JPH01148520A - Manufacture of thermosetting resin laminated sheet - Google Patents

Abstract

PURPOSE:To contrive to reduce the number of sheets to be laminated and to improve the drilling performance of a laminated sheet by a method wherein thick glass cloth having specified specification is embrittled so as to make the bending strengths of the laminated sheet not larger than the specified value and, after that, impregnated with thermosetting resin varnish so as to produce prepreg in order to laminate the predetermined number of said prepreg and in addition pile up copper foil and finally form under heat and pressure. CONSTITUTION:Thick glass cloth, the thickness of which is 210-500mum and the weight of which is 250-500g/m<2>, is embrittled so as to make both the longitudinal and lateral bending strengths of a laminated sheet made therefrom not larger than 50kg/mm<2> in order to use in the laminated sheet. In the laminated sheet, which is manufactured by conventional method, troubles such as unsatisfactory wall roughness of drilled hole, curved hole and wear of drill are eliminated. As the thermosetting used, there is no restriction and may any resin such as epoxy resin, polyimide resin, phenolic resin, polyester resin or the like will do. For example, both the longitudinal and lateral bending strengths of a 1.6mm thick copper-clad epoxy resin laminated sheet, which is formed by piling up five sheets of prepregs obtained as mentioned above and 18mum thick copper foils attached on both sides of said prepreg piled under heat and pressure, are 50kg/mm<2> or less.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a new thermosetting resin laminate for industrial equipment and electronic equipment. The object of the present invention is to reduce the number of laminated prepreg sheets by increasing the thickness of the prepreg, reduce the number of man-hours, and obtain a thermosetting resin laminate with excellent drilling workability.

[Conventional technology]

BACKGROUND ART Epoxy resin copper-clad laminates using glass substrates have conventionally been used for manufacturing electronic equipment and industrial equipment.

In recent years, when drilling printed wiring boards, with the increase in surface mounting and high-density wiring, issues such as through-hole diameter reduction, hole position accuracy, and large bending have become problems. Also,
In order to improve productivity, drilling conditions have become stricter due to an increase in the tip rate (number of holes drilled per minute), and problems such as hole wall roughness, drill wear, and copper foil burrs have emerged.

Conventionally, the glass cloth used for thermosetting resin laminates for electronic devices and industrial equipment has a cloth thickness of 25.17 m.
-200/l m, weight 15g/m ~220g
/rd. The present inventors are considering making the glass cloth thicker in order to reduce the cost of the laminate, but the thickness is 210 mm.
μm~500μm, weight 250g/m~550g/
With CD glass cloth, the yarn of one wood is thick, and drilling with a drill places a large load on the drill during processing, which can cause the drill to break.A small diameter can cause the drill to bend, and a standard diameter can cause the hole wall to be rough. Become.

[Purpose of the invention]

The present invention improves the above-mentioned drawbacks, and has a cloth thickness of 21
0μm~500μm, weight 250g/rrl
The purpose is to provide a laminated plate with good drilling workability by subjecting thick cloth of ~550 g/m to embrittlement treatment to reduce the bending strength of the laminated plate to 50 kg/*12 or less.

[Structure of the invention]

The present invention has a thickness of 210 μm to 500 μm and a weight of 250 μm.
g / g - 550 g / g thick glass cloth, the bending strength of the obtained laminate is 50 kg / * "
It is characterized by embrittling it as shown below, impregnating it with thermosetting resin varnish such as epoxy resin, drying it to obtain a prepreg, laminating a predetermined number of sheets, overlapping copper foil, and molding under heat and pressure. This is a method for manufacturing a thermosetting resin laminate.

The feature of the present invention is that when a thick glass cloth with a thickness of 210 μm to 500 μm and a weight of 250 g/= to 550 g/n is made into a laminate, the bending strength is 5 in both the vertical and horizontal directions.
The purpose is to embrittle it so that it becomes less than 0 kg/mm2 before use.

If the glass cloth is made brittle so that the bending strength of the laminate is less than 50 kg/vanmm, the strength of the glass fibers becomes weaker and becomes brittle. Therefore, a laminate manufactured by a conventional method using such thick glass cloth is free from the problems of hole wall roughness, large bending, and drill wear after drilling.

Thickness 210. c+m ~500μm, weight 250g
/M~550g/rl thick glass cloth,
Compared to ordinary glass cloth with a thickness of 210 μm and a weight of 250 g/% or less, each strand is thicker, making the cloth stronger. On the other hand, since the glass cloth used in the present invention is brittle, even if the strands become thicker, the strength of the cloth can be weakened to the same level or lower than that of ordinary glass cloth. The problems of conventional laminates using thick glass cloth are virtually solved.

The degree of embrittlement at this time is preferably such that the bending strength of the laminate is 60 kg/25 mm or less in terms of glass cloth tensile strength.

The embrittlement method is not particularly limited, but includes heat treatment, chemical treatment, and the like. Glass cloth monofilament diameter is 7 to 12
μm is preferable, and the number of focused strands is preferably 1200 or less. Further, the number of vertical and horizontal implants is not particularly limited.

The thermosetting resin used in the present invention may be an epoxy resin, a polyimide resin, a phenol resin, a polyester resin, etc., and is not particularly limited.

〔Effect of the invention〕

According to the method of the present invention, the number of laminated prepregs can be reduced, costs can be reduced, and a thermosetting resin laminate with good drillability can be obtained.

〔Example〕

The present invention will be explained by examples.

Monofilament diameter is 9 μm, number of convergence is 800, number of vertical implants is 34 / 25 mm, number of horizontal implants is 27 / 25 m
, a glass cloth with a thickness of 290 μm and a weight of 330 g/ml is made brittle, and the tensile strength of the glass cloth is 50 kg/ml in length.
A thick cloth with a width of 25m1 and a width of 40kg/25+U was used.

Separately, epoxy resin (manufactured by Shell Chemical ■, product name BP-504)
5) An epoxy resin varnish consisting of 100 parts by weight (hereinafter referred to as "parts"), 47 parts of dicyandiamide as a hardening agent, 2-ethyl-4-methylimidazole as a hardening accelerator, and a solvent was prepared, and the glass cloth was impregnated and dried to remove the resin content. (RC)40
% prepreg was obtained. Copper foil (18 μm) was layered on both sides of these 5 sheets of prepreg, and heat and pressure molded to a thickness of 1'.
, 6 ms, bending strength 45 kg/m vertically, 36 horizontally
kg/w'' epoxy resin copper-clad laminate was obtained.

[Comparison Example 1] The same glass cloth as in Example 1 was made without embrittlement, and the tensile strength was 150 kg/25 (vertical) and 100 kg/width.
251 In a hazy state, it was impregnated with the same resin varnish as in the example and dried, and treated in the same manner as in the example to have a thickness of 1, 5 mm, and a bending strength of 55 kg/mm in length and 45 kg/mm in width.
An epoxy resin copper-clad laminate No. 2 was obtained.

[Comparison example 2] Monofilament 9μm, number of convergence 400, length 41 /
25 u+, width 32/25 x*, thickness 180
μm, weight 205 g/n (without embrittlement), tensile strength vertical 110 kg/2511, horizontal 90 kg
RC was impregnated with the same resin as in the example and dried under the condition of /25 degrees.
40% prepreg was obtained, 8 sheets of these prepregs were layered with copper foil (18 μm) on both sides, and heated and pressure molded to a thickness of 1.
．． 61m long, bending strength 58 kg/mm2 vertically, 4 horizontally
An epoxy resin copper-clad laminate weighing 5 kg/mm' was obtained.

The drill workability of the laminates obtained in Example 1, Comparative Example 1, and Comparative Example 2 was measured, and the results are shown in Table 1.

As is clear from Table 1, the performance of the laminate of the present invention is superior to that of a conventional laminated board using thick glass cloth or a laminate using conventional glass cloth.
It can also be seen that the cost is also lower.

Table 1 (Note) Measurement method ■)' IJ /L/diameter 0.4mmφ, number of revolutions 5700
Orpm.

Feed rate 2.0m/min, 3 sheets stacked, average value of large bending amount from 1st sheet to 3rd sheet up to 5000 shots ■Drill diameter 1.1 mmφ, rotation speed 6500 Orpm.

Feed rate 5.0m/min, 3 sheets stacked, 10000
Maximum roughness up to shot

Claims (1)

[Claims] Cloth thickness 210μm to 500μm, weight 250g
/m^2 ~ 550g/m^2 of thick glass cloth obtained by embrittling the laminate so that the bending strength becomes 50kg/mm^2 or less, impregnating it with thermosetting resin varnish such as epoxy resin, A method for producing a thermosetting resin laminate, which comprises drying to obtain a prepreg, and stacking a predetermined number of prepreg sheets and copper foil and molding them under heat and pressure.