METHOD OF MAKING PRINTED WIRING BOARD AND ELECTRICALLY-CONDUCTIVE BINDER

摘要

A thermosetting resin sheet is sandwiched between first and second support bodies so that a first electrically-conductive land on the first support body is opposed to a second electrically-conductive land on the second support body in an opening formed in the sheet. The opening is filled with an electrically-conductive binder. The electrically-conductive binder includes matrix material containing a thermosetting resin and fillers including copper particles dispersed in the matrix material. The copper particles have the surface coated with a tin-bismuth alloy. When heat is applied to the electrically-conductive binder, the tin-bismuth alloy melts. The tin forms an intermetallic compound on the surface of the individual copper particle. The copper-tin alloy layers serve to unit the copper particles together. Electrical connection is established. The bismuth embeds the copper particles. The bismuth is hardened or cured. The matrix material is then hardened or cured.