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: <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