0
\$\begingroup\$

The chip is a chip that is surface mounted to the main PCB. This solder gave out and separated from the PCB as shown below.

I'm not very well skilled in soldering, but it seems a bit too fine for a normal soldering iron. Should I use solder paste and a heat gun? Or is there a better way?

\$\endgroup\$

closed as off-topic by Dmitry Grigoryev, Dave Tweed Jun 23 '17 at 11:37

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "Questions on the repair of consumer electronics, appliances, or other devices must involve specific troubleshooting steps and demonstrate a good understanding of the underlying design of the device being repaired. See also: Is asking on how to fix a faulty circuit on topic?" – Dave Tweed
If this question can be reworded to fit the rules in the help center, please edit the question.

  • 3
    \$\begingroup\$ Your photo contains far too much irrelevant stuff, take a picture of the line of pads on the main PCB with the daughter board just below nearby so people can get a better look at the important area. After adequate cleanup it surely won't be a problem for a normal electronics soldering iron even with a relatively large tip. If the boards have adequate solder mask, you shouldn't have any trouble at all. \$\endgroup\$ – replete Jun 23 '17 at 7:31
  • 3
    \$\begingroup\$ Winny might be skilled enough to use a heat gun on something he wants to use afterwards, I only use one for destructive disassembly! That pad pitch is fine for an ordinary soldering iron. \$\endgroup\$ – Neil_UK Jun 23 '17 at 7:32
  • 4
    \$\begingroup\$ It looks slightly lame design for that relatively long daughter board to be held only by the solder joints. Any sort of vibration and it's only a matter of time before it's off again. Secure it in a few places with hot melt. \$\endgroup\$ – replete Jun 23 '17 at 7:36
  • 2
    \$\begingroup\$ Sorry, but I don't see how this can be answered objectively. You already know the options, and whichever is better depends solely on your skill with it. \$\endgroup\$ – Dmitry Grigoryev Jun 23 '17 at 7:49
  • 2
    \$\begingroup\$ To me it looks like you ripped off the pads as well, making it impossible to solder again. But this is hard to judge given the quality of images supplied. \$\endgroup\$ – asdfex Jun 23 '17 at 9:01
2
\$\begingroup\$

Just use a normal soldering iron (preferably temperature controlled) and liquid solder flux. Apply flux liberally, then put a little solder on the iron tip and rake it down the pins on an angle to heat up several pins at once (or use a 3mm spade tip like I do).

The flux should prevent solder from bridging the pins. If a solder bridge does occur then use desoldering braid to remove it.

\$\endgroup\$
1
\$\begingroup\$

If you do not want to use solder iron, then here is an alternate method:

  1. Apply liquid flux on the pads of the IC.
  2. Apply some solder on the pads and then place the IC carefully in place, and
  3. Use the hot air blower/heat gun to secure it firmly in place.

PS: Where your IC pads are, I can see some capacitors and other components. So, you'll have to use your heat gun very carefully.

I'd personally prefer to solder this IC than relying on heat gun to do the job. If the heat gun displaces the caps while placing your IC correctly, re-placing those caps would be much tougher later.

\$\endgroup\$
0
\$\begingroup\$

I would go at it like this.

  1. Use solder wick to clean the pads of both boards. You want the pads of both to be clean and smooth.

  2. Use a soldering iron with a fine tip, and 0.5 mm solder. It can be done with thicker solder, but I use 0.5mm for just about everything.

  3. Heat one pad one the main board with the iron, and melt a bit of solder onto the pad.

  4. Put the smaller module in place and line it up properly.

  5. Melt the solder on the one tinned pad, and push the smaller board down on the larger one so that they are flat on one another.

  6. Remove the iron and let the pad cool.

  7. Check alignmeny. If crooked, reheat and adjust.

  8. Solder all of the pads, including the first one. It won't be perfect because of the reheating, so it must be redone.

\$\endgroup\$

Not the answer you're looking for? Browse other questions tagged or ask your own question.