Defects in any link in the PCBA processing process will cause the quality of the PCBA board to fail. The consequence is that the quality of the customer’s product will be affected, the delivery will be delayed, and the reputation of the factory will be poor. Therefore, PCBA processing plants are very important to supervise the production process.
1. PCB circuit board manufacturing
It is very important to hold a pre-production meeting after receiving an order for PCBA processing. It mainly analyzes the process of PCB Gerber files and submits manufacturability reports according to different customer needs. Many small manufacturers do not pay attention to this, but they tend to prefer this. Not only is it easy to produce poor quality problems caused by poor PCB design, but also a lot of rework and repair work.
2. Purchase and inspection of PCBA incoming components
It is necessary to strictly control the procurement channels of components and obtain goods from large traders and original manufacturers, so as to avoid the use of second-hand materials and counterfeit materials. In addition, it is necessary to set up a special PCBA incoming material inspection post to strictly inspect all items to ensure that the components are free of faults.
PCB: Check the temperature test of the reflow oven, whether the fly-line vias are blocked or leaking, whether the layout is bent, etc.
IC: Check whether the screen printing and BOM are exactly the same, and keep it at constant temperature.
Other commonly used materials: check screen printing, appearance, power-on measurement, etc.
3. SMT patch processing
Solder paste printing and reflow oven temperature control system are the key points of assembly, and laser stencils with higher quality requirements and better processing requirements are required. According to the requirements of PCB, part of the need to increase or decrease the steel mesh, or U-shaped holes, just make the steel mesh according to the process requirements. Among them, the temperature control of the reflow oven is very important for the wetting of the solder paste and the firmness of the steel mesh, and can be adjusted according to the normal SOP operation guide.
4. Plug-in processing
In the plug-in process, it is critical for mold designers who have undergone wave soldering. How to use the mold to maximize the yield rate is a process that PE engineers must continue to practice and summarize.
5. Program firing
In the previous DFM report, customers can be advised to set up some test points on the PCB to test the circuit continuity of the circuit in PCBA processing after all the components of the PCB are soldered. If conditions permit, customers can be required to provide a program, and the program can be burned into the main control IC through the burner, so that various touch actions can be tested more intuitively to verify the integrity of the entire PCBA function.
6. PCBA processing board test
For orders with PCBA test requirements, the main test content includes ICT (circuit test), FCT (functional test), burn test (aging test), temperature and humidity test, drop test, etc.