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In the growing frequency converter market, many manufacturers offer converter types that vary in performance and size. This is where the new IGBT technology, known for its low losses and high switching frequency, comes into play. Using the new IGBT technology in modules of 62 mm (the standard size for current modules) enables users to benefit from not having to change their mechanical design concepts.

Standard 62 mm SEMITRANS® modules based on platform technology, suitable for a wide range of applications thanks to different semiconductor technologies for IGBTs and diodes. The fact that standard size module housings are available means that users have a wider choice of suppliers. The new 1200V series of modules based on Infineon's IGBT4 technology and SEMIKRON's new robust and reliable CAL4 diodes shows how perfect the match between housing and semiconductor can be.

1. IGBTs and diodes in semiconductor switches
In power electronics, semiconductor devices IGBT and diodes are only used as switches.
An "ideal switch" must satisfy the following conditions:
The on-state voltage drop Vd = 0, has nothing to do with the current conduction current
Reverse current Ir = 0, up to the maximum allowable reverse voltage
The switching loss Psw = 0, has nothing to do with the current being switched and the DC bus voltage
The thermal resistance Rth is insignificant because there are no losses
However, in practical switching, there are substantial forward and switching losses. Thus the thermal resistance in the design is critical to the module performance. This article discusses the differences between IGBT², IGBT³ and the new IGBT4 semiconductor technology used in SEMITRANS® modules, and shows the performance improvements that the new IGBT4 technology brings in some cases.

2. Advances in chip technology
IGBT4 is basically based on the known trench gate structure of IGBT3 combined with an optimized vertical structure including n-substrate, n-field stop layer and rear emitter. Compared to third-generation IGBTs, this results in lower total losses, softer switching behavior and a smaller chip area. In addition, the maximum junction temperature Tjmax of the p/n junction increases from 150°C to 175°C. This will establish a new safety margin under static and dynamic overload conditions. The IGBT4 family features a longitudinal structure optimized for high, medium and low power applications; switching performance and losses are appropriate for a given power class. The results presented here focus on applications in the medium power range (50A-600A) using low-inductance modules with switching rates between 4-12kHz (this is equivalent to IGBT4L).
When using new generation IGBTs at higher current densities, freewheeling diodes with high current densities are also required, especially for those modules with the highest chip packing density. For this reason, the new CAL4 freewheeling diode was developed on the basis of the existing CAL (Controlled Axial Long Life) diode technology, which is characterized by soft switching behavior for any current density, durability (high di/dt) and low reverse recovery peak current and turn-off losses. In order to reduce the resulting loss, the n buffer layer is optimized, using a thinner n+ wafer, the active surface area is increased (ie small edge structure), and the longitudinal carrier lifetime is optimized. So the new, improved CAL4 diodes are excellent, besides 30% higher current density, lower forward voltage and similar switching losses to the previous generation (CAL3, Tjop = constant). To increase the maximum junction temperature of the p/n junction to 175°C, a new edge passivation is used. Benefiting from the optimization work mentioned above, CAL4 FWD is a perfect match for 4th generation IGBT applications.

The extended temperature range -175°C (Tjmax) of the new generation chip is verified in appropriate reliability tests (eg: gate stress, high temperature reverse bias (HTRB), high humidity high temperature reverse bias (THB) test.