Summary: | 碩士 === 國立成功大學 === 材料科學及工程學系 === 103 === In this study, silver nanoparticle paste (synthesized by Professor Lien-Chung Hsu’s laboratory at National Cheng Kung University from a mixture of a silver precursor and silver nanoparticles) was applied in shear and fatigue tests of Cu-Cu contacts. After a thermal compression process, the microstructure of the paste became denser and the shear strength increased from 14.0 to 31.2 MPa in the presence of a silver precursor. The fracture surface was within the silver layer instead of at the copper-silver interface. Interlocking joints were observed at the copper-silver interface. The fractures propagated via a void sheet mechanism. Compared to a commercial paste (Advanced Nano Products, Silver Paste DGP-NO), the self-made paste had a higher shear strength (31.2 versus 16.8 MPa), better fatigue resistance (1087 versus 873 cycles), and larger strain. Adding a silver precursor thus improves sintering among silver nanoparticles and also leads to the formation of interlocking joints at the interface, which increase shear strength and strain.
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