JPS59166533A - Thermosetting resin laminated board having high dimensional stability - Google Patents

Abstract

PURPOSE:To manufacture a thermosetting resin laminated board having excellent mechanical strength and small dimensional change with temperature and humidity, by using a cellulosic fiber base paper having a specific density and containing a specific amount of glass fiber, as the base of prepreg. CONSTITUTION:The objective laminated board is manufactured by impregnating a thermosetting resin for laminate (e.g. bisphenol-type epoxy resin) in a base consisting of a cellulosic fiber base paper (e.g. linter paper made from linter pulp) having a density of 0.3-0.6g/cm<3> and containing 3-20wt% of glass fiber (preferably E glass for electrical use having the form of opened filament with 6-13mum in diameter and 3-20mm. in length), drying the impregnated resin, and laminating and hot-pressing the obtained prepreg sheets.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laminate, and its object is to provide a laminate that has excellent mechanical strength and exhibits small dimensional changes during temperature and humidity treatments.

Conventionally, glass cloth-based materials, paper-based epoxy resin or phenolic resin laminates, and copper-clad laminates have been used for printed wiring boards for industrial and consumer electronic devices, and insulating substrates for electronic components. .

In recent years, the demand for smaller and lighter electronic devices has led to demands for printed wiring boards to be denser, finer, and multilayered, and there is also a trend toward thinner laminates. However, in the case of paper-based laminates and copper-clad laminates, the XYZ axis directions (horizontal, vertical, and thickness directions) are affected by temperature and humidity treatments such as soldering during processing and component mounting. It lacks dimensional stability and is prone to warping and twisting, and when the plate thickness is made thinner, the mechanical strength decreases and warping and twisting become larger, making it difficult to automate the processing process and final assembly process. There were some problematic drawbacks.

In order to solve these problems, the resins used are modified in various ways, the base paper is treated in advance, or its composition is changed, or inorganic powder is dispersed in the base paper or resin. This is dealt with by using laminated boards made of wood. However, no material has been found that satisfies all of the dimensional stability, mechanical strength, lightness (specific gravity), low-temperature punching workability, cost, etc. of a laminate.

In view of these points, the present inventors have diligently pursued the effect of improving dimensional stability by compounding the base paper base material used.
It has been found that compositing between specific fibers significantly improves the performance.

In the present invention, a base material is impregnated with a thermosetting resin for laminates, and dried silipreg is heated and heated. In the laminate formed by molding the base material, the glass fiber is mixed in an amount of 3 to 20% by weight, and the density is 0.3 to 0-6 Vlct& (D). It is a good thermosetting resin laminate, and optimally (1!) The glass fiber to be made is E glass for electrical use, and the fiber diameter is 6 to 13μ.
It is in the form of a fibrillated filament with a length of 3 to 'lIJwn, and in a single-sided or double-sided copper-clad thermosetting resin laminate made by pasting copper foil on the surface of the laminate, the copper foil This laminate is characterized by having at least one prepreg made of glass fiber-mixed cellulose fiber base paper disposed in the layer directly below it.

That is, it is characterized by using, for example, mixed paper made from kotsutonori/tar pulp and made by uniformly dispersing and defibrating specific glass fibers in the process of making linter base paper for laminate boards. In this case, there is no need for a special binder, and the glass fibers are moderately mixed in the gaps between the base paper fiber micelles, which strengthens the paper and creates a rigid network structure, making it possible to significantly reduce dimensional changes compared to unmixed base paper. I found out that it is possible.

As a result of various studies, for this purpose, it is most preferable to use a mixed paper containing cellulose fibers, such as cellulose fiber pulp called linter paper or kraft paper, in which the glass fiber content is in the range of 3 to 20% by weight. It became clear.

If it is less than 3tI), the effect of improving the dimensional stability of the glass fiber is insufficient, and if it is more than 20'fi, the reinforcing effect on mechanical strength is observed, but the dimensional stability tends to warp and decrease. That is, the heating yield of the laminate becomes almost constant at 20 inches or more, but the amount of thermal expansion in the thickness direction (two directions) becomes large, which is not preferable. This is thought to be because the glass fibers in the mixed paper have been fully decomposed and mixed, so the internal stress during lamination molding becomes large, especially in the thickness direction.

On the other hand, when the amount of lath fibers increases to 20 inches or more, the rigidity, hardness, and specific gravity become poor, and the punching workability of the laminate also decreases.

Next, the selection of glass fibers to be mixed is an important factor in terms of electric properties, dimensional stability, strength, processability, productivity of base paper, and economic efficiency, as well as the mixing ratio, and from the viewpoint of mixing with cellulose fibers. E glass, fiber diameter 6-13μm, vR
Fibers with a fiber length of 3 to 20 w+m are suitable.

It is not necessarily necessary to use one treated with a silane coupling agent. This objective can be achieved by adding a silane coupling agent when impregnating the resin face.

The density of a base paper is an important factor for impregnation with resin varnish, and by mixing glass fiber, a low density base paper with good impregnability can be obtained, and it is 0.3 to 0.6.
A range of f/d is suitable.

Of course, an inorganic substance such as antimono trioxide can be added to impart flame resistance to this mixed paper. Furthermore, the most important thing is that when manufacturing this mixed paper, the glass fiber content in the range of 3 to 20% by weight can be produced using a conventional base paper machine without any special equipment modification. This is a major driving force for promoting the practical application of the present invention from an economic standpoint.

The thermosetting resin used in the present invention is, for example, a resin made by reacting phenols with formaldehyde, and if necessary, a phenol resin modified with alkylphenols, drying oil, xylene resin, etc. during the reaction, or a bisphenol-based epoxy resin. Epoxy resins made of a mixture of one or more mixed resins such as resins, novolak epoxy resins, and alicyclic epoxy resins, and amine curing agents or other curing agents. It is also possible to treat the base material with a mono- or dinuclear low-molecular weight phenolic resin or methylolated melamine resin, which has good affinity for the base material, before impregnating it with the resin varnish.

Impregnation using the above-mentioned base paper and these resins according to a conventional method.
The laminate obtained by drying and heating lamination molding has excellent mechanical strength, and there is little dimensional change, warping, or twisting due to temperature and humidity treatment, and even thin plates have the necessary strength. A product with good low-temperature punching workability was also obtained. In addition, the heat shrinkage rate not only in the XY direction but also in two directions is extremely small, so conventional paper-based laminates have been manufactured using double-sided copper-clad laminates or laminates as starting materials, which had problems with uneven through-hole connections. It can also be applied to double-sided circuit boards, etc.
A paper-based through-hole circuit board with high g-compatibility was obtained.

One-sided or double-sided copper-clad laminates can be obtained by overlapping copper foils during lamination molding, but by placing at least one silicone preg made of glass fiber mixed paper in the layer directly below the copper foil, the copper foil and substrate can be obtained. Warpage and twisting caused by temperature and humidity treatment during the processing process caused by the difference in thermal expansion coefficient between the board and heat shrinkage of the board, especially during the soldering process where components are mounted and connected on a printed wiring board. It has a very large suppressing effect. Of course, a copper-clad laminate formed using mixed paper for all layers has good properties, but this is accompanied by a decrease in low-temperature punching properties, making it particularly suitable for thin plates.

As described above, by implementing the method of the present invention, there is less dimensional change due to temperature and humidity treatment, less warpage, less twisting,
In addition, a laminate or copper-clad laminate with high mechanical strength can be obtained, and the thickness of the plate can therefore be reduced, which is preferable from the viewpoint of resource saving.

The present invention will be specifically explained below using examples.

Example 1 Linter base paper with a different blending ratio of glass fibers was impregnated with a phenolic resin varnish modified with tung oil and a silane coupling agent, and then laminated and molded to obtain a grisograph with a resin content of 5.
A laminate with a thickness of 0% and a thickness of 1.6 mm was obtained.

The dimensional change rate and bending strength of these laminates due to heating and humidity treatment were as shown in Table 1.

9- (Note) Heat shrinkage rate: Rate of change with respect to initial dimension after constant rate heating and cooling treatment at 10°C/min from room temperature to 250°C.

Amount of thermal expansion: The rate of change with respect to the initial dimension when the temperature is raised from room temperature to 250°C.

Humidity swelling rate: Rate of change with respect to initial size after O-96/40/90 treatment.

Bending strength: J Engineering S- -6911K, 1: Le, Example 2 Using linter base paper with a different glass fiber mixing ratio, prepreg was made by impregnating a varnish containing a phenol resin modified with tung oil and a Silanka YF ringing agent. After that, lamination molding was performed to obtain laminates of various thicknesses with a resin content of 45 cm.

The results of comparing the bending strength, punchability and anti-chip properties of these laminates are shown in Table 2.

(Note) Bending strength: Based on J Engineering S-6911.

Punching property: According to ASTM-D-617.

(Punching temperature: room temperature) Warpage characteristics: Total of 220 samples of 420 x 330 mm
℃ for 10 minutes, and after cooling, it was placed flat on a surface plate and the maximum lifting amount (=) was measured.

Example 3 Using kraft base paper with a glass fiber mixing ratio of 10%, prepreg was obtained by impregnating it with a varnish containing a phenol resin or epoxy resin mixed with a silane coupling agent, and then laminating and molding it with copper foil. Plate thickness of 40 inches 1.
A 2 mm copper-clad laminate was obtained.

The characteristics of the board thickness 1 obtained using conventional kraft base paper
．． The results shown in Table 3 were obtained by comparing with the board No. 6.

-14-Example 4 Using linter base paper with a glass fiber mixing ratio of 10%, impregnating it with a varnish containing an epoxy resin and a silane coupling agent to obtain a prepreg, followed by layer molding with # and a resin content of 50 chips. A laminate with a thickness of 1.6 rtan was obtained. Furthermore, an additive process contact M agent made of nitrile rubber and phenol resin was coated on the downward surface and dried and cured to obtain a substrate for additive process. Using this, we created a copper through-hole plating circuit board using a semi-additive process, and conducted a through-hole connection reliability test. The results are shown in Table 4.

15- Table 4 (Note) The cycle test is the rate of change in conduction resistance (expressed as porridge).

Patent applicant: Sumitomo Bakelite Co., Ltd. 16-

Claims (4)

[Claims] (1) In a laminate formed by heating and laminating Glypreg, which has been impregnated with a thermosetting resin for laminates and dried, the density sail 3 is mixed with glass fiber in an amount of 3 to 3% by weight as the base material. A thermosetting resin laminate with good dimensional stability, characterized by using cellulose fiber base paper of 0.6 t/l, td. (2) In single-sided or double-sided copper-clad laminates made by heating and laminating Glyshireg, which is impregnated with a thermosetting resin for laminates and dried, the amount of glass fiber is added to the layer directly below the copper foil as the base material. 3-20% by weight mixed paper density 0.3-0.6?
At least one prepreg using shoulder cellulose fiber base paper
& [A thermosetting resin laminate with good dimensional stability, characterized in that the top is arranged and used. (3) The glass fiber to be mixed is E glass for electrical use, and the fiber diameter is 6 to I3/1 m and the length is 3 to 2 Dtt.
A thermosetting resin laminate having good dimensional stability as claimed in claim (1) or (2) m = in the form of fibrillated filaments of rm. (4) Claim m (1) or (2) wherein the cellulose fiber base paper is linter paper made from linter parno.
) A thermosetting resin laminate with good dimensions and dimensions listed in Yasuya.