JPH0250830A - Manufacture of electric laminated board - Google Patents

Abstract

PURPOSE:To prevent the occurrence of recess and protrusion on an outer layer circuit by manufacturing a primary laminated article in overlaying prepregs on a plural sheets of metallic plates provided with penetrating holes, and in overlaying prepreg on the outer surface of metallic plate of the outermost layer, and manufacturing a secondary laminated article in overlaying outer layer circuits thereon after polishing the surface. CONSTITUTION:A few sheets of metallic plates 2, 2 are overlaid via prepregs 3a, 3a, and a prepreg 3a is overlaid on the outer surface of metallic plate 2 of the outermost layer. Between each metallic plate 2, circuit plates 12, 12, which are formed with inner layer circuit such as one side surface printed-wiring board, both side surfaces printed-wiring board and multi-layered printed-wiring board, are set via prepregs 3a. These are heat and press-molded, and lamination-adhered then, and one part of resin 4 impregnated into prepregs 3a is flown, and then filled, into each penetrating hole 1 of the metallic plates 2. In the next place, after polishing the cured resin layer of the prepreg 3a on the surface of the first laminated article 7 and disappearing recesses, an outer circuit 6 is overlaid thereon via prepreg 3b, and besides, after a secondary laminating article 8 is manufactured by performing a heat and press mold, through holes 5 are made by punching work.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a multilayer electrical laminate using a metal plate as a substrate.

[Conventional technology]

In an electrical laminate using a metal plate 2 as a substrate, a perforated metal plate 2 is used to form through holes 5. That is, at the location where the through hole 5 is to be formed in the metal plate 2, the through hole 1, 1 is larger in diameter than the through hole 5.
... is provided, and these plural metal plates 2, 2...
By stacking them with the prepreg 3 interposed therebetween and performing heat and pressure molding, the resin impregnated in the prepreg 3 is cured, and each metal plate 2, 2... is laminated and bonded, and the resin impregnated in the prepreg 3 is bonded to the metal plate. 2 is injected into each of the through holes 1, 1, . . . and cured. At this time, as shown in FIG. 3(a), each metal plate 2 has a circuit board 12.12 such as a single-sided printed wiring board, a double-sided printed wiring board, or a multilayer printed wiring board.
. . , and overlay an outer layer circuit body 6 such as metal foil on the outermost layer, as shown in Fig. 3(b).
Connect the circuit board 12.12... to each metal plate 2.2...
・The outer layer circuit body 6 is laminated on the outermost layer. Then, in the part of the resin 4 filled in the through hole 1, a third
By drilling the through hole 5 as shown in FIG. 3(c), it is possible to form the through hole 5 in which insulation between the resin 4 and the metal plate 2 is ensured. Thereafter, by etching the outer layer circuit body 6 to form a circuit and plating the insides of the through holes 5, the multilayer metal plate 2 is used as a substrate, and the outer layer circuit of the outer layer circuit body 6 and the circuit board are formed. It is possible to finish a multilayer wiring board in which a multilayer circuit is formed with 12°12... inner layer circuits.

[Problem to be solved by the invention]

However, when forming as shown in FIG. 3(b), much of the resin contained in the prepreg 3 laminated on the outside of the outermost metal plate 2 flows into the through hole 1 of the metal plate 2. Therefore, as shown in FIG. 4, a depression 13 is generated on the surface in the area of the through hole 1, and the depression 13 extends to the outer layer circuit body 6 as well. When a metal foil such as copper foil is used as the outer layer circuit body 6, the recess 13 has a particularly large effect. Then, in this way, the outer layer circuit body 6 is provided with an opening 13.
If unevenness occurs due to this, it becomes impossible to apply etching resist accurately, causing problems such as making it difficult to precisely form circuits for the outer layer. The present invention has been made in view of the above points, and it is an object of the present invention to provide a method for manufacturing an electrical laminate that allows lamination of outer layer circuit bodies without causing unevenness. .

[Means to solve the problem]

In order to solve the above problems, the method for manufacturing an electrical laminate according to the present invention includes stacking a plurality of metal plates 2 provided with through holes 1 with prepregs 3a interposed therebetween, and forming a prepreg 3a on the outer surface of the outermost metal plate 2. are stacked and heated and press-molded to form prepreg 3.
The resin impregnated in the prepreg 3a is cured and each metal plate 2 is laminated and bonded, and the resin impregnated in the prepreg 3a is allowed to flow into each through hole 1 of the metal plate 2 to create a primary laminate 7. After polishing the surface of the primary laminate 7, the prepreg 3b
The outer layer circuit body 6 is layered via the prepreg 3b, and the resin impregnated into the prepreg 3b is hardened by heating and pressure molding to form the primary laminate 7.
A secondary laminate product 8 is created by laminating an outer layer circuit body 6 on the surface of the secondary laminate product 8, and then a through hole 5 is punched in the resin 4 portion within the through hole 1 in the secondary laminate product 8. That is.

[Effect]

Even if a dent is formed on the surface of the primary laminate 7 due to the resin flowing into the through hole 1 of the metal plate 2, this dent will be removed by polishing the surface of the second laminate 7, and the laminate will be removed in the secondary molding. The depression will no longer affect the outer layer circuit body 6.

【Example】

The present invention will be explained in detail below with reference to Examples. The metal plate 2 is made of a copper plate, an aluminum plate, or the like, and has through holes 1 formed therein at locations where through holes 5 are to be formed. The through hole 1 is formed with a diameter larger than that of the through hole 5. Further, the prepregs 3a and 3b are prepared by using glass cloth, paper, or the like as a base material, impregnating it with a thermosetting resin such as epoxy resin or Boliimi+ζ, and drying the impregnated resin. Here, the prepregs 3a and 3b include prepreg 3a used in -order lamination and prepreg 3 used in secondary lamination.
1), it is preferable that the prepreg 3a used in the second lamination contains an inorganic filler such as glass powder or alumina. Prepreg 3 used in secondary lamination
+3 does not need to contain a filler, but this does not negate its inclusion. Thus, in manufacturing an electrical laminate using the metal plate 2 as a substrate, the steps shown in FIGS. 1(a) to 1(e) can be followed. First, as shown in Figure tJIJ1 (a), the metal plates 2, 2...
・Layer several sheets of prepreg 3a on the outer surface of the outermost metal plate 2. At this time, circuit boards 12, 12, etc., each having an inner layer circuit formed thereon, such as a single-sided printed wiring board, a double-sided printed wiring board, or a multilayer printed wiring board, are set between each metal plate 2 via a prepreg 3a. By heating and press-molding this, the resin impregnated into the prepreg 3a is cured and the metal plates 2 and the circuit board 12 are alternately laminated and bonded, and a part of the resin impregnated into the prepreg 3a is cured. FIG. 1(b)
) The resin 4 is filled into the through hole 1 as shown in FIG. In the primary laminate 7 created in this way, of the resin contained in the prepreg 3a laminated on the outside of the outermost metal plate 2, the resin in the portions corresponding to the through holes 1 of the metal plate 2 is transparent. In order to flow into the hole 1, a depression 13 is generated on the surface of the primary laminate 7 in the area of the through hole 1, as shown in FIG. 2(,). Next, the cured resin layer of the prepreg 3a on the surface of this primary laminate 7 is polished. By polishing in this way, the second
As shown in figure (b), parts other than the hollow 13 are removed,
Kubami 13 will disappear. Polish and brush 13
After disappearing, an outer layer circuit body 6 is applied to the surface of this -order laminate 7 via a prepreg 31 as shown in FIG. 1(c).
The resin impregnated into the prepreg 3b is cured by heating and pressure molding, and the outer layer circuit body 6 is laminated and bonded to the surface of the primary laminate 7, thereby forming a secondary laminate as shown in FIG. 1(d). A laminate 8 is created. As the outer layer circuit body 6,
Metal foil such as copper foil is mainly used, but other materials such as a single-sided metal foil clad laminate, a single-sided printed wiring board, a double-sided printed wiring board, and a multilayer printed wiring board can also be used. In this secondary laminate product 8, the width 1 of the -th order laminate product 7 is
Since the outer layer circuit body 6 is laminated with the outer layer 3 removed, the outer layer circuit body 6 is laminated in a flat state as shown in FIG. 2(c). The electrical laminate according to the present invention can be obtained by drilling the through holes 5 in the secondary laminate 8 produced in this manner by drilling, punching, or the like. As shown in FIG. 1(e), the through hole 5 is formed with a smaller diameter than the diameter of the through hole 1 in the portion of the resin 4 filled in the through hole 1. Therefore, the through hole 5
Electrical insulation between the inner periphery of the metal plate 2 and the metal plate 2 is ensured by the resin 4. Note that some of the through holes 5 are formed to penetrate the metal plate 2 for grounding purposes. After processing the through hole 5 as described above, through hole plating is formed on the inner periphery of the through hole 5 with copper plating or the like, and the outer layer circuit body 6 is formed of metal foil or a metal foil covered laminate. Sometimes, by etching the metal foil to form an outer layer circuit, an electric circuit board is formed in which the multilayer metal plate 2 is the core and the inner layer circuit of the circuit board 12 and the outer layer circuit of the outer layer circuit body 6 are provided in multiple layers. Finish it. Here, since the prepreg 3a contains a filler, this filler is mixed in the resin 4 filled into the through hole 1 of the metal plate 2, and the through hole 5 is processed. At this time, the filler material is exposed on the inner circumferential surface of the through hole 5, and the inner circumferential surface of the through hole 5 becomes an uneven surface, which increases the adhesion of the through hole plating applied to the inner circumferential surface of the through hole 5. That's how it is.

【Effect of the invention】

As described above, in the present invention, a plurality of metal plates provided with through holes are stacked with prepreg interposed therebetween, and prepreg is stacked on the outer surface of the outermost metal plate, and the prepreg is impregnated by heating and pressure forming. The resin is cured and each metal plate is laminated and bonded, and the resin impregnated into the prepreg is flowed and filled into each through hole of the metal plate to create a primary laminate.Then, the surface of this primary laminate is polished, and then the prepreg is bonded. A secondary laminate product is created by overlapping the outer layer circuit body through the prepreg and curing the resin impregnated into this prepreg by heating and pressure molding and laminating the outer layer circuit body on the surface of the primary laminate product. ,
Even if depressions are formed on the surface of the primary laminate due to the resin flowing into the holes in the metal plate, these dents can be removed by polishing the surface of the secondary laminate. It is possible to prevent unevenness from occurring on the outer layer circuit body, and there is no possibility of problems occurring in circuit formation of the outer layer circuit body.

[Brief explanation of the drawing]

1. Figures (a) to (e) are cross-sectional views showing each step of manufacturing the electrical laminate according to the present invention, and Figures 2 (t), (b), and (c).
) is an enlarged cross-sectional view of a part of the same as above, and figure (a) is the same as figure 1 (b).
), FIG. 4(c) is an enlarged view of the mouth portion of FIG. 1(d), FIGS. 3(a) and (bHc) are cross-sectional views of the conventional example, and FIG. 4 is FIG. It is an enlarged view of part C of (b). 1 is a through hole, 2 is a metal plate, 3a and 3b are prepregs, 4 is resin in the through hole, 5 is a through hole, 6 is an outer layer circuit body, 7
8 is a primary laminate product, and 8 is a secondary laminate product.

Claims (1)

[Claims] (1) Layer multiple metal plates with through holes through prepreg, layer the prepreg on the outer surface of the outermost metal plate, and heat and pressure mold to harden the resin impregnated into the prepreg to harden each metal plate. A primary laminate is created by laminating and adhering the prepreg and filling each hole in the metal plate with resin impregnated with the prepreg.Then, after polishing the surface of this primary laminate, an outer circuit body is layered via the prepreg. A secondary laminate is created by heat-pressing molding to harden the resin impregnated into this prepreg and laminating an outer layer circuit body on the surface of the primary laminate. 1. A method for manufacturing an electrical laminate, comprising punching through holes in a resin part of the board.