(1) The inner circuit board shall be baked and kept dry before laminating and pressing.

Strictly control the process procedures before and after pressing to ensure that the process environment and process parameters meet the technical requirements.

(2) Check the Tg of the pressed multilayer board, or check the temperature record of the pressing process.

Bake the pressed semi-finished products at 140 ℃ for 2-6 hours, and continue to cure.

(3) Strictly control the process parameters of oxidation tank and cleaning tank in the blackening production line and strengthen the inspection of the surface quality of the board.

Try double-sided copper foil (DTFoil).

(4) Cleaning management shall be strengthened in operation area and storage area.

Reduce the frequency of manual handling and continuous plate taking.

During stacking operation, various loose materials shall be covered to prevent pollution.

When the tool pin must be lubricated and released, it shall be separated from the stacking operation area, not within the stacking operation area.

(5) Properly increase the pressure intensity of pressing.

Properly slow down the temperature rise rate and increase the glue flow time, or add more kraft paper to ease the temperature rise curve.

Replace the prepreg with high gel flow or long gel time.

Check whether the steel plate surface is flat and free from defects.