how to desolder opamps

[changes]

sorry if this has been covered before but is there any info on how to do it the right way?

[RLBJR65]

If it's a rare chip I hold a damp cloth on it to keep the heat down.
Get a desoldering wick, something like this.
http://www.computronics.com.au/multicore/wik/

Or use a solder sucker, there are several types.
http://www.wassco.com/quicremofsol.html
http://www.mpja.com/category/Solder_Equipment/COMPACT_SOLDER_SUCKER_0041_TL.asp

IMO good wicks are the best.

[MartyMart]

Use wick/solder sucker one "pin" at a time and leave about a minute between the next "pin" - shouldn't overheat then .... BTW be quick !!

Marty.

[Mark Hammer]

Optimal method depends on the state of the solder-sucker and the board.  If the solder sucker has a very precise tip and you have some room to work on the copper side, you CAN often get in there and zip-zip-zip it's clean.  If the solder-sucker tip is blunted and the to-be-desoldered pins are crammer in tight with too many other things, it is hard to place the requisite suction where needed.  In those instances, solder wick is wonderful.

I get best functioning of solder wick when I spread it out a bit so it can fit like like a sweater over the head of the IC pin (i.e., the pin sticks up through the solder wick).  A bit of liquid flux on the solder wick supercharges it.  If the chips in question happen to be on a double-sided board solder-wick is pretty much your only choice.

Sometimes an added daub of solder to the joint will allow the solder to flow more readily and makes removal via sucker or wick somewhat easier.

As R--------5 notes (jeez I hate handles you can't easily use like a name :?   sorry, just my weakness), keeping a lid on heat is a great idea.  Official clip-on heat sinks are great but a small wadded-up piece of wet bathroom tissue or paper towel serves nicely in a pinch.

[nosamiam]

If I can't get a soldersucker in there, or even if I can and there is just a little bit of something holding the IC/socket in, I will wedge a small screwdriver under one end of it.  I butt the end of the screwdriver against the table.  Then, holding the board with one hand and the iron with the other, I quickly touch as many of the pins an I can in rapid succession to heat them all up a bit.  While doing this, I apply gentle downward pressure on the board so that the wedged screwdriver pries the opamp up.  You have to work fast so that the chip doesn't heat up too much and so that all the solder melts before the first pin you heated cools off.

[Paul Marossy]

If the chips in question happen to be on a double-sided board solder-wick is pretty much your only choice.

Yep. And even then, it can be a PITA getting it out of there.

[Mark Hammer]

I find that flowing a bit of solder onto the component side of a double-sided joint is a good idea too.

Whatever you do, make sure you can wiggle all the IC pins freely before attempting to remove the IC.  Few things more frustrating than trying to harvest a much sought after IC from a used board and having it rendered unusable for the sake of a single pin left fractured on the board.

[Jason Stout]

If you don't care about the IC you're removing just cut the legs off! (a Dremmel cut-off wheel works great) Then remove the remaining bits with the help of a solder wick and some flux.

[Paul Perry (Frostwave)]

Jason is right, the main question is, do you want to save the chip? (hint: if the chip is worth less than $5, the aggro is not worth it, if it is a double sided board).
My favorite tool for rework, is a stainless steel dental pick (I think AllEctronics has them? or was it Goldmine?). The idea is, once you suck or wick the solder away, you can use the pick (to which solder will not stick) to wiggle the leg, so as the solder cools around the leg, the leg doesn't reattach itself to the side of the hole.
And once the chip is out (with or without its legs) you can heat the hole up & shove the pick thru it, let it cool, then pull it out & there is the hole, with no solder in it!
removing a chip from a plated-through hole........ no fun at all! :x

[R.G.]

Lecture #43: Removing IC's from PCBs

The first thing to do is to decide: can you sacrifice either the IC or the PCB you're removing it from? If yes to either one, your life is much easier.

If you can sacrifice the PCB to get a good chip, then chuck the PCb edge-up in a vise, get hold of the IC on the component side with a chip puller or pliers at the ends of the chip body, and wave a lit propane torch over the solder side from about 3" away. Gently. The pins all hit soldering temp at the same time, and the chip comes ... whomp... out of the board. You may and probably will burn the PCB. Chances of success: 80-99%

If you can sacrifice the chip to get a good PCB, then clip the leads off the chip on the component side, and use a soldering iron to lift each lead out the component side one by one, then solder-wick the holes open. I drew up cartoons on how to do this at GEO, from years ago. Chances of success: 90-100%

If you simply must have BOTH a good chip and a good PCB when you separate them, use solder wick with a good, hot iron. And pray. When you get the holes all wicked out, the pins will still be stuck, so wiggle each pin with a dental pick or needle nose pliers until the pin comes loose in the hole. If it won't come loose in the hole, refill the hole with fresh solder and rewick it dry. Chances of success 30-75% (That's for me, and I've been soldering for over 30 years. Your results may vary.)

[aron]

I remember this contribution a while ago. Thanks R.G.

ARCHIVE

[DavidS]

There's another method, from the "chip-can-die-but-the-board-must-live" camp :)

I figured this one out when my father had torn apart the VGA connector on his motherboard (onboard video...ugh) by just tugging on the computer with the monitor cable still threaded into it... He was a Nuclear Engineer for the Navy, but for some reason, he still routinely did weird shit like this...

Anyway, I still had a shitty Radio Shack iron at the time, and desoldering through-hole plating on a 4 or 6 layer board was just NOT going to happen.

So, I clipped off the connector and drilled out the through-plated holes with a tiny bit I used for drilling out homemade PCBs.

Worked just fine on a motherboard! System worked great after that.

Too bad Dad still couldn't figure out how to use the computer.

[TheBigMan]

I use wick and allow a minute or so between legs, for each leg to cool down and to make sure the iron is at maximum temp to minimise contact time.  It's worked for me so far, but on the other hand I've done this to around a dozen Tube Screamers, and despite the fact I've never killed an opamp those Toshiba ones aren't going to get any use any time soon.  

[Paul Marossy]

I used the "cut the pins" method when I repaired my ART X-15 MIDI footcontroller a couple of weeks ago. If you want to save the chip, it gets harder to do successfully.  :?

[Processaurus]

Cutting the legs off the IC is a good technique for saving a board, your sanity is worth more than an opamp...

[grapefruit]

I definately agree that for double sided PCB's the cut the pins and pull em out approach is the easiest. Just wanetd to add that if you need the chip and the pcb (or an easier way to just save either) you can use some stuff designed for desoldering SMD. The stuff we use is called "Chip Quick". It's a low melting point solder. You just put flux on the solder joints then mix the chip quick solder in with the old solder (remove some of the old solder first if there's heaps on there - usually not on a flow soldered pcb). It will easily keep 8 pins molten long enough for the chip to drop out. Just make sure you remove all that solder before re-installing the chip. The stuff is not cheap though.

The cut the pins approach applies to anything on a double sided PCB. I've chomped through many a connector with my side cutters to isolate the pins and pull them out. Multipin connectors, RCA's, Jack sockets, Pots, especially stuff where you can't get to the top layer. You still have the fun of getting the solder out of the holes, which can be fun if there's a ground plane on both sides.

Also, if you need to remove components like resistors or diodes from double sided pcb's, the easiest way is to heat up one pad, pull that end of the component out with pliers, then do the same for the other end. Easy. Then you'll have to remove the solder from the holes. If it's something like an LED or electro with the pins close together just put the iron accross the pins so they both heat up at once then pull the component out. You may be able to get the new one in the same way, without clearing the holes.

Stew.

[Paul Perry (Frostwave)]

That's a good tip on the 'chipquik' stuff, Grapefruit! it's usually used with surfacemount rework (it is the only time you are GLAD smt is so small, because youneed less expensive chipquik!). the key is, not only is it low melting point, but unlike solder, it is designed not to freeze suddenly, it is kind of mushy.

[scott5678]

I wanted to say thanks to all the posters on this topic, I used a lot of the advice recommended here in the production of this 'how to' desoldering video.