Quality is the basis of the product, especially in the Pcb factory this high precision industry, is particularly important.In order to achieve the quality goal of high pass-through rate and high reliability in Pcb factory, Pcb design, components, materials, process, equipment, rules and regulations and other aspects must be controlled.Among them, to prevent the main process control in SMT SMT processing industry is particularly important.In each manufacturing process of PCB, all kinds of defects and unqualified hidden dangers must be prevented from flowing into the next process through effective detection means.
The inspection content of circuit board assembly is mainly divided into incoming material inspection, process inspection and surface assembly board inspection, etc. The quality problems found in process inspection can be corrected through rework.The rework cost of unqualified products found in incoming inspection, solder paste printing and pre-welding inspection is relatively low, and the impact on the reliability of electronic products is also relatively small.However, the rework of unqualified products after welding is quite different, because the rework after welding requires re-welding after soldering. In addition to working hours and materials, components and circuit boards may be damaged.As some components are irreversible, such as Flip chip which needs to be filled at the bottom, BGA and CSP need to replant the ball after repair, which is more difficult to repair for embedded technology, multi-chip stacking and other products, so it is necessary to wear anti-static gloves and pu-coated gloves with great rework loss after welding.
It can be seen that process testing, especially the previous several processes testing, can reduce the defect rate and reject rate, can reduce the rework/repair cost, and can also prevent the occurrence of quality hidden trouble from the source through defect analysis.
Final inspection of the surface assembly plate is also important.How to ensure that qualified, reliable products to the hands of users, this is the key to win in the market competition.The final inspection covers many items, including appearance inspection, component location, model, polarity inspection, solder joint inspection, electrical performance and reliability inspection, etc.