| Summary: | 碩士 === 國立中山大學 === 光電工程研究所 === 91 === The joint strength and fracture surface of Sn80％Au20％ and Sn20％Au80％ solders in laser diode package under thermal aging testing were studied experimentally. The AuSn thin film solders were coated on the substrate by electro-plating technique. The Sn80％Au20％ solder was melting point at 210℃,while the Sn20％Au80％solder was melting point at 280℃. During the processes of bonding substrate and Al2O3 together, the N2 and H2 gases were used to achieve the bonding. Then the specimens were aged at 150℃ for one, four, nine, sixteen, twenty-five, thirty-six and forty-nine days. We investigated the bonding strength, voids, IMC thickness and microstructure of the Sn80％Au20％ and Sn20％Au80％ solders. In addition, we also studied the comparison with the process of flux and fluxless.
Under the forty-nine days of aging, the bonding strength of Sn80％Au20％and Sn20％Au80％ solders decreased from 34.3㎏ to 26.0㎏ and from 54.96㎏ to 47.06㎏,respectively. Moreover,the IMC thickness of Sn80％Au20％ and Sn20％Au80％ solders increased from1.07μm to 2.85μm and from 0.83 μm to 1.08 μm, respectively. The Sn20％Au80％ solders showed a better joint strength performance than Sn80％Au20％ due to the less grown of IMC and superior mechanical properties of Au. The fluxless process exhibited the better joint strength performance due to the less grown of voids.
In the study, by using the lead-free and fluxless process, the reliability of laser module package may be improved.
|
|---|
