updated 06:55 am EST, Tue December 16, 2008
NVIDIA explains lead-bumps
Owners of the latest generation of MacBook Pros may not face the same defects in the NVIDIA GeForce 9600M chip that were prevalent in past models. The Tech Report has found that the Inquirer missed a small but important detail. The high-lead bumps used in the GPU silicon and substrate are present in the new MacBook Pros; however, NVIDIA claims there is nothing inherently wrong with the bumps themselves, and that they are used throughout the industry without problems. NVIDIA claims the problems with recent chip failures were due to a combination of errors, not specifically the lead bumps.
In a CNET chat, NVIDIA argued that the Inquirer believed the lead-bumps were the key issue at fault.
"A more robust underfill would have taken the stress off the bumps and kept that (original problem) from happening," NVIDIA VP Michael Hara says. "What we did was, we just simply went to a more robust underfill. Stopped using that (previous) underfill, kept using high-lead bumps, but we changed the underfill. And now we don't see the problem."
The new material set that NVIDIA claims has rectified the issues with past cards appears to refer to the new underfill, and the use of high-lead bumps, which the Inquirer keyed on, is allegedly a non-issue. The company needs the issues to be resolved as it recently posted a large loss due to the previous defects in its mobile and likely desktop chipsets.