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
---------------------------------------------------------------------------------
|
