JP2015170632A - Composite wiring board and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite wiring board having high production efficiency and a manufacturing method of the composite wiring board.SOLUTION: In a composite wiring board 100, by plastically deforming a protruding end 32H that is a contact part of a side wall of a printed wiring board 10 and a side wall of an opening 30 of a metal frame 30G, the printed wiring board 10 and the metal frame 30G are joined. Therefore, since steps of filling and curing of an adhesive agent become unnecessary, production efficiency is enhanced and joining of the printed wiring boards 10 to the metal frame 30G at a low price becomes possible.

Description

The present invention relates to a composite wiring board in which a wiring board is fixed using a metal frame, and a method for manufacturing the composite wiring board.

When mounting electronic components on a wiring board, or other processing, etc., considering the work efficiency, it is generally not a single wiring board but a composite in which the same wiring board is housed in a single wiring board housing kit. The above processing and the like are performed collectively on the wiring board. Patent Document 1 discloses a multi-piece wiring board accommodation kit including a plurality of piece wiring boards and a frame having an accommodation hole for accommodating the piece wiring boards.

JP 2011-23657 A

However, in the multi-piece wiring board housing kit of Patent Document 1, an adhesive is injected and bonded between the piece wiring board and the housing hole of the frame at the connection location, and an adhesive that bonds different materials is used. This is necessary, and a process for filling and curing the adhesive is required separately, so that the production efficiency is deteriorated. Furthermore, since the wiring boards are individually fixed in the receiving holes, the positional deviation between the wiring boards is increased, and a decrease in yield in the subsequent process is expected.

An object of the present invention is to provide a composite wiring board with high production efficiency and a method for manufacturing the composite wiring board.

The method for manufacturing a composite wiring board of the present invention comprises preparing a wiring board,
Preparing a metal frame with an opening;
Disposing the wiring board in the opening of the metal frame;
The present invention is characterized in that it includes elastically deforming a contact portion between the side wall of the wiring board and the side wall of the opening of the metal frame to join the wiring board and the metal frame.

In the method of manufacturing a composite wiring board according to the present invention, the wiring board and the metal frame are joined by elastically deforming the contact portion between the side wall of the wiring board and the side wall of the opening of the metal frame. On the other hand, the process of filling and curing the adhesive is not required and the number of processing steps is reduced, so that the production efficiency is increased and the wiring board can be joined to the metal frame at a low cost. Moreover, the wiring board can be removed from the metal frame without cutting the joint portion by elastically deforming the joint portion so that the joint is released after the reflow process.

The top view of the printed wiring board for multi-piece taking. The perspective view of the printed wiring board cut out to the piece. The perspective view of the printed wiring board processed with a laser. The top view of the state by which the printed wiring board was joined to the metal frame. The top view which expanded a part of metal frame. The partial cross section figure of a composite wiring board. The top view of the printed wiring board removed from the composite wiring board. Sectional drawing of the printed wiring board of 1st Embodiment. Sectional drawing of the printed wiring board of 1st Embodiment with which the electronic component was mounted. The top view of the state by which the printed wiring board was joined to the metal frame of 2nd Embodiment.

[First embodiment]
In the composite wiring board 100 of the present embodiment, in order to prevent warping of the printed wiring board 10 during reflowing for mounting electronic components, a plurality of printed wiring boards 10 that perform reflowing are fixed using a metal frame. It is composed.

FIG. 8 is a cross-sectional view of the printed wiring board 10 according to the first embodiment before mounting electronic components.
In the printed wiring board 10, interlayer insulating layers 50A, 50C, 50E, 50G, and 50I are laminated on the upper surface (first surface) F side of the core insulating layer 50M disposed in the center, and the lower surface (second surface) S side. Interlayer insulating layers 50B, 50D, 50F, 50H, and 50J are laminated. The conductor circuit 58Ma on the first surface F and the conductor circuit 58Mb on the second surface S of the core insulating layer 50M are connected via a via conductor 60M. The core material is disposed in the core insulating layer 50M, and the core material is similarly disposed in the interlayer insulating layers 50A, 50C, 50E, 50G, and 50I and the interlayer insulating layers 50B, 50D, 50F, 50H, and 50J.

In the interlayer insulating layer 50A stacked on the first surface F side of the core insulating layer 50M, a via conductor 60A for connecting the conductor circuit 58A on the interlayer insulating layer 50A to the conductor circuit 58Ma of the core insulating layer 50M is provided. Is formed. Via conductor 60C for connecting conductor circuit 58C on interlayer insulating layer 50C to conductor circuit 58A on interlayer insulating layer 50A is formed in interlayer insulating layer 50C laminated on interlayer insulating layer 50A. Yes. Via conductor 60E for connecting conductor circuit 58E on interlayer insulating layer 50E to conductor circuit 58C on interlayer insulating layer 50C is formed in interlayer insulating layer 50E laminated on interlayer insulating layer 50C. Yes. A via conductor 60G for connecting the conductor circuit 58G on the interlayer insulating layer 50G to the conductor circuit 58E on the interlayer insulating layer 50E is formed in the interlayer insulating layer 50G laminated on the interlayer insulating layer 50E. Yes. Via conductor 60I for connecting conductor circuit 58I on interlayer insulating layer 50I to conductor circuit 58G on interlayer insulating layer 50G is formed in interlayer insulating layer 50I stacked on interlayer insulating layer 50G. Yes. A solder resist layer 62F is formed on the interlayer insulating layer 50I, and a conductor circuit 58I exposed from the opening 64F of the solder resist layer constitutes a pad 66F.

In the interlayer insulating layer 50B stacked on the second surface S side of the core insulating layer 50M, a via conductor 60B for connecting the conductor circuit 58B on the interlayer insulating layer 50B to the conductor circuit 58Mb of the core insulating layer 50M is provided. Is formed. A via conductor 60D for connecting the conductor circuit 58D on the interlayer insulation layer 50D to the conductor circuit 58B on the interlayer insulation layer 50B is formed on the interlayer insulation layer 50D laminated on the interlayer insulation layer 50B. Yes. Via conductor 60F for connecting conductor circuit 58F on interlayer insulating layer 50F to conductor circuit 58D on interlayer insulating layer 50D is formed in interlayer insulating layer 50F stacked on interlayer insulating layer 50D. Yes. Via conductor 60H for connecting conductor circuit 58H on interlayer insulating layer 50H to conductor circuit 58F on interlayer insulating layer 50F is formed in interlayer insulating layer 50H laminated on interlayer insulating layer 50F. Yes. Via conductor 60J for connecting conductor circuit 58J on interlayer insulating layer 50J to conductor circuit 58H on interlayer insulating layer 50H is formed in interlayer insulating layer 50J laminated on interlayer insulating layer 50H. Yes. A solder resist layer 62S is formed on the interlayer insulating layer 50J, and the conductor circuit 58J exposed from the opening 64S of the solder resist layer constitutes a pad 66S. Through holes 52 penetrating through the interlayer insulating layers 50I, 50G, 50E, 50C, 50A, 50M, 50B, 50D, 50F, 50H, and 50J are formed.

FIG. 9 is a cross-sectional view of the printed wiring board 10 on which the electronic component 11 is mounted.
The electronic component 11 is mounted on the first surface F side of the printed wiring board 10 via solder 68 provided on the pad 66F. The electronic component 11 is mounted on the second surface S side of the printed wiring board 10 via the solder 68 provided on the pad 66S.

FIG. 1 is a plan view of a multi-piece printed wiring board 10G in which 8 × 4 printed wiring boards 10 are manufactured, and FIG. 2 is a perspective view of the printed wiring board 10 cut into individual pieces. FIG. 8 shows a part of the X1-X1 cross section in FIG.
As shown in FIG. 1, a plurality of printed wiring boards 10 are manufactured inside a frame portion 18 on the outer periphery of the multi-piece printed wiring board 10G. As shown in FIG. 2, the printed wiring board 10 is formed with a rectangular main body 20 having a longitudinal side wall 14V and a short side wall 14H, and the short side wall 14H has a substantially semicircular shape. Two support pieces 12H are formed so as to face each other with the main body 20 interposed therebetween.

In the first embodiment, when the printed wiring board 10 is cut out from the multiple printed wiring board 10G, as shown in FIG. 3A, the printed wiring board 10 is cut with a laser along the outer shape of the printed wiring board 10, Cut into individual pieces as shown in FIG.

4A is a plan view showing a state before some of the printed wiring boards 10 are supported by the metal frame 30G. FIG. 4B is a plan view of the printed wiring boards 10 supported by the metal frame 30G. It is a top view which shows the state made. FIG. 5 is an enlarged plan view showing a part of the metal frame 30G.
In this embodiment, the composite wiring board 100 includes an aluminum metal frame 30 </ b> G for joining the four printed wiring boards 10. As shown in FIG. 4A, the metal frame 30G is provided with four accommodating openings 30 for accommodating the printed wiring board 10, and positioning holes 38 are formed at the four corners. A vertical wall 34V corresponding to the longitudinal side wall 14V of the printed wiring board 10 and a horizontal wall 34H corresponding to the short side wall 14H of the printed wiring board 10 are formed in the opening 30 for accommodation. Four protruding ends 32H corresponding to the support pieces 12H of the wiring board 10 are formed.

As shown in FIG. 5, the projecting end 32H is formed so that its inner edge 32a is slightly smaller than the outer edge of the support piece 12H and becomes thinner toward the tip end side so as to be elastically deformable. In particular, the inner edge 32a is formed such that the gap becomes narrower toward the tip side. Each protrusion 32H is formed such that a predetermined clearance is interposed between the longitudinal side wall 14V and the vertical wall 34V of the printed wiring board 10 joined by the support piece 12H.

As shown in FIG. 4 (B), each supporting piece 12H is pressed against the corresponding protruding end 32H from above and joined to the inner edge 32a of the protruding end 32H so as to sandwich the supporting piece 12H. The plate 10 is housed and fixed in the housing opening 30. Thereby, the composite wiring board 100 for reflow formed by joining each printed wiring board 10 to the metal frame 30G is completed.

In the composite wiring board 100 of the first embodiment, the printed wiring board 10 and the metal frame 30G are elastically deformed at the protruding end 32H that is a contact portion between the side wall of the printed wiring board 10 and the side wall of the opening 30 of the metal frame 30G. Since bonding is performed, an adhesive filling / curing step is not required for the bonding method using an adhesive, and the number of processing steps is reduced. Therefore, the production efficiency is increased, and the printed wiring board 10 is reduced to the metal frame 30G. Can be joined. In addition, you may use an adhesive agent together in a joining location. In this case, the joint strength between the printed wiring board 10 and the metal frame 30G can be further improved by using the adhesive together.

FIG. 6A shows a part of the X2-X2 cross section of the printed wiring board 10 of FIG.
The metal frame 30G has a thickness t1: 750 μm. The printed wiring board 10 has a thickness t2 of 780 μm. That is, the thickness of the metal frame 30G is thinner than that of the printed wiring board 10. Further, as shown in FIG. 6A, the printed wiring board 10 is joined to the metal frame 30G so that the center plane C2 in the thickness direction coincides with the center plane C1 in the thickness direction of the metal frame 30G. . For this reason, the metal frame 30G is recessed from the first surface F of the printed wiring board 10, and the metal frame 30G is recessed from the second surface S of the printed wiring board 10. Thereby, the metal frame 30G does not interfere when the electronic components of the printed wiring board 10 are mounted.

The thermal expansion coefficient in the main surface direction of the aluminum metal frame 30G is 23 ppm / ° C., the thermal expansion coefficient in the main surface direction of the resin printed wiring board 10 is 16 ppm / ° C., and the thermal expansion coefficient of the metal frame 30G is printed. It is larger than the thermal expansion coefficient of the wiring board 10. By adjusting the thickness of the metal frame 30G to be thinner than that of the printed wiring board 10, it is adjusted so as to suppress the warpage of the printed wiring board 10 due to the difference in thermal expansion coefficient. In the first embodiment, aluminum is used as the material of the metal frame 30G. However, copper, stainless steel, or the like can be used as long as it has a coefficient of thermal expansion greater than that of the printed wiring board 10.

Solder printing is performed in a state where each printed wiring board 10 is bonded to the metal frame 30G by elastic deformation of each protrusion 32H, and the electronic component 11 and the like are placed, and the electronic component 11 and the like are mounted in a reflow furnace. Is called. Since the reflow temperature near 200 ° C. exceeds the Tg (glass transition point) of the resin constituting the printed wiring board 10, the printed wiring board 10 is warped due to the weight of the electronic component 11 to be mounted and the residual stress of the board. easy. Here, in the first embodiment, as shown in FIG. 6B, the printed wiring board 10 bonded to the metal frame 30G moves toward the center side along with the stress due to the weight of the electronic component 11 or the like. However, since the thermal expansion coefficient in the main surface direction of the metal frame 30G is larger than the thermal expansion coefficient of the printed wiring board 10 as described above, the metal frame 30G is relatively more than the printed wiring board 10. It spreads in the surface direction. For this reason, the stress F1 to the outer edge side which cancels the stress to the center side mentioned above acts on the printed wiring board 10 via each support piece 12H. Thereby, the printed wiring board 10 is not warped even in reflow.

FIG. 7 is a plan view showing a state in which the printed wiring board 10 is removed from the composite wiring board 100.
After mounting the electronic components, as shown in FIG. 7, each protruding end 32H is elastically deformed and each printed wiring board 10 is removed from the metal frame 30G. Thereby, the printed wiring board 10 can be removed from the metal frame 30G without cutting the joint portion.

The printed wiring board 10 of the first modified example of the first embodiment is configured as shown in FIG. 8, and a core material is disposed in the core insulating layer 50M, and the interlayer insulating layers 50A, 50C, 50E, 50G, and 50I, and interlayer insulation No core material is disposed on the layers 50B, 50D, 50F, 50H, and 50J. For this reason, although the printed wiring board 10 is likely to be warped, the metal wiring 30G does not warp the printed wiring board 10 even during reflow.

[Second Embodiment]
FIG. 10 is an enlarged plan view showing a state in which the printed wiring board 10a is joined to the metal frame 30Ga of the second embodiment.
As shown in FIG. 10, the composite wiring board 100a according to the second embodiment is provided with a protrusion 16H corresponding to the protrusion 32H described above on the short side wall 14H of the printed wiring board 10a so as to be elastically deformable. A support piece 36H for joining the protruding end 16H is provided on the lateral wall 34H of the opening 30 of the metal frame 30Ga.

Then, the protrusion 16H and the support piece 36H are joined using the elastic force of the protrusion 16H elastically deformed by pressing the protrusion 16H of the printed wiring board 10a against the support piece 36H of the corresponding metal frame 30Ga. Thereby, each printed wiring board 10a is accommodated in the accommodation opening 30 and fixed. Even if the printed wiring board 10a and the metal frame 30Ga are joined in this manner, the filling / curing process of the adhesive is not required and the processing process is reduced as compared with the joining method using the adhesive. Efficiency increases and the printed wiring board 10a can be joined to the metal frame 30Ga at a low cost.

The present invention is not limited to the above-described embodiments. For example, the present invention may be embodied as follows, and other detailed configurations may be appropriately changed within the scope of the gist of the present invention. Is possible.
(1) In each of the above embodiments, the metal frame 30G is not limited to the four openings 30, and a plurality of openings 30 can be formed according to the number of printed wiring boards 10 to be joined. .

(2) In the first embodiment, with respect to the composite wiring board 100 after mounting electronic components, the rectangular main body 20 is cut off from the support piece 12H of the printed wiring board 10, and the support piece 12H is formed on the protruding end 32H of the metal frame 30G. The main body 20 may be separated from each other in a state in which Further, in the second embodiment, with respect to the composite wiring board 100 after mounting the electronic components, the rectangular main body 20 is cut off from the protruding end of the printed wiring board 10, leaving the protruding end on the side wall of the opening 30 of the metal frame 30G. In the state, the main body portions 20 may be separated from each other.

(3) In each of the above-described embodiments, each printed wiring board 10 is not limited to being sandwiched between the protruding end 32H where the support piece 12H is elastically deformed and joined to the metal frame 30G, but the side wall and the opening 30 of the metal frame 30G. It may be joined to the metal frame 30G in a state where the contact portion with the side wall is elastically deformed.

(4) In each of the above embodiments, the frame portion made of the metal frame 30G preferably has higher rigidity than the piece portion made of the printed wiring board 10 at the solder reflow temperature.

10 Printed Wiring Board 12H Supporting Piece 30G Metal Frame 30 Opening 32H Protrusion 100 Composite Wiring Board

Claims (12)

Preparing a wiring board;
Preparing a metal frame with an opening;
Disposing the wiring board in the opening of the metal frame;
A method of manufacturing a composite wiring board, comprising: elastically deforming a contact portion between the side wall of the wiring board and the side wall of the opening of the metal frame to join the wiring board and the metal frame. It is a manufacturing method of the composite wiring board according to claim 1,
The metal frame is elastically deformed to join the wiring board and the metal frame. It is a manufacturing method of the composite wiring board according to claim 2,
The protrusion formed on the side wall of the opening is elastically deformed to join the protrusion to the side wall of the wiring board. It is a manufacturing method of the composite wiring board according to claim 1,
The protruding end formed on the side wall of the wiring board is elastically deformed to join the protruding end and the side wall of the opening. A method of manufacturing a composite wiring board according to any one of claims 1 to 4,
The wiring board is arranged such that the surface of the metal frame does not protrude from the surface of the wiring board and the back surface of the metal frame does not protrude from the back surface of the wiring board. A method for producing a composite wiring board according to claim 5,
The wiring board is arranged so that a center line in the thickness direction of the wiring board and a center line in the thickness direction of the metal frame coincide with each other. A wiring board;
A metal frame having an opening for accommodating the wiring board;
By elastic deformation of the contact portion between the side wall of the wiring board and the side wall of the opening of the metal frame, the side wall of the wiring board and the side wall of the opening of the metal frame are joined, and the wiring board is fixed to the metal frame. Composite wiring board. The composite wiring board according to claim 7,
The wiring board and the metal frame are joined by elastic deformation of the metal frame. The composite wiring board according to claim 8, wherein
The protruding end and the side wall of the wiring board are joined by elastic deformation of the protruding end formed on the side wall of the opening. The composite wiring board according to claim 7,
The protruding end and the side wall of the opening are joined by elastic deformation of the protruding end formed on the side wall of the wiring board. It is a composite wiring board as described in any one of Claims 7-10,
The surface of the metal frame does not protrude from the surface of the wiring board, and the back surface of the metal frame does not protrude from the back surface of the wiring board. The composite wiring board according to claim 11,
A center line in the thickness direction of the metal frame coincides with a center line in the thickness direction of the wiring board.

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