105 Hardware Specifications

23

Preliminary/Subject to Change without Notice

Due to the complexity and the many variations 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 this reason, we recommend using conjugate heat transfer models for

the board as well as system-level designs. To expedite system-level thermal analysis, several “compact”

CBGA thermal models are available within FLOTHERM

®. These are available upon request.

The die junction-to-ambient thermal resistance is shown in Table 12. The model results are in accordance

with SEMI specification G38. This standard specifies a single component be placed on a 7.5 cm x 10 cm

single-layer printed-circuit card. Note that this single metric may not adequately describe three-dimensional

heat flow.

Table 12. Die Junction-to-Ambient Thermal Resistance

Airflow Velocity

(Meter/Second)

Airflow Velocity

(Feet/Minute)

Die Junction-to-Ambient Thermal

Resistance (SEMI G38) (

°C/W)

1

196.8

22.0

2

393.7

18.5

3

590.0

17.0

Freescale Semiconductor, Inc.

For More Information On This Product,

Go to: www.freescale.com

AR

CH

IVE

D B

Y F

RE

ES

CA

LE

SE

MI

CO

ND

UC

TO

R,

INC

.