Homebrew PCBs

----- Original Message ----- 
From: "lcdpublishing" <lcdpublishing@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Friday, August 25, 2006 2:46 PM
Subject: [Homebrew_PCBs] How are multi-layer PCBs made?


> Hi guys,
>
> Last night I was thinking about 3 and 4 layer PCBS and can't seem to
> figure out how they do them.
>
> Single sided - easy, we all do that.
> Double sided - easy, we do that as well with some alignment issues.
>
> But once you get beyond that, I realize a different manufacturing
> process has to be done to get the layers.  How do they do it?

They are built up from thin prepregs - fibreglass and uncured resin - and 
cores - thin double-sided copper/fibreglass laminate. Outermost layers are 
prepreg on one side and copper on the other. The cores are etched in the 
usual way, the layers of prepregs and cores are stacked up and the whole 
thing is put in a heated press which cures the resin and bonds everything 
together.

Leon