MC7448VS1700LC Freescale Semiconductor, MC7448VS1700LC Datasheet - Page 51

• Manufacturer Part Number: MC7448VS1700LC
• Description: IC MPU RISC 1700MHZ 360-FCCLGA
• Manufacturer: Freescale Semiconductor

Specifications of MC7448VS1700LC

• Processor Type: MPC74xx PowerPC 32-Bit
• Speed: 1.7GHz
• Voltage: 1.3V
• Mounting Type: Surface Mount
• Package / Case: 360-FCCLGA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -

Due to the complexity and variety of system-level boundary conditions for today's microelectronic
equipment, the combined effects of the heat transfer mechanisms (radiation, convection, and conduction)
may vary widely. For these reasons, we recommend using conjugate heat transfer models for the board as
well as system-level designs.
For system thermal modeling, the MPC7448 thermal model is shown in
this device. Two of the volumes, solder ball-air and substrate, are modeled using the package outline size
of the package. The other two, die and bump-underfill, have the same size as the die. The silicon die should
be modeled 8.0 × 7.3 × 0.86 mm
volume. The bump and underfill layer is modeled as 8.0 × 7.3 × 0.07 mm
a thermal conductivity of 5.0 W/(m • K) in the z-direction. The substrate volume is 25 × 25 × 1.14 mm
and has 9.9 W/(m • K) isotropic conductivity in the xy-plane and 2.95 W/(m • K) in the direction of the
z-axis. The solder ball and air layer are modeled with the same horizontal dimensions as the substrate and
is 0.8 mm thick. For the LGA package the solder and air layer is 0.1 mm thick, but the material properties
are the same. It can also be modeled as a collapsed volume using orthotropic material properties:
0.034 W/(m • K) in the xy-plane direction and 11.2 W/(m • K) in the direction of the z-axis.
Freescale Semiconductor
Conductivity
Silicon
Bump and Underfill (8.0 × 7.3 × 0.07 mm
Solder Ball and Air (25 × 25 × 0.8 mm
k
k
k
k
k
k
k
z
x
y
z
x
y
z
Substrate (25 × 25 × 1.14 mm
Die (8.0 × 7.3 × 0.86 mm
MPC7448 RISC Microprocessor Hardware Specifications, Rev. 4
Figure 26. Recommended Thermal Model of MPC7448
Temperature-
dependent
3
Value
0.034
0.034
2.95
11.2
with the heat source applied as a uniform source at the bottom of the
5.0
9.9
9.9
3
)
3
)
3
W/(m • K)
W/(m • K)
W/(m • K)
W/(m • K)
)
3
)
Unit
y
z
Side View of Model (Not to Scale)
Top View of Model (Not to Scale)
x
Figure
3
collapsed in the z-direction with
Bump and Underfill
Solder and Air
26. Four volumes represent
Substrate
Substrate
Die
Die
System Design Information
3
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