© 2014 IJIRT | Volume 1 Issue 7 | ISSN: 2349-6002 IJIRT 101234 INTERNATIONAL JOURNAL OF INNOVATIVE RESEARCH IN TECHNOLOGY 312 THERMAL ANALYSIS OF SEMICONDUCTOR SYSTEMS Swati Sharma, Manish Kumar, Rohan Chaudhary Department of Electrical and Electronics Engineering Dronacharya College of Engineering,Gurgaon Abstract- Designing a cost competitive power electronics system requires careful consideration of the thermal domain as well as the electrical domain. Similarly, over designing the system adds unnecessary cost and weight; under designing the system may lead to overheating and even system failure. Finding an optimized solution requires a good understanding of how to predict the operating temperatures of the system’s power components and how the heat generated by those components affects neighboring devices, such as capacitors and microcontrollers. No single thermal analysis tool or technique works best in all situations. Good thermal assessments require a combination of analytical calculations using thermal specifications, empirical analysis and thermal modeling. The art of thermal analysis involves using all available tools to support each other and validate their conclusions. This paper first presents the basic principles of thermal systems and then describes some of the techniques and tools needed to complete such an analysis. Power devices and low lead count packages are the primary focus, but the concepts herein are general and can be applied to lower power components and higher lead count devices such as microcontrollers. Index Terms- Die-attach performance, Raman - Thermography, FEA I. INTRODUCTION The basic principles of thermal analysis are similar to those in the electrical domain. Understanding one domain simplifies the task of becoming proficient in the other. This is especially clear when we consider thermal conduction. The two other thermal transport mechanisms are discussed later. Each domain has a “through” and an “across” variable.The variable can be thought of as the parameter that flows from one reference point to another. Current is the variable for the electrical domain and power is the through variable in the thermal domain. The across variable can be thought of as the variable that forces the flow of current or heat. In each domain the forcing function is a difference in potential; in one domain it’s temperature and in the other it’s voltage. Both systems have a resistance that impedes the flow of the through variable. Given the duality of the two systems, it is no surprise that the fundamental equations of the domains are similar.The white paper describes about convection and radiation , thermal responses,thermal modeling and empirical measurements and thermal modeling software. FIG 1:- FUNDAMENTALS RELATIONSHIPS IN THE THERMAL AND ELECTRICAL DOMAINS 1.1 TRANSIENT THERMAL RESPONSE The duality extends to transient as well as steady state conditions. The existence of capacitance in both domains results in thermal RC responses like those we are familiar with in the electrical domain. Thermal time constant is equal to the thermal R-C product, that is: tQ = RQ CQ (Eq. 2) Thermal capacitance is a function of the temperature rise associated with a given quantity of applied energy. The equation for thermal capacitance is: CQ= q t/ΔT (Eq. 3) where: q = heat transfer per second (J/s) t = time (s)