Hi George, This may be barking up the wrong tree but it could be that there is some stray resist adjacent to this feature which may come from a) too narrow a gap, say less than 2 mils, or b) resist overhang on a landless hole close to the defect. a) If there is a narrow gap, the resist can sometimes be undercut and lift to lay across adjacent traces during developing. I saw this recently where a 2 mil gap existed in error between a pad and its connecting trace and was not picked up by the CAM checks because it was connected. The sliver of resist caused a fine cut across the connecting trace on a few panels. b) If a sliver of resist overhangs a landless hole, this can also break away and lay across the trace during developing which can result in a cut. Both these can cause very fine cuts. There must be a repeating cause so it is unlikely to be copper foil or process. Re-check the panel carefully after resist develop. Good luck. George Kotecki wrote:- >Technetters, > We have experienced a strange problem on a recent lot of assembled >PWB's. We are experiencing conductor cracks between a surface mount land and >its associated via. The pad is .030" wide with a .010" trace attached going >about .30" to a standard via hole. The mounting pad is a part of a quad flat >pack (32 pins). THe failure always occurs in the upper right hand pad. There >is dry film solder mask on the board. Mask clearance around the pads is .003". >Board substrate is GIN material with a constraining core of copper. What makes >this strange, is this pattern is used on other designs all fab'ed from the same >lot of material and assembled with similair parts and identical processes. > The cracking occurs at the solder fillet/mask interface. Solder >fillets >appear normal. The breaks are clean. Tooling artwork was checked and no >problems detected. The problem manifests itself when the PWB is put under >vibration albiet low levels. > Any and all help would be greatly appreciated. > > Thanks, > George Kotecki -- Paul Gould [log in to unmask] Isle of Wight,UK ############################################################## 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. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ##############################################################