JPS6339424B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to 2-vinyl-4,6-diamino-s-
triazine The present invention relates to a method for producing a copper-clad laminate that is made of an epoxy resin mixed with a curing agent (hereinafter abbreviated as VT) and has excellent heat resistance and copper migration prevention effect. That is, it is based on a solution obtained by dissolving a mixture of a general-purpose epoxy resin, VT, dicyandiamide, and a certain imidazole compound, or a mixture of the remaining three components after removing dicyandiamide from the above four components, in a solvent such as methyl ethyl ketone or methyl cellosolve. After impregnating the material and removing the solvent, copper foil is heat-pressed onto the impregnated base material to create a copper foil that has high heat resistance, high volume resistance at high temperatures, low dielectric constant, and excellent copper migration prevention effect. This invention relates to a method for manufacturing copper-clad laminates. (Prior art) Glass manufactured by heat-pressing copper foil onto a woven glass fiber fabric impregnated with an epoxy resin and a hardening agent.
Epoxy copper-clad laminates have traditionally been used in the industrial equipment field. Recently, the spacing between circuits obtained by etching copper foil has become narrower, the number of components mounted has become smaller and larger, and the number of layers has increased, making the heat resistance and high temperature required for the board more difficult. The electrical properties of copper and the anti-migration properties of copper have become highly advanced. Polyimide resins and maleimide resins are used as resins for copper-clad laminates that require such properties. These resins have excellent heat resistance and electrical properties, but are limited by solvents. For example, an expensive and high boiling point solvent such as N-methylpyrrolidone (meaning that the solvent is difficult to remove) must be used, and a curing temperature of 200° C. or higher is required. On the other hand, epoxy resins such as bisphenol A diglycidyl ether and epoxidized cresol novolak resin, which are used in fields where high heat resistance is not required, can be easily mixed with inexpensive, low-boiling point solvents such as methyl ethyl ketone, methyl cellosolve, and toluene. Even after dissolving and impregnating the base material, the solvent can be easily removed. Further, each of the above-mentioned resins is sufficiently cured at 200°C or lower. However, their glass transition points (which serve as a measure of heat resistance) are lower than those of the aforementioned polyimide and bismaleimide resins. Therefore, it has poor thermal properties. It also has poor electrical properties. (Means for Solving the Problems) In view of the above circumstances, the inventor of the present invention, as a result of intensive research, developed a composition in which VT, a certain imidazole compound, and dicyandiamide were added to a general-purpose epoxy resin, dissolved in methyl ethyl ketone, etc. We have now discovered a method for producing a copper-clad laminate with excellent heat resistance and electrical properties at high temperatures, by impregnating a base material with the solution, removing the solvent, and hot-pressing a copper foil. Epoxy resins suitable for carrying out the present invention may be diglycidyl ether of bisphenol A, epoxidized phenol novolac resins, epoxidized cresol novolak resins, brominated epoxy resins thereof, etc. alone or in combination. The imidazole compound is as shown below. 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole,
2-phenylimidazole, 2-undecylimidazole, 2-heptadecyl imidazole, 2,
4-diamino-6-{2'-methylimidazolyl-
(1)′}-Ethyl-s-triazine. VT is a method of reacting dibiguanide with acrylic acid chloride [J.Am.Chem.Soc., 80, 988,
(1958)], a method for reacting dicyandiimide with β-dimethylaminopropionitrile (French Patent No. 1563255), and 1,2-di{4′,
Method of heating 6'-diamino-s-triazinyl(2)'}-cyclobutane under reduced pressure (Japanese Patent Publication No. 1983-35068)
Manufactured by et al. Example 1 100 parts by weight of Epicote #828 (oiled shell epoxy) was mixed with 2 parts by weight of 2,4-diamino-6-6-
{2-methylimidazolyl(1)}-ethyl-s-triazine When curing with 20 parts by weight of VT, the electrical properties of the obtained cured products were compared. Table 1 shows the results.

【table】

[Table] As mentioned above, when VT is added to a combination of Epicote #828 and a certain imidazole compound, the volume resistivity when heated increases and the dielectric constant decreases. This is an extremely effective property improvement for copper-clad laminates. It is common knowledge in the industry that copper migrates between through-holes or between the front and back surfaces of a copper-clad laminate through the glass fibers of the laminate under high temperature and humidity (so-called migration). Therefore, it is necessary to use an epoxy resin composition that has an effect of preventing copper migration in the laminate. Epoxy resin compositions containing VT are suitable for that purpose. Example 2 A comb-shaped electrode circuit with a conductor width of 0.5 mm and a conductor spacing of 0.3 mm was formed by etching the copper foil of a NEMA standard XPC copper-clad laminate, and 1 weight of 100 parts of Epikote #828 was applied on the circuit. Part of 2,4-diamino-6
-{2′-methylimidazolyl-(1)′}-ethyl-s
- Epoxy resin composition containing triazine and 10 parts by weight of VT, as well as 100 parts by weight of Epikote #828 and 6 parts by weight of 2,4-diamino-6-
{2′-Methylimidazolyl-(1)′}-ethyl-s-
An epoxy resin composition containing triazine and 2 parts by weight of dicyandiamide was screen printed to a film thickness of 20 microns and cured at 150°C for 15 minutes under the conditions of 60°C, 95% RH, and an applied voltage of 30 V DC. After leaving it for 500 hours, we observed the state of discoloration and migration of the copper, and found that the former (composition containing 10 parts by weight of VT) had no abnormalities after 500 hours, while the latter had no abnormality after 100 hours. Discoloration and needle-like growth of copper was observed. As shown in Examples 1 and 2, the epoxy resin composition used in general copper-clad laminates
It can be seen that the addition of VT significantly improves the volume resistivity, dielectric constant, and migration resistance at high temperatures. The appropriate amount of VT to be added is 5 to 50 parts by weight per 100 parts by weight of the epoxy resin. It is thought that the double bond of the terminal vinyl of VT undergoes thermal polymerization and penetrates into the network of the cured epoxy resin, giving a polymer with excellent properties. VT alone is a hard and brittle polymer, but when it coexists with an epoxy resin polymer, it exhibits excellent properties. Therefore, a peroxide that polymerizes the double bond of VT, such as dicumyl peroxide, may be added at the same time. Also, since VT does not dissolve in solvents that dissolve epoxy resins well, such as methyl ethyl ketone and methyl cellosolve, it must be well dispersed in the epoxy resin using a machine such as a three-roll mill before use. In the present invention, base materials such as glass woven cloth of glass fiber, glass nonwoven cloth, laminated mica paper, etc. can be used. Further, in order to make the copper clad laminate flame retardant, a brominated epoxy resin or a halogen compound may be added. Next, a method for manufacturing a copper-clad laminate will be described in Examples. Example 3.4 Each composition shown in Table 2 was dissolved in methyl ethyl ketone and methyl cellosolve to prepare a solution with a solid content of 43.6 wt%.

【table】

[Table] Next, a glass woven fabric treated with aminosilane having a thickness of 0.18 mm was impregnated with the solution of each of the above compositions, and the solvent was removed by air drying. Examples 3 and 4 were heated to 90°C for 3 minutes, and Comparative Example 2 was heated to 90°C for 3 minutes.
Pre-cure at 150℃ for 3 minutes, resin content is 45~
A 50wt% prepreg was produced. Eight sheets of prepreg were stacked, 35 micron copper foils were placed on top and bottom of the prepregs, and heat and pressure curing was performed at 170° C. and 50 to 60 KG/cm ² for 90 minutes. Then further
Curing was carried out at 200°C for 60 minutes. Table 3 shows various properties of the produced copper-clad laminate.

【table】

【table】

Claims (1)

[Scope of Claims] 1. A base material comprising an organic solvent solution of a mixture consisting of a general-purpose epoxy resin, 2-vinyl-4,6-diamino-s-triazine, and at least one compound selected from the following imidazole compound group. 1. A method for manufacturing a copper-clad laminate, which comprises impregnating the base material with a copper foil, overlapping the impregnated base material with a copper foil, and then heat-pressing the same. Imidazole compound group: 2-methylimidazole, 2-ethyl-4-methylimidazole, 2
-Phenylimidazole, 2-phenyl-4-
Methylimidazole, 2-undecylimidazole, 2-heptadecyl imidazole, 2,4
-diamino-6-{2'-methylimidazolyl
(1)′}-Ethyl-s-triazine. 2 Claim 1, characterized in that it contains 5 to 50 parts by weight of 2-vinyl-4,6-diamino-s-triazine and 1 to 5 parts by weight of an imidazole compound per 100 parts by weight of a general-purpose epoxy resin.
A method for producing a copper-clad laminate as described in Section 1. 3 Impregnating a base material with an organic solvent solution of a mixture consisting of a general-purpose epoxy resin, 2-vinyl-4,6-diamino-s-triazine, dicyandiamide, and at least one compound selected from the following imidazole compound group, A method for manufacturing a copper-clad laminate, which comprises superimposing the impregnated base material on a copper foil and then heat-pressing the same. Imidazole compound group: 2-methylimidazole, 2-ethyl-4-methylimidazole, 2
-Phenylimidazole, 2-phenyl-4-
Methylimidazole, 2-undecylimidazole, 2-heptadecyl imidazole, 2,4
-diamino-6-{2'-methylimidazolyl
(1)′}-Ethyl-s-triazine. 4. Contains 5 to 50 parts by weight of 2-vinyl-4,6-diamino-s-triazine, 1 to 20 parts by weight of dicyandiamide, and 0.2 to 5 parts by weight of an imidazole compound per 100 parts by weight of a general-purpose epoxy resin. A method for manufacturing a copper-clad laminate according to claim 3.