Department
Materials Science and Engineering
Major
Metallurgical Engineering
Research Advisor
O'Keefe, Michael J.
Advisor's Department
Materials Science and Engineering
Funding Source
Center for Aerospace Manufacturing Technologies (CAMT) through the Air Force Research Laboratory (AFRL)
Abstract
Due to international environmental regulations that took effect in July 2006, the replacement of lead-tin solder with lead-free solder is occurring globally in the electronics industry. Although aerospace and military applications are exempt from the regulations, the shift to lead-free solder for high volume consumer products, such as cell phones, is impacting aerospace and military electronic assemblies as suppliers abandon lead-tin solder and ship only lead-free components. The switch to lead-free alloys is already being seen by defense contractors and military installations in Missouri and throughout the United States. The reliability of lead-free solder joints in military and aerospace applications is not known, resulting in new research opportunities in this area. To investigate the use and impact of lead-free solder on military applications, the University of Missouri - Rolla (UMR) has teamed with Boeing Integrated Defense Systems in St. Louis and Northrop Grumman Interconnect Technologies in Springfield to research the reliability of repaired and reworked lead-tin, lead-free, and mixed lead-tin/lead-free solder joints for military and aerospace applications. Evaluations have been performed on components soldered to test boards, including the effect of thermal cycling between -55°C and 150°C, vibration testing up to 5 g's, and measuring the melting point of the various solder alloys. Results indicate a dramatic change in microstructure before and after thermal cycling that may impact long term reliability. Vibration testing indicated that the type of component and location on the test board affects reliability more than the type of solder. The melting temperature of lead-free solder with varying amounts of lead tin contamination can change significantly, up to 30°C, making rework and repair operations difficult to control. The implication of these results on the use of leadfree solder for military applications will be summarized.
Biography
Brandon is a senior in Metallurgical Engineering. He plans on continuing with his education by obtaining an M. S. degree after graduation in May. In his free time, he enjoys golfing, fishing, and anything outdoors.
Kenneth is a senior at UMR studying metallurgical engineering. He is the officer of worship music for the Christian Campus Fellowship. He plans on attending graduate school and acquiring an M. S. in metallurgical engineering.
Research Category
Engineering
Presentation Type
Poster Presentation
Document Type
Poster
Location
Havener Center, Carver-Turner Room
Presentation Date
11 April 2007, 9:00 am - 11:45 am
Investigation of Lead-Free Solder for Military Applications
Havener Center, Carver-Turner Room
Due to international environmental regulations that took effect in July 2006, the replacement of lead-tin solder with lead-free solder is occurring globally in the electronics industry. Although aerospace and military applications are exempt from the regulations, the shift to lead-free solder for high volume consumer products, such as cell phones, is impacting aerospace and military electronic assemblies as suppliers abandon lead-tin solder and ship only lead-free components. The switch to lead-free alloys is already being seen by defense contractors and military installations in Missouri and throughout the United States. The reliability of lead-free solder joints in military and aerospace applications is not known, resulting in new research opportunities in this area. To investigate the use and impact of lead-free solder on military applications, the University of Missouri - Rolla (UMR) has teamed with Boeing Integrated Defense Systems in St. Louis and Northrop Grumman Interconnect Technologies in Springfield to research the reliability of repaired and reworked lead-tin, lead-free, and mixed lead-tin/lead-free solder joints for military and aerospace applications. Evaluations have been performed on components soldered to test boards, including the effect of thermal cycling between -55°C and 150°C, vibration testing up to 5 g's, and measuring the melting point of the various solder alloys. Results indicate a dramatic change in microstructure before and after thermal cycling that may impact long term reliability. Vibration testing indicated that the type of component and location on the test board affects reliability more than the type of solder. The melting temperature of lead-free solder with varying amounts of lead tin contamination can change significantly, up to 30°C, making rework and repair operations difficult to control. The implication of these results on the use of leadfree solder for military applications will be summarized.
