IntelR 80960 RN I/O Processor Datasheet

Intel ® 80960RN I/O Processor
3.2.1.3 Thermal Resistance
The thermal resistance value for the case-to-ambient, θ CA , is used as a measure of the cooling
solution’s thermal performance.
3.2.2 Thermal Analysis
Table 12 lists the case-to-ambient thermal resistances of the 80960RN for different air flow rates
with and without a heat sink.
To calculate T A , the maximum ambient temperature to conform to a particular case temperature:
T A =T C -P(θ CA )
Compute P by multiplying I CC and V CC .Valuesforθ JC and θ CA are given in Table 12.
Junction temperature (T J ) is commonly used in reliability calculations. T J can be calculated from
θ JC (thermal resistance from junction to case) using the following equation:
T J =T C +P(θ JC )
Similarly, when T A is known, the corresponding case temperature (T C ) can be calculated as
follows:
T C =T A +P(θ CA )
The θ JA (Junction to Ambient) for this package is currently estimated at 13.10° C/Watt with no
airflow and no heatsink. The θ JA (Junction to Ambient) for this package is currently estimated at
8.30° C/Watt with no airflow and a passive heatsink:
θ JA = θ JC + θ CA
Table 12.
540-Lead H-PBGA Package Thermal Characteristics
Thermal Resistance — °C/Watt
Airflow — ft./min (m/sec)
Parameter
0
(0)
50
(0.25)
100
(0.50)
200
(1.01)
300
(1.52)
400
(2.03)
600
(3.04)
800
(4.06)
θ JC (Junction-to-Case) 0.44 0.44 0.44 0.44 0.44 0.44 0.44 0.44
θ CA (Case-to-Ambient)
Without Heatsink
12.66 11.61 10.66 9.26 8.26 7.61 6.57 5.78
θ CA (Case-to-Ambient)
With Passive 0.25 in. 9.0 8.2 7.5 6.1 5.1 4.7 3.8 3.2
Heatsink 2,3
θ CA (Case-to-Ambient)
With Passive 0.35 in. 7.86 6.96 6.06 4.56 3.66 3.16 2.56 2.16
Heatsink 2
θ JA
θ JC
θ CA
Data Sheet 39