CN113366591A - Printed wiring board - Google Patents
Printed wiring board Download PDFInfo
- Publication number
- CN113366591A CN113366591A CN202080011558.3A CN202080011558A CN113366591A CN 113366591 A CN113366591 A CN 113366591A CN 202080011558 A CN202080011558 A CN 202080011558A CN 113366591 A CN113366591 A CN 113366591A
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- Prior art keywords
- coil pattern
- wiring board
- printed wiring
- base film
- pattern
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- 230000000149 penetrating effect Effects 0.000 claims abstract description 8
- 239000004020 conductor Substances 0.000 description 29
- 238000007747 plating Methods 0.000 description 15
- 230000017525 heat dissipation Effects 0.000 description 11
- 230000005855 radiation Effects 0.000 description 7
- 230000000694 effects Effects 0.000 description 5
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 4
- 238000007772 electroless plating Methods 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002923 metal particle Substances 0.000 description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 3
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 3
- 239000010949 copper Substances 0.000 description 3
- 229910052802 copper Inorganic materials 0.000 description 3
- 238000009792 diffusion process Methods 0.000 description 3
- 238000009713 electroplating Methods 0.000 description 3
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 230000020169 heat generation Effects 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 229910052709 silver Inorganic materials 0.000 description 2
- 239000004332 silver Substances 0.000 description 2
- 229910000679 solder Inorganic materials 0.000 description 2
- 229920003002 synthetic resin Polymers 0.000 description 2
- 239000000057 synthetic resin Substances 0.000 description 2
- 229920000106 Liquid crystal polymer Polymers 0.000 description 1
- 239000004977 Liquid-crystal polymers (LCPs) Substances 0.000 description 1
- 239000004642 Polyimide Substances 0.000 description 1
- 210000000721 basilar membrane Anatomy 0.000 description 1
- 229910000365 copper sulfate Inorganic materials 0.000 description 1
- ARUVKPQLZAKDPS-UHFFFAOYSA-L copper(II) sulfate Chemical compound [Cu+2].[O-][S+2]([O-])([O-])[O-] ARUVKPQLZAKDPS-UHFFFAOYSA-L 0.000 description 1
- 238000010292 electrical insulation Methods 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- -1 polyethylene terephthalate Polymers 0.000 description 1
- 229920000139 polyethylene terephthalate Polymers 0.000 description 1
- 239000005020 polyethylene terephthalate Substances 0.000 description 1
- 229920001721 polyimide Polymers 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F17/00—Fixed inductances of the signal type
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K1/00—Printed circuits
- H05K1/02—Details
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K1/00—Printed circuits
- H05K1/16—Printed circuits incorporating printed electric components, e.g. printed resistor, capacitor, inductor
Landscapes
- Engineering & Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Structure Of Printed Boards (AREA)
- Parts Printed On Printed Circuit Boards (AREA)
- Coils Or Transformers For Communication (AREA)
Abstract
The printed wiring board according to the present invention comprises: a base film having an insulating property; a conductive pattern laminated on at least one surface side of the base film and including a spiral coil pattern; and 1 or more thermal via holes thermally connected to the coil pattern and penetrating a region of the base film where the conductive pattern is not laminated.
Description
Technical Field
The present invention relates to a printed wiring board.
Background
In recent years, there has been an increasing demand for downsizing electronic devices. In such electronic devices, printed wiring boards having a spiral coil pattern are widely used.
As this printed wiring board, for example, a planar coil described in japanese patent application laid-open No. 2004-342645 is proposed.
Patent document 1: japanese patent laid-open publication No. 2004-342645
Disclosure of Invention
In the above publication, it is described that a space factor of a planar coil can be increased by plating a coil-shaped base conductor layer with a plating solution containing copper sulfate, sulfuric acid, or ethylene glycol as a main component, thereby forming a planar coil element with narrow lines.
However, if the wiring density of the planar coil is increased as described above, the conductor resistance of the coil is likely to change due to heat generation of the planar coil when a current is applied. Further, a change in the conductor resistance of the wiring may affect the coil characteristics.
The present invention has been made in view of the above circumstances, and an object thereof is to provide a printed wiring board capable of suppressing a change in the conductor resistance of a coil pattern.
A printed wiring board according to the present invention proposed to solve the above problems includes: a base film having an insulating property; a conductive pattern laminated on at least one surface side of the base film and including a spiral coil pattern; and 1 or more thermal via holes thermally connected to the coil pattern and penetrating a region of the base film where the conductive pattern is not laminated.
ADVANTAGEOUS EFFECTS OF INVENTION
The printed wiring board according to the present invention can suppress a change in the conductor resistance of the coil pattern.
Drawings
Fig. 1 is a schematic plan view showing a printed wiring board according to an embodiment of the present invention.
Fig. 2 is an end view of a-a line portion of the printed wiring board of fig. 1.
Fig. 3 is a schematic plan view showing a printed wiring board according to an embodiment different from the printed wiring board of fig. 1.
Detailed Description
[ description of embodiments of the invention ]
First, embodiments of the present invention will be described.
The printed wiring board according to the present invention comprises: a base film having an insulating property; a conductive pattern laminated on at least one surface side of the base film and including a spiral coil pattern; and 1 or more thermal via holes thermally connected to the coil pattern and penetrating a region of the base film where the conductive pattern is not laminated.
The printed wiring board has 1 or more thermal via holes, and the 1 or more thermal via holes are thermally connected to the coil pattern and penetrate through a region of the base film where the conductive pattern is not laminated, so that even when the coil pattern generates heat, heat can be dissipated to the opposite surface side of the base film through the 1 or more thermal via holes. Thus, the printed wiring board can suppress the variation in the conductor resistance of the coil pattern.
Preferably, the 1 or more thermal via holes are formed more inward than the innermost circumference of the coil pattern. By forming the 1 or more thermal vias more inward than the innermost circumference of the coil pattern in this way, it is possible to increase the wiring density of the coil pattern and suppress a change in the conductor resistance of the coil pattern.
Preferably, the coil pattern has a pair of linear portions facing each other, and the plurality of heat passage holes are arranged along the pair of linear portions. As described above, the coil pattern has a pair of straight portions facing each other, and the plurality of heat via holes are arranged along the pair of straight portions, whereby the wiring density of the coil pattern can be increased, and the change in the conductor resistance of the coil pattern can be easily and reliably suppressed.
Preferably, the coil device has a plurality of dummy wirings adjacent to the outside of the coil pattern, and at least 1 of the dummy wirings is cut. As described above, by providing a plurality of dummy wirings adjacent to the outside of the coil pattern, the strength of the printed wiring board can be improved. In addition, by cutting at least 1 dummy wiring, it is possible to suppress heat diffusion in the planar direction, and it is possible to more reliably dissipate heat from the 1 or more thermal via holes.
In the present invention, "thermally connected" means a state in which heat can be transferred between the two at a temperature loss of 10% or less (in terms of celsius degrees), and may be a state in which the two are not in physical contact with each other. That is, the thermal via is thermally connected to the coil pattern means that, when a current is applied to the coil pattern, heat is transferred from the coil pattern to the thermal via with a temperature loss of 10% or less.
[ details of embodiments of the present invention ]
Hereinafter, a printed wiring board according to each embodiment of the present invention will be described in detail with reference to the drawings.
[ first embodiment ]
< printed wiring board >
The printed wiring board 1 of fig. 1 and 2 includes: a base film 2 having insulating properties; a conductive pattern 3 laminated on at least one surface side of the base film 2 and including a spiral coil pattern 3 a; and a plurality of thermal vias 4 thermally connected to the coil patterns 3a and penetrating through a region of the base film 2 where the conductive patterns 3 are not laminated. Although not shown, the printed wiring board 1 may have an insulating layer laminated on the base film 2 and the conductive pattern 3. The insulating layer may be formed using, for example, a solder resist, a cover coat, or the like.
Since the printed wiring board 1 has the plurality of heat via holes 4 thermally connected to the coil patterns 3a and penetrating the areas of the base film 2 where the conductive patterns 3 are not laminated, even when the coil patterns 3a generate heat, the heat can be dissipated to the opposite surface side of the base film 2 through the plurality of heat via holes 4. That is, the printed wiring board 1 can dissipate heat generated in the coil patterns 3a from the side of the base film 2 opposite to the side where the coil patterns 3a are arranged, through the plurality of heat passage holes 4. This allows the printed wiring board 1 to suppress heat retention in the area where the coil pattern 3a is formed, and to suppress a change in the conductor resistance of the coil pattern 3 a.
(basilar membrane)
The base film 2 is mainly composed of a synthetic resin and has electrical insulation properties. The base film 2 is a base material layer for forming the conductive pattern 3. The base film 2 may also have flexibility. When the base film 2 has flexibility, the printed wiring board 1 is configured as a flexible printed wiring board. The term "main component" refers to a component having the largest content in terms of mass, and refers to a component having a content of 50 mass% or more, for example.
Examples of the synthetic resin include polyimide, polyethylene terephthalate, liquid crystal polymer, and fluororesin.
In the case where the printed wiring board 1 is a flexible printed wiring board, the lower limit of the average thickness of the base film 2 is preferably 5 μm, and more preferably 10 μm. On the other hand, the upper limit of the average thickness of the base film 2 is preferably 50 μm, and more preferably 40 μm. If the average thickness of base film 2 is less than the above lower limit, the insulation strength of base film 2 may be insufficient. On the contrary, if the average thickness of the base film 2 exceeds the above upper limit, the printed wiring board 1 may become unnecessarily thick or the flexibility may be insufficient. In addition, in the present specification, "average thickness" represents an average value of thicknesses at arbitrary 10 points.
(conductive pattern)
The conductive pattern 3 is a layer made of a conductive conductor and includes a spiral coil pattern 3 a. In addition, the conductive pattern 3 includes a through hole 3b connected to an end of the coil pattern 3 a.
Coil pattern
The coil pattern 3a is, for example, a laminated body of a seed layer laminated on the base film 2 and an electroplating layer laminated on the seed layer. The coil pattern 3a may have a structure including a core composed of the seed layer and the plating layer, and a cover layer laminated on an outer surface of the core by plating. Examples of the main component of the seed layer include copper, nickel, and silver. The seed layer is formed by electroless plating, for example. The seed layer may be a sintered metal particle layer obtained by applying ink containing metal particles to the surface of the base film 2 and sintering the metal particles, or may be a laminate of the sintered metal particle layer and an electroless plating layer. The plating layer is formed by electroplating. Examples of the main component of the plating layer include copper, nickel, and silver.
The coil pattern 3a has a pair of opposing linear portions 3 c. The interval between the pair of linear portions 3c, that is, the interval between the inner peripheral edges of the pair of conductors disposed at the innermost peripheries of the pair of linear portions 3c, may be, for example, 200 μm to 3000 μm.
A region between the pair of linear portions 3c is configured as a heat radiation region R for radiating heat generated in the coil pattern 3a to a surface side of the base film 2 opposite to the surface on the laminated coil pattern 3a side. The heat dissipation region R is elongated in a longitudinal direction which is an extending direction of the pair of linear portions 3 c. As will be described later, a plurality of heat passage holes 4 are arranged in the heat radiation region R.
The interval between adjacent conductors of the coil pattern 3a is preferably uniform except for the heat dissipation region R described above. The lower limit of the average interval between the adjacent conductors is preferably 5 μm, and more preferably 10 μm. On the other hand, the upper limit of the average interval is preferably 50 μm, and more preferably 30 μm. If the average interval is smaller than the lower limit, the coil pattern 3a may not be easily formed. On the other hand, if the average interval exceeds the upper limit, a desired wiring density may not be obtained. In addition, when the average interval is small, the conductor resistance of the coil pattern 3a is likely to change due to heat generation. However, since the printed wiring board 1 can intensively dissipate heat through the plurality of thermal vias 4, even when the average interval is equal to or less than the upper limit, the variation in the conductor resistance can be sufficiently suppressed. Further, "average interval" means an average value of intervals of arbitrary 10 points.
The width of the conductor constituting the coil pattern 3a is preferably uniform. The lower limit of the average width of the conductor is preferably 5 μm, and more preferably 10 μm. On the other hand, the upper limit of the average width of the conductor is preferably 50 μm, and more preferably 30 μm. If the average width is smaller than the lower limit, the coil pattern 3a may not be easily formed. On the other hand, if the average width exceeds the upper limit, the planar area of the coil pattern 3a becomes large, which may be contrary to the demand for downsizing the printed wiring board 1. Further, "average width" means an average value of the widths of arbitrary 10 points.
The lower limit of the average thickness of the conductor constituting the coil pattern 3a is preferably 5 μm, and more preferably 10 μm. On the other hand, the upper limit of the average thickness is preferably 90 μm, and more preferably 70 μm. If the average thickness is less than the lower limit, the conductor resistance may be increased. On the other hand, if the average thickness exceeds the upper limit, there is a possibility that the requirement for thinning the printed wiring board 1 may be contradicted.
(thermal via hole)
As shown in fig. 2, the plurality of thermal via holes 4 penetrate in the thickness direction of the base film 2. The plurality of thermal vias 4 are formed further inward than the innermost circumference of the coil pattern 3 a. Specifically, the plurality of thermal vias 4 are formed in the heat dissipation region R. In the heat dissipation region R, the surfaces, preferably both surfaces, of the plurality of thermal vias 4 are exposed to the outside (that is, the surfaces of the plurality of thermal vias 4 are not covered with another member such as an insulating layer). In this printed wiring board 1, the plurality of thermal via holes 4 are formed inside the innermost circumference of the coil pattern 3a, so that the wiring density of the coil pattern 3a can be increased and the change in the conductor resistance of the coil pattern 3a can be suppressed.
The plurality of thermal via holes 4 are arranged along the pair of linear portions 3 c. By arranging the plurality of heat via holes 4 along the pair of straight portions 3c, thermal connection between the coil pattern 3a and the plurality of heat via holes 4 is facilitated and secured. In addition, according to this structure, heat is easily transferred uniformly to the plurality of thermal vias 4 from the entire region of the coil pattern 3 a. Therefore, the wiring density of the coil pattern 3a can be increased, and the change in the conductor resistance of the coil pattern 3a can be easily and reliably suppressed.
The plurality of thermal vias 4 are formed, for example, by forming a through hole penetrating the base film 2 in the thickness direction thereof and performing metal plating on the inner circumferential surface of the through hole and both surfaces of the base film 2 continuing from the inner circumferential surface. As the metal, copper is preferable. The metal plating is, for example, electroless plating. After the electroless plating, electroplating may be performed.
In the present embodiment, each heat passage hole 4 is cylindrical. Each thermal via hole 4 has a land portion on both sides in the axial direction. In the printed wiring board 1, it is preferable that the average diameter of the plurality of thermal vias 4 is small and the number of the thermal vias 4 is large. This makes it possible to arrange the heat passage holes 4 having a constant thermal conductivity densely in the planar direction, and to easily radiate heat uniformly from the entire region of the coil pattern 3 a.
The lower limit of the average diameter W of the plurality of thermal via holes 4 (the average inner diameter of the through-holes) is preferably 10 μm, and more preferably 25 μm. On the other hand, the upper limit of the average diameter W is preferably 300 μm, and more preferably 100 μm. If the above average diameter W is less than the above lower limit, the attachment of the metal plating may become unreliable. On the other hand, if the average diameter W exceeds the upper limit, it is difficult to densely arrange the plurality of heat passage holes 4, and the heat radiation performance with respect to the entire coil pattern 3a may become insufficient. The "diameter" refers to a diameter converted into a perfect circle having an equal area. In addition, "average diameter of the thermal via hole" means an average value of diameters at end openings formed at both sides of the through hole of the base film.
The plurality of heat passage holes 4 are linearly arranged along the longitudinal direction of the heat radiation region R. The lower limit of the number of the plurality of heat passage holes 4 arranged in the heat radiation region R is preferably 3, and more preferably 4. On the other hand, the upper limit of the number is preferably 8, and more preferably 6. If the number is less than the lower limit, the heat radiation performance with respect to the entire coil pattern 3a may become insufficient. Conversely, if the number exceeds the upper limit, the heat dissipation area R becomes unnecessarily large, which may be contrary to the demand for miniaturization of the printed wiring board 1.
The lower limit of the average distance D1 between adjacent thermal vias 4 is preferably 10 μm, and more preferably 25 μm. On the other hand, the upper limit of the average distance D1 is preferably 300 μm, and more preferably 100 μm. If the average distance D1 is less than the lower limit, it may be difficult to form a plurality of heat passage holes 4 or the strength of the base film 2 may be reduced. On the other hand, if the average distance D1 exceeds the upper limit, the heat dissipation performance may become insufficient for the entire coil pattern 3a, or the heat dissipation area R may become unnecessarily large, which may be contrary to the demand for downsizing the printed wiring board 1. The interval between adjacent thermal vias is the minimum distance between adjacent thermal vias.
[ second embodiment ]
The printed wiring board 11 of fig. 3 has: a base film having an insulating property; a conductive pattern 13 laminated on at least one surface side of the base film, and including a spiral coil pattern 13 a; and a plurality of thermal vias 4 thermally connected to the coil patterns 13a and penetrating through a region of the base film where the conductive patterns 13 are not laminated. Although not shown, the printed wiring board 11 may have an insulating layer laminated on the base film and the conductive pattern 13. The insulating layer may be formed using, for example, a solder resist, a cover coat, or the like. The base film of the printed wiring board 11 may have the same structure as the base film 2 of the printed wiring board 1 of fig. 1. The thermal via holes 4 of the printed wiring board 11 are the same as the thermal via holes 4 of the printed wiring board 1 of fig. 1, and therefore, the same reference numerals are given thereto and the description thereof is omitted.
The printed wiring board 11 has a plurality of dummy wirings 15 adjacent to the outside of the coil pattern 13 a. Further, at least 1 dummy wiring 15 is cut. In the printed wiring board 11, the plurality of dummy wires 15 are provided adjacent to the coil pattern 13a, so that the strength of the printed wiring board can be improved. In addition, in the printed wiring board 11, by dividing at least 1 dummy wiring 15, it is possible to suppress heat diffusion from the area where the coil pattern 13a is formed to the outside in the planar direction, and it is possible to more reliably dissipate heat from the plurality of heat passage holes 4.
(conductive pattern)
The conductive pattern 13 is a layer made of a conductive conductor, and includes a spiral coil pattern 13 a. In addition, the conductive pattern 13 includes a through hole 13b connected to an end of the coil pattern 13 a.
Coil pattern
The coil pattern 13a may be a laminate of a seed layer laminated on the base film and a plating layer laminated on the seed layer, as in the coil pattern 3a of the printed wiring board 1 of fig. 1. The coil pattern 13a may have a core body composed of the seed layer and the plating layer, and a cover layer laminated on an outer surface of the core body by plating.
The coil pattern 13a has a pair of opposing linear portions (1 st linear portion 13 c). The interval between the pair of 1 st straight portions 13c facing each other in the coil pattern 13a may be the same as the interval between the pair of straight portions 3c in the printed wiring board 1 of fig. 1. In addition, the coil pattern 13a has 1 or more 2 nd straight portions 13d on one side or both sides in the extending direction of the pair of 1 st straight portions 13 c.
A region between the pair of 1 st linear portions 13c is configured as a heat radiation region R for radiating heat generated in the coil pattern 13a to a surface side of the base film opposite to the surface on the laminated coil pattern 13a side. The heat dissipation region R is elongated in the longitudinal direction, which is the extending direction of the pair of 1 st linear portions 13 c. In the heat dissipation region R, a plurality of thermal vias 4 are arranged in the same manner as in the printed wiring board 1 of fig. 1.
The interval between the adjacent conductors of the coil pattern 13a is preferably uniform except for the heat dissipation region R. The average distance between the adjacent conductors may be the same as that of the printed wiring board 1 of fig. 1. In addition, the width of the conductor constituting the coil pattern 13a is preferably uniform. The average width of the conductors may be the same as that of the printed wiring board 1 of fig. 1.
(pseudo wiring)
The dummy wirings 15 are arranged in a state of being electrically insulated from the conductive pattern 13. The plurality of dummy wires 15 may be, for example, a laminate of a seed layer laminated on a base film and a plating layer laminated on the seed layer, or may have a structure including a core body composed of the seed layer and the plating layer and a cover layer laminated on an outer surface of the core body by plating, as in the coil pattern 13 a.
The plurality of dummy wires 15 are disposed adjacent to the coil pattern 13a, that is, without interposing other wires or the like therebetween. In addition, the printed wiring board 11 may include 1 or more dummy wirings 15 that are not adjacent to the coil pattern 13a in a part of the dummy wirings 15. The dummy wiring 15 not adjacent to the coil pattern 13a is, for example, a dummy wiring 15 arranged in parallel with the coil pattern 13a with another dummy wiring 15 interposed therebetween.
At least some of the dummy wires 15 are arranged in a direction intersecting the extending direction of the adjacent coil patterns 13 a. In the present embodiment, the plurality of dummy wirings 15 includes a plurality of 1 st dummy wirings 15a intersecting with the 2 nd straight line portion 13 d. The 1 st dummy wirings 15a are arranged orthogonal to the 2 nd straight line portion 13 d.
The lower limit of the average distance D2 between the 1 st dummy wiring 15a and the coil pattern 13a is preferably 5 μm. On the other hand, the upper limit of the average distance D2 is preferably 50 μm, and more preferably 30 μm. If the above average interval D2 is smaller than the above lower limit, short circuits may occur between the plurality of 1 st dummy wirings 15a and the coil patterns 13 a. On the contrary, if the average interval D2 exceeds the upper limit, the effect of improving the strength by the plurality of 1 st dummy wirings 15a may become insufficient.
The 1 st dummy wirings 15a are arranged in parallel. Further, the 1 st dummy wirings 15a are partially cut in the longitudinal direction. In this way, by cutting off a part of the plurality of 1 st dummy wirings 15a in the longitudinal direction, it is possible to easily suppress heat generated in the coil pattern 13a from being diffused outside the formation region of the coil pattern 13 a.
The cutting positions of the plurality of 1 st dummy wirings 15a are preferably random. In other words, the cut positions of the 1 st dummy wirings 15a are preferably not arranged in a straight line. In this way, by making the cutting positions of the plurality of 1 st dummy wirings 15a random, it is possible to suppress a decrease in strength caused by cutting the plurality of 1 st dummy wirings 15 a.
The cutoff positions of the plurality of 1 st dummy wirings 15a are preferably close to the coil pattern 13 a. The plurality of 1 st dummy wires 15a are cut at positions close to the coil pattern 13a, and thus, the heat generated in the coil pattern 13a can be easily and reliably prevented from being diffused out of the formation region of the coil pattern 13 a. The average distance between the cut regions of the 1 st dummy wirings 15a and the coil pattern 13a may be, for example, 100 μm to 1500 μm.
The average length L of the cut regions of the plurality of 1 st dummy wirings 15a is preferably larger than the average interval D2 between the plurality of 1 st dummy wirings 15a and the coil pattern 13 a. In the printed wiring board 11, the 1 st dummy wiring 15a is disposed separately from the coil pattern 13 a. However, since the gaps of the plurality of 1 st dummy wirings 15a and the coil patterns 13a are arranged in a straight line, if the separation distance is increased, the effect of improving the strength of the printed wiring board 11 becomes insufficient. On the other hand, since the plurality of 1 st dummy wirings 15a can be formed at random, the strength improvement effect is not likely to be insufficient even if the length of the cut region is large. Further, by setting the length of the cutoff region to be large, thermal spread can be reliably suppressed.
The lower limit of the average length L of the cut regions of the 1 st dummy wirings 15a is preferably 10 μm, and more preferably 30 μm. On the other hand, the upper limit of the average length L is preferably 500 μm, and more preferably 100 μm. If the average length L is less than the lower limit, the cutoff region may not sufficiently suppress heat diffusion. On the other hand, if the average length L exceeds the upper limit, the cut area becomes unnecessarily large, and the effect of improving the strength of the printed wiring board 1 by the plurality of 1 st dummy wirings 15a may become insufficient.
[ other embodiments ]
The embodiments disclosed herein are illustrative in all respects and should not be construed as being restrictive. The scope of the present invention is not limited to the structure of the above-described embodiments, but is defined by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.
For example, although the above embodiment has been described with respect to the structure having a plurality of thermal vias, the printed wiring board may have only 1 thermal via. In addition, from the viewpoint of being able to increase the wiring density of the coil pattern, it is preferable that 1 or more thermal via holes be formed further inside than the innermost circumference of the coil pattern, but if there is no limitation on the wiring density, they may be formed, for example, between adjacent conductors of the coil pattern, or may be formed outside the coil pattern.
The printed wiring board may have a conductive pattern only on one surface side of the base film, or may have a conductive pattern on both surface sides of the base film. The shape of the coil pattern of the printed wiring board is not limited to the shape of the above-described embodiment, and for example, the printed wiring board may not have a pair of opposing linear portions.
When the printed wiring board has a plurality of dummy wirings, the specific arrangement of the dummy wirings is not limited to the arrangement described in the above embodiment. The printed wiring board may have 1 or more dummy wirings arranged parallel to the extending direction of the coil pattern, and the 1 or more dummy wirings may be cut.
Industrial applicability
As described above, the printed wiring board according to the embodiment of the present invention can suppress a change in the conductor resistance of the coil pattern, and therefore, the printed wiring board can be applied to various electronic apparatuses.
Description of the reference numerals
1. 11 printed wiring board
2 base film
3. 13 conductive pattern
3a, 13a coil pattern
3b, 13b through hole
3c straight line part
4 thermal via hole
15 dummy wiring
R heat dissipation area
Claims (4)
1. A printed wiring board having:
a base film having an insulating property;
a conductive pattern laminated on at least one surface side of the base film and including a spiral coil pattern; and
and 1 or more thermal via holes thermally connected to the coil pattern and penetrating a region of the base film where the conductive pattern is not laminated.
2. The printed wiring board of claim 1,
the 1 or more thermal via holes are formed further inward than the innermost circumference of the coil pattern.
3. The printed wiring board of claim 2,
the coil pattern has a pair of opposed linear portions,
the plurality of thermal via holes are arranged along the pair of linear portions.
4. The printed wiring board of claim 1, 2, or 3,
a plurality of dummy wirings adjacent to the outside of the coil pattern,
at least 1 of the dummy wirings is cut.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2019034037 | 2019-02-27 | ||
| JP2019-034037 | 2019-02-27 | ||
| PCT/JP2020/007491 WO2020175477A1 (en) | 2019-02-27 | 2020-02-25 | Printed wiring board |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113366591A true CN113366591A (en) | 2021-09-07 |
Family
ID=72239208
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202080011558.3A Pending CN113366591A (en) | 2019-02-27 | 2020-02-25 | Printed wiring board |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JP7409599B2 (en) |
| CN (1) | CN113366591A (en) |
| WO (1) | WO2020175477A1 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP7357582B2 (en) * | 2020-04-20 | 2023-10-06 | 住友電気工業株式会社 | flexible printed wiring board |
| JP7452507B2 (en) | 2021-09-25 | 2024-03-19 | 株式会社村田製作所 | inductor |
| JP7517293B2 (en) | 2021-09-25 | 2024-07-17 | 株式会社村田製作所 | Inductors |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08293417A (en) * | 1995-04-24 | 1996-11-05 | Sumitomo Special Metals Co Ltd | Printed coil component and printed coil board |
| US20020185919A1 (en) * | 2001-06-08 | 2002-12-12 | Aerotech, Inc. | Printed circuit linear motor |
| CN1819743A (en) * | 2004-12-16 | 2006-08-16 | 三井金属矿业株式会社 | Flexible printed wiring board |
| CN103582292A (en) * | 2012-08-08 | 2014-02-12 | 佳能株式会社 | Printed wiring board, printed circuit board, and printed circuit board manufacturing method |
| US20180317313A1 (en) * | 2015-11-13 | 2018-11-01 | Schaeffler Technologies AG & Co. KG | Multi-layer printed circuit board having a printed coil and method for the production thereof |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5794417B2 (en) * | 2011-06-28 | 2015-10-14 | 日立工機株式会社 | Disk motor and electric working machine equipped with the same |
| JP6084148B2 (en) * | 2013-03-15 | 2017-02-22 | オムロンオートモーティブエレクトロニクス株式会社 | Coil integrated printed circuit board, magnetic device |
-
2020
- 2020-02-25 WO PCT/JP2020/007491 patent/WO2020175477A1/en active Application Filing
- 2020-02-25 CN CN202080011558.3A patent/CN113366591A/en active Pending
- 2020-02-25 JP JP2021502274A patent/JP7409599B2/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08293417A (en) * | 1995-04-24 | 1996-11-05 | Sumitomo Special Metals Co Ltd | Printed coil component and printed coil board |
| US20020185919A1 (en) * | 2001-06-08 | 2002-12-12 | Aerotech, Inc. | Printed circuit linear motor |
| CN1819743A (en) * | 2004-12-16 | 2006-08-16 | 三井金属矿业株式会社 | Flexible printed wiring board |
| CN103582292A (en) * | 2012-08-08 | 2014-02-12 | 佳能株式会社 | Printed wiring board, printed circuit board, and printed circuit board manufacturing method |
| US20180317313A1 (en) * | 2015-11-13 | 2018-11-01 | Schaeffler Technologies AG & Co. KG | Multi-layer printed circuit board having a printed coil and method for the production thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2020175477A1 (en) | 2020-09-03 |
| JP7409599B2 (en) | 2024-01-09 |
| JPWO2020175477A1 (en) | 2021-12-23 |
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Application publication date: 20210907 |
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