Innovation Cooling's Diamond 7 TIM test results

[tastymannatees]

What really puzzles me is that I DID leave the center high spot unchanged. I took off only the edge profile. Seeing that the CPU and TRUE are both convex, I would have expected to see a spot in the middle with the film....I will use another film on this, before I do another step. That will leave me with one film left for other testing.

What do you think my next step should be? Should I lap both CPU and TRUE as flat as I can get? (hehe, I still have a shot at winning the "max contact contest" here... Right now, it looks like Bail is still in the lead...)

I do find is curious that the temp change compression is greater at the load values than idle. It does make me wonder about the diode/software linearity.

Trying to get a handle on the variables and attempting to control them has proven to be a daunting task in this exercise....

Regards,
Bob

As regards to lapping, It occurs to me that the film only shows where the two parts make contact so the void area could be .0005 or a mile. One idea is that it might be pretty close to the particle size. I will have to talk to the pressure film rep.

Paste impression may reveal void thickness

The next thought might be removing the excess material now allows for a little "Flex" under pressure. This is sheet metal, put 50 psi on it and and you might get a little ripple across the surface, variation might only be .001 -.002 but still appear as a void on the film. I missed that part about leaving the center intact so maybe the bubble relaxed is a ripple under pressure?

Another point- I have not looked it up but Intel has some tolerance spec somewhere on IHS flatness that probably would correlate with a TIM thickness requirement. You are never going to mate to parts closer together than the particle size of the compound. I could envision having a void that when filled with compound the particle size would be higher then the non compounded contact. That's a thought to chew on The contact areas become voids? Maybe we should be sandblasting the IHS Instead?

I am getting to the point I believe the issue is one of tolerances, mechanical and electrical. No matter what you manufacture it requires some kind tolerance spec, a range in which it functions. No manufacturing process is perfect it is always a compromise.

When Intel produces a batch of processors the are not all the same some are 3.2's others are 2.8's etc. and are sorted into separate bins according to performance, none are perfect. Diodes are the same, they function in a engineered range of use, some read higher some read lower and some may or may not be perfectly linear across a range but they perform the intended job. I believe that picturing them as a drop dead temp indicator might be like leaning on a reed and maybe the design intent is just to keep users from burning up their CPU?

123bob, it would be interesting to go for the better contact. You own a Temp meter? I could cut a groove for a thermocouple. It would be interesting to take a no result CPU and compare it to one that has a optimum result vs diode measurement.