We have been working with a new surface mount line for the past year and are happy with the different pieces of equipment. We process many printed wiring assemblies some of which have 25 mil flatpacks and quadpacks throughout the board. We realize that fine pitch is not as forgiving as 50 mil pitch and through hole technology, especially when the assembly is fully automated. Our challenge is that we produce a large mix of different assemblies, each at low volume, which we must process through the same surface mount line (typical batch size 10-25 boards). This does not help when trying to stabilize a process. One of our biggest issues is coplanarity. In most cases we do not have the luxury of receiving these parts preformed and, therefore, must form them internally. The handling does not help. We are evaluating all factors which have an effect on solder yields in an effort to optimize this assembly line. We are interested in benchmarking with other companies in the industry. My first question is: What is the typical defect rate from a surface mount assembly line, when fine pitch components are involved, considering the narrowness of the process window? And my next two questions are: What coplanarity reqirement do you impose? For those doing their own component lead forming, what procedures do you use to assure meeting this coplanarity requirement? Rosaura Corral-Perez [log in to unmask] *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************