| 摘要 |
<P>PROBLEM TO BE SOLVED: To form a desired and uniform thickness without inclination in a solder junction layer of a semiconductor chip and the other constituent member or a solder junction layer of other constituent members, and to suppress over a long term the growth of an undesirable alloy layer in each of the solder junction layers. <P>SOLUTION: An Ni film is formed on the solder junction surface of each of a semiconductor chip 1, a lead frame 21, an insulating substrate 3, and a heatsink 6. Cream solder is printed on the heatsink 6 on which a filler 31 containing Cu is put. On the filler, the insulating substrate 3 is put on which the cream solder is printed, on which the filler 31 is put. Likewise, the semiconductor chip 1 and the lead frame 21 are put. When the cream solder is melted, and the filler 31 falls to the solder layer and is hardened, the solder junction layers 5, 2, 22 and 23 each having a desired and uniform thickness are yielded. On a junction interface, a Cu-Ni-Sn alloy is formed to suppress the growth of a hard and fragile alloy layer. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
