The purpose of this paper is to identify the critical parameters that influence ball grid array and chip size package fatigue life in a random vibration environment by using a…
Abstract
Purpose
The purpose of this paper is to identify the critical parameters that influence ball grid array and chip size package fatigue life in a random vibration environment by using a design of experimental (DOE) approach using simulation results.
Design/methodology/approach
The use of DOE and analysis of variation to identify the critical parameters and a response surface to generate a functional form for global modeling would be determined. Once the global modeling’s functional form was known, it can be used as boundary condition, which would be input to a local model. Knowing the critical stress, one would estimate the fatigue life from a damage model. It is the curvature of the printed wiring board in the region of the component of interest that is driving the component’s solder joint damage. The approach in this present work involves global-local modeling approaches. In the global model approach, the vibration response of the printed circuit board (PCB) will be determined.
Findings
This global model will give the response of the PCB at specific component locations of interest. This response is then fed into a local stress analysis for accurate assessment of the critical stresses in the solder joints of interest. The stresses are then fed into a fatigue damage model to predict the life.
Originality/value
The analysis proposed in this paper uses a failure type approach to damage analysis and involves global and local model approaches.
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The purpose of this study was to investigate the changes in solder joint stress when subjected to mechanical bending. The analytical theory pertaining to the stresses in the…
Abstract
Purpose
The purpose of this study was to investigate the changes in solder joint stress when subjected to mechanical bending. The analytical theory pertaining to the stresses in the solder joint between the components (including the molding compound, the chip and the substrate) was described, and the printed circuit board (PCB) with a discontinuity function when the PCB assembly is subjected to mechanical bending was developed. Thus, the findings reported here may lead to a better understanding of the solder joint failure based on the Physics of Failure model.
Design/methodology/approach
This paper discusses the analytical model for calculating the stress in solder joints, as well as presents a simulation model that can be used for calculating the strain energy density of solder joint. First, the multilayer plate theory is used in discussing the composite material for the component, including the molding compound, the silicon chip and the substrate, or the PCB, including the copper layers, the fiber and the epoxy. Finally, the complete structure of the analytical model developed as a part of this current work is presented.
Findings
For the analytical model of multilayer structures in which the interconnection layer is discrete, mechanical bending has been modeled with respect to varying silicon chip length. The analytical model that describes the stress of the outermost solder joint experiences is chosen, as this is the typical solder joint failure. The analytical model can be applied to discrete solder joints, which are evaluated by calculating the matrix form. Owing to its use of the matrix equation, the analytical model can be highly combinatorial and thus more capable of calculating the solution.
Research limitations/implications
The analytical solution based on a simple concept was presented and validated using the finite element model for the stress experienced by solder joints subjected to mechanical bending. To verify that the simulation represents a real PCB case, the authors use the finite element method (FEM) to compare their case with the multilayer plate theory. Owing to the good agreement between the theory and simulation results, the authors conclude that the multilayer plate theory can be correctly applied in multilayer PCB and be used in an analytical model for the PCB assembly subjected to mechanical bending.
Practical implications
Owing to the good agreement between the theory and simulation results, the authors conclude that the multilayer plate theory can be correctly applied in multilayer PCB and be used in an analytical model for the PCB assembly subjected to mechanical bending.
Social implications
The analytical model is validated with the FEM model and provides the way to physically examine the solder joint failure mechanism. In this paper, the analytical model is developed as a means to assess the solder joint stress subjected to mechanical bending.
Originality/value
The analytical model treats the solder joint as discrete and has been successfully validated against the finite element model. The complete structure model (the second analytical model) is presented to discuss the effects of varying silicon chip length on the normal stress in solder joints. When the silicon chip length exceeds to 80 per cent of the total package length, the stress of the outermost solder joint increases rapidly. The design analysis findings have suggested that the failure of the outermost solder joint subjected to mechanical bending on the PCB assembly can be reduced by analyzing the analytical model.
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This paper aims to develop the thermal resistance network model based on the heat dissipation paths from the multi-die stack to the ambient and takes into account the composite…
Abstract
Purpose
This paper aims to develop the thermal resistance network model based on the heat dissipation paths from the multi-die stack to the ambient and takes into account the composite effects of the thermal spreading resistance and one-dimensional (1D) thermal resistance. The thermal spreading resistance comprises majority of the thermal resistance when heat flows in the horizontal direction of a large plate. The present study investigates the role of determining the temperature increase compared to the thermal resistances intrinsic to the 3D technology, including the thermal resistances of bonding layers and through silicon vias (TSVs).
Design/methodology/approach
This paper presents an effective method that can be applied to predict the thermal failure of the heat source of silicon chips. An analytical model of the 3D integrated circuit (IC) package, including the full structure, is developed to estimate the temperature of stacked chips. Two fundamental theories are used in this paper – Laplace’s equation and the thermal resistance network – to calculate 1D thermal resistance and thermal spreading resistance on the 3D IC package.
Findings
This paper provides a comprehensive model of the 3D IC package, thus improving the existing analytical approach for predicting the temperature of the heat source on the chip for the 3D IC package.
Research limitations/implications
Based on the aforementioned shortcomings, the present study aims to determine if the use of an analytical resistance model would improve the handling of a temperature increase on the silicon chips in a 3D IC package. To achieve this aim, a simple rectangular plate is utilized to analyze the temperature of the heat source when applying the heat flux on the area of the heat source. Next, the analytical model of a pure plate is applied to the 3D IC package, and the temperature increase is analyzed and discussed.
Practical implications
The main contribution of this paper is the use of a simple concept and a theoretical resistance network model to improve the current understanding of thermal failure by redesigning the parameters or materials of a printed circuit board.
Social implications
In this paper, an analytical model of a 3D IC package was proposed based on the calculation of the thermal resistance and the analysis of the network model.
Originality/value
The aim of this work was to estimate the mean temperature of the silicon chips and understand the heat convection paths in the 3D IC package. The results reveal these phenomena of the complete structure, including TSV and bump, and highlight the different thermal conductivities of the materials used in creating the 3D IC packages.
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Mei-Ling Cheng, Ching-Wu Chu and Hsiu-Li Hsu
This paper aims to compare different univariate forecasting methods to provide a more accurate short-term forecasting model on the crude oil price for rendering a reference to…
Abstract
Purpose
This paper aims to compare different univariate forecasting methods to provide a more accurate short-term forecasting model on the crude oil price for rendering a reference to manages.
Design/methodology/approach
Six different univariate methods, namely the classical decomposition model, the trigonometric regression model, the regression model with seasonal dummy variables, the grey forecast, the hybrid grey model and the seasonal autoregressive integrated moving average (SARIMA), have been used.
Findings
The authors found that the grey forecast is a reliable forecasting method for crude oil prices.
Originality/value
The contribution of this research study is using a small size of data and comparing the forecasting results of the six univariate methods. Three commonly used evaluation criteria, mean absolute error (MAE), root mean squared error (RMSE) and mean absolute percent error (MAPE), were adopted to evaluate the model performance. The outcome of this work can help predict the crude oil price.
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Ming-Hsuan Wu, Weerapon Thongma, Winitra Leelapattana and Mei-Ling Huang
This study seeks to investigate issues transpiring in green hotels from a human resource perspective which is unlike most green-hotel studies centering on consumer behavioral…
Abstract
This study seeks to investigate issues transpiring in green hotels from a human resource perspective which is unlike most green-hotel studies centering on consumer behavioral subjects. It hypothesizes that the employees’ green ability consisting of environmental awareness, environmental knowledge, and environmental skill creates a positive impact on hotels’ green ability and ultimately on the overall performance of hotels. Using alumni from a tourism and hospitality program, this study collects 233 responses from a structured questionnaire survey. The findings indicate that hotel employees approximately contribute toward a fifth of the hotels’ ability to implement greener practices.
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Allan K.K. Chan and Yue‐Yuan Huang
Reports a study of 1,304 Chinese brand names of ten types of products in China. These brand names are content analyzed following a linguistic approach which the authors developed…
Abstract
Reports a study of 1,304 Chinese brand names of ten types of products in China. These brand names are content analyzed following a linguistic approach which the authors developed from their earlier studies. The ten types of brand names are presented in three broad categories representing the three different developing stages of the consumer product industry in China: brands of traditional products (illustrated by matches and spirits), brands of traditional products with current development (illustrated by bicycles, shoes, and toothpastes), and brands of new and modern products (illustrated by cosmetics, soft drinks, washing machines, refrigerators and TV sets). The conclusion drawn from the analysis is that one of the variables in determining how linguistic principles are being applied to Chinese brand naming is the respective stages of development of such products in the context of the Chinese market economy.
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Shih-Shuo Yeh, Anestis K. Fotiadis, Mei-Ling Huang and Tzung-Cheng Huan
Using the Analytical Hierarchy Process, this study aims to identify organizational and market factors that prevent hoteliers from adopting greener management systems. This study…
Abstract
Using the Analytical Hierarchy Process, this study aims to identify organizational and market factors that prevent hoteliers from adopting greener management systems. This study first constructs a list of critical factors based on expert judgments reported in the literature and the responses from a select group of experienced managers. Then, the list is further refined by six hotel managers who consolidate the factors, which results in four categories explained by 20 items. Subsequently, this study draws from surveys on an expert panel consisting of 20 study subjects who are familiar with hotel operations. The survey results show that hoteliers’ abilities to create a greener image are the most important factor influencing the managers’ decisions to adopt environmentally friendly management schemes. Nevertheless, their motivation of adopting a green strategy seems to be associated with a marketing strategy, instead of generic environmental stewardship.
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May Mei Ling Wong, Ka Hing Lau and Chad Wing Fung Chan
COVID-19 has changed the way we teach and learn, including service-learning (S-L). This study examines the impacts of the work-from-home (WFH) mode on the work performance and…
Abstract
Purpose
COVID-19 has changed the way we teach and learn, including service-learning (S-L). This study examines the impacts of the work-from-home (WFH) mode on the work performance and learning outcomes of student interns on an eight-week S-L internship programme, and the key factors in terms of its success.
Design/methodology/approach
A qualitative research methodology is adopted by interviewing nine student interns and four supervisors from three community partner organisations (CPOs) to understand their experiences of how the WFH mode has impacted intern work performance and learning outcomes. Thematic analysis is used for the data analysis.
Findings
The interns uncover a number of negative WFH impacts on the S-L internship, including ineffective communication and management practice, low work efficiency and quality, a lack of task variety and learning opportunities and distractions in the home environment. Furthermore, five critical factors for WFH success are also identified, including prior preparation, effective communication systems, personal motivators at work, the nature of the job in relation to it being suited to the WFH mode, and organisational support.
Originality/value
The study examines impacts on student work performance and learning outcomes in an S-L summer internship programme operating under the WFH mode as a result of the COVID-19 pandemic. Key success factors and practical recommendations have been developed for enhancing the future success of S-L internships operating under the WFH mode.
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Min-Shi Liu, Mei-Ling Wang and Chun Hsien Lee
The purpose of this study is to examine the indirect impact of job demands on recovery self-efficacy via the mediation of job burnout. The study also investigates the moderating…
Abstract
Purpose
The purpose of this study is to examine the indirect impact of job demands on recovery self-efficacy via the mediation of job burnout. The study also investigates the moderating effects of school-to-work facilitation and psychological detachment in the indirect relationship between job demands and recovery self-efficacy.
Design/methodology/approach
The study recruited and surveyed 263 employed graduate students in the executive master of business administration program in Taiwan. Regression analysis was used to examine the proposed relationships.
Findings
The results showed that job burnout mediated the relationship between job demands and recovery self-efficacy. The relationship was weaker when school-to-work facilitation and psychological detachment were high.
Originality/value
This study confirms the indirect effects of job demands on recover self-efficacy through job burnout and provides new insights into the role of school-to-work facilitation and psychological detachment to enhance the recovery in the JD-R model.