Junction Temperature Of Diodes Research Articles

Junction and carrier temperature measurements in deep-ultraviolet light-emitting diodes using three different methods

The junction temperature of AlGaN ultraviolet light-emitting diodes emitting at 295nm is measured by using the temperature coefficients of the diode forward voltage and emission peak energy. The high-energy slope of the spectrum is explored to measure the carrier temperature. A linear relation between junction temperature and current is found. Analysis of the experimental methods reveals that the diode-forward voltage is the most accurate (±3°C). A theoretical model for the dependence of the diode forward voltage (Vf) on junction temperature (Tj) is developed that takes into account the temperature dependence of the energy gap. A thermal resistance of 87.6K∕W is obtained with the device mounted with thermal paste on a heat sink.

Junction–temperature measurement in GaN ultraviolet light-emitting diodes using diode forward voltage method

A theoretical model for the dependence of the diode forward voltage (Vf) on junction temperature (Tj) is developed. An expression for dVf∕dT is derived that takes into account all relevant contributions to the temperature dependence of the forward voltage including the intrinsic carrier concentration, the band-gap energy, and the effective density of states. Experimental results on the junction temperature of GaN ultraviolet light-emitting diodes are presented. Excellent agreement between the theoretical and experimental temperature coefficient of the forward voltage (dVf∕dT) is found. A linear relation between the junction temperature and the forward voltage is found.

Nonisothermal drift-diffusion model of avalanche diodes

A nonisothermal drift-diffusion model of avalanche diodes is described. The novel feature of the model is the inclusion of the heat conduction equation in the basic set of semiconductor equations. The influence of a nonuniform temperature distribution across the active region on the diode electrical characteristics is investigated and the usual assumption of constant diode junction temperature is evaluated. Both single-drift and double-drift diodes are simulated. The temperature distribution is calculated as a function of the dc bias current density and the amplitude of the rf driving voltage. The diode impedance is also determined and compared with results from an isothermal simulation. Numerical results are presented at J-(10–20 GHz) and W-band frequencies (75–110 GHz).

Highly Reliable High-Power 86-GHz Components and Transmitter - Receiver Modules

The reliability of semiconductor active devices is related to the junction temperature of diodes used. This paper describes the reliability design and performance of 86-GHz active components and transmitter-receiver modules for a guided millimeter-wave transmission system. The components are IMPATT oscillators, IMPATT amplifiers, varactor frequency multipliers, and Schottky-barrier diode upconverters. The maximum output powers of these active devices are calculated for a given mean time between failure (MTBF). Active components and transmitter-receiver modules for 86-GHz operation were manufactured based upon the design with considerations for reliability as well as RF performance.

New Method of Monitoring Junction Temperature

A variation of the pulse method of junction temperature measurement is presented. The new technique allows the junction temperature of diodes and transistors under stress test to be monitored by a simple procedure. An expression for correcting junction to case thermal resistances, obtained via the steady-state h rb method, for nonthermal effects is derived. Both of these ideas are illustrated by an example.