The formation of calcium lanthanum sulfide powder for infrared ray application

• Main Authors: Shinq-Gwo Chen, 陳興國
• Other Authors: Kwang-Long Lin
• Format: Others
• Language: zh-TW
• Published: 1995
• Online Access: http://ndltd.ncl.edu.tw/handle/87803074989447657485

碩士 === 國立成功大學 === 材料科學(工程)研究所 === 83 === The Al/Mo/Ni thin film was investigated for the potential application as the under bump metallurgy between silicon and solder. The Al/Mo/Ni thin film were prepared by sputtering. It was investigated for the effect of Al，Mo，Ni thin film thickness on the adhesion of Si/Al/Mo/Ni and the effect of wave soldering parameters on the solder bump morphology. The experimental results showed that the increase in thickness of Ni ，degraded the adhesion of Si/Al/Mo/Ni. The sputtering rate of Ni is as low as 1.4*/sec. The increase in conveyor speed during wave soldering roughened the surface appearance of the solder on Si/Al/Mo/Ni . It was uneasy to achieve a complete solder coverage on the bump with Si/Al/Mo/Ni as the under bump metallurgy. It was find to be able to achieve better bump structure when Pd was applied replacing Ni. When the conveyor speed of wave soldering of Si/Al/Mo/Pd is 0.5m/min，the solder can complete wet on the Pd layer. A conveyor speed as high as 1.5m/min，resulted in incomplete solder coverage. Tailing and bridging were observed in the solder bump at unsuitable conveyor speed. Al diffused into the Si substrate when Si/Al/Mo/ Ni/Pb-Sn was heat treated at 150℃for 600 hours，while Al penetrated through Mo to diffuse into the Pd-Sn deposits after 900 hours of heat treatment. A thickness of 6000* Mo were able to prevent interdiffusion betwwen Al and Sn at 600 hours of heat treatment. According to the experimental results，Ni was not appropriate as a diffusion barrier，intead，it acts as a wetting layer.