SMTA International Conference Proceedings


Author: Todd P. Oman
Company: Delphi Corporation
Date Published: 9/25/2005   Conference: SMTA International

Abstract: Power semiconductors generally require electrical interconnects to both sides of the die. In the case of direct chip attach, wire-bonds are typically used to make the top-side interconnects. The wire-bond process is an expensive, serial process which precludes heat sinking from the top-side of the die. Additionally, power semiconductors typically have active circuitry under the metallization of the bond locations making them vulnerable to mechanical damage during the bonding process.

A method to achieve the top-side interconnects without the shortcomings of the wire-bond process has been developed and will be referred to as bar bond. This method of connection is compatible with both high and low power devices. Bar bond is also compatible with existing surface mount process flows and equipment. Too minimize cost, a goal of bar bond is to not rely on encapsulation or epoxy underfill to maintain solder joint integrity. Reliability testing has demonstrated that this method exceeds the automotive goal of a minimum life of 1000 thermal cycles for temperature extremes of -40 to +150ºC .

Key words: power semiconductor, solder joints, direct chip attach.

Members download articles for free:

Not a member yet?

What else do you get when you join SMTA? Read about all of the benefits that go along with membership.

Notice: Sharing of articles is restricted to just your immediate work group. Downloaded papers should not be stored on an external network or shared on the internet.


SMTA Headquarters
6600 City West Parkway, Suite 300
Eden Prairie, MN 55344 USA

Phone +1 952.920.7682
Fax +1 952.926.1819