joined to the surface 100A and the surface 100B of the silicon nitride plate 100, respectively, via a brazing material.
  • a paste-like brazing material is applied to the pair of surfaces 100A and 100B of the silicon nitride plate 100 by a method such as a roll coater method, a screen printing method, or a transfer method.
  • the brazing material contains, for example, metal components such as silver and titanium, an organic solvent, a binder and the like.
  • the viscosity of the brazing filler metal may be, for example, 5 to 20 Pa ⁇ s.
  • the content of the organic solvent in the brazing material may be, for example, 5 to 25% by mass, and the content of the binder amount may be, for example, 2 to 15% by mass.
  • FIG. 7 is a perspective view showing an example of the silicon nitride plate 100 coated with the brazing material 40. As shown in FIG. 7, the brazing filler metal 40 may be applied independently for each section 10. Although FIG. 7 shows only the surface 100A side, the brazing material 40 may be similarly coated on the surface 100B side as well. In the modified example, the brazing material may be applied to the entire surfaces of the surface 100A and the surface 100B.
  • a metal plate is attached to the surface 100A and the surface 100B of the silicon nitride plate 100 coated with the brazing material 40 to obtain a bonded body. Then, it is heated in a heating furnace to sufficiently join the silicon nitride plate 100 and the pair of metal plates to obtain a composite substrate.
  • the heating temperature may be, for example, 700 to 900 ° C.
  • the atmosphere in the heating furnace may be an inert gas such as nitrogen, and may be carried out under reduced pressure below atmospheric pressure or under vacuum.
  • the heating furnace may be a continuous type that continuously manufactures a plurality of joints, or may be a batch type that manufactures one or a plurality of joints. The heating may be performed while pressing the bonded body in the stacking direction.
  • the oxygen-rich layer 22 on the inner surface of the holes 20 constituting the scribe lines L1 and L2 is reduced in the silicon nitride plate 100, a composite substrate having a good appearance can be obtained. Further, since the scattering of the oxygen-rich layer is suppressed during firing, contamination inside the heating furnace can be reduced. Further, since the oxygen-rich layer 22 to be peeled off can be reduced, the bondability between the metal plate and the silicon nitride plate 100 can be improved.
  • FIG. 8 is a perspective view of the composite substrate according to the embodiment.
  • the composite substrate 200 includes a pair of metal plates 110 arranged so as to face each other, and a silicon nitride plate 100 between the pair of metal plates 110.
  • the pair of metal plates 110 are joined to the silicon nitride plate 100 so as to cover the surface 100A and the surface 100B of the silicon nitride plate 100.
  • Examples of the metal plate 110 include a copper plate.
  • the shape and size of the silicon nitride plate 100 and the metal plate 110 may be the same or different.
  • the composite substrate 200 can be manufactured by the above-mentioned manufacturing method. Since the oxygen-rich layer 22 formed in the hole 20 of the silicon nitride plate 100 is reduced, a good appearance can be maintained. Such a composite substrate 200 is excellent in reliability because the oxygen-rich layer 22 is reduced. Further, it is possible to reduce the contamination of the composite substrate 200 and each manufacturing facility using the composite substrate 200.
  • the circuit board manufacturing method is a step of removing a part of the metal plate in the composite substrate to form an independent conductor portion for each section, following the above-mentioned composite substrate manufacturing method.
  • This step may be performed, for example, by photolithography. Specifically, first, a photosensitive resist is printed on the surface of the composite substrate. Then, a resist pattern having a predetermined shape is formed by using an exposure apparatus. The resist may be a negative type or a positive type. The uncured resist is removed, for example, by washing.
  • FIG. 9 is a perspective view showing an example of the composite substrate 200 in which the resist pattern 30 is formed on the surface 200A. Although FIG. 9 shows only the surface 200A side, a similar resist pattern may be formed on the surface 200B side as well.
  • the resist pattern 30 is formed on the surface 200A and the surface 200B in a region corresponding to each section 10 of the silicon nitride plate 100.
  • the portion of the metal plate 110 that is not covered by the resist pattern 30 is removed by etching. As a result, the surface 100A and the surface 100B of the silicon nitride plate 100 are exposed in the portion. After that, the resist pattern 30 is removed to form an independent conductor portion for each compartment 10.
  • a circuit board is obtained by the above steps.
  • the oxygen-rich layer 22 on the inner surface of the holes 20 constituting the scribe lines L1 and L2 is reduced in the silicon nitride plate 100, a circuit board having a good appearance can be obtained. Further, since the oxygen-rich layer 22 to be peeled off can be reduced, contamination inside the exposure apparatus and the like can be suppressed. Further, the bondability between the conductor portion and the silicon nitride plate 100 can be improved.
  • FIG. 10 is a plan view of the circuit board according to the embodiment.
  • the circuit board 300 includes a silicon nitride plate 100 and conductor portions 50 arranged so as to face each other with the silicon nitride plate 100 interposed therebetween.
  • the conductor portion 50 is independently provided on the surface 100A and the surface 100B for each compartment 10. That is, each section 10 is provided with a pair of conductors 50 arranged so as to face each other.
  • the circuit board 300 is cut along the scribe lines L1 and L2 and divided into a plurality of divided boards.
  • the divided substrate is used as a component of, for example, a power module.
  • electronic components are mounted on the conductor portion 50 of the divided substrate.
  • the circuit board 300 can be manufactured by the above-mentioned manufacturing method. In the above-mentioned manufacturing method, since the silicon nitride plate 100 in which the oxygen-rich layer 22 on the inner surface of the hole 20 is reduced is used, the circuit board 300 and its divided substrate can maintain a good appearance. When the divided substrate is produced, the inner surface of the holes 20 forming the scribe lines L1 and L2 is exposed to the outer edge portion.
  • the silicon nitride plate 100 in which the oxygen-rich layer 22 on the inner surface of the hole 20 is reduced not only the divided substrate but also the power module on which the divided substrate is mounted can maintain a good appearance. In addition, the reliability of the power module can be improved.
  • each compartment 10 does not have to be the same, and each compartment 10 may have a different shape.
  • the silicon nitride plate and the composite substrate may have a shape other than the quadrangular prism shape.
  • any surface treatment may be applied to the conductor portion 50 of the circuit board 300.
  • a part of the surface of the conductor portion 50 may be covered with a protective layer such as a solder resist, and the other portion of the surface of the conductor portion 50 may be plated.
  • Example 1 A silicon nitride plate having the same shape and material as that of Example 1 was prepared. A carbon dioxide laser processing machine was used to form a plurality of holes connected in one direction on the surface of the silicon nitride plate, and a scribe line was provided. Each hole was formed by irradiating the laser beam only once (number of shots: 1). The energy of the laser beam and the pulse width per shot are as shown in Table 1.
  • FIG. 11 shows an SEM photograph of the surface and cross section of the silicon nitride plate of Example 1 in which a plurality of holes constituting the scribe line are formed.
  • the SEM photograph A of FIG. 11 shows the surface of the silicon nitride plate of Example 1 in which a plurality of holes 20 are formed.
  • the SEM photograph B of FIG. 11 shows a cross section of the silicon nitride plate of Example 1 in which a plurality of holes 20 are formed. That is, the SEM photograph B shows a cross section of the silicon nitride plate when cut along a surface perpendicular to the surface provided with the scribe line and passing through the scribe line.
  • FIG. 12 shows an SEM photograph of the surface and cross section of the silicon nitride plate of Comparative Example 1 in which a plurality of holes constituting the scribe line are formed.
  • the SEM photograph A of FIG. 12 shows the surface of the silicon nitride plate of Comparative Example 1 in which a plurality of holes 20 are formed.
  • the SEM photograph B of FIG. 12 shows a cross section of the silicon nitride plate of Comparative Example 1 in which a plurality of holes 20 are formed. That is, the SEM photograph B shows a cross section of the silicon nitride plate when cut along a surface perpendicular to the surface provided with the scribe line and passing through the scribe line.
  • FIG. 13 is an SEM photograph taken by magnifying the cross section of the silicon nitride plate having holes formed in Example 1 and Comparative Example 1 at 250 times and 500 times.
  • FIG. 14 is an SEM photograph taken by magnifying the cross section of the silicon nitride plate having holes formed in Example 1 and Comparative Example 1 at 1000 times and 2500 times. 13 and 14 show a cross section of the silicon nitride plate when cut in a plane perpendicular to the surface on which the scribe line is formed and perpendicular to the longitudinal direction of the scribe line.
  • Example 1 the thickness of the oxygen-rich layer (oxygen concentration was the same as in Comparative Example 1) on the inner surface and bottom of the hole was thinner than that in Comparative Example 1.
  • the maximum thickness t of the oxygen-rich layer at the bottom of the hole was 3 ⁇ m. From this, it was confirmed that the oxygen-rich layer formed on the inner surface of the hole can be reduced by irradiating the laser beam in a plurality of times when forming the hole.
  • the thickness of the oxygen-rich layer formed at the bottom of the holes constituting the scribe line was significantly smaller than that of Comparative Example 1.
  • Such a silicon nitride plate can suppress stains due to peeling of the oxygen-rich layer and can maintain a good appearance. In addition, it is possible to suppress a decrease in reliability due to peeling of the oxygen-rich layer and reduce contamination of each manufacturing facility.
  • a silicon nitride plate having excellent reliability and a method for manufacturing the same while maintaining a good appearance. Further, it is possible to provide a composite substrate having excellent reliability and a method for manufacturing the same while maintaining a good appearance. Further, it is possible to provide a circuit board having excellent reliability and a method for manufacturing the same while maintaining a good appearance.
  • 10 partition, 20 ... hole, 20B ... bottom, 20E ... opening, 22 ... oxygen rich layer, 30 ... resist pattern, 40 ... brazing material, 100 ... silicon nitride plate, 100A, 100B ... surface, 110 ... metal plate , 200 ... Composite substrate, 200A, 200B ... Surface, 300 ... Circuit board, L1, L2 ... Scrivener line, VL1, VL2 ... Virtual line.

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Abstract

The present invention provides a method for producing a silicon nitride plate that has a scribe line in the surface, said method having a step for providing a scribe line by forming a plurality of holes, by means of laser light, in the surface of a base material that contains silicon nitride, wherein each one of the plurality of holes is formed by irradiation of laser light performed in a plurality of times. The present invention also provides a method for producing a composite substrate, said method having a step for obtaining a composite substrate by bonding a metal plate to a silicon nitride plate that is obtained by the above-described production method in such a manner that the surface of the silicon nitride plate is covered by the metal plate.

Description

窒化ケイ素板及びその製造方法、複合基板及びその製造方法、並びに、回路基板及びその製造方法Silicon nitride plate and its manufacturing method, composite substrate and its manufacturing method, and circuit board and its manufacturing method
　本開示は、窒化ケイ素板及びその製造方法、複合基板及びその製造方法、並びに、回路基板及びその製造方法に関する。 The present disclosure relates to a silicon nitride plate and its manufacturing method, a composite substrate and its manufacturing method, and a circuit board and its manufacturing method.
　電子デバイスに搭載される回路基板には、絶縁性のセラミックス板が用いられる場合がある。このような回路基板の製造方法としては、特許文献１に記載されるような以下の技術が知られている。すなわち、炭酸ガスレーザー又はＹＡＧレーザー等を用い、セラミックス板の表面にスクライブラインを設けた後、当該表面に金属層を接合して複合基板を形成する。そして、複合基板の表面の金属層をエッチングにより回路パターンに加工する。その後、スクライブラインに沿って複合基板を分割し複数の回路基板を製造する。 Insulating ceramic plates may be used for circuit boards mounted on electronic devices. As a method for manufacturing such a circuit board, the following techniques as described in Patent Document 1 are known. That is, a carbon dioxide laser, a YAG laser, or the like is used to provide a scribe line on the surface of the ceramic plate, and then a metal layer is bonded to the surface to form a composite substrate. Then, the metal layer on the surface of the composite substrate is processed into a circuit pattern by etching. After that, the composite substrate is divided along the scribe line to manufacture a plurality of circuit boards.
特開２００７－３２４３０１号公報JP-A-2007-324301
　窒化ケイ素板は、金属板との接合、及び回路の形成等、各種工程を経て製品又は部品となる。電子デバイスの更なる高性能化に伴い、要求される品質レベルも益々高くなりつつある。このような状況下、製造工程において発生する異物が、外観の悪化のみならず、製品性能の低下等の要因になることも懸念される。 The silicon nitride plate becomes a product or part through various processes such as joining with a metal plate and forming a circuit. With the further improvement of the performance of electronic devices, the required quality level is becoming higher and higher. Under such circumstances, there is a concern that foreign matter generated in the manufacturing process may cause not only deterioration of appearance but also deterioration of product performance.
　そこで、本開示は、良好な外観を維持しつつ、信頼性に優れる窒化ケイ素板及びその製造方法を提供する。また、本開示は、良好な外観を維持しつつ、信頼性に優れる複合基板及びその製造方法を提供する。また、本開示は、良好な外観を維持しつつ、信頼性に優れる回路基板及びその製造方法を提供する。 Therefore, the present disclosure provides a silicon nitride plate having excellent reliability while maintaining a good appearance and a method for manufacturing the same. The present disclosure also provides a composite substrate having excellent reliability and a method for manufacturing the same while maintaining a good appearance. The present disclosure also provides a highly reliable circuit board and a method for manufacturing the same while maintaining a good appearance.
　窒化ケイ素板のスクライブラインは、後工程において窒化ケイ素板を円滑に分割できるようにするため、ある程度の深さを有する必要がある。所定の深さを有するスクライブラインを形成するためには、相応のエネルギーを有するレーザー光を照射する必要がある。ところが、レーザー光のエネルギーが過大になると、基材に含まれる窒化ケイ素が焦げ付いて穴の内部に異物が生成し、これが窒化ケイ素板の汚れの要因となる。 The silicon nitride plate scribe line needs to have a certain depth so that the silicon nitride plate can be smoothly divided in the subsequent process. In order to form a scribe line having a predetermined depth, it is necessary to irradiate a laser beam having a corresponding energy. However, when the energy of the laser beam becomes excessive, the silicon nitride contained in the base material is scorched and foreign matter is generated inside the hole, which causes the silicon nitride plate to become dirty.
　そこで、本開示は、一つの側面において、表面にスクライブラインを有する窒化ケイ素板の製造方法であって、窒化ケイ素を含む基材の表面にレーザー光で複数の穴を形成してスクライブラインを設ける工程を有し、複数の穴のそれぞれは、レーザー光を複数回に分けて照射することによって形成される、窒化ケイ素板の製造方法を提供する。 Therefore, the present disclosure is a method for manufacturing a silicon nitride plate having a silicon nitride plate on its surface on one side, in which a plurality of holes are formed on the surface of a base material containing silicon nitride by laser light to provide a scribing line. Provided is a method for manufacturing a silicon nitride plate, which comprises a step and each of a plurality of holes is formed by irradiating a laser beam in a plurality of times.
　上記製造方法では、スクライブラインとなる複数の穴を形成する際に、それぞれの穴を、レーザー光を複数回に分けて照射して形成している。このため、１回のみの照射で穴を形成する場合に比べて、１回（１ショット）当たりに照射されるレーザー光のエネルギーを小さくすることができる。これによって、穴の形成にレーザー光を効率的に利用することが可能となり、焦げ付きを抑制することができる。したがって、異物である酸素リッチ層の生成を抑制し、窒化ケイ素板の良好な外観を維持することができる。このような窒化ケイ素板は、剥離する酸素リッチ層を低減できるため信頼性にも優れる。また、後工程において酸素リッチ層の剥離及び飛散による各製造設備の汚染を抑制することができる。 In the above manufacturing method, when forming a plurality of holes to be scribe lines, each hole is formed by irradiating each hole with laser light in a plurality of times. Therefore, the energy of the laser beam irradiated per shot can be reduced as compared with the case where the hole is formed by only one irradiation. As a result, the laser beam can be efficiently used for forming the hole, and the scorching can be suppressed. Therefore, it is possible to suppress the formation of an oxygen-rich layer which is a foreign substance and maintain a good appearance of the silicon nitride plate. Such a silicon nitride plate is excellent in reliability because the oxygen-rich layer to be peeled off can be reduced. In addition, it is possible to suppress contamination of each manufacturing facility due to peeling and scattering of the oxygen-rich layer in the subsequent process.
　レーザー光を複数回に分けて照射する際の１回（１ショット）当たりのレーザー光のエネルギーは１５ｍＪ未満であってよい。これによって、穴の内部に形成される酸素リッチ層の生成量を十分に低減することができる。 The energy of the laser light per shot (one shot) when the laser light is irradiated in a plurality of times may be less than 15 mJ. As a result, the amount of oxygen-rich layer formed inside the hole can be sufficiently reduced.
　上記製造方法で得られる窒化ケイ素板の表面における穴の開口径は５０μｍ以上であり、穴の深さは５０μｍ以上であってよい。このような穴で構成されるスクライブラインを有する窒化ケイ素板は、円滑に分割することができる。 The opening diameter of the hole on the surface of the silicon nitride plate obtained by the above manufacturing method may be 50 μm or more, and the depth of the hole may be 50 μm or more. A silicon nitride plate having a scribe line composed of such holes can be smoothly divided.
　上記穴の底部における酸素リッチ層の最大厚みは８μｍ未満であってよい。これによって異物である酸素リッチ層を十分に低減し、汚れの発生を十分に抑制することができる。 The maximum thickness of the oxygen-rich layer at the bottom of the hole may be less than 8 μm. As a result, the oxygen-rich layer, which is a foreign substance, can be sufficiently reduced, and the generation of dirt can be sufficiently suppressed.
　上記表面の方が上記穴の内面よりも酸素リッチ層の厚みが小さくてよい。これによって、窒化ケイ素板の表面の汚れを十分に抑制するとともに接合性を向上することができる。 The thickness of the oxygen-rich layer may be smaller on the surface than on the inner surface of the hole. As a result, dirt on the surface of the silicon nitride plate can be sufficiently suppressed and bondability can be improved.
　本開示は、一つの側面において、表面にスクライブラインを有する窒化ケイ素板であって、スクライブラインを構成する複数の穴の底部における酸素リッチ層の厚みが８μｍ未満である、窒化ケイ素板を提供する。この窒化ケイ素板は、異物である酸素リッチ層が十分に低減されている。このため、汚れの発生を十分に抑制し、良好な外観を維持することができる。このような窒化ケイ素板は、剥離する酸素リッチ層を低減できるため信頼性にも優れる。また、酸素リッチ層の剥離及び飛散に伴う各製造設備の汚染を低減することができる。 The present disclosure provides a silicon nitride plate having a scribe line on its surface on one side, wherein the thickness of the oxygen-rich layer at the bottom of a plurality of holes constituting the scribe line is less than 8 μm. .. In this silicon nitride plate, the oxygen-rich layer, which is a foreign substance, is sufficiently reduced. Therefore, the generation of dirt can be sufficiently suppressed and a good appearance can be maintained. Such a silicon nitride plate is excellent in reliability because the oxygen-rich layer to be peeled off can be reduced. In addition, it is possible to reduce the contamination of each manufacturing facility due to the peeling and scattering of the oxygen-rich layer.
　本開示は、一つの側面において、表面にスクライブラインを有する窒化ケイ素板であって、表面の方がスクライブラインを構成する複数の穴の内面よりも酸素リッチ層の厚みが小さい、窒化ケイ素板を提供する。この窒化ケイ素板は、表面における酸素リッチ層が低減されていることから汚れの発生を十分に抑制できる。したがって、良好な外観を維持することができる。また、窒化ケイ素板の表面に接合される部材との接合性を向上することができる。このため信頼性にも優れる。また、表面に露出する酸素リッチ層を低減できることから、酸素リッチ層の剥離及び飛散に伴う各製造設備の汚染を低減することができる。なお、表面に酸素リッチ層は全くなくてもよい。 The present disclosure is a silicon nitride plate having a scribe line on the surface on one side, wherein the surface is smaller in thickness of the oxygen-rich layer than the inner surfaces of a plurality of holes constituting the scribe line. offer. Since the oxygen-rich layer on the surface of this silicon nitride plate is reduced, the generation of dirt can be sufficiently suppressed. Therefore, a good appearance can be maintained. In addition, the bondability with the member bonded to the surface of the silicon nitride plate can be improved. Therefore, it is also excellent in reliability. Further, since the oxygen-rich layer exposed on the surface can be reduced, it is possible to reduce the contamination of each manufacturing facility due to the peeling and scattering of the oxygen-rich layer. There may be no oxygen-rich layer on the surface.
　上記表面における穴の開口径は５０μｍ以上であり、穴の深さは５０μｍ以上であってよい。このような穴で構成されるスクライブラインを有する窒化ケイ素板は、円滑に分割することができる。 The opening diameter of the hole on the surface may be 50 μm or more, and the depth of the hole may be 50 μm or more. A silicon nitride plate having a scribe line composed of such holes can be smoothly divided.
　本開示は、一つの側面において、上述のいずれかの製造方法で得られた窒化ケイ素板の表面を覆うようにして金属板を窒化ケイ素板に接合して複合基板を得る工程を有する、複合基板の製造方法を提供する。この複合基板は、上述のいずれかの製造方法で得られた窒化ケイ素板を備えることから、異物である酸素リッチ層が低減されており、良好な外観を維持することができる。このような複合基板は、窒化ケイ素板の穴から剥離する酸素リッチ層を低減できるため信頼性にも優れる。また、酸素リッチ層の剥離及び飛散に伴う各製造設備の汚染を低減することができる。 The present disclosure comprises, in one aspect, a step of joining a metal plate to a silicon nitride plate so as to cover the surface of the silicon nitride plate obtained by any of the above-mentioned manufacturing methods to obtain a composite substrate. Providing a manufacturing method for. Since this composite substrate includes the silicon nitride plate obtained by any of the above-mentioned manufacturing methods, the oxygen-rich layer, which is a foreign substance, is reduced, and a good appearance can be maintained. Such a composite substrate is also excellent in reliability because it can reduce the oxygen-rich layer peeling from the holes of the silicon nitride plate. In addition, it is possible to reduce the contamination of each manufacturing facility due to the peeling and scattering of the oxygen-rich layer.
　本開示は、一つの側面において、上述の製造方法で得られた複合基板における金属板の一部を除去し、スクライブラインで画定される区画部毎に独立する導体部を形成して回路基板を得る工程を有する、回路基板の製造方法を提供する。この回路基板は、上述の製造方法で得られた複合基板を用いていることから、異物である酸素リッチ層が低減されており、良好な外観を維持することができる。このような回路基板は、窒化ケイ素板の穴から剥離する酸素リッチ層を低減できるため信頼性にも優れる。また、酸素リッチ層の剥離及び飛散に伴う各製造設備の汚染を低減することができる。 In one aspect of the present disclosure, a part of a metal plate in the composite substrate obtained by the above-mentioned manufacturing method is removed, and an independent conductor portion is formed for each section defined by a scribing line to form a circuit board. Provided is a method for manufacturing a circuit board, which comprises a step of obtaining. Since this circuit board uses the composite substrate obtained by the above-mentioned manufacturing method, the oxygen-rich layer, which is a foreign substance, is reduced, and a good appearance can be maintained. Such a circuit board is also excellent in reliability because it can reduce the oxygen-rich layer peeled from the holes of the silicon nitride plate. In addition, it is possible to reduce the contamination of each manufacturing facility due to the peeling and scattering of the oxygen-rich layer.
　本開示は、一つの側面において、上述のいずれかの窒化ケイ素板と、その表面を覆うように窒化ケイ素板に接合される金属板と、を備える複合基板を提供する。この複合基板は、上述のいずれかの窒化ケイ素板を備えることから、異物である酸素リッチ層が低減されており、良好な外観を維持することができる。このような複合基板は、窒化ケイ素板の穴から剥離する酸素リッチ層を低減できるため信頼性にも優れる。また、酸素リッチ層の剥離及び飛散に伴う各製造設備の汚染を低減することができる。 The present disclosure provides, on one side, a composite substrate comprising any of the above-mentioned silicon nitride plates and a metal plate bonded to the silicon nitride plate so as to cover the surface thereof. Since this composite substrate includes any of the above-mentioned silicon nitride plates, the oxygen-rich layer, which is a foreign substance, is reduced, and a good appearance can be maintained. Such a composite substrate is also excellent in reliability because it can reduce the oxygen-rich layer peeling from the holes of the silicon nitride plate. In addition, it is possible to reduce the contamination of each manufacturing facility due to the peeling and scattering of the oxygen-rich layer.
　本開示は、一つの側面において、上述のいずれかの窒化ケイ素板と、スクライブラインで画定される区画部毎に独立するように表面上に設けられる導体部と、を備える回路基板を提供する。この回路基板は、上述のいずれかの窒化ケイ素板を備えることから、異物が低減されており、良好な外観を維持することができる。このような回路基板は、窒化ケイ素板の穴から剥離する酸素リッチ層を低減できるため信頼性にも優れる。また、酸素リッチ層の剥離及び飛散に伴う各製造設備の汚染を低減することができる。 The present disclosure provides, on one side, a circuit board comprising any of the silicon nitride plates described above and a conductor portion provided on the surface of each compartment defined by a scribe line so as to be independent. Since this circuit board includes any of the above-mentioned silicon nitride plates, foreign matter is reduced and a good appearance can be maintained. Such a circuit board is also excellent in reliability because it can reduce the oxygen-rich layer peeled from the holes of the silicon nitride plate. In addition, it is possible to reduce the contamination of each manufacturing facility due to the peeling and scattering of the oxygen-rich layer.
　本開示によれば、良好な外観を維持しつつ、信頼性に優れる窒化ケイ素板及びその製造方法を提供することができる。また、良好な外観を維持しつつ、信頼性に優れる複合基板及びその製造方法を提供することができる。また、良好な外観を維持しつつ、信頼性に優れる回路基板及びその製造方法を提供することができる。 According to the present disclosure, it is possible to provide a silicon nitride plate having excellent reliability and a method for manufacturing the same while maintaining a good appearance. Further, it is possible to provide a composite substrate having excellent reliability and a method for manufacturing the same while maintaining a good appearance. Further, it is possible to provide a circuit board having excellent reliability and a method for manufacturing the same while maintaining a good appearance.
図１は、一実施形態に係る窒化ケイ素板の斜視図である。FIG. 1 is a perspective view of a silicon nitride plate according to an embodiment. 図２は、図１の窒化ケイ素板のＩＩ－ＩＩ線断面図である。FIG. 2 is a cross-sectional view taken along the line II-II of the silicon nitride plate of FIG. 図３は、図１の窒化ケイ素板のＩＩＩ－ＩＩＩ線断面図である。FIG. 3 is a cross-sectional view taken along the line III-III of the silicon nitride plate of FIG. 図４は、窒化ケイ素板の表面の一部分に設けられたスクライブラインを拡大して示す部分拡大図である。FIG. 4 is a partially enlarged view showing an enlarged scribe line provided on a part of the surface of the silicon nitride plate. 図５は、図４の窒化ケイ素板のＶ－Ｖ線断面図である。FIG. 5 is a sectional view taken along line VV of the silicon nitride plate of FIG. 図６は、窒化ケイ素板の穴が形成された部分の断面を拡大して示す断面図である。FIG. 6 is an enlarged cross-sectional view showing a cross section of a portion of the silicon nitride plate in which a hole is formed. 図７は、ろう材が塗布された窒化ケイ素板の一例を示す斜視図である。FIG. 7 is a perspective view showing an example of a silicon nitride plate coated with a brazing material. 図８は、一実施形態に係る複合基板の斜視図である。FIG. 8 is a perspective view of the composite substrate according to the embodiment. 図９は、表面にレジストパターンが形成された複合基板の一例を示す斜視図である。FIG. 9 is a perspective view showing an example of a composite substrate having a resist pattern formed on its surface. 図１０は、一実施形態に係る回路基板の斜視図である。FIG. 10 is a perspective view of the circuit board according to the embodiment. 図１１は、スクライブラインを構成する複数の穴が形成された実施例１の窒化ケイ素板の表面及び断面のＳＥＭ写真である。FIG. 11 is an SEM photograph of the surface and cross section of the silicon nitride plate of Example 1 in which a plurality of holes constituting the scribe line are formed. 図１２は、スクライブラインを構成する複数の穴が形成された比較例１の窒化ケイ素板の表面及び断面のＳＥＭ写真である。FIG. 12 is an SEM photograph of the surface and cross section of the silicon nitride plate of Comparative Example 1 in which a plurality of holes constituting the scribe line are formed. 図１３は、穴が形成された窒化ケイ素板の断面を、２５０倍及び５００倍に拡大して撮影したＳＥＭ写真である。FIG. 13 is an SEM photograph taken by magnifying the cross section of the silicon nitride plate having holes formed at 250 times and 500 times. 図１４は、穴が形成された窒化ケイ素板の断面を、１０００倍及び２５００倍に拡大して撮影したＳＥＭ写真である。FIG. 14 is an SEM photograph taken by magnifying the cross section of the silicon nitride plate having holes formed at 1000 times and 2500 times.
　以下、場合により図面を参照して、本開示の一実施形態について説明する。ただし、以下の実施形態は、本開示を説明するための例示であり、本開示を以下の内容に限定する趣旨ではない。説明において、同一要素又は同一機能を有する要素には同一符号を用い、場合により重複する説明は省略する。また、上下左右等の位置関係は、特に断らない限り、図面に示す位置関係に基づくものとする。更に、各要素の寸法比率は図示の比率に限られるものではない。 Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings in some cases. However, the following embodiments are examples for explaining the present disclosure, and are not intended to limit the present disclosure to the following contents. In the description, the same reference numerals are used for the same elements or elements having the same function, and duplicate description may be omitted in some cases. In addition, the positional relationship such as up, down, left, and right shall be based on the positional relationship shown in the drawings unless otherwise specified. Further, the dimensional ratio of each element is not limited to the ratio shown in the figure.
　図１は、一実施形態に係る窒化ケイ素板の斜視図である。図１の窒化ケイ素板１００は、平板形状を有する。窒化ケイ素板１００の表面１００Ａは、スクライブラインによって複数に区画されている。表面１００Ａには、第１の方向に沿って延在し且つ等間隔で並ぶ複数のスクライブラインＬ１と、第１の方向に直交する第２の方向に沿って延在し且つ等間隔で並ぶ複数のスクライブラインＬ２と、が設けられている。スクライブラインＬ１とスクライブラインＬ２とは互いに直交している。 FIG. 1 is a perspective view of a silicon nitride plate according to an embodiment. The silicon nitride plate 100 of FIG. 1 has a flat plate shape. The surface 100A of the silicon nitride plate 100 is divided into a plurality of parts by a scribe line. On the surface 100A, a plurality of scribe lines L1 extending along the first direction and arranging at equal intervals, and a plurality of scribe lines L1 extending along the second direction orthogonal to the first direction and arranging at equal intervals. The scribe line L2 is provided. The scribe line L1 and the scribe line L2 are orthogonal to each other.
　スクライブラインＬ１，Ｌ２は、レーザー光によって形成される複数の穴で構成される。レーザー源としては、例えば、炭酸ガスレーザー及びＹＡＧレーザー等が挙げられる。このようなレーザー源からレーザー光を間欠的に照射することによって複数の穴を所定の方向に沿って形成することで、スクライブラインを設けることができる。なお、スクライブラインＬ１，Ｌ２は、等間隔で並んでいなくてもよく、また、直交するものに限定されない。また、直線状ではなく、曲線状であってもよいし、折れ曲がっていてもよい。 The scribe lines L1 and L2 are composed of a plurality of holes formed by laser light. Examples of the laser source include a carbon dioxide laser and a YAG laser. A scribe line can be provided by forming a plurality of holes along a predetermined direction by intermittently irradiating a laser beam from such a laser source. The scribe lines L1 and L2 do not have to be arranged at equal intervals, and are not limited to orthogonal lines. Further, it may be curved or bent instead of straight.
　図２は図１のＩＩ－ＩＩ線断面図であり、図３は図１のＩＩＩ－ＩＩＩ線断面図である。図１、図２及び図３に示すように、区画部１０は、スクライブラインＬ１，Ｌ２で囲まれる一方の表面１００Ａの領域と、当該領域に対応する他方の表面１００Ｂの領域と、スクライブラインＬ１，Ｌ２から窒化ケイ素板１００の厚さ方向に平行に描かれる仮想線ＶＬ１，ＶＬ２と、で囲まれる３次元の領域で構成される。すなわち、窒化ケイ素板１００は、スクライブラインＬ１及びスクライブラインＬ２によって画定される複数の区画部１０（図１では９個）を有する。 FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. 3 is a sectional view taken along line III-III of FIG. As shown in FIGS. 1, 2 and 3, the compartment 10 includes a region of one surface 100A surrounded by scribe lines L1 and L2, a region of the other surface 100B corresponding to the region, and a scribe line L1. , L2 is composed of three-dimensional regions surrounded by virtual lines VL1 and VL2 drawn parallel to the thickness direction of the silicon nitride plate 100. That is, the silicon nitride plate 100 has a plurality of compartments 10 (9 in FIG. 1) defined by the scribe line L1 and the scribe line L2.
　図１、図２及び図３では、スクライブラインＬ１，Ｌ２が窒化ケイ素板１００の一方側の表面１００Ａのみに形成されている例を示したが、これに限定されない。すなわち、スクライブラインＬ１，Ｌ２は、窒化ケイ素板１００の表面１００Ａとは反対側の表面１００Ｂにも形成されていてもよい。 FIGS. 1, 2 and 3 show an example in which the scribe lines L1 and L2 are formed only on the surface 100A on one side of the silicon nitride plate 100, but the present invention is not limited to this. That is, the scribe lines L1 and L2 may also be formed on the surface 100B opposite to the surface 100A of the silicon nitride plate 100.
　図４は、窒化ケイ素板１００の表面１００Ａの一部分に設けられたスクライブラインＬ１を拡大して示す部分拡大図である。スクライブラインＬ１（Ｌ２）は、その長手方向に沿って並ぶ複数の穴２０によって構成される。互いに隣り合う穴２０同士は繋がっていてもよいし、離れていてもよい。表面１００Ａにおける穴２０の開口部２０Ｅは円形であってよい。開口部２０Ｅの直径、すなわち開口径ｒは、５０μｍ以上であってよいし、７０μｍ以上であってもよい。このような開口径ｒを有する穴２０で構成されるスクライブラインＬ１（Ｌ２）を有する窒化ケイ素板１００は、スクライブラインＬ１（Ｌ２）に沿って円滑に分割することができる。開口径ｒは、窒化ケイ素板１００の機械的強度を維持する観点から、３００μｍ以下であってよく、２００μｍ以下であってもよい。なお、変形例では、隣り合う穴２０同士は離れていてもよい。別の変形例では、隣り合う穴２０同士は、その一部が重なっていてもよい。 FIG. 4 is a partially enlarged view showing an enlarged view of the scribe line L1 provided on a part of the surface 100A of the silicon nitride plate 100. The scribe line L1 (L2) is composed of a plurality of holes 20 arranged along the longitudinal direction thereof. The holes 20 adjacent to each other may be connected or separated from each other. The opening 20E of the hole 20 on the surface 100A may be circular. The diameter of the opening 20E, that is, the opening diameter r may be 50 μm or more, or 70 μm or more. The silicon nitride plate 100 having the scribe line L1 (L2) composed of the holes 20 having such an opening diameter r can be smoothly divided along the scribe line L1 (L2). The opening diameter r may be 300 μm or less, or 200 μm or less, from the viewpoint of maintaining the mechanical strength of the silicon nitride plate 100. In the modified example, the adjacent holes 20 may be separated from each other. In another modification, the adjacent holes 20 may partially overlap each other.
　図５は、図４のＶ－Ｖ線断面図である。すなわち、図５は、窒化ケイ素板１００を、スクライブラインＬ１（Ｌ２）を通り、表面１００Ａに垂直な面で切断したときの断面図である。穴２０は、開口部２０Ｅから窒化ケイ素板１００の内部に向かって先細りとなるすり鉢形状を呈している。穴２０は、表面１００Ａにおける開口部２０Ｅから底部２０Ｂまでの深さｄを有する。窒化ケイ素板１００の厚みが０．１５～１ｍｍのとき、深さｄは、５０μｍ以上であってよく、６０μｍ以上であってもよい。このような深さｄを有する穴２０で構成されるスクライブラインＬ１（Ｌ２）を有する窒化ケイ素板１００は、スクライブラインＬ１（Ｌ２）に沿って円滑に分割することができる。深さｄは、窒化ケイ素板１００の機械的強度を維持する観点から、窒化ケイ素板１００の厚みの半分以下であってよく、１／３以下であってもよい。複数の穴２０の深さｄは、同一であってもよく、異なっていてもよい。 FIG. 5 is a sectional view taken along line VV of FIG. That is, FIG. 5 is a cross-sectional view of the silicon nitride plate 100 when it is cut along a plane perpendicular to the surface 100A through the scribe line L1 (L2). The hole 20 has a mortar shape that tapers from the opening 20E toward the inside of the silicon nitride plate 100. The hole 20 has a depth d from the opening 20E to the bottom 20B on the surface 100A. When the thickness of the silicon nitride plate 100 is 0.15 to 1 mm, the depth d may be 50 μm or more, and may be 60 μm or more. The silicon nitride plate 100 having the scribe line L1 (L2) composed of the holes 20 having such a depth d can be smoothly divided along the scribe line L1 (L2). The depth d may be less than half or less than one-third of the thickness of the silicon nitride plate 100 from the viewpoint of maintaining the mechanical strength of the silicon nitride plate 100. The depth d of the plurality of holes 20 may be the same or different.
　図６は、窒化ケイ素板の穴２０が形成された部分の断面を図５よりもさらに拡大して示す断面図である。図６に示されるように、すり鉢状の穴２０の内面の少なくとも一部は酸素リッチ層２２で覆われていてよい。表面１００Ａには酸素リッチ層２２が実質的に形成されておらず、表面１００Ａの方が穴２０の内面よりも酸素リッチ層２２の厚みが小さくなっている。これによって、酸素リッチ層２２に起因する汚れの発生を十分に抑制することができる。また、表面１００Ａに接合される部材との接合性を向上することができる。 FIG. 6 is a cross-sectional view showing a cross section of a portion of the silicon nitride plate in which the hole 20 is formed, which is further enlarged than in FIG. As shown in FIG. 6, at least a part of the inner surface of the mortar-shaped hole 20 may be covered with the oxygen-rich layer 22. The oxygen-rich layer 22 is not substantially formed on the surface 100A, and the thickness of the oxygen-rich layer 22 on the surface 100A is smaller than that on the inner surface of the hole 20. Thereby, the generation of dirt caused by the oxygen-rich layer 22 can be sufficiently suppressed. In addition, the bondability with the member bonded to the surface 100A can be improved.
　穴２０の底部２０Ｂにおける酸素リッチ層２２の最大厚みｔは、８μｍ未満であってよく、６μｍ未満であってよく、５μｍ未満であってよい。酸素リッチ層２２は、スクライブラインＬ１，Ｌ２が形成されていない部分の窒化ケイ素板１００の表面１００Ａに対して、質量基準の酸素濃度が３倍以上の領域である。酸素濃度は、ＥＰＭＡ（電子線マイクロアナライザ）で測定することができる。 The maximum thickness t of the oxygen-rich layer 22 at the bottom 20B of the hole 20 may be less than 8 μm, less than 6 μm, or less than 5 μm. The oxygen-rich layer 22 is a region in which the mass-based oxygen concentration is three times or more the surface 100A of the silicon nitride plate 100 in the portion where the scribe lines L1 and L2 are not formed. The oxygen concentration can be measured by EPMA (Electron Microanalyzer).
　酸素リッチ層２２は、窒化ケイ素とは異なる異物で構成される。酸素リッチ層２２は、例えば酸化物を含有してよい。酸化物は、例えば二酸化ケイ素であってよい。また、酸素リッチ層２２の厚みは、通常、穴２０の底部２０Ｂで最も大きくなる。このため、最大厚みｔを小さくすることによって、酸素リッチ層２２が低減され、酸素リッチ層２２の剥離による汚れを抑制することができる。このような窒化ケイ素板１００は、酸素リッチ層２２の剥離に起因する信頼性の低下を抑制することができる。また、各製造設備の酸素リッチ層２２による汚染を低減することができる。なお、最大厚みｔは、表面１００Ａに垂直な方向に沿って測定される。 The oxygen-rich layer 22 is composed of a foreign substance different from silicon nitride. The oxygen-rich layer 22 may contain, for example, an oxide. The oxide may be, for example, silicon dioxide. Further, the thickness of the oxygen-rich layer 22 is usually the largest at the bottom 20B of the hole 20. Therefore, by reducing the maximum thickness t, the oxygen-rich layer 22 is reduced, and dirt due to peeling of the oxygen-rich layer 22 can be suppressed. Such a silicon nitride plate 100 can suppress a decrease in reliability due to peeling of the oxygen-rich layer 22. In addition, contamination by the oxygen-rich layer 22 of each manufacturing facility can be reduced. The maximum thickness t is measured along the direction perpendicular to the surface 100A.
　図６では、穴２０の内面全体が酸素リッチ層２２で覆われる例が示されているが、このような例に限定されない。例えば、穴２０の内面の一部のみが酸素リッチ層２２で覆われていてもよいし、穴２０の内面が酸素リッチ層２２で全く覆われていなくてもよい。この場合、異物による汚れの発生を防止することができる。このような窒化ケイ素板１００は、十分に優れた信頼性を有する。 FIG. 6 shows an example in which the entire inner surface of the hole 20 is covered with the oxygen-rich layer 22, but the present invention is not limited to such an example. For example, only a part of the inner surface of the hole 20 may be covered with the oxygen-rich layer 22, or the inner surface of the hole 20 may not be covered with the oxygen-rich layer 22 at all. In this case, it is possible to prevent the generation of dirt due to foreign matter. Such a silicon nitride plate 100 has sufficiently excellent reliability.
　一実施形態に係る窒化ケイ素板の製造方法として、窒化ケイ素板１００の製造方法を説明する。窒化ケイ素板１００の製造方法は、窒化ケイ素を含む基材を作製する工程と、基材の表面にレーザー光で複数の穴を形成してスクライブラインを設けて窒化ケイ素板１００を得る工程とを有する。 As a method for manufacturing the silicon nitride plate according to the embodiment, a method for manufacturing the silicon nitride plate 100 will be described. The method for manufacturing the silicon nitride plate 100 includes a step of producing a base material containing silicon nitride and a step of forming a plurality of holes on the surface of the base material with a laser beam and providing a scribing line to obtain the silicon nitride plate 100. Have.
　窒化ケイ素を含む基材は、以下の手順で製造することができる。まず、窒化ケイ素粉末、バインダ樹脂、焼結助剤、可塑剤、分散剤、及び溶媒等を含むスラリーを成形してグリーンシートを得る。焼結助剤としては、希土類金属、アルカリ土類金属、金属酸化物、フッ化物、塩化物、硝酸塩、及び硫酸塩等が挙げられる。これらは一種のみ用いてもよいし二種以上を併用してもよい。焼結助剤を用いることにより、無機化合物粉末の焼結を促進させることができる。バインダ樹脂の例としては、メチルセルロース、エチルセルロース、ポリビニルアルコール、ポリビニルブチラール、及び（メタ）アクリル系樹脂等が挙げられる。 The base material containing silicon nitride can be produced by the following procedure. First, a slurry containing silicon nitride powder, a binder resin, a sintering aid, a plasticizer, a dispersant, a solvent and the like is molded to obtain a green sheet. Examples of the sintering aid include rare earth metals, alkaline earth metals, metal oxides, fluorides, chlorides, nitrates, sulfates and the like. These may be used alone or in combination of two or more. By using the sintering aid, the sintering of the inorganic compound powder can be promoted. Examples of the binder resin include methyl cellulose, ethyl cellulose, polyvinyl alcohol, polyvinyl butyral, and (meth) acrylic resins.
　可塑剤の例としては、精製グリセリン、グリセリントリオレート、ジエチレングリコール、ジ－ｎ－ブチルフタレート等のフタル酸系可塑剤、セバシン酸ジ－２－エチルヘキシル等の二塩基酸系可塑剤等が挙げられる。分散剤の例としては、ポリ（メタ）アクリル酸塩、及び（メタ）アクリル酸－マレイン酸塩コポリマーが挙げられる。溶媒としては、エタノール及びトルエン等の有機溶媒が挙げられる。 Examples of plasticizers include phthalate-based plasticizers such as purified glycerin, glycerin triolate, diethylene glycol, and di-n-butylphthalate, and dibasic acid-based plasticizers such as di-2-ethylhexyl sebacate. Examples of dispersants include poly (meth) acrylate and (meth) acrylic acid-maleate copolymers. Examples of the solvent include organic solvents such as ethanol and toluene.
　スラリーの成形方法の例としては、ドクターブレード法及び押出成形法が挙げられる。このような方法によってグリーンシートを作製する。グリーンシートの脱脂及び焼結を行って、窒化ケイ素を含む基材が得られる。脱脂は、例えば、４００～８００℃で、０．５～２０時間加熱して行ってよい。これによって、窒化ケイ素の酸化及び劣化を抑制しつつ、有機物（炭素）の残留量を低減することができる。焼結は、窒素、アルゴン、アンモニア又は水素等の非酸化性ガス雰囲気下、１７００～１９００℃に加熱して行ってよい。 Examples of the slurry molding method include a doctor blade method and an extrusion molding method. A green sheet is produced by such a method. The green sheet is degreased and sintered to obtain a base material containing silicon nitride. Solventing may be carried out by heating at, for example, 400 to 800 ° C. for 0.5 to 20 hours. As a result, the residual amount of organic matter (carbon) can be reduced while suppressing the oxidation and deterioration of silicon nitride. Sintering may be carried out by heating to 1700 to 1900 ° C. in an atmosphere of a non-oxidizing gas such as nitrogen, argon, ammonia or hydrogen.
　上述の脱脂及び焼結は、グリーンシートを複数積層した状態で行ってもよい。積層して脱脂及び焼結を行う場合、焼成後の基材の分離を円滑にするため、グリーンシート間に離型剤による離型層を設けてよい。離型剤としては、例えば、窒化ホウ素（ＢＮ）を用いることができる。離型層は、例えば、窒化ホウ素の粉末のスラリーを、スプレー、ブラシ、ロールコート、又はスクリーン印刷等の方法により塗布して形成してよい。積層するグリーンシートの枚数は、基材の量産を効率的に行いつつ、脱脂を十分に進行させる観点から、例えば８～１００枚であってよく、３０～７０枚であってもよい。 The above-mentioned degreasing and sintering may be performed in a state where a plurality of green sheets are laminated. When laminating for degreasing and sintering, a release layer using a release agent may be provided between the green sheets in order to facilitate separation of the base material after firing. As the release agent, for example, boron nitride (BN) can be used. The release layer may be formed by applying, for example, a slurry of boron nitride powder by a method such as spraying, brushing, roll coating, or screen printing. The number of green sheets to be laminated may be, for example, 8 to 100 sheets or 30 to 70 sheets from the viewpoint of sufficiently advancing degreasing while efficiently mass-producing the base material.
　このようにして得られた窒化ケイ素を含む基材の表面に、レーザー光を照射して複数の穴を形成する。これによって、図１～図３に示すような、表面１００ＡにスクライブラインＬ１，Ｌ２を有する窒化ケイ素板１００を得る。レーザー光としては、例えば、炭酸ガスレーザー及びＹＡＧレーザー等が挙げられる。図４、図５に示される複数の穴２０のそれぞれは、レーザー光を複数回に分けて照射することによって形成される。これによって、１回のみの照射で穴を形成する場合に比べて、１回（１ショット）当たりに照射されるレーザー光のエネルギーを小さくすることができる。したがって、穴２０の形成にレーザー光を効率的に利用することが可能となり、窒化ケイ素の焦げ付きを抑制することができる。その結果、図６に示される酸素リッチ層２２の発生を抑制し、窒化ケイ素板の良好な外観を維持することができる。このような窒化ケイ素板１００は、剥離する酸素リッチ層２２を低減できることから、信頼性に優れる。また、窒化ケイ素板１００及びこれを用いる各製造設備の汚染を低減することができる。 The surface of the base material containing silicon nitride thus obtained is irradiated with laser light to form a plurality of holes. As a result, a silicon nitride plate 100 having scribe lines L1 and L2 on the surface 100A as shown in FIGS. 1 to 3 is obtained. Examples of the laser light include a carbon dioxide gas laser and a YAG laser. Each of the plurality of holes 20 shown in FIGS. 4 and 5 is formed by irradiating the laser beam in a plurality of times. As a result, the energy of the laser beam irradiated per shot can be reduced as compared with the case where the hole is formed by only one irradiation. Therefore, the laser beam can be efficiently used for forming the hole 20, and the scorching of silicon nitride can be suppressed. As a result, the generation of the oxygen-rich layer 22 shown in FIG. 6 can be suppressed, and the good appearance of the silicon nitride plate can be maintained. Such a silicon nitride plate 100 is excellent in reliability because the oxygen-rich layer 22 to be peeled off can be reduced. Further, it is possible to reduce the contamination of the silicon nitride plate 100 and the manufacturing equipment using the silicon nitride plate 100.
　穴２０は、バーストパルスモードによって形成してもよいし、サイクルパルスモードによって形成してもよい。バーストパルスモードは、以下の手順で行う。レーザー光を複数回に分けて同じ位置に照射して、一つ目の穴２０を形成する。続いて、一つ目の穴２０に隣り合うように、レーザー光を複数回に分けて照射して二つ目の穴２０を形成する。これによって、互いに隣り合う２つの穴２０を形成する。このような手順を複数回繰り返して行いｎ個の穴２０を形成する（ｎは２以上の正の整数）。このようにしてｎ個の穴２０で構成されるからなるスクライブラインＬ１（Ｌ２）を形成することができる。１個の穴２０を形成するために２回レーザー光を照射する場合、ｎ個の穴２０を形成するためにはレーザー光を２ｎ回に分けて照射することになる。 The hole 20 may be formed by the burst pulse mode or the cycle pulse mode. The burst pulse mode is performed according to the following procedure. The first hole 20 is formed by irradiating the same position with the laser beam in a plurality of times. Subsequently, the laser beam is irradiated in a plurality of times so as to be adjacent to the first hole 20 to form the second hole 20. This forms two holes 20 adjacent to each other. Such a procedure is repeated a plurality of times to form n holes 20 (n is a positive integer of 2 or more). In this way, the scribe line L1 (L2) composed of n holes 20 can be formed. When the laser beam is irradiated twice to form one hole 20, the laser beam is irradiated twice in order to form the n holes 20.
　サイクルパルスモードは、例えば以下の手順で行う。１番目からｎ番目までの穴２０を、それぞれ１回ずつのレーザー光の照射で形成する。その後、１番目からｎ番目までの穴２０に、再びレーザー光を１回ずつ照射する。この場合も、ｎ個の穴２０を形成するためにレーザー光を２ｎ回に分けて照射することになる。なお、各穴２０の形成のためにレーザー光を３回以上照射してもよい。作業効率の観点から、各穴２０の形成のためにレーザー光を照射する回数（ショット数）は１０回以下であってよい。穴２０の形成方法は上述の２つの方法に限定されない。例えば、バーストパルスモードとサイクルパルスモードを組み合わせてもよい。 The cycle pulse mode is performed by the following procedure, for example. The first to nth holes 20 are formed by irradiating each laser beam once. After that, the first to nth holes 20 are irradiated with the laser beam once again. In this case as well, the laser beam is irradiated in 2n times in order to form the n holes 20. The laser beam may be irradiated three times or more to form each hole 20. From the viewpoint of work efficiency, the number of times (the number of shots) of irradiating the laser beam for forming each hole 20 may be 10 times or less. The method of forming the hole 20 is not limited to the above two methods. For example, a burst pulse mode and a cycle pulse mode may be combined.
　一つの穴２０を形成するために照射される複数回のレーザー光の照射間隔は、レーザー光の照射によって加熱される窒化ケイ素板１００の冷却時間を確保するため、１００μ秒間以上（１０ｋＨｚ以下）であってよく、１０００μ秒間以上（１ｋＨｚ以下）であってよい。 The irradiation interval of the multiple laser beams irradiated to form one hole 20 is 100 μsec or more (10 kHz or less) in order to secure the cooling time of the silicon nitride plate 100 heated by the irradiation of the laser light. It may be 1000 μsec or more (1 kHz or less).
　１回当たりに照射されるレーザー光のエネルギー、すなわち１ショット当たりのエネルギーは、１５ｍＪ未満であってよく、１２ｍＪ以下であってよく、１０ｍＪ以下であってもよい。このように１回当たりに照射されるエネルギーを小さくすることによって、穴２０の内面に生成する酸素リッチ層２２の最大厚みｔを十分に小さくすることができる。なお、穴２０を効率よく形成する観点から、１回当たりに照射されるレーザー光のエネルギーは２ｍＪ以上であってよく、４ｍＪ以上であってもよい。 The energy of the laser beam irradiated per shot, that is, the energy per shot may be less than 15 mJ, 12 mJ or less, or 10 mJ or less. By reducing the energy irradiated each time in this way, the maximum thickness t of the oxygen-rich layer 22 generated on the inner surface of the hole 20 can be sufficiently reduced. From the viewpoint of efficiently forming the holes 20, the energy of the laser beam irradiated at one time may be 2 mJ or more, and may be 4 mJ or more.
　レーザー光のパルス幅は、窒化ケイ素板１００の表面１００Ａに十分な大きさの穴２０を形成しつつ、窒化ケイ素板１００へのダメージを低減する観点から、３～２０μ秒であってよく、５～１５μ秒であってもよい。 The pulse width of the laser beam may be 3 to 20 μsec from the viewpoint of reducing damage to the silicon nitride plate 100 while forming a hole 20 having a sufficient size on the surface 100A of the silicon nitride plate 100. It may be up to 15 μs.
　このようにして、スクライブラインＬ１，Ｌ２を設けることによって、窒化ケイ素板１００を得ることができる。スクライブラインＬ１，Ｌ２は、後工程において、窒化ケイ素板１００（回路基板）を分割する際の切断線となる。 By providing the scribe lines L1 and L2 in this way, the silicon nitride plate 100 can be obtained. The scribe lines L1 and L2 serve as cutting lines when the silicon nitride plate 100 (circuit board) is divided in a subsequent process.
　上述の窒化ケイ素板の製造方法では、スクライブラインＬ１（Ｌ２）を構成する穴２０は、それぞれ、レーザー光を複数回照射することによって形成される。このため、１回のみの照射で穴を形成する場合に比べて、１回（１ショット）当たりに照射されるレーザー光のエネルギーを小さくすることができる。これによって、穴２０の内面に生成する異物（酸素リッチ層２２）を低減し、窒化ケイ素板１００の良好な外観を維持することができる。このような窒化ケイ素板１００は、酸素リッチ層２２を低減できるため、信頼性にも優れる。また、後工程において酸素リッチ層２２の剥離及び飛散による各製造設備の汚染を抑制することができる。 In the above-mentioned method for manufacturing a silicon nitride plate, the holes 20 constituting the scribe line L1 (L2) are each formed by irradiating a laser beam a plurality of times. Therefore, the energy of the laser beam irradiated per shot can be reduced as compared with the case where the hole is formed by only one irradiation. As a result, foreign matter (oxygen-rich layer 22) generated on the inner surface of the hole 20 can be reduced, and a good appearance of the silicon nitride plate 100 can be maintained. Since such a silicon nitride plate 100 can reduce the oxygen-rich layer 22, it is also excellent in reliability. In addition, it is possible to suppress contamination of each manufacturing facility due to peeling and scattering of the oxygen-rich layer 22 in the subsequent process.
　一実施形態に係る複合基板の製造方法は、上述の窒化ケイ素板１００を用いる。すなわち、この製造方法は、窒化ケイ素板１００の表面１００Ａ及び表面１００Ｂをそれぞれ覆うように一対の金属板を積層し、一対の金属板を窒化ケイ素板１００に接合して複合基板を得る工程を有する。金属板は、窒化ケイ素板１００と同様の平板形状であってよい。一対の金属板は、ろう材を介して、窒化ケイ素板１００の表面１００Ａ及び表面１００Ｂにそれぞれ接合される。 The silicon nitride plate 100 described above is used as the method for manufacturing the composite substrate according to the embodiment. That is, this manufacturing method includes a step of laminating a pair of metal plates so as to cover the surface 100A and the surface 100B of the silicon nitride plate 100, and joining the pair of metal plates to the silicon nitride plate 100 to obtain a composite substrate. .. The metal plate may have a flat plate shape similar to that of the silicon nitride plate 100. The pair of metal plates are joined to the surface 100A and the surface 100B of the silicon nitride plate 100, respectively, via a brazing material.
　具体的には、まず、窒化ケイ素板１００の一対の表面１００Ａ，１００Ｂに、ロールコーター法、スクリーン印刷法、又は転写法等の方法によってペースト状のろう材を塗布する。ろう材は、例えば、銀及びチタン等の金属成分、有機溶媒、並びにバインダ等を含有する。ろう材の粘度は、例えば５～２０Ｐａ・ｓであってよい。ろう材における有機溶媒の含有量は、例えば、５～２５質量％、バインダ量の含有量は、例えば、２～１５質量％であってよい。 Specifically, first, a paste-like brazing material is applied to the pair of surfaces 100A and 100B of the silicon nitride plate 100 by a method such as a roll coater method, a screen printing method, or a transfer method. The brazing material contains, for example, metal components such as silver and titanium, an organic solvent, a binder and the like. The viscosity of the brazing filler metal may be, for example, 5 to 20 Pa · s. The content of the organic solvent in the brazing material may be, for example, 5 to 25% by mass, and the content of the binder amount may be, for example, 2 to 15% by mass.
　図７は、ろう材４０が塗布された窒化ケイ素板１００の一例を示す斜視図である。図７に示すように、ろう材４０は、区画部１０毎に独立して塗布されてよい。図７には、表面１００Ａ側のみを示しているが、表面１００Ｂ側にも同様にろう材４０が塗布されていてよい。変形例では、表面１００Ａと表面１００Ｂの全面にろう材を塗布してもよい。 FIG. 7 is a perspective view showing an example of the silicon nitride plate 100 coated with the brazing material 40. As shown in FIG. 7, the brazing filler metal 40 may be applied independently for each section 10. Although FIG. 7 shows only the surface 100A side, the brazing material 40 may be similarly coated on the surface 100B side as well. In the modified example, the brazing material may be applied to the entire surfaces of the surface 100A and the surface 100B.
　このようにして、ろう材４０が塗布された窒化ケイ素板１００の表面１００Ａ及び表面１００Ｂに、金属板を貼り合わせて接合体を得る。その後、加熱炉で加熱して窒化ケイ素板１００と一対の金属板とを十分に接合させて複合基板を得る。加熱温度は例えば７００～９００℃であってよい。加熱炉内の雰囲気は窒素等の不活性ガスであってよく、大気圧未満の減圧下で行ってもよいし、真空下で行ってもよい。加熱炉は、複数の接合体を連続的に製造する連続式のものであってもよく、一つ又は複数の接合体をバッチ式で製造するものであってもよい。加熱は、接合体を積層方向に押圧しながら行ってもよい。 In this way, a metal plate is attached to the surface 100A and the surface 100B of the silicon nitride plate 100 coated with the brazing material 40 to obtain a bonded body. Then, it is heated in a heating furnace to sufficiently join the silicon nitride plate 100 and the pair of metal plates to obtain a composite substrate. The heating temperature may be, for example, 700 to 900 ° C. The atmosphere in the heating furnace may be an inert gas such as nitrogen, and may be carried out under reduced pressure below atmospheric pressure or under vacuum. The heating furnace may be a continuous type that continuously manufactures a plurality of joints, or may be a batch type that manufactures one or a plurality of joints. The heating may be performed while pressing the bonded body in the stacking direction.
　窒化ケイ素板１００は、スクライブラインＬ１，Ｌ２を構成する穴２０の内面における酸素リッチ層２２が低減されているため、良好な外観を有する複合基板を得ることができる。また、焼成時に、酸素リッチ層の飛散が抑制されるため、加熱炉内部の汚染を低減することができる。また、剥離する酸素リッチ層２２を低減できることから、金属板と窒化ケイ素板１００との接合性を向上することができる。 Since the oxygen-rich layer 22 on the inner surface of the holes 20 constituting the scribe lines L1 and L2 is reduced in the silicon nitride plate 100, a composite substrate having a good appearance can be obtained. Further, since the scattering of the oxygen-rich layer is suppressed during firing, contamination inside the heating furnace can be reduced. Further, since the oxygen-rich layer 22 to be peeled off can be reduced, the bondability between the metal plate and the silicon nitride plate 100 can be improved.
　図８は、一実施形態に係る複合基板の斜視図である。複合基板２００は、互いに対向するように配置された一対の金属板１１０と、一対の金属板１１０の間に窒化ケイ素板１００を備える。一対の金属板１１０は、窒化ケイ素板１００の表面１００Ａ及び表面１００Ｂを覆うように窒化ケイ素板１００に接合されている。金属板１１０としては、銅板が挙げられる。窒化ケイ素板１００と、金属板１１０の形状及びサイズは同じであってもよいし、異なっていてもよい。複合基板２００は、上述の製造方法によって製造することができる。窒化ケイ素板１００の穴２０に形成される酸素リッチ層２２が低減されていることから、良好な外観を維持することができる。このような複合基板２００は、酸素リッチ層２２が低減されていることから信頼性に優れる。また、複合基板２００及びこれを用いる各製造設備の汚染を低減することができる。 FIG. 8 is a perspective view of the composite substrate according to the embodiment. The composite substrate 200 includes a pair of metal plates 110 arranged so as to face each other, and a silicon nitride plate 100 between the pair of metal plates 110. The pair of metal plates 110 are joined to the silicon nitride plate 100 so as to cover the surface 100A and the surface 100B of the silicon nitride plate 100. Examples of the metal plate 110 include a copper plate. The shape and size of the silicon nitride plate 100 and the metal plate 110 may be the same or different. The composite substrate 200 can be manufactured by the above-mentioned manufacturing method. Since the oxygen-rich layer 22 formed in the hole 20 of the silicon nitride plate 100 is reduced, a good appearance can be maintained. Such a composite substrate 200 is excellent in reliability because the oxygen-rich layer 22 is reduced. Further, it is possible to reduce the contamination of the composite substrate 200 and each manufacturing facility using the composite substrate 200.
　一実施形態に係る回路基板の製造方法は、上述の複合基板の製造方法に引き続いて、複合基板における金属板の一部を除去して区画部毎に独立した導体部を形成する工程を行う。この工程は、例えば、フォトリソグラフィによって行ってよい。具体的には、まず、複合基板の表面に感光性を有するレジストを印刷する。そして、露光装置を用いて、所定形状を有するレジストパターンを形成する。レジストはネガ型であってもよいしポジ型であってもよい。未硬化のレジストは、例えば洗浄によって除去する。 The circuit board manufacturing method according to one embodiment is a step of removing a part of the metal plate in the composite substrate to form an independent conductor portion for each section, following the above-mentioned composite substrate manufacturing method. This step may be performed, for example, by photolithography. Specifically, first, a photosensitive resist is printed on the surface of the composite substrate. Then, a resist pattern having a predetermined shape is formed by using an exposure apparatus. The resist may be a negative type or a positive type. The uncured resist is removed, for example, by washing.
　図９は、表面２００Ａにレジストパターン３０が形成された複合基板２００の一例を示す斜視図である。図９は、表面２００Ａ側のみを示しているが、表面２００Ｂ側にも同様のレジストパターンが形成されてよい。レジストパターン３０は、表面２００Ａ及び表面２００Ｂにおいて、窒化ケイ素板１００の各区画部１０に対応する領域に形成される。 FIG. 9 is a perspective view showing an example of the composite substrate 200 in which the resist pattern 30 is formed on the surface 200A. Although FIG. 9 shows only the surface 200A side, a similar resist pattern may be formed on the surface 200B side as well. The resist pattern 30 is formed on the surface 200A and the surface 200B in a region corresponding to each section 10 of the silicon nitride plate 100.
　レジストパターン３０を形成した後、エッチングによって、金属板１１０のうちレジストパターン３０に覆われていない部分を除去する。これによって、当該部分には窒化ケイ素板１００の表面１００Ａ及び表面１００Ｂが露出する。その後、レジストパターン３０を除去して、区画部１０毎に独立した導体部を形成する。以上の工程によって、回路基板が得られる。 After forming the resist pattern 30, the portion of the metal plate 110 that is not covered by the resist pattern 30 is removed by etching. As a result, the surface 100A and the surface 100B of the silicon nitride plate 100 are exposed in the portion. After that, the resist pattern 30 is removed to form an independent conductor portion for each compartment 10. A circuit board is obtained by the above steps.
　窒化ケイ素板１００は、スクライブラインＬ１，Ｌ２を構成する穴２０の内面における酸素リッチ層２２が低減されているため、良好な外観を有する回路基板を得ることができる。また、剥離する酸素リッチ層２２を低減できるため、露光装置等の内部の汚染を抑制することができる。また、導体部と窒化ケイ素板１００との接合性を向上することができる。 Since the oxygen-rich layer 22 on the inner surface of the holes 20 constituting the scribe lines L1 and L2 is reduced in the silicon nitride plate 100, a circuit board having a good appearance can be obtained. Further, since the oxygen-rich layer 22 to be peeled off can be reduced, contamination inside the exposure apparatus and the like can be suppressed. Further, the bondability between the conductor portion and the silicon nitride plate 100 can be improved.
　図１０は、一実施形態に係る回路基板の平面図である。回路基板３００は、窒化ケイ素板１００と、窒化ケイ素板１００を挟んで対向配置された導体部５０と、を備える。導体部５０は、区画部１０毎に独立して、表面１００Ａ及び表面１００Ｂ上に設けられている。すなわち、区画部１０毎に、互いに対向するように配置された一対の導体部５０が設けられている。 FIG. 10 is a plan view of the circuit board according to the embodiment. The circuit board 300 includes a silicon nitride plate 100 and conductor portions 50 arranged so as to face each other with the silicon nitride plate 100 interposed therebetween. The conductor portion 50 is independently provided on the surface 100A and the surface 100B for each compartment 10. That is, each section 10 is provided with a pair of conductors 50 arranged so as to face each other.
　回路基板３００は、スクライブラインＬ１，Ｌ２に沿って切断され、複数の分割基板に分割される。分割基板は例えばパワーモジュール等の部品として用いられる。分割基板における導体部５０には、例えば電子部品が実装される。回路基板３００は、上述の製造方法によって製造することができる。上述の製造方法では、穴２０の内面における酸素リッチ層２２が低減された窒化ケイ素板１００を用いていることから、回路基板３００及びその分割基板は良好な外観を維持することができる。分割基板を作製すると、スクライブラインＬ１，Ｌ２を構成していた穴２０の内面が外縁部に露出することとなる。このため、穴２０の内面における酸素リッチ層２２が低減された窒化ケイ素板１００を用いることによって、分割基板のみならず分割基板が搭載されるパワーモジュール等の良好な外観を維持することができる。また、パワーモジュールの信頼性も向上することができる。 The circuit board 300 is cut along the scribe lines L1 and L2 and divided into a plurality of divided boards. The divided substrate is used as a component of, for example, a power module. For example, electronic components are mounted on the conductor portion 50 of the divided substrate. The circuit board 300 can be manufactured by the above-mentioned manufacturing method. In the above-mentioned manufacturing method, since the silicon nitride plate 100 in which the oxygen-rich layer 22 on the inner surface of the hole 20 is reduced is used, the circuit board 300 and its divided substrate can maintain a good appearance. When the divided substrate is produced, the inner surface of the holes 20 forming the scribe lines L1 and L2 is exposed to the outer edge portion. Therefore, by using the silicon nitride plate 100 in which the oxygen-rich layer 22 on the inner surface of the hole 20 is reduced, not only the divided substrate but also the power module on which the divided substrate is mounted can maintain a good appearance. In addition, the reliability of the power module can be improved.
　以上、本開示の幾つかの実施形態について説明したが、本開示は上記実施形態に何ら限定されるものではない。例えば、各区画部１０に設けられる導体部５０の形状は同一である必要はなく、区画部１０毎に異なる形状を有していてもよい。また、窒化ケイ素板及び複合基板は、四角柱形状以外の形状を有していてもよい。 Although some embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments. For example, the shape of the conductor portion 50 provided in each compartment 10 does not have to be the same, and each compartment 10 may have a different shape. Further, the silicon nitride plate and the composite substrate may have a shape other than the quadrangular prism shape.
　回路基板３００における導体部５０には任意の表面処理を施してもよい。例えば、ソルダーレジスト等の保護層で導体部５０の表面の一部を被覆し、導体部５０の表面の他部にめっき処理を施してもよい。 Any surface treatment may be applied to the conductor portion 50 of the circuit board 300. For example, a part of the surface of the conductor portion 50 may be covered with a protective layer such as a solder resist, and the other portion of the surface of the conductor portion 50 may be plated.
［スクライブラインを有する窒化ケイ素板の作製］
（実施例１）
　平板形状の窒化ケイ素板（縦×横×厚さ＝１３９．７ｍｍ×１９０．５ｍｍ×０．３２ｍｍ）を準備した。この窒化ケイ素板の表面に、炭酸ガスレーザー加工機を用いて、一方向に沿って連なる複数の穴を形成し、スクライブラインを設けた。複数の穴の形成は、バーストパルスモードで、同一位置にレーザー光の照射を２回に分けて行った（ショット数：２）。１ショット当たりのレーザー光のエネルギー、及び、パルス幅は、表１に示すとおりであった。 [Manufacture of silicon nitride plate with scribe line]
(Example 1)
A flat plate-shaped silicon nitride plate (length x width x thickness = 139.7 mm x 190.5 mm x 0.32 mm) was prepared. A carbon dioxide laser processing machine was used to form a plurality of holes connected in one direction on the surface of the silicon nitride plate, and a scribe line was provided. The formation of the plurality of holes was performed by irradiating the same position with the laser beam in two times in the burst pulse mode (number of shots: 2). The energy of the laser beam and the pulse width per shot are as shown in Table 1.
（比較例１）
　実施例１と同じ形状及び材質の窒化ケイ素板を準備した。この窒化ケイ素板の表面に、炭酸ガスレーザー加工機を用いて、一方向に沿って連なる複数の穴を形成し、スクライブラインを設けた。それぞれの穴は、レーザー光の照射を１回のみ照射して形成した（ショット数：１）。１ショット当たりのレーザー光のエネルギー、及び、パルス幅は、表１に示すとおりであった。 (Comparative Example 1)
A silicon nitride plate having the same shape and material as that of Example 1 was prepared. A carbon dioxide laser processing machine was used to form a plurality of holes connected in one direction on the surface of the silicon nitride plate, and a scribe line was provided. Each hole was formed by irradiating the laser beam only once (number of shots: 1). The energy of the laser beam and the pulse width per shot are as shown in Table 1.
［スクライブラインを構成する穴の評価１］
　図１１は、スクライブラインを構成する複数の穴が形成された実施例１の窒化ケイ素板の表面及び断面のＳＥＭ写真を示している。図１１のＳＥＭ写真Ａは、複数の穴２０が形成された実施例１の窒化ケイ素板の表面を示している。図１１のＳＥＭ写真Ｂは、複数の穴２０が形成された実施例１の窒化ケイ素板の断面を示している。すなわち、ＳＥＭ写真Ｂは、窒化ケイ素板のスクライブラインが設けられた表面に垂直で且つスクライブラインを通る面で切断したときの断面を示している。 [Evaluation of holes that make up the scribe line 1]
FIG. 11 shows an SEM photograph of the surface and cross section of the silicon nitride plate of Example 1 in which a plurality of holes constituting the scribe line are formed. The SEM photograph A of FIG. 11 shows the surface of the silicon nitride plate of Example 1 in which a plurality of holes 20 are formed. The SEM photograph B of FIG. 11 shows a cross section of the silicon nitride plate of Example 1 in which a plurality of holes 20 are formed. That is, the SEM photograph B shows a cross section of the silicon nitride plate when cut along a surface perpendicular to the surface provided with the scribe line and passing through the scribe line.
　図１２は、スクライブラインを構成する複数の穴が形成された比較例１の窒化ケイ素板の表面及び断面のＳＥＭ写真を示している。図１２のＳＥＭ写真Ａは、複数の穴２０が形成された比較例１の窒化ケイ素板の表面を示している。図１２のＳＥＭ写真Ｂは、複数の穴２０が形成された比較例１の窒化ケイ素板の断面を示している。すなわち、ＳＥＭ写真Ｂは、窒化ケイ素板のスクライブラインが設けられた表面に垂直で且つスクライブラインを通る面で切断したときの断面を示している。 FIG. 12 shows an SEM photograph of the surface and cross section of the silicon nitride plate of Comparative Example 1 in which a plurality of holes constituting the scribe line are formed. The SEM photograph A of FIG. 12 shows the surface of the silicon nitride plate of Comparative Example 1 in which a plurality of holes 20 are formed. The SEM photograph B of FIG. 12 shows a cross section of the silicon nitride plate of Comparative Example 1 in which a plurality of holes 20 are formed. That is, the SEM photograph B shows a cross section of the silicon nitride plate when cut along a surface perpendicular to the surface provided with the scribe line and passing through the scribe line.
　図１３は、実施例１及び比較例１の、穴が形成された窒化ケイ素板の断面を、２５０倍及び５００倍に拡大して撮影したＳＥＭ写真である。図１４は、実施例１及び比較例１の、穴が形成された窒化ケイ素板の断面を、１０００倍及び２５００倍に拡大して撮影したＳＥＭ写真である。図１３及び図１４は、窒化ケイ素板のスクライブラインが形成された表面に垂直で且つスクライブラインの長手方向に垂直な面で切断したときの断面を示している。 FIG. 13 is an SEM photograph taken by magnifying the cross section of the silicon nitride plate having holes formed in Example 1 and Comparative Example 1 at 250 times and 500 times. FIG. 14 is an SEM photograph taken by magnifying the cross section of the silicon nitride plate having holes formed in Example 1 and Comparative Example 1 at 1000 times and 2500 times. 13 and 14 show a cross section of the silicon nitride plate when cut in a plane perpendicular to the surface on which the scribe line is formed and perpendicular to the longitudinal direction of the scribe line.
　図１３及び図１４に示されるように、比較例１では、穴の内面が窒化ケイ素の色よりも白い色の層で覆われていることが確認された。この白色の層のＥＰＭＡ分析を行ったところ、酸素を含有することが確認された。すなわち、白色の層は、窒化ケイ素板の内部よりも酸素を多く含有する酸素リッチ層であることが確認された。穴の底部における酸素リッチ層の最大厚みｔを測定したところ、１０μｍであった。 As shown in FIGS. 13 and 14, in Comparative Example 1, it was confirmed that the inner surface of the hole was covered with a layer having a color whiter than that of silicon nitride. When the EPMA analysis of this white layer was performed, it was confirmed that it contained oxygen. That is, it was confirmed that the white layer was an oxygen-rich layer containing more oxygen than the inside of the silicon nitride plate. The maximum thickness t of the oxygen-rich layer at the bottom of the hole was measured and found to be 10 μm.
　一方、実施例１では、比較例１よりも穴の内面及び底部における酸素リッチ層（酸素濃度は比較例１と同様）の厚みが薄かった。穴の底部における酸素リッチ層の最大厚みｔは、３μｍであった。このことから、穴を形成する際のレーザー光の照射を複数回に分けて行うことによって、穴の内面に形成される酸素リッチ層を低減できることが確認された。 On the other hand, in Example 1, the thickness of the oxygen-rich layer (oxygen concentration was the same as in Comparative Example 1) on the inner surface and bottom of the hole was thinner than that in Comparative Example 1. The maximum thickness t of the oxygen-rich layer at the bottom of the hole was 3 μm. From this, it was confirmed that the oxygen-rich layer formed on the inner surface of the hole can be reduced by irradiating the laser beam in a plurality of times when forming the hole.
［スクライブラインを構成する穴の評価２］
　実施例１と比較例１の窒化ケイ素板の表面のうち、スクライブラインが形成された部分を、光学顕微鏡（倍率：２５０倍）で観察し、穴２０の開口径ｒを測定した。その結果は、表１に示すとおりであった。また、実施例１と比較例１の窒化ケイ素板を、スクライブラインに沿って折って、図１１及び図１２のＳＥＭ写真Ｂに示すような断面を得た。この断面を光学顕微鏡（倍率：２５０倍）で観察し、穴２０の深さｄを測定した。その結果は、表１に示すとおりであった。 [Evaluation of holes that make up the scribe line 2]
On the surfaces of the silicon nitride plates of Example 1 and Comparative Example 1, the portion where the scrib line was formed was observed with an optical microscope (magnification: 250 times), and the opening diameter r of the hole 20 was measured. The results are shown in Table 1. Further, the silicon nitride plates of Example 1 and Comparative Example 1 were folded along the scribe line to obtain a cross section as shown in SEM photograph B of FIGS. 11 and 12. This cross section was observed with an optical microscope (magnification: 250 times), and the depth d of the hole 20 was measured. The results are shown in Table 1.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　実施例１の窒化ケイ素板では、スクライブラインを構成する穴の底部に生成する酸素リッチ層の厚みが、比較例１よりも大幅に小さかった。このような窒化ケイ素板は、酸素リッチ層の剥離による汚れが抑制され、良好な外観を維持することができる。また、酸素リッチ層の剥離に伴う信頼性の低下を抑制するとともに、各製造設備の汚染を低減することができる。 In the silicon nitride plate of Example 1, the thickness of the oxygen-rich layer formed at the bottom of the holes constituting the scribe line was significantly smaller than that of Comparative Example 1. Such a silicon nitride plate can suppress stains due to peeling of the oxygen-rich layer and can maintain a good appearance. In addition, it is possible to suppress a decrease in reliability due to peeling of the oxygen-rich layer and reduce contamination of each manufacturing facility.
　本開示によれば、良好な外観を維持しつつ、信頼性に優れる窒化ケイ素板及びその製造方法を提供することができる。また、良好な外観を維持しつつ、信頼性に優れる複合基板及びその製造方法を提供することができる。また、良好な外観を維持しつつ、信頼性に優れる回路基板及びその製造方法を提供することができる。 According to the present disclosure, it is possible to provide a silicon nitride plate having excellent reliability and a method for manufacturing the same while maintaining a good appearance. Further, it is possible to provide a composite substrate having excellent reliability and a method for manufacturing the same while maintaining a good appearance. Further, it is possible to provide a circuit board having excellent reliability and a method for manufacturing the same while maintaining a good appearance.
　１０…区画部、２０…穴、２０Ｂ…底部、２０Ｅ…開口部、２２…酸素リッチ層、３０…レジストパターン、４０…ろう材、１００…窒化ケイ素板、１００Ａ，１００Ｂ…表面、１１０…金属板、２００…複合基板、２００Ａ，２００Ｂ…表面、３００…回路基板、Ｌ１，Ｌ２…スクライブライン、ＶＬ１，ＶＬ２…仮想線。 10 ... partition, 20 ... hole, 20B ... bottom, 20E ... opening, 22 ... oxygen rich layer, 30 ... resist pattern, 40 ... brazing material, 100 ... silicon nitride plate, 100A, 100B ... surface, 110 ... metal plate , 200 ... Composite substrate, 200A, 200B ... Surface, 300 ... Circuit board, L1, L2 ... Scrivener line, VL1, VL2 ... Virtual line.

Claims (12)

  1. 　表面にスクライブラインを有する窒化ケイ素板の製造方法であって、
    　窒化ケイ素を含む基材の表面にレーザー光で複数の穴を形成して前記スクライブラインを設ける工程を有し、
    　前記複数の穴のそれぞれは、前記レーザー光を複数回に分けて照射することによって形成される、窒化ケイ素板の製造方法。     A method for manufacturing a silicon nitride plate having a scribe line on its surface.
    It has a step of forming a plurality of holes with laser light on the surface of a base material containing silicon nitride and providing the scribe line.
    A method for manufacturing a silicon nitride plate, wherein each of the plurality of holes is formed by irradiating the laser beam in a plurality of times.
  2. 　前記レーザー光を複数回に分けて照射する際の１回当たりの前記レーザー光のエネルギーは１５ｍＪ未満である、請求項１に記載の窒化ケイ素板の製造方法。 The method for manufacturing a silicon nitride plate according to claim 1, wherein the energy of the laser light per irradiation when the laser light is irradiated in a plurality of times is less than 15 mJ.
  3. 　前記表面における前記穴の開口径は５０μｍ以上であり、前記穴の深さは５０μｍ以上である、請求項１又は２に記載の窒化ケイ素板の製造方法。 The method for manufacturing a silicon nitride plate according to claim 1 or 2, wherein the opening diameter of the hole on the surface is 50 μm or more, and the depth of the hole is 50 μm or more.
  4. 　前記穴の底部における酸素リッチ層の最大厚みが８μｍ未満である、請求項１～３のいずれか一項に記載の窒化ケイ素板の製造方法。 The method for producing a silicon nitride plate according to any one of claims 1 to 3, wherein the maximum thickness of the oxygen-rich layer at the bottom of the hole is less than 8 μm.
  5. 　前記表面の方が前記穴の内面よりも酸素リッチ層の厚みが小さい、請求項１～４のいずれか一項に記載の窒化ケイ素板の製造方法。 The method for producing a silicon nitride plate according to any one of claims 1 to 4, wherein the surface is smaller in thickness of the oxygen-rich layer than the inner surface of the hole.
  6. 　表面にスクライブラインを有する窒化ケイ素板であって、
    　前記スクライブラインを構成する複数の穴の底部における酸素リッチ層の厚みが８μｍ未満である、窒化ケイ素板。     A silicon nitride plate having a scribe line on its surface.
    A silicon nitride plate having an oxygen-rich layer having a thickness of less than 8 μm at the bottoms of a plurality of holes constituting the scribe line.
  7. 　表面にスクライブラインを有する窒化ケイ素板であって、
    　前記表面の方が前記スクライブラインを構成する複数の穴の内面よりも酸素リッチ層の厚みが小さい、窒化ケイ素板。     A silicon nitride plate having a scribe line on its surface.
    A silicon nitride plate in which the thickness of the oxygen-rich layer is smaller on the surface than on the inner surfaces of the plurality of holes constituting the scribe line.
  8. 　前記表面における前記穴の開口径は５０μｍ以上であり、前記穴の深さは５０μｍ以上である、請求項６又は７に記載の窒化ケイ素板。 The silicon nitride plate according to claim 6 or 7, wherein the opening diameter of the hole on the surface is 50 μm or more, and the depth of the hole is 50 μm or more.
  9. 　請求項１～５のいずれか一項に記載の製造方法で得られた窒化ケイ素板の前記表面を覆うようにして金属板を前記窒化ケイ素板に接合して複合基板を得る工程を有する、複合基板の製造方法。 A composite comprising a step of joining a metal plate to the silicon nitride plate so as to cover the surface of the silicon nitride plate obtained by the production method according to any one of claims 1 to 5 to obtain a composite substrate. Substrate manufacturing method.
  10. 　請求項９に記載の製造方法で得られた複合基板における前記金属板の一部を除去し、前記スクライブラインで画定される区画部毎に独立する導体部を形成して回路基板を得る工程を有する、回路基板の製造方法。 A step of removing a part of the metal plate in the composite substrate obtained by the manufacturing method according to claim 9 and forming an independent conductor portion for each section defined by the scribing line to obtain a circuit board. A method for manufacturing a circuit board.
  11. 　請求項６～８のいずれか一項に記載の窒化ケイ素板と、
    　前記表面を覆うように前記窒化ケイ素板に接合される金属板と、を備える複合基板。     The silicon nitride plate according to any one of claims 6 to 8.
    A composite substrate comprising a metal plate bonded to the silicon nitride plate so as to cover the surface.
  12. 　請求項６～８のいずれか一項に記載の窒化ケイ素板と、
    　前記スクライブラインで画定される区画部毎に独立するように前記表面上に設けられる導体部と、を備える回路基板。     The silicon nitride plate according to any one of claims 6 to 8.
    A circuit board including a conductor portion provided on the surface of each compartment defined by the scribe line so as to be independent of each other.
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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014042066A (en) * 2008-06-20 2014-03-06 Hitachi Metals Ltd Ceramic assembled board
WO2016170895A1 (en) * 2015-04-21 2016-10-27 トーカロ株式会社 Method for roughening substrate, method for surface-treating substrate, method for producing spray-coated member, and spray-coated member
JP2017028192A (en) * 2015-07-27 2017-02-02 日立金属株式会社 Silicon nitride ceramic aggregate substrate and manufacturing method therefor, and manufacturing method for silicon nitride sintered substrate

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014042066A (en) * 2008-06-20 2014-03-06 Hitachi Metals Ltd Ceramic assembled board
WO2016170895A1 (en) * 2015-04-21 2016-10-27 トーカロ株式会社 Method for roughening substrate, method for surface-treating substrate, method for producing spray-coated member, and spray-coated member
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