Hot Air Rework Station

nutballchamp

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Does anyone ever use a Hot Air Rework for through chips? I've done this by using a small tip and alternating heating the top legs and bottom legs until the chip falls out. It works but it's hard not to burn the board. Do I need more practice or is it better to stick with cutting out the chip and de-soldering the legs one at a time? I tried the Hot Air as I was pulling traces with the de-soldering method.
 
You should get a soldering station that has a desoldering iron and a built in vacuum pump.
 
You should get a soldering station that has a desoldering iron and a built in vacuum pump.

Do you cut the chip out or desolder all the pins with the desolder station and hope the chip will come out? I ruined a board by cutting out the chip, heating the solder on the pins and pulling them out one at a time. I pulled lots of traces this way and was told to get a rework station. Rework doesn't pull traces, but burns the board. Thanks.
 
I desolder all the pins individually. If the power and ground pins are stubborn the I just put the iron on the top side, desoldering iron on the bottom and it cleanly desolders those pins.

Next I take some duck bill pliers to slightly twist the chip clockwise then counter-clockwise a couple of times. This breaks the pins loose from any tiny remaining bits of solder. At that point the chip should lift straight out without pulling any traces.

RJ
 
I desolder all the pins individually. If the power and ground pins are stubborn the I just put the iron on the top side, desoldering iron on the bottom and it cleanly desolders those pins.

Next I take some duck bill pliers to slightly twist the chip clockwise then counter-clockwise a couple of times. This breaks the pins loose from any tiny remaining bits of solder. At that point the chip should lift straight out without pulling any traces.

RJ

Awesome, thanks. Any recommendations for a desolder station?
 
I use PACE gear... but any decent name brand gear that you can get the maintenance pieces for will work fine.
 
Looks pretty cheap... but if it works good then it's a good buy.
 
Does anyone ever use a Hot Air Rework for through chips? I've done this by using a small tip and alternating heating the top legs and bottom legs until the chip falls out. It works but it's hard not to burn the board. Do I need more practice or is it better to stick with cutting out the chip and de-soldering the legs one at a time? I tried the Hot Air as I was pulling traces with the de-soldering method.

If you're going to use hot are for through hole, you *really* need to solder suck the power pins first so they're clean. The extra thermal mass on the large nets is what's holding the chip in while the rest of the area burns...

I just use a good quality Sold-a-pullt with my normal iron... fancy 'desoldering stations' are mostly a waste of money. With how much maintenance they requre, and how much they clog up, I don't think they save much time over a $12 disposable soldapullt... heh
 
If you're going to use hot are for through hole, you *really* need to solder suck the power pins first so they're clean. The extra thermal mass on the large nets is what's holding the chip in while the rest of the area burns...

I think you nailed the problem I was having. Seemed like all the solder was melting before the board would burn and the chip still wouldn't come out. Sometimes I would gently pry it out and it would be stuck on the power rail side. Thanks!
 
Can't go wrong with that brand name. It's a good one and you shouldn't have issues finding supplies for it. You should be able to find supplies at your local Fry's.
 
I also use a Hakko 808 here. Once you go to a proper vacuum desoldering tool, you'll never go back. It's night and day stepping up to it from wicks or soldapults.

-Hans
 
If you're going to use hot are for through hole, you *really* need to solder suck the power pins first so they're clean. The extra thermal mass on the large nets is what's holding the chip in while the rest of the area burns...

I just use a good quality Sold-a-pullt with my normal iron... fancy 'desoldering stations' are mostly a waste of money. With how much maintenance they requre, and how much they clog up, I don't think they save much time over a $12 disposable soldapullt... heh

Agreed. I do all my repairs this way. Snip off the problematic IC one leg at a time and pull them out with tweezers while heating them up from the other side.
Once you get the knack.. you can remove IC's in minutes. And it's a much more affordable approach.
 
Agreed. I do all my repairs this way. Snip off the problematic IC one leg at a time and pull them out with tweezers while heating them up from the other side.
Once you get the knack.. you can remove IC's in minutes. And it's a much more affordable approach.

Do you do this on sockets without pulling traces? I did this approach to my Centaur MPU sockets and was pulling about 3-4 traces per socket. I jumpered the traces and it didn't work anymore so I gave up. I've done it successfully on 74ls chips. I'm going to get a Hakko 808 and try sucking out the solder first and use the rework to remove the chip.

Edit: ajcrm125 are you using rework to heat the other side after cutting out the chip? I was using a solder iron on the method above. Maybe the rework will heat the top and bottom enough not to pull traces?
 
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Do you do this on sockets without pulling traces? I did this approach to my Centaur MPU sockets and was pulling about 3-4 traces per socket. I jumpered the traces and it didn't work anymore so I gave up. I've done it successfully on 74ls chips. I'm going to get a Hakko 808 and try sucking out the solder first and use the rework to remove the chip.

Edit: ajcrm125 are you using rework to heat the other side after cutting out the chip? I was using a solder iron on the method above. Maybe the rework will heat the top and bottom enough not to pull traces?

I haven't pulled a trace to date. If I hadn't snipped off the legs of the IC first and somehow tried to get the whole chip off the board at once (using hot air or something similar) I'd bet this would happen.

I have a PCB vice that I use to hold the board vertically. With a pair of tweezers in my left hand I grab a pin on the snipped side and touch the same pin on the other side of the board with the soldering gun in my right hand. As soon as the solder melts it comes right out. Once all the pins are out I do the same method with a solder-sucker in the left hand and clean out all the holes.
 
I have used this product http://www.chipquikinc.com/ mostly for SMD de-soldering and rework. However I have also used it a couple of times with stubborn through hole mounted chips.

In my experience lifting traces is due to to much heat. Sometimes I need to get more solder and flux in there before I get it all out with a solder sucker or de-soldering station. It helps adding the new solder that is eutectic with low melting point. The quick chip is basically the same idea but to the extreme.
 
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