Electrically conductive adhesive sheet, circuit board and electrical connection structure using the same

An electrical connection structure comprising:

• a first circuit board comprising a substrate having a first set of electrically conductive tracks formed thereon,
• a second circuit board comprising a substrate having a second set of electrically conductive tracks formed thereon in confronting relation to said first set of electrically confronting tracks, and
• an electrically conductive adhesive sheet bonding said circuit boards together to provide electrical conntinuity between said first and second sets of electircally conductive tracks, said adhesive sheet containing a uniformed dispersion of electrically conductive metal powder particles electrically insulated from each other by an electrically insulating meltable adhesive material, the powder particles located between the confronting sets of tracks being deformed and flattened while the powder particles in said sheet between said confronting sets of tracks being undeformed and unflattened, the deformed and flattened particles providing area contact between themselves and said confronting sets of tracks, the meltable adhesive having a melting point above the melting point of the metal powder particles and mechanically uniting said two sets of tracks together as a result of solidification from the molten state while under mechanical pressure.