Analysis of SMT Quality Defects from Paste Testing
It is well known that most of the defects in SMT assembly come from solder paste printing. Some publications and companies even pointed out that the number of such defects accounted for 74% of the total number of defects.
Another indisputable fact is that the solder paste volume is an important indicator of solder joint quality and reliability.
The use of solder paste on the PCB solder paste 100% of the solder paste detection (SPI) will help to find the printing process defects and trends generated in order to quantify the printing process of the process parameters to ensure the best print quality, But also through the lowest rework (such as cleaning the circuit board) to reduce the cost of waste losses, another benefit is the reliability of solder joints will be guaranteed.
If you only detect a few pads on the PCB solder paste status, can not know the other pad solder paste on the printing quality of the situation, the equivalent of blind people like, can not control all.