Advanced power module packaging technology is demanded with the commercialization of silicon carbide (SiC) power devices with superior performance. This paper presents an overview of currently available packaging structures suitable for SiC power modules that can deliver good performance during operation at a high temperature, frequency, and power density while incurring low loss at a high switching speed. Four typical structures—the common single-sided cooling package structure, and three double-sided cooling package structures—were chosen for comparative thermal reliability analysis that was conducted by using a finite element simulation. One of the double-sided cooling 3D package structures yielded good thermal performance, and was highly reliable. It not only lowered the junction temperature by using a single heat source but also reduced the stress and strain of the chip and the solder layer, respectively, by nearly 30% less than the single-sided cooling structure. In addition, the fatigue life of the solder under thermal cycling was significantly longer than in the other structures.

In this study, a full-scale three-dimensional trapezoidal thermoelectric cooler model is constructed to study its cooling performance and mechanical reliability using finite element simulation. Temperature dependent material properties are considered in this work. The boundary conditions similar to those in a real experimental environment are applied. The effects of the input electrical current and geometry of the thermoelectric leg on the cooling performance and reliability of a trapezoidal thermoelectric cooler are analyzed, and a comparison is made with a rectangular thermoelectric cooler. The results indicate that increasing the leg height and the variable cross-sectional design of the leg can improve the cooling performance of the trapezoidal thermoelectric cooler. Compared to the original rectangular thermoelectric cooler, the minimum chip temperature was reduced by 0.87% under the trapezoidal thermoelectric cooler with optimized geometry. Furthermore, increasing the leg height enhances the mechanical reliability of the trapezoidal thermoelectric cooler, while the trapezoidal design of the leg reduces its mechanical reliability. The maximum von Mises stress of the leg for the trapezoidal thermoelectric cooler with optimal cooling performance increased by 40.1%. The results of this work provide useful guidance for the structural design of trapezoidal thermoelectric coolers.

The thermoelectric cooler (TEC) is a kind of cooling equipment which used to dissipate heat from the devices by Peltier effect. The cooling capacity (Q_c) and coefficient of performance (COP) are both significant performance parameters of a thermoelectric cooler. In this article, three-dimensional numerical simulations are carried out by finite element analysis based on the temperature-dependent materials properties. The experimental and geometrical parameters have important effects on the TEC performance which have been analysed, such as electrical current, geometric configuration of thermoelectric leg, Thomson effect, thermal contact resistances and electrical contact resistances. The results show when the Thomson effect is ignored, the maximum difference in the cooling capacity is 7.638 W while the maximum difference in the COP is 0.09. When contact effect is not considered, the maximum difference in the cooling capacity is 22.06 W while the maximum difference in the COP is 0.75. Furthermore, the cooling capacity and COP have also been simultaneously optimized according to the multi-objective genetic algorithm. The best optimal value is obtained making use of TOPSIS (technique for order preference by similarity to an ideal solution) method from Pareto frontier. Investigated on these optimal design parameters which were anticipated to provide real guidance in industry.

An ultra-flat heteroepitaxy α-Ga₂O₃ thin film, paved a glory future for device fabrication, was successfully obtained on a c-plane sapphire substrate through the employment of the mist chemical vapor deposition technique. Atomic force microscopy measurements revealed an root mean square (RMS) roughness value of 0.309 nm when the carrier gas flow rate was set at 1500 sccm. Furthermore, the full-width at half maximum of the rocking curve was determined to be 43.2 arcsec, indicating a high level of crystallinity in the heteroepitaxy film. The growth rate was calculated as 13.22 nm min⁻¹ through the use of cross-section scanning electron microscope measurements. Additionally, the bandgap of the transparent film was determined to be 5.10 eV through transmittance spectra analysis. The high quality, wide bandgap heteroepitaxy α-Ga₂O₃ thin film described in this study represents a significant step forward in the preparation of high power and optoelectronic devices.

The lattice vibrations and optical properties of α-Ga ₂ O ₃ are investigated by polarized Raman scattering and spectroscopic ellipsometry measurements at room temperature. Three types of epitaxial α-Ga ₂ O ₃ film samples were grown on c-plane sapphire substrates by halide vapor phase epitaxy (HVPE) in three different growth modes, namely by O ₂ -control, Ga-control, and reference mode. Seven Raman active phonons and three infrared active phonons are determined experimentally for all samples. The relative intensities of E _g (2), E _g (4), and E _g (5) modes in Z(XY) Z ‾ Raman spectra varies as a function of growth mode. The growth mode has no obvious effect on the infrared active E _u (2) and E _u (4) modes, while phonon lifetime of the E _u (3) mode drastically changes. For the E _u (3) mode, the O ₂ -control sample exhibits a significantly reduced broadening factor of 7.6 cm ⁻¹ compared with that of the reference (10 cm ⁻¹ ), and the Ga-control (16.6 cm ⁻¹ ) samples. All the three types of samples show similar complex ordinary dielectric functions in the spectral range between 0.5 and 6.5 eV indicating no obvious changes within the band structure by changing the growth mode.

The electrical transport properties of indium trisulfide (In₂S₃) under high pressure were investigated using the in situ Hall-effect and temperature dependent resistivity measurements. Resistivity, Hall coefficient, carrier concentration, and mobility were obtained at pressures up to 41.6 GPa. Pressure induced metallization of In₂S₃ occurred at approximately 6.8 GPa. This was determined by measuring temperature dependent resistivity. The metallization transition was also determined from compression electrical parameters, and the decompression electrical parameters indicated that the metallization was a reversible transition. The main cause of the sharp decline in resistivity was the increase in carrier concentration at 6.8 GPa. Superconductivity was not observed at the pressures (up to 32.5 GPa) and temperatures (100–300 K) used in the experiment.