JPH0826167B2 - Phenolic resin copper clad laminate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a phenol resin copper clad laminate excellent in moisture resistance and well balanced with other properties.

(Prior Art) In recent years, the development of consumer electronic devices has been remarkable, and in this field as well, aiming at downsizing, weight reduction, and high performance / multifunction, high density wiring of printed wiring boards, high density component mounting, or , Parts self-insertion, etc. are progressing rapidly. For this reason, paper-based phenolic resin printed circuit boards, which are widely used in this field, are also required to have high electrical characteristics, high dimensional stability, and excellent processability. Especially, low-temperature punching processability and high moisture resistance load characteristics are essential. Has become a condition. Regarding low-temperature punching workability, it is necessary to reduce the dimensional variation due to heat shrinkage of the printed circuit board as much as possible, but as the high-density mounting progresses as described above, for example, an IC pitch of 1.78 mm is included. The dense pores must also be punched out at low temperature. Therefore, it is necessary to highly plasticize the resin forming the substrate, and various plasticizing methods have been used.

The main cause of the variation in the characteristics of the paper-based phenolic resin printed circuit board is heat until the punching process, but the maximum factor after that is humidity. That is, the dimension of the substrate expands due to the absorption of moisture in the substrate, and the electrical characteristics are significantly deteriorated. Since the laminated board is a composite material of paper base material and phenolic resin, how to treat the paper base material to reduce the hydrophilic groups of the paper base material or how to impregnate the phenolic resin to absorb moisture of the paper base material Decreasing the amount is a major problem in improving the moisture resistance of the laminate. And this problem is especially remarkable in a highly plasticized resin system. In order to solve this problem, various pretreatment methods and physical impregnation methods for paper base materials have been studied. As a pretreatment method, many pretreatment agents, for example, water-soluble phenolic resin, water-soluble epoxy resin, melamine resin, sizing agents for paper bases such as acrylamide compounds have been studied, but moisture resistance and other There is nothing that is well-balanced with the characteristics of the laminated plate of No. 1, and it was not sufficiently satisfactory even in other methods.

(Problems to be Solved by the Invention) The present invention has been made in order to solve the above problems, and is excellent in moisture resistance without impairing the mechanical strength and punching workability of a laminate. It is intended to provide a phenolic resin copper clad laminate that is balanced with other properties.

[Structure of the Invention] (Means for Solving Problems) As a result of earnest studies to achieve the above object, the present inventor achieved the above object by treating a paper base material with a silane compound in advance. The present invention has been completed and the present invention has been completed.

That is, the present invention is a phenol resin formed by superposing a prepreg obtained by coating and impregnating a phenol resin on a paper base material that does not mix any of inorganic fillers and inorganic fibers, and copper foil and heat and pressurize them integrally. In the copper-clad laminate, the paper base material has been previously impregnated with a silane-based compound, which is a phenol resin copper-clad laminate.
The silane-based compound adheres to the paper substrate in an amount of 1 to 10% by weight.

Examples of the paper substrate used in the present invention include cotton linter paper, kraft paper, and mixed papers thereof, and these are used alone or in combination of two or more.

Examples of the silane-based compound used in the present invention include aminosilane and epoxysilane, and specific compounds include, for example, γ-aminopropyltrimethoxysilane, N-β-aminoethyl-γ-aminopropyltrimethoxysilane, and the like. Examples include β-3,4-epoxycyclohexylethyltrimethoxysilane and γ-glycidoxypropyltrimethoxysilane, which may be used alone or in admixture of two or more. The silane-based compound is preferably attached at a rate of 1 to 10% by weight based on the absolute dry weight of the paper substrate. If the proportion is less than 1% by weight, there is no effect on the moisture resistance, and if it exceeds 10% by weight, there is no further effect, and the cost is rather high, which is not preferable.

As the phenol resin used in the present invention, a phenol resin generally used for laminates can be widely used and is not particularly limited. The copper foil used in the present invention may be a commonly used one regardless of rolled copper foil or electrolytic copper foil and is not particularly limited.

As a method for producing a copper-clad laminate, a prepreg and a copper foil are laminated by a conventional method, and heating and pressure lamination are integrated to form a laminate, and the production method is not particularly limited. The phenol resin copper clad laminate thus obtained is widely used in consumer electronic devices and others.

(Function) The phenol resin copper clad laminate of the present invention can obtain excellent moisture resistance by pretreating the paper base material with the silane compound. It hydrolyzes a silane-based compound as an aqueous solution to produce silanol as shown in the following formula, and ≡SiOR → ≡SiOH impregnate this into a paper base material to produce a polymer by dehydration condensation, and an amino group which is an end group. It is possible to obtain a well-balanced phenol resin copper-clad laminate that exhibits excellent moisture resistance by the reaction of the base or epoxy group with the hydroxyl group in the paper base material and does not impair other properties.

(Examples) Next, the present invention will be specifically described by way of examples, but the present invention is not limited to the examples.

Preparation of varnish 12.9 kg of phenol, 10.0 kg of tung oil and 0.027 kg of paratoluene sulfonic acid are charged in a reaction vessel and reacted at 100 ° C. for 1 hour, and neutralized to pH = 7 with monomethylamine.
Next, after adding 15.6 kg of 37% formalin and reacting at 100 ° C. for 2 hours, dehydration under reduced pressure and diluting with a mixed solvent of toluene: methanol = 1: 1, resin solid content 55%, viscosity 2.0 poise (25
A varnish having a gelation time of 3 minutes (150 ° C.) was prepared.

Example A kraft paper having a thickness of 10 mils was treated with an aqueous solution of 0.5% by weight of γ-aminopropyltrimethoxysilane to make it adhere to the kraft paper at 4% by weight and dried at 100 ° C. This kraft paper was coated and impregnated with the above varnish and dried to prepare a prepreg (A) having a resin adhesion amount of 50% by weight and a range flow of 8%.

Comparative Example 1 Kraft paper having a thickness of 10 mils was coated and impregnated with the above varnish to prepare a prepreg (B) having a resin adhesion amount of 50% by weight and a range flow of 8%.

Comparative Example 2 A kraft paper having a thickness of 10 mils was pretreated with a methylol melamine resin (resin adhesion amount 5% by weight), and then the above varnish was applied and impregnated and dried to give a resin adhesion amount 50% by weight and range flow 8%. I made a prepreg (C).

Eight prepregs prepared in Examples and Comparative Examples 1 and 2 and a copper foil with an adhesive having a thickness of 35 μm were superposed on each other, and the temperature was set to 170.
The single-sided copper-clad laminate with a thickness of 1.6 mm was manufactured by heating and press-molding for 75 minutes under conditions of ℃ and pressure of 100 kg / cm ² .
Tests for moisture resistance, mechanical strength, punching workability, etc. were performed on these laminated plates, and the results are shown in Table 1.
The present invention is excellent in moisture resistance and mechanical strength, has the same other characteristics as other characteristics and is well balanced, and the remarkable effect of the present invention was confirmed.

As shown in Fig. 1, the mechanical strength test is 100 m long.
Cut out a test piece 1 of m and a width of 15 mm, and make two holes of 2.6φ at 50 mm intervals in the center of the test piece. Insert the W-shaped 2.6φ iron rod 3 into the hole 2 of the test piece 1 as shown in FIG.
A load was applied at the pressure terminal 5 at a speed of m / min to determine the mechanical strength by the product of the load and the displacement until failure.

Local stress bending strength (kg ・ mm) = load to failure (kg) x displacement to failure (mm) [Effects of the Invention] As is clear from the above description and Table 1, the phenolic resin copper-clad laminate of the present invention has excellent moisture resistance, good mechanical strength, punching workability, and other characteristics. It is well-balanced and suitable for consumer electronic devices.

[Brief description of drawings]

FIG. 1 is a plan view of a test piece for testing the mechanical strength of the phenol resin copper clad laminate of the present invention, and FIG. 2 is a conceptual sectional view of an apparatus for testing the mechanical strength of the test piece of FIG. . 1 ... Test piece, 3 ... W-shaped iron bar, 4 ... Container.

Claims (2)

[Claims] 1. A phenolic resin copper obtained by stacking a prepreg obtained by coating and impregnating a phenolic resin on a paper base material containing neither an inorganic filler nor an inorganic fiber, and a copper foil, and integrally molding them by heating and pressing. In the stretched laminate, the paper base material has been previously impregnated with a silane-based compound, and the phenolic resin copper-clad laminate is characterized. 2. A phenol resin copper clad laminate according to claim 1, wherein the silane compound is attached to the paper substrate in an amount of 1 to 10% by weight.