Thanks Gary. Although "tenting" refers to covering the pad (in our case via pad) we are only allowing encroachment of solder mask to .002' of the finished drill hole. Does IPC have guidelines for this methodology? And, is this a cost addeder as well? (we are questioning our board suppliers right now) Thanks, Ray Gary Ferrari <[log in to unmask]> Sent by: TechNet <[log in to unmask]> 07/03/2002 09:54 AM Please respond to "TechNet E-Mail Forum."; Please respond to Ipcgary To: [log in to unmask] cc: Subject: Re: [TN] Guidelines for tenting via's Ray, You can find information about tenting vias in IPC-2221 Generic Standard on Printed Board Design, section 4.5.1 Solder Resist Coatings. It does indicate that the maximum size for tenting is 1.0 mm for Class 1 and 2 and 0.65 mm for Class 3 equipment. The tenting acceptability for larger sizes should be discussed between user and supplier. Regards, Gary