| Summary: | 博士 === 國立中正大學 === 機械工程學系暨研究所 === 102 === One of the important issues of a lead-free solder joint package is to design proper layers of structure and adjust manufacturing parameters so that the electric performance and the strength of the solder joint could reach the design requirements. The mechanical integrity of solder ball joints under dynamic loading is generally evaluated by means of a JEDEC standard impact test at high speed (0.01 m/s to 1 m/s). Such tests result in a higher incidence of interfacial fracture than low-speed shear tests, and provide valuable insights into the load–displacement response and failure mode of the solder ball joint. Furthermore, interfacial cracking failure of the solders at great temperature variations is of significant concern for electronic assemblies that operate in harsh environments. Therefore, ball shear impact tests with environmental thermal effects would be set up to study the impact failure modes for the solder joints under different impact temperatures. Accordingly, the present study proposes a novel technique for evaluating the failure characteristics, high-speed impact strength and energy absorbance of the solders at the chip level within a temperature control system. In this research, a method has been proposed for observing the fracture phenomenon in solder ball joints under high-speed impacts using a high-speed framing camera that captures approximately 500,000 frames per second (fps). Also, computer simulation model of ball shear impact test will be developed to study the constitutive model under high rate deformation. As a result, these proposed approaches provide efficient experimental method and accurate numerical analysis tools for high speed impact problems.
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