JPH0571155B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a glass fabric for printed circuit boards in which the edges of the glass fabric do not become higher than the fabric when the edges of the glass fabric are prevented from fraying. The present invention will be described in detail with reference to the accompanying drawings. When weaving a glass fabric for printed circuit boards using a shuttleless loom, the warp threads 2 of the edges 1 on both sides of the fabric for printed circuit boards are thinner than the warp threads 3 of the woven fabric part, and the warp density is higher than that of the woven fabric part 4. A glass fabric 5 in which the selvedge part 1 is thinner than the woven fabric part 4 is woven, and a fraying preventive agent 6 is applied to the thin selvedge part 1 so that the selvedge part 1 has approximately the same thickness as the woven fabric part 4. As the anti-fray agent, an adhesive is used that hardly dissolves in the solvent used for impregnating the resin for printed circuit boards and does not soften at the drying temperature of the impregnated fabric. The anti-fray agent may be applied before or after cutting the ears, and may be applied by any convenient method such as solution type coating or hot melt type coating. (The two-dot chain line in the figure is the cutting position.) The amount of fray preventive agent to be applied is such that the fray preventive effect is sufficiently exerted on the ears where the thin thread is used, and the fray preventive agent is applied to the ears where the thin thread is used. The amount of resin is selected so that the thickness of the selvedge portion is substantially the same as the thickness of the fabric portion. I can tolerate it being a little thinner, but I don't want it to be thicker. Conventionally, glass fabrics for printed circuit boards woven using shuttleless looms have been coated with an anti-fray agent on the edges, which have the same structure as the textile fabric, as described in JP-A No. 52-34094, and then dried. A method is disclosed in which the outer ends of the ears are then cut off and rolled. When a long glass fabric manufactured by this method is rolled, the selvage part is thicker than the fabric, so the more the winding amount is, the higher the selvage is. However, the weft yarns in the woven fabric part were bent, resulting in a deterioration in quality. Furthermore, if the amount of anti-raveling agent applied is reduced to such an extent that no selvage occurs when the fabric is rolled, the anti-raveling effect will be insufficient, and the cut edges will be removed when the fabric is rolled or impregnated with resin and dried. There were disadvantages in that the warp threads frayed in some parts, got tangled in the rolls, or got mixed into the prepreg. Furthermore, if a sufficient amount of anti-fray agent is applied to the glass fabric manufactured by this conventional method to have a sufficient anti-fray effect, when the prepreg is cut to a desired length and stacked, the middle part of the prepreg will be cut due to the height of the edges. It had the disadvantage that it was curved and caused trouble when being transported by automatic machines. The present invention solves these drawbacks, and
The warp of the selvage is thinner than the warp of the woven fabric, and the warp density is increased, so the selvedge is always thinner than the woven fabric. By applying an anti-fray agent to this thinned selvage, it is possible to prevent the selvage from becoming thicker than the fabric part, which is the case in conventional fabrics, and all of the above-mentioned defects caused by the so-called high selvage can be corrected. A glass fabric for printed circuit boards that can fully exhibit the effect of preventing fraying and does not cause problems due to the height of the edges, both when winding the glass fabric into rolls and when producing prepreg using the glass fabric as a base material. Become. Furthermore, if an anti-fray agent is applied to areas where thin warp threads are closely arranged, the surface area available for adhesion will be larger than when thick warp threads are arranged, so the adhesion will be that much better, and even a small amount of resin will definitely prevent fraying. The effect will be obtained. For this reason, it is easy to make the part coated with the anti-fray agent the same thickness as the woven fabric part. In this way, if a printed circuit board is manufactured using a glass fabric with the same thickness for the fabric part and the edge part, the printed circuit board will always be a flat board, so even if copper foil is overlapped, there will be no wrinkles in the copper foil. It exhibits excellent practicality as a glass fabric for printed circuit boards, such as eliminating the possibility of defective products. A comparison measurement table between the glass fabric for printed circuit boards of the present invention and conventional products will be presented. Hereinafter, various embodiments of the present invention will be explained with reference to Examples, but the present invention is not limited thereto. Example A glass fabric for printed circuit boards was woven by the following method. Using a warping machine, 2172 ECG751/0 yarns (E is E glass, C is long fiber, G is monofilament thickness 751/0 is the count) are used as warp threads for the woven fabric part, and warp threads for the selvage part. 16 yarns of ECG1501/0 were used to wind the warp beam. This warp beam was mounted on a shuttleless loom and woven using ECG751/0 yarn for the weft. The fabric was heat cleaned at 350° C. for 100 hours, then treated with a 0.1% aqueous solution of γ-glycidoxypropyltrimethoxysilane and dried. Next, a band-shaped copolyester resin having a composition of terephthalic acid, isophthalic acid, adipic acid, and 1,4-butanediol, and an anti-fray agent having a softening point of 180° are added in a 5% methylene chloride solution in the warp direction of the selvage of the fabric. It was coated and dried. The coating width of the anti-raveling agent was approximately 6 m/m, and the amount of resin deposited was 6%. A slitter was used to cut the area near the center of the anti-raveling agent coated band. In order to see the effect of preventing fraying, we tested peeling off the warp at the end after cutting, but the sealing force was strong and that warp was cut. When 4,000 m of the glass fabric for printed circuit boards coated with the anti-fray agent produced as described above was rolled around a paper tube with a Shore hardness of approximately 80, no fraying, selvage height, wrinkles, or bending of the edges occurred. Furthermore, the fabric was impregnated with an epoxy resin and dried to produce a prepreg with a resin content of 37%. Comparative example Next, as a comparative example, both warp and weft are ECG75.
A glass fabric having the same construction of the fabric part and the selvage part was woven using a shuttleless loom using 1/0 yarn. An anti-fray agent was applied to the edges of this fabric in the same manner as in the example, and the fabric was cut with a slitter. The thickness of each of this woven fabric and prepreg produced by the same method as in the example was measured. A measurement table comparing the above examples and comparative examples is as follows.

[Table] The resin content of the anti-fray agent is 6% and the epoxy resin content is 39%.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; FIG. 1 is a perspective view of a part of a semi-finished product, FIG. 2 is an enlarged sectional view of a lug, and FIG. 3 is a perspective view of a part of a product. 1...Selvage part, 2...Warp thread, 3...Fabric part warp thread,
4... Textile portion, 5... Glass fabric, 6... Anti-raveling agent.

Claims (1)

[Claims] 1. When weaving glass fabric for printed circuit boards using a shuttleless loom, the warp for the edges on both sides of the fabric for printed circuit boards is thinner than the warp for the woven fabric, and the density of the warp is higher than that for the woven fabric. 1. A glass fabric for a printed circuit board, characterized in that a glass fabric is woven thinner than a woven fabric part, and an anti-fray agent is applied to the thin edge part so that the edge part has approximately the same thickness as the woven fabric part.