Re: A note on PC boards, double and single sided.


David Holland
 

Work in IT. You'll do all 3....

Careful, don't get the ITIL on your shoes.....

On Wed, Jan 6, 2021 at 12:29 PM Leon Robinson <leon-robinson@sbcglobal.net>
wrote:


Brad,
I have had horses for over 40 years and I don't remember going around and
smelling warm horse s*hit, have stepped in some and shoveled a lot.

Leon Robinson K5JLR

-------- Original message --------
From: Brad Thompson <brad.thompsonaa1ip@gmail.com>
Date: 01/05/2021 9:25 PM (GMT-06:00)
To: TekScopes@groups.io
Subject: Re: [TekScopes] A note on PC boards, double and single sided.

Harvey White wrote on 1/5/2021 8:55 PM:

Printed circuit boards are generally made with one of two materials
(there are others), either a paper epoxy (FR-3) or a fiberglass epoxy
(FR-4). There are others, but these are most common.

Paper epoxy (FR-3) has a lower temperature tolerance, is not as
mechanically stable, can be burnt easily, and is constructed of paper
and epoxy holding it together. You see it in a lot of commercial
(expensive or not...) equipment. It is mostly brown...
Hello--
Older imported electronics used a phenolic-based laminate-- typically
medium to dark brown
and liable to losing its traces when the repairer applied too much heat.
Oh, and when overheated
it smelled like warm horse s*it.

73--

Brad AA1IP










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