Byoung-Joon Kim

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The electrical resistance Cu film on flexible substrate was investigated in cyclic bending deformation. The electrical resistance of 1 µm thick Cu film on flexible substrate increased up to 120 % after 500,000 cycles in 1.1 % tensile bending strain. Crack and extrusion were observed due to the fatigue damage of metal film. Low bending strain did not(More)
The intermetallic compound (IMC) growths of Cu pillar bump with shallow solder (thin Sn thickness) were investigated during annealing or current stressing condition. After reflow, only Cu<inf>6</inf>Sn<inf>5</inf> was observed, but Cu<inf>3</inf>Sn formed and grew at Cu pillar/Cu<inf>6</inf>Sn<inf>5</inf> interface with increasing annealing and current(More)
Cu pillar bumps with eutectic SnPb solder were annealed and their microstructures were investigated. Linear relationship was observed between thickness of intermetallic compounds (IMCs: Cu<sub>6</sub>Sn<sub>5</sub>, Cu<sub>3</sub>Sn) and square root of time at 120 and 150degC. Kirkendall voids, formed by the diffusivity differences between Cu and Sn, were(More)
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