Richard Guess chatting with a baseball bat is needed, although I don't understand why the problem has appeared so long after manufacture. Brian Richard Tilbrook wrote: > Hi Technetters, I'm back again, two months (has it been that long???) into Y2K. > > My problem is on a subject about which I know little, and I write to you on behalf > of a friend upon whose project the following has manifested itself. > > We have a line upon which we manufacture simple through-hole PCBs. We are using > externally supplied multi-layer boards with nothing high-density or high tech about > them. They come in looking nice and well tinned. For about six months they have > been flowing OK, with only one problem - a large ground plane caused a few problems > in one area for a little while and we had to re-adjust the profile on the flow > machine (this is, I am sure, irrelevent to the problem). We like to manufacture to > a very high standard, so it was concerning when some PCBs recently exhibited bare > copper in various places. We use a low tack professional masking tape to mask two > planes on the board during conformal coat - on removal, the tinning came away, > exposing bare copper! Even more seriously, at many places solder had not fully > wicked to the top of the through-hole, meaning very suspect joints. In various > places, solder had wicked away from pads, again exposing copper. > > Is it possible that we are doing something wrong without realising, or shoud we be > chatting to our board suppliers? > What do you folks feel is the problem, and what do you recommend we look at? > > Regards, > > Richard Tilbrook > Junior Engineer > > ############################################################## > TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c > ############################################################## > To subscribe/unsubscribe, send a message to [log in to unmask] with following text in > the body: > To subscribe: SUBSCRIBE TECHNET <your full name> > To unsubscribe: SIGNOFF TECHNET > ############################################################## > Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional > information. > If you need assistance - contact Keach Sasamori at [log in to unmask] or > 847-509-9700 ext.5315 > ############################################################## ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ##############################################################