Koji Nishi

J-GLOBAL         Last updated: Dec 12, 2019 at 16:15
 
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Name
Koji Nishi
E-mail
nishi.kojiv90.ashitech.ac.jp
Affiliation
Ashikaga University
Section
Faculty of Engineering Department of Innovative Engineering,Division of Electrical and Electronic Engineering

Research Interests

 
 

Research Areas

 
 

Academic & Professional Experience

 
Apr 2019
 - 
Today
Associate professor, Division of Electrical and Electronic Engineering, Ashikaga University
 
Apr 2018
 - 
Mar 2019
Lecturer, Division of Electrical and Electronic Engineering, Ashikaga University
 

Published Papers

 
Koji Nishi, Tomoyuki Hatakeyama, Shinji Nakagawa and Masaru Ishizuka
Journal of The Japan Institute of Electronics Packaging   22(4) 291-300   Jul 2019   [Refereed]
Koji Nishi
Journal of the Open CAE Society of Japan   1(1)    Jun 2018   [Refereed]
This paper discusses temperature prediction accuracy of OpenFOAM chtMultiRegionSimpleFoam solver for steady state heat conduction problem. The concept of thermal resistance and thermal spreading resistance is introduced and thermal resistance valu...
Nishi Koji
The Journal of Japan Institute for Interconnecting and Packaging Electronic Circuits   18(2) 108-112   2015   [Refereed]
Nishi Koji, Hatakeyama Tomoyuki, Nakagawa Shinji, Ishizuka Masaru
The Journal of Japan Institute for Interconnecting and Packaging Electronic Circuits   18(3) 167-178   May 2015   [Refereed]
This paper explores and discusses heat transfer paths of microprocessors in electronic equipment such as PCs (Personal Computers) and tablet devices utilizing a one-dimensional thermal network. Three-dimensional steady state heat conduction simula...
NISHI Koji
Thermal science and engineering   20(2) 27-34   Apr 2012   [Refereed]
This paper explains about fundamental formula of calculating power consumption of CMOS (Complementary Metal-Oxide-Semiconductor) devices and its voltage and temperature dependency, then introduces equation for estimating power consumption of the m...

Misc

 
Journal of the Heat Transfer Society of Japan   58(242) 36-38   Jan 2019
Koji Nishi
Journal of The Japan Institute of Electronics Packaging   22(1) 62-65   Jan 2019   [Invited]
Koji Nishi
Jornal of Japan Society for Design Engineering   53(3) 214-219   Mar 2018   [Invited]
Yoshihiro KONDO, Koji NISHI
J. HTSJ   56(235) 38-39   Apr 2017   [Invited]
Koji Nishi
日本機械学会誌   119(1171) 360‐363   Jun 2016   [Invited]
Koji Nishi
The Journal of Japan Institute for Interconnecting and Packaging Electronic Circuits   17(1) 57-59   Apr 2014   [Invited]
NISHI Koji
Journal of the Japan Society for Computational Engineering and Science   16(2) 2546-2551   Apr 2011   [Invited]

Conference Activities & Talks

 
Investigation regarding Simplified Component Configuration of Electronics Packaging
Koji Nishi
Pacific Center ISTP-30   Nov 2019   
3D semiconductor package model for precise thermal analysis
Takuya Shinoda, Ken Miyazaki, Yutaka Kumano, Ippei Yasutake, Hiroko Suzuki, Koji Nishi, Toshihiro Tsujimura, Jun Eto, Toshihiro Miyoshi, Noboru Takizawa, Qun Yuan, Koichi Hirasawa, Junichi Tachibana, Toshifumi Yoshida, Takaaki Umeda, Fumitake Endo, Keiichi Shinohara, Kimihito Hatori, Chie Sugama, Keichi Hori, Akihiko Ookasaki, Ikuo Sakurai and Masaru Tsumori
Oct 2019   
D2ELPHI Compact Thermal Model Development and Standardization for Transient Simulation
Ken Miyazaki, Yutaka Kumano, Ippei Yasutake, Hiroko Suzuki, Takuya Shinoda, Koji Nishi, Toshihiro Tsujimura, Jun Eto, Toshihiro Miyoshi, Noboru Takizawa, Qun Yuan, Koichi Hirasawa, Junichi Tachibana, Toshifumi Yoshida, Takaaki Umeda, Fumitake Endo, Keiichi Shinohara, Kimihito Hatori, Chie Sugama, Keichi Hori, Akihiko Ookasaki, Ikuo Sakurai and Masaru Tsumori
Oct 2019   
New Compact Thermal Model Development and Temperature Prediction for Microprocessor Packages
Koji Nishi
Oct 2019   
Koji Nishi
ASME InterPACK2019   Oct 2019   
In recent years, not only static thermal design but also real-time thermal control become important for power efficiency on computing systems. Three-dimensional thermal simulation is widely used to design computing system, however, it takes too lo...
Temperature Prediction and Transient Thermal Control of Electronic Equipment and Extension to Power Electronics Application
Koji Nishi
Sep 2019   
Investigation regarding Compact Thermal Model of Surface Mount Type Power Semiconductor Package
Koji Nishi
May 2019   
Research on Package Thermal Resistance of Power Semiconductor Devices
Koji Nishi
35th SEMI-THERM Symposium   Mar 2019   
Research on Package Thermal Resistance of Discrete Power Semiconductor
Koji Nishi
Mar 2019   
モデルベースデザインへの誘い - Modelicaによる物理モデリング - [Invited]
Koji Nishi
日本機械学会北陸流体工学研究会流体工学シンポジウム2016   Dec 2016   
福江 高志, 西 剛伺, 廣瀬 宏一
オープンCAEシンポジウム2016   Nov 2016   
植田 惠法, 西 剛伺, 酒井 秀久, 福江 高志
オープンCAEシンポジウム2016   Nov 2016   
Koji Nishi, Tomoyuki Hatakeyama, Shinji Nakagawa, Masaru Ishizuka
ASME InterPACKICNMM2015   Jul 2015   
The thermal network method has a long history with thermal design of electronic equipment. In particular, a one-dimensional thermal network is useful to know the temperature and heat transfer rate along each heat transfer path. It also saves compu...
Koji Nishi, Tomoyuki Hatakeyama, Shinji Nakagawa, Masaru Ishizuka
ICEP-IAAC2015   Apr 2015   
This paper proposes a new compact thermal model (CTM) for the microprocessor package based on a one-dimensional thermal network with average temperature nodes. Different from the two-resistor model and the DELPHI model, the proposed CTM doesn’t as...
Nishi Koji, Hatakeyama Tomoyuki, Nakagawa Shinji, Ishizuka Masaru
Procee[d]ings of Thermal Engineering Conference   8 Nov 2014   
This paper introduces a technique of iterative calculation to obtain thermal spreading resistance and thermal local resistance along heat transfer paths. First, the one-dimensional thermal network with average temperature nodes is explained. Secon...
1次元熱回路網を用いたスレート型タブレット筐体の伝熱経路の検証
Koji Nishi
エレクトロニクス実装学会2014ワークショップ   Oct 2014   
NISHI Koji, HATAKEYAMA Tomoyuki, NAKAGAWA Shinji, ISHIZUKA Masaru
Mechanical Engineering Congress, Japan   7 Sep 2014   
This paper explores thermal spreading resistance variation by boundary condition difference which causes heat flow difference, assuming a motherboard in slate style chassis of tablet device. Simplified motherboard model is employed and thermal spr...
Koji Nishi, Tomoyuki Hatakeyama, Shinji Nakagawa, Masaru Ishizuka
IEEE ITherm2014   May 2014   
西剛伺, 畠山友行, 中川慎二, 石塚勝
Symp Microjoining Assem Technol Electron   4 Feb 2014   
Composite components in electronic equipment are sometimes modeled as one material with effective thermal conductivity as a part of thermal simulation model. Especially, microprocessor’s package substrate has slightly complicated structure which m...
Thermal Spreading Resistance and Thermal Local Resistance Evaluations by Iterative Calculation
Koji Nishi, Tomoyuki Hatakeyama, Shinji Nakagawa, Masaru Ishizuka
ISTP-25   2014   
This paper introduces a technique of iterative calculation to obtain thermal spreading resistance and thermal local resistance along heat transfer paths. First, the one-dimensional thermal network with average temperature nodes is explained. Secon...
Koji Nishi, Tomoyuki Hatakeyama, Shinji Nakagawa, Masaru Ishizuka
IHTC15   2014   
This paper explores transient thermal behavior of the microprocessor system. Thermal control is becoming critical and transient thermal analysis is becoming highly important for system development of portable electronic equipment. Deep understandi...
Nishi K, Hatakeyama T, Nakagawa S, Ishizuka M.
2014 International Conference on Electronics Packaging, ICEP 2014   2014   
This paper explores and investigates tablet device with slate style chassis by utilizing one-dimensional thermal network expression. Thermal network is constructed from results by heat conduction simulation to well understand root causes of hot sp...
Koji Nishi, Tomoyuki Hatakeyama, Shinji Nakagawa, Masaru Ishizuka
日本伝熱シンポジウム講演論文集(CD-ROM)   2014   
JEDEC Two-resistor model is widely utilized for temperature prediction of semiconductor devices. It is very easy to use and understand, however, it is known to have temperature prediction error due to boundary condition dependency. It is important...
Nishi Koji, Hatakeyama Tomoyuki, Nakagawa Shinji, Ishizuka Masaru
Procee[d]ings of Thermal Engineering Conference   18 Oct 2013   
This paper investigates transient temperature behavior at microprocessor silicon die hot spot. The thermal local resistance is defined as a part of one-dimensional thermal network and is utilized to express microprocessor silicon die hot spot temp...
NISHI Koji, HATAKEYAMA Tomoyuki, ISHIZUKA Masaru
Mechanical Engineering Congress, Japan   8 Sep 2013   
This paper discusses modeling of transient thermal resistance behavior aiming at microprocessor silicon die temperature prediction. Temperature gradient prediction between two different-sized objects along heat conduction paths is one of key facto...
Koji Nishi, Tomoyuki Hatakeyama, Masaru Ishizuka
日本伝熱シンポジウム講演論文集   May 2013   
This paper aims to introduce simplified procedure for microprocessor silicon die temperature
estimation. This procedure calculates silicon die temperature utilizing one-dimensional thermal network
instead of utilizing heat conduction simulation. T...
Transient Heat Transfer of The Microprocessor System Investigation regarding Natural Convection with Slate Style Chassis
Koji Nishi, Tomoyuki Hatakeyama, Masaru Ishizuka
ICEP2013   Apr 2013   
This paper explores system level transient heat transfer behavior under natural convection cooling with slate style chassis assuming a tablet device design. Steady state analysis based on heat conduction simulation is conducted to see the effect o...
Koji Nishi, Tomoyuki Hatakeyama, Masaru Ishizuka
Symp Microjoining Assem Technol Electron   29 Jan 2013   
his paper introduces one-dimensional thermal network with average temperature nodes for electronic device temperature prediction. The thermal spreading resistance and the thermal local resistance are defined and implemented as a part of introduced...
Parameter Refinement of The Two-Resistor Model for CFD Simulation
Koji Nishi, Tomoyuki Hatakeyama, Shinji Nakagawa, Masaru Ishizuka
ISMNT-4   2013   
The two-resistor model is one of compact thermal models (CTM) defined for IC (Integrated Circuit) package including microprocessors as JEDEC standard(1) and can be used as a part in major CFD (Computational Fluid Dynamics) tools for electronic dev...
Modeling of Microprocessor Package Substrate with Effective Thermal Conductivity
Koji Nishi, Tomoyuki Hatakeyama, Shinji Nakagawa, Masaru Ishizuka
ISTP-24   2013   
Composite components in electronic equipment are sometimes modeled as one material with effective thermal conductivity as a part of thermal simulation model. Especially, microprocessor’s package substrate has complicated structure which may cause ...
Slate Style Electronic Device Analysis Utilizing One-Dimensional Thermal Network
Koji Nishi, Tomoyuki Hatakeyama, Shinji Nakagawa, Masaru Ishizuka
FLUCOME2013   2013   
Thermal management of electronic device is becoming more critical than ever for recent thinner stylish designs. In this paper, one-dimensional thermal network with average temperature nodes which satisfies conservation of energy is introduced and ...
Nishi K, Hatakeyama T, Ishizuka M.
ASME 2013 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems, InterPACK 2013   2013   
This paper introduces and discusses one-dimensional thermal network for microprocessor silicon die temperature prediction both under steady and transient states. Firstly, one-dimensional thermal network with average temperature nodes is constructe...
Hatakeyama Tomoyuki, Ishizuka Masaru
Procee[d]ings of Thermal Engineering Conference   16 Nov 2012   
This paper describes transient heat conduction analysis for microprocessor silicon die temperature prediction using one-dimensional thermal network. Temperature gradient prediction between two different-sized objects along heat conduction paths is...
NISHI Koji, HATAKEYAMA Tomoyuki, ISHIZUKA Masaru
Mechanical Engineering Congress, Japan   9 Sep 2012   
This paper explores applicable scope of power estimation equation for microprocessor considering voltage and temperature dependency of CMOS (Complementary Metal-Oxide-Semiconductor) devices. Firstly, the equation is introduced from fundamental equ...
Koji Nishi, Tomoyuki Hatakeyama, Masaru Ishizuka
日本伝熱シンポジウム講演論文集   May 2012   
This paper describes transient heat conduction analysis for microprocessor silicon die temperature
prediction using thermal network method. Heat conduction paths are split in a series of thin layer which is
expressed as a set of thermal resistance...
Transient Heat Conduction Simulation of The Microprocessor Investigation regarding Thermal Control with Power Limiting
Koji Nishi
ICEP-IAAC2012   Apr 2012   
Thermal control is becoming more critical than ever for portable electronic devices with thinner stylish design. For those design, power limiting is one of important features which are incorporated into the latest microprocessor. This paper aims t...
OpenCAE学会活動報告(Khronos Group、KITEに関するアップデート など)
Koji Nishi
オープンCAEワークショップ2012   2012   
Nishi Koji
Procee[d]ings of Thermal Engineering Conference   28 Oct 2011   
This paper utilizes power estimation equation for the microprocessor which was introduced in former work by the author and describes transient heat conduction simulation for the lidless micro PGA (Pin Grid Array) processor. Not only temperature an...
Transient Heat Conduction Simulation of the Lidless Micro PGA Processor
Koji Nishi
ICEP2011   Apr 2011   
This paper explains about fundamental equation of calculating power consumption of CMOS devices and its voltage and temperature dependency, then introduces equation for estimating power consumption of the lidless micro PGA (Pin Grid Array) process...
Koji Nishi
29 Oct 2010   
This paper introduces power estimation equation for the multi-core microprocessor and describes transient heat conduction simulation using the equation on simplified thermal model by sub-millisecond time step. With the latest CMOS process technolo...
Nishi Koji
Proceedings of the Society Conference of IEICE   1 Sep 2009