| Abstract |
This paper presents a simple experimental method for the transient thermal characterisation of semiconductor packages and demonstrates the use of the method for reliability investigations. The method is based upon the assumption that in many cases, the device temperature evolution can be accurately described by a few exponential terms, as will be shown to be the case when transient thermal response has widely separated time constants. The aim is to synthesise a dynamic thermal model, composed by discrete thermal resistances and capacitances, from the measured transient response, which can be used in circuit simulators in order to predict the dynamic thermal behaviour of the device under any working condition. This paper consists of two parts. In the first one, the proposed method is described step-by-step and it is applied to a number of commercial SmartpackÆÊ modules. In the second part, an identification procedure that allows establishing the physical correspondence between the RC cells of the thermal model and the layers that constitute the electronic package is proposed. The results provide useful information about the influence of material¡¦s properties and geometry on the step-response. Finally, this paper reports on the use of the method for package quality control and reliability investigations. |
