JPH0525195B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for manufacturing a printed wiring board substrate used for various industrial purposes such as industrial equipment and electronic equipment, and more specifically, to a method for manufacturing a printed wiring board substrate having excellent moisture resistance and soldering heat resistance. The present invention relates to a method for easily manufacturing a substrate. (Prior art) Conventionally, printed circuit boards used for various industrial purposes are made by impregnating paper, glass cloth, etc. with thermosetting resin such as epoxy resin, phenolic resin, or polyester resin.
After drying, a required number of sheets were laminated, and a printed circuit board was obtained by layering copper foil and forming an electric circuit using the laminated board as a substrate by etching or the like. However, this method requires long manufacturing steps such as impregnation, drying, lamination molding, and cutting, and has low production efficiency.
Moreover, moisture absorption from between the layers of the printed circuit board is large.
It also had the disadvantage of poor soldering heat resistance. (Problems to be Solved by the Invention) As a result of intensive studies in order to solve the above-mentioned drawbacks, the present inventors have determined that ring-opening polymerization and molding of norbornene unit-containing monomers are simultaneously performed by a reaction injection molding method. In particular, the present inventors have discovered that a printed circuit board with excellent moisture resistance and soldering heat resistance can be easily manufactured, and have completed the present invention. (Means for Solving the Problems) According to the present invention, there is provided a method for producing a substrate for a printed wiring board in which ring-opening polymerization and molding of a norbornene unit-containing monomer are simultaneously carried out by a reaction injection molding method using a metathesis catalyst. provided. The norbornene unit-containing monomer used in the present invention is represented by general formula (1) or (2).

【formula】

[Formula] (In the formula, R ₁ to _{R 4} represent hydrogen or a substituent, and R ₁ and
R ₂ , R ₃ and R ₄ may form a saturated or unsaturated ring) monomers. Specifically, 2-norbornene, 5-methyl-2
-norbornene, 5,6-dimethyl-2-norbornene, 5-ethyl-2-norbornene, dicyclopentadiene, dihydrodicyclopentadiene, methyltetracyclododecene, and mixtures thereof. Also, one of these monomers
Mono- and dicycloolefins such as cyclobutene, cyclopentene, cyclooctene, and cyclododecene, which can be ring-opening copolymerized with one or more species, can be used in combination. These monomers are converted into polymers by known ring-opening polymerization, and known metathesis polymerization catalysts are used as catalysts for ring-opening polymerization. - A catalyst system comprising a tungsten-containing compound such as tungsten hexachloride and tungsten oxytetrachloride and an alkyl aluminum halide such as diethylaluminum chloride and ethylaluminum dichloride disclosed in Publication No. 129013;
A transition metal compound such as a catalyst system consisting of an alkyl aluminum halide and an organic ammonium molybdate such as tridodecyl ammonium molybdate or tungstate, or a tungstate as disclosed in JP-A-58-127728. and a cocatalyst such as an organometallic compound or a Lewis acid. In the present invention, the desired printed wiring board is manufactured by using a reaction injection molding method (so-called RIM method) in which ring-opening polymerization and molding can be performed simultaneously. When using the reaction injection molding method, the above-mentioned two-component catalyst is separately mixed with the norbornene unit-containing monomer and used as a two-part reaction solution. For example, the amount of molybdenum- or tungsten-containing catalyst used is usually in the range of 0.01 to 50 mmol per mole of total monomer as molybdenum or tungsten. The amount of the alkylaluminium halide catalyst used is usually in the range of 200:1 to 1:10 in terms of molar ratio of aluminum to molybdenum or tungsten. The reaction injection molding (RIM) method used in the present invention is known as a method for producing polyurethane molded products from polyol and diisocyanate. The product is characterized by the use of a reaction liquid, which allows the target substance to be injected into the mold at a low pressure of only 10 kg/cm ² or less, and which rapidly polymerizes within the mold to produce the desired printed wiring board substrate molded product. It is a process of manufacturing. The temperature of the mold is usually in the range of 40 to 150°C, and in order to simplify the process after molding, it is extremely effective to prepare a mold in advance with through holes for the molded product. Furthermore, in the present invention, plasticizers, impact-resistant agents, fillers, flame retardants, antioxidants, and the like can be mixed into the reaction liquid as necessary. A wiring screen is provided on the thus obtained printed wiring board substrate by adhesive or other method, and then treated with copper or other resin plating chemicals to form a conductive layer, and then copper plating is applied. , the printed circuit board is completed by removing the screen. Further, the method for forming the electric circuit is not limited to this, and a vacuum evaporation method using a mask, a metallicon method using thermal spraying of metal powder, etc. can be used. (Effects of the Invention) Thus, according to the present invention, a method for manufacturing a printed wiring board substrate having superior moisture resistance and soldering heat resistance compared to the prior art is provided. (Example) The present invention will be described in more detail with reference to Examples below. Note that parts and percentages in Examples and Comparative Examples are based on weight unless otherwise specified. Example 1 Desired amounts of dicyclopentadiene were placed in two containers, and in one container, diethylaluminum chloride was adjusted to a concentration of 0.048 mol per mol of the monomer. Similarly in the other container
WCl ₆ was added to a concentration of 0.007 molar. The above-mentioned two-part reaction solution prepared in this way was mixed into 1:
After mixing at a ratio of 1:1 and directly injecting into a mold heated to 50°C and carrying out a polymerization reaction for 2 minutes, a molded plate of 10 cm square and 1 mm thick with through holes was obtained. Next, 50 parts of phenolic resin, 50 parts of acrylonitrile-butadiene copolymer, 1 part of palladium chloride,
Thick adhesive consisting of 250 parts of butyl cellosolve
The coating was applied to a thickness of 0.05 mm, and after heating, the required areas were printed with a plating resist and electroless plated to obtain a printed circuit board. The thus obtained printed circuit board was tested for water resistance and soldering heat resistance. The results are shown in Table 1. Example 2 A printed circuit board was obtained in exactly the same manner as in Example 1 except that dicyclopentadiene was replaced with methyltetracyclododecene, and was subjected to water resistance and soldering heat resistance tests. The results are shown in Table 1. Example 3 A printed circuit board was obtained in the same manner as in Example 1, except that dicyclopentadiene was replaced with a mixture of dicyclopentadiene/methyltetracyclododecene (50/50). The test results are shown in Table 1. Comparative example Bisphenol A type epoxy resin (Epicote
1001 manufactured by Ciel) 100 parts, dicyandiamide 4 parts,
Impregnate a glass cloth with a varnish consisting of 0.2 parts of benzyldimethylamine and 65 parts of dimethylformamide, add the required number of dried prepregs and the top layer.
An epoxy resin copper-clad laminate having a thickness of 1 mm was prepared by stacking 0.035 mm thick copper foils and hot pressing them, and then the laminate was cut into 10 cm squares. Next, an acid-resistant coating was made to define the required circuit pattern, and the board was immersed in an acid corrosive solution to remove unnecessary copper foil to obtain a printed circuit board. Table 1 shows the results of testing the water resistance and soldering heat resistance of the printed circuit board thus obtained.

【table】

Claims (1)

[Claims] 1. A method for producing a substrate for a printed wiring board, characterized in that ring-opening polymerization and molding of a norbornene unit-containing monomer are simultaneously performed by a reaction injection molding method using a metathesis polymerization catalyst.