Gentle way to remove gold plated ic chips

[razzel8]

Hello all,
In my search for fingers and pins i have been running across some really nice old gold plated ic chips. I like these so much i don't want to destroy than but rather save them to collect. I am looking for a way to remove them from the circuit board without harming them to much. There are various methods on here mentioned but i haven't found one that didn't damage the fragile pins in some way.
Anybody got any idea's? I know these chips will probably never have any value higher than the small gold content but i really like them and have enough fingers to mess with.

Thanks
Raz

 

[rewalston]

The easiest way I can think of would be to de-solder them with a soldering iron and a little added solder, then use a solder sucker to pull off the molten solder. Or you can use a heat gun on the back side of the board, but that would loosen other components as well.

Rusty

 

[razzel8]

The problem with desoldering is I can't get all the pins at once and even with a solder sucker on each pin a small amount remains that clinges as soon as heat is removed. I thought that method would work at first, with a small flat screw driver, to lift it out of the socket but they are just to close to get enough clearance to gradually lift the complete chip out.
Thanks
Raz

 

[Geo]

if you want to reclaim the chip without damaging the chip, use a heat gun to warm the board. if the chip is all you are worried about, the board can be heated until it turns black and it still will not damage the chip. heat the board and turn it over and tap it gently to loosen the chip.

 

[maynman1751]

Have you tried solder wick? You can probably get it at Radio Shack or a similar type store. It's simply a copper mesh 'lace' that will draw the melted solder from the joint. I used it when I was doing electronic assembly on military systems at Lockheed-Martin. It works very well.

 

[razzel8]

Thanks Geo
That's sort of the method I'm currently using. However, I think I may be heating the boards too hot because I am getting a smell I can only describe as a cheap brand new water hose. Is this toxic you think?
Raz

 

[jimdoc]

Is this toxic you think?
Raz

When in doubt, always treat it as if it is.

Jim

 

[Geo]

yes it is. not deadly but enough to cause some irritation to your mucous glands. use a fan blowing sideways to your work in a well ventilated place.

 

[NobleMetalWorks]

If you do a quick search on eBay, in the vintage computer area, you will find people selling those types of chips, there are a lot of people who collect them. You might be able to sell the boards you have, with the chips on them to people who do this on a regular basis and are equipped to remove the chips, and then purchase with that money, the chips you want to collect.

Here is a link to a chip being sold for a crazy price.

http://www.ebay.com/itm/AD572SD-883...925?pt=LH_DefaultDomain_0&hash=item35a4ffc7bd

You are not going to get that kind of price on the chip you have on that board, but sometimes you can come across chips that are worth a lot to collectors. I check with people I know before I throw them in the ball mill to be processed. I have a few customers that buy collector chips from me, when I run across them. If you establish a good relationship with a few of these guys, some will be more than happy to explain in great painful detail the method they use. I was told by one guy that he uses acid in dropper amounts to eat the solder away so that he can remove the chips without damaging them.

If you still want to remove them yourself, Goe is right, the heat gun is the best way I personally have found, to remove the chips without causing damage. And he's absolutely right about the PC board turning black, but still not harm the chip itself. He's also right about the fumes, you should do this in a well ventilated area, or preferably, with a soldering fume extractor. I would practice on some regular IC/Prom chips before I tried anything with the one you want to save. I have also used a propane torch in the past, keeping enough distance from the board so as not to damage the chip but that takes some practice, the heat gun is still the best way.

 

[razzel8]

Wow Sbrown!
I hadn't realized they got that high. A google search had turned up just a few people that had a bunch of popular ones.
I had already removed a different one from a board and was just getting ready to ask if anyone knew the best way to remove the solder off the ends but I'm going to have to research these out more. It would be nice to sell the whole board on the extra ones I have but I'd like to have a nice little collection of some cool ones.
I don't even know the condition collectors of these want, as I didn't realize anybody really saved them.
The chip on the right is the one I removed. The one on the left has never been soldered.
Sorry I'm so off topic I'll try to stock to refining topics.
Raz

 

[macfixer01]

The easiest way I can think of would be to de-solder them with a soldering iron and a little added solder, then use a solder sucker to pull off the molten solder. Or you can use a heat gun on the back side of the board, but that would loosen other components as well.

Rusty

That's also how I always removed chips I wanted to preserve. Adding a little new solder to help melt the original solder and using a solder sucker works quite well. On Ebay there are some very cheap Chinese knockoffs of the classic blue and yellow Solder-Pullit tool. They work fairly well but one minor annoyance is the tip doesn't fit tightly enough into the barrel so it gets pushed out of place occasionally while re-arming the vacuum spring. Multi-layer boards require extra heating so are a little slower going (mainly on the power pins that also connect to the inside layers). For smaller DIP packages (14,16,18,20 pins) I picked up a nice used tool for cheap on Ebay. It's a dual soldering iron which opens and closes like a pair of tongs or tweezers. The ends have a pair of angled blades which can apply heat to multiple pins all at the same time. So say on a nice 4116 gold topped memory chip I can heat all the pins at once on the solder side, and on the component side of the board just grab the chip and pull it out with an IC removal tool.

macfixer01

 

[glorycloud]

Here is the easy way - use Mr. Heat Gun. 8)

Flip the board over and heat the bottom of the board where
the chip is until you see the solder melting around the pins.
This may take 45 seconds to over a minute depending on how
hot your heat gun gets and the thickness of the board itself.
You want to heat the board but not burn it or cause it to smoke.
(Obviously, this should be done under a fume hood or outdoors!!)

I use a snall flat head screw driver to lift the chip I want off
the board without bending or breaking the legs if it is a collectible
chip that I want to preserve.

I use heat resistant gloves and eye protection as well. 8)

 

[lazersteve]

I always use a good temperature controlled pencil soldering station, solder wick, and plenty of rosin flux to remove ic's delicately. Work around the outside edge of the ic on the top side then desolder the bottom side as well.

The rosin flux cleans up easily with denatured alcohol and a cotton swab.

Steve

 

[Pally]

I use a propane torch for fast removals....i simply heat the backside and tap the board against the front side when the solder gets soft.
I use a fan to carry off any smoke or stink....
I strip whole boards this way, its fast and efficient as i am not really savoing anything for re use....just scrapping.
I use a plastic tub half full of water to catch the units that fall out.....
Im new at this so any dangers that may be encountered im not aware of other than the acrid smoke
You can generally get the stuff off before it burns the board but it does get blackened.....

 

[Anonymous]

I use a propane torch for fast removals....

That would be a bad decision for this situation.
A heat gun is the best method.

 

[butcher]

If done properly a propane flame (regular hand held torch, and smaller butane pencil torch and solder iron), can remove Integrated circuits (I use a tool made to grip and pull the IC when solder just melts) and other electronic components, so that these components can be reused, even very heat sensitive components like transistors can be removed (pencil flame and hemostat as heat sink),

Another trick add a little solder to each leg then make this into one big a blob of new solder, now the solder iron can heat several legs at once allowing you to pull out the part with your gripping tool, this blob of solder can be moved to the next component you are after,

Also a soldering iron and solder sucker, or wick works great, at one time I had a solder station that had a small vacuum pump and tips with a hole in the center or the iron’s tip, a great tool (expensive),

Another thing I will do some times is cut the circuit boards into small square, cutting up close to the device, this allows me to separate components, which can be de-soldered later, with this I can sometimes clip off the circuit board right next to the devices leg, making removal of the circuit board from the device easier,

I part a lot of circuits for reusing the components, and use an arsenal of tools to remove these components, most of them have been mentioned in this thread, also I use a variety of very destructive methods to remove components from circuit boards (if these components will be destroyed any way).

 

[Moo]

I agree the best cheapest method is a heat gun for sure, however if your stuck to using a soldering iron make sure you use one with a flat tip and not one of those little pointy conical tips because you wont get any heat transfer to the solder also use a tempreture controlled station cranked to about 390 celcius those cheap plug in to the wall irons are garbage and lose heat quickly be sure to clean the solder first with isopropyl alchohol before attempting to remove it, this will clean any junk off so its not hard to melt the solder adding a little to the points your trying to desolder will aid in helping it to flow again as well. there is a substance on the market called chipquik which helps sometimes when you want to remove a 32 pin eeprom/IC by keeping the solder molten for an extended period of time. If you wanna remove a socketed eeprom you can just pry it up gently from each side or use a chip puller. Other automated methods do exist but there not cheap.