Pan Pacific Symposium Conference Proceedings


Authors: L. Pymento, W.T. Davis, and T. Godown
Company: IBM Corporation
Date Published: 1/17/2006   Conference: Pan Pacific Symposium

Abstract: The transition from Sn-Pb to Pb-free assembly as directed by the EU implies that all components are available in a Pb-free finish and can withstand the higher temperature profiles required to reflow Pb-free solder. However, during this transition, it is possible that certain designs will be required to accommodate components that are RoHS (Restriction of Hazardous Substances) compliant with a limitation on peak temperature, or a ball grid array (BGA) package may only be available in a SAC finish forcing a solution using leaded paste and an optimized reflow profile that allows for dissolution of the SAC (SnAgCu) ball composition, and at the same time does not violate the peak temperature specifications. This approach is referred to as a Mixed Assembly solution and is the focus of this study. Mixed Assembly requires significant process development and reliability studies to prove it as a viable option on a given product. Though these studies demonstrated that Mixed Assembly with an optimized reflow profile is a viable solution for a specific planar, one cannot conclude that this specific solution can be generically applied to all Mixed Assembly applications.

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