BGA solder balls not connecting - help pls

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • petemanuk
    Member
    • Feb 2022
    • 26
    • Wales - United Kingdom

    #1

    BGA solder balls not connecting - help pls

    So I though in my spare time I’d set myself up repairing motherboards mainly pin damaged lga1151 sockets types.

    I’m using an achi ir sc pro rework station (gave up on my Achie ir6500 - don’t recommend)

    I’ve managed to get my rework profile somewhere in the correct region (after a lot of trial and error) to get the old sockets off and reflow new ones back on again, the problems I’m getting is not all of the solder balls are re-attaching when re-flow occurs. I know this because when socket is removed pads still look clean and have no solder on them.

    I'm also pre-baking the boards for several hours before refolwing them to avoid delamination.

    Here’s what I’ve tried so far:

    1. Made sure all the old solder is removed and pads are clean
    2. Tried different makes of flux’s.
    3. Tried different thickness of flux between the board and new socket.
    4. Nudging the socket at reflow and you can see the surface tension pull it back into place.

    I’m getting my new sockets for aliexpress and they are coming pre-balled with unleaded solder. I’ve had a look around the net and noticed some people using a stencil and adding more solder paste to the new pre-balled socket, has anyone had experience of this?

    Also I’ve noticed that when I’ve been cleaning the motherboard bga pads that some of the are slightly sunken with the solder mask around them, I don’t think this is helping either.

    Anyway enough rambling if any one could give me some tips/guidance it would be much appreciated
    Last edited by petemanuk; 11-16-2022, 05:31 AM.
  • Th3_uN1Qu3
    Believe in
    • Jul 2010
    • 6031
    • Romania

    #2
    Re: BGA solder balls not connecting - help pls

    Out of all the above, adding some solder paste to the board pads before attempting to solder a new socket on seems like the best idea.
    Originally posted by PeteS in CA
    Remember that by the time consequences of a short-sighted decision are experienced, the idiot who made the bad decision may have already been promoted or moved on to a better job at another company.
    A working TV? How boring!

    Comment

    • petemanuk
      Member
      • Feb 2022
      • 26
      • Wales - United Kingdom

      #3
      Re: BGA solder balls not connecting - help pls

      already tried that - still made no difference with balls not connecting to the pads

      Comment

      • diif
        Badcaps Legend
        • Feb 2014
        • 6978
        • England

        #4
        Re: BGA solder balls not connecting - help pls

        Perhaps your profile isn't hot enough or doesn't hold for long enough.

        Comment

        • petemanuk
          Member
          • Feb 2022
          • 26
          • Wales - United Kingdom

          #5
          Re: BGA solder balls not connecting - help pls

          I'll double check my temps and hold times and give it another go.

          Comment

          • b0ba
            Member
            • Mar 2018
            • 12
            • Ukraine

            #6
            Re: BGA solder balls not connecting - help pls

            add flux

            Comment

            • dellxps15
              Badcaps Legend
              • Feb 2014
              • 1588
              • italy

              #7
              Re: BGA solder balls not connecting - help pls

              for bga rework i use flux..... lots of flux when removing (jetronix eco ir) and when temperature reach 232° celsius in about 7 minutes , i remove the socket (i know 233° and around 7; 7:15 minutes is ok because at around 227° the socket start moving)

              for resolder it same procedure... flux under it and at around 232° i give the socket a small move to see if it is soldered properly and all is done.

              make sure:

              1° socket is centered
              2° mainboard is perfectly orizontal (no bend of pcb)
              3° use good flux
              4 use proper rework that can heat well the pcb
              5° give the heating profile the right time to heat the pcb and melt solder (7 minutes on mine)
              6° measure with 2 thermocouple bottom and top... bottom heater must heat more then top... heat try to go up ...

              that's all and ofcourse lots of practice

              Comment

              Related Topics

              Collapse

              • menshawy
                Question about solder paste vs solder balls
                by menshawy
                hi friends
                what about using solder paste to reflow vram because it is easier than solder balls
                but it will working perfectly or it will die after short time ?
                I need your experience
                thanks
                12-04-2021, 07:49 AM
              • corrize
                Best way to solder LVDS connector for beginner (and qfn) ?
                by corrize
                Hello, I'm a beginner for micro soldering. Right now I have some difficult to solder a qfn 20, I guess I put too much solder on the thermal-ground pad, the result is a corner of chip wich don't touch the board (last try).

                I use a wire solder with hot air, I tin the board and chip before with iron and I use good flux.

                I will have to solder a LVDS connector (40 pins, laptop pc), I saw a solder paste in seringe, good quality (it does not scatter).
                See the test :
                https://youtu.be/bNAzC-EvqHs?t=1767

                With hot air from bellow the board, that's...
                03-09-2023, 02:57 AM
              • myth77
                UV solder mask - high temp resistent, recomendation?
                by myth77
                Can someone recommend any good UV solder mask? But i need a solder mask that will stand high temperetures. The thing is...sometimes i have a bigger cooper ripped from the board, lets say mosfet pad... i reconstract it with cooper sheet, then i "glue it" with solder mask...then i use UV light...and let it cool a bit. After, i try to clean the cooper of extra solder mask..and till that part all is ok. But, when i use a soldering iron to solder that pad/cooper...the solder mask gets weaker or destroyed and finally the pad is ripped again from the board .
                Is there any solder mask...
                03-28-2022, 04:04 AM
              • corrize
                What are the 2 or 3 most used BGA balls sizes please ?
                by corrize
                Hello, I want to buy BGA balls (not stencils, only balls) but I don't know what size, it's just for reballing the new chip balled if the first attempt fail. So I will rarely use it. Probably chips are PMIC with max 60 balls. I don't need to reball EC chips from laptops of big chips like that.
                So what are the 2 or 3 most used BGA balls sizes I should have for cover the jobs please ?
                05-09-2024, 02:18 PM
              • Stanley1843
                BEST 505 Vs Mechanic Brand Reballing Balls with Lead
                by Stanley1843
                Hello,
                has anyone use these Brands of solder balls? The brand BEST writes on the label of the jar the specs of the solder balls instead of the Mechanic brand. I beleive that BEST brand must be more professional (in labeling at least) but I have never try one of them so I would like your opinion. By the way I hardly can I find the Mechanic brand in aliexpress (the only where I found was lead free solder balls) and on ebay these that I found are approximately15USD per jar. If you know any other trusted brand of solder balls please tell me.
                06-22-2024, 11:06 AM
              • Loading...
              • No more items.
              Working...