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IC Pins too wide — Parallax Forums

IC Pins too wide

Eric AdamsEric Adams Posts: 11
edited 2006-06-14 04:50 in General Discussion
Just a quickie for all you pro's.· The width of all new·IC pins are wider than the spacing when a pc board is made.· Normally this just requires a little friendly persuasion and patience to fit them in.· However my patience is running out this time as I have to mount 900 IC's.· Is there a tool or something that compresses the pins on new IC's and makes easy the alignment and insertion on a PC board?

Thanks in advance

Comments

  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-06-13 02:06
    Eric,

    ·· Which ICs do you refer to?· I have not seen any issue with the new SX chips, but if that's what you refer to please let us know which one it is that's·may be·having the problem so we can look into it further.· Thanks.


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    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2006-06-13 02:26
    I think he means DIP-ICs.· It's been that/this way for a long time, but when they come in rails brand-new, the leads are slightly splayed out away from the body so that they're about 0.35in across.· So, you have to form them in order to place them in sockets, etc. (0.3in. across).
  • Eric AdamsEric Adams Posts: 11
    edited 2006-06-13 04:59
    Yes I am basically referring to through hole dip's.· When they come in the antistatic sleves they measure almost .38" wide accross the botton of the pins.·The pads on the PC board is .3". ·I have not noticed this on the SX chips as much however they are the only ones I use a socket for.· The sockets are double wipe and the Sx chips fit in with a little persuasion.

    I cannot understand why there isn.t some type tool that I could grab the IC with and by squeezing it get my .3" so it would just be aligned perfectly.

    Eric
  • Ken GraceyKen Gracey Posts: 7,403
    edited 2006-06-13 05:12
    Hey Eric,

    I could imagine modifying a pair of needlenose pliers to have a right-angle on the end of both surfaces, so that both sides of the 300 mil DIP could be pressed inward the same amount. Add some type of depth stop as well.·Just a thought, though there must be some off-the-shelf tool that would do the trick.

    Ken Gracey
    Parallax, Inc.
  • Guenther DaubachGuenther Daubach Posts: 1,321
    edited 2006-06-13 08:26
    Hey Eric,

    I'm using the IC Pin Straightener avalable from Digikey, part-# A998-N. There are also various insertion tools available at Digikey but unfortunately, I could not find one that fits the SX 28 so far.

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    Greetings from Germany,

    G
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2006-06-13 13:45
    I simply use a plastic cutting board as a surface and gently roll one side and then the other until they fit.
    For myself, needlenose are a disaster as I tend to over do some.

    With 900, you might be able to use the cutting board; but the pin straightener is best.
    I don't think it is a new problem [noparse][[/noparse]circa 1970s, I had the same].
    That is why Guenther has an IC Pin Straightener [noparse][[/noparse]they are a bit expensive].

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    "If you want more fiber, eat the package.· Not enough?· Eat the manual."········
    ···················· Tropical regards,····· G. Herzog [noparse][[/noparse]·黃鶴 ]·in Taiwan
  • Guenther DaubachGuenther Daubach Posts: 1,321
    edited 2006-06-13 19:30
    Hey,

    c'mon - before manually adjusting the pins of 900 chips using a cutting board, the pin straightener adds costs of about 0.1 cent per chip, so it's peanuts.

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    Greetings from Germany,

    G
  • pjvpjv Posts: 1,903
    edited 2006-06-14 01:35
    Hi All;

    The reason the pins are splayed is because that way the automated machinery can grab them with just friction.

    Secondly, when they are installed into the PCB, they will try to spring back (provided the pins have not yielded), and prevent the ICs from falling out of the board while it is being handled as others are inserted. It would be a real mess without this "board hugging" feature as our automated dip shooter fires as fast as one chip per couple of seconds!

    As far as I can recall, they have been manufactured that way since the 1970's.

    There are standard manual IC grabbers (DIP) avaialable to assist the manual assembly process. As a DIP is interted into it, the pins are squeezed to the correct 0.3 inch width. Probably $10 to $20.

    Cheers,

    Peter (pjv)
  • Eric AdamsEric Adams Posts: 11
    edited 2006-06-14 04:50
    Thanks to all you pro's. Guenther gave me the tool name to use and others their ways they did it. I can also see why these autonatic machines need the leads sprung. I have ordered a pin straightner for this task and I will see what it does. Again Thanks for your input
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