IEEE Transactions on Industrial Electronics Volume: 63 , Issue: 4 , Apr. 2016 , pp. 2103-2110
EV driving pattern simulation with PLECS
We propose a results of a simple motor inverter simulation with WLTC droving mode using PLECS. PLECS is the simulation platform of power electric systems.
A High-Speed and High-Accuracy SiC MOSFET Model for Simulating Practical Power Circuits
We propose a SiC MOSFET model for circuit simulation. We validated the accuracy of the proposed model by measured switching waveforms of an inductive load switching evaluation circuit. Simulation speed of the model has been validated by a three-phase inverter simulation. Excellent results have been observed for both accuracy and speed.
Ageing Monitoring of GaN Transistores using Recurrent Neural Networks
Developping a method to track GaN transistor degradation over time with recurrent neural networks. From measurements easily obtained during the normal operation of the transistor we can detect if the behavior is standard or if there is an anomaly. This method should enable live monitoring of device health.
Imaging Applications with a Single Resonnant Tunneling Diode Transceiver at 300GHz Band
We employed a single resonant tunneling diode as both a transmitter and a receiver simultaneously, and demonstrated its impact in terahertz imaging applications.It leads to simplify terahertz imaging systems.
2020 International Topical Meeting on Microwave Photonics
Influences of Device Parameters Variability on Current Sharing of Parallel-Connected SiC MOSFETs
Influence of device parameter variation on current sharing between SiC MOSFETs connected in parallel has been studied. From the simulation results, we reveal the device parameters which mainly affetct the static and dynamic current sharing behavior of the devices. We also evaluate the effect of the current sharing mismatch on energy loss for each device.
ATS2020 (Asian Test Symposium 2020)
Pore Size and Shape Dependences on Quasi-Static Tensile Characteristics of Sintered Silver Films
The presentation reveals the pore size and shape dependences on sintered silver mechanical durabilities. From stress-strain results, uniform crystal structure make sphere and small pore shape. In terms of thermal cycle reliability using sintered silver materials, uniform structure with small and sphere pore state is essential.
A method to diagnose whether the accelerometer itself is in a state of mechanical deterioration by statistically examining the output data from the accelerometer while the machine health monitoring application system is in continuous operation.
Anisotropic temperature distribution causing the incremental saturated drain-current observed in the I-V characteristic of the SiC MOSFET
The Id-Vd charactaristic in high-Id and high-Vd range of SiC-MOSFET shows incremental trend instead of saturated Id behavior. By TCAD simulation, the self-heating at measurement reproduce well this incremental trend.
Zn-doped GaN Mesa Structure As a Gate for Normally-Off AlGaN/GaN-HFET
In the evaluation of the impurity level depth in Zn-doped GaN, it was found that Zn behaves as an acceptor impurity in GaN by forming the state at 0.3 eV from the top of the valence band. Normaly-off operation was confirmed in an AlGaN/GaN HFET with a 0.1 μm mesa shape using Zn-doped GaN as the gate layer.
Current-and-Voltage Hybrid Source Gate Driver for Maximizing the Switching Capability of SiC-MOSFETs
To maximise the switching capability of SiC-MOSFET, we introduce a current and voltage hybrid source gate driver and design method.
WiPDA Asia 2020
Miniaturized 48 V‒12 V insulation-type DC/DC converter miniaturized by using GaN transistors operating at 2-MHz switching frequency
The adoption of small Qoss and small Qg GaN transistors was found to be a useful option to solve both the miniaturization and high power conversion efficiency of switching power supplies. Isolated 48 V-12 V LLC converter with a switching frequency of 2 MHz and 100 W class was fabricated, and the maximum power conversion efficiency reached 95.3%.
WiPDA Asia 2020
Research Activities to Maximize the Capability of New Power Devices
The basic characteristics of the latest generation of ROHM's SiC-MOSFETs are presented and compared with the current generation of devices in production. On the other hand, it is often assumed that better power device characteristics improve power-circuit performace, but it is not that simple. For better system-level performance, our researches of power applications and the related simulations are also presented.
WiPDA Asia 2020
The Influence of Mechanical Property on the Heat-Cycle Reliability of Sintered Silver Die Attach
This research investigates how the mechanical properties of sintered silver (s-Ag) as a die attach material influence its heat-cycle reliability. s-Ag mechanical fatigue life was 500 times under elastic stress. To investigate the correlation between fatigue mechanical test and thermal shocked test (TST), we performed TST with different temperature patterns. From TST results, higher TST gives faster degradation of s-Ag.
乗松先生 佐藤氏 (名古屋大学)
Twisted bilyaer graphene can be mocified the energy band structure by changing the rotation angle. Especially, the 1.1degree called as a magic angle can be shown the superconductivity. However, the next challenge is to obtain big scale (millimeter-scale) TBG samples. This research was shown to obtain it with using transfer graphene after annealing.
乗松先生 佐藤氏 (名古屋大学)
The method to control graphene angle on C face in SiC(000-1) is not performed, so this research is challenging to control it.
Development of practical terahertz package for resonant tunneling diode oscillators and detectors
We have devloped the world's first small general-purpose PLCC package and a high-gain antenna integrated package for terahertz devices. There are promising as a high-frequency package form that are functional and can be mass produced.
Semi-Theoretical Prediction of Turn-off Surge Voltage in a SiC MOSFET Power Module with an Embedded DC-link Decoupling Capacitor
This paper presents a semi-theoretical method for predicting the turn-off surge voltage (Vsurge) in double-pulse test (DPT) using a power module (PM) with SiC MOSFETs and an embedded DC-link decoupling capacitor. In this scheme, multiple Kirchhoff’s laws-based equations are simultaneously solved, and drain-source voltage and drain current are mathematically expressed. This calculation process is semi-theoretical, and sufficiently predicts the Vsurge observed in DPT performed under various conditions.
フォトニック結晶レーザにおける M 2 に与える反射 DBR 層の周期数の影響
Modeling of SiC UMOS chip and its application to Power Module
The modeling method developed in SiC DMOS was applied to the SiC UMOS and its versatility was verified. The model was also evaluated by comparing the switching waveforms fo a power module with SiC UMOS chip. As a result, the SiC UMOS model reproduced the measurement data with high accuracy as well as the SiC DMOS.
International Conference on Materials and Systems for Sustainability
Mechanical Property of Nano Porous Sintered Silver: Toward Reliability Estimation
The fatigue mechanical property of sintered silver plays a critical role to estimate the reliability of systems. The tensile fatigue test is performed for the sintered silver with p=5% and the bulk silver. The fatigue lifetime of the silver films is shorter than that of the bulk silver one.
Material Science Conference 2019
Dynamic On-State Resistance Measurement of GaN-HEMT by Double Pulse Test
Demonstrate the dynamic on-state resistance of GaN-HEMT and estimate inpact of loss of devices.
A gate Driver Maximizing the Switching Capability of SiC MOSFETs
This study report that high speed switching gate drive circuit for SiC MOSFETs. The provided gate drive circuit adapted subsidery capacitor in order to add gate voltage, enables increase gate current. This allows fast charge and discharge and reduced switching losses. This study confirmed that the provided gate drive circuit reduce switching loss compared to conventional one.
Dynamic Measurement Method to Extract High Voltage and High Current I-V Characteristics of SiC MOSFET with Reduced Self Heating
A novel measurement method to extract high voltage and high current I-V characteristics (HVHC I-V)of SiC MOSFET is proposed in this paper. The method could extract the HVHC I-V with extremely reduced self heating of the device. By using the method, we can measure higher voltage and current I-V characteristics than those extracted by the conventional method. It is possible for us to measure the HVHC I-V of the next generation SiC MOSFET, whose rated volatge and current is more than those of the conventional device.
Switching behavior based method to estimate the intrinsic gate resistance of a transistor by using gate plateau voltage
The internal gate resistance of SiC MOSFET effects its switching behavior larger than Si devices because it can switch at high speed with low external gate resistance. However, the convention mesurement method of internal gate resistance is not accurate. Then, we devised the new measurement method of it at switching operation by the switching waveforms.
Measurement scheme to model an SiC MOSFET for simulating its switching behaviors
The precise modeling of SiC MOSFETs are difficult by means of conventional modeling method of Si devices because of the device characteristics. Then, we invented the new modeling method for SiC MOSFETs which can reproduce its switching behavior precisely.
Thermal Warpage Behavior Analysis of Semiconductor Package of Semiconductor Packaging Structure
20th Annual International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE2019)
A High Efficiency 3-Phase 400V 15kW Power Inverter Using SiC MOSFETs and Trans-Linked Topology
A 3-phase15kW using SiC MOSFETs and trans-linked topology achieved maximum efficiency of 99.2%, and verified the benefit of combining SiC MOSFET with trans-linked technology.
A Study of Adhesion Interface about Die Bonding Structure with Conductive Silver Paste
IEEE CPMT Symposium Japan 2018
Influence of porosity on Tensile Mechanical Properties of Sintered Porous Silver Films
This paper investigates the porosity-dependent tensile mechanical properties of porous 8-10 μm thick silver films. The silver films are fabricated by pressure press, the variety of which changes the porosity (p) ranging 5% to 25%. p is determined by use of scanning electron microscopy cross-section images of the films. Stress-strain (S-S) curves are obtained by tensile tests performed for the porous and bulk silver films.Breaking strain and Ultimate tensile strengh decrease almost linearly with increase of p.
MNC 2018, 31st International Microprocesses and Nanotechnology Conference
Application of PZT thin film devices to realize IoT society
A number of IoT applications are rapidly growing. Among others, smart factory, smart infrastructure and digital medicine/health are major IoT markets. ROHM also succeeded in demonstration of healthcare monitoring utilizing non-volatile PZT devices. The essentials for IoT society and ROHM’s device applications of PZT thin film were described.
The 12th Japan-Korea Conference on Ferroelectrics (JKC-FE12)
A Small Signal AC Model Using Scalable Drain Current Equations of AlGaN/GaN MIS Enhancement HEMT
H. Aoki (帝京平成大)
A Scalable drain current model and a small-signal AC model have been developed for AlGaN/GaN MIS HEMTs with embedded source field plate. The model was found to reproduce the device characteristics well by comparing the Id-Vds, Id-Vgs, S11and H21 characteristics of the device.
A Trans-Linked 5-kW Inverter Using SiC MOSFETs to Achieve Fan-less Operation
A trans-linked 5kW interleaved inverter using SiC MOSFETs drastically reduced both tansistor loss and reactor losses, resulting in high efficiency over 99% and fanless operation.
Electro-Thermal Simulation for Predicting the Temperature of SiC Dies in the Power Module of a High Frequency Operating Power Converter
The accurate electro-thermal simulation is presented by using a new SiC die model to predict the power loss and temperature of SiC MOSFET dies in a power module. The new model incorporates a temperature dependent I-V model and body diode model which is dependent on the gate-voltage. The simulation using the model yields an accurate power loss and temperature estimate of the SiC module in a buck converter.
S-parameter Based Simulation Modeling a Power Module Independent of Measurement Data
S-parameter based simulation model for power module (PM) except for the semiconductor chips was created with electromagnetic simulation. This PM model was combined with the chip model in order to build the model of the whole structure. As a result of verifying the model by the double pulse test, the simulation waveforms which reproduce the measurement results well were obtained.
Application of PZT thin film devices to realize IoT society
ROHM has developed PZT thin film devices, such as non-volatile ferroelectric memory, highly-sensitive sensors, highly-accurate actuators, high-speed space light modulators and ultra-low-power-consumption non-volatile flip-flop devices so far. ROHM also succeeded in demonstration of healthcare monitoring utilizing non-volatile PZT devices (memory and logic). In this presentation, ROHM’s device applications of PZT thin film were described.
A Newly Developed high performance PZT thin films by using sputtering and sol-gel hybrid method for Piezo-MEMS device
We have proposed a new hybrid structure of the PZT film which we made by sol-gel method of construction on the PbTiO3 seed layer made by rf magnetron sputtering. These hybrid PZT films showed high (100)/(001) orientation and had high breakdown voltage.
Circuit Simulation of a Silicon-Carbide MOSFET Considering the Effect of the Parasitic Elements on Circuit Boards by Using S-parameters
The high speed switching of SiC MOSFET is affected by the parasitic elements of circuit board. Therefore, we analyzed the impact of stray capacitance in circuit board on the switching behavior and tried circuit simulation of the effect by use of precise model and electromagnetic simulation results of circuit board.
Resonant Tunneling Diodes for THz Applications
Present the recent advance of RTD-based terahertz devices. Based on a well-defined equivalent circuit model, circuits like mixer, detector, and oscillators have been integrated.
800 V Three-Phase LLC Series Resonant DC/DC Converter Using SiC MOSFETs
This study report that a three-phase, 5-kW LLC series resonant dc/dc converter utilizing SiC MOSFETs. The high-break down voltage of SiC MOSFETs, enables increasing the input voltage up to 800 V. Around 160kHz switchig frequency successfully reduces the volume of isolation transformers. Current-balancing transformers among each phases effectively suppress a peak current from arising in the circuit and contributed that miniaturizes the input and output capacitances. The proposed power supply weighs 1.55 kg with dimensions including a width of 18 cm, a length of 12 cm, and a height of 12.5cm. The conversion efficiency of the converter reaches 98.1% at 5-kW operation.
Thermoelectric enhancement in the two-dimensional electron gas of AlGaN/GaN heterostructures
14th European Conference on Thermoelectrics
Terahertz sensing based on photonic crystal cavity and resonant tunneling diode
Progress In Electromagnetics Research Symposium 2016 China
PIERS 2016 China
Until now, the transientcharacteristics of circuit simulations using the SiC device model have not been consistent. Since EMC must be considered when using SiC Devices, it is important to reproduce their transient characteristics. Therefore, we have developed a novel SiC devie model by measureing the Id-Vds characteristics with the high-voltage and high-current region and the on-state capacitance of the SiC MOSFET to reproduce the transient characteristics. As a result the novel SiC device model successfully reproduce the switching taransient waveform with high accuracy.
Demonstration of a robot finger using dielectric elastomer actuator
Self-Sustained Oscillation in Half Bridge Circuit of Silicon Carbide Devices with Inductive Load
The self-sustained oscillations are sometimes obserbed when SiC MOSFETs switch at high speed in the half bridge configuration. The oscillation is regard as nonlinear self-excited oscillation as a result of its device characteristics. We tried to analyze it from the aspects of device characteristics of MOSFET and trajectory of the oscillation in the I-V plane.
澤井 泰 (鶴見が発表)
Terahertz-wave integrated circuits based on photonic crystals
Progress In Electromagnetics Research Symposium 2015 Czech