1. Engineering design

　　The arrangement of interlayer semi cured sheets should correspond; Multi layer core boards and semi cured sheets should use the same supplier's products; The area of the outer C/S surface graphics should be as close as possible, and independent grids can be used;

　　2. Drying the board before cutting

　　Generally, at 150 degrees Celsius for 6-10 hours, the moisture inside the board is eliminated to further solidify the resin completely and eliminate stress inside the board; Bake the board before cutting, whether it is the inner layer or both sides!

　　3. Attention should be paid to the warp and weft directions of the cured sheets before laminating multi-layer boards

　　The contraction ratio in the warp and weft directions is different. Before cutting and stacking the semi cured sheet, pay attention to distinguishing the warp and weft directions; When cutting the core board, attention should also be paid to the warp and weft directions; The general direction of the cured sheet roll is in the warp direction; The length direction of the copper clad plate is in the longitudinal direction;

　　4. Cold press the laminated thick stress relieving pressure plate and trim the burrs;

　　5. Drying plate before drilling: 150 degrees for 4 hours;

　　6. It is recommended to use chemical cleaning instead of mechanical grinding and brushing for thin plates; Special fixtures are used during electroplating to prevent bending and folding of the board

　　7. After tin spraying, cool naturally on a flat marble or steel plate to room temperature or clean with an air flotation bed after cooling;