Homebrew PCBs

----- Original Message ----- 
From: "Mike Oyama" <mikesb0x0fm4il2@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Thursday, April 23, 2009 2:59 AM
Subject: Re: [Homebrew_PCBs] Re: recommended thickness for boards



>
> Oh, and by the way, the terms FR-4 and CEM refer to the substrate that the
> boards are made of, and not how many sides are clad with copper. FR-4 is a
> UL flame retardant specification, and will usually refer to a board that 
> is
> Epoxy Resin bonded fiberglass. CEM boards are often a Synthetic Resin 
> bonded
> paper. So be careful when choosing your boards, and don't just assume that
> all FR-4 Boards are double clad.

CEM isn't SRBP! It's a composite of thin fibreglass and compressed paper.

Leon