By: Pat Ryan
Do you know who the father of heat transfer is? You probably know techniques for heat dissipation in electronic devices can include heatsinks and fans, but did you know in 1822, a French mathematical physicist developed the equation we use today to analyze conductive heat transfer in electronic devices. The equation, Fourier's law of conductivity named after J. Fourier, is central to the study of heat transfer in electronic devices and the application of thermal interface materials to improve reliability and prevent premature failures.
Could Fourier have ever predicted that semiconductor materials, such as silicon and germanium would not only be excellent electrical conductors but thermal conductors as well? Could he have known that an exception to his rule of solid materials conduct heat better that liquid would be the metals indium and bismuth. Today these materials are in the forefront of thermal designs for electronic packages including power QFN's, diodes and power devices in PCB assemblies.