With the progress of technology, mobile phones, tablet PCs and other electronic products are light, small, portable for the development trend in the SMT processing used in electronic components are also becoming smaller, the previous 0402 resistance capacitive parts are also a large number of 0201 size to replace. How to ensure the quality of high-precision solder paste patch an important issue. Solder joints as a bridge, its quality and reliability of electronic products determines the quality. In other words, in the production process, SMT quality of the final performance of the quality of the solder joints.
At present, in the electronics industry, although the lead-free solder research has made great progress in the world has begun to promote the application, and environmental issues have also been widespread concern, the use of Sn-Pb solder alloy soldering technology is still Is the main connection of electronic circuit technology.
Good solder joints should be in the device's life cycle, its mechanical and electrical properties are not failure. Its appearance as follows:
(1) a complete and smooth bright surface;
(2) the appropriate amount of solder and solder completely cover the welding pad and lead parts, components, a high degree of moderate;
(3) good wettability; welding edge should be thin, solder and pad surface wetting angle of 300 or less as well, the maximum does not exceed 600.
SMT processing visual inspection content:
(1) whether the component is missing;
(2) whether the components posted wrong;
(3) whether the short circuit;
(4) whether the virtual welding; Weld reason is relatively more complex.