| 摘要 |
PURPOSE:To suppress the increase of radioactive alpha particles with time and to obtain high reliability by specifying the purity, the content of radioactive isotopes, and the radioactivities of the radioactive isotopes and <210>Pb among the same respectively to specific values and specifying the count value of the radioactive alpha particles to a specific value. CONSTITUTION:The increase of the radioactive alpha particles with time is suppressed by meeting the conditions of >=99.999% purity, <5ppb content of the radioactive isotopes, <=0.2pci/g radioactivity by the radioactive isotopes, <=0.15pci/g radioactivity exhibited by the <210>Pb among the radioactive isotopes, and <=0.1CPH/cm<2> count number of the radioactive alpha particles. An example of a semiconductor device consists of a ceramics case 1, a semiconductor element 2 brazed to the bottom of the cavity of said case, a bonding wire 3 consisting of Au, etc., a sealing plate 4 brazed to the case 1, and lead wires 5. The generation of the memory error by the radioactive alpha particles is obviated over a long period of time by using such high-purity Pb brazing filler metal for razing, by which the high reliability is obtd. |
