Roger M. Stoops, C.I.D., PCB Designer Matthew Lamkin <matthew.lamkin@PROTEC-FIRE-DETECTI To: [log in to unmask] ON.PLC.UK> cc: Sent by: DesignerCouncil Subject: [DC] More Tips wanted for my first multilayer board? <[log in to unmask]> 03/12/01 10:49 AM Please respond to "DesignerCouncil E-Mail Forum."; Please respond to Matthew Lamkin Hi there again, thanks for all the tips folk's, theyre pouring in... "Input, need more input" What exactly is a power plane then? [Essentially, same as a ground plane, but with a different name. Just distributes power over a board area.]] Never having used one I'm not too sure. Is it like a ground plane? [See previous answer.] Is it used to route the power connections only, with +v signals going only to those places its supposed to and the 0v as a groundplane for the rest of that layer ? [Typically, yes. It can even be split into several or many different areas to source multiple voltages. I'm not sure what you mean 'rest of the layer', but an entire layer is typically dedicated to power, and another to ground.] I suppose that I could do that and then use the other 2 available layers for routing the signals. [Yup.] Why would the powerplane be a middle layer? if it has groundplaning/emc reduction effects wouldn't it be better nearer the outside? [Ground is typically more effective when used on the outer layers as an EMI shield. Has to do with common-mode rejection of noise and other such technical stuff. Also, power/ground planes are easier to use and create on inner layers, also make for smaller Gerber files. When power/ground planes are placed near one another (0.1-0.2mm), the design benefits from the resulting distributed capacitance, but this would not be a benefit for EMI reduction (8 layer designs work really well to get both benefits, but your management probably isn't ready for that yet...). Thanks again.... P.S. I like the wallchart etc Senthil, thanks. Hope this helps some; I'm sure you'll get even more replies... "Number five is alive!" Roger M. Stoops, C.I.D., PCB Designer --------------------------------------------------------------------------------- DesignerCouncil Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF DesignerCouncil. To set a vacation stop for delivery of DesignerCouncil send: SET DesignerCouncil NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------