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Vol.46, No.9, 585 ~ 593, 2008
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| Title |
| Contact Resistance and Thermal Cycling Reliability of the Flip-Chip Joints Processed with Cu-Sn Mushroom Bumps |
| 임수겸 Su Kyum Lim , 최진원 Jin Won Choi , 김영호 Young Ho Kim , 오태성 Tae Sung Oh |
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| 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. |
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| Key Words |
| Flip chip, chip on glass, mushroom bump, contact resistance, thermal cycling |
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