JPH05162246A - Laminated sheet for printed circuit - Google Patents

Abstract

PURPOSE:To provide the title laminated sheet reduced in a dimensional shrinkage factor and warpage to a large extent in the same level as a glass fabric base material laminated sheet. CONSTITUTION:In a laminated sheet wherein each of surface layers is composed of a glass fabric impregnated with a thermosetting resin and an intermediate layer is composed of a glass nonwoven fabric impregnated with a thermoplastic resin containing 10-200wt.% of a filler, two glass fabrics impregnated with a thermosetting resin are used as each of the surface layers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed circuit laminate excellent in dimensional stability, warpage and workability.

[0002]

2. Description of the Related Art As a laminate for a printed circuit, a laminate made of a nonwoven glass fabric as an intermediate layer base material and a glass woven fabric as a surface layer base material and impregnated with an epoxy resin and heated and pressed (hereinafter referred to as composite laminate). Plates) have come to be used in large quantities. Laminates made by impregnating epoxy resin on a base material made only of glass woven fabric have excellent mechanical strength, dimensional stability, heat resistance, etc., and high reliability of through-hole plating, so electronic calculators, communication devices, electronic exchanges, etc. Is widely used in industrial electronic devices. However, since only the glass woven fabric is used as the base material, the punching process is not possible in the punching process, which is one of the processes for processing the printed circuit board, and the actual condition is that it is drilled. Further, even after the V-cut processing, since the glass woven fabric base material is used, the foldability is poor and the fibers of the glass woven fabric become beard-like from the end faces.

On the other hand, a composite laminated plate is economically cheaper than a glass woven fabric-based laminated plate, can be punched and punched, has an excellent V-cutting property, and has a good workability. However, the reliability, dimensional stability, and warpage of through-hole plating were evaluated to be lower than that of the glass woven fabric substrate laminate. The reason is that the glass woven fabric-based epoxy laminate has a composition in which the weight ratio of the organic epoxy resin to the inorganic glass woven fabric is about 40: 6.
It is 0. In this case, it is considered that the epoxy resin mainly makes various electrical performances excellent, and the glass woven fabric makes mechanical properties such as bending strength and dimensional stability favorable.

By the way, a general composite laminated board uses a glass non-woven fabric as a base material for the intermediate layer, and is liable to be distorted at the time of heat and pressure molding as compared with a laminated board using a woven base material. There is a problem of poor stability and warpage.

[0005]

SUMMARY OF THE INVENTION According to the present invention, by increasing the number of glass woven fabrics for the surface layer, a laminated board can be obtained without losing the excellent punching and V-cutting characteristics of the conventional composite laminated board. It is intended to provide a laminated plate having excellent dimensional stability and warpage during processing.

[0006]

According to the present invention, a surface layer is made of a glass woven fabric impregnated with a thermosetting resin, and the intermediate layer contains 10 to 200% by weight of a filler with respect to the thermosetting resin. A laminated board for a printed circuit, comprising a glass woven cloth impregnated with a resin, and two or more glass woven cloths each surface layer of which is impregnated with a thermosetting resin.

As shown in FIG. 1, a conventional composite laminated plate uses a glass non-woven fabric as a base material for an intermediate layer and a glass woven fabric for each surface as a surface layer. There was a problem that the dimensional stability and warpage in the laminated plate processing step were inferior to the laminated plate of the woven fabric substrate. The present invention solves this drawback. As shown in FIG. 2, by using two or more glass woven fabrics for each surface layer, the dimensional stability and warpage during processing can be improved by using the glass woven fabric. It can be improved to the same level as the laminate of the base material.

The glass woven fabric used in the present invention is 50
those up to g / m ² ~260g / m ² is preferred. Further, the glass woven cloth used is 210 g / m ² of glass woven cloth, and it is desirable that the number of sheets is 2 to 3 on each side, and if it is more than that, the punching workability and V-cutting property of the composite laminate are deteriorated, which is desirable. Absent.

[0009]

EXAMPLES The composition of the epoxy resin varnish is as follows.

[0010]

[Table 1]

The above materials were mixed to prepare a uniform varnish. Next, the varnish compounded for the surface layer was made into a glass woven fabric.
(Nittobo WE-18K-RB84 210g / m ² ) with a resin content of 42-
The glass woven fabric prepreg was impregnated and dried to 45% to obtain a woven prepreg. Subsequently, an inorganic filler having the following composition was added to 100 parts of the resin content of the varnish similarly mixed for the intermediate layer, and the mixture was stirred and mixed to prepare an inorganic filler-containing varnish. Silica (Tatsumori Ltd. crystallites VX-3) 25 parts of aluminum hydroxide _{(Al 2 O 3 · 3H 2} O) 70 parts of ultrafine powder silica (Shionogi Seiyaku Carplex) 5 parts glass nonwoven this inorganic filler-containing varnish A base material (manufactured by Nippon Vilene) was impregnated and dried so that the content of the resin and the inorganic filler was 90% to obtain a prepreg.

[0012]

Example: A glass non-woven fabric base material prepreg is used as an intermediate layer,
Two pieces of each of the above-mentioned glass woven prepregs are arranged on the upper and lower surface layers, and a metal foil is further laid on the prepreg and press-formed to obtain a thickness
A 1.6 mm copper clad laminate was obtained.

[0013]

COMPARATIVE EXAMPLE One glass woven prepreg of the above surface layer was arranged in each of the above examples, and a copper foil laminate having a thickness of 1.6 mm was obtained in the same manner as in the following examples. With respect to the obtained copper-clad laminate, the dimensional change rate (shrinkage rate), warpage, and V-cut property in the process of processing the circuit board were measured. The results are shown in Table 2.

[0014]

[Table 2]

(Measuring method) Dimensional change rate: Measured according to JIS C 6481. Warpage: Same as above V-cut property: A test piece with a width of 25 mm was prepared, and the layers of glass woven cloth on both surfaces were V-cut to give an intermediate layer of 0.5 mm.
left. Bending strength was measured with a span of 50 mm and defined as bending strength.

As is clear from Table 2, the copper-clad laminate having a large amount of glass woven surface layer has the same punching workability and V-cutting property as the conventional composite copper-clad sheet, and has dimensional stability and dimensional stability. It turns out that it is excellent in warpage.

[0017]

EFFECTS OF THE INVENTION The laminated sheet according to the present invention has a dimensional shrinkage rate and warpage significantly reduced as compared with the conventional composite laminated sheet by increasing the glass woven cloth as the surface layer, and is equivalent to the glass woven substrate laminated sheet. It becomes a level and is suitable as an industrial printed circuit board laminate.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a conventional composite laminated board.

FIG. 2 is a schematic sectional view of a composite laminate of the present invention.

[Explanation of symbols]

 1 Copper foil 2 Glass woven fabric impregnated with thermosetting resin 3 Glass non-woven fabric impregnated with thermosetting resin

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location H05K 1/03 H 7011-4E

Claims (1)

[Claims] 1. The surface layer is made of a glass woven fabric impregnated with a thermosetting resin, and the intermediate layer is made of a glass nonwoven fabric impregnated with a resin containing 10 to 200% by weight of a filler with respect to the thermosetting resin. A laminated board for a printed circuit, comprising two or more glass woven fabrics each surface layer of which is impregnated with a thermosetting resin.