Intel® Core™ 2 Duo Mobile Processors on 45-nm process for Embedded Applications
June 2008 TDG
Order Number: 320028-001 16
Thermal Solution Requirements—Core™ 2 Duo Mobile Processors
5.1.1 Calculating the Required Thermal Performance for the Intel®
Core™2 Duo processor
Overall thermal performance, ΨJA, is then defined using the thermal characterization parameter:
• Define a target component temperature TJUNCTION and corresponding TDP.
• Define a target local ambient temperature, TA.
The following provides an illustration of how to determine the appropriate performance targets.
Assume:
•TDP = 35 W and T
JUNCTION = 105 °C
• Local processor ambient temperature, TA = 40 °C.
Using Equation 1, the maximum allowable resistance, junction-to-ambient, is calculated as:
To determine the required heatsink performance, a heatsink solution provider would need to
determine ΨCA performance for the selected TIM and mechanical load configuration. If the heatsink
solution were designed to work with a TIM material performing at ΨTIM ≤ 0.50 °C/W, solving from
Equation 2, the performance of the heatsink required is:
Figure 5. Processor Thermal Characterization Parameter Relationships
Equation 3. Maximum Allowable Resistance
Equation 4. Required Performance of the Heatsink
TS
TJ
T
A
Ψ
SA
Ψ
Ψ
TIM
Device
TS
T
A
Ψ
SA
Ψ
TIM
Ψ
JA
HEATSINK

WC

TDP

TT o
AJ
JA /857.1

35

40105 =

−

=

−

=Ψ

WC

o
JSJASA /36.150.086.1 =−=Ψ−Ψ=Ψ