JP2544726B2 - Manufacturing method of multilayer printed wiring board - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a multilayer printed wiring board.

[Background technology]

The multilayer printed wiring board is generally manufactured as follows. First, an inner layer material (hereinafter, simply referred to as "inner layer material") in which an electric path is formed on at least one surface and a plurality of reference guides serving as marks for knowing the formation position of the electric path are provided, a resin-impregnated base material , A predetermined number of outer layer materials (metal foil or metal foil-clad plate) and laminating plates are positioned between each other with a pin and stacked to form a laminated body. The obtained laminated body is stacked in a plurality of stages, and hot pressed by a molding press to cure, and the pins and the laminating plate are removed and disassembled to produce a multilayer printed wiring board intermediate product. After that, the outer shape is roughly cut into a rough size and punched or manually cut using a reference hole such as a guide mark to obtain a multilayer printed wiring board.

As described above, the conventional manufacturing method includes resin-impregnated base material, metal foil,
It is necessary to repeat the steps of stacking the inner layer materials by positioning them with pins to form a laminate, stacking the obtained laminate in multiple stages, hot pressing with a molding press, curing and then disassembling. However, the workability was poor and the cost was increased.

Therefore, in order to solve such a problem, a belt-shaped laminated body including an inner layer material and an outer layer material having an electric path formed on at least one surface is continuously formed by lamination molding, and the laminated body is continuously transferred. A method for producing a multilayer printed wiring board by a so-called continuous method has been developed, in which a multilayer printed wiring board having a predetermined shape is obtained from the cured laminate after curing.

However, even in this continuous method, it is necessary to provide a plurality of reference guides that serve as a mark for knowing the formation position of the electric path of the inner layer material, but there is a circumstance that the shrinkage after curing is large in the laminated body, and the above-mentioned reference There is a problem that the dimension between guides is reduced due to shrinkage.

[Object of the Invention]

In view of the above circumstances, it is an object of the present invention to provide a method for producing a multilayer printed wiring board that can obtain a multilayer printed wiring board with less deviation between the reference guide dimensions before and after curing. .

[Disclosure of Invention]

In order to achieve the above object, the inventors have made various studies on the continuous method. As a result, molding direction (transfer direction)
On the other hand, the present invention has been completed by finding that the shrinkage is large because of the tension applied, but the shrinkage is small in the molding direction.

That is, the present invention applies a pressure roll to a belt-shaped laminated body including an inner layer material and an outer layer material in which an electric path is formed on at least one surface and a reference guide serving as a mark for knowing the formation position of the electric path is provided. After making continuous production by lamination molding while pressing with, and curing this laminate while continuously transferring it, press the reference guide to obtain a multilayer printed wiring board of a predetermined shape from the cured laminate. The gist is a method for manufacturing a multilayer printed wiring board, which is characterized in that a plurality of the printed wiring boards are arranged side by side in a direction parallel to the axial direction of the roll.

Hereinafter, the present invention will be described in detail with reference to the drawings showing an embodiment thereof.

FIG. 1 shows an embodiment of a method for manufacturing a multilayer printed wiring board according to the present invention. As you can see in the figure,
Band-shaped resin-impregnated base materials 1,1 and band-shaped metal foil (outer layer material) 2,2
And a large number of inner layer materials 3 ... The resin-impregnated base material 1 is made by impregnating a base material with a resin varnish. As the base material, paper, glass cloth, glass mat, glass non-woven fabric or the like is used. When asking for a glass cloth or the like, it is preferable to use a glass cloth that has been surface-treated with acrylic silane or the like. The resin varnish is usually made by diluting an unsaturated resin having an unsaturated bond such as unsaturated polyester resin, diallyl phthalate resin, vinyl ester resin with a vinyl monomer (crosslinking agent) and adding a polymerization initiator. Things are used. Epoxy resin, polyimide resin, etc. are also used in the same manner. Copper foil, aluminum foil, or the like is used as the metal foil. As shown in FIG. 2, the inner layer material 3 has an electric path 5 formed on at least one surface (both surfaces in this embodiment), and a reference guide 20 serving as a purpose for knowing the formation position of the electric path. Two of them are arranged side by side in the width direction. Further, the inner layer material 3 is wider than the resin-impregnated base material 1 and the metal foil 2, and holes 4 are provided at three portions of the protruding portion.

These resin-impregnated base material, metal foil, and inner layer material are continuously fed between a pair of upper and lower pressure rolls 6, 6. Inner layer material 3
As shown in Fig. 3, the pressure rolls 6,6
Feed it in the direction parallel to the width direction of. The resin-impregnated base material, the metal foil, and the inner layer material are pressure rolls such that the strip-shaped resin-impregnated base material 1 and 1 are arranged on both sides of the inner layer material 3 and the strip-shaped metal foils 2 and 2 are arranged outside thereof. The strip-shaped laminated body 7 is obtained by laminating and forming 6 and 6. Note that, in FIG. 3, the electric path 5 of the inner layer material is omitted.

After that, the obtained laminated body 7 is sent to a heating furnace 8 where it is continuously heated and cured. The cured laminated body 9 is attached to a die 10
It is continuously fed between the molds provided with the punch 11 and the punch 11. Die
Pins 12 are formed at 10 at the same intervals as the holes 4 of the inner layer material, and by inserting the holes 4 into the pins 12, the cured laminate 9 is positioned with respect to the mold. There is. In this way, the cured laminated plate 9 is positioned with respect to the mold, and the multilayer printed wiring board 13 having a predetermined shape is punched out from the cured laminated body by the mold.

As described above, a multilayer printed wiring board having an electric path formed inside and a metal foil on the surface can be obtained. After that, the metal foil on the surface is etched based on the reference guide to form an electric path or a through hole. If the dimensions between the reference guides are different before and after curing, for the internal electric circuit,
It may happen that surface electric paths and through holes are not formed at desired positions. However, in the manufacturing method of this multilayer printed wiring board, as described above, the reference guides should be arranged side by side in the direction intersecting the molding direction. Therefore, the shrinkage is small, and there is little deviation between the reference guide dimensions before and after curing.

The manufacturing method of the multilayer printed wiring board according to the present invention is not limited to the above embodiment. In the embodiment, the resin-impregnated base material is arranged on both sides of the inner layer material, and the metal foil is arranged on both outer sides thereof, but the resin-impregnated base material is arranged only on one side, and the metal foil is also the same. In some cases, only one sheet may be arranged on the outside, and even when the resin-impregnated base material is arranged on both sides, the metal foil may be arranged only on that side. Also,
In some cases, the inner layer material may be arranged in multiple stages such that the resin-impregnated base material is sandwiched between the inner layer materials. When the inner layer material is arranged in a plurality of stages, the reference guide may be provided only on the outermost inner layer material. The inner layer material may have a band shape.
The outer layer material may be a metal foil or a metal foil-clad plate as in the above-mentioned embodiment. An adhesive may be used instead of using the resin-impregnated base material.

〔The invention's effect〕

As can be seen from the above, the method for manufacturing a multilayer printed wiring board according to the present invention comprises an inner layer material in which an electric path is formed on at least one surface and a reference guide serving as a mark for knowing the formation position of the electric path is provided. In order to obtain a multilayer printed wiring board of a predetermined shape from the cured laminate after continuously forming a strip-shaped laminate including an outer layer material by lamination molding and curing the laminate while continuously transferring the laminate, Since a plurality of the reference guides are arranged side by side in a direction parallel to the axial direction of the pressure roll, a multilayer printed wiring board with little deviation between the reference guides before and after curing is obtained. be able to.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of a method for manufacturing a multilayer printed wiring board according to the present invention, FIG. 2 is a perspective view showing an inner layer material used in the embodiment, and FIG. 3 is a lamination molding process of the embodiment. It is a top view showing. 2 ... Metal foil (outer layer material), 3 ... inner layer material, 5 ... electric circuit 20 ... reference guide

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-60-119796 (JP, A) JP-A-61-120736 (JP, A) JP-A-55-78597 (JP, A) JP-A-60- 206089 (JP, A)

Claims (1)

(57) [Claims] 1. A belt-shaped laminated body including an inner layer material and an outer layer material, each of which has an electric path formed on at least one surface thereof and is provided with a reference guide serving as a mark for knowing the formation position of the electric path, by a pressure roll. It is made continuously by pressing and stacking, and the stack is continuously transferred and cured, and then the standard guide is used as a pressure roll to obtain a multilayer printed wiring board of a predetermined shape from the cured stack. A method for manufacturing a multilayer printed board, characterized in that a plurality of the printed wiring boards are arranged side by side in a direction parallel to the axial direction of.