Silicon Investor (SI) -- The First Internet Community

STOCKTALK

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor. We ask that you disable ad blocking while on Silicon Investor in the best interests of our community. If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.

Technology Stocks : Advanced Micro Devices - Moderated (AMD) -- Ignore unavailable to you. Want to Upgrade?

To: Joe NYC who wrote (77890)	4/22/2002 12:13:44 AM
From: ptanner	Respond to of 275872

Joe, re: integrated heat shield "larger contact area with heatsink, helps conductivity. But isn't there some loss in conductivity from the silicon to integrated heat spreader that offests it?" Unless the integrated heat shield has a higher thermal conductivity than the heatsink base it will result in poorer thermal performance as there will be an additional thermal resistance: chip to spreader. I see the benefit as primarily mechanical (protect the chip). However, since there is mechanical protection for the CPU this should allow for greater heatsink mounting pressure which would improve the overall thermal performance by compressing (thinning) the TIM. Intel has a nice article where they explore clamping pressure vs thermal resistance for the TIM - it was why the P4 has a clamping pressure of 75 pounds versus 20 pounds for Athlons. See "Mechanical Enabling for the Pentium 4 Processor..." here: intel.com I actually tried to provide an enhanced heat spreader using a one ounce silver coin. In the end it performed no better or worse than the original heatsink. This was when it occurred to me that the effort lost ground in the addition of a relatively poor thermal interface between the silver coin and the heat sink. -PT

To: Joe NYC who wrote (77890)	4/22/2002 12:22:18 AM
From: Mani1	Read Replies (3) \| Respond to of 275872

Joe, re <<What are the advantages, and can it be quantified?>> The biggest advantage, as you mentioned, is the mechanical protection of the die, specially when assembly is done by not so expert screw driver shops. The cost is the biggest disadvantage. You need to add a dispenser, a pick and place and an oven to your assembly line. It can also carry a thermal disadvantage. The best thermal solution is if the die goes directly to a heat spreader/heat sink combo. Re <<- larger contact area with heat sink, helps conductivity. But isn't there some loss in conductivity from the silicon to integrated heat spreader that offests it?>> Yes, larger contact area is not really an advantage. Because you are effectively adding a new resister in your thermal circuit. Mani