| 摘要 |
PURPOSE:To exactly adhere an island to the semiconductor element by coating solder on the island and further coating noble metal such as gold or silver thereon. CONSTITUTION:Thick solder platings 23', 23 are formed at predetermined portions of external lead wires 22, 22' and on the surface of an island 21 of a lead frame 200. Then, thin silver or gold plating 24 is formed on the surface of the wire connecting portions of the plated film 23' and the lead wires 22, 22'. The island is prevented from melting due to heat generation at the element with solder containing, for example, 5% of tin and 95% of lead, and solder containing 60% of tin and 40% of lead is used to the external lead wires by considering the continuity thereof. According to this configuration, solder is not necessary newly to fix the island to the semiconductor element, and solder plating 23' is not oxidized due to heat but exactly adhered thereto. Since the solder is inexpensive, it can be adhered with sufficient thickness to sufficiently absorb the thermal stress caused by the thermal expansion difference between the element and the island so as to prevent the damage of the device. |
