Issue link: https://iconnect007.uberflip.com/i/1527952
36 PCB007 MAGAZINE I OCTOBER 2024 chemistries, adhesion promotors (coupling agents), and specialty catalysts to optimize etching geometries, as well as specialty cop- per "trench/via" plating electrolytes. Uyemura has worked in partnership with MEC etchants to establish a portfolio of commercial products specifically for this application. Will this become more mainstream in the next decade? Nearly all the major PWB manufacturers are embracing the technologies discussed here in the next three to five years for these reasons: • Numerous U.S. companies have already established advanced capability for EPIG, EPAG, DIG, mSAP and, to a lesser degree, SAP. In addition, final finish contract plat- ers are forging ahead toward this capabil- ity as a means to qualify new processes and customers. • ese capabilities already exist overseas; they are proven, installed (even auto- mated), and can easily be benchmarked for smooth technology transfer. • As a specialty chemical company, we rou- tinely participate in equipment design reviews, so we see the majority of new equipment orders incorporating the advanced technologies we've discussed into their equipment specifications and purchases. • Electrical design engineers continually expand their high RF thresholds above 40 GHz. is is where nickel-free final fin- ishes begin to deliver unique performance advantages. e PWB roadmap for HDI, UHDI, and IC substrates will initially use an mSAP pro- cess strategy for advanced fine-pitch circuit designs, prompting a partial shi from ENIG/ ENEPIG to EPIG/EPAG for high frequency designs. Once PWB manufacturers are com- fortable with modified SAP (mSAP), the move to full semi-additive SAP will occur quickly. e timing for each company will depend on their respective competitive ambitions, accept- able yield thresholds, and customer require- ments. e basic schematic structure for SAP is shown in Figure 10. PCB007 Rich DePoto is a chemical engineer and business development manager at Uyemura International, where he works with OEMs and PWB fabricators on advanced final finish strategies for HDI and IC substrates. Figure 10: Basic schematic of SAP process and SAP via formation.