JP3020700B2 - Glass fabric for printed wiring boards - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass fabric for a printed circuit board, and more particularly, to a glass fabric for a printed circuit board whose ears are not higher than the woven fabric when the ears are prevented from fraying.

[0002]

2. Description of the Related Art As a material for preventing frays of ears of a glass fabric for a printed wiring board, an anti-fraying agent is applied to the ears having the same structure as the woven fabric, and after drying, the outer ends of the ears are cut off. (Japanese Patent Laid-Open Publication No. 52-34094) is known.

However, when a long glass fabric obtained by this method is rolled, the ears are thicker than the woven fabric. There was a drawback that the weft in the woven fabric was bent and the quality was reduced.

[0004] Furthermore, the prepreg obtained from the glass fabric as described above is cut in the desired length and the middle of the prepreg is curved due to the height of the ear when it is stacked.
There was a disadvantage that troubles were easily generated.

On the other hand, if the application amount of the anti-fraying agent is reduced to such an extent that the ear height does not occur when rolled, the fraying prevention effect becomes insufficient, and when the woven fabric is rolled or the woven fabric is impregnated with resin. During drying, the warp at the cut end was frayed, and this portion was entangled with the roll or mixed in the prepreg.

[0006] As an improvement over the above drawbacks, as a warp yarn of both ears, a warp yarn thinner than the woven fabric warp is used, and the warp density is higher than that of the woven fabric so that the ear is thinner than the woven fabric. A glass fabric for printed wiring boards (Japanese Patent Application Laid-Open No. 61-188892) is known in which a thin antifraying agent is applied to the thin ear portion so that the ear portion has substantially the same thickness as the woven fabric portion.

However, when the above-mentioned woven fabric is wound into a roll, the tension balance differs due to the difference in the count between the ear warp and the fabric warp. For this reason, there has been a problem that wrinkles near the ears and bending of the cloth are likely to occur in each processing step.

[0008]

SUMMARY OF THE INVENTION As a result of intensive studies, the present inventors have found that a woven fabric having a thinner ear portion than a woven fabric portion is obtained by using a yarn having a smaller number of twists than the woven fabric warp yarn. Has been obtained, and it has been found that the above problem can be solved.

An object of the present invention is to prevent the ear from fraying, and the ear does not become higher than the woven fabric, and wrinkles and bends are formed near the ear even when rolled. It is an object of the present invention to provide a glass fabric for a printed wiring board without any problem.

[0010]

In the glass fabric for a printed wiring board according to the present invention, glass fibers having the same number as the warp of the woven fabric and having a smaller number of twists than the warp of the woven fabric are used as the warps of the ears on both sides. The ear portion is configured to have a woven structure thinner than the woven portion, and a fray preventing agent is applied to the ear portion so that the ear portion and the woven portion have substantially the same thickness.

In the present invention, the number of twists of the warp in the ear portion is made smaller than the number of twists of the warp in the woven portion, thereby making the ear portion a woven fabric thinner than the woven portion.

That is, since the warp in the ear portion has a smaller number of twists than the warp in the woven portion, the cross-sectional shape of the warp in the ear portion is a flattened ellipse as compared with the cross-sectional shape of the warp in the woven portion. Therefore,
In the glass fabric having the above-described configuration, the ear portion is always thinner than the woven portion.

Since the anti-fraying agent is applied to the thinned ear portion, the ear portion does not become thicker than the woven fabric portion. When such a glass fabric is rolled, wrinkles and cloth bends due to ear height are prevented. It does not happen. Further, since the warp in the ear portion has a small number of twists, the impregnation property of the anti-fray agent to the warp becomes good, and the anti-fraying effect is exhibited more than conventional products.

In the present invention, the warps in the ears are configured to have the same number and the same density as the warps in the woven fabric. Therefore, since the tension balance between the warp yarn of the ear portion and the warp yarn of the woven fabric portion is extremely good, even in the processing step after the roll winding, wrinkles and cloth bends near the ear portion due to this may occur. There is no.

The anti-fraying agent used in the present invention is such as to prevent fraying of the cut edge when the fabric is cut, and hardly dissolves in a solvent used at the time of impregnating a resin for a printed wiring board. Also, any adhesive that does not soften at the drying temperature of the impregnated fabric may be used.

The application of the anti-fraying agent may be performed before or after the cutting of the ears, and the application method may be any suitable method such as solution-type application or hot-melt-type application (two-dot chain line in FIG. 1). Is the cutting position.)

The amount of application of the anti-fraying agent is an amount which exhibits practically sufficient anti-fraying effect on the ear portion using the glass fiber having a small number of twists, and the thickness of the ear portion to which the anti-fraying agent is applied. The amount is such that the thickness is substantially the same as the thickness of the fabric portion.

[0018]

The present invention will be described below in detail with reference to examples.

Example A glass fabric for a printed wiring board was woven by the following method. ECG75-1 / 0 for warp for woven fabric by warping machine
2172 1.0Z yarns (E is E glass, C is long fiber, G is count, Z is twist direction), and 40 ECG75-1 / 0 0.7Z yarns are used for the warp for the ears And wound it up on a warp beam.

The warp beam was set on a shuttleless loom and woven using weft yarns of ECG75-1 / 00.7Z. The fabric was heat-cleaned at 360 ° C. for 65 hours, then treated with a 0.1% aqueous solution of γ-glycidoxypropyltrimethoxysilane, and dried.

Next, a polyetherimide resin was applied as a stripping inhibitor to the ears of the woven fabric in a 4% methylene chloride solution and dried. The application width of the anti-fraying agent is about 8mm
And the resin adhesion amount was 5%.

Subsequently, the vicinity of the center of the anti-fraying agent coated zone was cut with a slitter to obtain a glass fabric for a printed wiring board of the present invention.

In order to see the effect of preventing the obtained glass fabric for a printed wiring board from fraying, a tearing test of the warp at the end of the cut ear portion was carried out, but the sealing force was strong and the yarn was cut.

The woven fabric is applied to a paper tube with a Shore hardness of about 80.
Rolled for 4000m, but frayed and wrinkled
No texture bending occurred at all.

Further, the woven fabric is impregnated with an epoxy resin,
After drying, a prepreg having a resin content of 42% was prepared.

Comparative Example A yarn of ECG75-1 / 0.7Z was used as the weft, and both the woven portion and the ear portion were ECG75-1 as the warp.
Weaved on a shuttleless loom using a / 0 1.0Z yarn. In this glass fabric, the number of twists of the warp yarns in the woven fabric portion and the ear portion was 1.0 Z, which was the same.

Next, a fray preventing agent was applied to the ears of the woven fabric in the same manner as in the example, and the ears were cut with a slitter to obtain a glass woven fabric for a printed wiring board. Incidentally, the resin adhesion amount of the anti-fraying agent was 4%.

When the obtained glass fabric was roll-wound around a paper tube at a Shore hardness of 80, wrinkles and grain bends due to ear height occurred.

The above glass fabric is impregnated with an epoxy resin,
After drying, a prepreg having a resin content of 42% was prepared.

Table 1 shows the results of comparison between the above Examples and Comparative Examples.

[0031]

[Table 1]

[0032]

According to the glass fabric for a printed wiring board of the present invention, the ears are not frayed and the ears are not higher than the woven fabric. It does not cause any bending or texture bending. Further, since the tension balance between the ears of the warp and the woven fabric is good, no wrinkles or texture bends occur near the ears even in the processing step.

[Brief description of the drawings]

FIG. 1 is an enlarged cross-sectional explanatory view of an ear according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ear part 2 Ear part warp 3 Textile part 4 Textile part warp 5 Weft 6 Anti-fraying agent

Claims (1)

(57) [Claims] 1. A glass fabric for a printed wiring board, wherein glass fibers having the same count as the warp of the woven fabric and having a smaller number of twists than the warp of the woven fabric are used as the warp of the ears on both sides. A glass fabric for a printed wiring board, characterized in that it has a woven structure thinner than a woven portion, and a fray preventing agent is applied to the ear portions so that the ear portions and the woven portion have substantially the same thickness.