半孔要求：半孔金屬無缺損，無偏孔，無殘油；

Ultra-thin CSP substrate
CSP products: board thickness (0.15-0.25mm)
Assembly method: Aluminum wire bonding
Surface treatment: Shen nickel gold (gold thickness: 0.05um, nickel thickness: 5um)
Soldering resistance requirements: black oil, black oil needs to be plugged; NPTH is not allowed to have residual oil; copper is not allowed to be exposed;
Semi-hole requirements: The semi-hole metal has no defects, no deviated holes, and no residual oil;