SEMI-ADDITIVE PROCESS for Low Loss Buildup Material in High-Frequency Signal Transmission Substrates

摘要

The novel SAP process combines innovative etching, conditioning and direct metallization techniques. It contains similar processes as traditional SAP, which makes it adaptable to existing equipment sets. Moreover, the processed dielectric surface can maintain low surface roughness, and supports superior dielectric-plating adhesion through chemical bonding. The novel SAP has been successfully applied to epoxy or cyanate-ester type dielectric materials (Material A) and achieved very low desmear roughness (Ra= 80±18nm) and excellent adhesion (658±18gf/cm). Considering the general lower limit for the dielectric-plating adhesion on Material A (550 gf/cm), the application of the novel SAP is a typical Six-Sigma capable process both in short-term (Cpk = 2.51) and long-term (Ppk = 2.06). In addition, novel SAP also opens good potential on other dielectric materials widely used in the current SAP market.