tspc603r ATMEL Corporation, tspc603r Datasheet - Page 7

• Manufacturer Part Number: tspc603r
• Description: Powerpc 603e Risc Microprocessor Family Pid7t-603e
• Manufacturer: ATMEL Corporation

8. Thermal Characteristics
8.1
5410B–HIREL–09/05
CBGA 255 and CI-CGA 255 Packages
The data found in this section concerns 603R devices packaged in the 255-lead 21 mm
multi-layer ceramic (MLC) and ceramic BGA package. Data is included for use with a Thermal-
loy #2328B heat sink.
The internal thermal resistance for this package is negligible due to the exposed die design. A
thermal interface material is recommended at the package lid to heat sink interface to minimize
the thermal contact resistance.
Additionally, the CBGA package offers an excellent thermal connection to the card and power
planes. Heat generated at the chip is dissipated through the package, the heat sink (when used)
and the card. The parallel heat flow paths result in the lowest overall thermal resistance as well
as offer significantly better power dissipation capability if a heat sink is not used.
The thermal characteristics for the flip-chip CBGA and CI-CGA packages are as follows:
The junction temperature can be calculated from the junction to ambient thermal resistance, as
follow:
Junction temperature:
During operation, the die-junction temperatures (T
the value specified in
The thermal resistance of the thermal interface material (R
Assuming a T
device would be as follow:
For the Thermalloy heat sink #2328B, the heat sink-to-ambient thermal resistance (R
airflow velocity is shown in
Thermal resistance (junction-to-case) = R
θ
Thermal resistance (junction-to-ball) = R
θ
Thermal resistance (junction-to-bottom SCI) = R
θ
where:
jc
jb
js
T
= 0.095°C/Watt for the 2 packages.
= 3.7°C/Watt for the CI-CGA package.
= 3.5°C/Watt for the CBGA package.
j =
85°C + (0.095°C/Watt + 1°C/Watt + R
T
T
R
R
R
P is the power dissipated by the device
a
j =
a
jc
cs
sa
of 85°C and a consumption (P) of 3.6 Watts, the junction temperature of the
is the ambient temperature in the vicinity of the device
is the die junction to case thermal resistance of the device
is the case to heat sink thermal resistance of the interface material
is the heat sink to ambient thermal resistance
T
a
+ (R
”Recommended Operating Conditions” on page
jc
+ R
Figure
cs
+ R
8-1.
sa
) × P
jb
jc
or
or
sa
) × 3.5 Watts.
j
) should be maintained at a lower value than
js
or
cs
) is typically about 1°C/Watt.
6.
TSPC603R
sa
) versus
7