Greetings to all!
I need to safely remove a through-hole DIP IC from an old ISA soundcard. See the picture. The board doesn´t matter and can be trashed. I´m not sure if it´s double-layer or multi-layer. The holes seem very tight on the pins and there´s solder on both faces of the card, on all pins.
I do have some ideas, but not the right tools (I wish I had a Dremel)... So I´d like to hear your ideas on this. All help is highly appreciated!
Thanks,
Alexandre
I need to safely remove a through-hole DIP IC from an old ISA soundcard. See the picture. The board doesn´t matter and can be trashed. I´m not sure if it´s double-layer or multi-layer. The holes seem very tight on the pins and there´s solder on both faces of the card, on all pins.
I do have some ideas, but not the right tools (I wish I had a Dremel)... So I´d like to hear your ideas on this. All help is highly appreciated!
Thanks,
Alexandre
Attachments
The best way to remove this IC is by using a very expensive vacuum desoldering iron. Second choice is to get a cheap desoldering iron like the Weller DS-40. You can also use the non-heated pump vacuum type in combination with some type of solder wick. In all cases, you should also use liquid RMA flux. Flux is your friend.
It is much easier to save the board than the IC. It's hard to get a DIP package off a through hole board even with a good solder sucker.
If itbwere my problem I wopuls suck out as much solder as possible and if it still doesn't come out gently, I would get out the Demel tool and cut the board *carefully*right up to the pins to expose them the complete the desoldering
If itbwere my problem I wopuls suck out as much solder as possible and if it still doesn't come out gently, I would get out the Demel tool and cut the board *carefully*right up to the pins to expose them the complete the desoldering
Depends; some do, some don't.sagarverma said:
If it doesn't come out by removing solder,use the opposite method: Melt lots of solder and spread it down each row in turn. The IC will fall out by gravity. Do the job as quickly as possible with the highest wattage iron to hand - 2 if you have them.
Thanks for all the replies. I´ve been practicing on some other ICs with a desoldering pump, but I don´t think this will do.
I actually liked the
fire idea (by peranders), but I´ll leave that as a last resort!
Someone suggested using two irons at once, thats nice! I think I´ll try bending copper wire to an "L" shape and use this tip on the iron, to touch the entire row of pins.
I´ll let you all know how it goes!
Best regars,
Alexandre
I actually liked the
fire idea (by peranders), but I´ll leave that as a last resort!Someone suggested using two irons at once, thats nice! I think I´ll try bending copper wire to an "L" shape and use this tip on the iron, to touch the entire row of pins.
I´ll let you all know how it goes!
Best regars,
Alexandre
Removing IC
Hi Alexandre,
same name as me, almost. I'm Alexander.
There have been a few suggestions above and I'm afraid most should be taken with a pinch of salt. No offence meant.
Patience is the name of the game, where a large number of pins need to be removed, unless you have the correct speed tools.
If the IC is important to you, then any method involving blowtorches, lighters and flame of any variety should be discounted fairly quickly, as the chip will almost certainly be fried. Especially if a large number of pins is involved.
Looking at the picture you have posted, your IC appears to be a 28 pin, or possibly 40 pin DIL.
It also appears, contrary to your post, that there is very little solder on the component side. Is this correct?
If so, then desoldering braid is probably the best way to go.
This braid works best when there is a reasonable amount of solder to work with, so examine the undeside of the board and silly 'though it might seem, like another poster above, I suggest that if the joints appear solder deficient, then re-solder the joints prior to de-soldering. Give the braid something to work with.
Use a good, hot, bolt and apply the braid to each joint but go from side to side of the chip, to spread the heat.
When you have done half of the pins, walk away and have a can of coke, or something, and let the chip cool down.
Go back and do the other half of the pins.
At this point, get a small screwdriver and press against the joints.
If they are free, you will easily see them move.
If not, press a bit harder and usually, the joint will break loose with an audible crack.
If it doesn't, re-solder the joint and de-solder with braid again. Don't waste your time trying to use braid on the previously de-soldered joint. Always re-solder.
Eventually, all the joints will free up and the chip will come out easily.
HTH,
Sandy.
Hi Alexandre,
same name as me, almost. I'm Alexander.
There have been a few suggestions above and I'm afraid most should be taken with a pinch of salt. No offence meant.
Patience is the name of the game, where a large number of pins need to be removed, unless you have the correct speed tools.
If the IC is important to you, then any method involving blowtorches, lighters and flame of any variety should be discounted fairly quickly, as the chip will almost certainly be fried. Especially if a large number of pins is involved.
Looking at the picture you have posted, your IC appears to be a 28 pin, or possibly 40 pin DIL.
It also appears, contrary to your post, that there is very little solder on the component side. Is this correct?
If so, then desoldering braid is probably the best way to go.
This braid works best when there is a reasonable amount of solder to work with, so examine the undeside of the board and silly 'though it might seem, like another poster above, I suggest that if the joints appear solder deficient, then re-solder the joints prior to de-soldering. Give the braid something to work with.
Use a good, hot, bolt and apply the braid to each joint but go from side to side of the chip, to spread the heat.
When you have done half of the pins, walk away and have a can of coke, or something, and let the chip cool down.
Go back and do the other half of the pins.
At this point, get a small screwdriver and press against the joints.
If they are free, you will easily see them move.
If not, press a bit harder and usually, the joint will break loose with an audible crack.
If it doesn't, re-solder the joint and de-solder with braid again. Don't waste your time trying to use braid on the previously de-soldered joint. Always re-solder.
Eventually, all the joints will free up and the chip will come out easily.
HTH,
Sandy.
Sometimes it can help if you spray the chip well with a freezer can before you begin, if you are attempting to desolder the pins as suggested.
In my experience this does not make much difference to the pins heating up if you are merely doing the removal this way, but might help to avoid frying the chip if the soldering iron is applied for longer than is ideal.
It wouldn't be a good idea if you are using a stove, or whatever, to heat the entire assembly, as this will just increase the time of heating overall.
In my experience this does not make much difference to the pins heating up if you are merely doing the removal this way, but might help to avoid frying the chip if the soldering iron is applied for longer than is ideal.
It wouldn't be a good idea if you are using a stove, or whatever, to heat the entire assembly, as this will just increase the time of heating overall.
Hmm.
If this were my problem, I think I would just cut the pins as close to the PCB as possible rather than risk overheating something that might not be replaceable.
It is much simpler then to extend the pins for the new PCB, or if you go for a skeletal type socket, you might be able to solder directly to that.
If this were my problem, I think I would just cut the pins as close to the PCB as possible rather than risk overheating something that might not be replaceable.
It is much simpler then to extend the pins for the new PCB, or if you go for a skeletal type socket, you might be able to solder directly to that.
If this were a single sided board, you could wick the pins or use a solder sucker; but its not. You will never get all the solder out of the holes. 
Hot air is the "pro" way to do it, but you probably don't have a heat gun that will get hot enough.
A huge solder pot is a nice way to go... float the entire board on the solder, wait about 10 seconds and lift out chip. Bet you don't have solder pot big enough to float the board...
A desoldering tip that hits all leads at once is nice... got one?
Soldering all the pins together is nice... got 8 hands and 4 irons?
Seriously, throw a scrap board on the kitchen stove and practice. When you see how easy it is... report back.
Otherwise, use the PinkMouse method... cut the chip out and extend the leads later.
Hot air is the "pro" way to do it, but you probably don't have a heat gun that will get hot enough.
A huge solder pot is a nice way to go... float the entire board on the solder, wait about 10 seconds and lift out chip. Bet you don't have solder pot big enough to float the board...
A desoldering tip that hits all leads at once is nice... got one?
Soldering all the pins together is nice... got 8 hands and 4 irons?
Seriously, throw a scrap board on the kitchen stove and practice. When you see how easy it is... report back.
Otherwise, use the PinkMouse method... cut the chip out and extend the leads later.
You can get some 500°C heat guns for 20$.
You could use the toaster oven SMD soldering technique, but pull the chip while the solder is still melted instead of letting things cool down.
Also, in the wiki, there's an article on SMD rework. Maybe the DIY hot air pencil could work...
http://www.diyaudio.com/wiki/index.php?page=SurfaceMountDeviceRework
You can easily cut the PCB with a metal saw also.
You could use the toaster oven SMD soldering technique, but pull the chip while the solder is still melted instead of letting things cool down.
Also, in the wiki, there's an article on SMD rework. Maybe the DIY hot air pencil could work...
http://www.diyaudio.com/wiki/index.php?page=SurfaceMountDeviceRework
You can easily cut the PCB with a metal saw also.
First of all, thanks for all the suggestions!
I got the IC out in (supposedly) good shape. Haven´t tested it yet. I ended up using my soldering iron, and a special solder with a very low melting temperature. It stays melted for several seconds. The key here is to suck some of the old solder with a common desoldering pump, then put a lot of this low-temp solder over all pins of the IC. It stays melted so you have some time to force the IC out. It didn´t come out too easily though.
This product is sold locally with a name like "smd-saver".
(I just hope I haven´t overheated the IC.....)
Thanks & Best regards!!
Alexandre
I got the IC out in (supposedly) good shape. Haven´t tested it yet. I ended up using my soldering iron, and a special solder with a very low melting temperature. It stays melted for several seconds. The key here is to suck some of the old solder with a common desoldering pump, then put a lot of this low-temp solder over all pins of the IC. It stays melted so you have some time to force the IC out. It didn´t come out too easily though.
This product is sold locally with a name like "smd-saver".
(I just hope I haven´t overheated the IC.....)
Thanks & Best regards!!
Alexandre
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.