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Article
Publication date: 16 July 2020

Chong Hooi Lim, M.Z. Abdullah, I. Abdul Azid, C.Y. Khor, M.S. Abdul Aziz and M.H.H. Ishaik

The purpose of this study is to investigate heat transfer and deformation of flexible printed circuit board (FPCB) under thermal and flow effects by using fluid structure…

Abstract

Purpose

The purpose of this study is to investigate heat transfer and deformation of flexible printed circuit board (FPCB) under thermal and flow effects by using fluid structure interaction. This study simulate the electronic cooling process when electronic devices are generating heat during operation at FPCB under force convection.

Design/methodology/approach

The thermal and flow effects on FPCB with attached ball grid array (BGA) packages have been investigated in the simulation. Effects of Reynolds number (Re), number of BGA packages attached, power supplied to the BGA packages and size of FPCB were studied. The responses in the present study are the deflection/length of FPCB (δ/L) and Nusselt number (Nu).

Findings

It is important to consider both thermal and flow effects at the same time for understanding the characteristic of FPCB attached with BGA under operating condition. Empirical correlation equations of Re, Prandtl number (Pr), δ/L and Nu have been established, in which the highest effect is of Re, followed by Pr and δ/L. The δ/L and Nu¯ were found to be significantly affected by most of the parametric factors.

Practical implications

This study provides a better understanding of the process control in FPCB assembly.

Originality/value

This study provides fundamental guidelines and references for the thermal coupling modelling to address reliability issues in FPCB design. It also increases the understanding of FPCB and BGA joint issues to achieve high reliability in microelectronic design.

Details

Circuit World, vol. 47 no. 2
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 16 January 2007

H.W. Lee, Y.J. Teng, I.A. Azid and K.N. Seetharamu

This paper seeks to introduce an optimization method for maximizing the effectiveness of the micro compact heat exchanger (MHE) under various geometrical parameters.

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Abstract

Purpose

This paper seeks to introduce an optimization method for maximizing the effectiveness of the micro compact heat exchanger (MHE) under various geometrical parameters.

Design/methodology/approach

Optimization is realized using the neuro‐genetic methodology which combines the application of artificial neural network (ANN) together with genetic algorithms (GA). The analyses are divided into two main sections; the first being the modeling and prediction using finite element method, the second being the neuro‐genetic optimization. Initial results obtained from the finite element modeling are utilized for training in ANN. Subsequently, optimization is done using GA, once a well trained ANN is achieved.

Findings

ANN accurately predicts the effectiveness of the MHE and compares well with those obtained from the finite element simulation. Optimization shows a significant improvement in the maximum effectiveness of the MHE achievable for the given range of input parameters. Additionally, computational effort has been minimized and simulation time has been drastically reduced.

Research limitations/implications

This analysis is valid for constant fluid properties and for steady‐state conditions. Additionally, optimization is limited to the range of the trained input parameters.

Practical implications

This paper is very useful for practical design of various types of heat exchangers.

Originality/value

This paper will be useful for the design of the MHE where its performance can be analyzed for a given range of geometries with minimal effort. This methodology will also be applicable for other types of heat exchangers.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 17 no. 1
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 1 January 2005

K. Jeevan, G.A. Quadir, K.N. Seetharamu, I.A. Azid and Z.A. Zainal

To determine the optimal dimensions for a stacked micro‐channel using the genetic algorithms (GAs) under different flow constraints.

Abstract

Purpose

To determine the optimal dimensions for a stacked micro‐channel using the genetic algorithms (GAs) under different flow constraints.

Design/methodology/approach

GA is used as an optimization tool for optimizing the thermal resistance of a stacked micro‐channel under different flow constraints obtained by using the one dimensional (1D) and two dimensional (2D) finite element methods (FEM) and by thermal resistance network model as well (proposed by earlier researcher). The 2D FEM is used to study the effect of two dimensional heat conduction in the micro‐channel material. Some parametric studies are carried out to determine the resulting performance of the stacked micro‐channel. Different number of layers of the stacked micro‐channel is also investigated to study its effect on the minimum thermal resistance.

Findings

The results obtained from the 1D FEM analysis compare well with those obtained from the thermal resistance network model. However, the 2D FEM analysis results in lower thermal resistance and, therefore, the importance of considering the conduction in two dimensions in the micro‐channel is highlighted.

Research limitations/implication

The analysis is valid for constant properties fluid and for steady‐state conditions. The top‐most surfaces as well as the side surfaces of the micro‐channel are considered adiabatic.

Practical implications

The method is very useful for practical design of micro‐channel heat‐sinks.

Originality/value

FEM analyses of stacked micro‐channel can be easily implemented in the optimization procedure for obtaining the dimensions of the stacked micro‐channel heat‐sinks for minimum thermal resistance.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 15 no. 1
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 1 May 2006

K.O. Lee, K.E. Ong, K.N. Seetharamu, I.A. Azid, G.A. Quadir and T.J. Goh

Aims to present a finite element analysis based methodology for estimating the characteristic fatigue life of a solder joint interconnect under accelerated temperature…

Abstract

Purpose

Aims to present a finite element analysis based methodology for estimating the characteristic fatigue life of a solder joint interconnect under accelerated temperature cycling to predict the reliability performance of a flip chip package.

Design/methodology/approach

The method uses the ANSYSTM finite element analysis tool along with Anand's viscoplastic constitutive law. Darveaux's crack growth rate model was applied to calculate solder joint characteristic life using simulated viscoplastic strain energy density results at the package substrate and printed circuit board solder joints. Two package configurations are evaluated with the above methodology, with the first being a simplified flip chip model and the second being a detailed flip chip model. Each of these configurations is subjected to two accelerated temperature cycling tests.

Findings

Generally, the results indicate that the solder joint at the corner end of the package tends to fail first. The characteristic lives of solder joint at the package ball/board interface are 24‐46 percent higher than the characteristic lives of solder joint at the package ball/substrate interface. This means that the interface between the solder ball and substrate will fail first before the interface between the solder ball and the board.

Originality/value

Demonstrates that genetic algorithms can be used as tools to predict possible package dimensional values for given constraints on solder joint life.

Details

Microelectronics International, vol. 23 no. 2
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 1 April 2005

Kang Eu Ong, Kor Oon Lee, K.N. Seetharamu, I.A. Azid, G.A. Quadir, Z.A. Zainal and Teck Joo Goh

To find the optimal geometries of rectangular and cylindrical fins for maximum heat dissipation.

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Abstract

Purpose

To find the optimal geometries of rectangular and cylindrical fins for maximum heat dissipation.

Design/methodology/approach

The objective function for finding the optimized profiles of fins are solved by using the genetic algorithms (GAs). A range of fin shapes are investigated and the optimum solutions for various profile area are obtained.

Findings

Provide information to thermal engineers to what extent any particular extended surface or fin arrangements could improve heat dissipation from a surface to the surrounding fluid. Smaller fin volume in fin design is preferable as the heat is dissipated more effectively.

Originality/value

A new method of using GA for optimization of fins is used here. The value of this paper lies in providing data for selecting suitable fins for thermal management in electronic systems.

Research limitations/implications

Limited to cases where the correlations for heat transfer coefficients are valid.

Practical implications

A very useful finding for practising thermal engineer especially in the area of electronic packaging as the parameters for the fin design can easily be found for any chosen profile area.

Details

Microelectronics International, vol. 22 no. 1
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 1 December 2005

K. Jeevan, G.A. Quadir, K.N. Seetharamu and I.A. Azid

To determine the optimal chip/component placement for multi‐chip module (MCM) and printed circuit board (PCB) under thermal constraint.

Abstract

Purpose

To determine the optimal chip/component placement for multi‐chip module (MCM) and printed circuit board (PCB) under thermal constraint.

Design/methodology/approach

The placement of power dissipating chips/component is carried out using genetic algorithms (GA) in order to achieve uniform thermal distribution on MCM and PCB. The thermal distribution on the MCM and PCB are predicted using 2D‐finite element method (FEM) analysis. Different number of chip/component and FEM meshing size is used to investigate the placement of chips/components.

Findings

The optimal placement of chip/component using GA is compared well to other placement techniques. The coarse meshing for FEM employed here is found adequate to carry out optimal placement of components by GA.

Research limitations/implications

The analysis is valid for constant properties of MCM or PCB and steady state conditions. The chip/component size is limited to a single standard size.

Practical implications

The method is very useful for practical design of chip/component placement on MCM/PCB under thermal consideration.

Originality/value

FEM analyses of MCM and PCB can be easily implemented in the optimization procedure for obtaining the optimal chip/component placement based on thermal constraints.

Details

Microelectronics International, vol. 22 no. 3
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 8 June 2015

Shye-Nee Low, Shahrul Kamaruddin and Ishak Abdul Azid

The purpose of this paper is to investigate multiple criteria decision-making (MCDM) processes within a flow-line production-improvement activity. Investigation can lead…

Abstract

Purpose

The purpose of this paper is to investigate multiple criteria decision-making (MCDM) processes within a flow-line production-improvement activity. Investigation can lead to understanding of how a process improvement framework influences the decision and fulfillment of the potential to successfully change the operation process.

Design/methodology/approach

The improvement process selection (IPS) framework is built systematically by incorporating all related decision criteria with suitable tools required to select improvement alternatives. The process consists of three phases: identification, prediction, and selection. The IPS framework is validated through a case study of a company that was carrying out a flow-line production-improvement project.

Findings

The developed framework is used to prioritize the problem scope and select the solutions from various options. The case study illustrates the process through which the developed framework provided a systematic approach in identifying the solutions and achieving the desired performance improvement. Prediction result analysis shows the framework achieved sustainable process improvement changes and prevents management levels from higher risks in failure improvement. The feedback of the case study has verified the robustness of the framework.

Practical implications

Quantitative improvement tools, such as MCDM employed in the IPS framework are vital for better understanding of the improvement impact of changes. Thus, the improvement solution alternatives can be analyzed in more comprehensive ways by considering numerous performance metrics in order to select the best improvement alternatives.

Originality/value

The IPS framework can assist the company in determining optimal decisions in relation to selection of improvement alternatives. As a result, production performance can be affected positively.

Details

International Journal of Productivity and Performance Management, vol. 64 no. 5
Type: Research Article
ISSN: 1741-0401

Keywords

Article
Publication date: 1 March 2005

S.Y. Wang and K. Tai

This paper proposes a bar‐system graph representation for structural topology optimization using a genetic algorithm (GA).

Abstract

Purpose

This paper proposes a bar‐system graph representation for structural topology optimization using a genetic algorithm (GA).

Design/methodology/approach

Based on graph theory, a graph is first used to represent a skeletal structure consisting of joining paths in the design domain, each of which is represented by a chain subgraph with finite number of vertices. Based on the edges of this graph, a bar‐system representation is proposed to define all the bars and the resulting topology is obtained by mapping each bar with its corresponding thickness to the design domain which is discretized into a regular mesh. The design variables are thus reduced to the spatial distribution of the vertices and the thickness of each bar. This method combines the advantages of both continuum and ground structure optimization methods.

Findings

The overall procedure is applied to classical structural topology optimization problems and its good performance is illustrated in the numerical examples.

Originality/value

It is suggested that the present representation method is both physically meaningful and computationally effective in the framework of topological optimum design using GAs.

Details

Engineering Computations, vol. 22 no. 2
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 4 October 2021

Chong Hooi Lim, Mohd Zulkifly Abdullah, Ishak Abdul Aziz, Chu Yee Khor and Mohd Sharizal Abdul Aziz

This study aims to investigate the interaction of independent variables [Reynolds number (Re), thermal power and the number of ball grid array (BGA) packages] and the…

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Abstract

Purpose

This study aims to investigate the interaction of independent variables [Reynolds number (Re), thermal power and the number of ball grid array (BGA) packages] and the relation of the variables with the responses [Nusselt number ((Nu) ¯ ), deflection/FPCB’s length (d/L) and von Mises stress]. The airflow and thermal effects were considered for optimizing the Re of various numbers of BGA packages with thermal power attached on flexible printed circuit board (FPCB) for optimum cooling performance with least deflection and stress by using the response surface method (RSM).

Design/methodology/approach

Flow and thermal effects on FPCB with heat source generated in the BGA packages have been examined in the simulation. The interactive relationship between factors (i.e. Re, thermal power and number of BGA packages) and responses (i.e. deflection over FPCB length ratio, stress and average Nusselt number) were analysed using analysis of variance. RSM was used to optimize the Re for the different number of BGA packages attached to the FPCB.

Findings

It is important to understand the behaviour of FPCB when exposed to both flow and thermal effects simultaneously under the operating conditions. Maximum d/L and von Misses stress were significantly affected by all parametric factors whilst (Nu)¯ is significantly affected by Re and thermal power. Optimized Re for 1–3 BGA packages with maximum thermal power applied has been identified as 21,364, 23,858 and 29,367, respectively.

Practical implications

This analysis offers a better interpretation of the parameter control in FPCB with optimized Re for the use of force convection electronic cooling. Optimal Re could be used as a reference in the thermal management aspect in designing the BGA package.

Originality/value

This research presents the parameters’ effects on the reliability and heat transfer in FPCB design. It also presents a method to optimize Re for the different number of BGA packages attached to increase the reliability in FPCB’s design.

Article
Publication date: 21 September 2020

Steven Montana Widodo, Ririn Diar Astanti, The Jin Ai and T.M.A. Ari Samadhi

This paper tries to generalize business process improvement (BPI) methodology. It utilizes the seven-waste framework as an essential step in the methodology. While the…

Abstract

Purpose

This paper tries to generalize business process improvement (BPI) methodology. It utilizes the seven-waste framework as an essential step in the methodology. While the seven-waste concept is usually applied for manufacturing activities, this paper tries to explore the applicability of it to office-work activities. Also, this paper demonstrates that information technology can be used as a tool for reducing waste in the office-work.

Design/methodology/approach

A comprehensive literature review of BPI methodology studies was conducted in order to propose systematic flowcharts to represent the sequence of processes involved in each step of BPI methodology. The proposed flowcharts are applied to a case study in supply chain planning and allocation planning at a manufacturing company. The seven-waste framework is designed as part of the step, in which equivalency between the definition of waste found on the production floor and waste found in office work is presented.

Findings

The BPI methodology generally follows five steps: initialization, selection, design, implementation and evaluation. The seven-waste framework is effectively applied in the selection step. The case study shows that information technology can be used as a tool in business process improvement to reduce waste in the business process.

Practical implications

The case study indicates that the proposed framework and methodology are proven able to reduce the three key performance indicators. They are the number of steps from 54 to 24 (55% reduction), processing time from 890 min to 313.5 min (64% reduction) and the number of the manual process from 41 to 17 (59% reduction).

Originality/value

This paper proposes a generalization of BPI methodology, the seven-waste framework in the selection step of the BPI methodology, the seven-waste concept in office-work activity and the use of information technology for BPI by reducing waste in office-work activity.

Details

The TQM Journal, vol. 33 no. 4
Type: Research Article
ISSN: 1754-2731

Keywords

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