T. Alander, I. Suominen, P. Heino and E. Ristolainen
The solder joint reliability of FC components on organic substrates is questionable unless underfill is used to relieve the thermal strains. Besides the mechanical protection…
Abstract
The solder joint reliability of FC components on organic substrates is questionable unless underfill is used to relieve the thermal strains. Besides the mechanical protection, underfill provides the solder and I.C. surface with protection against the environment. Underfilling is however, time‐consuming and expensive. In an electrical sense, the underfill has no beneficial function and should, therefore, be considered as a ballast in an electronic assembly. However, to obtain a satisfactory level of reliability without underfill some novel methods are required. Wafer thinning is often performed to fit a die into a thin package, e.g. in smart cards. In this paper, the issue of thinning a package is studied utilizing 3D finite element method models. Various die and board thicknesses are evaluated with respect to their effect on the reliability of FC solder bumps. In addition, a novel idea to increase the joint reliability is studied.
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The purpose of this study is to investigate the effect of chip and substrate thickness on the thermal cycling reliability of flip chip joints assembled with anisotropic conductive…
Abstract
Purpose
The purpose of this study is to investigate the effect of chip and substrate thickness on the thermal cycling reliability of flip chip joints assembled with anisotropic conductive adhesives (ACA) on FR‐4 substrates.
Design/methodology/approach
Four test lots were assembled with two substrates and two test chips. The thicknesses of the substrates were 710 and 100 μm and the thicknesses of the chips were 480 and 80 μm. To study the effect of the bonding pressure each test lot contained four test series bonded with four different bonding pressures. The reliability of the test samples was studied using a temperature cycling test.
Findings
The reliability of the test lots varied widely during the test. The test lot with a thin substrate and thin chip demonstrated considerably better reliability than the other test lots. In addition, the test lots had different failure mechanisms. After the test delamination was found in every test lot except the one assembled with the thin chip and the thin substrate.
Originality/value
The work shows that the thermal cycling reliability of ACA flip chip joints can be markedly increased by using thinned chips or reducing the thickness of the substrate.
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Veronika Šlapáková Losová and Ondřej Dvouletý
The resource crisis in healthcare can be alleviated by engaging external stakeholders and resources in healthcare delivery. The authors use value and open innovation concepts to…
Abstract
Purpose
The resource crisis in healthcare can be alleviated by engaging external stakeholders and resources in healthcare delivery. The authors use value and open innovation concepts to understand what motivates the stakeholders to join the healthcare innovation ecosystem and what value such an ecosystem brings to healthcare.
Design/methodology/approach
A systematic literature review following the PRISMA framework method was applied to reach the research objective. Out of a total of 509 identified articles published till 2021, 25 were selected as relevant for this review.
Findings
Six categories of actors were identified, including innovation intermediaries, which were so far neglected in the healthcare innovation literature. Furthermore, patients, healthcare providers, innovation suppliers, investors and influencers were described. The authors also distinguished internal and external stakeholders. The authors show why and how open innovation projects contribute to involving external stakeholders and resources in healthcare delivery by contributing to patient autonomy, relationship building, knowledge transfer, improving collaborative mindset and culture, advancing know-how and bringing additional finances.
Originality/value
This article is the first one to systematically describe the value of open innovation in healthcare. The authors challenge the positivist approach in value presented by value-based healthcare. The authors show how openness contributes to addressing the resource crisis by involving new stakeholders and resources in the care delivery process.
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This paper gives a bibliographical review of the finite element and boundary element parallel processing techniques from the theoretical and application points of view. Topics…
Abstract
This paper gives a bibliographical review of the finite element and boundary element parallel processing techniques from the theoretical and application points of view. Topics include: theory – domain decomposition/partitioning, load balancing, parallel solvers/algorithms, parallel mesh generation, adaptive methods, and visualization/graphics; applications – structural mechanics problems, dynamic problems, material/geometrical non‐linear problems, contact problems, fracture mechanics, field problems, coupled problems, sensitivity and optimization, and other problems; hardware and software environments – hardware environments, programming techniques, and software development and presentations. The bibliography at the end of this paper contains 850 references to papers, conference proceedings and theses/dissertations dealing with presented subjects that were published between 1996 and 2002.
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Chien-Yi Huang, Li-Cheng Shen, Ting-Hsuan Wu and Christopher Greene
This paper aims to discuss the key factors affecting the quality characteristics, such as the number of solder balls, the spread distance of residual underfill and the completion…
Abstract
Purpose
This paper aims to discuss the key factors affecting the quality characteristics, such as the number of solder balls, the spread distance of residual underfill and the completion time of the underfilling.
Design/methodology/approach
The Taguchi method is applied to configure the orthogonal table and schedule and execute the experiment. In addition, principal components analysis is used to obtain the points. Then, based on gray relational analysis and the technique for order preference by similarity to ideal solution, the closeness between each quality characteristic and the ideal solution is adopted as the basis for evaluating the quality characteristics.
Findings
The optimal parameter combination is proposed, which includes 4 dispensing (11 mg/dispensing), a “half flow” interval state, 80°C preheating module PCB board and an L-shaped dispensing path and verification testing is performed.
Originality/value
For vehicles and handheld electronic products, solder joints that connect electronic components to printed circuit boards may be cracked due to collision, vibration or falling. Consequently, solder balls are closely surrounded and protected by the underfill to improve joint strength and resist external force factors, such as collision and vibration. This paper addresses the defects caused during the second reflow process of a vehicle electronic communication module after the underfilling process.
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Sami T. Nurmi, Janne J. Sundelin, Eero O. Ristolainen and Toivo K. Lepistö
To study the behaviour of voids in PBGA solder joints and their influence on the lifetime of lead‐free solder joints.
Abstract
Purpose
To study the behaviour of voids in PBGA solder joints and their influence on the lifetime of lead‐free solder joints.
Design/methodology/approach
The behaviour of voids was studied using micro via and land pad PWBs, PBGA components, and by measuring voids in the solder joints. The lifetimes of solder joints were tested using accelerated temperature tests.
Findings
Number of factors affecting the solder joint lifetimes were found. The voids were discovered to have a significantly large influence on the solder joints.
Practical implications
The findings can be used to achieve better soldering results, methods, and designs.
Originality/value
In this paper, the effect and the behaviour of voids were studied profoundly. The findings can be valuable to researchers and process personnel.
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Darlene Himick, Gustav Johed and Christoph Pelger
The purpose of this Editorial is to reflect on the potentials and challenges of qualitative research in financial accounting and introduce the four papers included in this Special…
Abstract
Purpose
The purpose of this Editorial is to reflect on the potentials and challenges of qualitative research in financial accounting and introduce the four papers included in this Special Issue.
Design/methodology/approach
The authors draw on and discuss extant literature and the papers included in the Special Issue to develop our assessment of the current state of the field of qualitative financial accounting research and possible future paths ahead.
Findings
The authors observe that qualitative research on financial accounting is still an emerging field with substantial further research potential.
Research limitations/implications
The authors outline future potentials for qualitative accounting research.
Originality/value
This Editorial contributes to studies on the state of academic research in (financial) accounting.
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Isto Huvila, Åsa Cajander, Jonas Moll, Heidi Enwald, Kristina Eriksson-Backa and Hanife Rexhepi
Data from a national patient survey (N = 1,155) of the Swedish PAEHR “Journalen” users were analysed, and an extended version of the theory of technological frames was developed…
Abstract
Purpose
Data from a national patient survey (N = 1,155) of the Swedish PAEHR “Journalen” users were analysed, and an extended version of the theory of technological frames was developed to explain the variation in the technological and informational framing of information technologies found in the data.
Design/methodology/approach
Patient Accessible Electronic Health Records (PAEHRs) are implemented globally to address challenges with an ageing population. However, firstly, little is known about age-related variation in PAEHR use, and secondly, user perceptions of the PAEHR technology and the health record information and how the technology and information–related perceptions are linked to each other. The purpose of this study is to investigate these two under-studied aspects of PAEHRs and propose a framework based on the theory of technological frames to support studying the second aspect, i.e. the interplay of information and technology–related perceptions.
Findings
The results suggest that younger respondents were more likely to be interested in PAEHR contents for general interest. However, they did not value online access to the information as high as older ones. Older respondents were instead inclined to use medical records information to understand their health condition, prepare for visits, become involved in their own healthcare and think that technology has a much potential. Moreover, the oldest respondents were more likely to consider the information in PAEHRs useful and aimed for them but to experience the technology as inherently difficult to use.
Research limitations/implications
The sample excludes non-users and is not a representative sample of the population of Sweden. However, although the data contain an unknown bias, there are no specific reasons to believe that it would differently affect the survey's age groups.
Practical implications
Age should be taken into account as a key factor that influences perceptions of the usefulness of PAEHRs. It is also crucial to consider separately patients' views of PAEHRs as a technology and of the information contained in the EHR when developing and evaluating existing and future systems and information provision for patients.
Social implications
This study contributes to bridging the gap between information behaviour and systems design research by showing how the theory of technological frames complemented with parallel informational frames to provide a potentially powerful framework for elucidating distinct conceptualisations of (information) technologies and the information they mediate. The empirical findings show how information and information technology needs relating to PAEHRs vary according to age. In contrast to the assumptions in much of the earlier work, they need to be addressed separately.
Originality/value
Few earlier studies focus on (1) age-related variation in PAEHR use and (2) user perceptions of the PAEHR technology and the health record information and how the technology and information–related perceptions are linked to each other.
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For such a small country Finland has a strong programme of R&D in assembly processes. In this article, projects to assemble water taps and wire harnesses are described.
Liyu Yang, Rui Niu, Jinsong Xie, Bin Qian, Baishi Song, Qingan Rong and Joseph Bernstein
In today's electronic package development cycle, activities are managed by multiple participants in the supply chain, which might have different quality and reliability impacts to…
Abstract
Purpose
In today's electronic package development cycle, activities are managed by multiple participants in the supply chain, which might have different quality and reliability impacts to the end product. As a result, the reliability risk is much higher for companies who do not have insight into and/or control over the products received. The purpose of this paper is to show how design‐for‐reliability (DFR) approaches will come into play to manage the risk.
Design/methodology/approach
In this paper, DFR approaches for package development will be discussed from the perspective of the original equipment manufacturers (OEMs). DFR practices through the package development cycle will be described based on key development modules. A case study for flip chip ball gris array package development using an advanced Cu/Low‐k silicon technology will be presented. Key measures to help control the quality and improve the reliability will be presented.
Findings
The proposed methodology significantly improves component and package reliability through the engagement in design, manufacturing, assessment and system evaluation.
Originality/value
The paper discusses the research results and the proposed DFR methodology will be helpful for fabless design houses, electronics manufacturing service (EMS) partners in the supply chain, and OEMs to manage the reliability of the products.