JPH0144149B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for manufacturing a metal foil-clad laminate that improves the adhesive strength of metal foil to the laminate. In recent years, metal foil-clad laminates have been widely used in the electronics industry. As parts of electronic devices become more densely packaged, there is a trend toward narrower circuit patterns and smaller land areas obtained by processing metal foil-covered laminates, and at the same time, these circuit boards are being assembled using automatic assembly equipment. Since these metal foils are often assembled together, there is a tendency for many defects to occur due to the weak adhesive strength of the metal foil to the laminate. For example, the conductor width of metal foil is 0.2~
When processing circuit boards designed with 0.5 mm in an automatic melting soldering line process, metal foil peeling defects can reach several percent, which is a problem. An object of the present invention is to overcome such a situation and to obtain a metal foil-clad laminate with fewer metal foil peeling defects. In order to improve the adhesive strength of the metal foil to the laminate, the prepreg obtained by impregnating and drying the base material with a thermosetting resin varnish is treated with a silane coupling agent during the laminate manufacturing process. , the prepreg is laminated at least at a position in contact with the metal foil, and is heated and press-molded. Silane coupling agents are organosilicon monomers that have two or more different reactive groups in their molecules, and one of the two reactive groups is a methoxy group, ethoxy group, or silanol group that chemically bonds with the metal foil. Another reactive group is a vinyl group, epoxy group, amino group, etc. that chemically bonds with the thermosetting resin. That is, in the present invention, when prepregs are laminated and heated and pressure-molded, the thermosetting resin mixed with the silane coupling agent in the prepreg melts and flows, and then hardens, and the silane coupling agent bonds with the resin and metal foil. A metal foil-clad laminate with high adhesive strength can be obtained by creating a bridging structure with strong chemical bonds between the two. Note that there is a known method in which a silane coupling agent is added to a thermosetting resin varnish in advance, and a prepreg obtained by impregnating and drying the silane coupling agent into a base material is used, but such a method does not improve adhesive strength. It has been experimentally confirmed that there is no effect on It is also known to treat metal foil with a silane coupling agent, but in this case the molten resin and the silane coupling agent do not mix well. However, in the present invention, since the prepreg is further treated with a silane coupling agent, the silane coupling agent and the molten resin mix well and have the effect of lowering the viscosity of the molten resin.
The resin with a high content of silane coupling agent flows well into the fine irregularities on the surface of the metal foil, increasing the adhesive strength of the metal foil. In the present invention, the method of treating prepreg with a coupling agent involves impregnating a base material with thermosetting resin varnish and applying a silane cup whose pH has been adjusted with acetic acid etc. to the prepreg that comes out of the drying process. A ring agent solution is applied by a spray method, dip method, etc., and then dried at around 100°C for several seconds to several minutes. The appropriate concentration of the silane coupling agent solution is about 1% by weight, and the most effective amount of silane coupling agent solution is 0.3 to 0.5% based on the weight of the prepreg, but there is no particular limit to the range. do not have. Next, the silane coupling agent that can be used in the present invention includes all organosilicon monomers, but when the thermosetting resin is an epoxy resin, gamma glycidoxypropyltrimethoxysilane is preferred, and phenolic resins are preferred. In this case, gamma-aminopropyltriethoxysilane is preferable, and is appropriately selected depending on the type of metal foil used, the structure of the laminate, etc. Furthermore, in the present invention, the prepreg treated with a silane coupling agent does not necessarily need to be used on the entire prepreg, but may be used at least in the position where it contacts the metal foil. Next, examples of the present invention will be described. Example 1 Epoxy resin EPON-1001 (Ciel Chemical) 100
A prepreg was obtained by impregnating a glass cloth with an epoxy resin varnish consisting of 4 parts by weight of dicyandiamide as a hardening agent and 0.5 parts by weight of benzyldimethylamine as an accelerator to a resin content of 40% and drying. The prepreg was sprayed with a 1% aqueous solution of a silane coupling agent gamma glycidoxypropyltrimethoxysilane to a coating amount of 0.3 to 0.5%, and then dried at 100° C. for 1 minute. Seven prepregs treated with the silane coupling agent were laminated, and both sides were coated with
A 35μ thick copper foil was placed at a temperature of 160℃ and a pressure of 60Kg/
cm ² for 30 minutes to obtain a 1.6 mm thick double-sided copper foil-clad laminate (invention product 1). Example 2 The same method as in Example 1 was used, except that a prepreg treated by spraying a 1% aqueous solution of a silane coupling agent to a coating amount of 0.1 to 0.2% was used.
A 1.6 mm double-sided copper foil-clad laminate was obtained (invention product 2). Conventional Example 1 A double-sided copper foil-clad laminate with a thickness of 1.6 mm was obtained in the same manner as in Example 1, but using a prepreg that was not treated with the silane coupling agent of the present invention (Conventional Product 1). Conventional Example 2 0.5% by weight of the same silane coupling agent was added to the same epoxy resin varnish as in Example 1.
This was impregnated into a glass cloth to a resin content of 40% and dried to obtain a prepreg. Using the prepreg, a double-sided copper foil-clad laminate with a thickness of 1.6 mm was obtained by the same molding method as in Example 1 (Conventional Product 2). Next, Table 1 shows the results of measuring the copper foil peel strength according to the JIS method for invented products 1 and 2 and conventional products 1 and 2. Circuit boards with patterns are automatically melted on a soldering line (soldering temperature 250℃, line speed 1m/min)
Table 2 shows the copper foil peeling failure rate when treated in the process.

【table】

[Table] As is clear from Tables 1 and 2, the present invention has a strong metal foil peeling strength, and is fully compatible with the automated line manufacturing process for high-density mounting of parts in recent electronic devices. The industrial value of this method is extremely great as it allows the production of metal foil-clad laminates.

Claims (1)

[Claims] 1. When a predetermined number of prepregs obtained by impregnating and drying a base material with a thermosetting resin varnish are laminated with metal foil on both sides or one side and then heated and press-molded, at least the metal foil and A method for manufacturing a metal foil-clad laminate, characterized in that the contacting surface uses the prepared prepreg further treated with a silane coupling agent. 2. The method for producing a metal foil-clad laminate according to claim 1, wherein the silane coupling agent is attached to the prepreg in an amount of 0.3 to 0.5% based on the weight of the prepreg.