Good morning everyone! We are currently investigating a failure mode that has happened on a few of our customer's assemblies. The problem is as follows (a little background): We have three confirmed occurrences in which a through-hole clinched resistor lead has shorted out with a non-common conductor on the "solder side" of the board. All the conductors are coated with soldermask, however, after about four (4) months in the field (in which the unit had been working properly) the resistor lead had penetrated or pierced through the soldermask and "shorted" out with the adjacent conductor. The cause of the penetration is unknown at this time. We gently pulled the resistor lead slightly away from the adjacent conductor and the unit began working properly again (short was gone). We inspected the soldermask at 40X but did not see any copper exposure. IPC-A-610C (Section 5.2.7.2) states that "The lead is clinched toward an electrically non-common conductor, violating minimum electrical clearance" is a defect (all three classes). Our Auto-insertion machines are set up for a 45 degree angle clinch. (However, in these cases the clinch was below 45 degrees...so it did appear the clinch was much tighter to the board than we would like) So....The issue we have are the following: The design of the board is such that the clinched resistor lead will always overlap the adjacent non-common conductor. Our detection for this condition has always been ICT and Functional Testing (which it will detect if the condition exists immediately). But unfortunately the failure did not occur until the unit was in the field for awhile. Has anyone else ever experienced this problem? If so, what steps were taken to resolve it? How was is verified? Did you have to rely on visual inspection of the clinch over soldermask? Help!!!! Thanks ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8d ############################################################## 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 ##############################################################