the intent of this worklog is to develop a dimensioned drawing for a heat die reflecting present industrial practice
- while there is nothing to prevent a DIYer from making and using such a device, the required resources may be substantial
- while this is a specific activity of myself/CoolingWorks, it is hoped that a general consensus might result in an open design available to anyone wishing to utilize such
(Ben jump in here - but not your WBTA please)
the general configuration of a heat die is well understood as can be seen in this old Aavid paper
http://www.aavidthermalloy.com/techn.../packaging.pdf
and there are recent papers in the last several years by both Intel and IBM describing the same configuration
-> and most notably is the 'amazing' work to the same point by 'our' Incoherent (3 cheers !)
there is nothing magical about heat dies, different designs properly executed can yield valid and comparative results as this paper by Sun illustrates
http://www.electronics-cooling.com/h...05_feb_a2.html
as most here know, a heat die is 'also' a TIM joint tester and it is well to be aware of industry practice, progress, and goals;
such can be seen here
http://www.electronics-cooling.com/h...vember_a2.html
and a TIM joint appraisal here
http://www.electronics-cooling.com/h...vember_a1.html
and here
http://www.electronics-cooling.com/h...bruary_a1.html
thermal test dies and dimensions of contact areas are reviewed here
http://www.coolingzone.com/Content/L...Sep2000_3.html
the above list is not complete, but sufficient to understand that our efforts are not in a vacuum; we do not need to reinvent the wheel (and lack the resources too, eh ?)
I have a question not addressed in the above papers:
Assuming a calorimeter type sensor placement, what is the necessity to use copper for the heat die ? (i.e. does the matl's conductivity matter so much ?)
while Ben's suggestion to use iron seems radical, why not use a more durable material ?
It seems apparent that the size/configuration of the testing heat source
must be related to the actual source size; and the wear of the copper face introduces an known and unacceptable variation in the test results (limited initial degradation progressing at an ever increasing rate).
regarding the face dimensions, I'm inclined to start with 2 sizes, 10x10mm and 12x12mm - based more on current desktop CPUs than any trend
and for the heat source 2 heater cartridges in the base
comments solicited