Why do ceramics go for more than gold tabbed BGAs?

[mysticrey2414]

I've also been curious about this as well, every video I've seen they always mention how the ceramics are much better than bga's in recovering gold, but the price to even buy them at just seems way to outrageous for me to justify it. i have about 4 ceramics cpu's I need to process but id like to save them up until I get about a pound to see what it's all about.

Just wanted to mention that and post on here so i could get some answers as well!

I had that same problem with the ceramic CPUs, didn’t have enough to refine but I accidentally ended up becoming a cpu collector even though I know nothing about them, simply because at first they were hard to come across so I wanted to save up to refine once I got at least a lb or two. But by then, I had grown fond of my collection and now I can’t bring myself to refine them because i like them too much. I have so many now it’s ridiculous haha.

 

[malphorian1973]

I've been running CERDIPS for a week now. The major difference is with a CERDIP the acid can leach ALL of the gold out without grinding. In a plastic package this isn't possible due to the complete encapsulation of the plastic around the bond wires. I'm getting .7g from a 6.5g CERDIP in lost weight (haven't done the math yet on gold content, but i've yielded 4.15oz from ~8Kg of stock.)

Hello Brett. Hope all is well. I have a question about the CERDIPS you have been processing. Are the gold leg of the typical "silver" leg CERDIPS? Thank you for your time brother.

 

[stella polaris]

I've been running CERDIPS for a week now. The major difference is with a CERDIP the acid can leach ALL of the gold out without grinding. In a plastic package this isn't possible due to the complete encapsulation of the plastic around the bond wires. I'm getting .7g from a 6.5g CERDIP in lost weight (haven't done the math yet on gold content, but i've yielded 4.15oz from ~8Kg of stock.)

I have some kg of CERDIPS. Perhaps you want to buy them since you manage to recover almost 100 times more gold, than i manage. out of these chips?

 

[NobleMetalsRecovery]

Kurt,

Thank you for jumping in on this post and calling out the FALSE info.

This stuff is tough enough even without misleading info.

All my research only calls for gold or aluminum bond wires, nothing else.

Eproms seem to be exclusively aluminum, I believe because of higher current carrying capacity.

Steve

 

[kurtak]

Kurt,

Thank you for jumping in on this post and calling out the FALSE info.

This stuff is tough enough even without misleading info.

All my research only calls for gold or aluminum bond wires, nothing else.

Eproms seem to be exclusively aluminum, I believe because of higher current carrying capacity.

Steve

Thank you for posting to this thread - I had planned to post more here but got side tracked so your posting reminded me about this thread so IF (the BIG IF) I get time I will try posting more here (but no promise)

Kurt

 

[NobleMetalsRecovery]

Fair enough,

 

[lazersteve]

An additional note and re-emphasis of Kurt's points is that a customer recently sent me a sample of smaller (3/4" square) "BGA" ics and they did not contain any gold wires. Upon incineration I noticed the BGAs where fabricated internally using Flip-Chip technology similar to some green fiber Intel cpus. Buyer beware that not all that appear to be BGAs are what they seem.

Steve

 

[kurtak]

Upon incineration I noticed the BGAs where fabricated internally using Flip-Chip technology similar to some green fiber Intel cpus. Buyer beware that not all that appear to be BGAs are what they seem.

This is correct - not all BGAs are created equal as BGAs are made with ether wire bonding technology or with flip chip bonding technology & there is a difference - it depends on if the silicon die (actual chip) is facing up from the substrate (wire bonding) or facing down on the substrate (flip chip bonding)

https://en.wikipedia.org/wiki/Flip_chip
https://en.wikipedia.org/wiki/Wire_bonding
For the "most" part (but not always) you can tell the difference between the two types of technology because with wire bonding (& wire bonding always uses gold wires) the chip will be incased in an epoxy housing (that is uniform in shape) that is so that the bonding wires are protected from being damaged during assembly &/or handing of the complete board - whereas with flip chip technology no epoxy incasement is needed as the bonding is made direct to the leads of the substrate/board - rather then wires that are bond jumping from the top of the chip to the leads of the substrate/board

There are some flip chips that will have an epoxy covering over the chip but those will generally look like the epoxy was "poured" over the chip - rather than a distinct & uniformly molded epoxy chip with bond wires

Above I posted; - "with wire bonding (& wire bonding always uses gold wires) the chip will be incased in an epoxy housing" --- per the bold print - I posted that in bold because in the past some people have said that some epoxy chips have aluminum bond wires instead of gold bond wires & based on my experience (something like plus/minus right around 3,000 pounds of chips over several years) I have never seem epoxy chips with aluminum bond wires --- what I have seen is chips that have a "thin" aluminum heat spreader in the chip that the bottom of silicon die sits on - & when the chip is incinerated the aluminum heat spreader will melt & bleed out of the carbonized epoxy - but if you crush & pan the chip you will still find gold bond wires in the chip carbon - so it's these aluminum heat spreaders that produce little beads of aluminum when incinerating chips & not bond wires - this is speaking of epoxy chips in general including but not limited to BGAs

Now then - getting back to the question of the OP

So if you go to boardsort or any other ewaste buying website, the price they pay for ceramic CPUs is way higher than the price of gold tabbed BGAs and this baffles me,

And I agree - because at $15 per pound for gold tabbed BGAs that is priced WAY under value

It would be one thing if the $15 per pound was for mixed (any & all) BGAs) as that could certainly result in flip chips being mixed in the pound of chips which could/would certainly bring down yields

But that's not the case - gold tabbed BGAs is a specific category of BGAs & as such are VERY reliable in their yield - Boardsort even provides a picture of the specific type chip in this category -----------

https://boardsort.com/images/codes/3023.jpg
The picture showing what they are paying $15 per pound show a very specific type chip (just like specific types of CPUs) & NOT a bunch of different types of BGAs- these are the North/South bridge BGAs - & having processed something like around 300 pounds of nothing but these chips you can very reliably expect a yield of 2 grams per pounds on the whole chip (green fiber plus black epoxy - but processing only the black epoxy) or 4 grams per pound for just the black epoxy

In other words; - if you take a pound of the whole chips (green fiber & black epoxy) & you separate the black epoxy from the green fiber you will get "very" close to a half pound green fiber & a half pound of black epoxy & if you then process just the half pound of black epoxy will get very close to (plus/minus a bit) 2 grams gold (I say plus/minus because it depends how well you do with your processing) if you then process the half pound green fiber you will pick up another 0.15 - 0.25 grams gold - depending how well you do with the processing

Those chips - as advertised - should be going for $75 - $85 per pound which is 60% - 70% spot - which is fair in order to give the refiner/processer room to make his money on the deal

Kurt

 

[Goldwasser]

It would be one thing if the $15 per pound was for mixed (any & all) BGAs) as that could certainly result in flip chips being mixed in the pound of chips which could/would certainly bring down yields

But that's not the case - gold tabbed BGAs is a specific category of BGAs & as such are VERY reliable in their yield - Boardsort even provides a picture of the specific type chip in this category -----------

But that is the case. Perhaps you missed my previous reply on the subject.

You are citing the picture on our price list as your reasoning. I wish it were that simple. While in a perfect world customers would only send the "specific type of chip" based purely on the photo that we provided, our world is far from perfect, particularly when purchasing scrap from the public. I am very transparent in my pricing as demonstrated by our ceramics and gold ram which are purchased at a margin very close to the "VERY reliable" yields of which you speak when dealing with your specific BGAs. The fact is, our BGA lots are far from specific. Walk a mile in our shoes when it comes to BGA's and fingers then you will understand. My payout rates speak for themselves, I am fair, transparent with our pricing and offer some of the highest rates in the "outright purchase" market but I also operate in the reality of labor, returns and capital turnaround and some items must be what they must be. Publicly acquired BGAs and fingers are a headache on every level.

 

[Kevin.rochay]

But that is the case. Perhaps you missed my previous reply on the subject.

You are citing the picture on our price list as your reasoning. I wish it were that simple. While in a perfect world customers would only send the "specific type of chip" based purely on the photo that we provided, our world is far from perfect, particularly when purchasing scrap from the public. I am very transparent in my pricing as demonstrated by our ceramics and gold ram which are purchased at a margin very close to the "VERY reliable" yields of which you speak when dealing with your specific BGAs. The fact is, our BGA lots are far from specific. Walk a mile in our shoes when it comes to BGA's and fingers then you will understand. My payout rates speak for themselves, I am fair, transparent with our pricing and offer some of the highest rates in the "outright purchase" market but I also operate in the reality of labor, returns and capital turnaround and some items must be what they must be. Publicly acquired BGAs and fingers are a headache on every level.

I see your point. The reality of purchasing scrap is complex. I appreciate your transparency in pricing. Thank you for explaining.

 

[stella polaris]

se in the past some people have said that some epoxy chips have aluminum bond wires instead of gold bond wires & based on my experience (something like plus/minus right around 3,000 pounds of chips over several years) I have never seem epoxy chips with aluminum bond wires --- what I have seen is chips that have a "thin" aluminum heat spreader in the chip that the bottom of silicon die sits on - & when the chip is incinerated the aluminum heat spreader will melt & bleed out of the carbonized epoxy - but if you crush & pan the chip you will still find gold bond wires in the chip carbon - so it's these aluminum heat spreaders that produce little beads of aluminum when incinerating chips & not bond wires - this is speaking of epoxy chips in general including but not limited to BGAs



Kurt

Have you seen any tendencies to Bond wires trapped in the Aluminium?

 

[kurtak]

Have you seen any tendencies to Bond wires trapped in the Aluminium?

No - & yes I have checked that by dissolving the aluminum that oozes out of epoxy when incinerating the chips & have never found any "detectable" gold settling in the bottom of the beaker

Kurt

 

[Kevin.rochay]

No - & yes I have checked that by dissolving the aluminum that oozes out of epoxy when incinerating the chips & have never found any "detectable" gold settling in the bottom of the beaker

Kurt

It's interesting that no detectable gold remains after aluminum dissolution. Checking ceramic values might still be worthwhile.