Intel 5100 manual Processor Thermal Characterization Parameter Relationships

Intel® 5100 MCH Chipset

The case-to-local ambient thermal characterization parameter (ΨCA) is used as a measure of the thermal performance of the overall thermal solution. It is defined by Equation 1 and is measured in units of °C/W.

Equation 1. Case-to-local Ambient Thermal Characterization Parameter (ΨCA)

ΨCA =	TCASE – TLA
	----------TDP---------------

The case-to-local ambient thermal characterization parameter, ΨCA, is comprised of ΨCS, the thermal interface material (TIM) thermal characterization parameter, and of ΨSA, the sink-to-local ambient thermal characterization parameter.

Equation 2. Case-to-local Ambient Thermal Characterization Parameter (ΨCA)

ΨCA = ΨCS + ΨSA

ΨCS is strongly dependent on the thermal conductivity and thickness of the TIM between the heatsink and device package.

ΨSA is a measure of the thermal characterization parameter from the bottom of the heatsink to the local ambient air. ΨSA is dependent on the heatsink material, thermal conductivity, and geometry. It is also strongly dependent on the air velocity through the fins of the heatsink. Figure 5 illustrates the combination of the different thermal characterization parameters.

Figure 5. Processor Thermal Characterization Parameter Relationships

TA

ΨSA

ΨCA

TS

TIM

ΨCS

TC

Device

Example 1. Calculating the Required Thermal Performance

The cooling performance, ΨCA, is defined using the thermal characterization parameter previously described. The process to determine the required thermal performance to cool the device includes the following.

1. Define a target component temperature TCASE and corresponding TDP.

Intel® 5100 Memory Controller Hub Chipset for Communications, Embedded, and Storage Applications

July 2008	TDG
Order Number: 318676-003US	13