Moisture sensitive 4017's?

Discussion in 'General Electronics Chat' started by magnet18, May 16, 2011.

  1. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    Alright, I recently got a bunch of parts in the mail, and I thought I got some normal 4017's, just the cheapest ones I could find. 11MHz, 6-20V, all normal, right?
    Well, when they showed up, they were in a solid silver bag, which I haven't opened yet, but on it it says they have an out of bag life of one year and may require baking before mounting and etcetera.
    Can I still use these like normal, or should I order new ones?
    And what exactly are they?:confused:
     
  2. #12

    Expert

    Nov 30, 2010
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    I never heard of that. Perhaps they are really potato chips that would get stale in a year and need to be baked a bit.

    Open the bag and see what you have. Some places do labels badly, like sending me 3 amp fuses marked, "static sensitive".
     
  3. Wendy

    Moderator

    Mar 24, 2008
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    It does sound a bit bogus. Old parts can be hard to solder, but not in the time frame you are talking about. It takes years, and basically the tin oxidizes and solder doesn't stick well anymore (think of it as rust). Solder flux can help if it is a problem.

    Your specs sounded way off, so I looked up a datasheet. CMOS has wide voltage specs (3V - 15V)...

    http://www.national.com/ds/CD/CD4017BC.pdf
     
  4. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    My bad, it has an input of 3-20V
    part number HCF4017BEY, manufactured by stmicro
    I opened it up and it had a humidity meter and there were like 5 packets of silicon dioxide in it(that stuff that says "do not eat").

    datasheet says 10mhz, the package I'm holding says 11...
     
  5. Wendy

    Moderator

    Mar 24, 2008
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    The one I posted says 5Mhz (I think). What does your's say the maximum current out is? I'm used to 6.8ma for the spec.

    You can't go wrong with too many gel packs.
     
  6. t06afre

    AAC Fanatic!

    May 11, 2009
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    Oxidation my very well be a problem in an automated soldering process. but for a hobbyist using manual soldering. Not very likely , but the components may be somewhat solder to solder if the pins are very oxidated. This is here the solder flux come in. Solder flux is a chemical cleaning agent that facilitates soldering, removing oxidation from the metals to be joined
     
  7. SgtWookie

    Expert

    Jul 17, 2007
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    Believe it or not, it's due to the plastic packaging absorbing some moisture over time, and during oven reflow soldering, the package temp can get hot enough to boil water. If there is moisture absorbed in the plastic and it boils, it will rupture the IC package.

    This kind of thing really isn't a concern for hobbyists. In a production house, IC's that had been around too long would either be put on the surplus market, or they would have to be baked in a vacuum oven to draw the moisture out prior to board assembly. Otherwise, the completed boards could have an unacceptably high failure rate.
     
    magnet18 and #12 like this.
  8. tom66

    Senior Member

    May 9, 2009
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    It's not bogus at all. Moisture inside the casing can cause microfractures which can damage the IC especially during soldering or reflow. I have several other parts with the same markings.
     
  9. #12

    Expert

    Nov 30, 2010
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    Thanks, Wookie. I learn something new every day.
     
  10. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    10mA!!
    Part page
    Datasheet

    I got mine for 20 something cents a piece :cool:
    They were on sale.
     
  11. Kingsparks

    Member

    May 17, 2011
    118
    5
    Hi.
    I know this is an old thread and I'm new but couldn't help it, I broke up over the "static sensitive" 3A fuses. I got one almost as good, a bag of sockets, about 50 various types, 4, 6, 8, 14 etc DIP sockets marked, yep, "static sensitive" and in a real nice anti-static bag. No joke, er, maybe joke after all.
    Roland
     
  12. #12

    Expert

    Nov 30, 2010
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    @Kingsparks, 25 hours isn't considered old here.

    ps, thanks for helping me. I try to crack this place up, but emotions don't travel well through wires.
     
  13. magnet18

    Thread Starter Senior Member

    Dec 22, 2010
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    I've had the same thing happen as well. :p
    And I love when TVS diodes (they are used to stop lightning for petes sake) show up in static bags :rolleyes:

    And I just posted a couple hours ago in this thread... what forum did you come from? ;)
     
  14. Audioguru

    New Member

    Dec 20, 2007
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    I have heard about LEDs having a warning to bake them before soldering them if they were in a humid environment. So I think your HEF4017 ICs and the 3A fuses were simply packaged in the wrong bag that had the warning for LEDs.

    The typical output current of a CD4xxxxB IC is 6.8mA when it has a 15V supply and a voltage across its output transistor of only 1.5V. If the supply is 15V and the output transistor has 13V across it because it is driving a 2V red LED then the current is typically 29mA and the output transistor will melt with a power dissipation of 13V x 29mA= 377mW unless it is run through 10 steps very quickly.
     
  15. nbw

    Member

    May 8, 2011
    36
    10
    Does the datasheet specify a humidity rating at all, other with min/max temps? I remember in Singapore we had problems with humidity affecting quite simple electronics circuitry.
     
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