Newsgroups: sci.electronics
Path: utzoo!henry
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: Tunnel diodes...who makes 'em these days?
Message-ID: <1991Jun5.163259.1228@zoo.toronto.edu>
Date: Wed, 5 Jun 1991 16:32:59 GMT
References: <CDHWILLI.91May28174423@exua.exua.exeter.ac.uk> <16303@life.ai.mit.edu>
Organization: U of Toronto Zoology

In article <16303@life.ai.mit.edu> tk@wheat-chex.ai.mit.edu (Tom Knight) writes:
>What makes you believe that tunnel diodes will work at 4K? I would
>guess that carrier freezeout would start being a significant effect at
>about 25K and would be near complete at 4K...

I would also predict some problems with differential thermal contraction
causing cracking of package, chip, and/or leads well before then.  Back
when IBM was working on Josephson-junction computers, they put quite a
bit of effort into the problem of building circuit assemblies that could
go from room temperature to cryogenic temperatures and back repeatedly
and remain reliable.
-- 
"We're thinking about upgrading from    | Henry Spencer @ U of Toronto Zoology
SunOS 4.1.1 to SunOS 3.5."              |  henry@zoo.toronto.edu  utzoo!henry
