thread top ad

Collapse

Announcement

Collapse
No announcement yet.

Reballing, are there tools to make it less annoying of a job?

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Reballing, are there tools to make it less annoying of a job?

    Hey everyone,

    Every now and then a SMC dies and I'll have to steal one from a dead motherboard and this requires reballing of the chip in pretty much all cases.

    Right now I got a basic reballing 'station', but even with the screws to the maximum the SMC isn't fully fitting and still slightly lose.
    This is only a small issue, the biggest issue I'm having is that with solder paste, the flux dries up while heating the paste which ends up making the SMC stick to the stencil, ruining the reballing job in most cases. Or the balls end up floating inside the stencil, not touching the SMC so the balls are not being applied to the SMC. To make it even more of a chaos every now and then balls just merge from underneath the stencil with each other. If after two or three times I finally get it right, I have to pray I didn't fry the SMC and have to start over again.

    Short story: My reballing is a mess

    I was wondering if anyone had recommended tools, temperature settings and paste to use?
    I don't even mind paying good cash for a amazing chip and stencil holder because its such a pain in the butt right now.

    Cheers

  • #2
    I use heat directly stencil, the 3USD holder for that kind of stencil and 0.35 solder balls....... The job is done in about 2 minutes...

    Comment


    • #3
      I've never seen the directly heated stencil holder like that, its definitely worth giving a try for 3USD!

      What kind of temperature do you usually use? Air speed setting at low?

      Comment


      • #4
        This is the holder...

        http://www.ebay.com/itm/Heat-Directl...oAAOSwCQZZAchT

        Settings depends on your hot air station, mine is a hakko FR-802 450ºC and air good enough to not blow balls out of the stencil..

        Comment


        • #5
          Thanks, I just ordered the same one and will see if it works better then my current setup

          Comment


          • #6
            The new holder works much better, still not as easy as I'd like but atleast I'm usually succeeding

            Comment


            • #7
              Actually no, it does help a little but I still suck at it.

              I often have the issue of soldering the stencil and the SMC together, so they won't come off.

              My failing workflow goes like this:
              1. Place the SMC and stencil on the holder linked above and align
              2. Spend 5 to 10 minutes trying to get all the balls in (pain in the butt)
              3. Heat up the balls, they melt but most do not solder onto the SMC or get stuck soldered onto the stencil.
              4. Add flux in the hope the flux helps guide the balls into doing the right thing
              5. Now the balls are alright and soldered onto the SMC in most cases, but the flux is sticking the SMC onto the stencil
              5.1. Try to remove the stencil while keeping the balls heated --> SMC gets slightly pulled up by the stencil and then falls onto your desk and the balls are ruined
              OR
              5.2 Try to remove the stencil after the balls are cooled --> High chance of one or more balls still soldered onto the stencil, keeping the SMC stuck onto the stencil or ripping the pads of the SMC (very sad)
              6. Repeat this a couple of times until you have suffered enough for the world to decide to let you succeed. Then hope you didn't burn the SMC and it will work.

              Thankfully I still have some pre-balled SMC's from ali for a couple of models, but I'm slowly running out and they're becoming harder to find. Also I feel like being able to reball chips is just crucial knowledge for this job

              Can someone describe their in-depth explanation of how they reball small ICs like this? What tools do you use? I feel like both my inexperience and lack of proper tools are causing this

              My blood pressure thanks you all
              Last edited by smiba; 10-22-2017, 12:35 PM.

              Comment


              • #8
                I'm not exactly in the position to be handing out tips, seeing that I've got only a couple of reballs under my belt, but as you've helped me get things a little smoother I'll do my best to be of some help.
                One thing that was making my reballs after the first one much harder turned out to be crap in my stencil. They looked clean at a glance, but many a ball was getting stuck in nasty old flux and refused to drop down onto the SMC. I tried cleaning the stencils with a lot of franctic toothbrush action, but the situation didnt improve until after I dumped the stencil into my UC for about 15 minutes. That didnt even get all the superficial junk off, but it did must have cleaned the holes decently, because my next reball had about 3 balls stay in the stencil instead of the 15+ I had before.
                Placing single balls stinks, but its doable and means I dont have to start completely over. I just add a little flux to each empty pad, place a ball and carefully apply hot air (low airflow).

                Also, Dave Richies from Advanced Reworks linked me this one: https://www.youtube.com/watch?v=jRhw8-tA15o&t=978s . It start at 16:18 for the reballing itself. Perhaps there's a little something you can use.

                Comment


                • #9
                  smiba, you should put a small amount of flux on the SMC before put and align the stencil, after that throw the solder balls over the stencil and they will stick in place by itself becasue of the flux applied..

                  Comment

                  thread bottom ad

                  Collapse
                  Working...
                  X