1. PCB circuit board manufacturing
Upon receiving the PCBA order, the first step is to analyze the Gerber file, paying close attention to the relationship between the PCB hole spacing and the board’s load-bearing capacity. It’s crucial to avoid any bending or breakage, and to consider essential factors such as high-frequency signal interference and impedance during the wiring design.
2. Procurement and inspection of components
1. The procurement of components necessitates strict channel control, ensuring that they are sourced exclusively from reputable large traders and original manufacturers, with a firm commitment to avoiding second-hand and counterfeit materials. Additionally, a dedicated inspection station for incoming materials is established, rigorously examining the following aspects to confirm that the components are fault-free.
2. PCB: Conduct temperature tests on the reflow soldering furnace, ensuring no flying leads, checking for blocked vias or ink leakage, and verifying the flatness of the board surface, among other factors.
3. IC: Confirm that the silk screen fully matches the BOM, while maintaining stable temperature and humidity levels.
4. Other common materials: Inspect the silk screen, appearance, and perform power-on measurements, with inspection items executed through random sampling at a typical rate of 1-3%.
5. SMT patch processing involves crucial control over solder paste printing and reflow oven temperatures. Utilizing high-quality laser stencils that meet process specifications is vital. Depending on PCB requirements, certain steel mesh holes may need adjustments, including enlargements or U-shaped modifications. The control of furnace temperature and speed during reflow soldering is critical for solder paste infiltration and overall soldering reliability, adhering to standard SOP guidelines. Additionally, strict implementation of AOI testing is essential to reduce defects from human error.
6. DIP plug-in processing highlights the importance of mold design for wave soldering. Optimizing molds to enhance the likelihood of successful products post-furnace is a process that PE engineers must continually refine and learn from experience.
7. For program firing, it is advisable to recommend that customers incorporate test points on the PCB during the DFM report. This allows for testing the PCB and PCBA circuit continuity after all components have been soldered. If feasible, customers can be asked to provide a program, which can be loaded into the main control IC using a burner, enabling a more intuitive evaluation of functional changes resulting from various touch actions and assessing the overall completeness of the PCBA’s functionality.
8. Regarding PCBA board testing, orders that require testing should focus on key content such as ICT, FCT, aging tests, temperature and humidity assessments, and drop tests. These procedures can be executed in accordance with the customer’s test plan and documented reporting data.
