Just pondering. In the older days of CPU Mfg. they used aluminum for the interconnects. Once IBM figured out how to shield the copper from contaminating the Silicon, they went with copper. As copper is a much better conductor than aluminum, all was well. Since pure silver is a better conductor than copper, why not silver. I can find very little information on this subject matter. I understand the cost difference in copper vs silver. What I'm interested in are there techincal issues involved with using silver vs copper or is it an issue of material costs?
Copper Interconnects For CPU's-How bout Silver?
- Thread starter AdamNuhfer
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Silver is difficult to work with, mainly because it is difficult to form good interfaces between silver and other materials.
I think (I am not quite sure) there are issues with film deposition. Besides, the diffrence in conductivity between silver an copper is pretty small.
In research we use some really "odd" materials when we fabricate our samples but as far as I remember I have never seen anyone use silver for anything.
I think silver surfaces are sometimes used in biotechnology but that is the only thing I can think of.
I think (I am not quite sure) there are issues with film deposition. Besides, the diffrence in conductivity between silver an copper is pretty small.
In research we use some really "odd" materials when we fabricate our samples but as far as I remember I have never seen anyone use silver for anything.
I think silver surfaces are sometimes used in biotechnology but that is the only thing I can think of.
MobiusPizza
Platinum Member
- Apr 23, 2004
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Although silver is the best conductor, its cost limits its use to special circuits. Silver is used where a substance with high conductivity or low resistivity is needed.
Electrical Conductivity:
Silver: 63*10^6(m·O)
Copper: 59.6*10^6/(m·O)
Aluminium 37.6*10^6/(m·O)
Going from copper to silver, there's 6% improvement
from Aluminium to copper, there's 60% improvement
The benefit might just not enough to outweight the extra resources needed to devote into faesibility study and manufacturing change
Electrical Conductivity:
Silver: 63*10^6(m·O)
Copper: 59.6*10^6/(m·O)
Aluminium 37.6*10^6/(m·O)
Going from copper to silver, there's 6% improvement
from Aluminium to copper, there's 60% improvement
The benefit might just not enough to outweight the extra resources needed to devote into faesibility study and manufacturing change
Originally posted by: Mday
silver is too expensive.
Yeah, that's why they use gold in computers....
Originally posted by: Sixtyfour
Originally posted by: Mday
silver is too expensive.
Yeah, that's why they use gold in computers....
take a look at what we're talking about.
No i won't...Originally posted by: Mday
take a look at what we're talking about.
Maybe YOU should look what i quoted and answered ?
Or do you want me to highlight that part so it's easier to see ?
Remember that only VERY small amounts of a metal is actually needed to fabricate e.g. a CPU so the cost of the metal itself is rarely an issue.
The layers are probably around 100 nm thick so an order of magnitude extimate tells us that you would need someting like 0.1 g of silver to make a single CPU, and the cost of silver is only of the order of $200/kg.
The cost/kg of gold is much higer but as Sixtyfour pointed out we still use quite a lot of it in electronics, platinum, palladium, rhodium etc are even more expensive then gold but AFAIK they are still widely used.
The layers are probably around 100 nm thick so an order of magnitude extimate tells us that you would need someting like 0.1 g of silver to make a single CPU, and the cost of silver is only of the order of $200/kg.
The cost/kg of gold is much higer but as Sixtyfour pointed out we still use quite a lot of it in electronics, platinum, palladium, rhodium etc are even more expensive then gold but AFAIK they are still widely used.
- Jun 17, 2005
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f95toli: I agree, for the little bit of silver used, it shouln't matter.
AnnihilatorX: Thanks, some good info. My old school books {electrical} led me to believe silver benefit would have been much higher
Guess most of the labs are doing research in quantum computing , carbon nanotubes or photon based computers instead of electron based.
Which is all great and all for the future, but not likely to be out in the market place for average Joe consumer like me for a number of years.
So, where do they go for the interm to deal with the thermal {Power usage} issues of current chip design
AnnihilatorX: Thanks, some good info. My old school books {electrical} led me to believe silver benefit would have been much higher
Guess most of the labs are doing research in quantum computing , carbon nanotubes or photon based computers instead of electron based.
Which is all great and all for the future, but not likely to be out in the market place for average Joe consumer like me for a number of years.
So, where do they go for the interm to deal with the thermal {Power usage} issues of current chip design
Originally posted by: Sixtyfour
No i won't...Originally posted by: Mday
take a look at what we're talking about.
Maybe YOU should look what i quoted and answered ?
Or do you want me to highlight that part so it's easier to see ?
Holy crap, you need to calm down there buddy. This place is for civil discussion. Although what you said was true, it was not about the topic on hand. Silver is too expensive for the application that is being talked about. That is not to say that more expensive parts arent being used, but your comment was out of context and Mday attempted to get it back on track. Your reply was off the wall and uncalled for. I suggest you think before you post.
WHAT ?!? I said facts about materials used in computers.Originally posted by: FallenHero
Originally posted by: Sixtyfour
No i won't...Originally posted by: Mday
take a look at what we're talking about.
Maybe YOU should look what i quoted and answered ?
Or do you want me to highlight that part so it's easier to see ?
Holy crap, you need to calm down there buddy. This place is for civil discussion. Although what you said was true, it was not about the topic on hand. Silver is too expensive for the application that is being talked about. That is not to say that more expensive parts arent being used, but your comment was out of context and Mday attempted to get it back on track. Your reply was off the wall and uncalled for. I suggest you think before you post.
Also i don't need to calm down, and i dont need to think the way you do.
Wtf is with you people anyway ?
If i say facts and i stay in topic, i can correct people the way i want.
There was NOTHING WRONG in my post, NOTHING.
calm down, lol. You should stop trolling.
Originally posted by: Sixtyfour
WHAT ?!? I said facts about materials used in computers.Originally posted by: FallenHero
Originally posted by: Sixtyfour
No i won't...Originally posted by: Mday
take a look at what we're talking about.
Maybe YOU should look what i quoted and answered ?
Or do you want me to highlight that part so it's easier to see ?
Holy crap, you need to calm down there buddy. This place is for civil discussion. Although what you said was true, it was not about the topic on hand. Silver is too expensive for the application that is being talked about. That is not to say that more expensive parts arent being used, but your comment was out of context and Mday attempted to get it back on track. Your reply was off the wall and uncalled for. I suggest you think before you post.
Also i don't need to calm down, and i dont need to think the way you do.
Wtf is with you people anyway ?
If i say facts and i stay in topic, i can correct people the way i want.
There was NOTHING WRONG in my post, NOTHING.
calm down, lol. You should stop trolling.
Silver is too expensive for use in interconnects. Same as gold. However, both are used for special applications. That is what the topic at hand was about, and that is what Mday was talking about. However, you took his quote out of context to somehow prove a point that wasn't being made, and then took offense when he told you to look at the topic being discussed. He never did once deny that silver was never used, or gold was never used. Once again, you took offense way too easily. I'm done discussing it with you, so as to not derail this thread.
It's YOU who derail this thread, YOU just keep on picking but there is nothing to pick.
It's all in your head, here wasn't any offtopic, attacking etc. before YOU started to talk about those things.
I really hate to explain this, but i guess i have to since you can't understand it on your own.
Mday said that Silver is too expencive to be used, so i made a point that Gold is ALREADY USED.
And since gold is MUCH MORE EXPENSIVE, it makes high price of silver to look not so high price.
Shortbrained are you ?
It's all in your head, here wasn't any offtopic, attacking etc. before YOU started to talk about those things.
I really hate to explain this, but i guess i have to since you can't understand it on your own.
Mday said that Silver is too expencive to be used, so i made a point that Gold is ALREADY USED.
And since gold is MUCH MORE EXPENSIVE, it makes high price of silver to look not so high price.
Shortbrained are you ?
Gold is used for CPU interconnects?? CPU interconnects was the topic and the only thing currently in widespread use for that application is copper. Copper replaced aluminum in this application due to it's vastly superior conductivity. Your tone is very negative and contradictory to what this forum is all about.
Originally posted by: Vikesrock
Gold is used for CPU interconnects?? CPU interconnects was the topic and the only thing currently in widespread use for that application is copper. Copper replaced aluminum in this application due to it's vastly superior conductivity. Your tone is very negative and contradictory to what this forum is all about.
Are you people on drugs ?
Am i negative ? Damn right im am cos some fuc** keep on accusing me of lot of things !
Can you stop already ?
btw, why you are surprised if im offended after i've been blamed of who knows what ?
Just read my first post, response to it, my responce etc. You MIGHT understand that you are the rioting in here and NOT ME.
[edit]
Me being negative... Do you really expect me to pamper you after you accuse me of something that i have not done ?
Do you want gentle answers after you say: NO YOU ARE WRONG, YOU ARE JUST TROLLING HERE.
Get the picture. YOU MISUNDERSTOOD AND YOU TRY TO BLAME ME !
Some did understand that they falsely accused me but, THEY DON'T HAVE BALLS TO APOLOGIZE !.
redhatlinux
Senior member
- Oct 6, 2001
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From the dark dungeons of reality. Gold is rarely used in computers today. Gold is never pure, while silver can be. Look at the connections on your mobo for memory sticks. I have seen, 4 decades of eyes, gold connectors get badly contaminated. Silver is pure and relatively cheap. Inside the chip or cpu different processes use different materials. Whenever yo go 'off chip' a driver circuit is required. These a slower due to their capability to drive the signal, usally down some kind of bus. I have scrapped TONs of large CPU's, and in the oold days, a substantial amout of gold could be recovered. Check on the memory connectors, they used to be gold coated, but you rarely see that today.
I think it's copper that gets "contaminated", it won't happen to gold.
But gold is used in wires inside the CPU/Chip packaging, and i think it still is used since it can be made to be so narrow wire.
But that amount is much less than the amount of silver required when used to replace copper.
But gold is used in wires inside the CPU/Chip packaging, and i think it still is used since it can be made to be so narrow wire.
But that amount is much less than the amount of silver required when used to replace copper.
Originally posted by: Calin
Just look at all the gold jewelry that gets contaminated... and then look around you everywhere you can see old copper. Make a comparison.
I saw bronze weapons from 3000 years ago, and gold jewelry from 3000 years ago. Guess what was more corroded?
This post was to ??
But i can say that Gold does not corrode.
imported_Kensai
Lifer
- Nov 11, 2004
- 10,855
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Originally posted by: ELopes580
I guess everyone think they're a chemist. :roll:
Let's get an answer from someone who is a real chemist, and just taking General Chem 1 in HS/college doesnt count as you being a Chemical Engineer.
Great idea, now... To find a chemist..
hardwareuser
Member
- Jun 13, 2005
- 136
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I've always heard that gold is very resistant to corrosion.
http://www.corrosion-doctors.org/MatSelect/corrgold.htm
http://www.techplate.com/gold.htm
I'm not a chem or chem eng though.
http://www.corrosion-doctors.org/MatSelect/corrgold.htm
http://www.techplate.com/gold.htm
I'm not a chem or chem eng though.
Originally posted by: Sixtyfour
Originally posted by: Calin
Just look at all the gold jewelry that gets contaminated... and then look around you everywhere you can see old copper. Make a comparison.
I saw bronze weapons from 3000 years ago, and gold jewelry from 3000 years ago. Guess what was more corroded?
This post was to ??
But i can say that Gold does not corrode.
A response to Redhatlinux's post "I have seen, 4 decades of eyes, gold connectors get badly contaminated."
Originally posted by: Calin
Originally posted by: Sixtyfour
Originally posted by: Calin
Just look at all the gold jewelry that gets contaminated... and then look around you everywhere you can see old copper. Make a comparison.
I saw bronze weapons from 3000 years ago, and gold jewelry from 3000 years ago. Guess what was more corroded?
This post was to ??
But i can say that Gold does not corrode.
A response to Redhatlinux's post "I have seen, 4 decades of eyes, gold connectors get badly contaminated."
Gold is extremely difficult to corrode.
Judging from this, and the Mass Driver thread, I suspect redhatlinux simply talks out of his ass alot.
AdamNuhfer:
It is being considered for possible future use in both interconnects and for TFT-LCD devices but as of yet is still in the research stages. There are some papers scattered around various journals about using it but the lack of maturity means we won't see it for many years if ever. As another post mentioned there are a myriad of technologies being researched for next gen interconnects (nanotubes, nanowires, optical, etc).
From an device standpoint silver is actually superior. It won't diffuse through silicon like copper to destroy your transistors and is less likely to form voids during deposition, a major yield loss item in even leading edge copper fabs. It is however much more prone to electromigration, a problems already affecting copper processes at 130nm and 90nm nodes. Most silver etching done now is wet etch. Obviously that won't work at reduced geometries. I believe it could be feasible to plasma etch silver, at least much easier than that of copper. The only reason I mention that is I have no idea how Silver would hold up to a CMP process like copper interconnects are currently formed with.
You can deposit silver through an electroplating process (actually i've read of a electroless process also) similar to how copper is deposited. The challenge from my limited understanding lies in establishing the seed layer. You can use other materials as the seed for the silver but most of them don't play well with silicon interfaces or device operation.
True but as you scale copper down to narrow linewidths it suffers from scattering effects which can double it's actual resistance. I have no data on Silver to confirm whether or not it would suffer from the same issues.
It is being considered for possible future use in both interconnects and for TFT-LCD devices but as of yet is still in the research stages. There are some papers scattered around various journals about using it but the lack of maturity means we won't see it for many years if ever. As another post mentioned there are a myriad of technologies being researched for next gen interconnects (nanotubes, nanowires, optical, etc).
Originally posted by: f95toli
Silver is difficult to work with, mainly because it is difficult to form good interfaces between silver and other materials.
From an device standpoint silver is actually superior. It won't diffuse through silicon like copper to destroy your transistors and is less likely to form voids during deposition, a major yield loss item in even leading edge copper fabs. It is however much more prone to electromigration, a problems already affecting copper processes at 130nm and 90nm nodes. Most silver etching done now is wet etch. Obviously that won't work at reduced geometries. I believe it could be feasible to plasma etch silver, at least much easier than that of copper. The only reason I mention that is I have no idea how Silver would hold up to a CMP process like copper interconnects are currently formed with.
I think (I am not quite sure) there are issues with film deposition.
You can deposit silver through an electroplating process (actually i've read of a electroless process also) similar to how copper is deposited. The challenge from my limited understanding lies in establishing the seed layer. You can use other materials as the seed for the silver but most of them don't play well with silicon interfaces or device operation.
Besides, the diffrence in conductivity between silver an copper is pretty small.
True but as you scale copper down to narrow linewidths it suffers from scattering effects which can double it's actual resistance. I have no data on Silver to confirm whether or not it would suffer from the same issues.
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