Writing on the chips

Discussion in 'General Electronics Chat' started by CVMichael, May 6, 2010.

  1. CVMichael

    Thread Starter Senior Member

    Aug 3, 2007
    416
    17
    99% of the chips I have loose the paint on the chip. After I touch the chip 3-4 times, I almost cannot read the part number on them.

    Usually I take a transparent piece of tape, and tape it on top of the text on the chip, but today I am working with a small SSOP chip, and taping it is not as easy.

    What do you guys do to prevent loosing the writing on the chips ?

    This problem is getting really annoying for me.
     
  2. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    If you think THAT's bad, wait until you start plugging the IC's into sockets.

    [​IMG]
     
  3. VoodooMojo

    Active Member

    Nov 28, 2009
    503
    53
    not so much as to interfere with heat transfer but a single swipe with spray of clear lacquer is all that is needed.
    If it is a component that doesn't generate heat, then a bit of clear fingernail polish will work nicely.

    Just be conscience of the heat the part generates.


    Sgt, that graph is priceless!
     
  4. rjenkins

    AAC Fanatic!

    Nov 6, 2005
    1,015
    69
    The only ICs I've seen with paint or ink printed numbers in many years are the ones that are overprinted by a distributor. RS components used to do that, white ink over black paint.

    The actual IC bodies are generally laser etched and that does not wear off!
    (Though I sometimes think a microscope and 1000W lamp would help to actually read those markings..)

    Try a small amount of paint thinner or acetone (nail varnish remover) on one of the 'faded' ICs and see if it has an overprint.
     
  5. retched

    AAC Fanatic!

    Dec 5, 2009
    5,201
    312
    I use a jewelers loupe and holding the IC at an angle. Eventually the light source will catch the raised "painted" or depressed "etched" areas and you can get a decent reading.
     
  6. eblc1388

    Senior Member

    Nov 28, 2008
    1,542
    102
    Try using a magnifying glass that comes with illuminating bulb or LED.

    The laser markings will only show up clearly when the surface of the chip is at a particular angle/position to the user eyes.

    Laser markings generally makes the counterfeiter's life more difficult trying to remark other similar products to look like a higher priced product. For example, remarking a lower speed grade MCU to a higher speed one. But this doesn't seem to have stopped them as they then grind off the surface and use paint/laser to remark them.
     
  7. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    I find that clear coatings generally make it much more difficult to read the part numbers/date codes. Also, certain solvents in clear coatings may dissolve the markings.

    If it's really that much of a problem, you could use a laser printer to make labels for the ICs, and stick them on. Laser print is reasonably permanent, but some clear coat will dissolve laser printed material, too.

    Often a board will have to be conformal coated before being placed into service, particularly in harsh environments (automotive, marine, aviation, etc.) Once they've been conformal coated, it's darn near impossible to read the part numbers whether they were lasered or inked on.

    I don't handle my IC's much. They stay in a tube or ESD foam until I'm ready to use them. When you do have to handle them, try to hold them by the ends where there isn't any printing or leads. As always, make sure your hands are clean/dry before you handle your components; the oils from your skin will corrode components as well as make soldering difficult. It's best to use latex gloves or finger cots. Don't forget proper ESD procedures (ground strap on the wrist, anti-static mat, etc).
     
  8. CVMichael

    Thread Starter Senior Member

    Aug 3, 2007
    416
    17
  9. retched

    AAC Fanatic!

    Dec 5, 2009
    5,201
    312
    Permanent sunscreen. UV protectant, breathable, waterproof. ;)

    Just dont break yourself.
     
  10. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
    5,694
    904
    It will remove 20 years of age wrinkles, maybe more, from a woman's face. Also useful on snakes instead of oil.

    Let's see some facts instead of puffery.

    John
     
  11. retched

    AAC Fanatic!

    Dec 5, 2009
    5,201
    312
    It slices, it dices, look at that tomato. You can even cut a tin can with it, but you wouldn't want too.

    Mr. Popel we >heart< you.
     
Loading...