Heatgun Desoldering

Using a Heatgun to remove/ scavange parts from old or broken PCB.
I using a old harddrive as a example. You can salvage most any surfacemount, BGA or even through hole parts using this method.

Step 1: Remove the PCB from anyother casings.

First remove the PCB from any casings.
Here I have just a few screws to remove.

Comments

[ratgod]

Excellent instructable,
I use this method on a regular basis, my biggest sugestion is that you wear safety glasses.
Heating a PCB too much will cause the board to delaminate and the resin can boil and burst through the board sometimes, In my early attempts I have also had an electrolytic cap burst on me, nowerdays I rip them off before hand (unless I really want them, then I would desolder the old fashion way).

I usually stand my heatgun on the desk (mine has a flat back so I can do this), then I will prop the circuit board about an inch or 2 above the heatgun while its running then I will pick the components off in the area then move the board quickly before it delaminates. Another method is heating the board in this way then hitting the side of the board agains the desk or a brick so all the reflowed components come off, the only downside to this method is that you have to clean the globs of solder off afterwards.

[fdsafdsaqwrewqrbsafdsagrgew]

Agreed. Out of all the methods I've tried so far, my heat gun seems to provide that balance between efficiency and safety that you just cant get with a desoldering braid or (at the other end of the spectrum) a butane torch. Air guns are cheap, don't need anything more than a standard ac outlet to run, and have a nice area of effect to help pry off even the largest chip.

[pinkhairkid]

thanks a million I've been trying to get a flyback transformer off of a circuit board for weeks

[hitachi8]

45W++ soldering iron and a desoldering pump. not that hard...

[mage2]

Glad i could help everyone with this. I plan on having new instructables sometime in the near future.

[dudeu]

most parts can stand excessive heat for short periods. Resistors,caps,diodes. Ic very sensitive. Heat guns may work but any temp over the temp to melt solder will effect components. Solder melts 160-180 deg. 
 

[dentsinger]

Why can't you heat it from the back side and let the components falls out? Just curious since I'm wanting to clear away components from boards en masse for art.

[mage2]

You could for some componets but with the amount of heat you might toast (burn) the side the heat is on PCB is not very conductive so be wary of heat buildup.

[denilsonsa]

I've never done that, but I read somewhere on the Internet that we can (or should?) heat from the back side. Then, the component will just fall off.

[rocketman221]

i have done that before with a pencil torch and it seems to work alright.

[dentsinger]

Actually I wasn't thinking too smartly when I made that comment about why not heat the back side. Surface mount components have the solder on the face of the board. Since then, I did get my self a heat gun, but the board would scald and start smoking before any solder would run.

[awang8]

Funny, the board is made out of fibreglass and copper. Make sure it doesn't have a protective layer which is usually plastic that melts.

[MichealY]

Thanks.

[Patented]

Nice method!

[wethecom]

if you superglue somthing to the part being removed you can create alot of pull to remove smaller to handle parts dosnt seem like a bad idea and thanks for the tip

[BFeely]

Parts are often glued to board if they are on the underside.

[mrmeval]

You can achieve better control with this.
It's a Weller heat gun designed for reflow soldering and desoldering. It comes with restrictor/reflector tips for various uses.

Ow, I did not realize how expensive those are! I use them at work.

The bigger ones work and we have those too. They're variable and come with a similar restrictors and reflectors.
Something like this
heat gun example

As to heat effecting the parts most can take the heat of reflow for so many seconds. Get the right heat on the part, get the part off and then let them cool.

Use ESD protection or a lot of them will die, some instantly some may take weeks. Some will fail with weird symptoms, intermittant, wrong output levels, etc.
http://en.wikipedia.org/wiki/Electrostatic_discharge
http://www.cisco-eagle.com/storage/safety%20and%20ergonomics/mats/esd-mats.htm

I think Rat shack has a kit but you can find cheaper.

[Kegtapper]

Looks like the $34 one at Amazon is for heat shrink tubing, not SMT soldering/desoldering.

[OmnivoreNZ]

Someone (can't remember where) suggested working over a container of water. I hold the board upside down and heat from above. Parts fall off, land in the water, and cool down immediately. Very few components are damaged by getting wet. Only big problem is my wife *hates* the smell - I have to have a shower and change before she'll come near me.

[tomyu]

I saw crazy desoldering in
here.
(Original page is written in Japanese. This link is linked to automatic translator.)
He puts the PCB into cooking-pan filled with hot cooking oil, and scoops detached surface mounted parts.
Caution: If you try this, remove the aluminium electric capacitor before you try.

[technodude92]

if you try this I recomend that you use mineral oil. Mineral oil will not go rancid and is used in electronics regularly(high voltage xformers etc.)

[RaNDoMLeiGH]

Now that is a clever idea. You'd probably want to use a pan that you DON'T use for cooking (lead/mercury poisoning and all that). Will the oil do icky things to the components? And does it get off all the extra solder? I have a LOT of things I've been saving to desolder bits and pieces from (telephones, alarm clocks, and also to use the PCB for crafty) and that would really be a time-saving way to do it.

[uzerzero]

Something tells me that those parts probably smell like burnt plastic, and that they probably don't work. Still though, that's a creative idea for desoldering surface mounts.

[tomyu]

Sorry, I could not make proper link.
Please enjoy original page.
http://www.paken.org/aaf/fried-board/index.html
(There is link named 'Rough English Here' which is linked to automatic translator.)

[mightywombat]

Most of these board from consumer electronics are soldered automatically by passing the "stuffed" board through an oven. The parts are pre-tinned (their contacts have a little solder on them) and are placed on the board by a machine, to get the placement just-so. Then the board rides through an oven where the solder that is on the components melts just enough to fuse to the pads on the board. My point is this: chances are that if you are only heating up the component enough to cause the solder to melt (reflow) then you probably aren't getting the component any hotter than it got during the production of the board itself. If you're *really* curious about the heat tolerances of a part, try looking up the datasheet online and see what the maximum temperature the part can stand is. If your gun gets hotter than that, you are risking the chip, but if you can set your gun to a lower setting and still melt the solder, the component should be fine.

[jok]

I once i used my hot air gun (aoyue 909) to reflow a circuit board it had this farad capacitor it blow up witha loud bang. so be careful when heating around the area filled with capacitors.

[ghostrider157]

you can actually take this idea to fix an Apple G3 iBook. one of the main issues with those laptops is a bad logic board, because the video chip wouldn't make a clean connection. If you take the bottom case off and the bottom shield off, and then just heat the snot out of that chip without touching or moving it at all, 9 times out of ten it fixes the computer

[dfowler7437]

I have an article and some pages devoted to heat gun scrounging. The following link leads to a How-To and FAQ section and a post about scrounging a rack mount router.

http://www.uchobby.com/index.php/scrounging/

[mage2]

Some parts are more sensitive to heat than others. If you are quick about it you should not have any problems. I have not had anything fail so far. But I have not tried using this method on anything that was really sensitive. I do not let the parts get any hotter than I have to to let the solder melt so that I can lift the part. If you smell burning plastic and the part is still attached then you have got it a little to hot and the part is glued in place. I was using a Harbor F Heatgun, It cost me about $10. It works for me.

[HamO]

Good Instructable (we need a shorthand for that), just don't do this near the smoke detector. I set off the whole building alarm once.

[MD_Willington]

I've also seen this done with a used electric skillet, the type that you set on the counter and plug into a wall socket, works well for reflow work too.

[mothflavour2]

Wow, I'm going to bave to get a heat gun to try this. By the way, do you know if the heat adversely affects any of the parts?