glass diodes

Discussion in 'General Electronics Chat' started by DexterMccoy, Mar 18, 2014.

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  1. DexterMccoy

    Thread Starter New Member

    Feb 19, 2014
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    what does glass diodes do different than black plastic package?

    Some glass diodes are germanium, why are they glass?

    what is the advantage of glass and what is the disadvantage?
     
  2. magnet18

    Senior Member

    Dec 22, 2010
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    it's just a different packaging choice, the pros and cons are mostly mechanical

    for example, in a vacuum system, glass diodes are preferred because they do not outgass like a plastic would

    on the other hand, glass is much more fragile
     
  3. DexterMccoy

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    Feb 19, 2014
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    So glass last longer?

    How about cold and hot temps? does glass last better and longer?
     
  4. magnet18

    Senior Member

    Dec 22, 2010
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    I wouldn't say either lasts longer
    either could be designed to last centuries of constant operation

    there is no "better and longer" for all circumstances, it's a matter of how they are mechanically engineered for the expected environments (in the case of your question, temperature)
     
  5. DexterMccoy

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    So glass packages are better with temperature?
     
  6. crutschow

    Expert

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    Glass is also essentially perfectly hermetic whereas plastic is not, so glass is preferred in high humidity or wet environments. That's why plastic packages are seldom used in Military or other critical environments.
     
  7. KMoffett

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    Dec 19, 2007
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    Glass diodes are sensitive to ambient light. Black plastic diodes are not.

    Ken
     
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  8. DexterMccoy

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    What do you mean by hermetic? the advantage is?
     
  9. KMoffett

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    A hermetic seal is a fluid-tight glass-to-metal bond. Gasses and liquids cannot penetrate the diode and contaminate it.

    Ken
     
  10. crutschow

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    Look up the meaning of hermetic if you don't know. :rolleyes:
     
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  11. GopherT

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    What do you mean, "look up the meaning"?:rolleyes:
     
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  12. ErnieM

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  13. crutschow

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    You've never heard of Google or a language dictionary? :confused: Are you related to Dexter?
     
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