Mechanical, electrical, and thermal reliability of Sn-58wt.%Bi solder joints with Ag-decorated MWCNT for LED package component during aging treatment

The effect of aging on reliability of Sn-58 wt%Bi solder joint with Ag-decorated multi-walled carbon nanotubes (Ag-MWCNTs) was investigated for the LED package components. The mechanical, electrical and thermal characteristics of the solder joints with various Ag-MWCNT contents were examined under aging treatment. Ag-MWCNTs were synthesized by using a colloidal method and the nanocomposite solder paste was fabricated by mechanically mixing the Ag-MWCNTs with Sn-58 wt%Bi solder paste. The flip-chip light emission diode (FCLED) package component was bonded on the substrate with Cu pad finished organic solderability preservative (OSP). And then these were isothermally aged at 85 degrees C up to 1000 h in an oven. The mechanical, electrical and thermal property of solder joints was evaluated by using shear test, measuring the electrical resistance and thermal transient test, respectively. The bonding strength of all of the solder joints decreased and the electrical resistance of the solder joints increased with increasing aging time. The bonding strength of the solder joints with 0.05Ag-MWCNTs was 12% higher than those of other solder joints. And the electrical and thermal resistance of the solder joints exhibited the lowest resistance with 0.1Ag-MWCNTs and 0.05Ag-MWCNTs after aging for 1000 h, respectively.