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    Pad repair

    Howdy good peoples;

    looking for some advice on Pad repairs, want ti expand my skills

    Working on a HP board that went for a swim; There was a short in what appeared to be the Data IC (there was corrupted data that we recovered) ;

    First picture is the donor Board, clean removal;

    Second picture is board im working on; As soon as I started prepping the pads to re work the IC, the damage started;

    As a side note, Im using good equipment M series Thermal tronics iron with a 1.6m tip; Good quality locally produced flux, good quality 1.5mm wick, and high grade 63/37 C18 wire, With proven technique, I'm going to assume this damage started when the chip failed;

    I do know of some techniques, have fixed holes through boards, done simple track repairs, but this is just a whole
    new level for me ? ( understand the solder is flowing over exposed board on the copper and this is probably all just going to ground, im too anal to let something like tha out of the shop; So would love to hear how you would fix this;

    please and thanks as always

    #2
    Comes from not using leaded solder first with a combination of not enough heat. Easy this one. Scratch the remaining trace so the copper is visible, solder the component on one pad and take a thicker wire straight over from the trace and pad to the missing pad and solder the component to it. Then put a dab of conformal coating, or green PCB paint over it.
    Sure there are other methods like cutting the pad of the donor and glueing it to the other board etc… but that's a lot of effort for this that doesn't get paid.

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      #3
      Ok yep so before I clean on a Lead free board, use lesd solder first like as if I was doing a through hole removal and clean; Makes sence;

      The IC is a QFN series might have to try and use that donor board; I could be wrong; I like that method for J leg types thats tops;

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        #4
        Unless there is a lot of dirt on the board, I don't clean it before component removal. I clean the spot before component replacement once the bad parts have been taken off the board.. After the repair is done I either clean it good with 99% IPA and a toothbrush, or stick it in my ultrasonic cleaner.
        Some old solder on the boards specifically if they are oxidized, you need to flux and add new solder, before taking anything off…
        If you just use more heat of the hot air, you risk delayering the board. Yes, the traces with the green stuff come off the board itself and make a big bubble. Sometimes the SMD component is glued to the board. Keep that in mind. There are so many ways to damage a board, it's not funny.

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          #5
          By Cleaning, I guess I should have worded it differently;

          I was removing the old solder before re tinning the pads; I cleaned the oxidisation after hot air removal of the chip; I re fluxed, then used wick, didn't move around etc etc, didn't try and lift the iron then the wick none of it; I'll make a point of adding more tin lead first in future, saves the risk of extra damage I guess;

          Ive obviously done something wrong, one of those things that will mess with me until I work it out lol; Im still going to partly blame the chip; it has failed after all 🤣🤣

          I appreciate your time advice; 👍

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            #6
            That ripped off pad is in a very convenient location. There are much dumber locations to deal with. But as long you got one solder pad to solder to you are golden. Trickier it becomes once you got no solder pads to solder to.

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