RAM chips

[Romix]

This little square chips on RAM boards got good bit of gold in it and tin.

I Cracked so many of this rectangle chips, none of them had visible gold inside.
There's solid shiny silver coloured metal, very magnetic.
What is it? Maybe pure nickel?

Same metal in this chips.

Any one know what their fingers plated with?

 

[solar_plasma]

a) http://en.wikipedia.org/wiki/Kovar
b) tin, no PMs

 

[patnor1011]

They all most then likely do have gold. You will not see it without magnifying glass and looking on correct spots.
Easy check is if you thoroughly incinerate one and then wash ash away with water in some black or dark container. Use magnifying glass and you will see it.
Check thread in my signature.

 

[Geo]

My experience with all these types of chips is to assume that they all contain gold and process accordingly.

 

[Claudie]

The bonding wires are Gold like Patnor stated, but you won't see them without magnification. Most people use incineration to process them.

 

[richard2013]

Could it be the gold wires on picture B is cover by lead due to soldering? I also did crack those and no gold wire can be seen even using a magnifying glass.

 

[Geo]

The wires are encased in the the black plastic. You can not see them unless you know exactly where and how to look. You will just have to take our word for it or you could give them all to me and I will pay the postage. 8)

 

[richard2013]

Wire bond should be connecting leadframe and silicon die,,in reballed RAM IC and BGA its very easy to see in magnifying glass the encased gold wires in the black mold compound but the picture B and C its none. Maybe we need a microscope lol. :mrgreen:

 

[solar_plasma]

You got a lot valid infos, now. If you don't understand them, it's an indication for, you have to read, read and read the forum first. Without any background knowledge to question the valid answers of people, who are more than familiar with this kind of stuff, could be felt like a kind of disrespect and ignorance and that can be frustrating. The first I come to think in such situations is, why did you ask? If you don't find those gold bond wires, the mistake is with a chance of 99% yours, in some ICs (cheap bios kindred) it could be aluminium bond wires. Start with reading about gold bonding and about IC packages, for example on wikipedia, but also on the forum you will find a lot covering this.

This is not meant harsh or mean, but I try to show you the right direction.

 

[richard2013]

No problem with that solar,,the question was simply because viewing the bond wires like I did was not possible particularly on the RAM chips described. But it is not intended to disrespect anyone. It's what I saw using a magnifiying glass. Yes it could be possibly aluminum but before asking a question I already did my home work reading bond wire types which is gold, aluminum and copper but in this ram chips its not viewable. Any way I will proceed next to burn sample of ram chips as suggested.Thanks to you.

 

[solar_plasma]

The gold wires are hard to detect without incineration. They are only around and close to the die.

 

[kurtak]

The gold wires are hard to detect without incineration. They are only around and close to the die.

correct - to the best of my knowledge "ALL" RAM chips have gold bonding wire - they are a very, VERY small wire that make's the connection (bond) between the larger wire that comes off the circuit board & into the epoxy casing & the silicon chip (die) - which is why incineration is the only real way to liberate them for processing

Kurt

 

[Romix]

I found that brown bottomed chips have much more gold in them then green chips.

 

[solar_plasma]

What do you mean by brown and green bottomed chips? I only know black memory chips.

 

[Claudie]

He may be referring to the North South bridges, verses the brown processor type packages. Just a guess though. :|

 

[Romix]

My experience with all these types of chips is to assume that they all contain gold and process accordingly.

You are right !!!
I find it.
Gold is above silicon in plastic.

 

[Romix]

What do you mean by brown and green bottomed chips? I only know black memory chips.

Little square chips underneath where the solder.
Brown or green.

 

[Barren Realms 007]

He might be talking about the fiber CPU's.

 

[shmandi]

What do you mean by brown and green bottomed chips? I only know black memory chips.

Probably refering to BGAs. If you look at photo, some have greenish and some brownish bottom

 

[Anonymous]

This thread's not about BGAs is it?