Effect of Thermal Cycling on Repaired Lead and Lead-Free Solder Joints
Department
Materials Science and Engineering
Major
Metallurgical Engineering
Research Advisor
O'Keefe, Matthew
Advisor's Department
Materials Science and Engineering
Funding Source
CAMT - Air Force
Abstract
Numerous laws have been passed in recent years either prohibiting or greatly limiting the use of lead (Pb). As a result, tin lead (SnPb) solders are being replaced with lead free (LF) solders in assembly of electronic products. This study examined the effect of thermal cycling on SnPb, LF, and mixed SnPb/LF repaired solder joints. Four different types of electronic components were originally attached to printed circuit boards using SnPb solders. The solder joints were then repaired with either SnPb or LF solders and components. The repaired boards were then subjected to 1000 thermal cycles between -55°C to 125°C. Resistance measurements were taken before, during, and after thermal cycling. All solder joints were then examined with a digital imaging system to look for cracks and opens. The components were then sectioned, mounted and polished to allow examination of the solder/solder pad interface and changes in microstructure.
Biography
Kenneth Doering is an undergraduate student at UMR, majoring in Metallurgical Engineering.
Research Category
Engineering
Presentation Type
Poster Presentation
Document Type
Poster
Presentation Date
12 Apr 2006, 1:00 pm
Effect of Thermal Cycling on Repaired Lead and Lead-Free Solder Joints
Numerous laws have been passed in recent years either prohibiting or greatly limiting the use of lead (Pb). As a result, tin lead (SnPb) solders are being replaced with lead free (LF) solders in assembly of electronic products. This study examined the effect of thermal cycling on SnPb, LF, and mixed SnPb/LF repaired solder joints. Four different types of electronic components were originally attached to printed circuit boards using SnPb solders. The solder joints were then repaired with either SnPb or LF solders and components. The repaired boards were then subjected to 1000 thermal cycles between -55°C to 125°C. Resistance measurements were taken before, during, and after thermal cycling. All solder joints were then examined with a digital imaging system to look for cracks and opens. The components were then sectioned, mounted and polished to allow examination of the solder/solder pad interface and changes in microstructure.
