Saturday, August 30th 2008
NVIDIA Updates Chip Package Materials, 55nm GPUs subject to Changes too
A product change notification (PCN) document by NVIDIA The Inquirer claims to have access to, indicates changes to the bump materials of several NVIDIA graphics processors (GPUs). Affected by this change are popular GPUs such as G92 and G92b (55nm). Changes include replacement of a High-Pb solder (95% Pb / 5% Sn) bump material with Eutectic Solder (63% Sn / 37% Pb). Bumps are those parts of the die that establish electrical contact with the leads/pins of the FC-BGA package. Failures of these bumps are irreparable leading to permanent damage. This follows several events that lead to NVIDIA owning up defects in certain mobile graphics and MCP parts.
Implications of this PCN are:
Implications of this PCN are:
- Current G92 and G92b are weaker and could be subject to failures similar to those products already diagnosed with failing packages and official announcements issued.
- This could just be a precautionary measure by NVIDIA since these changes according to the PCN are aimed "to increase supply and enhance package robustness" according to the PCN. In other words, better safe than sorry.
- Sourcing bump-processing services from a single provider is more economical than several providers doing it, as was the case with the recent mobile GPU failure fiasco. Mobile GPUs aren't much different from regular ones per say.
27 Comments on NVIDIA Updates Chip Package Materials, 55nm GPUs subject to Changes too
FCPGA junction solder is specifically exempted in the directives.
"Yes there is an exception in RoHS for lead solder that has a high melting point. However, the official RoHS rule is that while lead solders in general are prohibited, there is an exception allowing for the use of lead solder that contains at least 90% lead. The idea being that solder with at least 90% lead melted at a higher temperature and was at least somewhat safer if disposed of improperly. Otherwise, potentially there may also have been no replacements for high lead content solders that performed as well when the first RoHS directives were drawn up in 2003. Currently (2008), however, there are lead-free solders that would work, but the lead free solders are more expensive than lead based solders (by roughly three times). Using a lead-free solder with a significantly different composition may also require a new packaging design and another extensive round of qualification, too. I am not totally sure how this would be done.
It get worse, the new solder to be used by nVidia mentioned in this Inq article states that it will only contain 63% lead and 37% tin, making nVidia based cards with this solder not saleable to consumers in the EU according to RoHS directives. The replacement 63Pb/37Sn solder has a somewhat better tensile strength and a lower coefficient of thermal expansion than the older 95Pb/5Sn solder, which may be why nVidia chose this route to fix the problem. Whether nV will be selling very many products in the EU with this fix and whether this will correct the problems, is another issue."
Whether or not it's correct or not, I am not sure, but it seems fairly logical...
Anyone can download the RoHS directives & see there's no such silly minimum lead percentage as the random user at /. claims.
RoHS means NO LEAD.
Thanks for the linkage. ;)
Be optimistic, my G92 survived the Indian summer of 45 C room-temp (when the AC failed for a week). It's full of heart.
The new stuff which has less Pb and more Sn:
- melts at a lower temp
- is more brittle
- has comparably worse thermal chars
Why did they switch to this?
Which is why the laptop ones are vulnerable b/c no one cools them for shit.
Nvidia's is changing it to prevent this from happening (stronger solder).
That's what I gather from all of this.
This cycle of heating and cooling, with a huge temperature difference within a reasonably short time span is what has caused the solder to crack which in turn has caused the GPU cores to lose connection with the chip packaging. We're not talking the whole GPU losing connection with the graphics card PCB or motherboard PCB here, but rather the tiny little thing ontop of the chip packaging and that's where the problem is.
The same problem could occur on a desktop card, but as desktop cards have a bigger cooler and generally doesn't heat up and cool down as quickly, nor as often as a notebook GPU, it's highly unlikely that anyone will encounter their graphics card failing because of this problem. Yes, it could happen if you turn on and off your system and run some intense 3D application and you repeat this every 10-15min, but I don't know anyone that use their PC in this way.
Nvidia still mucked up and there are potentially a lot of notebooks that could fail because of this, but the question is how many and how soon...