Ravinder, You might consider a material from Semblant called SPF. It is a material that is vapor deposited and was originally developed as a board surface finish. It works well against harsh environments and has the "potential" for replacing solder mask in sensitive RF applications. The stuff only goes on about 40 nm thick. Hillman and I did an evaluation of this material as a board surface finish a few years back and Semblant has our report, which is available. Read through it all as the material has a few "quirks". We evaluated the material between 1 and 9 Ghz and found no significant effect on signal integrity. Semblant has offices in Chandler, Arizona. 480.722.1419 Doug Pauls From: <[log in to unmask]> To: <[log in to unmask]> Date: 07/23/2012 06:21 PM Subject: [TN] Alternative to Solder Mask for high-speed interconnects Sent by: TechNet <[log in to unmask]> Hi Experts, I am looking at the alternatives to Solder Mask for surface high-speed interconnects, as solder mask causes impedance discontinuity. I would like to use OSP process instead of solder mask, but I have been told that OSP does not protect Copper in harsh environment. I will appreciate if you can suggest some other alternatives. Thanks. Regards Ravinder Ajmani HGST, a Western Digital company [log in to unmask] 5601 Great Oaks Pkwy. San Jose, CA 95119-1003 www.hgst.com ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________