Review of research on thermal problems in TUG

Abstract

This is a prospective review of 50 years of research on thermal problems in Gdansk University of Technology, Faculty of Electronics (TUG). Main focus of this research was on metrology of thermal processes mainly using IR technology but also on development of instrumentation, analysis of thermal phenomena in semiconductor devices and applications to non-destructive testing in industrial processes as well as novel applications in medical diagnostics. Here the projects performed by the research team lead by the author of this text are presented. The main focus of research shifted in time due to general changes of economy and political situation in Poland. The early work was influenced by many constrictions – limited scientific exchange under “the iron curtain” countries as was Poland, very poor money exchange rate leading to interests on solving solutions already available in so called “the free world” but too expensive to be imported, export-import political restrictions etc. The early interests of the thermal research team came from industry and science suffering lack of availability of modern measurement instrumentation. This was especially painful in infrared domain strictly controlled by embargo restrictions. As the result several unique pyrometric type instruments were developed. An IR thermometer to measure temperature of electric motor internal rotating elements; a scanning radiation pyrometer for analysis of temperature distribution in thick film electronic devices, both using non-selective thermistor bolometer detectors. Then, a twowavelength pyrometer for measurements and control of temperature of cement mills scorch zone supplied by coal powder, operating in near IR. Following was a mirror scanning microscope with MCT cooled detector to study temperature distribution in semiconductor structures; finally series of TGS long wavelength IR detectors applied to handheld pyrometers to detect fires in coal mines. All those instruments were developed within the period 1967 – 1973 and allowed to prepare a PhD dissertation [1], devoted to analysis of detection limits in optical pyrometry. The following period 1975 – 1990 was important for advanced studies on thermal problems in semiconductor devices. Three members of the thermal problems research team completed DSc - habilitation dissertations [2, 3, 4]. As practical implementation of the research results several advanced measurement and testing sets have been developed and implemented for industrial production control in the CEMI, Centre of Semiconductors and the factory TEWA. Most advanced were: a microscope to study recombination radiation of high power diodes and thyristors, operating in near IR; testers for non-destructive determination of second breakdown of high power transistors; several automatic sets of SOA – safe operation area of different semiconductor devices; several instruments for determination of thermal resistance and