JP2011077420A - Method of manufacturing printed wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a printed wiring board that can have a one surface-side plate-like circuit pattern and an other surface-side plate-like circuit pattern electrically connected to make a large current flow between both the circuit patterns. <P>SOLUTION: In the method of manufacturing the printed wiring board, a top surface-side circuit pattern 20 having a first protrusion 21 and a projection 22 is formed, and a reverse surface-side circuit pattern 40 having a second protrusion 41 is formed. In a state that the projection 22 and a protrusion-side end surface 41a of the second protrusion 41 are inserted into an insertion hole 31 formed at an insulating layer 30 from different directions to abut against each other, the top surface-side circuit pattern 20 and the reverse surface-side circuit pattern 40 are laminated together with the insulating layer 30. Then the projection 22 and the protrusion-side end surface 41a are electrically connected by resistance welding. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a printed wiring board that can be suitably used for a substrate for large currents such as a control substrate of a high-output motor of an electric vehicle or a hybrid vehicle.

  Conventionally, as a technique related to a printed wiring board that can be suitably used for a high-current compatible board such as a control board of a high output motor of an electric vehicle or a hybrid vehicle, a method for manufacturing a printed wiring board shown in Patent Document 1 below is known. Yes. In this method of manufacturing a printed wiring board, through holes are provided in a base material provided with a copper foil for forming a wiring pattern on both surfaces, and the through paste is filled and cured with a conductive paste. Interlayer conduction is established by electrically connecting the copper foils on both sides via a conductive paste.

  Moreover, in the multilayer laminated wiring board shown in the following Patent Document 2, a through hole is formed in order to establish electrical conduction between the front and back surfaces of the insulating substrate, and a conductive metal piece must exist in the through hole. Thus, the wiring pattern formed on the front surface of the insulating substrate and the wiring pattern formed on the back surface are electrically connected. This conductive metal piece is formed by placing the conductive metal foil on the surface of the insulating substrate and punching the conductive metal foil and the insulating substrate at the same time using a punch. Is formed.

  Further, in the method for manufacturing a wiring board shown in Patent Document 3 below, an interlayer connection portion is formed in the wiring pattern of one lead frame, and a portion of the wiring pattern of the other lead frame is joined to the interlayer connection portion. Print the solder. Then, both lead frames are superposed and heat-treated so that the interlayer connection portion is bonded to the lower surface of the other wiring pattern via solder. As a result, the wiring patterns of both lead frames are electrically interconnected via the interlayer connection portion to achieve interlayer conduction.

  In addition, in the method of manufacturing a wiring board shown in Patent Document 3 below, a conductive ball having a structure in which a solder layer is coated on the surface of a copper ball is prepared, and the conductive ball is disposed in a concave portion of the wiring pattern of one lead frame. After that, the conductive ball solder layer is bonded to one wiring pattern by heat treatment. Then, both lead frames are superposed and heat-treated so that the conductive balls are bonded to the lower surface of the other wiring pattern. As a result, the wiring patterns of both lead frames are electrically interconnected via the conductive balls to achieve interlayer conduction.

Japanese Patent Laid-Open No. 11-074640 JP 2005-243911 A JP 2008-182163 A

  However, as in the inventions described in the above Patent Documents 1 to 3, it is necessary to prepare a member (conductive paste, metal piece, solder, conductive ball, etc.) other than the pattern in order to obtain interlayer conduction. A process is required, which hinders manufacturing cost reduction. In addition, when a conductive paste or the like is used to obtain interlayer conduction between copper patterns, there is a problem of loss and heat generation because the electric resistance is larger than the pattern.

  The present invention has been made in order to solve the above-described problems. The object of the present invention is to electrically connect the one-side plate circuit pattern and the other-side plate circuit pattern between the two circuit patterns. An object of the present invention is to provide a method for manufacturing a printed wiring board capable of flowing a large current.

  In order to achieve the above object, in the printed wiring board manufacturing method according to claim 1, the printed wiring board manufactured by interposing the one-side plate circuit pattern and the other-side plate circuit pattern with an insulating layer interposed therebetween. A method for manufacturing a plate, comprising: forming a one-side plate-like circuit pattern having a first projecting portion projecting in a bottomed cylindrical shape and a projecting portion projecting from a part of a projecting side end surface of the first projecting portion. 1st process, 2nd process of forming the said other surface side plate-shaped circuit pattern which has the 2nd protrusion part which protrudes in a bottomed cylindrical shape, The protrusion part of the said 1st protrusion part, and the protrusion side of the said 2nd protrusion part A third step of laminating the one-surface side plate-like circuit pattern and the other-surface-side plate-like circuit pattern together with the insulating layer in a state where the end surface is inserted and brought into contact with the insertion hole provided in the insulating layer from different directions. And the protrusion and Characterized in that it comprises a fourth step of electrically connecting by resistance welding the second projecting portion.

  According to a second aspect of the present invention, in the method for manufacturing a printed wiring board according to the first aspect, an annular shape is provided on the protruding side end face of the second protruding portion and in the vicinity of the outer edge thereof, surrounding the contact portion with the protruding portion. A convex portion is formed.

  According to a third aspect of the present invention, in the method for manufacturing a printed wiring board according to the first or second aspect, the first step is performed with respect to the first projecting portion, the projecting portion, and the projecting side of the first projecting portion. Forming the one-side plate-like circuit pattern having a first heat transfer portion protruding in the vicinity of the first protrusion to the opposite side, and the fourth step includes the first heat transfer portion exposed from the insulating layer. The resistance welding is performed in a state where the first heat radiating member is in contact therewith.

  According to a fourth aspect of the present invention, in the method for manufacturing a printed wiring board according to the third aspect, the first heat transfer section is formed to protrude so as to surround the first protrusion.

  According to a fifth aspect of the present invention, in the method for manufacturing a printed wiring board according to the third or fourth aspect, in the vicinity of the first heat transfer section, the heat transfer is exposed from the insulating layer and can contact the first heat radiating member. A plurality of heat parts are formed.

  Invention of Claim 6 is a manufacturing method of the printed wiring board as described in any one of Claims 1-5. WHEREIN: A said 2nd process is with respect to the 2nd protrusion part and the protrusion side of the said 2nd protrusion part. And forming the other surface side plate-like circuit pattern having a second heat transfer portion projecting in the vicinity of the second projecting portion to the opposite side, and the fourth step includes exposing the second transfer surface exposed from the insulating layer. The resistance welding is performed in a state in which the second heat radiating member is in contact with the hot part.

  The invention according to claim 7 is the method for manufacturing a printed wiring board according to claim 6, wherein the second heat transfer portion is formed to protrude so as to surround the second protrusion.

  An eighth aspect of the present invention is the method for manufacturing a printed wiring board according to the sixth or seventh aspect, wherein the second heat transfer portion is exposed near the second heat transfer portion and exposed from the insulating layer so as to be in contact with the second heat radiating member. A plurality of heat parts are formed.

  According to the first aspect of the present invention, there is provided a one-side plate-like circuit pattern having a first projecting portion projecting into a bottomed cylindrical shape and a projecting portion projecting from a part of the projecting side end surface of the first projecting portion. It is formed. And the other surface side plate-shaped circuit pattern which has the 2nd protrusion part which protrudes in a bottomed cylinder shape is formed by a 2nd process. Then, in the third step, the one-side plate-like shape in a state where the protruding portion of the first protruding portion and the protruding side end surface of the second protruding portion are inserted and brought into contact with the insertion hole provided in the insulating layer from different directions. The circuit pattern and the other side plate-like circuit pattern are laminated together with the insulating layer. In the fourth step, the protrusion and the second protrusion are electrically connected by resistance welding.

As a result, the one-surface-side plate-like circuit pattern and the other-surface-side plate-like circuit pattern are electrically connected via the first projecting portion and the second projecting portion without using a connection member having a large resistance value. Therefore, the loss and heat generation in the obtained connection portion are suppressed, and a large current can be passed between both circuit patterns in accordance with the plate thicknesses of both protruding portions. In addition, since the first projecting portion and the second projecting portion are joined by resistance welding to obtain interlayer conduction, the cost can be reduced as compared with the case of interlayer conduction by laser welding or ultrasonic joining. In particular, since the protrusion of the first protrusion and the protrusion-side end face of the second protrusion are resistance-welded, the joint area is smaller than when the protrusion-side end faces are resistance-welded to each other. Even when resistance-like circuit patterns are resistance-welded, the input current at the time of joining can be suppressed to suppress heat generation. For this reason, it is possible to reduce the influence on the insulating layer, the mounted component, and the like due to the deformation of the circuit pattern caused by the heat generated during the bonding.
Therefore, it is possible to manufacture a printed wiring board that can electrically connect the one-side circuit pattern and the other-side circuit pattern to allow a large current to flow between the two circuit patterns.

  In the invention of claim 2, since an annular convex portion is formed on the projecting side end surface of the second projecting portion and in the vicinity of the outer edge thereof so as to surround the contact portion with the projecting portion of the first projecting portion. Even when the outer edge of the projecting side end surface of the first projecting part deforms to the second projecting part side with the projecting part as a base point, the outer edge of the first projecting part comes into contact with the annular projecting part. it can.

  In the invention of claim 3, in the first step, the first projecting portion and the projecting portion, and the first heat transfer portion projecting in the vicinity of the first projecting portion to the opposite side to the projecting side of the first projecting portion. A one-side plate circuit pattern is formed so as to have And by 4th process, resistance welding is implemented in the state which made the 1st heat radiating member contact the 1st heat-transfer part exposed from an insulating layer.

  As a result, heat generated when resistance-welding the projecting portion of the first projecting portion and the projecting side end surface of the second projecting portion is transferred to the first heat radiating member via the first heat transfer portion. The influence of the heat generated by resistance welding on the insulating layer and the mounted parts can be reliably suppressed.

  In the invention of claim 4, since the first heat transfer portion is formed so as to surround the first protrusion, the heat transfer is close to the first protrusion and has a large contact area with the first heat radiating member. Since the part can be provided, the heat generated by the resistance welding can be effectively transmitted to the first heat radiating member via the first heat transfer part.

  In the invention of claim 5, since a plurality of heat transfer portions that are exposed from the insulating layer and can contact the first heat radiating member are formed in the vicinity of the first heat transfer portion, a heat transfer path to the first heat radiating member is provided. Since there are multiple, the influence of the heat generated by the resistance welding on the insulating layer, the mounted component, and the like can be more reliably suppressed.

  In the invention of claim 6, the second step includes a second projecting portion and a second heat transfer portion projecting in the vicinity of the second projecting portion to the opposite side to the projecting side of the second projecting portion. Thus, the other side plate-like circuit pattern is formed. And by 4th process, resistance welding is implemented in the state which made the 2nd heat radiating member contact the 2nd heat-transfer part exposed from an insulating layer.

  As a result, heat generated when resistance welding the protrusion of the first protrusion and the protrusion-side end surface of the second protrusion is transferred to the second heat radiating member via the second heat transfer portion. The influence of the heat generated by resistance welding on the insulating layer and the mounted parts can be reliably suppressed.

  In the invention of claim 7, since the second heat transfer portion is formed to protrude so as to surround the second protrusion, the heat transfer is close to the second protrusion and has a large contact area with the second heat radiating member. Since the part can be provided, the heat generated by the resistance welding can be effectively transmitted to the second heat radiating member via the second heat transfer part.

  In the invention of claim 8, since a plurality of heat transfer portions that are exposed from the insulating layer and can contact the second heat radiating member are formed in the vicinity of the second heat transfer portion, a heat transfer path to the second heat radiating member is provided. Since there are multiple, the influence of the heat generated by the resistance welding on the insulating layer, the mounted component, and the like can be more reliably suppressed.

It is sectional drawing which shows schematic structure of the printed wiring board 10 which concerns on 1st Embodiment. It is process drawing which shows a part of manufacturing process of the printed wiring board 10 which concerns on 1st Embodiment. It is process drawing which shows a part of manufacturing process of the printed wiring board 10 which concerns on 1st Embodiment. It is process drawing which shows a part of manufacturing process of the printed wiring board 10 which concerns on 1st Embodiment. It is process drawing which shows a part of manufacturing process of the printed wiring board 10 which concerns on 1st Embodiment. It is sectional drawing which shows the principal part of the manufacturing process of the printed wiring board 10 which concerns on 2nd Embodiment. It is sectional drawing which shows the principal part of the manufacturing process of the printed wiring board 10 which concerns on the 1st modification of 2nd Embodiment. It is sectional drawing which shows the principal part of the manufacturing process of the printed wiring board 10 which concerns on the 2nd modification of 2nd Embodiment.

[First Embodiment]
Hereinafter, a method for manufacturing a printed wiring board according to a first embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, the printed wiring board 10 is configured by laminating a plate-like surface side circuit pattern 20 and a back surface side circuit pattern 40 on an insulating layer 30 from an upper surface side and a lower surface side.

  The front-side circuit pattern 20 and the back-side circuit pattern 40 are configured by punching and pressing a predetermined pattern on a copper plate having a thickness of 0.5 to 2.0 mm, for example. In the first embodiment, a metal plate having a predetermined thickness is used instead of a metal foil as a plate-like circuit pattern that can handle a large current (for example, 50 to 180 A). Here, the metal plate defined in the first embodiment means a plate-like body that can be punched and can maintain the shape without applying an external force such as tension, and has a shape of itself that performs etching. It is a concept that excludes metal foil that cannot be maintained.

  The front-side circuit pattern 20 is formed with a first protruding portion 21 that protrudes in a bottomed cylindrical shape, and the back-side circuit pattern 40 is formed with a second protruding portion 41 that protrudes in a bottomed cylindrical shape. Yes. The projections 21 and 41 are inserted from different directions into the insertion hole 31 provided in the insulating layer 30 and are provided as projections for resistance welding at the center of the projection-side end surface 21a of the first projection 21. 22 and the projecting side end surface 41a of the second projecting portion 41 are electrically connected to each other, so that interlayer connection between both circuit patterns 20 and 40 is established. The front-side circuit pattern 20 and the back-side circuit pattern 40 correspond to an example of “one-side plate circuit pattern and other-side plate circuit pattern” recited in the claims.

  The insulating layer 30 is formed by laminating a plurality of prepregs in which a core material such as a glass cloth is impregnated with a resin such as epoxy, and the thickness thereof is set to 0.5 to 4.0 mm, for example. Yes.

Next, the manufacturing process of the printed wiring board 10 of the first embodiment will be described with reference to FIGS.
First, as shown in FIG. 2A, a copper plate 20a having a predetermined shape as a material is prepared. Then, as shown in FIGS. 2 (B) and 2 (C), the surface-side circuit pattern 20 having the first protrusions 21 and the projections 22 and the first protrusions 23 described above is pressed into a press die according to a predetermined pattern. Batch forming is performed by pressing using 51U and 51D. 2A to 2C correspond to an example of the “first step” described in the claims, and the projection 22 corresponds to the “projection portion” described in the claims. It corresponds to an example.

  Here, the first projection 23 is formed to project in an annular shape so as to surround the first projection 21 on the opposite side to the projection side of the first projection 21. For example, the first protrusion 23 is set to have a width dimension of 0.5 mm and a height dimension of 0.2 mm.

  2A to 2C, the first protrusion 21, the projection 22 and the first protrusion 23 are simultaneously formed together with the predetermined pattern. Thereby, compared with the case where each site | part is shape | molded separately, manufacturing cost can be reduced.

  Next, as shown in FIG. 3A, a copper plate 40a having a predetermined shape as a material is prepared. Then, as shown in FIGS. 3B and 3C, the back side circuit pattern 40 having the second protrusion 41, the second protrusion 42, and the annular protrusion 43 described above is formed in accordance with a predetermined pattern. Batch forming is performed by press working using the press dies 52U and 52D. The steps shown in FIGS. 3A to 3C correspond to an example of “second step” described in the claims.

  Here, the second protrusion 42 is formed to project in an annular shape so as to surround the second protrusion 41 on the opposite side to the protrusion side of the second protrusion 41. Further, the annular convex portion 43 is formed on the protruding side end surface 41a and in the vicinity of the outer edge so as to surround a contact portion that contacts the projection 22 as will be described later. For example, the second protrusion 42 has a width dimension set to 0.5 mm and a height dimension set to 0.2 mm.

  3A to 3C, the second protrusion 41 and the second protrusion 42 are simultaneously formed together with the predetermined pattern. Thereby, compared with the case where each site | part is shape | molded separately, manufacturing cost can be reduced.

  Next, as shown in FIG. 4A, a prepreg 30a in which an insertion hole 31 is formed and prepregs 30b and 30c for the outermost layer are prepared, and the projection 22 of the first protrusion 21 and the second protrusion 41 are formed. The projecting side end surface 41a is inserted into contact with the insertion hole 31 from a different direction. The prepregs 30a to 30c are each formed by stacking a plurality of thin film prepregs in the first embodiment, but may be formed by a single prepreg.

  Subsequently, as shown in FIG. 4B, the anti-insulating layer side of the front-side circuit pattern 20 and the anti-insulating layer side of the back-side circuit pattern 40 are pressed with an upper die 53U and a lower die 53D by pressing or the like. -Heat. Thereby, the prepregs 30a to 30c are thermally cured to form the insulating layer 30, and the circuit patterns 20 and 40 and the insulating layer 30 are laminated in a state where the projection 22 and the projecting side end surface 41a are in contact with each other. Become. The steps shown in FIGS. 4A and 4B correspond to an example of “third step” described in the claims.

  At this time, since the first protrusion 23 and the second protrusion 42 are directly pressed against the upper mold 53U and the lower mold 53D, the resin or the like in the vicinity of the upper mold 53U and the lower mold 53D exceeds the annular protrusions 23, 42. Thus, it is possible to prevent the first projecting portion 21 and the second projecting portion 41 from flowing into the inner peripheral side.

  Next, as shown in FIG. 5, the projection 22 of the first projecting portion 21 and the projecting side end surface 41a of the second projecting portion 41 are electrically connected by performing resistance welding using welding electrodes 61U and 61D. To do. Thereby, the printed wiring board 10 shown in FIG. 1 is completed. The process shown in FIG. 5 corresponds to an example of a “fourth process” recited in the claims.

  At this time, since the projection 22 of the first projecting portion 21 and the projecting side end surface 41a of the second projecting portion 41 are resistance-welded, the joint area is smaller than that when the projecting-side end surfaces are resistance-welded. Even when the thick plate-like circuit patterns 20 and 40 are resistance-welded, the input current at the time of joining can be suppressed and heat generation can be suppressed.

  In addition, the annular protrusion 43 is formed on the protrusion side end surface 41a so as to surround a contact portion that contacts the projection 22 in the vicinity of the outer edge thereof, so that the protrusion side of the first protrusion 21 is formed during resistance welding. Even when the outer edge of the end surface 21a is deformed to the second projecting portion side with the projection 22 as a base point, the outer surface abuts the annular projecting portion 43, so that deformation of the first projecting portion 21 can be limited. In addition, the resin etc. of the insertion hole 31 vicinity are cyclic | annular by forming the annular convex part 43 so that it may contact | abut to the outer edge vicinity of the protrusion side end surface 21a of the 1st protrusion part 21 at the time of lamination | stacking shown in FIG.4 (B). You may suppress flowing in between projection 22 and the protrusion side end surface 41a beyond the convex part 43. FIG.

  As described above, in the method for manufacturing the printed wiring board 10 according to the first embodiment, the surface-side circuit pattern 20 having the first protrusions 21 and the projections 22 is formed by the process shown in FIG. And the back surface side circuit pattern 40 which has the 2nd protrusion part 41 is formed of the process shown in FIG. Then, by the process shown in FIG. 4, the projection 22 and the projecting side end surface 41 a of the second projecting portion 41 are inserted into and contacted with the insertion hole 31 provided in the insulating layer 30 from different directions. The circuit pattern 20 and the back side circuit pattern 40 are laminated together with the insulating layer 30. And the projection 22 and the protrusion side end surface 41a are electrically connected by resistance welding by the process shown in FIG.

Thereby, the front surface side circuit pattern 20 and the back surface side circuit pattern 40 are electrically connected via the first protrusion 21 and the second protrusion 41 without using a connection member having a large resistance value. As a result, the loss and heat generation in the connection portion are suppressed, and a large current can be passed between the circuit patterns 20 and 40 in accordance with the plate thicknesses of the protrusions 21 and 41. Moreover, since both the protrusion parts 21 and 41 are joined by resistance welding and interlayer conduction is taken, cost reduction can be achieved compared with the case where interlayer welding is taken by laser welding or ultrasonic joining. In particular, since the projection 22 and the projecting side end surface 41a of the second projecting portion 41 are resistance-welded, the joint area is smaller than when the projecting-side end surfaces 21a and 41a are resistance-welded to each other. Even when resistance-like circuit patterns are resistance-welded, the input current at the time of joining can be suppressed to suppress heat generation. For this reason, it is possible to reduce the influence on the insulating layer 30 and the mounted component due to the deformation of the circuit patterns 20 and 40 caused by the heat generated during the bonding.
Therefore, the printed wiring board 10 capable of flowing a large current between the circuit patterns 20 and 40 by electrically connecting the front-side circuit pattern 20 and the back-side circuit pattern 40 can be manufactured. In particular, since no separate member is used for interlayer connection, the number of parts can be reduced and the cost can be reduced.

  In the method for manufacturing the printed wiring board 10 according to the first embodiment, since the annular protrusion 43 is formed on the protrusion-side end surface 41a of the second protrusion 41, the protrusion of the first protrusion 21 is caused during resistance welding. Even when the outer edge of the side end face 21a is deformed to the second projecting portion side with the projection 22 as a base point, the outer end abuts on the annular projecting portion 43, so that deformation of the first projecting portion 21 during resistance welding can be limited.

[Second Embodiment]
Next, a method for manufacturing a printed wiring board according to the second embodiment of the present invention will be described with reference to FIG.
In the method for manufacturing the printed wiring board 10 according to the second embodiment, the first heat dissipating member 62U and the second heat dissipating member 62D are newly employed. The method for manufacturing the printed wiring board according to the first embodiment is as follows. And different. Therefore, substantially the same components as those of the printed wiring board manufacturing method of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In the second embodiment, during the resistance welding described above, as shown in FIG. 6, the first heat radiating member 62 </ b> U is brought into contact with the first protrusion 23 exposed upward from the insulating layer 30 and exposed downward from the insulating layer 30. The resistance welding described above is performed in a state where the second heat radiation member 62D is in contact with the second protrusion 42 to be performed.

  As a result, the heat generated when resistance welding is performed between the projection 22 of the first protrusion 21 and the protrusion-side end surface 41a of the second protrusion 41 via the first protrusion 23 and the second protrusion 42 in the vicinity of the welded portion. Heat is transferred to the first heat radiating member 62U and the second heat radiating member 62D (see arrow α in FIG. 6). Thus, since the 1st protrusion 23 and the 2nd protrusion 42 function as a heat-transfer part, the influence on the insulating layer 30 or mounting components by the heat_generation | fever of the said resistance welding can be suppressed reliably. The first protrusion 23 and the second protrusion 42 correspond to an example of “first heat transfer section and second heat transfer section” recited in the claims.

  In the second embodiment, since the first protrusion 23 is formed so as to surround the first protrusion 21, it is close to the first protrusion 21 and is in contact with the first heat radiating member 62 </ b> U. Therefore, the heat generated by the resistance welding can be effectively transmitted to the first heat radiating member 62U via the first protrusion 23.

  Furthermore, in the second embodiment, since the second protrusion 42 is formed so as to surround the second protrusion 41, the second protrusion 42 is close to the second protrusion 41 and is in contact with the second heat radiating member 62 </ b> D. Therefore, the heat generated by the resistance welding can be effectively transmitted to the second heat radiating member 62D via the second protrusion 42.

  As a first modification according to the second embodiment, as shown in FIG. 7, a first protrusion 23 a and a second protrusion 42 a may be employed instead of the first protrusion 23 and the second protrusion 42. The first protrusion 23 a is formed to protrude in the vicinity of the first protrusion 21 toward the opposite side to the protrusion side of the first protrusion 21, and the second protrusion 42 a is a protrusion of the second protrusion 41. It is formed so as to protrude in the vicinity of the second protrusion 41 to the opposite side to the side. Even if it does in this way, the heat transfer path | route to 62 U of 1st heat radiating members and 62D of 2nd heat radiating members is ensured, and the influence on the insulating layer 30 or mounting components by the heat_generation | fever of the said resistance welding can be suppressed.

  As a second modification according to the second embodiment, as shown in FIG. 8, the first heat radiating member 62U and the second heat radiating member 62D are exposed from the insulating layer 30 in the vicinity of the first protrusion 23 and the second protrusion 42. A plurality of heat transfer portions 25 and 44 that can contact each other may be formed. Thereby, since there are a plurality of heat transfer paths to the first heat radiating member 62U and the second heat radiating member 62D, it is possible to more reliably suppress the influence of the heat generated by the resistance welding on the insulating layer 30 and the mounted components. .

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) In each of the above embodiments, the projection 22 is not limited to being provided at the center on the protruding side end surface 21 a of the first protruding portion 21, but may be provided at a position where the welding operation can be easily performed. Alternatively, the projection 22 of the first protrusion 21 may be eliminated and a protrusion corresponding to the projection 22 may be provided on the protrusion-side end surface 41 a of the second protrusion 41.

(2) In the second embodiment, if the amount of heat generated during resistance welding is small, only the first protrusion 23 is brought into contact with the first heat radiating member 62U or only the second protrusion 42 is connected to the second heat radiating member. You may implement the said resistance welding in the state made to contact 62D.

10 ... Printed wiring board 20 ... Front side circuit pattern (one side side plate circuit pattern, other side side plate circuit pattern)
21 ... 1st protrusion part 21a ... Projection side end surface 22 ... Projection (protrusion part)
23 ... 1st protrusion (1st heat-transfer part)
DESCRIPTION OF SYMBOLS 30 ... Insulating layer 30a, 30b, 30c ... Prepreg 31 ... Insertion hole 40 ... Back surface side circuit pattern (one surface side plate circuit pattern, other surface side plate circuit pattern)
41 ... 2nd protrusion part 41a ... protrusion side end surface 42 ... 2nd protrusion (2nd heat-transfer part)
43 ... annular projection 61U, 61D ... welding electrode 62U ... first heat radiation member 62D ... second heat radiation member

Claims (8)

A method for producing a printed wiring board produced by interposing an insulating layer on one side plate-like circuit pattern and another side plate-like circuit pattern,
A first step of forming the one-surface-side plate-like circuit pattern having a first projecting portion projecting in a bottomed cylindrical shape and a projecting portion projecting from a part of the projecting side end surface of the first projecting portion;
A second step of forming the other surface side plate-like circuit pattern having a second projecting portion projecting into a bottomed cylindrical shape;
The one-surface-side plate-like circuit pattern in a state in which the protrusions of the first protrusions and the protrusion-side end surfaces of the second protrusions are inserted and brought into contact with insertion holes provided in the insulating layer from different directions. And a third step of laminating the other side plate circuit pattern together with the insulating layer,
A fourth step of electrically connecting the protrusion and the second protrusion by resistance welding;
A method for manufacturing a printed wiring board, comprising:   2. The printed wiring board according to claim 1, wherein an annular convex portion is formed on the projecting side end surface of the second projecting portion and in the vicinity of an outer edge thereof so as to surround a contact portion with the projecting portion. Production method. The first step includes the first projecting portion, the projecting portion, and a first heat transfer section projecting in the vicinity of the first projecting portion to the opposite side to the projecting side of the first projecting portion. Form a one-side plate circuit pattern,
3. The printed wiring according to claim 1, wherein in the fourth step, the resistance welding is performed in a state where a first heat radiating member is in contact with the first heat transfer portion exposed from the insulating layer. A manufacturing method of a board.   4. The method of manufacturing a printed wiring board according to claim 3, wherein the first heat transfer portion is formed to protrude so as to surround the first protrusion. 5.   5. The printed wiring board according to claim 3, wherein a plurality of heat transfer portions that are exposed from the insulating layer and are in contact with the first heat radiating member are formed in the vicinity of the first heat transfer portion. Manufacturing method. The second surface side plate-like shape having the second projecting portion and a second heat transfer portion projecting in the vicinity of the second projecting portion to the opposite side to the projecting side of the second projecting portion. Forming a circuit pattern,
The said 4th process implements the said resistance welding in the state which made the 2nd heat radiating member contact the said 2nd heat transfer part exposed from the said insulating layer, The said any one of Claims 1-5 characterized by the above-mentioned. The manufacturing method of the printed wiring board as described in 1 ..   The method for manufacturing a printed wiring board according to claim 6, wherein the second heat transfer portion is formed to protrude so as to surround the second protrusion.   8. The printed wiring board according to claim 6, wherein a plurality of heat transfer portions that are exposed from the insulating layer and are in contact with the second heat radiating member are formed in the vicinity of the second heat transfer portion. Manufacturing method.

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