PCBAprocessing process involves a series of processes, such as PCB boardmanufacturing, PCBA incoming components procurement and inspection, SMT chipprocessing, plug-in processing, program firing, testing, aging and so on. Thesupply chain and manufacturing chain are long. Any defect in any link will leadto the unqualified quality of PCBA board in large quantities, which will leadto serious consequences. In this case, the quality control of PCBA chipprocessing is a very important quality assurance in electronic processing, sowhat are the main quality control of PCBA processing?
Itis particularly important to hold a pre production meeting after receiving PCBAprocessing order. It mainly analyzes the process of PCB Gerber documents andsubmits manufacturability reports (DFM) according to different customerrequirements. Many small manufacturers do not pay attention to this, but tendto do so. It is not only easy to produce bad quality problems caused by bad PCBdesign, but also a lot of rework and repair work.
2.Purchase and inspection of PCBA components
Itis necessary to strictly control the procurement channels of components andparts, and the goods must be taken from large traders and originalmanufacturers, so as to avoid the use of second-hand materials and counterfeitmaterials. In addition, it is necessary to set up a special PCBA incomingmaterial inspection post to strictly inspect the following items to ensure thatthere is no fault in the components.
PCB:check reflow oven temperature test, no fly wire through hole is blocked or inkleakage, board surface bending, etc.
IC:check whether screen printing and BOM are exactly the same, and store them atconstant temperature and humidity.
Othercommonly used materials: check screen printing, appearance, power measurement,etc.
3.SMT assembly
Solderpaste printing and reflow furnace temperature control system is the key pointof assembly, which requires the use of laser steel mesh with higher qualityrequirements and better meet the processing requirements. According to therequirements of PCB, some steel mesh holes or U-shaped holes need to be addedor reduced, and only steel mesh can be made according to the processrequirements. The temperature control of reflow furnace is very important forthe wetting of solder paste and the firmness of steel mesh welding, which canbe adjusted according to the normal SOP operation guide.
Inaddition, the strict implementation of AOI testing can greatly reduce theadverse effects caused by human factors.4. Plug in processing
Inthe process of plug-in, the mold design of over wave soldering is the key. Howto use the mold to improve the yield of good products is a process that PEengineers must continue to practice and summarize.
5.Programmed firing
Inthe previous DFM report, customers can be advised to set some test points onPCB (test point) to test the circuit continuity of PCBA processing circuitafter PCB welding all parts. If possible, customers can be required to provideprograms, which can be burned into the main control IC through a burner, whichcan test various touch actions more intuitively, so as to verify the functionalintegrity of the whole PCBA.
6.PCBA processing board test
Fororders with PCBA test requirements, the main test contents include ICT (circuittest), FCT (function test), burn test (aging test), temperature and humiditytest, drop test, etc