Patent ID: 6197222
Filing Date: 2001-03-06
Classification: H01B,H01L,H05K

Abstract:
A process of bonding an integrated chip to a circuit board comprising disposing an electrically conductive paste on pads of said chip, said circuit board or both; aligning said pads of said chip and said board, and heating the aligned chip and circuit board to a temperature above the glass transition point of said polymer, wherein said electrically conductive paste comprising a thermoplastic polymer selected from the group consisting of a poly(imide urea), a poly(ether siloxane), a poly(styrene butadiene), a poly(styrene isoprene), a poly(acrylonitrile butadiene), a poly(ethylene vinyl acetate) and a polyurethane, an oxide-free metal powder having a melting point of at least 200.degree. C., wherein said oxide-free powder is an oxide-free elemental metal or an alloy of at least two oxide-free elemental metals, and an organic solvent system which comprises at least one polar organic solvent selected from the group consisting of an ester, an ether, an amide, a lactone, and a sulfone, and an organic non-polar solvent, with the proviso that the paste does not contain a flux agent wherein the paste has a non-Newtonian viscosity in the range of from about 3000-5000 Poise.