Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!elroy.jpl.nasa.gov!thyme!kaleb
From: kaleb@thyme.jpl.nasa.gov (Kaleb Keithley	)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: What is a "6 layer" motherboard?
Message-ID: <1990Nov1.182438.8976@thyme.jpl.nasa.gov>
Date: 1 Nov 90 18:24:38 GMT
References: <1990Nov1.171839.13283@magnus.ircc.ohio-state.edu>
Organization: Jet Propulsion Laboratory, Pasadena, CA
Lines: 18

In article <1990Nov1.171839.13283@magnus.ircc.ohio-state.edu> smsmith@hpuxa.ircc.ohio-state.edu (S. Smith) writes:
>I've seen "6 layer" motherboards advertised, and the company I might
>buy my computer from has one of these.  What does "6 layer" mean?

Well, if a one-layer board has copper traces on one side, and a two-layer 
board has copper traces on both sides, then a n-layer board may be made
by laminating n-2 very thin one-layer boards with a very thin two-layer 
board.  It's just another way of cramming more circuitry (traces, not
chips) into a fixed size space.  Most 486 boards, and I expect a lot
of 386 boards are 6-layer boards.  A lot of the clone-XT motherboards
were/are available in either 2 or 4-layer boards, and I'd guess that all the
286 motherboards are 4-layer boards.

-- 
Kaleb Keithley                      Jet Propulsion Labs
kaleb@thyme.jpl.nasa.gov

"...we need a bigger boat"