How To Do A Good Job in The Quality Control Of Printed Circuit Board Assembly?
The entire process of printed circuit board assembly includes component procurement and inspection, SMT patch and DIP plug-in post-soldering, and testing. The entire printed circuit board assembly process involves a wide range of aspects and includes many quality control details. If there is no very strict quality control standard, it will lead to abnormal quality of the final product after the assembly of the printed circuit board. If the inspection standard is not strict or there is no standard to follow, it is very likely that a small error will occur, resulting in the entire batch of PCBA circuit boards. Scrapped or need to be repaired, resulting in serious quality accidents. So, how to do a good job in the quality control of printed circuit board assembly(PCB assembly) and processing?
1. Printed circuit board assembly and processing
After receiving the order for PCB assembly, we need to analyze the Gerber file first, pay attention to the relationship between the hole spacing of the PCB and the bearing capacity of the board, do not cause bending or breakage, and whether high-frequency signal interference and impedance are considered in the wiring. These factors need to be inspected in the early stage, which can avoid some problems in the later assembly and manufacturing process, resulting in waste of resources and time costs for rework.
2. Procurement and inspection of components
In order to ensure the stability and quality of the components, it is necessary to strictly control the supplier's purchase channels and the qualifications of the suppliers. It is generally designated to 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 inspection post to strictly inspect the following items to ensure that the components are fault-free. PCB: Check the reflow oven temperature test, whether the vias without flying leads are blocked or leaking ink, whether the board surface is bent, etc. IC: Check whether the screen printing is exactly the same as the BOM, and keep it at constant temperature and humidity. Other commonly used materials: check screen printing, appearance, power-on measurements, etc. As a professional electronic manufacturing service company, TECOO has a comprehensive supply chain management system, which can flexibly purchase components to avoid missing components, and we will review each supply chain, select international manufacturers for each component, and confirm the brand with customers one by one , part number, specification, and then check each incoming material for quality and reliability. We put Six Sigma philosophy into practice for flawless efficiency.
3. SMT chip processing
Tin printing and reflow oven temperature control are the key points. It is very important to use laser stencils with good quality and in line with process requirements. According to the requirements of the PCB, some parts need to increase or decrease the stencil hole, or use U-shaped holes to make the stencil according to the process requirements. The furnace temperature and speed control of reflow soldering is very critical to the infiltration of solder paste and soldering reliability, and it can be controlled according to the normal SOP operation guidelines. In addition, AOI testing needs to be strictly implemented to minimize defects caused by human factors.
4. DIP plug-in processing
In the process of insert processing, the details of mold design for wave soldering are the key. How to use the mold carrier to greatly improve the yield rate is the process experience that PE engineers must constantly practice and summarize.
5.Testing
For each product, we do 100% functional test according to customer's requirement. If customer doesn't have it, we will strongly request it. If there is still no required file, our engineer will make a simplified test fixture based on product's performance and schematic diagram. Each product will be labeled after passing the test.For Tecoo, our goal is to provide customers with high-qualified product and to be an inspection-free supplier.
If there is no problem with the PCB circuit board, there is no problem with the components. We can pay attention to the control of details in the entire processing process, and the quality of the entire printed circuit board assembly and processing can be guaranteed. In fact, the knowledge of the printed circuit board assembly process and PCBA incoming materials is far more than that, and each of the above points can be explained in detail in a long space. If you have needs and interests in PCB assembly, please contact us.
