表面處理：沉金（金厚：0.02um，鎳厚：4um）

導通孔填充要求：導通孔表面履油平整，無明顯凹痕

Ultra-thin silicon wheat MEMS substrate

Assembly method: Gold wire package + SMT welding

Surface treatment: Immersion gold (gold thickness: 0.02um, nickel thickness: 4um)

Via hole filling requirements: the surface of the via hole is smooth, without obvious dents