JPH0584866A - Production of metal foil clad laminated sheet - Google Patents

Abstract

PURPOSE:To provide a metal foil clad laminated sheet well-balanced between the peel strength and tracking resistance of a metal foil. CONSTITUTION:An adhesive composition composed of a polyvinyl butyral resin and an amino resin is applied to that surface of a metal foil which has been pretreated with a silane coupling agent, and it is dried to produce the adhesive coated metal foil. A prepreg obtained by impregnating a fiber base material with a resin is laminated to said metal foil, and this laminate is subjected to hot press molding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a metal foil-clad laminate having excellent tracking resistance.

[0002]

2. Description of the Related Art Smaller and more sophisticated consumer electronic devices have been developed,
The printed wiring boards used for it tend to become more dense. Along with this, metal foil clad laminates such as copper clad laminates used for printed wiring boards are required to be capable of high-density mounting. Therefore, there is a strong demand for the peeling strength of the thinned metal conductor and the improvement of the solder heat resistance during mounting. In addition, tracking resistance has come to be required for a device to which a high voltage is applied, such as a television, from the viewpoint of ensuring safety.
Tracking is a phenomenon in which a carbonized conductive path is formed in a portion on the surface of an insulator where there is a potential difference. Conventionally, an adhesive has been used in which a polyvinyl butyral resin is blended with a phenol resin, which is excellent in solder heat resistance and metal foil peeling strength.

[0003]

However, although an adhesive obtained by blending a polyvinyl butyle resin with a phenol resin has excellent soldering heat resistance, etc., the phenol resin is easily carbonized, so that the resin easily conducts and the tracking resistance is improved. It was inferior in sex. Therefore, in order to improve the tracking resistance of the adhesive, it is proposed in JP-A-63-154777, etc. to use a melamine resin which is hard to carbonize as a material replacing the phenol resin. When the melamine resin was used, the tracking resistance was improved as compared with the case where the phenol resin was used, but there was a problem with the adhesive strength of the metal foil.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a metal foil-clad laminate having a balance between the peeling strength of the metal foil and the tracking resistance.

[0005]

According to the present invention, such an object is to coat and dry an adhesive composition comprising a polyvinyl butyral resin and an amino resin on the treated surface of a metal foil, one side of which is previously treated with a silane coupling agent. This is accomplished by producing a metal foil with an adhesive by laminating a prepreg obtained by impregnating a resin on a fiber base material and thermoforming the metal foil.

The present invention will be described in detail below. Examples of the silane coupling agent used in the present invention include amino silanes, epoxy silanes, vinyl silanes, and mercapto silanes. These silane coupling agents are applied to the metal foil and dried by any method. The coating amount is preferably 0.1 to 6.0 g / m ² .

The polyvinyl butyral resin used in the present invention is not particularly limited as long as it is generally used for adhesives, but as a specific example, S-REC BX-1 (average degree of polymerization 1700, Butyralization degree 65
mol%), BX-2 (same 1700, 65 mol%), BX
-55 (1700, 70 mol%) (manufactured by Sekisui Chemical Co., Ltd., trade name), electrified butyral 4000 (1)
000, 75%), 5000-A (2000, 80 wt.
%), 6000-C (2400, 80% by weight) (trade name, manufactured by Denki Kagaku Kogyo Co., Ltd.) and the like. These resins may be used alone or in combination of two or more.

The amino resin used in the present invention includes:
Examples thereof include melamine resins, benzoguanamine resins, and resins obtained by alkylating these resins, and alkyletherified melamine resins are particularly preferable. Specifically, MS-1
1, MS-001, MW-30, MX-705 (manufactured by Sanwa Chemical Co., Ltd., trade name, methyl etherified melamine resin), Melan 220, Melan 245, Melan 280.
(Hitachi Chemical Co., Ltd., trade name, butyl etherified melamine resin), MX-408 (Sanwa Chemical Co., Ltd., trade name, mixed etherified melamine resin) and the like. These melamine resins may be used alone or in combination of two or more.

The mixing ratio of each of the above components is not particularly limited, but 5 to 100 parts by weight of an amino resin is added to 100 parts by weight of polyvinyl butyral to form an adhesive. An amino resin curing agent may be further added to this adhesive, and examples thereof include carboxylic acids such as p-toluenesulfonic acid and benzoic acid, dicarboxylic acids such as oxalic acid, itaconic acid and adipic acid, or imidodisulphone. Acid, ammonium salicylate, nitrosulfonic acid, etc., and the addition amount is 0.1 to 3 based on the amino resin.
It is in the range of% by weight. Incidentally, with respect to the adhesive composition,
Fillers and other additives can be added within the range not impairing the object of the present invention.

The adhesive of the present invention can be obtained by adding an organic solvent to the above-mentioned compounded material, if necessary, and mixing them. The organic solvent is not particularly limited as long as it can dissolve the above materials, but is not limited to methanol, ethanol, isopropyl alcohol, n-butanol, acetone, methyl ethyl ketone, cyclohexanone, toluene, xylene, methyl cellosolve, ethyl cellosolve, cellosolve. Specific examples thereof include acetate.

The adhesive produced as described above is applied to the silane coupling treated surface of the metal foil to obtain an adhesive-attached metal foil. Examples of the metal foil include, but are not limited to, copper foil and aluminum foil, and the coating method may be kiss coating, roll coating, spin coating, or the like, but is not particularly limited.

A metal foil-clad laminate is prepared by stacking a plurality of paper-based or glass-based prepregs impregnated with a thermosetting resin such as a phenolic resin on the above-mentioned metal foil with an adhesive and heat-pressing them. Get the board. The heat and pressure molding conditions are not particularly limited, but it is preferable to mold at 150 to 180 ° C. for 60 to 120 minutes at a pressure of 5 to 20 Mpa.

[0013]

EXAMPLES The present invention will now be described in detail based on examples, but the present invention is not limited thereto. Examples 1 and 2 and Comparative Examples 1 and 2 The resin formulations shown in Table 1 were uniformly dissolved in a mixed solvent of methanol-methyl ethyl ketone so that the resin content was 30%, and this adhesive was coated with a roll coater to a thickness of 35 μm. The copper foil was applied on a copper foil and dried and cured to obtain an adhesive-coated copper foil having an adhesive thickness of 40 μm. Eight phenol resin-impregnated base materials were laminated on the adhesive side of this copper foil to form a laminated body, which was sandwiched between stainless steel end plates and 1
A copper clad laminate was obtained by heat and pressure molding at 60 ° C. and 10 MPa for 60 minutes. The characteristics of this copper clad laminate are shown in Table 1. In Table 1, solder heat resistance and copper foil peeling strength are measured in J
According to IS C6481, the tracking resistance was measured by an IEC method at an applied voltage of 600V. The parenthesized numbers in the table indicate parts by weight of the formulation.

As is clear from Table 1, in all of the examples, the tracking resistance is improved as compared with the comparative example without deteriorating the characteristics such as solder heat resistance and peeling strength.

[0015]

[Table 1]

[0016]

INDUSTRIAL APPLICABILITY The adhesive composition of the present invention has excellent tracking resistance and does not deteriorate other properties, and is useful as an adhesive for metal foil-clad laminates. The industrial value is great.

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Claims (1)

[Claims] 1. A metal foil with an adhesive is produced by applying an adhesive composition comprising a polyvinyl butyral resin and an amino resin on the treated surface of a metal foil having one surface previously treated with a silane coupling agent, and manufacturing the metal foil with the adhesive. A method for producing a metal foil-clad laminate, which comprises laminating a prepreg impregnated with a resin on a fiber base material and thermoforming.