LGA775 Socket Heatsink Loading
24
Thermal and Mechanical Design Guidelines
The case-to-local ambient thermal characterization parameter of the processor,
Ψ
CA
, is
comprised of
Ψ
CS
, the thermal interface material thermal characterization parameter,
and of
Ψ
SA
, the sink-to-local ambient thermal characterization parameter:
Ψ
CA
=
Ψ
CS
+
Ψ
SA
(Equation 2)
Where:
Ψ
CS
= Thermal characterization parameter of the thermal interface material
(°C/W)
Ψ
SA
= Thermal characterization parameter from heatsink-to-local ambient
(°C/W)
Ψ
CS
is strongly dependent on the thermal conductivity and thickness of the TIM
between the heatsink and IHS.
Ψ
SA
is a measure of the thermal characterization parameter from the bottom of the
heatsink to the local ambient air.
Ψ
SA
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 4 illustrates the combination of the different thermal characterization
parameters.
Figure 4. Processor Thermal Characterization Parameter Relationships
TIM
T
S
T
A
Ψ
CA
LGA775 Socket
Processor
IHS
System Board
T
C
Heatsink
TIM
T
S
T
A
Ψ
CA
LGA775 Socket
Processor
IHS
System Board
T
C
Heatsink
Summary of Contents for QX68000 Core 2 Extreme
Page 30: ...LGA775 Socket Heatsink Loading 30 Thermal and Mechanical Design Guidelines...
Page 74: ...Heatsink Clip Load Metrology 74 Thermal and Mechanical Design Guidelines...
Page 76: ...Thermal Interface Management 76 Thermal and Mechanical Design Guidelines...
Page 96: ...Case Temperature Reference Metrology 96 Thermal and Mechanical Design Guidelines...
Page 108: ...Legacy Fan Speed Control 108 Thermal and Mechanical Design Guidelines...
Page 112: ...BTX System Thermal Considerations 112 Thermal and Mechanical Design Guidelines...
