JPS6293992A - Treatment of glass cloth - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for treating glass cloth for producing a printed wiring board with excellent heat resistance and one-dimensional stability.

(Prior Art) (Problem to be Solved by the Invention) Printed wiring boards using glass cloth are manufactured by treating the glass cloth with organic silane, impregnating it with varnish such as epoxy resin, and then subjecting it to heat treatment. A so-called prepreg in a semi-cured state is manufactured using the method, and after cutting it to a predetermined size, several sheets of this are stacked, and then copper foil is layered on one or both sides and heat pressed to create a copper-clad laminate. Start from that.

Devices mounted with printed wiring boards are becoming more densely packed and smaller, and along with this, there is a strong desire to improve the performance of printed wiring boards, such as heat resistance and dimensional stability. Print arrangement using glass cloth
It is said that the heat resistance and dimensional stability of the A substrate depend not only on the quality of the glass cloth, but also on the adhesion between the glass cloth and the varnish and the uniformity of the varnish impregnation.1 For example, if the varnish impregnation is insufficient. It is known that blistering (interfacial peeling) and measling (separation at intertwined points) occur at high temperatures.

It is also known that treating glass cloth with a silane coupling agent is effective for uniformly impregnating varnish and improving adhesion to glass and foam, and improvements in the type of silane coupling agent and blending conditions are needed. Although various methods have been attempted, satisfactory results have not yet been obtained with any of the methods.

Further improvements were desired.

The present invention eliminates these drawbacks of the prior art.

The purpose of this invention is to provide a printed wiring board that uses glass cloth and has excellent heat resistance and dimensional stability.

(Means for Solving the Problems) In order to solve these problems, the inventors of the present invention have made extensive studies and found that low-temperature plasma treatment is effective, and have arrived at the present invention.

In other words, the present invention relates to a method for treating glass cloth for printed wiring boards, which is characterized in that the glass cloth is treated with organic silane and then subjected to low-temperature plasma treatment.

The present invention will be explained in detail below.

The glass cloth referred to in the present invention includes E glass, C glass,
It is a fabric woven using long glass fibers with various glass component compositions, such as S-glass.

Refers to various types of fabrics such as plain weave, twill weave, and satin weave. What is the filament diameter of the long glass fiber used in the present invention?

The thickness is preferably from several microns to several tens of microns. The glass cloth used in the present invention is obtained by weaving a glass yarn obtained by combining a plurality of such long glass fibers through a warping process and a gluing process in the same manner as in ordinary textile manufacturing. Yes.The number of warps and wefts of glass cloth per unit length, j7, and weight per unit area are 1.Any material can be used as long as it complies with R3414 of the Japanese Industrial Standards and the American military standard (MIL standard). For example, the cloth thickness is 20 microns to 250 microns.

The weight is 30g per square meter, L is 300g, and T is 300g.
Preferably, the one in the u-circle. Further, as the glass component, E glass, which is a non-alkali glass, is desirable.

Normally, glass cloth has organic binders and glues attached to it that are necessary for weaving, and cannot be used as is as glass cloth for printed circuit boards, so these organic substances must be completely removed. Methods for removing organic matter include passing it through a furnace at about 600°C or heating it at 35°C.
Examples include a method in which the material is treated batchwise for several tens of hours in a furnace at 0 to 400° C. (this is called a heat cleaning treatment), and a quality treatment method in which a desizing agent is used.

The glass cloth from which organic matter has been removed by heat cleaning or the like is then treated with a surface treatment agent containing organic silane as a main component in order to improve adhesive strength and adhesion with the varnish for laminates. The organic silane used in the method of the present invention is represented by the general formula Rn5iX+, -n+. In this formula, X is any monovalent hydrolyzable group.

For example, halogen atoms, alkoxy groups and acylo-1
- is a group, and n is 1-3. When n is 1 or 2, X may be the same or different. Further, R is a group having at least one carbon atom, and the hydrogen atom bonded to the carbon atom is substituted with a reactive group such as an amino group, an ebor-1-cy group, a mercapto group, or a vinyl group. Good too. Furthermore, two or more organic silanes used in the present invention may be used in combination.

Typical organic silanes represented by the above general formula include 2
For example, γ-glyndoxybrobyltrimethoxysilane, r-mercaptopropyltrimethoxysilane, T-
Aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-1minopropyltrimethoxysilane,
N-β-(1)-vinylbenzylaminoethyl)-γ
- Amitub[]pyrtrimethoxysilane, r-(phenylami7))propyltrimethoxysilane, phenyltrimethoxysilane and methyltrimethoxysilane! -Xysilane and the like.

These organic silanes are usually prepared as an aqueous solution or a mixed solution of water and an organic solvent such as alcohols, ketones, glycol ethers, etc. at a concentration of about 0.01 to 5% by weight. It is used by adjusting the mind.

As a method for applying a surface treatment agent containing organic silane as a main component to the glass cloth, any known method such as a dipping method, a spraying method, or a gasification method can be employed. In the commonly used dipping method, for example, a glass cloth is immersed in an organic silane solution for several seconds at a temperature close to room temperature, and then twisted with a mangle.

Subsequently, dry curing is performed at 80 to 180° C. for several minutes to obtain a glass cloth to which approximately 0.01 to 2% by weight of organic silane is added.

In the method of the present invention, the organic silane-treated glass cloth is further subjected to low-temperature plasma treatment. Generally known treatment conditions are employed as the low and high plasma treatment conditions.

For example, the temperature is room temperature to 100 degrees, and the pressure is 0.
．． 1 to l torr, frequency from several to several tens of megahertz, output per unit area of electrode from 0.1 to], O
kiv/cIA, the processing time is preferably in the range of several seconds to several minutes.

This low-temperature plasma treatment can be performed either in 9 batches or continuously.

The glass cloth obtained by the method of the present invention is impregnated with varnish, dried, cured, prepregged, and then pressed to be processed into a laminate for printed wiring boards.

(Example) Next, the present invention will be described with reference to Examples.2 Performance evaluations of the present invention were carried out by the following methods: (1) Dimensional stability was evaluated according to JIS C-6486.

(2) Glass coated with impregnable triacetate-1 film Temporarily place a glass cloth, and measure the intensity of transmitted light 3 minutes after placing and covering the epoxy resin on this glass cloth, and the intensity of transmitted light in a blank test. was measured and evaluated by the transmittance calculated from the set of -(.

(3) Immerse the heat-resistant laminate in a boiling 2L 260'C solder bath at normal pressure for 30 seconds, and after taking it out, the interface between the laminate and the laminate will peel (blister), and the intertwined points of the gar floss will peel off ( 21) The boiling time for which 1 tll is generated is the heat resistance retention time.

The test piece is 50×501.

Example 1 Glass cloth subjected to heat cleaning treatment (warp G
751) 0 I Z, weft G751) 0 I Z ; warp density 44/1 inch, weft density 33/;

After immersing it in an aqueous solution of aminosilane O61%, it was squeezed uniformly with a mangle so that the volume of the solution was 30 parts by weight per part of the glass cloth. Next, dry in a hot air dryer.
Dry curing was performed at 50°C for 2 minutes to obtain an aminosilane-treated glass cloth.

Next, this glass cloth was placed in a vacuum container with parallel flat electrodes installed inside, and the residual pressure was evacuated using a vacuum pump.
The degree of vacuum is OLorr, 13.56 MIIz (7
) A high frequency wave was applied to the electrodes through a matching circuit from a high frequency power source at an output of 0.5 kW/cl to generate low temperature plasma, which was treated for 1 minute to obtain a plasma treated cloth. Next, NE was applied to this low-temperature plasma-treated glass cloth.
A prepreg consisting of 45 parts by weight of epoxy resin and 55 parts of glass cloth was prepared by impregnating it with an epoxy resin having a composition of FR-4 according to the MA standard.

A laminate was created by stacking 8 sheets of this prepreg and press-forming at 170"c for 1 hour.Then, the heat resistance and dimensional stability of the obtained laminate were measured.The results are shown in Table 1. Indicated.

Comparative Example 1 A laminated fabric was prepared except for the low-temperature plasma treatment step of Example 1, and the same items as in Example 1 were measured. Measurement results first
Shown in the table.

As is clear from Table 1, the glass cloth according to the present invention has better varnish impregnation properties than the conventional glass cloth, and the laminate using this glass cloth is different from the laminate using the conventional glass cloth. The heat resistance and one-dimensional stability were clearly improved compared to the above.

Example 2.3 The aminosilane of Example 1 was replaced with epoxysilane (Example 2)
Alternatively, a laminate was obtained by processing under the same conditions as in Example 1 except that glycidoxysilane (Example 3) was used instead. The measurement results are shown in Table 2.

Comparative Example 2.3 The aminosilane of Comparative Example 1 was replaced with epoxysilane (Comparative Example 2)
Alternatively, a laminate was obtained by processing under the same conditions as in Comparative Example 1 except that glycidoxysilane (Comparative Example 3) was used instead. The measurement results are shown in Table 2.

As is clear from Table 2, even if the silane coupling agent is changed, the impregnability of the varnish is improved, and the laminate plate after molding is improved. It can be seen that the one-dimensional stability is improved.

(Effects of the Invention) According to the method of the present invention, the impregnating property of the glass cloth with varnish is improved, thereby improving the heat resistance and two-dimensional stability of the printed wiring board.

Claims (1)

[Claims] (1) A method for treating glass cloth for printed wiring boards, which comprises treating the glass cloth with organic silane and then subjecting it to low-temperature plasma treatment.