Investigation on the Reliability of Solder Bumps Applying Polyimide as the Passivation Layer
| Autor: | Chih Hao Yu, 尤志豪 |
|---|---|
| Rok vydání: | 2001 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 89 This research was to investigate the feasibility of the Si/Ta/Ta-Cu/Cu/Au/EN/solder solder bump structure applying polyimide as the passivation layer. Furthermore, the shear strength of solder bumps and the diffusion behavior of constitutive elements was investigated after reliability test by aging at 150℃ and at 85℃/85RH. The fracture model of solder bumps after shear test was investigated by observing the failure morphology. The SEM cross-section morphology of solder bumps revealed a good adhesion between polyimide and Ni-P layer after reliability test. The average shear strength of solder bumps after reflow was about 60 g, and the fracture occurred at the solder. It was also found that heat treatment tends to downgrade the shear strength of solder bumps. After 1000 hours of reliability test with 150℃ aging and 85℃/85RH test, the average shear strength of solder bumps was about 50 g, while the fracture still occurred at the solder. The SEM line scanning results revealed that the Cu atoms did not penetrate through the 3.3μm Ni-P layer after 150℃heating or 85℃/85RH testing for 1000 hours. The pull test results showed that the adhesion strength of Si/PI decreased after 85℃/85RH test for 1000 hours. The pull test results of Si/Ta/Ta-Cu/Cu/PI showed that the reliability test degrades the adhesion strength of Cu/PI. For the Si/Ta/Ta-Cu/Cu/Au/PI structure, the fracture of pull test occurred at the Au/PI interface after 150℃ heating for 100 hours with an adhesion strength of less than 1 kpsi. On the other hand, the Si/Ta/Ta-Cu/Cu/EN/PI structure did not show degradation in adhesion strength of the EN/PI bonding after reliability test. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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