Lead frame for semiconductor

Abstract

Abstract PURPOSE:To obtain a lead frame which is inexpensive and excellent in assembling workability by providing a plating solder layer partially on the surface of a base body whereon a layer of Ni or an Ni alloy or a layer of Co or a Co alloy is formed. CONSTITUTION:An Ni-P alloy plated layer 4 is formed on the tab 2 of a base body 1 made of an Fe-42% Ni alloy and a lead terminal 3. Furthermore, the plating solder layer 5 containing Pb of 95% is laid on the tab 2, and after a heated semiconductor element 6 is pressed thereon, a wire connection 7 of the element 6 with the lead terminal 3 is conducted. It is desirable that the plating solder layer 5 has a composition containing Pb of 80-98%, since the element is cracked frequently by a heat shock in a cycle of 150 deg.C and -50 deg.C when the content of Pb is less than 80%. when it is above 98%, the heat connectivity is reduced. The alloy layer may be formed on the whole surface or in a part thereof. This constitution enables preparation of the lead frame which is inexpensive, whereby the assembling workability is improved remarkably and which enables attainment of a highly reliable device.

Inventors

• 👤 Ryozo Yamagishi
• 👤 Osamu Yoshioka

Bibliographic Details