There has been much discussion here for and against silk. The 'final' word was that we needed to continue with it as an assembly aid. The $.50 per side is per process panel, which would make the per card cost variable depending on the actual card cost (recent example is $.11 per card). This was considered cheap insurance for us, as a relatively low volume, high mix mfr. Higher volumes and higher density will probably change/modify this decision. --------- From: TechNet-request To: technet Subject: RE: FAB: Silk-screen ink on surface mount pads Date: Thursday, May 30, 1996 7:30PM I totally agree with all who responded to Lou Hart's question about legend ink on surface mount pads. It should be unacceptable, and spec'ed out as such. My company standardly clips (removes) any legend ink falling within .008" of a solderable feature, due to the tolerancing required for the screen print operation. I would like to take this conversation one step further, however. Why are we still using silkscreens on our circuit boards (other than for hand assembly)? When the board shops clip silkscreen alpha-numerics from solderable features, "R"s start looking like "P"s, "B"s like "3"s, etc. Board designs are getting tighter and tighter, and there's barely any room for this stuff anymore. Folks are being charged an average of $0.50 a side for silkscreens, and now with double-sided surface mount, we're dealing with two silkscreens, or a buck a board! It's amazing how most of my customers are looking for ways to save pennies on their boards, but don't seem to mind shelling out money for silkscreens which in many cases are becoming next to impossible to read. I realize that not using silkscreens requires a culture change, but more and more of our astute customers are taking a second look at whether or not they are really needed, and some have taken the plunge and discontinued their use. I certainly don't want to disgruntle anyone (especially inspection folks!), but maybe it's time to evaluate whether silkscreens are really of any value, or simply a dinosaur from the past. Thanks for letting me throw in my $0.50! Regards, Tom Coyle Field Services Engineer HADCO Corporation