We propose a new soldering process and a system for a quad flat package IC (QFP-IC). The incident line-formed laser beam converted by this system can realize an external quadrangular form line for the non-contact regional heating, to provide thin and light weight electronic packages as required. The laser beam pumped by an yttrium aluminum garnet (YAG) laser oscillator is split into four beams. Using a galvano motor, which can scan the reflection mirror with high frequencies, the laser beam can change the heating line. The soldering time for QFP-IC of 100 pins with the 0.65 mm pitch was 6 s. As the regional heating just only junctions, the temperature in the resin package was lower than 141 °C after solder fusion. From the experimental result, it is confirmed that this method is less damage to a resin package than a conventional whole heating method.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics