Hi LK , I think You are dealing with microelectronics and not with PCB . On " normal " PCB there are some variations in tracks thickness ( due to plating processes ) and widthness ( due to etching process ) in terms of several microns . Corrosion on exposed copper at edges of soldered pads is completly neglible compared to mentioned above . At 14:55 26/05/98 -0400, you wrote: >Hi All, > >The issue of exposed copper, and subsequent oxidation, for an electronic >application, is very important, not only from a joint defect point of view >but, also from a trace conductor viewpoint. A typical trace and/or pad is >built with a design for a minimum conduction amount, both heat and >electrical characteristics are calculated based on a thickness of >copper. Alter the copper thickness and/or purity, by oxidation for >instance, and you alter the characteristics of the circuit, which may lead >to subsequent field failures. > >LK > >On Tue, 26 May 1998, SteveZeva wrote: > >> Hi Nicolas! >> >> As far as the exposed copper that results from an OSP process, there >> isn't an issue as far as I know. Yes the copper will oxidize, but from the >> little bit I know about metallurgy, it's my understanding is that the copper >> will be coated with a layer of oxidation, and then it slows down dramatically. >> For a illustration of that just think about some of the copper water lines in >> old houses, the copper telephone lines exposed to the elements for years and >> years...that shows that it takes quite a while for copper to deteriorate. >> >> Somebody correct me if I'm wrong about this, but the exposed copper >> problems that are defects usually have something to do with the exposed copper >> being an indicator of some other problem, not the fact that the copper itself >> is exposed. Oxidation of the copper is normally only a problem when trying to >> solder to it... >> >> C-ya, >> >> -Steve Gregory- >> >> ################################################################ >> TechNet E-Mail Forum 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://jefry.ipc.org/forum.htm) for additional information. >> For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 >> ################################################################ >> >> > >################################################################ >TechNet E-Mail Forum 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://jefry.ipc.org/forum.htm) for additional information. >For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 >################################################################ > > Edward Szpruch Eltek Ltd - Israel Tel 972 3 9395050 Fax 972 3 9309581 E-mail : [log in to unmask] ################################################################ TechNet E-Mail Forum 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://jefry.ipc.org/forum.htm) for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################