| 摘要 |
PURPOSE:To provide titled powder which exhibits good wettability and adhesive strength and has high reliability by incorporating a specific ratio each of Sn and In into solder powder and consisting the balance of Pb and unavoidable impurities and specifying the content of a radioactive isotope as the impurity. CONSTITUTION:The solder powder of the paste for assembling a semiconductor device contains, by wt%, 1-65% 1 or 2 kinds of Sn and In, contains 1-10% Ag according to need and consists of the balance Pb and unavoidable impurities. The content of the radioactive isotope as the unavoidable impurity is further specified to <50ppb and the count number of the radioactive alpha particles is made <=0.5CPH(count/hour)/cm<2>. The solder powder which is inexpensive, exhibits the good wettability and adhesive strength, obviates the generation of memory errors and has the high reliability is thus obtd. |
