JPS6140094A - Method of producing multilayer circuit board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for manufacturing a multilayer laminate that is inexpensive and has good punching workability.

BACKGROUND OF THE INVENTION In recent years, with the miniaturization of electronic devices, printed wiring boards have become denser. Therefore, even in the semi-industrial field where double-sided printed wiring boards were used, multilayer laminates having about four layers of printed wiring are beginning to be used. However, as the number of layers increases, punching becomes difficult, complex shapes cannot be processed, and the cost becomes high. was.

In view of the above points, it is an object of the present invention to provide an inexpensive multilayer laminate with good punching workability.

Means for Solving the Problems In order to achieve the above object, the present invention uses a glass cloth base epoxy resin printed wiring board 1 as an inner layer, and an epoxy resin-impregnated glass nonwoven fabric [l] 2 is in contact with both sides of the board. arrangement,
Furthermore, epoxy resin-impregnated glass nonwoven fabric [■] 3
, an epoxy resin-impregnated glass cloth 4 is used as the base material of the outermost layer and is molded under heat and pressure.
]3 is 4'0 to 1 per 100 parts by weight of epoxy resin.
It is characterized by containing 30 parts by weight of an inorganic filler. 5 is a metal foil that is integrally pasted on both sides.

In this case, it is desirable that the glass nonwoven fabric [■] 2 contains 40 parts by weight or less of an inorganic filler per 100 parts by weight of the epoxy resin.

Function: In the present invention, since the glass cloth-based epoxy resin printed wiring board 1 is used for the inner layer, the through-hole reliability and dimensional stability are good, and no displacement of the land holes occurs. In addition, the glass nonwoven fabric [■] 2 has good interlayer adhesion with the printed wiring board 1, and the glass nonwoven fabric [■] 3 contains an inorganic filler to improve through-hole reliability and dimensional stability. . The amount of inorganic filler contained in the glass nonwoven fabric [■] 3 is 40 parts by weight per 100 parts by weight of the epoxy resin.
If it is less than the critical portion, through-hole reliability and dimensional stability will deteriorate. On the other hand, if the content of the inorganic filler exceeds 120 parts by weight, the adhesion to the outermost glass cloth 4 becomes poor.

Incidentally, if the amount of inorganic filler contained in the glass nonwoven fabric [l]2 exceeds 40 parts by weight, interlayer adhesion with the printed wiring board 1 decreases and voids are likely to occur, which is not preferable.

Examples The glass nonwoven fabric (1), CII) used in the present invention is 2-
It is made by bonding glass fibers with a length of gQi+g with a binder such as epoxy resin, synthetic fiber, cellulose fiber, etc. Glass cloth is conventionally used as a base material for laminates. The inorganic filler may be silica powder, fired clay, glass beads, or the like, but is not particularly limited, but it is desirable that it imparts transparency to the laminate. Metal foils include copper foil, aluminum foil, nickel foil, and the like.

Next, the present invention will be explained in detail.

Example 1 Epicor) 1001 (Yuka Shell epoxy resin, m
p, 70C) 100 parts by weight (hereinafter simply referred to as "parts")
, phenol novolak (freefe/-#1% or less;
An epoxy resin composition containing 20 parts of softening point 90 tll'') and 0.3 parts of dimethylhensylamine was applied to a plain-woven glass cloth (G-07628 manufactured by Asahi Shavel) with a resin amount of 42%.
It was impregnated and dried to obtain a glass cloth prepreg.

20 parts of silica powder (average particle size 8 μ゛) was mixed with 100 parts of the above epoxy resin composition, and this was mixed with glass nonwoven fabric (
Made by Nippon Pi “Lean, weight 2゜gAtt) and resin amount 9
The glass nonwoven fabric was impregnated with 3 layers and dried to obtain a glass nonwoven fabric [11 sheets]. In addition, 100 parts of the same silica powder was mixed with 100 parts of the above epoxy resin composition, and this was applied to a glass nonwoven fabric (weighing 35 E/rrt') in an amount of 93
A glass nonwoven fabric (If) prepreg was obtained by impregnating and drying the glass to a uniform temperature.

Glass cloth base epoxy resin double-sided printed circuit board with copper foil blackened in advance (copper foil thickness 70μ, plate thickness 0.3
tart) for the inner layer, and the pressure was 5 kg/cI/11 for 5 minutes on both sides, then 25/$c-f for 2 minutes.
A multilayer laminate with a thickness of 1.61 was obtained by time-molding.

Example 2.3 and Comparative Examples 1-4 Sea urchin, the amount of silica powder A multilayer laminate was obtained in the same manner as in Example 1, with the exceptions.

Comparative Example 5 Example using all glass cloth without using glass nonwoven fabric
A multilayer laminate was obtained in the same manner as in Example 1.

Comparative Example 6 A multilayer laminate was obtained in the same manner as in Example i1 except that a glass nonwoven fabric base material was used as the inner layer double-sided printed wiring board.

The characteristics of each multilayer laminate obtained above are shown in Table 1.

Effects of the Invention As is clear from Table 1, according to the present invention, a multilayer laminate with good punching workability, excellent dimensional stability and through-hole reliability can be obtained, and glass nonwoven fabric is used in a part of the multilayer laminate. Its industrial value is extremely great because it can be manufactured at low cost.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the layer structure of a multilayer laminate according to the present invention. 1 is a printed wiring board, 2 is a glass nonwoven fabric CD, 3 is a glass nonwoven fabric (II), 4 is a glass cloth, and 5 is a metal foil.

Claims (1)

[Claims] 1. A glass cloth-based epoxy resin printed wiring board is used as the inner layer, and an epoxy resin-impregnated glass nonwoven fabric [I] is placed in contact with both sides of the board, and an epoxy resin-impregnated glass nonwoven fabric [II] is disposed on the outside thereof. ], and the outermost layer base material is a glass cloth impregnated with epoxy resin, which is molded under heat and pressure. 1. A method for producing a multilayer laminate, characterized in that it contains an inorganic filler. 2. The method for producing a multilayer laminate according to claim 1, wherein the glass nonwoven fabric [I] contains 40 parts by weight or less of an inorganic filler per 100 parts by weight of the epoxy resin.