The details of the systematic quality control of solder paste printing and reflow soldering temperature are key points in the PCBA manufacturing process. At the same time, for the printing of high-precision circuit boards with special and complex processes, laser stencils need to be used according to specific conditions to meet higher quality requirements and more demanding processing requirements. According to PCB manufacturing requirements and customer product characteristics, some may need to increase U-shaped holes or reduce holes in stencil. The stencil needs to be processed according to the requirements of PCBA processing technology.
Among them, the temperature control accuracy of the reflow oven is very important for the wetting of the solder paste and the firmness of soldering joints, and can be adjusted according to the normal SOP operation guide. In order to minimize the quality defects of PCBA processing in the entire manufacturing process, strict implementation of the AOI test can greatly reduce the defects caused by human factors.
2. DIP plug-in welding
DIP plug-in soldering is the most important and final process in the circuit board assembly processing. In the process of DIP plug-in soldering, the consideration of the furnace jig for wave soldering is very important. use the furnace fixture to greatly increase the yield rate and reduce soldering defects such as tin bridge, little tin, and tin shortage, and according to different requirements of customers’ products, PCBA processing plants must continue to summarize and accumulate experience in practice to achieve technological upgrading.
3. Programming and testing
The manufacturability report is an evaluation work that we should do once received the customer’s production contract. In the DFM report, we can provide some suggestions to the customer before the PCB processing. For example, set up some key test points on the PCB (test point) for the key test of the continuity and connectivity of the circuit after the subsequent PCBA processing.
When conditions permit, you can communicate with the customer to provide the programming firmware, and then burn the PCBA program into the core master IC through the programmer. In this way, the circuit board can be tested more concisely, so that the integrity of the entire PCBA can be tested and inspected, and defective products can be found in time.
4. PCBA manufacturing test
In addition, many customers looking for one-stop PCBA processing services also have requirements for PCBA back-end testing. The content of this kind of test generally includes ICT (circuit test), FCT (function test), aging test, temperature and humidity test, drop test, etc.
The above four points are the main issues that we must pay attention to in PCBA processing. These are some of the main contents that PCB assembly house SYS Technology shares with you today.