| Title |
Contact Resistance and Thermal Cycling Reliability of the Flip-Chip Joints Processed with Cu-Sn Mushroom Bumps |
| Authors |
임수겸(Su Kyum Lim); 최진원(Jin Won Choi); 김영호(Young Ho Kim); 오태성(Tae Sung Oh) |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
Flip chip; chip on glass; mushroom bump; contact resistance; thermal cycling |
| Abstract |
Flip-chip bonding using Cu-Sn mushroom bumps composed of Cu pillar and Sn cap was accomplished, and the contact resistance and the thermal cycling reliability of the Cu-Sn mushroom bump joints were compared with those of the Sn planar bump joints. With flip-chip process at a same bonding stress, both the Cu-Sn mushroom bump joints and the Sn planar bump joints exhibited an almost identical average contact resistance. With increasing a bonding stress from 32 MPa to 44MPa, the average contact resistances of the Cu-Sn mushroom bump joints and the Sn planar bump joints became reduced from 30 mΩ/bump to 25 mΩ/bump due to heavier plastic deformation of the bumps. The Cu-Sn mushroom bump joints exhibited a superior thermal cycling reliability to that of the Sn planar bump joints at a bonding stress of 32 MPa. While the contact resistance characteristics of the Cu-Sn mushroom bump joints were not deteriorated even after 1000 thermal cycles ranging between -40℃ and 80℃, the contact resistance of the Sn planar bump joints substantially increased with thermal cycling. |