Ultrasonic Casting of Off-Eutectic Tin Bismuth Solder Alloy for Mechanical Property Testing

Knowledge of solder mechanical properties is essential when designing electronic assemblies for use in harsh environments like those that exist in automotive or aerospace applications. However, information on solder mechanical properties is limited because fabricating material samples in a form factor used for typical mechanical testing is difficult. Conventional casting processes are prone to void formation and dross inclusion which can degrade the quality of test results acquired and often produce high degrees of variability. The current work describes in detail a novel casting process which seeks to address these solder sample fabrication issues. The non-conventional process applies ultrasonic excitation to eliminate voiding by breaking up dross inclusions and other voids, so none can form within the melt upon solidification. Cast ingots are machined then undergo non-destructive screening to ensure material consistency within the regions critical to producing good test results prior to being subjected to destructive mechanical testing. This ultrasonic casting process is applied to the testing of an off-eutectic Tin-Bismuth solder alloy and its ambient tensile and compressive stress versus strain properties are evaluated. The improvement in result repeatability for the various tested properties due to the ultrasonic casting are assessed and sample size considerations discussed.

PENGARUH KANDUNGAN UNSUR Ag PADA PADUAN SOLDER BEBAS TIMBAL TERHADAP SIFAT MEKANIS DAN FISIS Sn-0.7Cu-“X”Ag

In this research was carried out of lead free solder sample of Sn-Cu-Ag to characterized how far the effect of Ag composition on Lead Free Solder of Sn0.7CuxAg to replace SnPb alloy. The research will be carried out such us specific gravity, melting point, micro structure, shear strength, and micro hardness value The impact was added Ag to Sn -Cu-Ag has shown that shear strength for each at 61% on material Sn-0.7Cu-1Ag,73% at material Sn-0.7Cu-1.5Ag and 94% on material Sn-Cu-2Ag. The results has shown that on Sn-0.7Cu-1Ag material getting melting point bellow Sn -Pb that is 1820C.