Matthew, I have to agree with you. When you get down to board sizes like 2.500" x 1.500", and smaller, you just can't spare the space. If your manufacturing processes are sound, you can definitely get closer to the edge. I've gone as close as 0.050" without significant failure rates on products which had production quantities in the range of 2000-4000 per week. And, we designers were very much driven by failure rate concerns at that company. Jay DeKing EMA Mid-Atlantic, Inc. (716)334-2970 voice (716)334-3481 fax [log in to unmask] -----Original Message----- From: Matthew Park [SMTP:[log in to unmask]] Sent: Friday, December 19, 1997 3:59 PM To: [log in to unmask] Subject: Re: [TN] Design:Component pad -Reply Steve, I keep hearing some vendors of ceramic SMT capacitor mfg's say things like keeping a min. space requirement you just mentioned. In reality, I see no product follows the min space req recommended by cap mfg's. It is a waste of board real estate. And cap mfg's are not familiar with SMT manufacturing process, and they are not sure about the quality of ceramic cap's that they manufacture. I had few experiences of cracked ceramic cap's from mechanical stress caused by Pick'n Place machine nozzles and chucks, or sometimes by thermal shocks. In these instances, the problem was solved by replacing with a diff brand of cap's or a diff batch. Rarely did I have the problem from breaking boards away from panel. 5mm (0.2") clearance gap recommendation by cap mfg's is not practical in board design & assembly and I say it is absurd. Just my opinion. Matthew >>> Steve Collins <[log in to unmask]> December 19, 1997 9:24 am >>> If the board is scored and uses SM Capacitors check with your component vendor. We have had two vendors here in house in the last couple of months and both say that the recommended spacing is .200 from scored edges and the same for the area around the tabs on routed boards. Like you I agree that this is way too much real estate to lose, but this type of component is are very susceptible to cracking from thermal stress and mechanical stresses more so than SM Resistors. Steve Collins PCB Design Supervisor Antec Network Technologies ---------- > From: JoAnn Amerson <[log in to unmask]> > To: [log in to unmask] > Subject: Re: [TN] Design:Component pad > Date: Friday, December 19, 1997 3:07 AM > > > Could someone be kind enough to tell me > > what is the minimum distance between the > > edge of pcb and the end of pad on a > > panelized board ? IPC -std ? > > > > We do not use IPC standards here but we use .040" from the board edge if it's > scored and .020" if it's routed. I personally feel that's waaaaay too much > real estate to throw away but it wasn't my decision. Anyone care to help me > get this changed? All help is appreciated. > > Happy Holidays! *<():-)> > > JoAnn L. Amerson > Design Librarian > Red Lion Controls, Inc. > E-mail: [log in to unmask] > Voice: (717) 767-6961 ext 6308 > > ############################################################## > 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 > ############################################################## ############################################################## 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 ############################################################## ############################################################## 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 ############################################################## ############################################################## 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 ##############################################################