TY - JOUR
T1 - Bonding dynamics of compliant microbump during ultrasonic bonding investigated by using Si strain gauge
AU - Iwanabe, Keiichiro
AU - Nakadozono, Kenichi
AU - Senda, Yousuke
AU - Asano, Tanemasa
PY - 2016/6/1
Y1 - 2016/6/1
N2 - The bonding dynamics of a cone-shaped microbump during ultrasonic bonding are investigated by in situ measurements of the strain generated in a substrate using a piezoresistance strain sensor. The strain sensor is composed of a pair of p-and n-type piezoresistance gauges to extract strain components in the ultrasonic vibration along the plane parallel to the substrate surface and along the direction perpendicular to the surface. Flipchip bonding is performed at room-temperature. The time evolution of the strain generated in the substrate according to the load-up of pressing force and application of ultrasonic vibration is clearly detected. The softening of the bump metal during the application of ultrasonic vibration is clearly observed. Results of a comparative study between the bonding of a cone-shaped microbump and that of a flat-top microbump suggest mechanical stress concentration near the top end of the cone-shaped microbump, which results in the transformation of the crystal texture of the bump from grains to fine crystallites.
AB - The bonding dynamics of a cone-shaped microbump during ultrasonic bonding are investigated by in situ measurements of the strain generated in a substrate using a piezoresistance strain sensor. The strain sensor is composed of a pair of p-and n-type piezoresistance gauges to extract strain components in the ultrasonic vibration along the plane parallel to the substrate surface and along the direction perpendicular to the surface. Flipchip bonding is performed at room-temperature. The time evolution of the strain generated in the substrate according to the load-up of pressing force and application of ultrasonic vibration is clearly detected. The softening of the bump metal during the application of ultrasonic vibration is clearly observed. Results of a comparative study between the bonding of a cone-shaped microbump and that of a flat-top microbump suggest mechanical stress concentration near the top end of the cone-shaped microbump, which results in the transformation of the crystal texture of the bump from grains to fine crystallites.
UR - http://www.scopus.com/inward/record.url?scp=84974652921&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84974652921&partnerID=8YFLogxK
U2 - 10.7567/JJAP.55.06GP22
DO - 10.7567/JJAP.55.06GP22
M3 - Article
AN - SCOPUS:84974652921
VL - 55
JO - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
JF - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
SN - 0021-4922
IS - 6
M1 - 06GP22
ER -