Mail*Link(r) SMTP FWD>>DES/FAB- hole wall thic Susan and all, I apologize, I goofed when I didn't pre-read/edit my previous response to Susan's inquiry. In the table of sheet resistances, the last one was in error. The error for the 190 micrometer Cu thickness was the 5 mils Cu should have been 2 mils Cu which was the mentioned PTH Cu plating thickness Susan mentioned, and is corrected in the complete table below. 25 micrometer [1 millinch] ~680 microhms/sq 35 micrometer [1 oz/sqft Cu] ~485 microhms/sq 50 micrometer [2 millinch] ~340 microhms/sq 70 micrometer [2 oz/sqft Cu] ~240 microhms/sq 140 micrometer [4 oz/sqft Cu] ~120 microhms/sq 190 micrometer [4 oz/sqft + 2 mils Cu] ~90 microhms/sq Ralph Hersey e-mail: [log in to unmask]