JPS63159441A - Thermosetting resin laminate - Google Patents

Abstract

PURPOSE:To obtain inexpensively a laminate of a low dielectric constant, by adding a surface-treated fluorocarbon resin powder to a thermosetting resin, impregnating glass cloths with the mixture and laminate-molding the obtained prepregs. CONSTITUTION:5-250pts.wt. fluorocarbon resin powder subjected to physical and/or chemical surface treatment is added to 100pts.wt. thermosetting resin, and glass woven fabrics or glass cloths are impregnated with the obtained mixture to form prepregs. These prepregs, alone or as an inserted layer of a low dielectric constant, are laminate-molded to give a laminate. As said fluorocarbon resin powders, a fluoroethylene resin powder and a tetrafluoroethylene/hexafluoropropylene copolymer powder are desirable because of their low dielectric constants. Although the bases used are glass woven or nonwoven fabric, a glass nonwoven cloth of a high void content is desirable for impregnation with more fluorocarbon resin.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a laminate having a low dielectric constant (hereinafter abbreviated as ε).

(Prior Art) In recent years, printed wiring boards have been used in an extremely wide range of applications, and the characteristics required for the laminates constituting printed wiring boards have become increasingly diverse.Under these circumstances, there are many requirements regarding dielectric constant. Specifically, there is a strong demand for the development of a laminate with a low ε for the purpose of increasing signal transmission speed, that is, increasing computer calculation speed.

In order to meet these demands, in contrast to ordinary laminates made of thermosetting resins such as epoxy resins and base materials such as woven glass cloth, we have developed thermoplastics with low ε such as Teflon, polysulfone, polyethylene, and polybutadiene for the resin side. The introduction of resins and rubber-based elastomers, and the application of aramid cloth and quartz city from the -5 base material perspective have been considered.

However, the above-mentioned conventional laminates are inferior to ordinary laminates in terms of multilayer formability, dimensional changes during the processing process, drilling workability, reliability as a printed board, price, etc., and are not suitable for practical use. The drawback was that the range was extremely limited.

[Purpose of the invention]

As a result of research aimed at obtaining a laminate with a low ε, the present invention has been developed by dispersing surface-treated fluororesin powder in the laminate, thereby achieving a laminate with a low ε, drill workability, and reliability as a printed board. I got the knowledge that I could get a board,
Furthermore, based on this knowledge, various researches were carried out and the present invention was completed. The purpose is to provide a laminate at a low cost that has a low ε, can be processed into a printed wiring board in exactly the same process as a normal one, and has the same reliability as a normal one.

(Structure of the Invention) In the present invention, 5 to 250 parts by weight of fluororesin powder that has been subjected to physical surface treatment and/or chemical surface treatment is added to 100 parts by weight of thermosetting resin to form a glass woven fabric or glass non-woven fabric. The present invention relates to a thermosetting resin laminate characterized in that it is formed by laminating and molding a prepreg prepared by impregnating and drying (impregnating and drying) either alone or as a layer requiring a low ε.

The fluororesin powders used in the present invention include tetrafluoroethylene resin (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), various tetrafluoroethylene-perfluoroalkyl vinyl ether copolymers (
Fluororesin powders such as PFA), tetrafluoroethylene-ethylene copolymer, trifluorochloroethylene resin, etc.
PTFE, FEP, and PFA are preferable in order to lower ε. The particle size is preferably 0.5 to 30 μm from the viewpoint of impregnating the resin varnish into glass woven (or glass non-woven) material, mechanical strength of the laminate, hole wall roughness during drilling, etc.

The higher the amount of addition, the better in terms of lowering ε, but usually 5~
The amount is 250 parts by weight, preferably 10 to 200 parts by weight.

As the amount added increases, uniform dispersion into the resin becomes difficult, and interlayer adhesion strength after laminated molding, copper foil adhesion strength,
This is because a decrease in mechanical strength is observed, and conversely, if the amount added is small, ε will not be sufficiently low.

The present invention is characterized by using fluororesin powder that has been subjected to physical surface treatment and/or chemical surface treatment.

Physical surface treatment refers to surface treatment performed by physical means such as sputter etching, plasma treatment, corona treatment, ultraviolet treatment, and electron beam treatment, and the effect of this surface treatment improves adhesion. Chemical surface treatment is to improve adhesion by chemical treatments such as chemical etching, graft polymerization, osmic acid treatment, and iron pentacarbonyl treatment.

In addition, the effects brought about by these physical surface treatments and/or chemical treatments include the effect of generating functional groups or reactive active sites on the surface, the effect of generating fine irregularities on the surface, and forming a roughened surface. This results in improved adhesion.

This treatment improves the adhesive strength between the fluororesin powder and the thermosetting resin, and improves the properties of the laminate, especially its moisture absorption and moisture absorption heat resistance, as well as the roughness of hole walls during drilling and the staining of plating solution during plating. The embedding property and blowhole resistance are improved.

The substrate used in the present invention is a glass woven fabric or a glass nonwoven fabric, but a glass nonwoven fabric with more voids is desirable in order to contain a larger amount of fluororesin powder.

The thermosetting resin used in the present invention includes epoxy resin, polyimide resin, polyester resin, etc., and epoxy resin is suitable from the viewpoint of usage and processability.

Of course, various modified resins developed to lower ε may also be used.

Next, the method for making the laminate will be described.

The prepreg is prepared by mixing the treated fluororesin powder in a resin varnish, impregnating it into a glass woven fabric or glass nonwoven fabric and drying it. At this time, it is important to uniformly disperse the fluororesin powder into the resin varnish, and a mixing machine suitable for this purpose is the "Homo Mixer" manufactured by Tokushu Kika Kogyo.
and "Henschel Mixer" manufactured by Mitsui Miike Manufacturing Co., Ltd., and these mixers are used depending on the viscosity of the resin varnish, the amount of fluororesin powder added, etc.

The laminate can be obtained by laminating and molding a required number of prepregs prepared by the method described above. The structure of the prepreg in this case is determined depending on the required quality such as plate thickness, but if necessary, the general prepreg and the prepreg according to the present invention may be combined. For example, in a multilayer printed wiring board, the prepreg according to the present invention may be used only in layers requiring low ε, and ordinary prepreg may be used in other layers.

(Effects of the Invention) The laminate obtained by the present invention has the feature that ε is lower than that of ordinary laminates, and also has the feature that ε can be controlled by adjusting the type and amount of the fluororesin powder contained.

Furthermore, the laminate according to the present invention can be produced using normal laminate or composite material manufacturing equipment, and can be processed by drilling holes, soldering, etc. in the same way as normal laminates or composite materials. Therefore, it is suitable for manufacturing industrial printed wiring boards with low ε.

〔Example〕

In order to describe the contents of the present invention in detail, examples and comparative examples will be described below.

(Comparative Example 1) Epoxy resin (Epicoat 100 manufactured by Yuka Shell Epoxy)
1) Add 3 parts by weight of dicyandiamide to 100 parts by weight, mix, apply to a glass woven fabric with a thickness of 0.1 m and a weight of 105 y/m so that the thickness after lamination molding is 0.1 M, and dry to form a prepreg. Created. Next, add this prepreg to 16
Table 1 shows the properties of the laminate obtained by stacking the sheets and applying heat and pressing at 170'030 kg/ci for 120 minutes.

(Comparative Example 2) Epoxy resin (Epicoat 100 manufactured by Yuka Shell Epoxy)
1) Add 3 parts by weight of dicyandiamide to 100 parts by weight, mix, apply to quartz cloth with a thickness of 0.13 m and a weight of 100 g/rd so that the thickness after lamination molding is 0.13 m, and dry to create a prepreg. did. Next, stack 12 sheets of this prepreg and heat it to 170℃ and 30℃! J/cttt, 120
Table 1 shows the properties of the laminate obtained by heating and pressurizing.

(Comparative Example 3) Epoxy resin (Epicoat 100 manufactured by Yuka Shell Epoxy)
1) 60 parts by weight of PTFE powder (Lube, JL 5, manufactured by Daikin Industries, Ltd.) with an average particle size of 7 μm was added to a resin varnish prepared by adding 3 parts by weight of dicyandiamide to 100 parts by weight, and the mixture was mixed so as to be uniformly dispersed. Size 0.4, weight 8
0s/7rt glass non-woven fabric with a thickness of 0.4M after molding
A prepreg was prepared by coating and drying it so that it was as follows. Next, stack 4 sheets of this prepreg at 170℃, 30Kg/cIj
Table 1 shows the properties of the laminate obtained by pressurizing for 120 minutes.

(Example 1) Epoxy resin (Epico-1-10 manufactured by Yuka Shell Epoxy)
01) Add 3 parts by weight of dicyandiamide to 100 parts by weight and mix the resin varnish with PTFE with an average particle size of 7 um.
Add 60 parts by weight of the powder (Rubrozoli-5, manufactured by Daikin Industries) that has been treated with oxygen plasma as shown below and mix to uniformly disperse, and then mold into a glass nonwoven fabric with a thickness of 0.4 m and a weight of 80 y/end. A prepreg was prepared by coating and drying to a thickness of 0.4#.

Here, in the oxygen plasma treatment, the PTFE fibers were placed in a reaction vessel, the pressure inside the reactor was reduced, oxygen gas was introduced to replace air, and the pressure inside the vessel was set at 0°1'rorr.

Next, a high frequency power of 13.56 Htlz and 100 W was applied to the RF external electrode to perform plasma treatment for 60 minutes while stirring the PTFE fibers in the reactor.

Next, stack 4 sheets of this prepreg and make 170″C13QK
Table 1 shows the properties of the 1q laminate that was heated and pressurized for 120 minutes at J/ci.

Claims (1)

[Claims] 5 to 5 parts of fluororesin powder that has been subjected to physical surface treatment and/or chemical surface treatment to 100 parts by weight of thermosetting resin
Thermosetting material characterized by adding 250 parts by weight of a prepreg obtained by impregnating and drying a glass woven fabric or glass nonwoven fabric and inserting the prepreg alone or as a layer requiring a low dielectric constant, and then laminating and molding the prepreg. Resin laminate.