THERMAL DISSIPATION CHARACTERISTICS OF A TAPE AUTOMATED BONDING ELECTRONIC PACKAGE

Abstract

Thermal measurements play a very important role in the successful design and thermal management of electronic packages. Accurate measurements of temperature distribution under different conditions are necessary to characterize the thermal resistance of electronic packages from the chip junction to the cooling sink. This paper deals with the effects of power dissipation, air velocity and ambient temperature on the thermal performance of a tape automated bonding (TAB) package. In this study, the characteristics of junction temperature (TJ), junction to ambient thermal resistance (θJ-A), junction to case thermal resistance (θJ-C), and case to ambient thermal resistance (θC-A) are investigated in detail. The package was placed in a custom-designed low speed wind tunnel which allows the air velocity to be varied between 0.5 m/s and 5 m/s. Package surface temperatures were measured using infrared thermography, while chip junction temperatures were indirectly obtained using the Electrical Test Method (ETM) in accordance to Military Standard 883. The experimental results show that for the TAB package, air velocity significantly affects θC-A and θJ-A but has negligible effect on θJ-C· In contrast, θJ-C was found to be dependent on power dissipation. In addition, the ambient temperature was found to have a strong effect on the thermal performance of the TAB package. For the tested TAB package, it was noted that the inner lead temperatures are higher than that of the chip epoxy surface.