JPH04309529A - Production glass-fiber-reinforced electrical composite laminate - Google Patents

Abstract

PURPOSE:To produce the title laminate having a low coefficient of linear expansion and a low warpage by a continuous wet process. CONSTITUTION:A process for producing a glass-fiber-reinforced electrical laminate by a continuous wet process, wherein a glass cloth having a mean filament diameter of 9.6-10.2mum, a thickness of 180-200mum and a weight of 210-220g/m<2> (on the basis of metsuke unit (200-2000g/cm<2>) is used to form the outermost base layer, and a nonwoven cloth is used to form the inner base layer. In this way, a glass-fiber-reinforced electrical composite laminate having a low coefficient of linear expansion, a low warpage and excellent mechanical strengths can be obtained.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing glass fiber reinforced electrical composite laminates. Here, the electrical laminate refers to an insulating board used as a substrate for various electrical and electronic components, and a metal foil-clad laminate used as a printed circuit board.

0002

BACKGROUND ART In recent years, in response to the miniaturization of electronic devices, high-density mounting and automatic mounting of components onto printed wiring boards have been developed. Therefore, the quality required for the laminates used as substrates is becoming increasingly strict. Laminated plates are subject to heat during processing and during use of equipment on which components are mounted, and are susceptible to expansion and warping.

[0003] Glass fiber reinforced composite laminates are mainly used in office automation equipment and consumer equipment, sometimes in combination with flame-retardant resin. Until now, laminates have been produced using a batch dry method in which the base material is impregnated with resin varnish and dried to create a prepreg, which is stacked in the required number of sheets and press-molded. In recent years, a wet continuous method has been developed that uses resins such as unsaturated polyester resins and epoxy acrylate resins, which are liquid themselves and do not generate reaction by-products during curing, to continuously carry out the process from impregnation of the base material to lamination curing. It is attracting attention because of its high productivity.

However, when manufacturing a glass fiber-reinforced composite laminate by applying the wet continuous method, if glass cloth commonly used in the dry method is used as the glass cloth placed on both outer sides, the coefficient of linear expansion is large; It was found that the amount of warpage was large. Therefore, an object of the present invention is to apply a wet continuous method to produce a glass fiber composite laminate having a small coefficient of linear expansion and a small amount of warpage.

[0005]

[Disclosure of the Invention] The present invention provides a method for continuously transporting a plurality of base material rows in which glass cloth is arranged on at least both outer sides and a glass nonwoven fabric on the inner side, and the rows of base materials are individually separated. is impregnated with a curable resin that is liquid itself and does not generate reaction by-products during curing, the impregnated base materials are laminated and combined, a cover sheet and/or metal foil is laminated, and after continuous curing, the desired dimensions are obtained. In the method for manufacturing a glass fiber-reinforced electrical composite laminate including a step of cutting, the glass cloth base material has filament average diameters of 9.6 to 10.2μ.
m, thickness 180-200μm, basis weight 210-220
Provided is a method for manufacturing a glass fiber reinforced electrical composite laminate, characterized in that it is a glass cloth of g/m2. According to the present invention, it is possible to obtain a laminate having a small coefficient of linear expansion and a small amount of warpage, and excellent mechanical strength.

[0006]

[Preferred Embodiment] Glass cloth is a yarn made of a large number of thin glass filaments, such as satin weave, plain weave,
It is a general term for cloth that is woven vertically and horizontally in various weaving methods, such as plain weave and twill weave. The glass cloth used in the present invention has an average diameter of filaments of 9.6 to 10.2 μm, a thickness of 180 to 200 μm, and a basis weight of 21 μm.
It is a glass cloth with a weight of 0 to 220 g/m2. For example, a yarn made by bunching around 400 filaments is
A plain weave glass cloth is used, which is woven with 0 to 42 pieces/25 mm and 31 to 37 pieces/25 mm horizontally.

[0007] Glass nonwoven fabric is a long sheet-like glass nonwoven fabric (glass paper) made by wet-forming glass fibers with a diameter of 1 to 20 μm dispersed in water and using acrylic resin, polyvinyl alcohol, epoxy resin, or melamine resin as a binder. There are also glass-mixed papers made of cellulose fibers and glass fibers, synthetic fibers such as polyester, and glass non-woven fabrics containing rayon, asbestos, rock wool, etc.

For the glass paper used in the continuous lamination method, it is preferable to use a large number of thin base materials in order to reduce variations in plate thickness. However, thin glass paper generally has low strength, and cutting accidents may occur during continuous conveyance. To prevent this, the core layer glass paper should have a filament diameter of 8 to 10 μm.
It is more preferable to use a glass paper prepared by mixing two types of glass fibers, each having a diameter of 5 to 7 μm and a length of 10 to 15 mm. This is because such glass paper has sufficient tensile strength even if it is thin.

[0009] In carrying out the present invention, except for using the above-mentioned glass cloth for at least both outer base material layers and glass nonwoven fabric for the inner base material layer,
5-4838, 56-98136, etc. can be applied.

One of the characteristics of the wet continuous method is that a curable resin that is liquid itself and does not generate reaction by-products upon curing is used as the resin for impregnating the base material. Such resins include unsaturated resins such as unsaturated polyester resins, epoxy acrylate resins, polyester acrylate resins, diallyl phthalate resins, mixtures thereof, and epoxy resins. Mixtures of halogen-containing resins, such as bromine-containing unsaturated polyester resins and epoxy acrylate resins, may be used, and flame retardant aids such as antimony trioxide may be included.

After the substrates conveyed in parallel are individually impregnated with the resin, these substrates are laminated and combined, and a metal foil such as copper foil is applied to both or one side of the laminate after curing. It becomes an integral part. The surface not covered with metal foil is covered with a cover sheet such as a polyester film, which is peeled off after curing. After that, it is cut to a predetermined size and subjected to post-curing, if necessary. The manufacturing method of electrical laminates by the wet continuous method is described in the patent application of the applicant cited above, especially in the Japanese Patent Application Laid-open No. 5
6-98136 and will not be discussed further. The invention is illustrated below with examples and comparative examples.

Example 1 Glass cloth having a thickness of 190 μm, an average filament diameter of 9.8 μm, and a basis weight of 215 g/m2 was used for the upper and lower outermost layers, and a glass fiber having a diameter of about 9 μm and a length of 12 μm was used in the middle. Two sheets of glass paper with a basis weight of 50 g/m2 are arranged, and while being conveyed continuously, they are individually impregnated with a curable resin liquid and then combined to form an epoxy resin adhesive layer with a thickness of 4.
After laminating copper foil with a thickness of 18 μm coated to 0 μm on both sides, it was continuously passed through a tunnel type curing furnace.
It was thermally cured at 00° C. for 15 minutes and at 150° C. for 10 minutes to produce a double-sided copper-clad unsaturated polyester laminate having a thickness of 1.6 mm by a continuous manufacturing method. The resin for impregnation was 70 parts by weight of a flame-retardant unsaturated polyester resin (brome content: 14 parts by weight).
%), 30 parts by weight of epoxy acrylate resin, 4 parts by weight of antimony trioxide, and 1 part by weight of benzoyl peroxide were used.

Example 2 Example 1 except that three sheets of mixed nonwoven fabric having a basis weight of 33 g/m 2 and glass fibers having a diameter of approximately 9 μm and a length of 12 mm and glass fibers having a diameter of approximately 6 μm and a length of 12 mm were used.
A double-sided copper-clad laminate with a thickness of 1.6 mm was manufactured by the same operation as above.

Comparative Example 1 Same as Example 1 except that the upper and lower outermost layers were glass cloth with a thickness of 180 μm, an average filament diameter of 9.5 μm, and a basis weight of 200 g/m2. A double-sided copper-clad laminate with a thickness of 1.6 mm was produced by the operation.

Comparative Example 2 When a non-woven fabric made of glass fiber with a diameter of about 9 μm and a length of 12 mm and a basis weight of 33 g/m2 was used, the back tension was lowered to avoid cutting during conveyance, so the non-woven fabric meandered. A laminate with no problems in appearance could not be obtained. The performance of the laminates of Examples and Comparative Examples is shown in the table below.

[Table 1]

Method for evaluating warpage after heating The laminate manufactured by the above method was
The copper foil on one side is completely removed by etching. After that, heat treatment was performed at 170°C for 30 minutes, and then the side with the remaining copper foil was placed on a glass flat plate facing down.The distance from the four corners of the laminate from the glass flat plate was measured and the maximum value was calculated. I asked for it.

Method for Measuring Plate Thickness Variation The thickness of the standard size plate produced by the above method was measured at arbitrary 20 points using a micrometer, and the difference between the maximum value and the minimum value was defined as the plate thickness variation.

[0018] Linear expansion coefficient measurement method: Rigakusha TMA8140 (heating rate 2°C/min)
Calculated based on the results measured in .

Claims (2)

[Claims] Claim 1: A glass cloth is arranged on at least both outer sides,
While continuously conveying a plurality of base material rows with glass non-woven fabric arranged on the inside in parallel, the base material rows are individually impregnated with a curable resin that is itself liquid and does not generate reaction by-products upon curing. , a method for producing a glass fiber reinforced electrical composite laminate comprising the steps of laminating and combining impregnated base materials, laminating a cover sheet and/or metal foil, curing continuously, and then cutting into desired dimensions; The glass cloth base material has a filament average diameter of 9.6 to 10.2 μm and a thickness of 18
A method for producing a glass fiber reinforced electrical composite laminate, characterized in that the glass cloth is 0 to 200 μm and has a basis weight of 210 to 220 g/m2. 2. The method for manufacturing a glass fiber reinforced electrical composite laminate according to claim 1, wherein a glass nonwoven fabric prepared by mixing two types of glass fibers with filament average diameters of 8 to 10 μm and 5 to 7 μm is used as the inner glass nonwoven fabric. .