JP2011049520A - Printed wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printed wiring board allowing a large current to be carried by connecting the front side to the back side of the printed wiring board by a simple structure. <P>SOLUTION: This printed wiring board 10 is composed by laminating a first surface-side circuit pattern board 20, a core resin layer 30 and a second surface-side circuit pattern board 40. A projecting part 22 and a tubular part 42 formed by pressing the first surface-side circuit pattern board 20 and the second surface-side circuit pattern 40 each being large in thickness, respectively, allow a large current to be carried. The projecting part 22 and the tubular part 42 can be inexpensively formed by pressing work. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a printed wiring board that is suitably used in electric vehicles, hybrid vehicles, and the like.

A printed wiring board for controlling a large current of a high-output motor such as an electric vehicle or a hybrid vehicle uses a combination of bus bars for flowing a large current as disclosed in Patent Document 1.

In general, a through-hole conductor in which plating is provided on the side wall of a through-hole penetrating the printed wiring board is used to connect the front and back surfaces of the printed wiring board. Patent Document 2 discloses a printed wiring board in which a through hole is filled with a conductive paste. Patent Document 3 discloses a printed wiring board in which a metal piece is inserted into a through hole. Patent Document 4 discloses a printed wiring board using a conductive paste and a copper ball for connection between layers.

JP 2003-249288 A Japanese Patent Laid-Open No. 11-74640 JP 2005-243911 A JP 2008-182163 A

However, in Patent Document 1, since a bus bar having a complicated shape is used, there is a problem that the component structure is complicated and the number of assembly steps is large. Patent Document 2 uses a conductive paste, Patent Document 3 uses a metal piece, and Patent Document 4 uses a conductive paste and a copper ball, which increases the number of manufacturing steps and increases the cost. In addition, when a high-resistance solder paste is used for interlayer connection, a problem of heat generation occurs when a large current is passed.

The present invention has been made to solve the above-described problems, and the object of the present invention is to flow a large current by connecting the front side and the back side of the printed wiring board with a simple configuration. It is in providing the printed wiring board which can be performed.

In order to achieve the above object, the invention of claim 1 is a printed wiring board comprising a resin layer and a first surface side plate-like circuit pattern and a second surface side plate-like circuit pattern facing each other through the resin layer,
The first surface side plate circuit pattern and the second surface side plate circuit pattern are provided on one side of the first surface side plate circuit pattern or the second surface side plate circuit pattern, and on the other side. It is technically characterized by being electrically connected by a facing portion facing the outer periphery of the convex portion.

In the printed wiring board according to claim 1, the first surface side plate-like circuit pattern and the second surface side plate-like circuit pattern have a sufficient conductor cross-sectional area secured by the convex portion and the opposing portion facing the outer periphery of the convex portion. Therefore, it is possible to flow a large current by connecting the front side and the back side of the printed wiring board with a simple configuration.

In the printed wiring board according to the second aspect, since the facing portion is formed in a cylindrical shape so as to be fitted into the outer periphery of the convex portion, the conductor cross-sectional area can be sufficiently secured.

In the printed wiring board according to claim 3, the convex part and the opposing part formed by pressing the thick first surface side plate-like circuit pattern and the second surface side plate-like circuit pattern, respectively, are thick and large. Current can flow. The convex portion and the facing portion can be formed at low cost by press working.

In the printed wiring board according to claim 4, since the first surface side plate-like circuit pattern and the second surface side plate-like circuit pattern are simultaneously formed by pressing together with the convex portion and the opposing portion, the convex portion and the opposing portion are formed. The first surface side plate-like circuit pattern and the second surface side plate-like circuit pattern that are provided can be manufactured at low cost.

In the printed wiring board according to the fifth aspect, the convex portion and the facing portion are electrically connected by a low melting point metal (or conductive resin). In the process of mounting the component by reflowing the low melting point metal on the first surface side plate circuit pattern and the second surface side plate circuit pattern, the low melting point metal can be poured between the convex portion and the facing portion. The convex portion and the facing portion can be electrically connected together in the component mounting process.

In the printed wiring board according to the sixth aspect, the convex portion and the facing portion are connected by joining (welding). The convex portion and the cylindrical portion can be electrically connected by welding such as a spot or ultrasonic bonding. Thereby, heat generation at the time of connection can be suppressed as compared with a case where a large current is passed using a high-resistance solder paste for interlayer connection.

In the printed wiring board according to claim 7, since the concave portion that engages with a part of the convex portion is formed on the joint surface of the facing portion, positioning of the convex portion and the facing portion at the time of joining is more reliably performed. Can do.

In the printed wiring board according to claim 8, since the first surface side plate-like circuit pattern and the second surface side plate-like circuit pattern are fixed to the resin layer by an adhesive, a circuit pattern is provided on the resin layer by film formation or the like. As compared with, the thickness of the circuit pattern can be easily increased, and the time for forming the printed wiring board can be shortened.

In the printed wiring board according to claim 9, since the adhesive is a silicone-based adhesive, it has high elasticity compared to other adhesives, so even when the circuit pattern is deformed due to residual stress at the time of forming the circuit pattern Further, it is possible to eliminate peeling of the adhesive and damage to the circuit pattern.

In the printed wiring board according to claim 10, since a core material having higher heat dissipation and an adhesive having higher insulating properties are usually employed as the resin layer and the adhesive, the resin layer is replaced with a resin layer. Since the core material to be employed does not require insulation, a member having higher heat dissipation can be employed as the core material.

In the printed wiring board according to claim 11, instead of the resin layer and the adhesive, an adhesive member having one or a plurality of heat dissipation properties (for example, a metal member such as copper) is included. Since the insulating layer is employed, it is not necessary to apply an adhesive or the like, and the heat dissipation property of the insulating layer can be enhanced by a member having an internal heat dissipation property.

It is sectional drawing of the printed wiring board which concerns on 1st Embodiment of this invention. It is a manufacturing-process figure of the printed wiring board of 1st Embodiment. It is a manufacturing-process figure of the printed wiring board of 1st Embodiment. It is a manufacturing process figure of the printed wiring board concerning a 2nd embodiment of the present invention. It is an expanded sectional view showing an important section of a printed wiring board concerning a modification of a 2nd embodiment. It is an expanded sectional view showing an important section of a printed wiring board concerning a 3rd embodiment of the present invention. It is an expanded sectional view showing an important section of a printed wiring board concerning a modification of a 3rd embodiment. It is an expanded sectional view showing an important section of a printed wiring board concerning a modification of a 3rd embodiment. It is sectional drawing of the printed wiring board which concerns on 4th Embodiment of this invention. It is an expanded sectional view showing an important section of a printed wiring board concerning a modification of a 4th embodiment. It is an expanded sectional view showing an important section of a printed wiring board concerning the 1st modification of a 1st embodiment. It is an expanded sectional view showing an important section of a printed wiring board concerning the 2nd modification of a 1st embodiment. It is an expanded sectional view showing an important section of a printed wiring board concerning the 3rd modification of a 1st embodiment.

[First embodiment]
A printed wiring board according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view of a printed wiring board 10 according to the first embodiment. The printed wiring board 10 is formed by laminating a first surface side circuit pattern board 20 on a lower surface and a second surface side circuit pattern board 40 on an upper surface on a core resin layer 30. That is, the first surface side circuit pattern board 20 and the second surface side circuit pattern board 40 are arranged to face each other with the core resin layer 30 interposed therebetween. The first surface side circuit pattern plate 20 and the second surface side circuit pattern plate 40 are arranged on the outer periphery of the cylindrical convex portion 22 formed on the first surface side circuit pattern plate 20. The cylinder-shaped cylindrical part 42 formed in is inserted and electrically connected. The cylindrical portion 42 is formed so as to face the outer surface (outer peripheral surface) of the convex portion 22 with a predetermined gap, and the convex portion 22 and the cylindrical portion 42 are formed by an intervening solder 60. Electrically connected. Predetermined portions of the first surface side circuit pattern board 20 and the second surface side circuit pattern board 40 are covered with solder 60, and an electronic component 62 is mounted via the solder 60. The first surface side circuit pattern plate 20 and the second surface side circuit pattern plate 40 are examples of the “first surface side plate circuit pattern” and the “second surface side plate circuit pattern” described in the claims. Correspondingly, the convex part 22 and the cylindrical part 42 can correspond to an example of “convex part” and “opposing part” described in the claims.

The first surface side circuit pattern plate 20 and the second surface side circuit pattern plate 40 are formed by punching a pattern on a copper plate having a thickness of 0.5 to 2.0 mm, and combining a plurality of pieces of circuit patterns. . For example, the second surface side circuit pattern board 40 is formed by combining two punched circuit patterns. At the time of this pressing, the convex part 22 of the 1st surface side circuit pattern board 20 and the cylindrical part 42 of the 2nd surface side circuit pattern board 40 are shape | molded simultaneously. In this embodiment, a metal plate is used instead of a metal foil. Here, the metal plate defined in this embodiment means a plate-like body that can be punched and can maintain its shape without applying external force such as tension, and maintains its own shape when performing etching. It is a concept that excludes metal foil that cannot be obtained. The core resin layer 30 is formed by curing a prepreg in which a core material such as glass cloth is impregnated with a resin such as epoxy, and is formed to have a thickness of 0.5 to 4.0 mm.

Subsequently, the manufacturing process of the printed wiring board according to the first embodiment will be described with reference to FIGS.
A copper plate 20α having a thickness of 0.5 to 2.0 mm shown in FIG. 2A is pressed between the upper die 50U and the lower die 50D shown in FIG. The convex portion 22 of the first surface side circuit pattern board 20 is formed by the convex portion 54 of the mold 50D, and the opening of the first surface side circuit pattern board 20 is formed by the upper convex portion 56 and the lower mold concave portion 58. 24 is drilled. FIG. 2C shows the first surface side circuit pattern board 20 after press working. The convex portion 22 has a height h1: 1.0 to 4.5 mm and an outer diameter D1: 3 to 5 mm. Similarly, the 2nd surface side circuit pattern board 40 forms the cylindrical part 42, the opening 44, and the opening 46 simultaneously by press work. The cylindrical portion 42 has a height h2 of 0.5 to 4.0 mm and an inner diameter D2 of D1 + 0.5 mm. The first surface side circuit pattern plate 20 and the second surface side circuit pattern plate 40 are positioned so that the convex portion 22 and the cylindrical portion 42 correspond to each other, and the inner diameter corresponding to the cylindrical portion 42 therebetween. D3: D2 + (thickness of tubular portion 42 × 2) +1 mm of prepreg 30α having an opening 32 formed therein is interposed.

The cylindrical portion 42 is fitted into the convex portion 22, the first surface side circuit pattern plate 20 and the second surface side circuit pattern plate 40 are pressed and heated with the prepreg interposed therebetween, and the prepreg is thermoset to cure the core resin layer. 30 is formed. The resin flows out from the prepreg during heating, but the cylindrical portion 42 serves as a barrier wall, and the resin does not enter between the cylindrical portion 42 and the convex portion 22. A through hole 34 for communicating the opening 24 of the first surface side circuit pattern board 20 and the opening 46 of the second surface side circuit pattern board 40 is formed in the core resin layer 30 (FIG. 3A). Next, a solder resist 64 is formed on the surfaces of the first surface side circuit pattern plate 20 and the second surface side circuit pattern plate 40 (FIG. 3B). Solder 60 is applied to the solder resist non-formation portions of the first side circuit pattern board 20 and the second side circuit pattern board 40 (FIG. 3C), and an electronic component 62 such as a capacitor is placed at a predetermined position. (FIG. 3D). Finally, reflow is performed to mount the electronic component 62 on the second surface side circuit pattern board 40 via the solder 60, and the solder 60 is poured between the convex portion 22 and the cylindrical portion 42. The connection with the cylindrical part 42 is taken (FIG. 1).

In the printed wiring board of the first embodiment, the first surface side circuit pattern board 20 and the second surface side circuit pattern board 40 are cylindrical projections 22 and cylindrical portions that are fitted on the outer periphery of the projections 22. Since the conductor is electrically connected after sufficiently securing the cross-sectional area of the conductor, the front surface side and the back surface side of the printed wiring board can be connected with a simple configuration to allow a large current to flow. In addition, the convex part 22 is not restricted to being formed in a cylindrical shape, but may be formed in a polygonal cylinder shape such as a square tube shape, for example. In this case, the cylindrical part 42 is formed so as to oppose the shape of the convex part 22.

In the printed wiring board according to the first embodiment, the convex portion 22 and the cylindrical portion 42 formed by pressing the thick first surface side circuit pattern plate 20 and the second surface side circuit pattern plate 40 respectively. The thickness is large and a large current can flow. The convex part 22 and the cylindrical part 42 can be formed inexpensively by press working.

In the printed wiring board of the first embodiment, the first side circuit pattern board 20 and the second side circuit pattern board 40 are simultaneously formed by pressing together with the convex part 22 and the cylindrical part 42, The 1st surface side circuit pattern board 20 provided with the convex part 22 and the cylindrical part 42 and the 2nd surface side circuit pattern board 40 can be manufactured cheaply.

In the printed wiring board of the first embodiment, the convex portion 22 and the cylindrical portion 42 are connected by solder 60 interposed. In the step of mounting the electronic component 62 by reflowing the solder on the first surface side circuit pattern board 20 and the second surface side circuit pattern board 40, the solder may be poured between the convex portion 22 and the cylindrical portion 42. Since it can do, the convex part 22 and the cylindrical part 42 can be connected, without providing the process for a connection separately. In the first embodiment, solder is used as the low melting point metal. However, it is possible to make a connection with a silver paste or the like, or to use a conductive resin.

[Second Embodiment]
A printed wiring board according to a second embodiment of the present invention will be described with reference to FIG.
In the first embodiment described above, the convex portion 22 and the cylindrical portion 42 are electrically connected with solder interposed therebetween. However, in the second embodiment, the convex portion 22 and the cylindrical portion 42 are electrically connected by spot welding. Connect. In the second embodiment, the bottom portion 48 is provided in the cylindrical portion 42.

4A shows the first surface side circuit pattern board 20, the prepreg 30α, and the second surface side circuit pattern board 40. FIG. The first surface side circuit pattern plate 20 and the second surface side circuit pattern plate 40 are positioned so that the convex portion 22 and the cylindrical portion 42 correspond to each other, and an opening corresponding to the cylindrical portion 42 is interposed therebetween. The prepreg 30α having 32 formed is interposed.

The cylindrical portion 42 is fitted into the convex portion 22, the end portion 28 of the convex portion 22 is brought into contact with the bottom portion 48 of the cylindrical portion 42, and the first surface side circuit pattern plate 20 and the second surface side circuit pattern plate 40 are Is pressed and heated with a prepreg interposed therebetween, and the prepreg is thermoset to form the core resin layer 30. A through hole 34 for communicating the opening 24 of the first surface side circuit pattern board 20 and the opening 46 of the second surface side circuit pattern board 40 is formed in the core resin layer 30 (FIG. 4B). The spot welding electrode 70U is brought into contact with the end portion 28 of the convex portion 22 of the first surface side circuit pattern plate 20, and the spot welding electrode 70D is brought into contact with the bottom portion 48 of the cylindrical portion 42 of the second surface side circuit pattern plate 40. And a spot current is allowed to flow (FIG. 4C). Thereby, the end portion 28 of the convex portion 22 and the bottom portion 48 of the cylindrical portion 42 are melted, and the convex portion 22 of the first surface side circuit pattern board 20 and the cylindrical portion 42 of the second surface side circuit pattern board 40 are obtained. (FIG. 4D).

In the printed wiring board of 2nd Embodiment, the convex part 22 of the 1st surface side circuit pattern board 20 and the cylindrical part 42 of the 2nd surface side circuit pattern board 40 are connected by spot welding process. Although spot welding is used here, other welding methods such as arc welding, laser welding, and ultrasonic bonding can be used in addition to spot welding. Thereby, heat generation at the time of connection can be suppressed as compared with a case where a large current is passed using a high-resistance solder paste for interlayer connection.

FIG. 5 is an enlarged cross-sectional view showing a main part of a printed wiring board according to a modification of the second embodiment. As a modified example of the second embodiment, a recess 48a may be formed by cutting or the like on the bottom 48 as shown in FIG. 5A, or a seat press or the like as shown in FIG. 5B. The recess 48b may be provided by plastic processing. Thereby, positioning with the edge part 28 of the convex part 22 and the bottom part 48 of the cylindrical part 42 can be implemented more reliably.

Furthermore, as shown in FIG. 5C, a protrusion 48c may be provided on the surface of the recess 48b that faces the end 28. As a result, when joining (welding) by passing an electric current between the two members, the joining area is smaller than when joining the end faces of the end portion 28 and the bottom portion 48, so that the plate-like circuit having a large plate thickness Even when the patterns are bonded, the input current at the time of bonding can be suppressed to suppress heat generation.

[Third embodiment]
Next, a printed wiring board according to a third embodiment of the present invention will be described with reference to FIG. FIG. 6 is an enlarged cross-sectional view showing a main part of the printed wiring board 10 according to the third embodiment of the present invention. In FIG. 6, the solder 60 is omitted for convenience.

In the first embodiment described above, the interlayer connection is made by pouring the solder 60 between the convex portion 22 of the first surface side circuit pattern board 20 and the cylindrical portion 42 of the second surface side circuit pattern board 40. In the third embodiment, the interlayer connection is established by pouring the solder 60 between the outer surface (outer peripheral surface) of the convex portion 22 and the inner peripheral surface of the through hole 49 formed in the second surface side circuit pattern board 40. The

  Specifically, as shown in FIG. 6, the through hole 49 is formed so as to face the outer surface (outer peripheral surface) of the convex portion 22 on the inner peripheral surface with a predetermined gap therebetween. The outer surface of the protrusion 22 and the inner peripheral surface of the through hole 49 are electrically connected by an intervening solder 60.

As described above, the first surface side circuit pattern plate 20 and the second surface side circuit pattern plate 40 are electrically connected with a conductor cross-sectional area secured by the convex portions 22 and the through holes 49, and thus simplified. By connecting the front side and the back side of the printed wiring board with a simple configuration, a large current can flow. In particular, as the thickness of the second surface side circuit pattern plate 40 increases, the conductor cross-sectional area increases, and the circuit 60 can be reliably connected by the solder 60 interposing both the circuit pattern plates 20 and 40.

7 and 8 are enlarged cross-sectional views showing the main parts of a printed wiring board according to a modification of the third embodiment.
As a modification of the third embodiment, as shown in FIG. 7A, the convex portion 22b employed in place of the convex portion 22 may be formed so as to reduce in diameter toward the protruding side. Even in this case, the outer surface of the convex portion 22 b and the inner peripheral surface of the through hole 49 can be electrically connected by the solder 60.

Further, as shown in FIG. 7B, the convex portion 22c employed in place of the convex portion 22 is bent in an L shape from the protruding piece 23a protruding toward the through hole 49 and the distal end portion of the protruding piece 23a. It may be formed so as to have a conductive portion 23b formed. The conductive portion 23b is formed so as to face the inner peripheral surface of the through hole 49 at a peripheral edge with a predetermined gap. Even in this case, it is possible to electrically connect the outer edge of the conductive portion 23b and the inner peripheral surface of the through hole 49 by the solder 60 interposed.

Moreover, as shown to FIG. 8 (A), the cylindrical part 49a may be formed so that it may hang down from the internal peripheral surface of the through-hole 49 shown in FIG. Further, as shown in FIGS. 8B and 8C, a cylindrical portion 49a is formed so as to hang down from the inner peripheral surface of the through hole 49 shown in FIGS. 7A and 7B. May be.

[Fourth embodiment]
Next, a printed wiring board according to a fourth embodiment of the present invention will be described with reference to FIG.
In the first embodiment described above, the core resin layer 30 is formed by thermosetting the prepreg 30α in a state where the cylindrical portion 42 is fitted into the convex portion 22, but in the fourth embodiment, as shown in FIG. In addition, a core resin layer 30b that has been cured in advance is prepared, and the first surface side circuit pattern board 20 and the second surface side circuit pattern board 40 are fixed to the core resin layer 30b by an adhesive 80 and the convex portion 22 is fixed. A cylindrical portion 42 is fitted into the base.

The core resin layer 30b in the fourth embodiment is configured by curing a prepreg in which a core material such as glass cloth is impregnated with a resin such as epoxy in advance, and the thickness thereof is, for example, 0.4 to 4.0 mm. More preferably, it is set to 0.5 to 0.8 mm.

Further, as the adhesive 80, a silicone-based adhesive is adopted in consideration of stretchability and the like in addition to adhesiveness, thermal conductivity, and insulation, and the thickness thereof is 100 μm or less, more preferably 40 to 50 μm. Is set to As described above, the adhesive 80 is not limited to the silicone-based adhesive, but may be an epoxy-based adhesive with an emphasis on the adhesive strength, for example, or the adhesive strength and the heat resistance. Then, a polyimide-based adhesive may be employed. A prepreg may be used as the adhesive 80.

Thus, since the 1st surface side circuit pattern board 20 and the 2nd surface side circuit pattern board 40 are fixed to the core resin layer 30b with the adhesive agent 80, when providing a circuit pattern on an insulating layer by film-forming etc. As compared with the circuit board, both the circuit pattern plates 20 and 40 can be easily increased in thickness, and the circuit board molding time can be shortened.

In particular, since the adhesive 80 is a silicone-based adhesive and has high stretchability compared to other adhesives, even when both circuit pattern plates 20 and 40 are deformed due to residual stress at the time of circuit pattern molding, It is possible to eliminate the peeling of the adhesive 80 and the damage of the circuit pattern plates 20 and 40.

As a first modification of the fourth embodiment, as the core resin layer 30b and the adhesive 80, a core material having higher heat dissipation than a resin layer or the like usually employed as an insulating layer, for example, part or all of which is a metal You may employ | adopt the core material and the adhesive agent with high insulation. As a result, the core material employed in place of the core resin layer 30b does not require insulation, so a member with higher heat dissipation can be employed as the core material.

As a second modification of the fourth embodiment, instead of the core resin layer 30b and the adhesive 80, a member (for example, a metal member such as copper) having adhesiveness and having one or a plurality of heat dissipation properties therein is used. An insulating layer that is included and configured may be employed. Thereby, it is not necessary to apply an adhesive or the like, and the heat dissipation of the insulating layer can be enhanced by the member having the heat dissipation inside.

FIG. 10 is an enlarged cross-sectional view showing a main part of a printed wiring board according to third to fifth modifications of the fourth embodiment. As a third modification of the fourth embodiment, as shown in FIG. 10A, the cylindrical portion 42 is eliminated and a bottom portion 48 is adopted, and a concave portion 48a is formed on the bottom portion 48 by cutting or the like. May be. Further, as a fourth modification of the fourth embodiment, as shown in FIG. 10B, a recess 48b may be provided by plastic working such as seating against FIG. 10A. Thereby, positioning of the edge part 28 and the bottom part 48 of the convex part 22 can be implemented, without providing the cylindrical part 42. FIG.

Furthermore, as a fifth modification of the fourth embodiment, a protrusion 48c may be provided on the surface of the recess 48b that faces the end 28 as shown in FIG. 10C. As a result, when joining (welding) by passing an electric current between the two members, the joining area is smaller than when joining the end faces of the end portion 28 and the bottom portion 48, so that the plate-like circuit having a large plate thickness Even when the patterns are bonded, the input current at the time of bonding can be suppressed to suppress heat generation.

The present invention is not limited to the above embodiments, and may be embodied as follows. Even in this case, the same operations and effects as those of the above embodiments can be obtained.
(1) FIG. 11 is an enlarged cross-sectional view showing a main part of a printed wiring board according to a first modification of the first embodiment. As a first modification of the first embodiment, as shown in FIG. 11, the end portion 42 a of the cylindrical portion 42 of the second surface side circuit pattern board 40 may be formed so as to increase in diameter toward the tip. Thereby, the fitting operation | work of the cylindrical part 42 with respect to the convex part 22d can be made easy. In the second embodiment and the third embodiment, the same effects can be obtained. In addition, the convex part 22d may be formed so that the diameter may be reduced toward the tip as shown in FIG.

(2) FIGS. 12A to 12C are enlarged cross-sectional views showing the main parts of a printed wiring board according to a second modification of the first embodiment. As a second modification of the first embodiment, as shown in FIG. 12A, the end 42b of the cylindrical portion 42 of the second surface side circuit pattern board 40 is formed to be curved inward. Also good. Further, as shown in FIG. 12B, the cylindrical portion 42c itself may be formed to be bent outward. Further, as shown in FIG. 12C, the cylindrical portion 42d itself may be formed to be curved inward. Even in this way, the fitting operation of the cylindrical portions 42, 42c, and 42d into the convex portion 22d can be facilitated as in the first modification. In the second embodiment and the third embodiment, the same effects can be obtained.

(3) FIG. 13 is an enlarged cross-sectional view showing a main part of a printed wiring board according to a third modification of the first embodiment. As a third modification of the first embodiment, as shown in FIG. 13, a protrusion 22e is formed on the outer peripheral surface of the convex portion 22 of the first surface side circuit pattern board 20, and the protrusion 22e is made to correspond to the protrusion 22e. A recess 42e may be formed on the inner peripheral surface of the cylindrical portion 42 of the second surface side circuit pattern board 40. As a result, the contact area between the solder 60 and the convex portion 22 and the cylindrical portion 42 is increased, so that the first surface side circuit pattern plate 20 and the second surface side circuit pattern plate 40 are reliably electrically connected. Can do.

(4) The circuit board 10 is not limited to being used for large currents, but may be used for fine currents (for example, several mA).

DESCRIPTION OF SYMBOLS 10 Printed wiring board 20 1st surface side circuit pattern board 22 Convex part 30,30b Core resin layer 40 2nd surface side circuit pattern board 42 Cylindrical part 50U Upper die 50D Lower die 60 Solder 80 Adhesive

Claims (11)

A printed wiring board comprising a resin layer and a first surface side plate-like circuit pattern and a second surface side plate-like circuit pattern facing each other through the resin layer,
The first surface side plate circuit pattern and the second surface side plate circuit pattern are provided on one side of the first surface side plate circuit pattern or the second surface side plate circuit pattern, and on the other side. A printed wiring board, wherein the printed wiring board is electrically connected by a facing portion facing the outer surface of the projected portion.   The printed wiring board according to claim 1, wherein the facing portion is formed in a cylindrical shape so as to be fitted into an outer periphery of the convex portion.   The printed wiring board according to claim 1, wherein the convex portion and the facing portion are each formed by press working.   The said 1st surface side plate-shaped circuit pattern and the said 2nd surface side plate-shaped circuit pattern are simultaneously formed by press work with the said convex part and the said opposing part, The Claim 1 or 2 characterized by the above-mentioned. Printed wiring board.   The printed wiring board according to claim 1, wherein the printed wiring board is electrically connected via a low-melting-point metal in which the convex portion and the facing portion are interposed.   The printed wiring board according to claim 1, wherein the convex portion and the facing portion are electrically connected by bonding.   The printed wiring board according to claim 1, wherein a concave portion that engages with a part of the convex portion is formed on a joint surface of the facing portion.   The printed circuit board according to claim 1, wherein the first surface side plate-like circuit pattern and the second surface side plate-like circuit pattern are fixed to the resin layer with an adhesive.   The printed wiring board according to claim 8, wherein the adhesive is a silicone-based adhesive.   The printed wiring board according to claim 8 or 9, wherein a core material having a high heat dissipation property and an adhesive having a high insulating property are adopted as the resin layer and the adhesive.   11. The insulating layer configured to include an adhesive member having one or a plurality of heat dissipation properties instead of the resin layer and the adhesive is employed. The printed wiring board as described in any one.

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