| Title |
Effect of Shearing Speed on High Speed Shear Properties of Sn1.0Ag0.5Cu Solder Bump on Various UBM`s |
| Authors |
이왕구(Wang Gu Lee); 정재필(Jae Pil Jung) |
| DOI |
https://doi.org/10.3365/KJMM.2011.49.3.237 |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
electrical/electronic materials; soldering; mechanical properties; scanning electron microscopy; SEM; shear test |
| Abstract |
The effect of shearing speed on the shear force and energy of Sn-1.0Ag-0.5Cu solder ball was investigated. Various UBM (under bump metallurgy)`s on Cu pads were used such as ENEPIG (Electroless Nickel, Electroless Palladium, Immersion Gold; Ni/Pd/Au), ENIG (Electroless Nickel, Immersion Gold; Ni/Au), OSP (Organic Solderability Preservative). To fabricate a shear test specimen, a solder ball, 300㎛in diameter, was soldered on a pad of FR4 PCB (printed circuit board) by a reflow soldering machine at 245℃. The solder bump on the PCB was shear tested by changing the shearing speed from 0.01 m/s to 3.0 m/s. As experimental results, the shear force increased with a shearing speed of up to 0.6 m/s for the ENIG and the OSP pads, and up to 1.0 m/s for the ENEPIG pad. The shear energy increased with a shearing speed up to 0.3 m/s for the ENIG and the OSP pads, and up to 0.6 m/s for the ENEPIG pad. With a high shear speed of over 1.0 m/s, the ENEPIG showed a higher shear force and energy than those of the ENIG and OSP. The fracture surfaces of the shear tested specimens were analyzed, and the fracture modes were found to have closer relationship with the shear energy than the shear force. |