I. Field of the Invention
The present invention relates to a bonding wire used for a semiconductor device, a semiconductor device including a bonding wire, and a method for connecting a bonding pad of the semiconductor device to a lead frame.
II. Description of the Prior Art
A semiconductor device such as an IC (integrated circuit) generally includes a chip into which a semiconductor element is built, a plurality of bonding pads for leading electrodes, and a lead frame disposed to surround the chip. The bonding pads are respectively electrically connected to the lead frame by means of bonding wires. The conventional bonding wire consists of a bare gold or aluminum wire.
Along with the development of a high packing density of the IC, the distance between adjacent bonding pads has decreased. For example, in a large scale integrated circuit (LSI), the pitch of bonding pads is often less than 200 .mu.m. In this manner, as the pitch of bonding pads is decreased, adjacent bonding wires come closer to each other. In the process of bonding and/or a subsequent process, adjacent bonding wires may come into contact with each other, resulting in short-circuiting and erratic operation of the semiconductor device.