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1 – 10 of 90Amer Mecellem, Soufyane Belhenini, Douaa Khelladi and Caroline Richard
The purpose of this study is to propose a simplifying approach for modelling a reliability test. Modelling the reliability tests of printed circuit board (PCB)/microelectronic…
Abstract
Purpose
The purpose of this study is to propose a simplifying approach for modelling a reliability test. Modelling the reliability tests of printed circuit board (PCB)/microelectronic component assemblies requires the adoption of several simplifying assumptions. This study introduces and validates simplified assumptions for modeling a four-point bend test on a PCB/wafer-level chip scale packaging assembly.
Design/methodology/approach
In this study, simplifying assumptions were used. These involved substituting dynamic imposed displacement loading with an equivalent static loading, replacing the spherical shape of the interconnections with simplified shapes (cylindrical and cubic) and transitioning from a three-dimensional modelling approach to an equivalent two-dimensional model. The validity of these simplifications was confirmed through both quantitative and qualitative comparisons of the numerical results obtained. The maximum principal plastic strain in the solder balls and copper pads served as the criteria for comparison.
Findings
The simplified hypotheses were validated through quantitative and qualitative comparisons of the results from various models. Consequently, it was determined that the replacement of dynamic loading with equivalent static loading had no significant impact on the results. Similarly, substituting the spherical shape of interconnections with an equivalent shape and transitioning from a three-dimensional approach to a two-dimensional one did not substantially affect the precision of the obtained results.
Originality/value
This study serves as a valuable resource for researchers seeking to model accelerated reliability tests, particularly in the context of four-point bending tests. The results obtained in this study will assist other researchers in streamlining their numerical models, thereby reducing calculation costs through the utilization of the simplified hypotheses introduced and validated herein.
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Yang Liu, Xin Xu, Shiqing Lv, Xuewei Zhao, Yuxiong Xue, Shuye Zhang, Xingji Li and Chaoyang Xing
Due to the miniaturization of electronic devices, the increased current density through solder joints leads to the occurrence of electromigration failure, thereby reducing the…
Abstract
Purpose
Due to the miniaturization of electronic devices, the increased current density through solder joints leads to the occurrence of electromigration failure, thereby reducing the reliability of electronic devices. The purpose of this study is to propose a finite element-artificial neural network method for the prediction of temperature and current density of solder joints, and thus provide reference information for the reliability evaluation of solder joints.
Design/methodology/approach
The temperature distribution and current density distribution of the interconnect structure of electronic devices were investigated through finite element simulations. During the experimental process, the actual temperature of the solder joints was measured and was used to optimize the finite element model. A large amount of simulation data was obtained to analyze the neural network by varying the height of solder joints, the diameter of solder pads and the magnitude of current loads. The constructed neural network was trained, tested and optimized using this data.
Findings
Based on the finite element simulation results, the current is more concentrated in the corners of the solder joints, generating a significant amount of Joule heating, which leads to localized temperature rise. The constructed neural network is trained, tested and optimized using the simulation results. The ANN 1, used for predicting solder joint temperature, achieves a prediction accuracy of 96.9%, while the ANN 2, used for predicting solder joint current density, achieves a prediction accuracy of 93.4%.
Originality/value
The proposed method can effectively improve the estimation efficiency of temperature and current density in the packaging structure. This method prevails in the field of packaging, and other factors that affect the thermal, mechanical and electrical properties of the packaging structure can be introduced into the model.
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Zhaozhao Tang, Wenyan Wu, Po Yang, Jingting Luo, Chen Fu, Jing-Cheng Han, Yang Zhou, Linlin Wang, Yingju Wu and Yuefei Huang
Surface acoustic wave (SAW) sensors have attracted great attention worldwide for a variety of applications in measuring physical, chemical and biological parameters. However…
Abstract
Purpose
Surface acoustic wave (SAW) sensors have attracted great attention worldwide for a variety of applications in measuring physical, chemical and biological parameters. However, stability has been one of the key issues which have limited their effective commercial applications. To fully understand this challenge of operation stability, this paper aims to systematically review mechanisms, stability issues and future challenges of SAW sensors for various applications.
Design/methodology/approach
This review paper starts with different types of SAWs, advantages and disadvantages of different types of SAW sensors and then the stability issues of SAW sensors. Subsequently, recent efforts made by researchers for improving working stability of SAW sensors are reviewed. Finally, it discusses the existing challenges and future prospects of SAW sensors in the rapidly growing Internet of Things-enabled application market.
Findings
A large number of scientific articles related to SAW technologies were found, and a number of opportunities for future researchers were identified. Over the past 20 years, SAW-related research has gained a growing interest of researchers. SAW sensors have attracted more and more researchers worldwide over the years, but the research topics of SAW sensor stability only own an extremely poor percentage in the total researc topics of SAWs or SAW sensors.
Originality/value
Although SAW sensors have been attracting researchers worldwide for decades, researchers mainly focused on the new materials and design strategies for SAW sensors to achieve good sensitivity and selectivity, and little work can be found on the stability issues of SAW sensors, which are so important for SAW sensor industries and one of the key factors to be mature products. Therefore, this paper systematically reviewed the SAW sensors from their fundamental mechanisms to stability issues and indicated their future challenges for various applications.
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Rilwan Kayode Apalowo, Mohamad Aizat Abas, Muhamed Abdul Fatah Muhamed Mukhtar, Fakhrozi Che Ani and Mohamad Riduwan Ramli
This study aims to investigate the reliability issues of microvoid cracks in solder joint packages exposed to thermal cycling fatigue.
Abstract
Purpose
This study aims to investigate the reliability issues of microvoid cracks in solder joint packages exposed to thermal cycling fatigue.
Design/methodology/approach
The specimens are subjected to JEDEC preconditioning level 1 (85 °C/85%RH/168 h) with five times reflow at 270°C. This is followed by thermal cycling from 0°C to 100°C, per IPC-7351B standards. The specimens' cross-sections are inspected for crack growth and propagation under backscattered scanning electronic microscopy. The decoupled thermomechanical simulation technique is applied to investigate the thermal fatigue behavior. The impacts of crack length on the stress and fatigue behavior of the package are investigated.
Findings
Cracks are initiated from the ball grid array corner of the solder joint, propagating through the transverse section of the solder ball. The crack growth increases continuously up to 0.25-mm crack length, then slows down afterward. The J-integral and stress intensity factor (SIF) values at the crack tip decrease with increased crack length. Before 0.15-mm crack length, J-integral and SIF reduce slightly with crack length and are comparatively higher, resulting in a rapid increase in crack mouth opening displacement (CMOD). Beyond 0.25-mm crack length, the values significantly decline, that there is not much possibility of crack growth, resulting in a negligible change in CMOD value. This explains the crack growth arrest obtained after 0.25-mm crack length.
Practical implications
This work's contribution is expected to reduce the additional manufacturing cost and lead time incurred in investigating reliability issues in solder joints.
Originality/value
The work investigates crack propagation mechanisms of microvoid cracks in solder joints exposed to moisture and thermal fatigue, which is still limited in the literature. The parametric variation of the crack length on stress and fatigue characteristics of solder joints, which has never been conducted, is also studied.
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Vicente-Segundo Ruiz-Jacinto, Karina-Silvana Gutiérrez-Valverde, Abrahan-Pablo Aslla-Quispe, José-Manuel Burga-Falla, Aldo Alarcón-Sucasaca and Yersi-Luis Huamán-Romaní
This paper aims to present the novel stacked machine learning approach (SMLA) to estimate low-cycle fatigue (LCF) life of SAC305 solder across structural parts. Using the finite…
Abstract
Purpose
This paper aims to present the novel stacked machine learning approach (SMLA) to estimate low-cycle fatigue (LCF) life of SAC305 solder across structural parts. Using the finite element simulation (FEM) and continuous damage mechanics (CDM) model, a fatigue life database is built. The stacked machine learning (ML) model's iterative optimization during training enables precise fatigue predictions (2.41% root mean square error [RMSE], R2 = 0.975) for diverse structural components. Outliers are found in regression analysis, indicating potential overestimation for thickness transition specimens with extended lifetimes and underestimation for open-hole specimens. Correlations between fatigue life, stress factors, nominal stress and temperature are unveiled, enriching comprehension of LCF, thus enhancing solder behavior predictions.
Design/methodology/approach
This paper introduces stacked ML as a novel approach for estimating LCF life of SAC305 solder in various structural parts. It builds a fatigue life database using FEM and CDM model. The stacked ML model iteratively optimizes its structure, yielding accurate fatigue predictions (2.41% RMSE, R2 = 0.975). Outliers are observed: overestimation for thickness transition specimens and underestimation for open-hole ones. Correlations between fatigue life, stress factors, nominal stress and temperature enhance predictions, deepening understanding of solder behavior.
Findings
The findings of this paper highlight the successful application of the SMLA in accurately estimating the LCF life of SAC305 solder across diverse structural components. The stacked ML model, trained iteratively, demonstrates its effectiveness by producing precise fatigue lifetime predictions with a RMSE of 2.41% and an “R2” value of 0.975. The study also identifies distinct outlier behaviors associated with different structural parts: overestimations for thickness transition specimens with extended fatigue lifetimes and underestimations for open-hole specimens. The research further establishes correlations between fatigue life, stress concentration factors, nominal stress and temperature, enriching the understanding of solder behavior prediction.
Originality/value
The authors confirm the originality of this paper.
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Didier Marquis, Felipe Reinoso Carvalho and Gaëlle Pantin-Sohier
Aversion linked to disgust and neophobia is the primary reason for human reluctance towards edible insects as a sustainable food source. Stimulating positive emotions may overcome…
Abstract
Purpose
Aversion linked to disgust and neophobia is the primary reason for human reluctance towards edible insects as a sustainable food source. Stimulating positive emotions may overcome these mental barriers. Cute visuals and claims on product packaging can trigger positive affective responses in consumers whilst modulating taste expectations. This study investigated how these elements influence emotions, perceptions and attitudes towards insect-based foods.
Design/methodology/approach
An online cross-cultural study involving French (n = 747) and Colombian (n = 695) consumers was conducted using two insect-based products: chips (hedonic) and bread (functional). Ten visual packaging variations were created per product, emphasising palatability, sustainability, nutrition and popularity (plus a control: no claim) affixed to the image of a cute anthropomorphic cricket or its silhouette. Visual appreciation and associations were assessed along with the participants' degree of food variety seeking, familiarity with entomophagy and openness to consuming edible insects.
Findings
Differences were reported in emotions, perceptions and attitudes based on the combination of packaging elements, product type and consumer segments. The findings suggest that food marketers should use cute insect depictions linked to palatability-focussed claims to alleviate young French adults' reluctance towards insect-based foods (IFs). Colombians responded better to pro-social claims and neutrally to cuteness.
Practical implications
The results should be valuable to stakeholders seeking to enhance food marketing strategies related to IFs amongst target consumer segments.
Originality/value
This study is the first to assess how baby schema cuteness induces emotional changes towards IFs and how it affects perceptions and attitudes amongst distinct populations and age segments.
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Upon completion of the case study, the students will be able to find the challenges and underlying structures that cause the problem; the students will be able to identify the…
Abstract
Learning outcomes
Upon completion of the case study, the students will be able to find the challenges and underlying structures that cause the problem; the students will be able to identify the dynamic variables and develop the interconnection and interlinkages among the time-delayed variables to build the story of the business case; the students could develop the block diagram and could build the system dynamics model using the simulation software STELLA, and if they do not have the simulation software, even then they could have a mental model to understand the problem well; the system dynamics students can design the policies to make the system better behaved and recommend solutions; and the students could make mind maps and develop the mental model and could recommend solutions and way forward to overcome the challenges and solve the issues.
Case overview/synopsis
Tradeasia is a small-scale manufacturing firm that had started its business activities near Sundar Industrial Estate, Raiwind, in September 2007. The company’s prime focus was to buy the potato starch from chips manufacturing companies and, then, extract the potato starch from the waste potato using its own machinery and sell it as a sizing agent to textile mills. Quality characteristics in terms of better millage and enhanced gullibility made it compatible with Rafhan corn-based starch. The major challenge linked to potato starch was its degree of wetness; the potato starch either extracted from rotten potato or procured from the potato chips manufacturing companies had a high degree of wetness and moisture content. Wet potato starch sometimes had more than 60% moisture content, which was really a challenge. Owing to the high degree of wetness, the wet starch was prone to fungus growth, and within hours, the fungus created toxins if it was not dried immediately, and then after 24 h, toxins acquired a black colour, and they became hardened like pebbles. The starch then was unusable even for sizing purposes for textile products. Reduction in the degree of wetness was really a big challenge and demanded prompt action and high productivity of the operational staff to make that product dry for sale purposes. This was the biggest challenge that ended up in huge inventories of wet starch. Capacity constraints and operational inefficiency killed the company’s productivity and affected the company’s profit.
Complexity academic level
This case study is written and developed for MBA and MS-level supply chain students of the system dynamics course or those studying management of supply chain complexities. This case study discusses the operational challenges while running the business; huge inventories, capacity constraints and inefficiency in production operations were the challenges associated with almost all manufacturing industries. This case study discussed not only why such challenges are appearing in the business but also the solution that resided in the wisdom shared by the employees in the board meeting. An integrated system dynamics model could be used to design the policies to overcome such challenges. Even the block diagram of the model and causal loop diagram could help to conceptualize the problem and explore the way forward.
Supplementary materials
Teaching notes are available for educators only.
Subject code
CSS 7: Management science.
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In this paper, we evaluated the impact of the US “Chip Act” on the participation of the Chinese electronics industry in the global value chain based on the dynamic CGE model. This…
Abstract
Purpose
In this paper, we evaluated the impact of the US “Chip Act” on the participation of the Chinese electronics industry in the global value chain based on the dynamic CGE model. This is a meaningful attempt to use the GTAP-VA model to analyze the electronics industry in China.
Design/methodology/approach
We employ a Dynamic GTAP-VA Model to quantitatively evaluate the economic repercussions of the “Chip Act” on the Chinese electronic industries' GVC participation from 2023 to 2040.
Findings
The findings depict a discernible contraction in China’s electronic sector by 2040, marked by a −2.95% change in output, a −3.50% alteration in exports and a 0.45% increment in imports. Concurrently, the U.S., EU and certain Asian economies exhibit expansions within the electronic sector, indicating a GVC realignment. The “Chip Act” implementation precipitates a significant divergence in GVC participation across different countries and industries, notably impacting the electronics sector.
Research limitations/implications
Through a meticulous temporal analysis, this manuscript unveils the nuanced economic shifts within the GVC, substantially bridging the empirical void in existing literature. This narrative accentuates the profound implications of policy regulations on global trade dynamics, contributing to the discourse on international economic policy and industry evolution.
Practical implications
We evaluated the impact of the US “Chip Act” on the participation of the Chinese electronics industry in the global value chain based on the dynamic CGE model. This is a meaningful attempt to use the GTAP-VA model to analyze the electronics industry in China.
Social implications
The interaction between policy regulations and global value chain (GVC) dynamics is pivotal in understanding the contemporary global trade framework, especially within technology-driven sectors. The US “Chips Act” represents a significant regulatory milestone with potential ramifications on the Chinese electronic industries' engagement in the GVC.
Originality/value
The significance of this paper is that it quantifies for the first time the impact of the US Chip Act on the GVC participation index of East Asian countries in the context of US-China decoupling. With careful consideration of strategic aspects, this paper substantially fills the empirical gap in the existing literature by presenting subtle economic changes within GVCs, highlighting the profound implications of policy regulation on global trade dynamics.
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This level of sophistication is not the most advanced on the market: Apple’s M3 chips, as well as the A17 powering the most recent version of the iPhone, use 3nm chips.
Details
DOI: 10.1108/OXAN-DB285166
ISSN: 2633-304X
Keywords
Geographic
Topical
Saima Sattar and Nauman Khalid
Potato-based snacks (PBS) are widely popular among people of all age groups despite known negative health aspects. University students, due to their busy routines and less…
Abstract
Purpose
Potato-based snacks (PBS) are widely popular among people of all age groups despite known negative health aspects. University students, due to their busy routines and less familiarity with diets are more prone to selecting unhealthy meals and snacks. The study aims to explore the outlook of university students regarding their consumption of processed and packaged PBS in their daily lives and compares gender’s PBS choices with dietary habits and food environment.
Design/methodology/approach
A total of 122 students from various universities across Pakistan were included in this study. The data were collected using a structured questionnaire and distributed using the snowball method.
Findings
The university students showed a significant difference in their living habits (p = 0.016), where 25.4% of enrolled male students were hostellers as compared to females (14.8%). Significant differences were noticed in choosing PBS that further depends on the familiarity of the product, (p = 0.030), where 9.0% of female students rated familiarity with the product as being important while 20.5% of males responded familiarity as a critical factor. Studying the usual location/point of purchase for a PBS, a significant difference was observed (p = 0.008%) where more male students (27.9%) choose to buy their PBS from a local convenience store as compared to female students (18.9%). Female students (13.1%) would rather choose to buy their PBS on their weekly grocery runs.
Originality/value
This study concluded that female and male students’ attitudes regarding the consumption of PBS were almost the same regardless of environment and brand repute.
Highlights
Dietary behavioral studies of consumption of PBS
The environment and brand reputation have no impact on the consumption of PBS
Gender differences have no impact on the selection of PBS
Awareness and healthy selection of PBS are critical factors that need to be focused
Dietary behavioral studies of consumption of PBS
The environment and brand reputation have no impact on the consumption of PBS
Gender differences have no impact on the selection of PBS
Awareness and healthy selection of PBS are critical factors that need to be focused
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