BGA BACKWARD COMPATIBILITY INTERIM TEMPERATURE CYCLE TEST DATA FOR HARSH ENVIRONMENTS
Authors: Mradul Mehrotra, et al. Company: Raytheon Missile Systems Date Published: 10/11/2007
Abstract: Because of the Restrictions on Hazardous Substance (RoHS) compliance, which went into effect in July 2006, the commercial electronic component manufacturers have been transitioning to lead-free processes in order to meet those directives. As a result, components with traditional tin-lead terminations have become increasingly difficult to procure. Although a plethora of reliability data exist for commercial applications (0 to 100ºC), data for harsh environment requirements (-55 to 125ºC) is still lacking. Therefore, to determine the feasibility of using lead-free technology for Raytheon’s system designs, a comprehensive design of experiment (DOE) was developed using a wide range of component configurations, solder processes and soldering temperatures. BGA backward compatibility continues to be a key concern at Raytheon, primarily because of component obsolescence relative to existing and new designs. This paper will focus mainly on interim temperature cycle test data (-55 to 125ºC) of BGA solder joints, cross-sectional analysis and solder joint elemental mapping.
Key words: Ball Grid Array (BGA), Backward Compatibility, RoHS, Pb-Free, Lead-Free, Soldering, Tin/Silver/Copper (SnAgCu) or SAC, Temperature Cycle.