Low thermal conductivity and large coefficient of thermal expansion (CTE) are the most serious disadvantages of the polymer dielectric for the interposer redistribution layer (RDL). In this paper, a high thermal conductivity and low CTE composite with polyimide (PI) matrix and diamond nanoparticles/SiC whiskers reinforcement is proposed. The preparation and characterization of the composite film are presented and the effects of the composite on the improvement of the interposer properties are investigated. With 10 wt% diamond-nanoparticles and 7 wt% SiC-whiskers, the composite film has a thermal conductivity of 1.63 W/m·K and a CTE of 16.7 ppm/°C (compared with 0.19 W/m·K and 55.6 ppm/°C of the PI). Interposers with PI RDL dielectric and the composite RDL dielectric are fabricated, respectively. The simulation result shows that the composite dielectric can significantly enhance the properties of the interposer compared with the PI dielectric. The thermal resistance of the interposer decreases from 8.04 °C/W to 1.15 °C/W. The maximum von Mises stress decreases from 72.8 MPa to 16.9 MPa and the warpage decreases from 1.13 μm to 0.15 μm. Thermal distribution tests are performed as well. The results show that the maximum temperature of the interposer decreases from 64 °C to 45.1 °C. The composite developed in this study can reduce the temperature and enhance the reliability of the chips with interposers. It has the potential to expand the application of the interposers in high thermal density integration and high reliability devices.

The elastic, mechanical, acoustic, and thermal properties of ${\mathrm{Ti}}_3$Si${\mathrm{C}}_2$, ${\mathrm{Ti}}_3$Ir${\mathrm{C}}_2$, and ${\mathrm{Ti}}_3$Au${\mathrm{C}}_2$ MAX phases were systematically investigated using first-principles calculations based on density functional theory. The computed lattice parameters and elastic, mechanical, and acoustic properties were consistent with existing experimental and theoretical findings, confirming the intrinsic mechanical stability of these MAX phases. Single-crystal elastic stiffness constants were used to derive polycrystalline elastic moduli, directional dependencies of bulk, shear, and Young’s moduli, and anisotropic factors. The results revealed a ductility sequence of ${\mathrm{Ti}}_3$Si${\mathrm{C}}_2$ < ${\mathrm{Ti}}_3$Ir${\mathrm{C}}_2$ < ${\mathrm{Ti}}_3$Au${\mathrm{C}}_2$, with ${\mathrm{Ti}}_3$Ir${\mathrm{C}}_2$ and ${\mathrm{Ti}}_3$Au${\mathrm{C}}_2$ exhibiting greater elastic anisotropy than ${\mathrm{Ti}}_3$Si${\mathrm{C}}_2$. Additionally, sound velocities, Debye temperatures, minimum thermal conductivities, melting points, and Grüneisen parameters were determined. The findings showed that ${\mathrm{Ti}}_3$Si${\mathrm{C}}_2$ outperforms ${\mathrm{Ti}}_3$Ir${\mathrm{C}}_2$ and ${\mathrm{Ti}}_3$Au${\mathrm{C}}_2$ in sound velocity, average sound velocity, Debye temperature, and minimum thermal conductivity, while ${\mathrm{Ti}}_3$Ir${\mathrm{C}}_2$ has the highest melting point and ${\mathrm{Ti}}_3$Au${\mathrm{C}}_2$ the largest Grüneisen parameter. These results provide valuable insights into the design of related materials for high-performance applications.

The microspring is a typical type of device in MEMS devices, with a wide range of application scenarios and demands, among which a popular one is the microelectroformed nickel-based planar microspring prepared by the UV-LIGA technology based on the SU-8 adhesive. It is worth noting that the yield strength of the electrodeposited nickel microstructure is low, and the toughness of the structure is not high, which is unbeneficial for the enduring and stable operation of the spring. The paper mainly presents the methods of preparing high-aspect-ratio Ni/SiCw microstructures for MEMS devices based on UV-LIGA technology, developing Ni/SiCw-based microspring samples with a thickness of 300 μm, and applying a DMA tensile tester for mechanical property tests and characterization. In addition, the paper explores the influence of heat treatment at 300 °C and 600 °C on the tensile properties and microstructure of composite coatings. The results show that the W-form microspring prepared from Ni/SiCw composites not only has a wider linear range (about 1.2 times wider) than that of pure nickel material but also has a stronger resistance capacity to plastic deformation, which is competent for MEMS device applications in environments below 300 °C. The research provides a frame of reference and guidance for improving the stable cyclic operating life of such flat springs.

This work presents a novel method of reducing on‐resistance ( R _on ) in vertical double diffusion metal oxide semiconductor (VDMOS) devices using external stress. By electrodepositing a layer of nickel (Ni) film onto the surface of drain pad, intrinsic film stress is applied on the VDMOS chip. The experiment results show that R _on was reduced by 1.7, 2.4, 4.5, 8.3 and 10.5% when the film stresses were 39.2, 49.3, 61.7, 71.6 and 80.3 MPa, respectively. Moreover, thermal stress between Ni film and VDMOS chip can further reduce R _on when the temperature increases. Compared with conventional methods for R _on reduction, this method is independent of fabrication process of VDMOS devices and capable of controlling accurately the applied stress.

The influence of Cd doping on the performance of ZnSn(OH)₆ (ZHS) as a gas sensor was systematically investigated through experimental and theoretical approaches. ZHS and Cd-doped ZHS samples were synthesized using the hydrothermal method. The microstructures of pure and Cd-doped ZHS were characterized using various techniques. The results revealed that the pure ZHS sample exhibits good crystallinity and an octahedral morphology with particle sizes ranging from 800 to 1900 nm. After Cd doping, the particle size range was decreased to 700–1500 nm. A systematic investigation of the gas-sensing properties revealed that Cd-doped ZHS exhibits superior sensing performance toward ethanol gas compared to pure ZHS. Under operating conditions of 240 °C, 100 ppm concentration, and 30% relative humidity, the response of ZHS to ethanol gas exhibited a significantly higher value compared to other tested gases. After Cd doping, the response approximately doubled. Density functional theory calculations of electronic structures revealed that the enhanced ethanol sensing mechanism of Cd-doped ZHS is attributed to the narrowed band gap caused by Cd doping, which increases electron concentration and enhances ${\mathsf{O}}^{-}$ ion adsorption on the surface.

With the development of the times, fluid simulation technology has been used in university courses. As many university courses are too theoretical and difficult to understand, in order to achieve better learning results, the author believes that visualizing abstract concepts with simulation tools can help promote the course and enable students to achieve ideal learning results. This course introduces CFD, a fluid simulation tool. Through learning this course, students can more deeply understand the principles of fluid mechanics and enhance their understanding and application ability of theoretical knowledge through simulation practice.