Why Epoxy Encapsulation?

[gstopp at fibermux.com]

     There are a couple valid electronic reasons for epoxy encapsulation, 
     such as Dave Rossum's claim in the Emu modular catalog that it's for 
     "thermal stability". Another I can think of is mechanical vibration 
     immunity (if you think about it a transistor is like a weight at the 
     end of three skinny poles, and repeated or excessive sideways forces 
     will eventually stress the metal legs). We actually worry about these 
     things here in the manufacturing business.
     
     But - what a pain it must be to have to mix the stuff and goop it onto 
     the PC boards. You have to stock the stuff, and make molds, and pay 
     somebody to do it right - it just seems like such a drain on a 
     manufacturing process that's already low-budget in the first place. No 
     wonder you hardly ever see it.
     
     My vote is that is was territorial behaviour on behalf of these little 
     companies in an extrememly vertical marketplace, in the high-tech 
     business where trade secrets are pretty much unexplored territory and 
     patent infringement investigators need specialized expertise. Even now 
     you can rip-off a design, bring it to market, make your wad, and then 
     duck out as soon as you get a "cease and desist" order. Who cares, 
     you're rich now.
     
     - Gene


______________________________ Reply Separator _________________________________
Subject: Re: Why Epoxy Encapsulation?
Author:  Mark Pulver <mpulver at wwa.com> at ccrelayout
Date:    8/1/96 8:51 AM


At 12:55 AM 8/1/96 -0700, Sean Costello said:
     
>I was just wondering, is there any practical reason for encapsulating a 
>circuit in epoxy?
     
When ARP started doing it, the industry was pretty wild in protecting their 
sound mechanics. So, epoxy was an easy way to keep honest folks honest.
     
The thermal stability side of it all was real as well, I'm sure that other 
folks here will talk about that, but my take on it was always towards the
land of protecting company secrets (or, as you say, potential design borrowing).
     
mark
     
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 Mark Pulver/Chicagoish, IL          The home of "Son of The MIDI Wall" 
 mpulver at wwa.com                        http://shoga.wwa.com/~mpulver