First, the SMT steel mesh in the production process attention is mainly reflected in:

1. SMT steel mesh opening principle;

2. Acceptance of SMT steel mesh;

3. Printing format requirements for SMT steel mesh

Second, SMT steel mesh opening principle

1. For the three times of CHIP type components, increase the area by 10-15 [%], keep the internal distance unchanged, and then modify according to lead requirements.

2, IC components (including the plug) length plus 0.1-0.20mm, the width of the lead required to modify, can be appropriately widened

3. Exclusion and discharge type components, the length is 0.1mm outward. Width can be modified according to lead requirements

Third, the acceptance of SMT steel mesh

1. Steel mesh tension 35≤F≤50(N/cm) Tension error: F is less than or equal to 8 (N/cm)

2, the appearance of the steel mesh: no scratch marks on the mesh surface, no bump

3. Before the new steel mesh is produced, the steel mesh is correctly installed on the printing machine, and 2 - 5 plates are tested for printing to confirm the printing effect.

4. After the trial production is passed, the production time is recorded in the relevant documents of the steel mesh management.

Fourth, the printing format requirements of SMT steel mesh

1. When the board is in a net, the position of the opening graphic is required to be centered.

2. When two different PCB boards are opened on the same steel mesh, the spacing between the two boards is required to be 30mm.