MPC866P datasheet(14/96 Pages) FREESCALE

14 / 96 page

MPC866/MPC859 Hardware Specifications, Rev. 2

Freescale Semiconductor

Thermal Calculation and Measurement

7.5

Experimental Determination

To determine the junction temperature of the device in the application after prototypes are available, the thermal

characterization parameter (

ΨJT) can be used to determine the junction temperature with a measurement of the

temperature at the top center of the package case using the following equation:

TJ = TT +(ΨJT x PD)

where:

JT = thermal characterization parameter

TT = thermocouple temperature on top of package

PD = power dissipation in package

The thermal characterization parameter is measured per JESD51-2 specification published by JEDEC using a 40

gauge type T thermocouple epoxied to the top center of the package case. The thermocouple should be positioned

so that the thermocouple junction rests on the package. A small amount of epoxy is placed over the thermocouple

junction and over about 1 mm of wire extending from the junction. The thermocouple wire is placed flat against the

package case to avoid measurement errors caused by cooling effects of the thermocouple wire.

7.6

References

Semiconductor Equipment and Materials International(415) 964-5111

805 East Middlefield Rd.

Mountain View, CA 94043

MIL-SPEC and EIA/JESD (JEDEC) specifications800-854-7179 or

(Available from Global Engineering Documents)303-397-7956

JEDEC Specifications http://www.jedec.org

1. C.E. Triplett and B. Joiner, “An Experimental Characterization of a 272 PBGA Within an Automotive Engine

Controller Module,” Proceedings of SemiTherm, San Diego, 1998, pp. 47-54.

2. B. Joiner and V. Adams, “Measurement and Simulation of Junction to Board Thermal Resistance and Its

Application in Thermal Modeling,” Proceedings of SemiTherm, San Diego, 1999, pp. 212-220.

MPC866P Scheda tecnica(PDF) 14 Page - Freescale Semiconductor, Inc