JPH0592423A - Manufacture for prepreg and copper plated laminated sheet - Google Patents

Abstract

PURPOSE:To obtain a copper plated laminated sheet which has no generation of resin powder and is superior in an external appearance, by a method wherein at the time of cutting of prepreg, it is heated at a temperature of the softening point of resin or higher. CONSTITUTION:Phenolic resin or epoxy resin or polyester resin which is made into a varnishlike state is infiltrated into a base such as craft paper or glass woven fabric, dried and made into a semicured state by a regular method. This infiltrated base is preheated at the softening point of resin and cut off by a rotary cutter. With this construction, prepreg which does not generate resin powder by cutting is obtained. When the prepreg is heated, pressurized along with a copper foil and integrated by the regular method, a copper plated laminated sheet which is free from nick or damage and injury on the surface of the copper foil is obtained. In addition, the softening point is measured, by a method wherein only the resin is taken out from the prepreg, filled into a cappillary tube by 2-3mm, made to run along a thermometer within a sulfuric acid and raised rapidly to about 10 deg.C below the estimated softening point and then a temperature is raised by 1 deg.C in a minute.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copper clad laminate having excellent appearance and no dents or damages on the surface of the copper foil, and a method for producing a prepreg for obtaining the same.

[0002]

2. Description of the Related Art Conventionally, a prepreg is a long resin impregnated substrate obtained by coating, impregnating and drying a thermosetting resin varnish on a substrate such as kraft paper, linter paper, glass woven cloth, and glass non-woven cloth. It is manufactured by cutting a material (hereinafter, also referred to as a coated paper cloth) with a rotary cutter. Then, a required number of these prepregs are laminated, a copper foil is laminated on at least one surface according to the purpose of single-sided / double-sided copper clad, and heated, pressed and integrally molded to manufacture a copper clad laminate.

The prepreg obtained as described above is
Since it is in a semi-cured state, resin powder is generated during cutting and adheres to the cut surface or surface of the prepreg. This resin powder scatters when the prepreg is heated, pressed and integrally molded with the copper foil, and adheres between the stainless plate and the copper foil to cause a dent on the surface of the laminated copper foil. The dents on the surface of the copper foil have the drawback of causing circuit breaks and short circuits in the production of printed wiring boards. Recently, as electronic devices have become lighter, thinner, smaller, and finer, circuits are becoming finer and finer.
Scratches are a big problem.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above circumstances, and has a superior appearance and a copper clad laminate having no dents or damages on the surface of a copper foil, and a resin powder. An object of the present invention is to provide a method for producing a prepreg that does not generate.

[0005]

Means for Solving the Problems As a result of intensive studies to achieve the above-mentioned object, the inventors of the present invention achieved the above-mentioned object by generating a resin powder in a prepreg by preheating at the time of cutting. The inventors have found what can be achieved and completed the present invention.

That is, according to the present invention, when a base material is impregnated with a resin and dried, and the resin-impregnated base material is cut to produce a prepreg, the resin-impregnated base is cut at a temperature higher than the softening point of the resin. A method for producing a prepreg, which comprises preheating a material, and a prepreg cut by performing the preheating together with a copper foil, which is a copper-clad laminate characterized by being integrally molded under heating and pressure. .

The substrate used in the present invention includes kraft paper, linter paper, mixed paper, glass woven cloth, glass non-woven cloth,
Cellulose paper, aramid paper, etc. can be mentioned,
These may be used alone or in combination of two or more.

Examples of the resin used in the present invention include a phenol resin, an epoxy resin, a polyester resin and a polyimide resin, which may be used alone or in combination of two or more kinds. After these resins are dissolved in a solvent, a predetermined curing agent, curing accelerator, etc. are added to form a varnish, which is applied, impregnated and dried on a substrate to be in a semi-cured state.
The method of coating, impregnating, and drying the base material to obtain a semi-cured state is a conventional method, and is not particularly limited.

The method of preheating in the present invention is as follows:
Examples thereof include infrared rays, far infrared rays, hot air, hot rolls, and hot plates, and these can be used alone or in combination of two or more kinds. The most important thing in this preheating is heating above the softening point of the resin used. Cut the pre-heated coated paper cloth with a rotary cutter etc.
A prepreg free from the resin powder of the present invention can be obtained.

The softening point as referred to in the present invention means that the resin is scraped off from the prepreg so that the base material does not mix, or a sample obtained by taking out only the resin from the prepreg by a suitable method has a capillary tube with one end sealed (inner diameter approx. Layer thickness to 1mm, length 70-100mm)
Fill it up to 2-3 mm, follow the thermometer in the sulfuric acid bath, raise the temperature up to about 10 ° C faster than the expected softening point, and then increase it by 1 ° C per minute to measure the softening. Say a point.

The prepreg that has been cut by being preheated can be integrally molded by heating and pressing together with at least one side of the copper foil by a conventional method to manufacture the copper clad laminate of the present invention.

[0012]

The present invention can achieve the above object by preheating and cutting the prepreg. That is, at the time of cutting the prepreg, since it is heated above the softening point temperature of the resin, the generation of resin powder is eliminated when cutting, and the cut surface of the prepreg is fused, so that the generation of resin powder can be further suppressed completely. It is possible to manufacture a copper clad laminate having an excellent appearance.

[0013]

EXAMPLES The present invention will now be described with reference to examples, but the present invention is not limited to these examples.

Example A prepreg (resin softening point: 105 ° C.) cooled to room temperature at the exit of a coating machine after applying, impregnating and drying an epoxy resin varnish on a 180 μm thick glass woven cloth to make a semi-cured state
Was heated to 120 ° C. with hot air to soften the resin of the prepreg and cut with a rotary cutter to produce a prepreg with a resin amount of 42%. Eight sheets of this prepreg were stacked, and copper foil having a thickness of 18 μm was further stacked on the upper and lower surfaces of the prepreg, and heating, pressurizing and integrally molding were performed to manufacture a 1.6 mm-thick copper clad laminate.

Comparative Example In the example, except that the epoxy resin varnish was applied, impregnated and dried to be a semi-cured state, and then cut at room temperature,
A prepreg and a copper clad laminate were manufactured in the same manner as in the example.

With respect to the prepreg and the copper clad laminate produced in the examples and comparative examples, the defect rate such as generation of resin powder, dents and damage scratches, and appearance were tested. These results are shown in Table 1, but the present invention was excellent, and the effects of the present invention could be confirmed.

[0017]

[Table 1]

[0018]

As is clear from the above description and Table 1, the prepreg manufacturing method and copper clad laminate of the present invention are
It does not generate resin powder due to cutting from the prepreg, and has excellent appearance without dents or damage scratches on the copper foil surface when molded, and can be used in light, thin, short and compact electronic devices.

Claims (2)

[Claims] 1. When a substrate is impregnated with a resin and dried, and the resin-impregnated substrate is cut to produce a prepreg, the resin-impregnated substrate is preheated at a temperature higher than the softening point of the resin during the cutting. A method for producing a prepreg, comprising: 2. A prepreg obtained by impregnating and drying a resin on a base material and preheating the resin-impregnated base material at a temperature higher than the softening point of the resin and cutting it together with a copper foil by heating and pressurizing integrally. A copper-clad laminate characterized by being formed.