Aluminum bump bonding for fine aluminum wire

Abstract

The invention includes a packaged semiconductor device in which the bond wires are bonded to the leads with an aluminum bump bond. The semiconductor device is mounted on a leadframe having leads with a nickel plating. To form the bump bond between a fine aluminum wire, such as a 2 mil diameter wire, and the lead, an aluminum bump is bonded to the nickel plating and the wire is bonded to the bump. The bump is aluminum doped with nickel and is formed from a large diameter wire, such as a 6 mil diameter wire.

Description

FIELD OF THE INVENTION [0001] This invention relates to the bonding application of aluminum wire to a surface such as a leadframe or a contact on a semiconductor device. BACKGROUND OF THE INVENTION [0002] Conventionally, aluminum bond wire connecting the features of a semiconductor die to the leads of a leadframe in a semiconductor package are bonded directly to the leadframe. The common issues associated when using this method with fine aluminum bond wire (less than about 3 mil diameter) include heel break and bond lift. Heel lift occurs when the bonding parameters are set too high and the bond wire breaks at the bond, potentially resulting in the loss of electrical communication between the semiconductor feature and the lead. Bond lift generally occurs when the bonding parameters are set too low and the bond disengages from the lead. Thus, there is a narrow range of bonding parameters that will result in a resilient bond. Further, the bonding parameters for bonding fine aluminum w...

AI Technical Summary

Benefits of technology

[0008] An advantage of the present invention is that the aluminum to nickel bond is achieved through the large diameter bump and the fine aluminum wire is the able to be bonded to an aluminum surface. While the fine wire aluminum to nickel bond has been shown to be unreliable and particularly sensitive to surface conditions and bonding parameters, the large diameter wire aluminum to nickel bond has been shown to be robust and less sensitive to surface conditions and bonding parameters. Further, the invention shows a great reduction in bond lift and heel crack conditions.

is that the aluminum to nickel bond is achieved through the large diameter bump and the fine aluminum wire is the able to be bonded to an aluminum surface. While the fine wire aluminum to nickel bond has been shown to be unreliable and particularly sensitive to surface conditions and bonding parameters, the large diameter wire aluminum to nickel bond has been shown to be robust and less sensitive to surface conditions and bonding parameters. Further, the invention shows a great reduction in bond lift and heel crack conditions.

Problems solved by technology

While the fine wire aluminum to nickel bond has been shown to be unreliable and particularly sensitive to surface conditions and bonding parameters, the large diameter wire aluminum to nickel bond has been shown to be robust and less sensitive to surface conditions and bonding parameters.

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