WHITE CERAMIC WITH GOLD REMOVAL ??

[oldgoldman]

I admittedly am a rookie in the removal of soldered chips from boards and I usually leave that to others. I have hundreds of the NEC White Gold Ceramics in the picture and need advice on the cheapest, safest, most idiot-proof way of removing these to preserve the value. I liked the post on the Weller Hot Air gun, but $600-$800 seems expensive. These chips will be available for sale .. PM me with offers .. most have rusty top caps .. but Gold is beautiful. Thanks in advance.

 

[gold4mike]

I use a heat gun I bought at Harbor Freight for about $20.00.

 

[oldgoldman]

Thanks !! .. Does it give off a lot of fumes .. should I do it outside .. what protective gear ?

 

[nch]

I use for this purpose butane gas lamp. It is about 10 $ . Also you can use this to glaze meet in some dishes :lol:
Keep in mind that , older boards horrible fumes!

 

[oldgoldman]

Thank you too !!! I'm going to invest in a good industrial fume mask .. set up outside .. have a fan blowing away .. etc. Now .. how in the heck do I grab the chip or will it just fall out with gravity ??

 

[nch]

Small flame, about 3 inches away and hit it hard to ground on a pice of cloth or something ... it will fall apart... You have to do it and you will learn... :roll: or you can sell the boards the wey they are... Nice chips!
good luck

 

[etack]

Its been posted a lot on how to depopulate boards. I've had the best luck with a toaster oven. No fumes unless you forget about it. I heat up the boards whack them on bin most everything will fall out. The chips that are not surface mounted will require to be pried off with a flathead or pluck off with tweezers when hot. If you had a extra regular oven not your kitchen one, one could do a lot more much faster.

Eric

 

[oldgoldman]

Sorry .. I should have researched the forum on de-population techniques. I got all excited !!

Thank you for the advice anyway. When I have my pile, I'll let you know

 

[gold4mike]

I also sometimes use a small electric grill I found at Goodwill for $3.00. I heat the underside of the board until I can move components easily, then grab the board by the edge with a pair of pliers, turn it over and thump it once or twice on the edge of a porcelain coated roasting pan. Most of the components drop into the pan. Give the parts a couple of minutes to cool and then sort them out. The parts don't stick to the porcelain.

Occasionally I find a board that takes an unusually long time for the solder to soften. I believe (but haven't yet tested) that the solder from those boards may contain more silver. I'm saving that solder for future testing and recovery.

 

[Anonymous]

I also sometimes use a small electric grill I found at Goodwill for $3.00. I heat the underside of the board until I can move components easily, then grab the board by the edge with a pair of pliers, turn it over and thump it once or twice on the edge of a porcelain coated roasting pan. Most of the components drop into the pan. Give the parts a couple of minutes to cool and then sort them out. The parts don't stick to the porcelain.

This advice,and the advice for the electric heat gun,is the best advice.Never use a burning heat source as it will almost always catch your pcb's on fire.

 

[Militoy]

I use for this purpose butane gas lamp. It is about 10 $ . Also you can use this to glaze meat in some dishes :lol:
Keep in mind that , older boards horrible fumes!

I'll bet older meat would give off horrible fumes too! :mrgreen:

I know it isn't a big issue when desoldering only a couple hundred gold-plated chips from PCBs - but one issue to consider if you are doing this kind of thing on a regular basis is how much gold is actually alloyed into the solder on the PCB. We solder gold-plated chips into PCBs on wave-flow machines, and dip gold contacts into a solder pot at work on a regular basis. We have to monitor the Sn63 solder alloy on a regular schedule for contaminants - and one contaminant that we regularly have a problem with is gold. The gold plating on a solderable IC or solder pin is there to protect the solderability of the contact surface from oxidation. Much of it is typically shed when it is soldered. Just another thing to consider when planning your recovery strategy, if you are working on a commercial basis.

 

[Smack]

When I want to depopulate stuff off boards I use a fresnel lens, it's free of cost after the initial investment. If I remember right, mine was 54 dollars. Down side- kind of hard to use outside during winter.

 

[Smack]

BTW a safty note: DO NOT leave this type of lens lying around in sunlight, you will catch stuff on fire. They are not a toy.

 

[patnor1011]

What is the maximum temperature which can be achieved with this lens?

 

[Oz]

It depends on the lens. In exceedingly rough terms the sun provides close to 1kw per square meter. How big is your lens and how tightly are you focusing it? It is like asking how hot of a spot can you create with a generic magnifying glass, it depends on the magnifying glass. Having said that, I do know of a guy that was melting aluminum with Fresnel lenses.

 

[Smack]

It depends on the lens. In exceedingly rough terms the sun provides close to 1kw per square meter. How big is your lens and how tightly are you focusing it? It is like asking how hot of a spot can you create with a generic magnifying glass, it depends on the magnifying glass. Having said that, I do know of a guy that was melting aluminum with Fresnel lenses.

Just what I would have said...thanks. Mine was advertised to reach just over 700 F. A piece of wood will flame in about 5 seconds. There are two general types, a linear and a spot lens. I bought the linear lens to have a larger and more rectangle focal point. Then I got a rear projection 50" tv for scrap and kept the fresnel lens off it, this one is a spot lens and will interchange with my linear in the frame. There are also solar grade lenses but I'm not sure of any difference, the bottom line would be focal point size and temp. I would think.

 

[oldgoldman]

So I Bought the Harbor Freight $19.99 Heat gun and a swivel vise . .and spent an hour or so on these..

Technique and tools need some fine tuning. Need to mitigate the fumes better, but I was happy with the outcome. I think I'm addicted to re-flowing solder now !! Thanks to all for the advice.

 

[oldgoldman]

Here are the other NECs .. these came out like butter

 

[oldgeek]

So I Bought the Harbor Freight $19.99 Heat gun and a swivel vise . .and spent an hour or so on these..

Technique and tools need some fine tuning. Need to mitigate the fumes better, but I was happy with the outcome. I think I'm addicted to re-flowing solder now !! Thanks to all for the advice.

Fine tune your process, and try not to break them apart. The fine solid gold wires that connect the die to the carrier are lost easily when you break them open like that. IMO

 

[aflacglobal]

Those boards look clean around them chips besides a couple of capicators sprinkled around them. I have used tin snips to trim cut the boards into smaller strips or pieces which helps to remove unwanted material beside what you are trying to extract. Break the caps off and put the pieces of boards in some plain hcl ( No air or H2O2 ). In a day or so the chips just fall out with clean legs ready for the next step. Using heat you are still not removing all the solder which will carry over to the next step. Just a thought