Microstructure characterization and thermal properties of hypereutectic Si-Al alloy for electronic packaging applications

The rapid solidified process and hot press method were performed to produce three hypereutectic 55%Si-Al, 70%Si-Al and 90%Si-Al alloys for heat dissipation materials. The results show that the atomization is an effective rapid solidified method to produce the Si-Al alloy and the size of atomized Si-Al alloy powder is less than 50 μm. The rapid solidified Si-Al alloy powder were hot pressed at 550 ℃ with the pressure of 700 MPa to obtain the relative densities of 99.4%, 99.2% and 94.4% for 55%Si-Al, 70%Si-Al and 90%Si-Al alloys, respectively. The typical physical properties, such as the thermal conductivity, coefficient of thermal expansion （CTE） and electrical conductivity of rapid solidified Si-Al alloys are acceptable as a heat dissipation material for many semiconductor devices. The 55%Si-Al alloy changes greatly （CTE） with the increase of temperature but obtains a good thermal conductivity. The CTE of 90%Si-Al alloy matches with the silicon very well but its thermal conductivity value is less than 100 W/（m.K）. Therefore, the 70%Si-Al alloy possesses the best comprehensive properties of CTE and thermal conductivity for using as the heat sink materials.

Call for Papers Journal of Electronic Science and Technology Special Section on Terahertz Technology and Applications

Terahertz waves, sitting in the gap between the middle infrared and millimeter wave regions, are known as the last vacant area of the electromagnetic spectrum that has not quite been understood and brought into applications. The Terahertz region has been the focus of research worldwide since early 1990s. Due to their unique characteristics, Terahertz technologies have a wide range of applications, such as hazard detection, high speed data communications, radio astronomy, and biomedical imaging.

Call for Papers Journal of Electronic Science and Technology Special Section on Terahertz Technology and Applications

Terahertz waves, sitting in the gap between the middle infrared and millimeter wave regions, are known as the last vacant area of the electromagnetic spectrum that has not quite been understood and brought into applications. The Terahertz region has been the focus of research worldwide since early 1990s. Due to their unique characteristics, Terahertz technologies have a wide range of applications, such as hazard detection, high speed data communications, radio astronomy, and biomedical imaging.

Call for Papers Journal of Electronic Science and Technology Special Section on Terahertz Technology and Application

Terahertz wave, sitting in the gap between middle infrared and millimeter wave, has been known as the last vacant area in spectrum that has not been quite understood and brought into applications. It has been the focus of research worldwide since early 1990s. Due to the unique characteristics of Terahertz wave, Terahertz technologies have a wide range of applications, such as hazard detection, high speed data communications, radio astronomy, biomedical imaging, etc.

Call for Papers Journal of Electronic Science and Technology Special Section on Terahertz Technology and Applications

Terahertz waves, sitting in the gap between the middle infrared and millimeter wave regions, are known as the last vacant area of the electromagnetic spectrum that has not quite been understood and brought into applications. The Terahertz region has been the focus of research worldwide since early 1990s. Due to their unique characteristics, Terahertz technologies have a wide range of applications, such as hazard detection, high speed data communications, radio astronomy, and biomedical imaging.

Characterization of a New DC-Glow Discharge Plasma Set-Up to Enhance the Electronic Circuits Performance

The (DC-GDPAU) is a DC glow discharge plasma experiment that was designed, established, and operated in the Physics Department at Ain Shams University (Egypt). The aim of this experiment is to study and improve some properties of a printed circuit board (PCB) by exposing it to the plasma. The device consists of cylindrical discharge chamber with movable parallel circular copper electrodes (cathode and anode) fixed inside it. The distance between them is 12 cm. This plasma experiment works in a low-pressure range (0.15 - 0.70 Torr) for Ar gas with a maximum DC power supply of 200 W. The Paschen curves and electrical plasma parameters (current, volt, power, resistance) characterized to the plasma have been measured and calculated at each cm between the two electrodes. Besides, the electron temperature and ion density are obtained at different radial distances using a double Langmuir probe. The electron temperature (KTe) was kept stable in range 6.58 to 10.44 eV;whereas the ion density (ni) was in range from 0.91 × 1010 cm−3 to 1.79 × 1010 cm−3. A digital optical microscope (800×) was employed to draw a comparison between the pre-and after effect of exposure to plasma on the shaping of the circuit layout. The experimental results show that the electrical conductivity increased after plasma exposure, also an improvement in the adhesion force in the Cu foil surface. A significant increase in the conductivity can be directly related to the position of the sample surfaces as well as to the time of exposure. This shows the importance of the obtained results in developing the PCBs manufacturing that uses in different microelectronics devices like those onboard of space vehicles.

Interface effect on structural and electronic properties of graphdiyne adsorbed on SiO_2 and h-BN substrates:A first-principles study

We use the first-principles calculation method to study the interface effect on the structure and electronic properties of graphdiyne adsorbed on the conventional substrates of rough SiO2 and flat h-BN. For the SiO2 substrate, we consider all possible surface terminations, including Si termination with dangling bond, Si terminations with full and partial hydrogenation, and oxygen terminations with dimerization and hydrogenation. We find that graphdiyne can maintain a flat geometry when absorbed on both h-BN and SiO2 substrates except for the Si termination with partial hydrogenation（Si-H） SiO2 substrate. A lack of surface corrugation in graphdiyne on the substrates, which may help maintain its electronic band character, is due to the weak Van der Waals interaction between graphdiyne and the substrate. Si-H SiO2 should be avoided in applications since a covalent type bonding between graphdiyne and SiO2 will totally vary the band structure of graphdiyne.Interestingly, the oxygen termination with dimerization SiO2 substrate has spontaneous p-type doping on graphdiyne via interlayer charge transfer even in the absence of extrinsic impurities in the substrate. Our result may provide a stimulus for future experiments to unveil its potential in electronic device applications.

Future Applications of GaN Electron Devices

0 Introduction Fifteen years have passed since the first AlGaN/GaN HFET was reported in 1993.The FETs have already commercialized as microwave power devices,but volume production has not yet realized.The main application field is mobile phone base stations.For such applications,GaAs power transistors and silicon LDMOS have already been used.Therefore,advantages compared with these existing devices will be required,such as high efficiency,low distortion,low noise,high reliability and,especially,low cost.However,the latter two items are normally difficult for devices using new materials.

Guest Editorial:Special Section on Applications of Power Electronics in Power Systems

Power transformers and steam turbines were the key drivers in the development of the AC power system paradigm at the dawn of the 20 th century, characterized by huge synchronous generators feeding millions of passive loads through large interconnected systems, all of them supervised and controlled from a centralized energy management system(EMS). In the same way, thyristor valves and IGBTs, introduced

Call for Papers

From energy generation to transportation, from energy distribution to storage, from semiconductor processing to communications, and from portable devices to data centers, energy consumption has grown to be a major limitation to usability and performance. Therefore, energy-efficient technologies become an active research area motivated by energy necessity and environmental concerns. With energy-efficient technologies, a number of epoch-making technical approaches can be expected. Energy efficiency technologies are affecting all forms of energy conversion and all aspects of life.

Synthesis of two-dimensional transition metal dichalcogenides for electronics and optoelectronics

Tremendous efforts have been devoted to preparing the ultrathin two-dimensional(2D)transition-metal dichalcogenides(TMDCs)and TMDCS-based heterojunctions owing to their unique properties and great potential applications in next generation electronics and optoelectronics over the past decade.However,to fulfill the demands for practical applications,the batch production of 2D TMDCs with high quality and large area at the mild condi-tions is still a challenge.This feature article reviews the state-of-the art research progresses that focus on the preparation and the applications in elec-tronics and optoelectronics of 2D TMDCs and their van der Waals hetero-junctions.First,the preparation methods including chemical and physical vapor deposition growth are comprehensively outlined.Then,recent progress on the application of fabricated 2D TMDCs based materials is revealed with particular attention to electronic(eg,field effect transistors and logic circuits)and optoelectronic(eg,photodetectors,photovoltaics,and light emitting diodes)devices.Finally,the challenges and future prospects are considered based on the current advance of 2D TMDCs and related heterojunctions.

Pave the way to the batch production of SWNT arrays for carbonbased electronic devices

Single-walled carbon nanotubes(SWNTs)have been regarded as one of the most promising candidates to supplement or even replace silicon in the post-Moore era.The requirement is to prepare the horizontally aligned SWNTs arrays(HASAs)with multiple indicators,including high density,high semiconducting purity,and wafer-scale uniformity.However,after all the fevered works being done in controlled synthesis,we still have a long way to go before realizing the application of SWNTs in highly performed electronic devices.The methods of batch production and high-throughput characterization techniques of the HASAs are the two main challenges.In this outlook,we first summarized the progresses in synthesis of HASAs with either high density or high semiconducting purity.Then the methods adopted in characterizing SWNTs and HASAs were discussed according to the different principles of characterization techniques.Afterwards,the development of carbon nanotube based electronic devices,specifically,the field effect transistors(FETs),was reviewed from three perspectives.The problems involved in electronic applications bring forward the higher request to the HASAs itself.Therefore,in the end of this outlook,we prospected the future of the synthesis and corresponding characterization of HASAs,and tried to provide our ideas about how to pave the way to the batch production of HASAs for carbon based electronic devices.