Re: Homemade PCBs!

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Jim Lux" <jimlux-at-earthlink-dot-net> 

A layer is a surface with copper traces on it.  A two sided board would have
2 layers (top and bottom) of copper.  The original artwork would probably
have 4 or 5 layers:
silkscreen (the white printing)
solder mask (the green stuff that keeps the solder from covering everything)
the top layer of copper traces
-- the substrate (FR4, G10, XXXXP or whathaveyou)
the bottom layer of copper traces
the solder mask for the bottom

plus, you'd usually get a drill file (specifying which sizes of holes are
where on the board)

A 4 layer board would have 4 conductive layers. top/substrate/inner 1/thin
substrate/inner2/substrate/bottom Usually, the inner layers are used for
power distribution (and shielding), because it's hard to probe inner layers
for diagnosis.

There are folks making boards with 20+ layers.  mfr yield is a challenge.

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Tuesday, April 27, 2004 8:05 PM
Subject: Re: Homemade PCBs!


 > Original poster: Fucian-at-aol-dot-com
 >
 > What are all these layers for?What exactly IS a layer?
 >
 > Matt
 >
 >