1. Situation

The constant evolution of semiconductors enables the design of systems with ever-increasing performance. Long gone are the days when the diode electron tube or the transistor reigned supreme.

In those bygone days (some applications still use tubes, such as high-voltage ballasts or audiophile amplifiers), the joules dissipated by the tube radiated through the glass into the ambient air. The only way to avoid damaging the components was to control the ambient temperature in the industrial room. Given the number of components used, the temperatures involved, and the volume of the assemblies, cooling systems were commonly used. The volume occupied by the – cooling assembly was considerable, and a failure of the ventilation system would lead to rapid degradation of the installation.

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