I can't desolder a female USB from an IC

spinnaker

Joined Oct 29, 2009
7,837
Hello,

A trick you can use with these more stubborn parts is to work on ONE pin at a time, and that may include the body pins also...one at a time. If you only have two pins to unsolder you can usually heat one up at a time and pry one leg out a little, then go back to the other leg, then back to the previous leg, etc., until the part comes out. But when there are more than two pins it gets harder, so a trick is to detach all the pins from the main body of the part and then heat up and easily remove each pin one by one.

Detaching could mean simply cutting the pins off the body, all of them, one by one with a flush cutting wire cutter, or it could mean grinding the part with a small grinding wheel such as on a Dremel, and then cutting the pins or grinding them off the main body.
Once the pins are detached from the main body they unsolder very easily because they are small and heat up fast and they come out easy unless they were jammed into a hole that was too small in the first place.

You can use this trick with IC chips too, DIP or SMD parts. Of course you cant use the part after that but usually it's the board that is more important.

Good luck :)
I think the OP is trying to salvaging parts or at least practicing removing parts without damage. But yes any time I remove a part with more than 3 or 4 legs I break it up and remove each pin. A whole lot easier. :)
 

Sensacell

Joined Jun 19, 2012
2,449
Keep in mind that sometimes you just cannot remove a part without damaging or destroying the part or the board.
It's just a fact of life, even with all the most expensive fancy de-soldering tools.

PCB's are not intended to be repaired, if you can, great, but don't expect it to be easy.
 

MrAl

Joined Jun 17, 2014
6,602
Hi,

Yes if the part is being removed for use in another project, then if you cut the pins obviously it will be much harder or impossible to use in the next project because the pins will be shorter. It all depends what you are willing to go through in that case, and how much the part costs when new.

I am actually going to try an idea today that involves removing a 'header' from a small circuit board.
The board is known as a "TinyRTC" real time clock board, and when i got the board the male header was soldered into the board upside down, so all the pins are too short to connect any female jumpers so i was going to remove it completely, but not have to solder it back on the right way.
Since there are several pins in this header, i was going to try using a heat gun. Heating all the pins at once by moving the heat gun nozzle back and forth over the row of pins on the underside of the board, then gently pushing on the pins to see if the thing will start to move out of the board holes.
This isnt a critical thing as i dont think the RTC chip works anymore anyway, but i think the 32k EEPROM chip still works so i might try to salvage that. The main thing though is i want to see if using a heat gun can help remove a male header without cutting the pins apart.
I also might try removing a female header at some point, because they tend to wear out after a while if using one repeatedly with a prototype board like the Arduino Uno, where you plug wires in and unplug and plug in again for testing various projects without having to solder anything. The female headers wear out so the jumper wires fall out too easy and dont make good contact anymore, so replacing one might be a good thing to do after it wears out. This of course means heating up a line of pins all at the same time or else cutting the header up first before unsoldering each pin one by one.
If this works i'll post some pics here.
 

MrAl

Joined Jun 17, 2014
6,602
Hello again,

Here are a couple pics of removing a male header from a TinyRTC proto board.
The first pic is 'before', showing the pins soldered into the board holes.
The second pic is 'after', showing the board with holes only and the removed pins to the left.

Note that the header was the one on the left side of the board in the pic, the one with the more pins (holes).
The other header on the right was removed by someone else and they used a soldering iron.
We can see that using a heat gun works better, but it wasnt easy because all of the pins were hard to heat up all at the same time, and when i tried that what happened was the male header plastic on the other side of the board started to melt, and that meant some of the pins became detached from the header plastic and so they could be removed one at a time. That wasnt intended, but that is what happened so i went with it and removed all the pins except for some that stayed in the header plastic. The pins and what remains of the header plastic is pictured on the left side of the second photo.

So it did not work as well as i was hoping, but it did work, and the board does not look like it was damaged too much. After doing this though it think i would rather just cut the pins apart by cutting the header plastic between the pins with a cutting disc on the Dremel. I would rather do that beause this took a LOT of heating just to remove that one small header, and all the while the PC board is heated as well because the solder in the holes has to be melted. This much prolonged heating i dont think is good for the PC board. It would require much less heat if the pins were separated to begin with. So next time i'll cut them apart first, then desolder each one separately. The headers are not that expensive and the board is what we usually want to keep.

RTC_Board-1.jpg RTC_Board-2.jpg
 

MrSoftware

Joined Oct 29, 2013
1,571
In my limited experience, seeing the amount of copper on the board, it's going to be difficult to keep an area hot unless you heat the whole thing, with hot air. Also the tip you use on your iron will make a very big difference. The little pointy tips aren't so good for areas that need a lot of heat. Try a tip that's a little wider and beefier, it will have more heat capacity and transfer more heat to your parts. Make sure the tip is clean, and add a little new solder to help melt the old solder before sucking.

Also try an electric desoldering tool, possibly in combination with your iron. I've seen people struggle with those little spring loaded solder suckers so I never tried one myself, skipping right to the heated versions. I started with one of the $25 versions and it's not perfect, but it sure beats a soldering iron alone:

http://www.amazon.com/s/ref=nb_sb_noss_2?url=search-alias=aps&field-keywords=desoldering+iron&rh=i:aps,k:desoldering+iron
 

ian field

Joined Oct 27, 2012
6,540
Hello again,

Here are a couple pics of removing a male header from a TinyRTC proto board.
The first pic is 'before', showing the pins soldered into the board holes.
The second pic is 'after', showing the board with holes only and the removed pins to the left.

Note that the header was the one on the left side of the board in the pic, the one with the more pins (holes).
The other header on the right was removed by someone else and they used a soldering iron.
We can see that using a heat gun works better, but it wasnt easy because all of the pins were hard to heat up all at the same time, and when i tried that what happened was the male header plastic on the other side of the board started to melt, and that meant some of the pins became detached from the header plastic and so they could be removed one at a time. That wasnt intended, but that is what happened so i went with it and removed all the pins except for some that stayed in the header plastic. The pins and what remains of the header plastic is pictured on the left side of the second photo.

So it did not work as well as i was hoping, but it did work, and the board does not look like it was damaged too much. After doing this though it think i would rather just cut the pins apart by cutting the header plastic between the pins with a cutting disc on the Dremel. I would rather do that beause this took a LOT of heating just to remove that one small header, and all the while the PC board is heated as well because the solder in the holes has to be melted. This much prolonged heating i dont think is good for the PC board. It would require much less heat if the pins were separated to begin with. So next time i'll cut them apart first, then desolder each one separately. The headers are not that expensive and the board is what we usually want to keep.

View attachment 94933 View attachment 94934
Looking at the mess made of those pads.................................

Those plastic headers barely grip the pins at the best of times, they practically fall out at soldering temperature - I'd just unsolder each pin one by one and pull it out with pointy nose pliers while the solder is melted.
 

MrAl

Joined Jun 17, 2014
6,602
Hello again,

Well i checked the pads on the side that i unsoldered and they dont look too bad. That is the side with the most pins. The other side was really messed up but that was done by someone else with just a soldering iron.
The ones i did still need a little melting/solder sucking yet to clear the holes, but that should do it i think.
 
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