Patent ID: 7767032
Filing Date: 2010-08-03
Classification: B23K

Abstract:
1. Solder paste for die-attachment of semiconductor devices comprising a solder powder dispersed in a flux, the flux comprising a homogeneous mixture of a solvent system, at least one thixotropic agent, at least one activator, and a rosin, wherein the solvent system comprises one or more glycol ethers, and one or more alcohols, and a highly viscous solvent and/or solid solvent at room temperature and the concentration of the solvent system amounts to 55 to 75 wt.-% and the concentration of the rosin amounts to 10 to 25 wt.-%, each relative to the total weight of the flux and wherein the highly viscous solvent and/or solid solvent are selected from the group consisting of trimethylopropane, 1,2-octanediol, 1,8-octanediol, isobornyl cyclohexanol or a combination thereof.