> Gary Camac wrote: > > Jim > Your quoted chapter and verses bring up a question that I have been > struggling with. With todays ever shrinking lines and spaces, what is > considered the "minimum electrical spacing"? It seems to me that > different sections of a PWA could have different spacing requirements. > How is this spacing being documented so that the information can be > related to production personnel? > > Gary, Minimum electrical spacing is dictated by voltage. IPC-D-275 requires .005 for a finished assembly with 0-15V between adjacent conductors. The spacing requirements increase with voltage and whether or not the assembly is conformally coated (which has a higher dielectric constant than air). It's common for different sections of an assembly to be operating at different voltages and so have different spacing requirements. As for documenting that information for production personnel, it's not usually done, since by the time it gets into production, it's too late to fix an insufficient spacing problem. Instead, the approach is to make right by design. Michael Hiteshew Lockheed Martin Launching Systems [log in to unmask] (410) 682-1259 ################################################################ 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's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################