S. Kimijima, T. Miyagi, T. Sudo and O. Shimada
A high‐density module for image processing was developed by chip‐on‐wafer technology. A silicon wafer was used as the substrate and the LSI chips were flip‐chip bonded to the…
Abstract
A high‐density module for image processing was developed by chip‐on‐wafer technology. A silicon wafer was used as the substrate and the LSI chips were flip‐chip bonded to the silicon wafer by bumps in chip‐on‐wafer technology. A primary benefit of using a silicon wafer is the little induced thermal stress which affects the bumps. The module contained a digital signal processor, SRAMs and other peripheral LSls. A total of sixteen chips were bonded on the wafer. The LSIs were connected to each other by copper/polyimide multilayer interconnections consisting of eight copper conductive layers and polyimide dielectric layers. The characteristic impedance for the signal lines was controlled to 50 ohms. The LSIs were connected to the wafer electrically and mechanically by solder bumps, which were formed on the LSI bonding pads. A 188 pin AIN ceramic package was used for the module in order to obtain high heat radiation and high reliability. The occupied area for the module was reduced to 20%, compared with the size for conventionally assembled DIPs on a PC board.
N. Takahashi, A. Muraoka, D. Miyagi, S. Fujino, K. Miyata and K. Ohashi
The paper examines the convergence characteristics of the “minimized residual method based on the MRTR (three‐term recurrence formula of CG‐type) method” for solving large linear…
Abstract
Purpose
The paper examines the convergence characteristics of the “minimized residual method based on the MRTR (three‐term recurrence formula of CG‐type) method” for solving large linear simultaneous equations.
Design/methodology/approach
The paper uses an example of magnetic field analysis of permanent magnet type of MRI taking account of the minor loop and eddy current.
Findings
It is shown that the preconditioned MRTR method can get a stable and quick convergence for such a relatively ill‐conditioned problem.
Originality/value
Illustrates that the convergence of the Incomplete Cholesky Conjugate Gradient method is one of the important issues in the practical 3D magnetic field analysis.
Details
Keywords
Norio Takahashi, Hirofumi Shinagawa, Daisuke Miyagi and Yuhito Doi
The purpose of this paper is to examine the mechanism of the increase or decrease of eddy current loss of the segmented Nd‐Fe‐B sintered magnets without insulation, and the…
Abstract
Purpose
The purpose of this paper is to examine the mechanism of the increase or decrease of eddy current loss of the segmented Nd‐Fe‐B sintered magnets without insulation, and the effects of parameters on such a phenomenon are discussed.
Design/methodology/approach
The measured contact resistance is used in the finite element analysis.
Findings
It is shown that the eddy current loss in a magnet shows the peak value when the number of segments are increased at 40 kHz, but this property is changed at low frequency (10 kHz). Its tendency is changed by the contact resistance and the permeance (surrounding iron core).
Originality/value
The reason of a curious property of eddy current loss of segmented magnets is clearly explained by examining the eddy current distribution at various contact resistances.
Details
Keywords
N. Takahashi, A. Fukum and D. Miyagi
In this paper, a new method for estimating iron loss under a distorted elliptical rotating flux is proposed.
Abstract
Purpose
In this paper, a new method for estimating iron loss under a distorted elliptical rotating flux is proposed.
Design/methodology/approach
In order to precisely analyze the iron loss of rotating machines, the iron loss under distorted rotating flux should be taken into account. However, reports of precise analysis considering measured iron loss data under rotating flux are few.
Findings
The iron loss of surface permanent magnet (SPM) motor model proposed by the investigation committee of IEE of Japan is estimated using the proposed method. The experimental examination is carried out by measuring the iron loss of the motor using a torque meter.
Originality/value
Examines an estimation method of iron loss of motors.
Details
Keywords
Norio Takahashi, Akira Akagi, Masanori Nakano, Yuhito Doi and Daisuke Miyagi
In the laminated core of transformer, motor, etc. each electrical steel sheet is usually insulated in order to reduce the eddy current loss. Raw steel sheets without insulation…
Abstract
Purpose
In the laminated core of transformer, motor, etc. each electrical steel sheet is usually insulated in order to reduce the eddy current loss. Raw steel sheets without insulation are sometimes used in a small core of electrical machines and electronic equipments, because the cost of iron core can be reduced if cheap steel sheets without insulation are used in the core. The purpose of the paper is to show how the contact resistance between sheets of laminated core affects the interlaminar eddy current and to show the criterion for judgment of the necessity of insulation.
Design/methodology/approach
The eddy current losses of core made of SPCC (cold rolled steel sheets) of different widths with and without insulation under various conditions are analyzed by using the finite element method (FEM) considering the contact resistance. The equivalent circuit for such a laminated core without insulation is shown. The experimental investigation is also carried out.
Findings
A criterion for the judgment of insulation is examined. It is shown that the increase of eddy current is affected by the ratio (this corresponds to the criterion) of the resistance of steel and the contact resistance.
Originality/value
The paper clarifies a criterion for the necessity of insulation between sheets of laminated core. It is shown that a similar tendency to the measured value of eddy current loss can be obtained by utilizing the modeling method of laminated core.
Details
Keywords
Norio Takahashi, Kousuke Shimomura, Daisuke Miyagi and Hiroyuki Kaimori
– The purpose of this paper is to propose the speed-up of the fixed-point method by updating the reluctivity at each iteration (this is called a modified fixed-point method).
Abstract
Purpose
The purpose of this paper is to propose the speed-up of the fixed-point method by updating the reluctivity at each iteration (this is called a modified fixed-point method).
Design/methodology/approach
A modified fixed-point method, which updates the derivative of reluctivity at each iteration, is proposed. It is shown that the formulation of the fixed-point method using the derivative of reluctivity is almost the same as that of the Newton-Raphson method. The convergence characteristic of the newly proposed fixed-point method is compared with those of the Newton-Raphson method.
Findings
The modified fixed-point method has an advantage that the programming is easy and it has a similar convergence property to the Newton-Raphson method for an isotropic nonlinear problem.
Originality/value
This paper presents the formulation and convergence characteristic of the modified fixed-point method are almost the same as those of the Newton-Raphson method.
Details
Keywords
Guilherme Tolentino, Guillaume Parent, Olivier Ninet, Mathieu Rossi, Jean Vianei Leite and Jonathan Blaszkowski
The horizontal rotational single-sheet tester (RSST) suffers from weaknesses such as the reduced size of test samples, measurement disturbances due to magnetic flux leakage and…
Abstract
Purpose
The horizontal rotational single-sheet tester (RSST) suffers from weaknesses such as the reduced size of test samples, measurement disturbances due to magnetic flux leakage and nonhomogeneity of field in the measurement area. Although the vertical RSST allows to overcome the first two aforementioned drawbacks, the heterogeneity of the field in the test sample remains an issue. In addition, there is still a lack of device standardization to ensure test repeatability, as already is well established with the Epstein frame. This paper aims to investigate the influence of several parameters on the field homogeneity in the test sample.
Design/methodology/approach
A fully 3D finite element model of a vertical RSST is developed and used to perform a sensibility study on several geometrical parameters.
Findings
The influence of several parameters on the field homogeneity in the test sample, such as the geometrical dimensions of the yokes, the presence or not of holes drilled inside the test sample for B-coil placement as well as the size of the H-coils and B-coils, is addressed.
Originality/value
It is expected that this study will contribute to the optimization and standardization vertical RSSTs.
Details
Keywords
Michele Forzan, Sergio Lupi and Ezio Toffano
The purpose of this paper is to present a calculation optimization method that is able to achieve the best induced power profile (and subsequent temperature distribution) in a…
Abstract
Purpose
The purpose of this paper is to present a calculation optimization method that is able to achieve the best induced power profile (and subsequent temperature distribution) in a disk or billet workpiece processed by induction heating.
Design/methodology/approach
A volume integral method, also known as the mutually coupled circuits method, is implemented in MatLab® environment to solve axial‐symmetrical induction systems. It is completed with an optimization procedure based on Nelder‐Mead simplex algorithm, with the goal of obtaining a specified distribution of the induced power in the load. In this way, it is possible to predict current amplitudes for implementing the so‐called “zone controlled induction heating” (ZCIH) process.
Findings
Some examples of calculation results are given, both for disc and billet loads. By the excitation of the inductor coils with a set of currents of appropriate amplitude and phase values, it is possible to achieve an optimized profile of induced power distributions.
Originality/value
This paper validates a method to predict currents and phases in a load‐inductor ZCIH system, confirming the possibility of obtaining specified induced power density distributions, according to the process requirements, e.g. for compensation of the load edge‐effect.
Details
Keywords
To provide a selective bibliography for researchers and graduate students who have an interest in induction processes applied to the electromagnetic processing of materials.
Abstract
Purpose
To provide a selective bibliography for researchers and graduate students who have an interest in induction processes applied to the electromagnetic processing of materials.
Design/methodology/approach
The objective is to provide references that identify seminal, early work, and references that represent the current state of the art. References are listed in categories that cover the broad range of induction modeling and application issues.
Findings
A brief overview of the key areas in induction processing of materials is provided, but greater emphasis and space is devoted to the references provided.
Research limitations/implications
The middle years of each topic area are not covered.
Practical implications
A very comprehensive coverage of material is provided to those with an interest in induction processing of materials.
Originality/value
This paper fulfils an identified information/resources need.
Details
Keywords
Surajit Bag, Arnesh Telukdarie, J.H.C. Pretorius and Shivam Gupta
The evolution of technology from the most recent industrial age to the technology era better known as Industry 4.0 resulted in greater demand for horizontal, vertical and…
Abstract
Purpose
The evolution of technology from the most recent industrial age to the technology era better known as Industry 4.0 resulted in greater demand for horizontal, vertical and end-to-end digital integration. Prior studies show that Industry 4.0 adoption majorly influences the sustainability aspects in a supply chain network. The purpose of this paper is to identify the Industry 4.0 enablers of supply chain sustainability and further attempt to propose a research framework to bridge the theoretical gaps.
Design/methodology/approach
In this research study, the authors have used a systematic literature review methodology in the field of Industry 4.0 and sustainable supply chain management. The list of papers was downloaded from Scopus (www.scopus.com) database. Through strict screening, only journal papers were selected for conducting the review of the literature.
Findings
The review brings out some interesting findings which will be helpful for the research community. There have been limited research in the area of managing supply chain network sustainability through Industry 4.0 technologies. The authors found only 10 papers out of a total of 53 papers which emphasize on smart manufacturing, smart production system, smart warehouse management system, smart logistics and sustainability. Most of the previous research studies have ignored the social aspects of supply chain sustainability. Finally, the authors identified 13 key enablers of Industry 4.0 playing an important role in driving supply chain sustainability.
Practical implications
The strategies for Industry 4.0 should be refined and detailed to develop economic and social systems that can act flexibly to sudden changes in the system. Top management must be convinced for prioritizing investment support and creating a system that can facilitate technology convergence. Managers must also act on new models of employment and frame plans to continuously improve the system. In addition, managers must focus on establishing a collaborative platform to facilitate high-tech research and developments. Finally, it is essential to develop a performance management system for monitoring all actions in the supply chain network.
Originality/value
Integrating two independent subjects is the uniqueness of the current study. Here, Industry 4.0 and supply chain sustainability have been integrated to build the research framework, and in such a process, the authors have extended the existing knowledge base.