No, I don't see how hatching could help at all, you would just be losing the benefit of the planes coupling together well, and the impedance would be less (and probably mismatched if you don't test/calculate for it) because the trace is travelling over "gaps" in the plane. The only benefit I could see to hatching is less warpage in some cases, and maybe better bond strength for weird materials Hmmmmm... am I forgetting something? onward thru the fog, Jack -----Original Message----- From: Scott D. Shepard [SMTP:[log in to unmask]] Let's say that 4 layers is the max(I have no other choice - cost...) but EMC is still a requirement. Would hatching the pwr and gnd planes be an option that would actually help? ################################################################ DesignerCouncil 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 DesignerCouncil <your full name> To unsubscribe: SIGNOFF DesignerCouncil ################################################################ 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 ################################################################