JP5807671B2 - Wiring board and method of manufacturing wiring board - Google Patents

Description

The present invention relates to a wiring board in which a first metal plate and a second metal plate provided on an insulating substrate are conductive at an interlayer connection portion, and a method for manufacturing the wiring board.

As a wiring board in which metal plates are provided on both surfaces of an insulating substrate and the respective metal plates are interlayer-connected, for example, a substrate described in Patent Document 1 is known.
As shown in FIG. 9, the substrate 100 described in Patent Document 1 is provided with metal plates 102 and 103 on both surfaces of a ceramic plate 101. A through hole 104 is formed in the ceramic plate 101. The metal plate 102 is also provided with a through hole 105 facing the through hole 104 of the ceramic plate 101. The peripheral edge of the through hole 105 provided in the metal plate 102 is bent toward the through hole 104 of the ceramic plate 101. The substrate 100 is connected to both metal plates 102 and 103 by solder filled in the through holes 104 and 105. In the substrate 100 of Patent Document 1, after the metal plates 102 and 103 are joined to the ceramic plate 101 in which the through hole 104 is formed, the through hole 105 is formed in the metal plate 102 by etching, and then the diameter of the through hole 105 is larger. By inserting the columnar member 106 into the through hole 105, the periphery of the through hole 105 is bent. Bending the periphery of the through hole 105 facilitates positioning of the solder.

JP 2001-284800 A

  By the way, as in Patent Document 1, when the metal plate 102 is processed, a force directed toward the ceramic plate 101 acts on the periphery of the through hole 105 by the columnar member 106. On the other hand, in the metal plate 102, as the distance from the place pressed by the cylindrical member 106 increases, a force in a direction away from the ceramic plate 101 acts, and this force may cause the metal plate 102 to peel from the ceramic plate 101. .

The present invention has been made in view of such problems of the prior art, and an object of the present invention is to provide a wiring board in which a metal plate is difficult to peel from an insulating substrate and a method for manufacturing the wiring board.

A method of manufacturing a wiring board that solves the above problems includes a first metal plate provided on the surface of an insulating substrate, and a second metal plate provided on the back surface of the insulating substrate and having a protrusion. And the manufacturing method of the wiring board which made the said 1st metal plate and the said convex part oppose, Comprising: The 1st process of forming a several metal plate through-hole in the said 2nd metal plate, a second metal plate, by forming a single protrusion with respect to said plurality of metal plates through holes, Ru is inclined in the axial direction of the plurality of metal plates through holes with respect to the axial direction of the convex portion Including a second step and a third step of providing the insulating substrate with the first metal plate and the second metal plate so that the convex portion faces the insulating substrate. To do.

  According to this, after forming the metal plate through hole and the convex portion in the second metal plate, that is, after processing the second metal plate, the first metal plate and the second metal plate are formed on the insulating substrate. Provided. By providing the insulating plate after processing the metal plate, there is no need to process the metal plate provided on the insulating substrate, and the metal plate does not peel from the insulating substrate along with the processing of the metal plate.

  About the manufacturing method of the said wiring board, it fills with a electrically conductive material between the said convex part and a said 1st metal plate, and forms the 4th layer connection part of a said 1st metal plate and a said 2nd metal plate. It is preferable to include these processes.

According to this, since the interlayer connection portion is formed in a state where the first metal plate and the second metal plate are provided on the insulating substrate, it is easy to form the interlayer connection portion.
About the manufacturing method of the said wiring board, in the said 1st process, it is preferable that these metal plate through-holes are formed in the position used as the base end of the said convex part.

According to this, when forming a convex part, since the rigidity of a 2nd metal plate is falling with the metal plate through-hole, it is easy to form a convex part.
Regarding the method for manufacturing the wiring board, in the first step, the metal plate through hole is preferably formed by pressing.

According to this, a metal plate through-hole can be formed easily.
About the manufacturing method of the said wiring board, it is preferable that the said metal plate through-hole is a through-hole for a test | inspection or a degassing through-hole which confirms the filling state of a electrically conductive material.

According to this, it can be confirmed whether or not the conductive material is sufficiently filled. Further, the gas generated when forming the interlayer connection portion can be discharged.
About the manufacturing method of the said wiring board, it is preferable that the said convex part which forms the said interlayer connection part is formed in multiple numbers, and the said convex part is formed also in the area | region different from the edge part of a said 2nd metal plate.

According to this, since a plurality of interlayer connection portions are formed, the first metal plate or the second metal plate is hardly peeled off from the insulating substrate.
Moreover, the wiring board which solves the said subject has the 1st metal plate provided in the surface of the insulated substrate, and the 2nd metal plate in which the convex part was formed while being provided in the back surface of the said insulated substrate. A wiring board in which the first metal plate and the convex portion are opposed to each other, and a plurality of metal plate through-holes are formed in the second metal plate, and the plurality of metal plate through-holes are formed. On the other hand, one convex portion is formed, the axial direction of the plurality of metal plate through holes is inclined with respect to the axial direction of the convex portion, and the convex portion is opposed to the insulating substrate. The gist is that the first metal plate and the second metal plate are provided on the insulating substrate.

  According to the present invention, the metal plate is difficult to peel from the insulating substrate.

(A) The top view by the side of the 1st metal plate which shows a part of wiring board in a 1st embodiment fractured | ruptured, (b) shows sectional drawing of the wiring board in 1st Embodiment (a). FIG. 2B is a cross-sectional view taken along line 1b-1b, and FIG. 4C is a plan view on the second metal plate side, showing a part of the wiring board according to the first embodiment. (A) is a top view of the 2nd metal plate in 1st Embodiment, (b) is an enlarged view which expands and shows a convex part and the through-hole for a test | inspection. (A) is a perspective view of the metal mold | die for holes in 1st Embodiment, (b) is a perspective view of the metal mold | die for convexes in 1st Embodiment. (A)-(d) is a schematic diagram which shows the process of forming the through-hole for an inspection and a convex part in the 2nd metal plate in 1st Embodiment. (A) And (b) is a schematic diagram which shows the process of forming a bending part in the 1st metal plate in 1st Embodiment. The schematic diagram for demonstrating the manufacturing process of the wiring board in 1st Embodiment. The schematic diagram for demonstrating the manufacturing process of the wiring board in 1st Embodiment. Sectional drawing which shows the wiring board in 2nd Embodiment. Sectional drawing of the board | substrate which shows a prior art.

(First embodiment)
Hereinafter, a first embodiment of the wiring board will be described.
As shown to Fig.1 (a)-(c), the wiring board 10 is comprised using the thick copper substrate. The wiring board 10 has a first metal plate 21 (copper plate) on the front surface 11 a of the insulating substrate 11 and a second metal plate 31 (copper plate) on the back surface 11 b of the insulating substrate 11. As the insulating substrate 11, for example, a glass epoxy resin substrate is used. The first metal plate 21 and the second metal plate 31 are bonded to the insulating substrate 11 with an adhesive. The first metal plate 21 and the second metal plate 31 are patterned into a desired shape to form a current path.

  The first metal plate 21 and the second metal plate 31 are connected by an interlayer connection portion 41. The insulating substrate 11 is provided with a base material through hole 13 penetrating in the thickness direction. The first metal plate 21 is provided with a through hole 22 that faces the base material through hole 13 and penetrates in the thickness direction. The diameter of the through hole 22 is smaller than the diameter of the substrate through hole 13. The peripheral edge of the through hole 22 is bent toward the base material through hole 13, thereby bending the front substrate 11 from the front surface 11 a side to the back surface 11 b side (second metal plate 31 side). Part 23 is configured.

  The second metal plate 31 is provided with a convex portion 32 that protrudes from the back surface 11b side of the insulating substrate 11 to the front surface 11a side (first metal plate 21 side). The convex part 32 has the circular bottom part 32a and the cylindrical cylinder part 32b provided in the periphery of the bottom part 32a. The convex portion 32 is provided with its outer peripheral surface facing the inner surface of the base material through hole 13 in the insulating substrate 11. The convex portion 32 is inserted into the base material through hole 13 and the through hole 22. Thereby, the convex portion 32 faces the inner peripheral surface of the through hole 22 in the first metal plate 21. The convex portion 32 covers the inner surface of the base material through hole 13 together with the bent portion 23.

  The second metal plate 31 is provided with a circular inspection through hole 33 as a metal plate through hole penetrating in the thickness direction so as to face the substrate through hole 13. The inspection through hole 33 is provided in a state where the axial direction of the inspection through hole 33 is inclined with respect to the axial direction of the convex portion 32. The inspection through hole 33 communicates with the base material through hole 13. The inspection through holes 33 are provided at four locations and are provided so as to surround the convex portion 32. The inspection through-hole 33 is provided at a position that becomes the base end of the convex portion 32 (periphery of the convex portion 32).

  The bent part 23 and the convex part 32 are connected by an interlayer connection part 41. The interlayer connection portion 41 is solder filled in each of the through hole 22, the base material through hole 13, and the inspection through hole 33. Solder is also filled between the bent portion 23 and the convex portion 32, and the bent portion 23 and the convex portion 32 are connected by the interlayer connection portion 41.

  In FIG. 1, for convenience of explanation, only one interlayer connection portion 41 provided on the wiring board 10 is illustrated and described. However, the wiring board 10 is different from the end in addition to the end of the wiring board 10. An interlayer connection portion 41 is also provided in the region.

Next, the manufacturing method of the wiring board 10 of this embodiment is demonstrated.
First, as shown in FIGS. 2A and 2B, a plurality of inspection through holes 33 are formed in the second metal plate 31. The inspection through-hole 33 of the second metal plate 31 is pressed by a mold.

  As shown in FIGS. 3A and 4A, a hole mold 50 for pressing the inspection through hole 33 in the second metal plate 31 includes a hole forming mold 51, a support mold, and the like. And a mold 55. The hole forming mold 51 has a columnar hole forming protrusion 53 on one surface of a columnar support portion 52. The number of hole forming projections 53 can be arbitrarily set, and is set in accordance with the number of inspection through holes 33 formed in the second metal plate 31. In this embodiment, four sets of hole forming projections 53 corresponding to each interlayer connection portion 41 are provided as a set, and four sets of hole forming projections 53 are provided. The support die 55 has four recesses 54 corresponding to regions surrounding the pair of hole forming projections 53.

  Then, as shown in FIGS. 4A and 4B, the second metal plate 31 is placed on the support mold 55. Next, when the second metal plate 31 is pressed by the hole forming die 51, the second metal plate 31 is punched by the hole forming protrusions 53, and the inspection through hole 33 is formed at the punched position. (First step).

Next, the convex portion 32 is formed on the second metal plate 31. The convex portion 32 of the second metal plate 31 is pressed by a mold.
As shown in FIGS. 3B and 4B, the convex mold 60 for pressing the convex portion 32 on the second metal plate 31 includes a convex mold 61, a support mold 65, and the like. have. The convex mold 61 has a cylindrical convex projection 63 on one surface of a columnar support 62. One protrusion 63 is provided corresponding to each interlayer connection 41. The diameter of the protrusion 63 for protrusions is the same as the diameter of the inner end surface of the bottom 32a (the surface opposite to the bonding surface of the insulating substrate 11 in the second metal plate 31). The support mold 65 is formed with a recess 64 corresponding to the protrusion 63 for protrusion.

  Then, as shown in FIGS. 4C and 4D, the second metal plate 31 is placed on the support mold 65. Next, when the region surrounded by the inspection through-holes 33 is pressed with the convex mold 61 so that the front end edges of the protrusions 63 for the protrusions extend along the plurality of inspection through-holes 33, four inspection through-holes 33 are formed. On the other hand, one convex portion 32 is formed (second step).

  Since the convex portion 32 is pressed after the inspection through-hole 33 is formed, the inspection through-hole 33 is deformed. Specifically, when the second metal plate 31 is pressed by the convex mold 61, it is deformed and stretched. For this reason, the inspection through-hole 33 is distorted as compared with the case where the inspection through-hole 33 is formed after the convex portion 32 is formed. In the present embodiment, the inspection through-hole 33 is deformed so that its axial direction is inclined with respect to the axial direction of the convex portion 32.

Next, the bent portion 23 is formed on the first metal plate 21.
As shown in FIGS. 5A and 5B, a through hole 22 is formed in the first metal plate 21. The through hole 22 may be formed by any method such as press working or etching. By inserting a cylindrical member 69 having a diameter larger than the diameter of the through hole 22 into the through hole 22, the periphery of the through hole 22 is bent, and the bent portion 23 is formed.

Next, the first metal plate 21 and the second metal plate 31 are joined to the insulating substrate 11.
As shown in FIG. 6, the first metal plate 21 is bonded to the front surface 11 a of the insulating substrate 11, and the second metal plate 31 is bonded to the back surface 11 b of the insulating substrate 11. At this time, positioning is performed so that the bent portion 23 is inserted into the base material through hole 13 of the insulating substrate 11 and the convex portion 32 is inserted into the through hole 22 of the first metal plate 21. The bonding of the first metal plate 21 and the second metal plate 31 to the insulating substrate 11 is performed between the insulating substrate 11 and the first metal plate 21 and between the insulating substrate 11 and the second metal plate 31. This is performed by applying an adhesive and pressurizing the first metal plate 21 and the second metal plate 31 toward the insulating substrate 11 (third step).

  As shown in FIG. 7, a solder paste 28 as a conductive material is applied to the through hole 22 and its periphery in the first metal plate 21. The application of the solder paste 28 is performed in a state where the region other than the application region of the solder paste 28 in the base material through hole 13 is covered with a metal mask. That is, the surface of the first metal plate 21 opposite to the bonding surface with the insulating substrate 11 is flat, and a copper plate surface having no unevenness is secured, and the solder paste 28 can be printed in a desired region. it can. Further, in the solder paste 28 application step, the solder paste 28 is applied also in the electronic component placement region.

  Then, the applied solder paste 28 is heated in a furnace, so that the solder having fluidity flows into the through hole 22, the base material through hole 13, and the inspection through hole 33. Then, by hardening the solder, the interlayer connection portion 41 is formed inside the base material through hole 13 (fourth step). Thereby, the wiring board 10 by which the 1st metal plate 21 and the 2nd metal plate 31 were electrically conductive by the interlayer connection part 41 is manufactured.

Next, the effect | action of the manufacturing method of the wiring board 10 in this embodiment is demonstrated.
After processing the first metal plate 21 and the second metal plate 31, the respective metal plates 21 and 31 are joined to the insulating substrate 11. For this reason, it is not necessary to process the metal plates 21 and 31 in a state where the metal plates 21 and 31 are joined to the insulating substrate 11.

  In addition, the inspection through hole 33 is formed before the convex portion 32 is formed on the second metal plate 31. By forming the inspection through-hole 33, the inspection through-hole 33 becomes a region allowing deformation, and the rigidity of the second metal plate 31 is reduced. Since the rigidity of the second metal plate 31 is reduced, the second metal plate 31 is easily deformed when the convex portion 32 is formed.

Therefore, according to the above embodiment, the following effects can be obtained.
(1) Since it is not necessary to process the metal plates 21 and 31 in a state where the metal plates 21 and 31 are bonded to the insulating substrate 11, the metal plates 21 and 31 are not peeled off from the insulating substrate 11 along with the processing. .

  (2) When the convex portion 32 is formed, the inspection metal through-hole 33 is provided so that the second metal plate 31 is easily deformed, and the load applied to the convex forming die 61 (the convex portion projection 63). Less is. For this reason, the wear of the convex mold 61 is suppressed, and the life of the convex mold 61 is unlikely to be shortened.

  (3) Since the inspection through-hole 33 is provided at a position that becomes the base end of the convex portion 32, the rigidity of the second metal plate 31 is lowered by the inspection through-hole 33, and the convex portion 32 is easy to form.

  (4) Since the inspection through-hole 33 is provided at a position that becomes the base end of the convex portion 32, the inspection through-hole 33 is not easily embedded in the interlayer connection portion 41, and is due to the inspection through-hole 33. It is difficult to hinder the inspection of the solder filling state.

  (5) The inspection through-hole 33 is formed by the hole forming mold 51 before the convex portion 32 is formed. If the inspection through-hole 33 is formed after the convex portion 32 is formed, the convex portion 32 is formed, and the inspection through-hole 33 is formed in the bent portion, so that the hole forming mold 51 is easily worn. By forming the inspection through hole 33 prior to the convex portion 32, the inspection through hole 33 can be formed in the flat second metal plate 31. For this reason, the hole forming mold 51 is not easily worn, and the life of the hole forming mold 51 is not easily shortened.

  (6) With the inspection through-hole 33, it is possible to determine a bonding failure between the first metal plate 21 and the second metal plate 31. Specifically, when the inspection through hole 33 is not filled with solder, the solder cannot be visually recognized through the inspection through hole 33. Thereby, it can be determined that there is a bonding failure.

  (7) In the case of the substrate 100 described in Patent Document 1, the cylindrical member 106 is inserted into the through hole 105 in a state where the metal plate 102 is bonded to the ceramic plate 101, so that peeling of the metal plate 102 is suppressed. In addition, it is necessary to reduce the pressing pressure of the cylindrical member 106. On the other hand, in the present embodiment, when the bent portion 23 is formed on the first metal plate 21, it is not necessary to consider peeling from the insulating substrate 11, and thus it is not necessary to reduce the press pressure.

  (8) When forming the convex part 32, the inspection through-hole 33 is already provided. For this reason, when forming the convex part 32, the metal plate 31 in the convex part 32 can be extended, and the axial direction of the inspection through-hole 33 can be inclined with respect to the axial direction of the convex part 32. In this case, since the solder filled in the inspection through hole 33 can be inclined with respect to the thickness direction of the wiring board 10, the second metal plate 31 can be hardly peeled off from the insulating substrate 11.

(9) Since a plurality of convex portions 32 are formed, a plurality of interlayer connection portions 41 are formed. For this reason, the first metal plate 21 or the second metal plate 31 is not easily peeled off from the insulating substrate 11.
(Second Embodiment)
Hereinafter, a second embodiment of the wiring board will be described.

  As shown in FIG. 8, the wiring board 70 of the present embodiment has an interlayer connection 71 on the periphery of the insulating substrate 11. The first metal plate 72 is provided with a bent portion 73 that is bent so as to cover the periphery of the insulating substrate 11. The second metal plate 81 is provided with a convex portion 82 that protrudes so as to cover the periphery of the insulating substrate 11 together with the bent portion 73. The convex portion 82 faces the peripheral edge of the insulating substrate 11. An inspection through-hole 33 that penetrates in the thickness direction of the second metal plate 81 is provided at the base end of the convex portion 82. Solder is filled between the bent portion 73 and the convex portion 82 and the inspection through-hole 33, thereby forming an interlayer connection portion 71.

  When the convex portion 82 is formed on the second metal plate 81, the inspection through hole 33 is formed before the convex portion 82. For the wiring board 70 of the second embodiment, the same effect as that of the wiring board 10 described in the first embodiment can be obtained.

In addition, you may change embodiment as follows.
The inspection through hole 33 may be formed by drilling, etching, or the like.
The metal plate through hole may be other than the inspection through hole 33. That is, it may be a vent hole, for example, instead of determining a bonding failure. In the case of the gas vent hole, the gas at the time of soldering can be vented.

The interlayer connection 41 may be formed using other conductive material such as silver paste.
The convex portions 32 and 82 of the second metal plates 31 and 81 may be provided only at the end portions of the second metal plates 31 and 81 or other than the end portions of the second metal plates 31 and 81. It may be provided only in this area.

In the first embodiment, the first metal plate 21 is processed after the second metal plate 31 is processed. However, after the first metal plate 21 is processed, the second metal plate 31 is processed. May be.
○ The shape of the inspection through-hole 33 and the convex portions 32 and 82 may be a polygonal shape other than a circular shape.

The adhesive may not be applied but may be one in which an adhesive layer is previously formed on the surface of the insulating substrate 11 and the adhesive layer is liquefied by heating.
The interlayer connection portions 41 and 71 may not be provided.

The inspection through-hole 33 may not be inclined with respect to the axial direction of the convex portion 32.
The inspection through-hole 33 may be provided other than the base end of the convex portion 32.
A single convex portion 32 may be provided.

  -The convex part 32 may be formed by methods other than press work.

  DESCRIPTION OF SYMBOLS 10,70 ... Wiring board, 11 ... Insulating substrate, 11a ... Front surface, 11b ... Back surface, 13 ... Substrate through-hole, 21, 72 ... First metal plate, 22 ... Through-hole, 28 ... Solder paste, 31, 81 ... 2nd metal plate, 32, 82 ... convex part, 33 ... inspection through-hole, 41, 71 ... interlayer connection part, 50 ... mold for hole, 60 ... convex mold.

Claims (7)

A first metal plate provided on the surface of the insulating substrate; and a second metal plate provided on the back surface of the insulating substrate and having a convex portion formed thereon, the first metal plate and the convex portion. A method of manufacturing a wiring board facing each other,
A first step of forming a plurality of metal plate through holes in the second metal plate;
By forming one convex portion with respect to the plurality of metal plate through holes on the second metal plate, the axial direction of the plurality of metal plate through holes is inclined with respect to the axial direction of the convex portion. A second step,
And a third step of providing the first metal plate and the second metal plate on the insulating substrate so that the convex portion faces the insulating substrate. .   And a fourth step of forming an interlayer connection between the first metal plate and the second metal plate by filling a conductive material between the convex portion and the first metal plate. The method for manufacturing a wiring board according to claim 1.   3. The method of manufacturing a wiring board according to claim 1, wherein, in the first step, the plurality of metal plate through holes are formed at positions serving as base ends of the convex portions.   In the said 1st process, the said metal plate through-hole is formed by pressing, The manufacturing method of the wiring board as described in any one of Claims 1-3 characterized by the above-mentioned.   The wiring board according to any one of claims 2 to 4, wherein the metal plate through hole is an inspection through hole or a gas vent through hole for confirming a filling state of the conductive material. Manufacturing method.   6. The plurality of convex portions forming the interlayer connection portion are formed, and the convex portions are also formed in a region different from an end portion of the second metal plate. The manufacturing method of the wiring board as described in any one of them.   A first metal plate provided on the surface of the insulating substrate; and a second metal plate provided on the back surface of the insulating substrate and having a convex portion formed thereon, the first metal plate and the convex portion. And a wiring board facing each other,
  A plurality of metal plate through holes are formed in the second metal plate,
  One convex portion is formed for the plurality of metal plate through holes, and the axial direction of the plurality of metal plate through holes is inclined with respect to the axial direction of the convex portions,
  The wiring board, wherein the first metal plate and the second metal plate are provided on the insulating substrate so that the convex portion faces the insulating substrate.