This is use to be common when boards were reflowed instead of HASLed. It is usually observable on the sections, but unaided eye examination is rare. You should get some magnification to insure that the top pad is TOTALLY covered, If it is just the peripheral edge, I would deem it acceptable. My opinion is based on IPC-6012, which states in section 3.2.6, that "Coverage of platings and metallic coatings does not apply to vertical conductor edges". I could be wrong, but this seems to apply to class 3 product. This kind of discrepancy should be brought to the attention of the committee of these 2 standards. Just my three Canadian cents (2 cents US), Alain Savard, B.Sc. Chemical Process Analyst CAE Electronics Ltd. e-mail: [log in to unmask] -----Original Message----- From: Stephen R. Gregory [mailto:[log in to unmask]] Subject: [TN] Exposed copper around the periphery of anular pads.. I got called back to incoming this morning to look at a PTH board that shows exposed copper, but it's only at the side edges around the periphery of the anular pads...it's like this over the whole board. The top surfaces have tin/lead plating, but not the side edges. Top surface of pad is plated | ________V_________ __________________|__________________|__<-----Exposed copper on sides PCB Is this a defect? Looked in the IPC-A-600F on page 85, (3.3.10 Solder coating thickness) and there's a conflicting statement I think. It says; Acceptable - Class 1,2,3, "Solder coating thickness is uniform. Vertical (conductor and land) areas may not be covered. No exposed copper is evident." On one hand it says that the vertical surface may not be covered, but on the other hand it says you can't have exposed copper. If the vertical surface doesn't have to be covered, then you're gonna have exposed copper. So which is it? Also there's a statement at the bottom of the page that visual observations are made on cross sections only. I can see this with my own two eyeballs...don't need a cross section to see it. This board is for a hi-rel product by the way.... -Steve Gregory- ############################################################## 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 ##############################################################