I agree that a bd mfr. *can* correct for silk on pads (not just SMT but vias and other features), however, this can be costly, must be done for every lot, will vary from bd shop to bd shop, and most importantly, you may lose important info from the PCB. Your designers should inspect the layup of the silk, and exterior layers for these issues and correct them at the design level. We had problems with this until our PCB shops told us their registration requirements for silk, which we then incorporated into our database. It has become a rare occurrence since then. ---------- From: TechNet-request To: louh Cc: technet Subject: Re: FAB: Silk-screen ink on surface mount pads Date: Tuesday, May 28, 1996 8:42PM [log in to unmask] wrote: > > Recently I have seen PC boards with silk screen ink on surface mount > pads. Is any of this allowed? Looking at the PC board IPC standards, I > don't see this subject addressed. May I have some guidance? > Lou Hart 412-858-6117 > > .I am not sure about I.P.C standards but it is not recomended. Your board manufacturer should take care of this for you. Being involved in the photo dept and plotting end of board manufacturing we do not allow screening to land on any pad or surface mount area. To avoid this - using your plotter ,plot your soldermask as a negative on top of your silk screen -on the cam ,use the clear silkscreen option using appropriate mask to clear yor silk -in darkroom shoot a negative of your silkscreen and a positive of the soldermask. merge them togeather using a contact in the dark room you will be left with a positive of your silkscreen with pad and surface mount free of ink.(the old but still works way) -