# south bridge heat spreader wires



## Geo (Mar 29, 2012)

i wet ashed one heat spreader to get a better idea of how much gold could be expected.

i didnt get a weight because i have really sucky Ebay scales.but the amount of wires is impressive.



heres a single wire.


these are from the black heat spreader, not the green base.


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## martyn111 (Mar 29, 2012)

Good info, well presented, Thanks for that Geo, that will definately be considered next time I use Patnor's black chips process.


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## patnor1011 (Mar 29, 2012)

martyn111 said:


> Good info, well presented, Thanks for that Geo, that will definately be considered next time I use Patnor's black chips process.



Well I am honoured by that naming of process. 8) 
I must say that I started thinking about how to do them when I saw Rusty`s experiment and NoIdeas board incineration. I did what I did after some discussion with Sucho and it just happened that I have reported my experiment process here with pictures. Anyway I am glad it makes people to think more about black IC chips packages and with our collective input we only will make it better and better.


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## joem (Mar 31, 2012)

Are these sold or plated gold?


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## johnny309 (Mar 31, 2012)

Hope this will help.....sizes and everything :

http://www.qsl.net/ct1dmk/wire_bonding.pdf


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## Geo (Mar 31, 2012)

there is only two types, Au and Al.so that narrows it down quite a bit. the gold color indicates that its gold, too the thickness is less than a human hair. the reason i think these are so cool it, with the IC's and flatpacks, theres a copper frame that has to be dealt with. with these heat spreaders the gold wire has no other metal contamination. i used my oxy/acet torch to heat a dozen to almost white hot. it took a couple of seconds each and then powdered the base with a mortar and pestle.then i put them in a coffee pot and added a drop of dish soap and set in a catch pan in the sink. i filled the pot and cut the water to a thin stream and let it run till the water in the pot was clear. then gently poured the water into the pan and dried what was left. i remove the silicon wafers and ground again and repeated the rinse.


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## jmdlcar (Mar 31, 2012)

Geo how many flatpack was that? To me it looks like there more gold then I though.


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## Geo (Mar 31, 2012)

Jack, thats not flatpacks. look at the picture in my first post, its from the black part thats on the green fiber base. they are called north and south bridge chips on a computer mother board. theres gold on the green part and the wires are in the black part. that amount came from 12 of various sizes.

sorry about that Jack.


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## vango57 (Apr 8, 2012)

I pop these off of all boards I process and have several pounds of them. Have not processed any for gold but felt they were worth saving.
I took an old stanley chisel, sharpened it slightly on my grinder. I use a pair of old wire cutters as my hammer to have a good weight balance and a couple of hits and these just pop off the board, sometimes they come off in one blow but I have learned that the right weight for whatever you use as a hammer has a direct affect on the ease of removing them. An actual hammer is too heavy so finding that balance makes the job much easier because you have to hold the board on its edge and the chisel with one hand and use your "hammer" to knock it off. ALWAYS wear glasses or safety glasses as the ceramic often flies off and a piece in the eye would not be comfortable.


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## zenophryk (Apr 8, 2012)

I tried the chisel method. but it was breaking them too much, so in order to get them off in one piece I now use a paint scraper. I found a very thin flexible paint scraper where the "tang" extended all the way through the handle. I then sharpened the end on a belt sander. it slides under most anything on the boards with just a few taps from a pair of pliers.


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## Geo (Apr 8, 2012)

after i have the green base off the board.i use my heat gun to separate the heat spreader off the green base. if you just rip them off without heat, you will pull the gold plated traces off the green base. when you heat the black part, the glue breaks its bond and the heat spreader comes loose very easily. i also scrape the solder off the back of the base while removing the heat spreader. it makes it easier to process the green base later. i havent checked the legs to see what they are made of or if they may be plated with gold or not. i know they are just small dots of metal, im assuming they are copper because when i heat the solder, the legs remain solid.


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## goldsilverpro (Apr 8, 2012)

Geo,

You're getting pretty damned good at this stuff.

The only thing I know about these is what I've learned on the forum. Some questions:
(1) Is the purpose of the heat spreader to replace a heat sink?
(2) Are the wires solid gold or gold plated copper?
(3) I assume they are locked into the plastic and not connected to anything electronically. Is that true?
(4) In the last photo on your first post, there is one wire. Can you mic it or is it too small? What is it's length? What is that thing on the end and what does it do?
(5) How many wires per unit?

If the only function of these is to distribute heat away from the chip, pure copper would work at least as well as gold. Unless the wires are so thin that it would be cheaper to make them from solid gold, rather than plate them, I would guess they are gold plated pure copper.


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## Geo (Apr 8, 2012)

thanks GSP, that means alot coming from you.ill tell you what ive learned.

1.the heat spreader contains the silicon chip and the binding wires.some of these chips have a heat sink and some do not. the spreader is not ceramic nor is it plastic.it is organic because concentrated sulfuric will break it down though it is very heat resistant.
2.the bonding wires are made of either solid gold or aluminum.if you can see the wire and it looks gold, then it is gold.i dont have the means to mic one wire but it is less diameter than a hair.(i made a side by side comparison)
3.the wires connect to the silicon chip embedded in the heat spreader.
4.they connect with the small ball at the small end of the wire to the chip.the wide end bonds to the gold plated pad on the green base.again, i cant mic it and couldnt find anything small enough for a side by side comparison.
5.ill post a picture with one of four sides. i didnt count the wires but if you multiply by four it will give you a good estimate.the wires are in pairs.



heres a different view of a single wire that shows the ball at the end.


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## samuel-a (Apr 9, 2012)

Chris, see my post "Black IC's - a look inside".
You can find high rez pictures of wires and wafers and more info regarding your Q's in the tutorials section under "Processing Black IC's - The wet way".

As Steve says, nothing new under the sun anymore... 8)


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## zenophryk (Apr 9, 2012)

So these IC packages are refered to as BGA (ball grid array) packages. http://en.wikipedia.org/wiki/Ball_grid_array and the pins are indeed solder balls. I have read elsewhere that they (the solder balls) contain a higher than average (for solder) percentage of silver, which may be why they aren't melting with the rest of the solder. 

So you're calling the black epoxy top of the chip a heat spreader? is that actually what it is? it seems to me to be just the silicon wafer with the gold bonding wires. I would expect a heat spreader to be some sort of iron, aluminum, or copper based square designed to take heat away from the wafer and help distribute it to a heat sink that may be mounted above the chip. So I don't think these southbridge chips even have one. Which is cool cuz there's less base metal to deal with the epoxy/plastic black top is only there to hold the wafer and keep all the bonding wires inline and protected. 
Not trying to be a know it all, just regurgitating other things I've read and maybe able to fill in some gaps. I have a few pounds of these that I havn't dug into yet.

I'm going to try a heat gun. do the tops just pop off or do they still need a little help when you heat gun them?


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## Geo (Apr 9, 2012)

check this link.the term heat spreader is correct when it refers to the top of these chips.

http://www.minteq.com/our-products/minteq-pyrogenics-group/pyroid-ht-pyrolytic-graphite/

the top lifts at the corners. i use a knife blade to lift them off.


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## samuel-a (Apr 9, 2012)

Geo

Actually, in the link is a product made of graphite sheets that are held by thermal grease to the plastic package.
Sometimes, the same arrangment is done with Al foil.

In some high end applications, the graphite sheets (heat spreader) replace the thermal grease altogether, and an aluminum heatsink is screwed to the component/cpu.
In my mind, the epoxy material sole purpose is to hold the wafer and wires together and be able to withstand the heat generated by the resistance, although it does act like a heatspreader (like every object exist), Plastics/resins/epoxy are known to be bad heat conductors. That's why, for the most part, an heat sink is attached to n/s bridges.

I have several graphite sheet, i'll upload a picture later today.


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## devo (Apr 9, 2012)

Just wanted to say thanks for those awesome pictures. I have no idea how you guys get those, but they always impress me.


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## goldsilverpro (Apr 9, 2012)

As I understand it, pure gold bonding wires are usually one of three different diameters: .0007", 001", or .002", with the first 2 being the most common. At a $1645 spot, here's the dollar value of each, per inch of length.

.0007" diameter = $.0066/inch
.0010" diameter = $.013/inch
.0020" diameter = $.053/inch

A tr oz of .0007" Au wire is 4 miles long.
A tr oz of .001" Au wire is 2 miles long
A tr oz of .002" Au wire is 0.5 miles long

I think I read in several places that the wires on these were 17 to 20 microns thick. That would put them in the .0007" class above. It would be interesting to measure them, though. Anyone have a good optical comparator? Or, a wire could be cut to an exact length and weighed. It would require at least a 5 place balance, though, to get any accuracy at all.

As usual, please correct me if my math is wrong.


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## Geo (Apr 9, 2012)

thank you Devo, i have a set of lens that i use with my camera. it lets me focus in on some very small stuff.

Sam, lets try a patent this time.i know you know more about this stuff than i do because you have spent more time dealing with it and im not trying to be difficult, just thorough. 


http://www.freepatentsonline.com/6552907.html

Abstract:
The present invention is directed to a heat dissipation structure for an integrated circuit package, comprising a thermally conductive solid layers, one of which has receptacles for holding a thermally conductive flowable material, the heat dissipation structure being placed between the electronic component and the printed circuit board. The present invention is used advantageously with a primary heat sink placed on the top side of the integrated circuit package away from the printed circuit board. The heat dissipation structure preferably hemispherical balls on the package side of a high heat conductive plate to improve heat transfer from the die to the integrated circuit, especially, BGA, substrate to PCB power planes for heat dissipation and leads to improved secondary heat transfer from IC die in BGA packages to the heat spreader power planes in the system PCB. The heat dissipation device allows retro-fit of the heat transfer/transfer mechanism or primary attachment.

it is also referred to as a "heat dissipation structure" but heat spreader was also used and is shorter to type.


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## samuel-a (Apr 9, 2012)

Geo

Since the subject brought up and you supplied a link, i though i'd share what i know (or think i know :mrgreen: ).
Though it might seem that way, i did not ment to be petty and i apologize if offened you. 

I think it all comes down to terminology, as long as we all understand each other. Nither us or a scientist who write patents are bulletproof when it comes to writing/pronouncing mistakes.

On a side note, I do agree that the package material does somewhat act as a heat spreader, very much like all other materials on earth that absorbe and emit energy. Some are better heat conductors then other, like metals and graphite/diamond. Plastics and most organic compounds (solids) are bad conductors of heat, so it's hard for me to imagine the sole or main purpose of the packing material will be to spread heat (thereby naming it a "heat spreader").
As far as i know, the professional literature relates to the Epoxy+Resin as "Package Material" or "Mold Material" and the entire composition of these materials are considered proprietary information.


p.s. - here's the picture of the graphite sheet. it used insted of theraml grease.


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## Geo (Apr 9, 2012)

no apology needed. since i started reading about these things, thats the description that stuck in my mind and ive referred to them that way ever since.i have no other term to describe them other than "that black flat piece on top of the green flat piece" :lol: after members read this topic, they will know whats meant when they are referred to as a "heat spreader".


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## zenophryk (Apr 9, 2012)

So I'm wondering, once the top black piece is seperated from the bottom green piece, it looks and sounds like the only materials in the top black piece is the silicon wafer, the bonding wires, and the resin encapsulation. There's no Iron, or copper or anything else right? So if I were to incinerate a bunch of the black tops and crush that up there should be no magnetic material right? So couldn't I just throw it in some AC solution and disolve the bonding wires? is the ash going to cause much of a problem with AC? I know it would with AR. 

-Z


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## patnor1011 (Apr 9, 2012)

zenophryk said:


> So I'm wondering, once the top black piece is seperated from the bottom green piece, it looks and sounds like the only materials in the top black piece is the silicon wafer, the bonding wires, and the resin encapsulation. There's no Iron, or copper or anything else right?



That is correct.



zenophryk said:


> So if I were to incinerate a bunch of the black tops and crush that up there should be no magnetic material right?



Again correct, however some of them do have round piece of magnetic metal on top but this can be separated easily after incineration.



zenophryk said:


> So couldn't I just throw it in some AC solution and disolve the bonding wires? is the ash going to cause much of a problem with AC? I know it would with AR.
> -Z



By AC you mean HCl/Clorox? I would say that you will save on acid spent - I mean amount of acid used if you carefully wash them with water prior dissolution in AC. Also your AC will be nice yellow and easier to be filtered if you remove burnt powdered resin.


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## Geo (Apr 9, 2012)

the ash needs to be removed as much as possible because it is like a sponge and will soak up some of your solution. be sure to rinse any remaining ash well after dissolving the gold.


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## rotorpowa (Apr 9, 2012)

Hi Geo, First let me say well done. I have had a go at doing these and found it very hard to seperate the gold from the crushed black top. I useed a small gas torch to get them off, first tried a bigger one but ended up with a cap that was close going bang. Everyone keep in mind that these wires are so thin and to get all the gold the black top has to be crushed very fine any uncrushed bits bigger than the thickness of the wire can contain bits of gold. I used a blue bowl to seperate and found that even then some of the gold wire wanted to ride out with the crushed material. I crushed about 30 of them and must say it looked really good in the bowl. I am going to do some more today I will take some pics


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## Geo (Apr 10, 2012)

great,good going. yes it does have to be powdered very fine.the best trick to it i could figure out is to crush first and then remove the silicon chips.its easier to powder the ash after the chips are out. the chips are like glass and are very hard to crush into a powder.i used a mortar and pestle but maybe a small tumbler or ball mill would work better on large quantities.


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## rotorpowa (Apr 10, 2012)

Yeah, I was thinking the same and will be working on a small ball mill soon. I also used a mortar and pestle and spent over 1 hour crushing, then wet screened it and ran it in the blue bowl. I must give credit to your panning this stuff is super fine and I spent around 2 hours with the blue bowl and had alot to trouble tring not to take out the gold aswell as the ash. I think the surface area of the wire vs the SG of the gold was causing it to pull out some of the gold and I will have to re run to see how much I missed.


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## Geo (Apr 10, 2012)

after i crushed to powder,i put all the material in a pot and the pot in a catch pan. add a few drops of dish soap and fill with water. then i ran water into the pot until the water ran clear. i checked the catch pan and didnt find one wire.the picture of the small pile was done this way. i repeated this wash on that material twice.


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## TheVogfather (Apr 12, 2012)

this isn't a heat spreader it just looks like one. when they build the chip layers as it gets closer to the die less outer material is needed to hold the leads in place. so really its several layers that are smaller then the main part of the chip which resembles a heat spreader.


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## steyr223 (Apr 20, 2014)

Geo Buddy how are the grandkids

After you are done crushing all the top parts
Dont the gold wires get crushed to?

How come all the pics are always of the whole wire
(There not even bent) :lol: 

Till i actually see a pay streak as you call it ,i will never know

I will look.for the wires in my smaller bga packages

Excellent post by the way it adds the perfect info to patnors process 

Thanks steyr223. Rob


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## joubjonn (Apr 20, 2014)

When I do the black tops I usually get little curled wires. I don't crush the chips after incineration, just use my hands to break them up then run through a sieve then sort out the ash. I find HCl/Cl will work but it's time consuming especially if your acid/water mixture is a few inches tall and all the gold wires are under another inch of cons. AR is the way to go with these. I don't know if it's totally necessary to crush. I think lasersteve has mentioned before that as long as the chips are broken and the wire exposed the AR will get to it. I don't know how you could totally prove this to be true. It would be difficult to test.


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## Geo (Apr 20, 2014)

Hello Rob. the boys are doing great and growing like weeds, thank you for asking. I was very careful to preserve the wires for the close ups. If you take a close look at the following pictures, they are all wrinkled where the ash crushed. I bought a 4" porcelain mortar and pestle to do small batches but still use a food blender for larger batches. Some of those VGA chips have a sizable copper heat spreader incorporated into the resin body. I dont recommend processing those in a blender for obvious reasons.


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## Geo (Apr 20, 2014)

joubjonn said:


> When I do the black tops I usually get little curled wires. I don't crush the chips after incineration, just use my hands to break them up then run through a sieve then sort out the ash. I find HCl/Cl will work but it's time consuming especially if your acid/water mixture is a few inches tall and all the gold wires are under another inch of cons. AR is the way to go with these. I don't know if it's totally necessary to crush. I think lasersteve has mentioned before that as long as the chips are broken and the wire exposed the AR will get to it. I don't know how you could totally prove this to be true. It would be difficult to test.



I believe that is for the ceramic body chips and not the plastic body chips. I recommend that ALL the plastic be incinerated and crushed or milled. Any sizable piece of resin plastic can hold bonding wires trapped. The object is to convert all the carbon to carbon dioxide or as close as you can get so all the wires will be released. Any encased wires will not dissolve.


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## necromancer (Apr 20, 2014)

Geo, this is a fantastic post. Thank You So Much

i dont know how i missed this


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## joubjonn (Apr 20, 2014)

It was a really old thread 2009 maybe? He was using a paper shredder on plastic IC's but I can't remember if it was the black tops or just plastic IC's. But you're probably right. I'm sure you would get a better yield crushing it all up. And I think Steve was doing that so he didn't have to incinerate which I'm sure throws another variable into the mix. Having incinerated it probably would be better to crush everything where you could get away with just shredding and not crushing for the AR to get into the crevices and dissolve the wires.


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## eesakiwi (Aug 23, 2014)

To get those chips off, I just bend the board away from the chip.
Like I put the board over my knee directly under tge chip and bend it away from the chip.
Normally I hear the 'crack' as the solder breaks, then I turn the board by 90 deg and do it again.

Once the chips lifted at least one corner off the board, I slip a kitchen knife under the lifted edge.
The kitchen knifes with the bone handle work best, they are the same thickness right thru.

Then I straighten the board that lifts more of the chip off, then I lever the knife and the chip pops off.


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## Geo (Aug 23, 2014)

eesakiwi said:


> To get those chips off, I just bend the board away from the chip.
> Like I put the board over my knee directly under tge chip and bend it away from the chip.
> Normally I hear the 'crack' as the solder breaks, then I turn the board by 90 deg and do it again.
> 
> ...



Many people that scrap these things do the same thing. The only problem with it is it rips the gold plated traces from the green base. If you heat one until the epoxy comes loose, you will see a pattern of gold plated traces under the black epoxy. Other than that, rip them things off.


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## solar_plasma (Aug 23, 2014)

I scrape the leftover solder balls from the PCB and save them together with the green basis for a later tin/lead/silver/gold adventure.


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## johnny309 (Sep 15, 2014)

solar_plasma said:


> I scrape the leftover solder balls from the PCB and save them together with the green basis for a later tin/lead/silver/gold adventure.


Good luck....come with numbers....how it sound tin/lead alloy 70/30.....tin/copper/silver alloy....90/7/3......gold from soldered pad ...1 square millimeter...
First of all...I will go for the Sn....giving the most present element...but....in a form of hydroxides....
i'll be tempted to do this just because I don't want metals to go wasted....and only if I got in hand over 500 lbs....
P.S.: I did that ....on a small quantity.....and it was a mess....half a kilo of solder....and 15 liters of various solutions....and in the end.....after 2 days of work...the only conclusion was ...that I need to reconsider metal bonding and complex alloys .


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## solar_plasma (Sep 15, 2014)

In 20 years I might have some kg to do this experiment. Then we talk numbers. We'll see where the silver spot will be then. :lol:

...and it will be an electrolytic cell!


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