| 摘要 |
<p>The invention relates to a nonresinous solder paste made of a metal powder, especially soft solder, and a gel which leaves no residues on the metal surface when the metal powder is melted down. The inventive gel is based on a mixture of carboxylic acid/s, amine/s, and solvent/s, said mixture being stable during storage. Major uses include applying soft solder pastes to power modules, die attach, chip on board, system in package (SiP), wafer bumping, particularly under-bump metallization (UBM) and surface-mounted technology (SMT), especially lacquered circuits. Using nonresinous soft solder pastes makes it possible to dispense with the need to perform a cleaning process before applying a protective lacquer after soldering an electrical connection while the formation of pores in solder bumps applied to UBMs is reduced to less than 20 percent by volume.</p> |
