PURPOSE: To prevent occurrence of wire-bonding defects caused by flow out of Au.Si eutectic alloy by separating a gold plated layer at the wire-bonded portion of a tab lead and a gold plated layer of a tab portion by a non-gold-plated region.
CONSTITUTION: A lead frame comprises a tab portion 2 which is connectted to a semiconductor pellet, and a tab 1, and leads 3 which are radially arranged around the tab portion. Gold is plated on the tab 2, the tips of the lead to which wire bonding is made, and a portion 5 of the tab-lead 1 to which wire bonding is made, i.e. the shaded area. This lead frame is made by plating gold by the use of a mask having a portion which completely bridges the tab portion 2 and the bonding portion 5 of the tab lead in order to separate the plated layer thereof. As a result, flow out of Au.Si eutectic alloy to the plated portion 5 is prevented in the process of bonding the pellet to the tab 2, and occurrence of wire-bonding defects at the portion 5 is prevented.
ADACHI YOSHIO
MOMONA HIROSHI
