High-Speed Signal Transmission Rigid Substrate Fabricated by Silver-Seed Semi Additive Process

Cu signal transmission line with a flat and smooth surface was fabricated on a low dielectric rigid substrate by using Silver-seed Semi Additive Process (Silver-seed SAP). The transmission loss evaluation of strip line manufactured by Silver-seed SAP was conducted and compared with the samples fabricated by conventional process. It was confirmed that combination of Silver-seed SAP and the chemical adhesion treatment without roughening can achieve the fabrication of transmission line having four-sided smooth and flat surfaces. This surface characteristic can reduce conductor loss, and therefore can reduce transmission loss compared to the transmission lines fabricated by the conventional modified SAP and subtractive process.