The production of steel mesh is very important to the SMT chip processing technology. It will directly determine whether the tin on each pad is uniform and full, which will affect the soldering reliability of SMT components after reflow soldering. Generally speaking, the development of steel mesh requires careful analysis of the characteristics of each PCB. For some high-precision and quality-required circuit boards, laser steel mesh must be used, and SMT patch engineers are required to conduct a meeting to discuss and confirm the process flow. Adjust the aperture of the opening to ensure the tinning effect.
When making SMT patch steel mesh, it is generally necessary to pay attention to: 1.ME requires the supplier to make steel mesh according to the relevant documents and materials provided by the engineering department. 2. The frame size requirements of the steel mesh (550MM*650MM 370MM*470MM, etc., mainly based on the structure of the printing press and product specifications). 3. The label on the steel mesh (product model, thickness, production date, etc.). 4. The thickness of the steel mesh (generally 0.18MM-0.2MMM for squeegee, 0.1MM-0.15MM for tinning). 5. The opening method and size of the steel mesh (the anti-tin ball is generally V-shaped, U-shaped, concave, etc., depending on the type of each component.). 6. The direction of the board and the placement machine should be unified.
SMT steel mesh acceptance notes:
1. Check whether the method and size of the steel mesh opening meet the requirements
2. Check whether the thickness of the steel mesh meets the product requirements. 3. Check whether the frame size of the steel mesh is correct. 4. Check whether the marking of the steel mesh is complete. 5. Check whether the flatness of the steel mesh is level. 6. Check whether the tension of the steel mesh is OK. 7. Check whether the position and quantity of the steel mesh opening are consistent with the GERBER file. The production of steel mesh is an important part of the quality control of the entire SMT processing process. Engineers must pay full attention to it. Customers should not deliberately reduce costs, resulting in poor tin application after using the steel mesh and affecting the entire production schedule.