Virtual soldering in SMT processing affects product quality, and it is necessary to optimize welding materials and processes, strengthen PCB board and component management, finely control each process, and strictly inspect and repair quality. Avoid virtual soldering and enhance product competitiveness.
1、 Reasons for virtual soldering
Virtual soldering is characterized by weak solder joints, insufficient wetting of solder pads or component pins, resulting in poor electrical connections. The main reasons include:
Improper control of welding temperature and time; Poor quality of welding materials; There are quality issues with the PCB board and components; Poor process control and improper operation during the process.
2、 Preventive measures
Optimize welding materials and processes: Select high-quality welding materials, control welding temperature and time reasonably, and adjust the reflow soldering temperature curve.
Strengthen the management of PCB boards and components: strict moisture-proof treatment, baking treatment of components, inspection of PCB board quality: ensure that the PCB board is free of oxidation, oil pollution and other pollution, optimize PCB board design, ensure that the solder pad spacing and area meet standard specifications, and reduce the risk of solder loss.
Ensure process quality: The screen printing and dispensing processes ensure that the solder paste or adhesive is evenly applied to the solder pads to avoid insufficient soldering. Mounting and curing process, using high-precision surface mount machines to ensure accurate placement of components onto PCB boards. During the curing process, strictly control the curing temperature and time to fully melt the patch adhesive and firmly bond the components. Reflow soldering process ensures uniform temperature in the reflow soldering furnace, avoiding local overheating or overcooling. After soldering, the appearance of the solder joints should be inspected in a timely manner.
Quality inspection and repair: Advanced testing equipment such as X-ray inspection system, AOI (Automatic Optical Inspection), etc. are used to comprehensively inspect the welded PCB board and promptly detect defects such as virtual soldering. Establish a repair mechanism: For the detected virtual welding problems, immediate repair processing is carried out to ensure that all products meet quality requirements.
