So I was trying to replace the USB port on my Samsung Galaxy, but I ended up with several pads pulled up.

Trying to learn from the experience for next time.

It seems the solder was exceptionally "sticky". I've replaced USB ports before and this time the solder did not seem to want to melt. Instead it was what I would describe as very resistant to melt and sticky....hard to wick up, hard to clean, hard to melt. I started with a working temp around 340 but had to go to 440 because 340 didn't seem to do the trick. Even at 440 it was hard to get any flow.

Just wondering what I might have done differently?

Thanks

 

You have to assume that any device made today is soldered with lead free solder. The lead free takes a higher temperature to melt. When you tried with a lower temp, and kept the iron there for a time, you weakened the bond of the pads to the board. The copper is added to the base(board) with heat setting adhesive. Then when you turned up your iron temp it weakened to copper bond even more. Always set your iron for lead free solder temps when doing repair work, if the solder is not lead free it will just melt faster, if it is lead free you won't lift the pads.

The phone may not be ruined by the pads lifting though. Just solder a short wire to the USB port, then scrape the solder resist off of the traces and solder the short (jumper) wire directly to the trace. A little hot glue or epoxy can then be used to secure the port to the board. Saves buying a new phone.

https://en.wikipedia.org/wiki/Solder

 

You have to assume that any device made today is soldered with lead free solder. The lead free takes a higher temperature to melt. When you tried with a lower temp, and kept the iron there for a time, you weakened the bond of the pads to the board. The copper is added to the base(board) with heat setting adhesive. Then when you turned up your iron temp it weakened to copper bond even more. Always set your iron for lead free solder temps when doing repair work, if the solder is not lead free it will just melt faster, if it is lead free you won't lift the pads.

The phone may not be ruined by the pads lifting though. Just solder a short wire to the USB port, then scrape the solder resist off of the traces and solder the short (jumper) wire directly to the trace. A little hot glue or epoxy can then be used to secure the port to the board. Saves buying a new phone.

https://en.wikipedia.org/wiki/Solder

Phenomenal reply ShortBus. Exactly the kind of information I was looking for

 

I did some more research into this problem. ShortBus put me on the right track. I found a solder alloy called ChipQuik that mixes with the lead free higher temp solder and thus lowers it's melting point considerably, making work like this much easier (or so I read)

So next time I have to de-solder SMD components where there is the possibility of the pads lifting, I'll use this low temp alloy solder first to make the lead free solder easier to melt and remove.

I "think" this has been a valuable lesson.

 

The curse of lead-free solder, which was a solution to a non-existent problem.

 

I did some more research into this problem. ShortBus put me on the right track. I found a solder alloy called ChipQuik that mixes with the lead free higher temp solder and thus lowers it's melting point considerably, making work like this much easier (or so I read)

So next time I have to de-solder SMD components where there is the possibility of the pads lifting, I'll use this low temp alloy solder first to make the lead free solder easier to melt and remove.

I "think" this has been a valuable lesson.

Well why not repair this one? Like most of the things I work on, they were broke when some one gave it to me. Best way to learn.

 

Well why not repair this one? Like most of the things I work on, they were broke when some one gave it to me. Best way to learn.

Looks impossible to me...let me post a hi res photo of the problem and see what you think.

 

So here's the disaster ...... should I give it a try?

.
.
.And here I've highlighted the known damage in red....

The topmost one could probably be repaired simply by removing a bit of the substrate surface and adding a tiny solder bridge.

The other two....maybe solder tiny jumper wires to the USB port pins and then solder it directly to the to SMD components?

 

So next time I have to de-solder SMD components where there is the possibility of the pads lifting, I'll use this low temp alloy solder first to make the lead free solder easier to melt and remove.

Adding some solder with lead will also make the lead free melt at a lower temp.

 

So here's the disaster ...... should I give it a try?

Doesn't look too bad. I'd be tempted to use adhesive backed copper tape, but actual PCB repair materials with epoxy would be better.

Next time, use the right tool. You should have used a hot air tool with an appropriate tip to melt the solder on all pads simultaneously. Using the wrong tool often causes grief.

 

Not a too difficult repair. You pulled up a ground and two top-side traces. Get yourself some wirewrap wire and do the repair. First, solder the new connector with LEADED solder, then use the WW wire to make the broken connections.

 

Doesn't look too bad. I'd be tempted to use adhesive backed copper tape, but actual PCB repair materials with epoxy would be better.

Next time, use the right tool. You should have used a hot air tool with an appropriate tip to melt the solder on all pads simultaneously. Using the wrong tool often causes grief.

I did use a hot air tool to remove it but still, it took a great deal of heating to get it to release. I think the pads were damaged because it took so much heat to get the solder to finally melt. I watched several videos on YouTube removing this exact port and they all seem to have pre-diluted the solder with the low temp alloy. I've ordered some now but didn't have any when I attempted the removal.

I believe that this repair would have been easy IF the solder were not the high temp stuff the factory used.

 

I was also wondering if you guys all have video microscopes for magnification and repair?

 

Not a too difficult repair. You pulled up a ground and two top-side traces. Get yourself some wirewrap wire and do the repair. First, solder the new connector with LEADED solder, then use the WW wire to make the broken connections.

Would that be 30 gauge? I've never used it before.

 

I watched several videos on YouTube removing this exact port and they all seem to have pre-diluted the solder with the low temp alloy.

I've removed many components with a hot air tool and have never had to resort to using a low temp solder. I always considered that step to be required for people trying to use a soldering iron for removing surface mount devices.

If you lifted pads with a hot air tool, you probably need to refine your technique and/or decrease temp (shouldn't need more than 400C).

 

I was also wondering if you guys all have video microscopes for magnification and repair?

Until recently, I didn't use anything; and I'm in my 60's with bad eyes. Now I have lighted magnifying visor.

 

Would that be 30 gauge?

Yes.

 

So here's the disaster ...... should I give it a try?

What do you have to lose? It's already broken, it's an expensive item that is broken, a little time to try and fix it. Even if you don't get it fixed, you will have gained some skills in trying, to use on the next repair. Nothing ventured, nothing gained. Just use lead solder on it, for lower heat.

 

What do you have to lose? It's already broken, it's an expensive item that is broken, a little time to try and fix it. Even if you don't get it fixed, you will have gained some skills in trying, to use on the next repair. Nothing ventured, nothing gained. Just use lead solder on it, for lower heat.

Afraid I'll fail...then have to face the fact I couldn't do it? lol
Also, the phone still works...and I could totally ruin it....
But I will be buying another phone soon so you're right...nothing to lose.