Abstract
The solderability of QFP (Quad Flat Package) outer lead was investigated using the laser soldering process. An Nd:YAG laser system was constructed for this experiment, and the QFP outer lead was scanned by laser beam one by one. The process variables for the laser soldering were the scanning time of laser bean and the laser power. Sn-37%Pb and Sn-3.5%Ag pastes were chosen for solders, and the fluxes contained in the pastes were RMA (Rosin Mildly Activated). Experimental results showed that the molten solder of Sn-37%Pb wetted well on joints with a concave shape with a scanning time of over 400ms and the laser beam power of 5 and 5.9W. Under similar conditions, the molten solder of Sn-3.5% Ag also showed good wettability. The length of the solder joint was slightly increased with increasing laser beam power from 3 to 5.9W.
| Original language | English |
|---|---|
| Pages (from-to) | 317-321 |
| Number of pages | 5 |
| Journal | Metals and Materials International |
| Volume | 5 |
| Issue number | 3 |
| DOIs | |
| State | Published - Jun 1999 |
Keywords
- Nd:YAG laser
- QFP outer lead
- Reflow soldering
- Sn-37%Pb and Sn-3.5%Ag pastes
- Solderability