Salvaging ICs

[JHGibson]

On occasion, I would have a trash PCB on which there would be some useful ICs or transistors which I wanted to save.
The technique I used was to mount the PCB vertically in a vise, take a firm grip on the IC with a pair of pliers but not too firm that the component would be crushed.
While pulling gently outward, I would apply a small propane flame to the IC pins on the trace side and the IC would pop right out without being excessively overheated.
John.

[evingar]

A good technique

A variation of this theme, is to use an electric paint stripper - If you can manufacture a metal funnel so that you can accurately direct the heat, so much the better. Always use it on max heat to minimise the time required to melt the solder.

[XTC]

Or get the solder side hot with a hot air gun or a blow lamp and smack the board sharply on a brick and knock the solder out. It tends to be awkward with large things like long connectors, but works fairly well.

I've also used a solder sucker and soldering iron, but the solder used for flow soldering seems to be higher MP than 60/40 and it helps if you resolder the component with 60/40 before using the sucker.

Pete.

[Sean Williams]

If you dont mind really short legs attacking the solder side of the board with a belt sander will result in loads of reusable components...

Of course this will not work with PTH or double sided/multilayer boards....

[paulsherwin]

Originally Posted by JHGibson

While pulling gently outward, I would apply a small propane flame to the IC pins on the trace side and the IC would pop right out without being excessively overheated.

This is exactly the technique used by third world 'recyclers' in places like China and India. It does free the parts more quickly than using an iron but tends to make a mess and lots of fumes, so is only really suited to being used outdoors.

I have done this with a small pencil torch (£2 from a market stall) in the past and it does work, but I find a big 30W iron is more convenient most of the time. If necessary I blow the solder away with an old ballpoint pen body held in my mouth.

Paul

[Ed_Dinning]

Hi Gents, there are also special soldering iron bits available the look like an IC socket and heat all legs at once. I think they are still in the Farnell catalogue; I have an 18 wat one and it works a treat.

Ed

[Tractorfan]

I managed to salvage an IC stereo amp from a trashed sound card with some long medical tweezers (wifey was a nursing sister) and a plumbers gas blowlamp. Worked a treat.
Mind you, removing a surface mount chip from the component side wasn't such a clever idea as several of the 'lytic caps exploded and hit me in the chest. They were only tiny but they didn't half sting . Don't try this at home kids!
Cheers de Pete

[dseymo1]

Another method is to use a weller or similar gun fitted with a home-made 'bit' of 2.5 sq mm wire (from domestic cable), formed to fit around all the joints to be desoldered.

[fidobsa]

Originally Posted by JHGibson

On occasion, I would have a trash PCB on which there would be some useful ICs or transistors which I wanted to save.
The technique I used was to mount the PCB vertically in a vise, take a firm grip on the IC with a pair of pliers but not too firm that the component would be crushed.
While pulling gently outward, I would apply a small propane flame to the IC pins on the trace side and the IC would pop right out without being excessively overheated.
John.

Could be a useful technique for removing a blown chip too, quicker than cutting the pins and getting them out one at a time.

[backflipper]

The PCB is damaged when this method is used so I wouldn't do it on a something you want to keep.

[dim-bulb]

Hi all,

My method for removing parts from scrap circuit boards needs a fine day outside.

I place the circuit board with component side down on a couple of small blocks of wood to have them positioned off of the work table.

I then take a small butane torch in one hand and my air nozzle connected to my air compressor in the other.

I place the flame over the pins of the parts I am trying to remove, and as soon as I see a molten puddle, in one motion, I quickly remove the flame and give the molten solder a quick blow with the air gun. It's amazing how much solder gets blown away with that air blast.

Once in a while, I need to go over a pin or two or three with a soldering iron to loosen a bit of solder that hung on. Just make sure you're blowing away from you and there is nothing in that direction you want solder splatter on. Most of the time though, the parts will fall out of the hole on the table below it.

This method also keeps the heat to a minimum.

Cheers for now, Bob

[backflipper]

It is also worth while spending a few minutes straightening the pins before trying to heat them, this is especially true when removing ICS.

[davidw]

I use this bit of kit given to me some years ago by an airman at the (long since closed) Bentwaters American airbase. It's 110v 47w.

[fidobsa]

I tried one of those syringe type things for removing solder but never had much success. The rubber end quickly gets damaged and then fails to seal against the board.

[dsergeant]

To use a desoldering tool (syringe) I put a small rubber sleeve (think they used to be called Hellerman sleeves in the old days) over the end. It helps greatly in getting good suction. The rubber sleeves don't last that long, but at least they are cheap. I have no real problems in removing the odd chip (including many with loads of pins), but in my case repair is the reason, not trying to salvage them.

For surface mount devices a hot air gun (Weller portasol or similar) is excellent, though the one I have I can very rarely get its piezo ignition to light it...

Dave

[Jack Spark]

I've trained Mrs Spark to help me with this. She holds an IC extractor on the chip whilst I use a blowtorch from teh other side. As someone said it does trash the PCB but the chips are fine.

She is also a dab hand with the desolder pump and actually looks forward to doing it. I desolder the component(s), then using a pointy soldering iron bit, go through the top, whilst she places the pump on the pad on the other side, I tell her when to press the button and its job done.

Jack

[DAVEHALL]

Originally Posted by dsergeant

To use a desoldering tool (syringe) I put a small rubber sleeve (think they used to be called Hellerman sleeves in the old days) over the end. It helps greatly in getting good suction. The rubber sleeves don't last that long, but at least they are cheap. I have no real problems in removing the odd chip (including many with loads of pins), but in my case repair is the reason, not trying to salvage them.



Dave

That'sthe dodge we used to use at GEC -one other tip from my days at Marconi, was to use coax braiding ,dipped in flux as a cheapo version of solderwick -worked quite well ,though only real way of getting ICs out of multilayer boards without board damage was a solderbath .

[LXSTEIN45]

I have salvaged the odd SMT ic before and done so by sliding a thin enamelled wire under the pins (between body and pads) which is then anchored somwhere on the board e.g. soldered to another component. I take the free end, and whilst applying heat to the first pin I pull the wire away from the chip body. This lifts the pin up ever so slightly, and disengages with solder on pad so I can then work on the next one. I find this method is quite fast and is great where controlled heat might otherwise damage pads or parts! Also all pins remain aligned!

[icecreamterror]

I've had success with a old fortuitous household iron held upside down in a vice like a hot plate, then place PCB on top, and remove IC's and any other goodies.

[Electron]

Originally Posted by Ed_Dinning

Hi Gents, there are also special soldering iron bits available the look like an IC socket and heat all legs at once. I think they are still in the Farnell catalogue; I have an 18 wat one and it works a treat.

Ed

Sounds like a good idea.