JPH03110139A - Preparation of laminate of base material made of heat-resistant thermoplastic fiber fabric - Google Patents

Abstract

PURPOSE:To prevent a base material from cutting when it is coated and to prepare a laminated sheet of a base material made of a heat-resistant thermoplastic fiber with low dielectric constant and high heat resistance by using a mixed woven base material consisting of a specified heat resistant thermoplastic fiber and a glass fiber. CONSTITUTION:A base material prepd. by weaving a fabric using a glass fiber as a part of warps and a heat-resistant thermoplastic fiber with a m.p. of 270 deg.C or higher as remaining part of warps and wefts is coated with a thermosetting resin to prepare a prepreg. Parts of this prepreg contg. no glass fiber are cut in a specified dimension and required sheets of the cut prepregs are put in layers and if necessary, copper foils are placed on both faces or one face of the obtd. laminate and a laminated sheet is prepd. by heat-pressing.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for manufacturing a laminate for printed wiring boards that has a low dielectric constant (and excellent heat resistance), and in particular, Concerning a manufacturing method that does not cut.

[Conventional technology]

In recent years, in order to improve signal transmission speed as computers have become faster in processing, there has been a demand for laminates with a low dielectric constant.

Conventionally, E glass fiber cloth, D glass fiber cloth, quartz glass fiber cloth, aromatic boria hammered fiber cloth, etc. have been used as base materials for low dielectric constant laminates. In order to further lower the dielectric constant, they proposed the use of heat-resistant thermoplastic fibers as a base material in Japanese Patent Application No. 63-322437.

Examples of heat-resistant thermoplastic fibers include polyether ether ketone (hereinafter abbreviated as PEEK) fiber and polyetherimide (
(hereinafter abbreviated as PEI) fiber, polyphenylene sulfide (hereinafter abbreviated as PEI), polyphenylene sulfide (
These fibers have a melting point of 270°C or higher and are not only highly heat resistant, but also have a low dielectric constant of 3.1 to 3.5, and are used as base materials for the above-mentioned laminates. It is suitable as

[Problem to be solved by the invention]

However, when producing a prepreg by impregnating the above-mentioned heat-resistant thermoplastic fiber fabric base material with a thermosetting resin and passing through a solvent heating and drying process called a coating process, there are cases where the force for pulling and moving the base material is large, or when the coating process There is a problem that the base material breaks when the temperature is high.

The present invention was made in view of the above situation, and produces a heat-resistant thermoplastic fiber cloth base laminate that prevents the base material from being cut during coating, has a low dielectric constant, and has high heat resistance. The aim is to provide a method for doing so.

[Means to solve the problem]

As a result of conducting studies to solve the above problem, the present inventors discovered that the above object could be achieved by using a mixed fiber base material of a specific heat-resistant thermoplastic fiber and glass fiber,
The present invention has now been completed.

That is, the method for producing a heat-resistant thermoplastic fiber cloth base laminate of the present invention uses glass fiber for a portion of the warp threads, and heat-resistant thermoplastic fibers having a melting point of 270°C or higher for the remaining warp threads and weft threads. A prepreg is produced by coating a thermosetting resin on a base material woven into a cloth shape, cutting the part of this prepreg that does not contain glass fibers to a specified size, stacking the required number of cut prepregs, and creating a prepreg as needed. The method is characterized in that copper foil is placed on both sides or one side of the laminate obtained according to the method, and the laminate is manufactured by heating and pressing.

In the present invention, heat-resistant thermoplastic fibers have a melting point of 270°C.
These are the above thermoplastic fibers. When using general-purpose thermoplastic fibers with a melting point of less than 270°C, soldering heat resistance test (260°C
(floating in a solder bath at ℃), blistering occurs.

Examples of such heat-resistant thermoplastic fibers include polyetheretherketone fibers, polyetherimide fibers, and polyferene sulfide fibers. The chemical structural formulas of each are shown below.

Polyetheretherketone; Polyetherimide; Polyphenylene sulfide; The melting point of polyetheretherketone fiber is 334°C, the glass transition temperature is 143°C, and the dielectric constant is 3.2
It is. The melting point of polyetherimide fiber is approximately 320°C
, the glass transition temperature is 217°C, and the dielectric constant is 3.1. Polyphenylene sulfide fibers have a melting point of 285°C, a glass transition temperature of about 85°C, and a dielectric constant of 3.5.

These heat-resistant thermoplastic fibers have a fiber diameter of 5 to 50 μm, preferably 10 to 30 μm. If the fiber diameter is too small, the threads will break easily, and if it is too thick, the base material will be too thick, making it unsuitable for use in laminates.

Examples of the glass fibers used in the present invention include E glass fibers, S glass fibers, D glass fibers, and quartz glass fibers. The glass fibers are preferably used as yarns in bundles as the warp threads of the substrate.

The glass fibers are preferably used as warp yarns at both ends or in the center of the base material in the longitudinal direction. When cutting the prepreg, the position may be any position as long as it can be cut into a predetermined size so as not to contain glass fibers. The amount of glass fiber used is usually 2 to 10 (yarns) sufficient as long as it can withstand the tension during coating. Further, the thickness of the glass fiber yarn is preferably such that the thickness of the base material does not increase.

Thermosetting resins used in the present invention include low dielectric constant resins such as epoxy resins, bismaleimide resins, and fluororesins.

These thermosetting resins are applied to a base material to produce a prepreg. Prepreg can be produced by dissolving thermosetting resin in a solvent to form a face, impregnating it into the above base material, then heating and drying to remove the solvent to obtain prepreg, or by heating and melting the thermosetting resin without a solvent. This is carried out by a method such as allowing the base material to be impregnated.

The part of the prepreg obtained in this way that does not contain glass fibers is cut to a predetermined size, the cut prepreg is laminated in the required number of sheets, and copper foil is placed on both or one side of the obtained laminate as necessary. Then, heat and pressure is applied to produce a laminate. When cutting, it is not preferable to include glass fibers in the prepreg because the dielectric constant of that part will increase. or,
Due to the difference in thermal expansion coefficient between the glass fiber and the heat-resistant thermoplastic fiber, microcranks may form in the thermosetting resin, which is also undesirable.

In the present invention, the heating temperature in the above step is in the range of 150°C to 270°C, and is set in consideration of the curing temperature of the thermosetting resin and the melting point of the heat-resistant thermoplastic fiber. Further, the pressurizing pressure in the above step is in the range of 5 to 100 kgf/(-d, and is set in consideration of the melt viscosity of the resin, etc.

[Effect]

According to the present invention, the reason why the base material cannot be cut during the coating process is that the tensile strength of glass fiber is significantly higher than that of heat-resistant thermoplastic fiber.
The tensile strength of the fiber is 84 kgf/mm”, 32 kgf/a+m” for PEI fiber, and 61 kgf/a+m” for PPS fiber.
kgf/afar", whereas the tensile strength of E glass fiber is as high as 350 kgf/m2.

Furthermore, the dielectric constant of the laminate obtained by the present invention is low because only heat-resistant thermoplastic fibers with a low dielectric constant are used as the base material, and the dielectric constant of the thermosetting resin used is low. As a result, the laminate can further achieve a low dielectric constant.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited in any way by these examples.

Example 1 3E glass fiber ECE225 limited to Japanese Industrial Standards
-110 IZ (22,5Tex) and single yarn diameter 21μ
Using PPS (polyphenylene sulfite) fibers (manufactured by Kijin Corporation, 200/48 type), two glass fiber yarns were woven into each end of the base material in the longitudinal direction, and the remaining warp and weft yarns were woven with PPS fibers. A plain weave type base material with a width of 500 woven fabrics was prepared. (See Figure 1) m2 of this base material
The weight per piece was 70 gr. Epoxy resin alligator on this base material, 2. Impregnated with VE-67N (epoxy resin for FR-4, Hitachi Chemical), heated at 170°
The solvent was removed by drying at a C1 coating speed of 3 m/++in to produce a prepreg. At this time, no base material breakage occurred.

The thickness of the PPS fiber part of this prepreg is approximately 0.17
It was a cabinet. The part of this prepreg that does not contain glass fibers is cut, eight sheets of the resulting prepreg are laminated, and both sides of the laminate are coated with electrolytic copper foil TSTO-35 (one side roughened electrolytic steel foil,
A sheet of Furukawa Circuit Foil (35 μm thick, made by Furukawa Circuit Foil ■) was placed thereon, which was then sandwiched between two end plates and molded under heat and pressure. The heating temperature was 170℃, the heating time was 90 minutes, and the pressure was 4
It was 0 kgf/c■2. The obtained double-sided copper-clad laminate had a thickness of 1.6 m, and was free from voids, scratches, warpage, and twisting. Table 1 shows the main properties of this laminate.

Example 2 Instead of PPS fiber in Example 1, a single yarn diameter of 21μ
m PEEK (polyetheretherketone) fiber (
A plain weave type base material was produced in the same manner as in Example 1 except that 200/4 B type (manufactured by Kijin ■) was used. The weight per l1lz of this base material was 100 gr. This base material was impregnated with polyamino bismaleimide varnish VI-68N (polyamino bismaleimide resin, manufactured by Hitachi Chemical Co., Ltd.), and the solvent was removed by drying at a heating temperature of 170°C and a coating speed of 3 m/s+in to produce a prepreg. did. At this time, no base material breakage occurred. A portion of this prepreg not containing glass fibers was cut and molded under heat and pressure in the same manner as in Example 1 to obtain a laminate having a thickness of 1.611III. However, the heating temperature was 200°C, the heating time was 120 minutes, and the pressure was 40 kgf/cm''. Table 1 shows the main properties of this laminate.

Example 3 Instead of PEEK fiber in Example 2, single yarn diameter 36
A plain weave type base material was prepared in the same manner as in Example 2, except that PEI (polyetherimide) fiber (manufactured by Kijin ■ Co., Ltd., 225/18 type) was used, and polyamino maleimide varnish Vl-68N was applied to this base material. was impregnated to produce prepreg. At this time, no base material breakage occurred. Using this prepreg, a laminate was produced in the same manner as in Example 2. Table 1 shows the main properties of this laminate.

Comparative Example 1 In Example 1, all PP without glass fiber
Solvent drying was carried out in the same manner as in Example 1 except for using a plain weave type base material woven with S fibers. At this time, the base material broke and the prepreg could not be produced.

Comparative Example 2 In Example 2, all PE without glass fiber
Solvent drying was carried out in the same manner as in Example 2, except that a plain weave type base material woven from EK fibers was used. At this time, the base material broke and the prepreg could not be produced.

Comparative Example 3 In Example 3, all PE without glass fiber
Solvent drying was carried out in the same manner as in Example 3, except that a plain weave type base material woven with I fibers was used. At this time, the base material broke and the prepreg could not be produced.

Comparative Example 4 Table 1 shows the main characteristics of an FR-4 grade copper clad laminate MCL-E-67 (manufactured by Hitachi Chemical Co., Ltd.) using conventional glass as a base material.

Table 1 Characteristics of various copper-clad laminates [Effects of the invention] According to the present invention, the base material does not break during the coating process, has a low dielectric constant, has excellent heat resistance, and has good heat resistance for drilling. A method for producing a thermoplastic fiber cloth substrate laminate can be provided, and its industrial value is great.

[Brief explanation of drawings]

Figure 1 shows the glass fiber P used in one embodiment of the present invention.
It is a partially omitted enlarged plan view of a PS fiber mixed fiber base material (handmade type). Explanation of symbols I E glass fiber 2 PPS fiber diagram

Claims (3)

[Claims] 1. Prepreg is produced by coating a thermosetting resin on a base material woven into a cloth using glass fiber for some of the warp threads and heat-resistant thermoplastic fibers with a melting point of 270°C or higher for the remaining warp threads and weft threads. produced, cut the part of this prepreg that does not contain glass fiber to a predetermined size, laminate the required number of cut prepregs, place copper foil on both or one side of the obtained laminate as necessary, A method for producing a heat-resistant thermoplastic fiber cloth base laminate, which comprises heating and pressing. 2. 2. The method for producing a heat-resistant thermoplastic fiber cloth substrate laminate according to claim 1, wherein glass fiber is used for the warp threads at the ends in the longitudinal direction of the substrate. 3. The method for producing a heat-resistant thermoplastic fiber cloth base laminate according to claim 1 or 2, wherein the heat-resistant thermoplastic fiber is any one of polyetheretherketone, polyetherimide, and polyphenylene sulfide.