Inherent quality problems of SMT processed products

Inherent quality problems of SMT processed products
More and more people are aware of the adverse consequences of poor quality SMT surface mounted products This shows that manufacturers urgently need to check the production process and install necessary automatic optical monitoring equipment to reduce losses caused by poor quality Users have higher and higher requirements for miniaturization of electronic products Now we need it, in the future, mobile phones, computers, digital cameras, etc Smaller, better quality, better efficiency, need to be more efficient With the demand for miniaturization of electronic products, people are facing a severe challenge to produce products with hundreds of parts that are invisible under normal conditions The SMT manufacturing industry faces the following major challenges:
The first is to try to assemble sand sized components on hundreds or even millions of PCBs.
Circuit board

The distribution density of PCB components is very high During the assembly process, due to many factors, the equipment used may have unexpected or frequent system positioning deviations These factors include: aging problem; The ability to place 0402 or 0201 components; Set problems to maintain accurate placement; The time problem before the production of 0402 type plate is due to the accumulation of debris suction nozzle; Number of installed parts; The ability of the operator to turn the reel In addition, there is the quality problem of standard solder These are enough to make people understand that the cost of inferior products is huge It was too late to discover an error Some errors were found in the online test Up to 60% errors can be found in online testing Many products cannot be tested online due to high assembly density or design features;  some errors are Found during functional testing (if this type of testing is performed on the product).  Most defects are discovered by consumers Most of them are either affected by inferior products or have read reports about inferior records and a large number of returned products in newspapers, which is much more expensive than repair
Secondly, these errors are caused by the absence of automatic optical testing equipment in the production process Many of these errors are undetectable to the naked eye Even if there is time to check a board for a few hours, it is useless However, the only test method used in many countries, including China, is visual inspection What is more surprising is that the average time for each inspector to inspect a circuit board containing more than 400 small parts is 10 minutes For the same inspector, even if he has 40 minutes to check a circuit board, the circuit board has larger components and simpler components, and 90% of the problems cannot be seen This problem is not only related to medium and high capacity mounters Please note that high mix low volume SMT products have similar problems In many cases, rapid conversion will usually occur in surface mount processes