JPS63159442A - Thermosetting resin laminate - Google Patents

Abstract

PURPOSE:To obtain a laminated sheet of a low dielectric constant inexpensively, by adding a surface-treated fluorocarbon resin fiber to a thermosetting resin, impregnating glass cloths with the mixture and laminate-molding the obtained prepregs. CONSTITUTION:5-250pts.wt. fluorocarbon resin fiber 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 fibers, a fluoroethylene resin fiber and a tetrafluoroethylene/ hexafluoropropylene copolymer fiber are desirable because of their low dielectric constants. Although the bases used are glass woven or nonwoven fabrics, 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 for an extremely wide range of applications.
The characteristics required for the laminates constituting printed wiring boards are becoming 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 cloth from the -5 base material perspective have been considered.

However, the above-mentioned conventional laminates are inferior to ordinary boards in terms of multi-layer formability, dimensional changes during processing, drill workability, reliability as printed boards (product quality, price, etc.), and cannot be put to practical use. The shortcoming is that the scope is extremely limited.

[Purpose of the invention]

As a result of research aimed at obtaining a laminate with a low ε, the present invention was developed by dispersing surface-treated fluororesin fibers in the laminate, thereby achieving a laminate with a low ε, good drilling workability, and high 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]

The present invention is obtained by adding 5 to 250 parts by weight of fluororesin fibers that have been subjected to physical surface treatment and/or chemical surface treatment to 100 parts by weight of thermosetting resin, and impregnating and drying the glass woven fabric or glass nonwoven fabric. The present invention relates to a thermosetting resin laminate, characterized in that it is formed by laminating and molding a prepreg inserted alone or as a layer requiring a low ε.

The fluororesin fibers used in the present invention include tetrafluoroethylene resin (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), various tetrafluoroethylene-perfluoroalkyl vinyl ether copolymers (P
FA), fluororesin fibers such as tetrafluoroethylene-ethylene copolymer, trifluorochloroethylene resin, etc.
PTFE, FEP, and PFA are preferable in order to lower ε. In addition, the fiber diameter is 2 to 50 um, especially 2 to 15 μm.
is preferable, and the fiber length is preferably 10LtTrL to 10m1, especially 10μTrL to 5! rIIr1 is preferred. By setting the diameter and length of the fibers within the above range, ε can be lowered without impairing the mechanical strength of the laminate, drillability, or hole wall roughness.

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 fibers that have 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 chemical etching method.

Graft polymerization method, osmic acid treatment, iron vesica.

Adhesion is improved by chemical treatment such as rubonyl treatment. ; These treatments are usually performed on the fiber filaments and then cut into desired lengths, or after the fiber filaments are cut. 1 Through this treatment, the adhesive strength between the fluororesin fiber and the thermosetting resin is improved, and the properties as a laminate are improved, especially hygroscopicity, moisture absorption and heat resistance, hole wall roughness during drilling, and the plating liquid during plating. Penetration and blowhole resistance are improved.

The base material 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 fibers.

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 fibers in a resin varnish and impregnating and drying the mixture into a glass woven fabric or glass nonwoven fabric. At this time, it is important to uniformly disperse the fluororesin powder in the resin varnish and avoid breaking the fibers. Mixers suitable for this purpose include the "Homo Mixer" manufactured by Tokushu Kika Kogyo and the "Homo Mixer" manufactured by Mitsui Miike Seisakusho. Henschel mixer", and these mixers are used depending on the viscosity of the resin varnish, the amount of fluororesin fiber 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 1q laminate of the present invention has the advantage of having a lower ε than ordinary laminates, and also has the advantage of being able to control ε by adjusting the type and amount of fluororesin fibers contained.

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

〔Example〕

In order to describe the content 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 # and a weight of 105y/TIt, and dry so that the thickness after lamination molding becomes 0.1 shoe. Created prepreg. Next, 16 sheets of this prepreg were stacked and heated and pressed at 170'C30 at 3/ctri for 120 minutes. The properties of the resulting laminate are shown in Table 1.

(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 0.13M and a weight of 1009/m so that the thickness after lamination molding becomes 0.13m, and dry to create a prepreg. did. Next, add this prepreg to 1
Table 1 shows the properties of the laminate obtained by stacking two sheets and heating and pressing at 170° C. and 30 kg/ci for 120 minutes.

(Comparative Example 3) Epoxy resin (Epicoat 100 manufactured by Yuka Shell Epoxy)
1) Add 3 parts by weight of dicyandiamide to 100 parts by weight and mix the resin varnish with an average length of 1 m and an average diameter of 5 Q μn.
After adding 60 parts by weight of PTFE fibers and mixing to uniformly disperse, the prepreg was coated and dried on a glass nonwoven fabric with a thickness of 0°4# and a weight of 80y/m so that the thickness after molding was 0.4#. Created. Next, stack 4 sheets of this prepreg,
Table 1 shows the properties of the laminate obtained by pressurizing at 170°C and 130K'j/cnt for 120 minutes.

(Example 1) Epoxy resin (Epicoat 100 manufactured by Yuka Shell Epoxy)
1) Add and mix 3 parts by weight of dicyandiamide to 100 parts by weight of resin varnish, and add a mackerel with an average length of 1 and an average diameter of 50 μm.
Shun, which was prepared by adding 60 parts by weight of PTFE fibers treated with oxygen plasma as shown below and mixing them so that they were uniformly dispersed;
A prepreg was prepared by coating a glass nonwoven fabric with a thickness of 0.4 m and a weight of 80 y/m so that the thickness after molding was 0.4# and drying at T5.

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 internal pressure was set at 0°1 TOrr.

Next, a high frequency power of 13.56 MHz 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 heat to 770°C13'
Table 1 shows the properties of the laminate obtained by heating and pressing for 120 minutes.

Claims (1)

[Claims] 5 to 5 parts of fluororesin fibers subjected to physical surface treatment and/or chemical surface treatment per 100 parts by weight of thermosetting resin
A thermosetting material characterized by adding 250 parts by weight of the prepreg, which is 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.