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The electromigration behavior of eutectic SnAg solder reaction couples was studied at various temperature (25 and 120°C) when the current density was held constant at 104 A/cm2 or 5×103 A/cm2. Under the current density of 104 A/cm2, scallop type Cu6Sn5 spalls and migrates towards the direction of electron flow at room ambient temperature (25°C), but transforms to layer type Cu3Sn and leaves Kirkendall voids in it at high ambient temperature (120°C). Under the current density of 5×103 A/cm2 plus room ambient temperature, no obvious directional migration of metal atoms/ions is found. Instead, the thermal stress induced by mismatch of dissimilar materials causes the formation of superficial valley at both interfaces. However, when the ambient temperature increases to 120°C, the mobility of metal atoms/ions is enhanced, and then the grains rotate due to the anisotropic property of β-Sn.
The electromigration behavior of eutectic SnAg solder reaction couples was studied at various temperatures (25 and 120 ° C) when the current density was held at 104 A / cm2 or 5x103 A / cm2. , scallop type Cu6Sn5 spalls and migrates towards the direction of electron flow at room ambient temperature (25 ° C), but transforms to layer type Cu3Sn and leaves Kirkendall voids in it at high ambient temperature (120 ° C). Under the current density of而且, when the ambient temperature, 5 × 103 A / cm2 plus room ambient temperature, no obvious directional migration of metal atoms / ions is found. Instead, the thermal stress induced by mismatch of dissimilar materials causes the formation of superficial valley at both interfaces. However, when the ambient temperature increases to 120 ° C, the mobility of metal atoms / ions is enhanced, and then the grains rotate due to the anisotropic property of β-Sn.