Inner layer pre treatment

Pre-treatment:

1. The inner layer pre-treatment: usually do not brushing, using micro-etching or electrolytic degreasing mode

2. Outer layer pretreatment: It usually adopts mechanical brushing plus micro-etching

Post-processing:

1. The inner is DES (development, etching, to film connection)

2 outer points, if it is a positive process, it is the same as DES

If it is a negative film process, it is only developed, then dried, then SES after secondary plating