Abstract
Thermal analysis during the design process is an essential step towards the achievement of high reliability in modern high density hybrid and integrated circuits. Thermal analysis is also essential for modern, high density PCBs. Traditionally, a solution of the thermal problem is obtained by either the method of finite differences or the method of finite elements. Both methods, however, require a fine 3-D partition of the substrate, leading to large systems of linear equations the solution of which demands substantial computing power provided by number crunching machines and/or powerful computer work-stations.The widespread use of personal computers, however, dictates the development of new approaches to the thermal problems so that a design engineer can solve them in reasonable time with a PC. A new treatment of steady-state thermal analysis combined with a layout editor is proposed in this paper, which makes use of the analytical solution for the temperature distribution in a single-layer substrate with heat sources on the surface, and having an isothermal bottom surface. In this way the mathematical complexity of the problem is dramatically reduced allowing the thermal analysis of Multi Chip Modules (M.C.M.s) and complex hybrid circuits with the use of a PC/XT or compatible.
Highlights
Thermal analysis tools have become of fundamental importance for the design of high power hybrid and integrated circuits and for modern high density PCBs
The increasing demand for higher packing densities together with the use of modern high power integrated circuits require the complete thermal analysis of packages in order to ensure the selection of the proper substrate and the optimal location of the components
This is a realistic assumption for modern, high power hybrid circuits
Summary
After the completion of the layout and during the storage procedure the conducting paths pattern is stored separately from the pattern of the heat dissipating sources The file where the latter has been stored, contains the power density of all the cells of area ,,2, where 2 is the grid spacing used during the layout. The thermal analysis program uses as its input the power density distribution extracted during the storage procedure of the layout geometry and calculates the temperature distribution with the aid of the method which is discussed later This program has been developed in FORTRAN to take advantage of the higher processing speed offered in conjunction with the presence of a 8087 coprocessor.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
