Abstract
A new user-friendliness multimedia CAD system for thermal control of notebook computers has been successfully developed on Microsoft Windows 98 system. New multimedia technologies, such as voice helper, graphical illustrations, animated Graphics Interchange Format (GIF) and image composition, employed in the present developed CAD system provide a very friendly and interactive interface for users. Besides, this CAD system has overcome the difficulty of building arbitrary discrete heat sources on a main PCB by setting more flexible analysis environment. Also, It has built in six models to perform the thermal analysis for various notebook computers; and provided composite colorful transient- and steady-state isotherms with the real PCB image or the PCB layout. From the present study, the theoretical predictions achieve a good consistency with the existing experimental data for 75MHz and 133 MHz notebook computers. In addition, the effects of K on the temperature rises for the components of interest except CPU are insignificant; while, the CPU temperature rise significantly decreases with increasing K. Furthermore, the thermal behaviors of notebook computers with various mobile CPU types by using the present developed CAD system have been explored. As expected, the temperature rises for all the elements of interest increase with increasing CPU clock speed. A series of exponential formulas with specific heating time constants can well predict transient experimental distributions for the important elements, such as keyboard, cabinet surfaces, air inside the cabinet and heat sink/heat pipe assembly, of the notebook computer. These formulas can be considered as the known boundary conditions to solve the detailed transient temperature distributions of the components of interest on the main PCB.