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So I have to replace a SMD connector, and although i do have soldering experience, it's all with THT. I watched like 10 different YouTube videos on chip quik, and they all made it look so easy, so i figured I'd give it a try.

I've been trying to practice on an old junk motherboard first, but it feels like I must be doing something wrong.

First, I've noticed that it's pretty much impossible to tin the tip with chip quik, so I've tried both without tinning and tinning with normal solder, with pretty much the same results.

The way SMD soldering is applied with the tip is very new to me. I cover the joints in flux, but when I try to spread the solder out like they do in the videos, it just balls up and doesnt want to stick to any of the pins. I know this issue is usually caused by the joints not being hot enough, but none of the people in any of the videos heated up the joints, they just spread it out over the pins and kept it molten while they pulled the chip off.

After being very delicate, I managed to get the solder distributed over the joints, but when I try to make a second pass to keep the solder molten, it just balls up and pools wherever I put the iron, repelling away from many of the joints.

I have tried messing with my iron temp anywhere from the range of 250c to 400c with pretty much the same results. Have also tried both cone tips and chisel tips.

Could it be a problem with the quality of my tips or am I doing something wrong? It was a really cheap soldering iron but had great reviews and hasn't given me any problems yet. All of the tips I used were either new or only used a once or twice. I know theres probably some better quality tips out there but I'm not even sure how to find ones that fit. Most of the good ones seem to be for Weller irons.

Any input is greatly appreciated. I managed to successfully remove 1 SMD chip so far after some struggle, but all of the other attempts I couldn't even get it to budge.

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    \$\begingroup\$ A motherboard is kind of a bad board to practice on because it has many layers of almost solid copper, so it will take a lot of heat to melt the solder. See if you can find single or double layer boards to practice on. \$\endgroup\$
    – Wesley Lee
    May 16, 2019 at 19:36
  • \$\begingroup\$ It requires a wedge tip with more heat but lower temp vs a small tip with higher temp. The lower temp solder acts a heat conduit to a broader size and longer molten time. Making it too hot without flux causes balls. \$\endgroup\$
    – Tony Stewart EE75
    May 16, 2019 at 19:45
  • \$\begingroup\$ Like Wesley said, a motherboard has many very large planes of solid copper that act like a heatsink. You will need a large chisel tip (like 2.4mm or larger) with a good iron (one that is powerful but has good temperature-control so it doesn't burn anything) or a PCB preheater. Sometimes you need both. Your motherboard is also likely to be using lead-free solder if it was made in the past 15 years or so, which makes things even tougher. You will also need extra flux. My JBC station sometimes has trouble without a pre-heater, especially with smaller tips and that's top of the line. \$\endgroup\$
    – DKNguyen
    May 16, 2019 at 19:49
  • \$\begingroup\$ Are you running into trouble removing the part? or are you trying to solve a problem with solder bridging? Chipquick makes a removal kit (but I've found cheap rework stations and hot air to be much more effective personally) removal with an iron is messy though the demo videos make it look easy, and drag soldering is tough and you'll need to play around with your flux, solder and temperatures with a good clean tip to get it working properly. \$\endgroup\$
    – Drew Macrae
    May 16, 2019 at 23:01

3 Answers 3

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Be aware that old motherboards have crappy solder that's been sitting under a pile of dust for a long time. Sometimes I find that old solder like that doesn't want to melt. Before using the chipquik, I'd recommend using some flux and fresh solder to tin the old solder, so that it will melt much easier and accept new solder better. If you're crafty you can remove the old solder with solder wick/braid and tin with new solder.

I've never actually used the chipquik for removing chips, so I won't try to help you there, but I can get most chips off easily enough with my Hakko FX888-D and the standard T18-D16 chisel tip (a very small chisel) at 750F. Using a hot air station is definitely easier, but those can get quite expensive for a good one (my Hakko 810B one runs around 800$ new). For the hot air gun I find it easiest to use solder wick to remove as much solder as possible, then use the air gun to heat all sides evenly till it pops off. I definitely recommend investing in one (they come at a decent price from China that should work good enough).

But you are using a soldering iron. I'm sure some people will crucify me for saying this but I if I have a stubborn chip and no hot air gun, sometimes I'll use a razor blade to help lift the chip off the board. First I apply flux to all the leads of the chip, then add a decent amount of solder to 2 of the 4 sides. I then gently maneuver my razor blade under the corner joining 2 sides and run my soldering iron with a good ball of solder up and down both sides, switching as quickly as possible. Once it's heated up enough, you can twist or lift the razor blade very gently and it will begin to lift off both sides. Then you can get the blade further under the chip, remove excess solder with wick and continue the process. Obviously this method runs the risk of damaging traces underneath the board with the razor blade, so use extreme caution. You can usually tell if the area is trace free, and also you don't need to use much pressure at all on the blade if you properly heat the chip. I've also seen a guy use a dab of CA and bond a wooden dowel to the chip, and use that lift the chip off. It's a hack for sure but will work in a pinch. Good luck with your chip removal!

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  • \$\begingroup\$ I find haphazard heating to make that process too dangerous (and jumping from side to side with the iron counts as that). What I do instead is heat and lift just one side VERY slightly so contact is broken. Then I desolder the other side as normal. Instead of a razor, I use a straight dental probe with a 20 degree bend in the middle (since my hands are above the PCB) and lightly pressure it parallel to the PCB so it runs under the row of pins when it's hot enough. No lift motion. The thickness of the probe does the lifting and ensure it does not tilt too much and lift traces on the other side. \$\endgroup\$
    – DKNguyen
    May 16, 2019 at 22:08
  • \$\begingroup\$ And instead of running the iron back and forth along the row to try and heat it all up at the same time, I run the iron just ahead of the probe so the probe lifts the pins right in front of it as the solder melts. Use a big, enormous, massive oversized tip so it can heat up multiple pins ahead. It makes it both faster and safer because you know the solder is melted for sure without need to apply pressure to the probe to test. Having a blade tip that heats up the entire row at the same time is safest though. \$\endgroup\$
    – DKNguyen
    May 16, 2019 at 22:16
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I tried this chipquik stuff before. it doesn't flow like regular solder. I had the same issues you are having, where its surface tension will cause it to ball up and not flow. I had to use a lot of flux to get it to flow better, but in the end, it was a headache. Not only that, but cleanup is a pain in the neck. you have to make sure to get every little bit out.

In the end, I found it easier, and quicker(no pun intended) to just use regular leaded solder on all the joints(to lower the solder melting point on lead free solder used on the joints), then use a heatgun to remove the chip. since the melting point is lower than the rest of the solder on the other components, our chip will come off with less heat than what is needed to melt solder on nearby components.

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If you do not need old connector then often easiest way is to separate it's pins first by cutting connector body any way you like (dremel, wire cutters etc.), then removing pins one by one.

If that is impossible, use chisel tip. Cut a piece of heavy gauge copper wire and bend it to go over all pins. Cover it with flux then use generous amount of regular solder all over. Do not take iron off the wire, it can be very hard to re-heat it later. Instead move tip to the center of the wire and wait until solder melts all along.

See this technique here, at 2:12, 3:02, 4:15

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