Abstract
Nowadays, gold is very often used in electric circuits. Most of the resins can, however, hardly adhere to gold. This is a serious problem for applying the resins to electric circuits. The fact is well known that sulfur can bond to gold easily. Then it is considered that the adhesion of a resin to gold may be improved if sulfur is introduced to the resin to form the bond between sulfur and gold. We synthesized certain phenol derivatives containing thiol or disulfide groups, and added them to an epoxy resin which was used in most of the electric circuits. As a result of measuring their effect on the adhesion property, the adhesion strength was decreased when the phenol derivatives contained thiol groups. The reason was considered to be as follows : the thiol groups had reacted with epoxy groups for partially hindering the polymerization of the epoxy resin, thus resulting in decreasing the strength of the resin itself. Also we got the results by quantum chemistry calculation that the S-S bond of the disulfide group was dissociated and the Au-S bond was formed when the dissociated sulfur came near to gold. In conclusion the adhesion property was measured on the epoxy resin, to which a synthesized phenol derivative containing disulfide was added by 2wt%. The result showed that the adhesion strength and energy were increased by 12%, and 24%, respectively.
