How long would you expect a digital watch to last?

Discussion in 'General Electronics Chat' started by epsilonjon, Jun 16, 2012.

  1. epsilonjon

    Thread Starter Member

    Feb 15, 2011
    65
    1
    Hello.

    I like collecting watches, and in particular have a couple of old Casio G-Shocks from the 1980s. It's very impressive to me that they still work as well today as they did brand new!! This got me thinking, how long will a good quality digital watch last before it dies of "old age"? Which are the components that typically limit the lifetime (i'm talking the electronic parts, not the strap, bezel, etc which can usually be replaced easily)? I would have thought the LCD would have faded/died, but they still look very sharp, even after nearly 30 years! Has anyone here ever opened up an old digital watch and done tests to see how the parts have degraded?

    Thanks :)

    P.S. I wasn't sure whether to put this here or in the "off-topic" section, so apologies if I decided wrong.
     
  2. HommerSimpson

    New Member

    Jun 9, 2011
    14
    0
    ALL digital watches lasted about 1 - 24 hrs On my mom.. seriously..she could not wear one.. had a wind up.. every digital watch died .. but then she did have High Iron.. hemoglomotosis lol < sp wrong
     
  3. KJ6EAD

    Senior Member

    Apr 30, 2011
    1,425
    363
    The long term failure components are the rubber seals on the back and buttons and the zebra connector for the display.
     
  4. Bernard

    AAC Fanatic!

    Aug 7, 2008
    4,172
    397
    Sadly ,my TI digital watch died this year, bought in Witcha KS about 1958. The tritium back light was just bairly visible in a real dark room, half life 11 years, so about 6 half lives. No autopsy preformed.
     
  5. Wendy

    Moderator

    Mar 24, 2008
    20,766
    2,536
    There are several failure mechanisms that are not well documented. Interestingly (to me) the more expensive (read that military electronics) have built in failure mechanisms that cheaper electronics avoid.

    This is because gold wire is used to bond to aluminum chips. We are talking raw chip die here. Some chip dies use gold, and is not a problem. When a gold wire is attached to a aluminum pad in a process called bonding the gold slowly absorbs the aluminum like a sponge, so in 20+ years or so the aluminum pad no longer touches the gold, there is a microscopic open around the gold ball on the pad. This process is called Kerkove voiding, or something very close.

    Wire bond processes can be hard to find. Here is a example I found...

    http://www.majelac.com/Wirebonding.html?gclid=CJ_1hr-H1LACFcEDtgodBHO0zg
     
    Last edited: Jun 16, 2012
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