JP2015170634A - 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 same.SOLUTION: With deformed metal frames 30Ga, 30Gb, portions on main surface sides (a first surface F side and a second surface S side) of each of side end parts 12V, 12H of a printed wiring board 10 and recesses 32V, 32H 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 board 10 to the metal frames 30Ga, 30Gb 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.

The objective of this invention is providing the manufacturing method of a composite wiring board and composite wiring board with high production efficiency.

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 deforming the metal frame and joining a portion on the main surface side of the wiring board and a part of the metal frame.

In the method for manufacturing a composite wiring board according to the present invention, the portion on the main surface side of the wiring board and a part of the metal frame are joined by the deformed metal frame. This eliminates the need for an adhesive filling / curing step and reduces the number of processing steps as compared with a bonding method using an adhesive, thereby increasing the production efficiency and allowing the wiring board to be bonded to the metal frame at a low cost. Since the portion on the main surface side of the wiring board serves as a bonding surface, the bonding area can be easily increased as compared with the case where bonding is performed on the side wall of the wiring board, so that the bonding strength can be easily improved.

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 clamped between both metal frames. It is a top view which shows opening of the lower metal frame in which the printed wiring board was mounted. The expanded sectional view which shows the state which pinched | interposed the printed wiring board with both metal frames. The top view of the printed wiring board by which the crimping process was carried out. Sectional drawing of the crimping processing machine of 1st Embodiment. Partial cross section of 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. Sectional drawing of the composite wiring board which concerns on the 2nd modification of 1st 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. 11 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. 12 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. 11 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 so that two side end portions 12V are opposed to the longitudinal side wall 14V of one side of the rectangular main body portion 20 with the main body portion 20 interposed therebetween. . Two side end portions 12H are formed on one side in the lateral direction side wall 14H so as to face each other with the main body portion 20 interposed therebetween. The side end 12V and the side end 12H have the same shape and are formed so that the thickness thereof is thinner than that of the main body 20, and a rectangular base (bridge) 12b and a trapezoid 12a having a width that expands toward the tip. It consists of.

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 in which the printed wiring board 10 is placed on the lower metal frame 30Ga, and FIG. 4B shows the printed wiring board 10 sandwiched between both metal frames 30Ga and 30Gb. It is a top view which shows a state. FIG. 5 is a plan view showing the opening 30 of the lower metal frame 30Ga on which the printed wiring board 10 is placed. FIG. 6 is a cross-sectional view showing a part of the X2-X2 cross section of the printed wiring board 10 of FIG.
In the present embodiment, the composite wiring board 100 includes two metal frames for joining the four printed wiring boards 10 as shown in FIGS. Both metal frames are aluminum frames, and are composed of a lower metal frame 30Ga that supports each printed wiring board 10 from below and an upper metal frame 30Gb that supports each printed wiring board 10 from above.

The lower metal frame 30Ga includes four accommodating openings 30 for accommodating the printed wiring board 10, and positioning holes 38 are formed at the four corners. As shown in FIG. 5, a vertical wall 34 </ b> V corresponding to the longitudinal side wall 14 </ b> V of the printed wiring board 10 and a lateral wall 34 </ b> H corresponding to the short side wall 14 </ b> H of the printed wiring board 10 are formed in the housing opening 30. Has been. Four concave portions 32V corresponding to the four side end portions 12V of the printed wiring board are formed on the vertical wall 34V, and four concave portions corresponding to the four side end portions 12H of the printed wiring board are formed on the horizontal wall 34H. 32H is formed. The upper metal frame 30Gb is formed to have a target shape with the lower metal frame 30Ga via the printed wiring board 10. The concave portions 32H and 32V have the same shape and a base portion 32b corresponding to the rectangular base portion (bridge portion) 12b at the side end portion of the printed wiring board, and a trapezoid portion 32a corresponding to the trapezoid portion 12a at the side end portion of the printed wiring board. Consists of. The trapezoidal portion 32 a has a width that increases toward the outer edge of the opening 30 for accommodation.

As shown in FIG. 6, the concave portions 32V of both metal frames 30Ga and 30Gb constitute a sandwiching portion that sandwiches the side end portion 12V. Further, the concave portions 32H of both the metal frames 30Ga and 30Gb also constitute a holding portion that holds the side end portion 12H. The depth of the recess 32V and the recess 32H is such that when the lower metal frame 30Ga and the upper metal frame 30Gb are bonded together via the printed wiring board 10, the central plane C2 in the thickness direction of the printed wiring board 10 sandwiched between them. It is set to coincide with the center plane C1 in the thickness direction of the bonded metal frame. The lower metal frame 30Ga and the upper metal frame 30Gb are formed such that the thickness t1 (for example, 750 μm) of the two metal frames 30Ga and 30Gb bonded is thinner than the thickness t2 (for example, 780 μm) of the printed wiring board 10. ing. For this reason, the upper metal frame 30Gb is recessed from the first surface F of the printed wiring board 10, and the lower metal frame 30Ga is recessed from the second surface S of the printed wiring board 10. Thereby, when mounting the electronic component of the printed wiring board 10, both metal frames 30Ga and 30Gb do not interfere.

The thermal expansion coefficient in the main surface direction of both aluminum metal frames 30Ga and 30Gb is 23 ppm / ° C., and the thermal expansion coefficient in the main surface direction of the resin printed wiring board 10 is 16 ppm / ° C., both metal frames 30Ga and 30Gb. Is larger than the thermal expansion coefficient of the printed wiring board 10. By adjusting the thickness t1 of the bonded metal frames 30Ga and 30Gb to be smaller than the thickness t2 of the printed wiring board 10, adjustment is made 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 both the metal frames 30Ga and 30Gb, but copper, stainless steel, etc. can be used as long as it has a coefficient of thermal expansion greater than that of the printed wiring board 10.

FIG. 7 shows a state in which the printed wiring board 10 is bonded to both the metal frames 30Ga and 30Gb by caulking.
As shown in FIG. 7, crimping portions 36 are respectively formed on the recesses 32 </ b> V and the recesses 32 </ b> H sandwiching the side ends 12 </ b> V and 12 </ b> H of the printed wiring board 10 using a crimping machine 200. By this crimping portion 36, the bottom walls of the recesses 32V and 32H of the lower metal frame 30Ga are plastically deformed and joined so as to abut against the second surface S side of the side end portion 12V, and the recess 32V of the upper metal frame 30Gb is joined. , 32H are plastically deformed and joined so that the bottom wall of the side end portion 12V faces the first surface F side. Further, crimping portions 36a for joining the lower metal frame 30Ga and the upper metal frame 30Gb simultaneously with the joining to the recesses 32V and 32H are formed, for example, at the positions illustrated in FIG. The In addition, the crimping process part 36a is not restricted to being formed simultaneously with the crimping process part 36, For example, you may form in the crimping process before and after the crimping process which forms the crimping process part 36.

FIG. 8A is a cross-sectional view of a caulking machine 200 that performs caulking on both metal frames 30Ga and 30Gb.
The caulking machine 200 is a machine that performs caulking on both metal frames 30Ga and 30Gb in which the side end portions 12V and 12H of each printed wiring board 10 are supported by the recesses 32V and 32H. An upper mold 220 is provided. The lower mold 210 includes a base portion 211 and a support plate 212. The support plate 212 is supported so as to be vertically movable with respect to the base portion 211. The base portion 211 is provided with a punch 213 that performs caulking, and the support plate 212 is formed with a through hole 212a through which the punch 213 is passed. A concave portion 212b is formed in the central portion of the support plate 212 so that no force is applied to the main body portion 20 of the printed wiring board 10 during caulking. The main body portion 20 of the printed wiring board 10 is placed on the recess 212b, and both metal frames 30Ga and 30Gb are placed on the support plate 212.

The upper mold 220 includes a base portion 221 and a support plate 222. The support plate 222 is supported so as to be vertically movable with respect to the base portion 221. The base portion 221 is provided with a punch 223 that performs caulking, and the support plate 222 is formed with a through-hole 222a through which the punch 223 is passed. A concave portion 222b is formed in the central portion of the support plate 222 so that no force is applied to the main body portion 20 of the printed wiring board 10 during caulking.

8B, the upper mold 220 is pressed against the lower mold 210, the punch 223 of the upper mold 220 is pressed against the bottom walls of the recesses 32V and 32H of the upper metal frame 30Gb, and the recess 32V of the lower metal frame 30Ga. , 32H, the punch 213 of the lower mold 210 is pressed against the bottom wall.
With respect to both the metal frames 30Ga and 30Gb in the state shown in FIG. 4B, the crimping machines 36 shown in FIG. 7 and the crimping parts for joining the metal frames 30Ga and 30Gb shown in FIG. It is formed. Each printed wiring board 10 is joined to both metal frames 30Ga and 30Gb by each side edge 12V and 12H being sandwiched by the corresponding recesses 32V and 32H by the crimping portions 36 formed in this way. The reflow composite wiring board 100 is completed.

In the composite wiring board 100 of the first embodiment, the portions on the main surface side (the first surface F side and the second surface S side) of the side end portions 12V and 12H of the printed wiring board 10 by the deformed metal frames 30Ga and 30Gb. And the recesses 32V and 32H are joined. This eliminates the need for an adhesive filling / curing step and reduces the number of processing steps compared to a bonding method using an adhesive, thereby increasing the production efficiency and reducing the cost of the printed wiring board 10 to the metal frames 30Ga and 30Gb. Can be joined. Since the portion on the main surface side of the printed wiring board 10 becomes a bonding surface, it is easy to increase the bonding area as compared with the case of bonding at the side wall of the printed wiring board 10, so that the bonding strength can be easily improved. it can. 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 frames 30Ga and 30Gb can be further improved by using the adhesive together.

In addition, since the crimped portion 36 is simultaneously formed in the concave portions 32V and 32H of both the metal frames 30Ga and 30Gb, the printed wiring board 10 can be accurately positioned with respect to both the metal frames 30Ga and 30Gb. Further, the positional deviation between the printed wiring boards can be reduced.

With the printed wiring board 10 joined to both the metal frames 30Ga and 30Gb by caulking (see FIG. 7), solder printing is performed, the electronic component 11 and the like are placed, and the electronic component 11 and the like are placed in a reflow furnace. Implementation is done. 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, the printed wiring board 10 bonded to each of the metal frames 30Ga and 30Gb is moved toward the center of the printed wiring board 10 together with the stress due to the weight of the electronic component 11 and the like as shown in FIG. However, since the thermal expansion coefficient in the main surface direction of each metal frame 30Ga, 30Gb is larger than the thermal expansion coefficient of the printed wiring board 10 as described above, The metal frames 30Ga and 30Gb spread 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 side edge part 12V and 12H. Thereby, the printed wiring board 10 is not warped even in reflow.

FIG. 10 is a plan view showing a state in which the printed wiring board 10 is cut out from the composite wiring board 100.
After mounting the electronic components, as shown in FIG. 10, the rectangular main body 20 was cut off from the side ends 12V and 12H of the printed wiring board 10 and sandwiched between the recesses 32V and 32H of both metal frames 30Ga and 30Gb. The main body 20 of the printed wiring board 10 is separated while leaving the side end portions 12V and 12H.

[First Modification of First Embodiment]
The printed wiring board 10 of the first modified example of the first embodiment is configured as shown in FIG. 11, the core material is disposed in the core insulating layer 50M, the interlayer insulating layers 50A, 50C, 50E, 50G, 50I, the 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 warp, both the metal frames 30Ga and 30Gb do not cause the printed wiring board 10 to warp even during reflow.

[Second modification of the first embodiment]
FIG. 13 is a cross-sectional view showing the main parts of a composite wiring board according to a second modification of the first embodiment.
In the second modified example of the first embodiment, as shown in FIG. 13, the slit 33 corresponding to the side end portions 12V and 12H having the same thickness as the side end portions 12V and 12H of the printed wiring board 10 is formed. The metal frame 30Gc to be formed and two metal frames 30Gd and 30Ge in which only the opening 30 in which the recesses 32V and 32H are not formed are provided. The side end portions 12V and 12H are sandwiched by a sandwiching portion configured by bonding three metal frames 30Gc to 30Ge. Even in this case, the crimping portion is formed with respect to the metal frame 30Gd and 30Ge forming the clamping portion, so that it is clamped with the main surface side portions of the side end portions 12V and 12H of the printed wiring board 10. Can be fixed to the metal frames 30Gc to 30Ge to which the printed wiring boards 10 are bonded. Moreover, the crimping process part which joins each metal frame 30Gc-30Ge simultaneously with the crimping process part with respect to each clamping part can be formed.

The present invention is not limited to the above-described embodiment. 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. It is.
(1) When the side end portions 12V and 12H are sandwiched without being displaced by the sandwiching portion formed of the metal frames 30Ga and 30Gb and the metal frames 30Gc to 30Ge, the caulking process is performed on the recesses 32V and 32H. May be eliminated.

(2) The printed wiring board 10 and the printed wiring board 10 are formed by plastic processing different from the caulking processing on the holding portions formed by the metal frames 30Ga and 30Gb and the metal frames 30Gc to 30Ge holding the side ends 12V and 12H of the printed wiring board 10. The metal frame may be joined, or for example, the printed wiring board 10 and the metal frame may be joined by elastically deforming the sandwiching portion.

(3) In the above embodiment, the metal frames 30Ga and 30Gb and the metal frames 30Gc to 30Ge are not limited to the four openings 30, and a plurality of openings depending on the number of printed wiring boards 10 to be joined. 30 can be formed.

(4) In the above embodiment, it is preferable that the frame portion made of the metal frames 30Ga and 30Gb and the metal frames 30Gc to 30Ge has higher rigidity than the piece portion made of the printed wiring board 10 at the solder reflow temperature.

DESCRIPTION OF SYMBOLS 10 Printed wiring board 12V, 12H Side edge part 30Ga-30Ge Metal frame 30 Opening 32V, 32H Concave 100 Composite wiring board

Claims (10)

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: deforming the metal frame, and joining a portion on a main surface side of the wiring board and a part of the metal frame. It is a manufacturing method of the composite wiring board according to claim 1,
In the joining, the side end portion formed on the side wall of the wiring board is sandwiched and joined by the sandwiching portion formed on the metal frame. It is a manufacturing method of the composite wiring board according to claim 2,
In the joining, the sandwiching portion is deformed to join the main surface side portion of the side end portion and a part of the metal frame. It is a manufacturing method of the composite wiring board according to claim 3,
In the preparation, a plurality of the metal frames are prepared,
In the joining, the clamping part formed by the plurality of metal frames is deformed to join the main surface side portion of the side end part and a part of the metal frame,
Further, in the joining, the plurality of metal frames are joined together. A method of manufacturing a composite wiring board according to any one of claims 1 to 4,
In the joining, the metal frame is plastically deformed, and the portion on the main surface side of the wiring board and a part of the metal frame are joined. A wiring board;
A metal frame having an opening for accommodating the wiring board;
A composite wiring board in which a portion on the main surface side of the wiring board and a part of the metal frame are joined by deforming the metal frame, and the wiring board is fixed to the metal frame. The composite wiring board according to claim 6,
The metal frame includes a clamping portion that clamps a side end portion formed on a side wall of the wiring board. The composite wiring board according to claim 7,
By deforming the clamping part, the part on the main surface side of the side end part and a part of the metal frame are joined. The composite wiring board according to claim 8, wherein
The clamping part is formed by a plurality of metal frames,
By deforming the clamping part, the main surface side portion of the side end part and a part of the metal frame are joined, and the plurality of metal frames are joined together. A composite wiring board according to any one of claims 6 to 9,
By plastically deforming the metal frame, a portion on the main surface side of the wiring board and a part of the metal frame are joined.

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