Junction temperature

About: Junction temperature is a research topic. Over the lifetime, 5058 publications have been published within this topic receiving 58643 citations.

SiC Wirebond Multichip Phase-Leg Module Packaging Design and Testing for Harsh Environment

Abstract: In order to take full advantage of SiC, a high-temperature wirebond package for multichip phase-leg power module using SiC devices was designed, developed, fabricated, and tested. The details of the material comparison and selection are described, thus culminating a feasible solution for high-temperature operation. A thermal cycling test with large temperature excursion (from -55°C to 250°C) was carried out to evaluate the thermomechanical reliability of the package. During the test, the substrate failed before other parts in 20 cycles. A sealing edge approach was proposed to improve the thermal reliability of the substrate. With the strengthening of the sealing material, the substrate, die-attachment, and wirebond assemblies exhibited satisfactoriness in the thermomechanical reliability tests. In order to evaluate the high-temperature operation ability of designed package, one prototype module was designed and fabricated. The high-temperature continuous power test shows that the package presented in this paper can perform well at 250°C junction temperature.

Chassis with separate thermal chamber for solid state memory

Abstract: A chassis for a network storage system contains a first thermal chamber that houses conventional electronic components and a second thermal chamber that houses non-volatile solid state memory such as flash memory. A cooling system keeps the electronics in first thermal chamber below their maximum junction temperature. Meanwhile, a temperature regulating system maintains the solid state memory in the second thermal chamber within a range of a preferred operating temperature selected to extend the lifetime and/or improve the reliability of the solid state memory. Thus, the chassis provides dual zone temperature control to improve performance of the network storage system.

Junction Temperature Measurement of IGBTs Using Short-Circuit Current as a Temperature-Sensitive Electrical Parameter for Converter Prototype Evaluation

Abstract: This paper proposes a method to measure the junction temperatures of insulated-gate bipolar transistors (IGBTs) during the converter operation for prototype evaluation. The IGBT short-circuit current is employed as the temperature-sensitive electrical parameter (TSEP). The calibration experiments show that the short-circuit current has an adequate temperature sensitivity of 0.35 ${\rm A}/^{\circ}\hbox{C} $ . The parameter also has good selectivity and linearity, which makes it suitable to be used as a TSEP. Test circuit and hardware design are proposed for the IGBT junction temperature measurement in various power electronics dc–dc and ac–dc converter applications. By connecting a temperature measurement unit to the converter and giving a short-circuit pulse during the converter operation, the short-circuit current is measured, and the IGBT junction temperature can be derived from the calibration curve. The proposed temperature measurement method is a valuable tool for prototype evaluation and avoids the unnecessary safety margin regarding device operating temperatures, which is significant particularly for high-temperature/high-density converter applications.

Real-Time Measurement of Temperature Sensitive Electrical Parameters in SiC Power MOSFETs

Abstract: This paper examines a number of techniques for junction temperature estimation of silicon carbide (SiC) MOSFET s devices based on the measurement of temperature sensitive electrical parameters for use in online condition monitoring. Linearity, sensitivity to temperature, and circuit design for practical implementation are discussed in detail. A demonstrator based on the measurement of the quasi-threshold voltage, the turn- on transient characteristic ( $di/ dt$ ), the on -state voltage, and the gate current peak is designed and validated. It is shown that the threshold voltage, the estimation of the gate current peak, and the on -state voltage have potentially good sensitivity to temperature variation and linearity over a wide operating range. Very low sensitivity to temperature is shown for $di/ dt$ . The proposed method can provide a valuable tool for continuous health monitoring in emerging applications of SiC devices to high-reliability applications.

SiC power semiconductors in HEVs: Influence of junction temperature on power density, chip utilization and efficiency

Abstract: With SiC, junction temperatures of power semiconductors of more than 700 _C are theoretically possible due to the low intrinsic charge carrier concentration of SiC. Hence, a lot of research on package configurations for power semiconductor operation above 175 _C is currently carried out, especially within the automotive industry due to the possible high ambient temperatures occurring in hybrid electric vehicles (HEVs). This paper shows, that a higher junction temperature though does not necessarily guarantee a higher utilization of the SiC chips with respect to the current that the device can conduct without overheating. The reason is, that for most power devices the power losses start to increase very rapidly at high junction temperatures while the power that can be dissipated always increases linearly with the junction temperature. The junction temperature, where the device current starts to decrease at, is derived for different SiC chips using measured onstate conduction and switching losses in this paper. This paper furthermore analyzes in detail, how the junction temperature on the one hand is influenced by boundary conditions and on the other hand influences itself the core parameters of a converter such as efficiency, the required chip area (i. e. cost) as well as the volumetric power density and thus forms an additional degree of freedom in the design of a power electronic converter. While calculating the optimum junction temperature and analyzing its impact on the system performance, it is demonstrated, how these results can help to find the best suited power semiconductor device for the particular application. The performance of the calculations is shown on a design applied to a drive inverter for hybrid electric vehicles with normally-off SiC JFETs. Operated close to the optimum junction temperature of the SiC JFETs, it reaches a power density of 51 kW/l for the power modules and the air-cooling system, which is shown to be doubled by increasing chip size and using an advanced power semiconductor package with a lower thermal resistance from junction to ambient than the for this case assumed 1 K/W.