J. Lau, Y.‐H. Pao, C. Larner, R. Govila, S. Twerefour, D. Gilbert, S. Erasmus and S. Dolot
The reliability of 0.4 mm pitch, 28 mm body size, 256‐pin plastic quad flat pack (QFP) no‐clean and water‐clean solder joints has been studied by temperature cycling and…
Abstract
The reliability of 0.4 mm pitch, 28 mm body size, 256‐pin plastic quad flat pack (QFP) no‐clean and water‐clean solder joints has been studied by temperature cycling and analytical analysis. The temperature cycling test was run non‐stop for more than 6 months, and the results have been presented as a Weibull distribution. A unique temperature cycling profile has been developed based on the calculated lead stiffness, elastic and creep strains in the solder joint, and solder data. Also, the thermal fatigue life of the solder joints has been estimated and correlated with experimental results. Furthermore, a failure analysis of the solder joints has been performed using scanning electron microscopy (SEM). Finally, a quantitative comparison between the no‐clean and water‐clean QFP solder joints has been presented.
J. Lau, S. Golwalkar, P. Boysan, R. Surratt, R. Forhringer and S. Erasmus
The reliability of 0.5 mm pitch, 32‐pin thin small outline package (TSOP) solder joints has been studied by experimental temperature cycling and a cost‐effective 3‐D non‐linear…
Abstract
The reliability of 0.5 mm pitch, 32‐pin thin small outline package (TSOP) solder joints has been studied by experimental temperature cycling and a cost‐effective 3‐D non‐linear finite element analysis. Temperature cycling results have been presented as a Weibull distribution, and an acceleration factor has been established for predicting the failure rate at operating conditions. Thermal fatigue life of the corner solder joints has been estimated based on the calculated plastic strain, Coffin‐Manson law and isothermal fatigue data on solders. A correlation between the experimental and analytical results has also been made. Furthermore, failure analysis of the solder joints has been performed using scanning electron microscopy (SEM) and an optical method. Finally, a quantitative comparison between the Type‐I and Type‐II TSOP solder joints has been presented.
J. Lau, R. Govila, C. Larner, Y.‐H. Pao, S. Erasmus, S. Dolot, M. Jalilian and M. Lancaster
Solvent‐clean and no‐clean mass reflow processes of 0.4 mm pitch, 28 mm body size, 256‐pin fine pitch quad flat packs (QFPs) are presented. Emphasis is placed on fine pitch…
Abstract
Solvent‐clean and no‐clean mass reflow processes of 0.4 mm pitch, 28 mm body size, 256‐pin fine pitch quad flat packs (QFPs) are presented. Emphasis is placed on fine pitch parameters such as printed circuit board (PCB) design, solder paste selection, stencil design, printing technology, component placement, mass reflow, cleaning and inspection. Furthermore, cross‐sections of component/PCB assemblies from both processes have been thoroughly studied using scanning electron microscopy (SEM).
J. Lau, S. Leung, R. Subrahmanyan, D. Rice, S. Erasmus and C.Y. Li
In this study, the reliability of solder joints and plated‐through hole copper pads/barrels of pin grid array assemblies under rework condition has been determined by fatigue…
Abstract
In this study, the reliability of solder joints and plated‐through hole copper pads/barrels of pin grid array assemblies under rework condition has been determined by fatigue experiments. The cross‐sections of the re‐worked PGA assemblies (before and after fatigue tests) are also provided for a better understanding of the failure mechanisms of the composite structure. Furthermore, the load‐drop curves of the PGA interconnects for up to three reworks are provided for a better estimate of their fatigue life.
Robert J. Nathan, Paul H.P. Yeow and San Murugesan
This paper aims to report on a web usability study and to identify and prioritise key web interface usability factors (WIUFs) for web sites of 36 student‐related online services…
Abstract
Purpose
This paper aims to report on a web usability study and to identify and prioritise key web interface usability factors (WIUFs) for web sites of 36 student‐related online services categorised into three groups: personal services, purchase services and study‐related web sites.
Design/methodology/approach
In this study, involving 400 student internet users (SIUs), 12,310 data points were collected and analysed using a multiple linear regression test. Seven WIUFs were tested: use of colour and font (UCF), use of graphics and multimedia (UGM), clarity of goals in web site (CGW), trustworthiness of web site (TOW), interactivity of web site (IOW), ease of web navigation (EWN), and download speed of web site (DSOW).
Findings
The study results reveal that every online service category has a different set of crucial WIUFs. SIUs' web usability preferences were compared with those of general internet users.
Research limitations/implications
The participants were all Malaysians; therefore, generalising the findings to all SIUs will require a confirmatory study with SIUs from other parts of the world.
Practical implications
Web developers can use the results to design usable web sites for specific online service categories.
Originality/value
The research offers a simpler alternative to measure web usability and to determine which WIUFs are crucial for a specific online service category with consideration of the users' role. This study overcomes some weaknesses of previous studies, i.e. small sample size, no consideration of product‐task relationship, no specific customer group and cumbersome procedures.
Details
Keywords
Alloy 42 and, similarly, Kovar were developed to provide metallic feed‐throughs from the interior of ceramic components to the exterior. The low coefficient of thermal expansion…
Abstract
Alloy 42 and, similarly, Kovar were developed to provide metallic feed‐throughs from the interior of ceramic components to the exterior. The low coefficient of thermal expansion (CTE) of ceramic needs to be almost matched by the feed‐through metal to allow reliable hermetically sealed connections. For this purpose these alloys have served very well. However, because of its wide‐spread use for military applications, for which component hermeticity has been required, as well as because of the easier attachment of low‐CTE die to low‐CTE lead frames, Alloy 42 has found its way into plastic components with often disastrous results. When surface mount solder joints connect materials with different CTEs, global thermal expansion mismatches result. Also, if the materials to which the solder bonds have CTEs that differ from the CTE of solder, local thermal expansion mismatches result. These thermal expansion mismatches are the cause of most SM solder joint failures. Alloy 42 and Kovar not only cause significant global and local thermal expansion mismatches, but are inherently more difficult to solder because of the low solubility of nickel and iron, the main constituents of these alloys, in tin. Pull tests of solder joints show that under the best of circumstances a solder joint that includes an Alloy 42 or Kovar surface is only half as strong as one made to copper surfaces.
Martina G. Gallarza, Teresa Fayos, Rosa Currás, David Servera and Francisco Arteaga
Since universities adopted a “Student as Customer” approach, student consumer behavior is a field of study which has become crucial. In the European higher education area, more…
Abstract
Purpose
Since universities adopted a “Student as Customer” approach, student consumer behavior is a field of study which has become crucial. In the European higher education area, more understanding is needed on International students, and more precisely on Erasmus students. The purpose of this paper is to validate a multidimensional scale to assess Erasmus students’ value expectations (i.e. expected value) on the basis of costs and benefits in their choices as consumers of an academic experience abroad.
Design/methodology/approach
A survey conducted on a sample of 192 students from 50 universities show the role of functional, social and emotional values along with costs of time and effort in the perceived value of an Erasmus experience.
Findings
After validating the five scales, the results show that social and emotional are the aspects were students’ expected value dimensions are the highest, as the Erasmus experience is expected to enrich their studies and enable them to boost their self-confidence, while functionally helping them to find a job in the future. Concerning the sacrifices, the Erasmus experience has a high cost with regard to effort, time and energy, but students are willing to go through it: an Erasmus stay is seen as a good investment, whose benefits will be reaped in the long run.
Originality/value
The contribution of this paper comes from the scope and the target: a multidimensional trade-off approach to the expected value of the Erasmus experience. Other works have already depicted the educational experience through the value concept, but none, to the best of the authors’ knowledge, has measured expected value on the pre-purchase phase for Erasmus students.
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Keywords
Suzanne Amaro, Cristina Barroco and Joaquim Antunes
This study aims to apply the concept of brand love to a destination and investigate its antecedents and consequences. It also explores the moderating effects of time elapsed since…
Abstract
Purpose
This study aims to apply the concept of brand love to a destination and investigate its antecedents and consequences. It also explores the moderating effects of time elapsed since the establishment of the destination brand love relationship on the outcomes of destination brand love.
Design/methodology/approach
A total of 5,511 valid responses were obtained from an online survey distributed among former international students from the Erasmus program of the European Union. Partial least squares structural equation modeling was conducted to assess the hypotheses.
Findings
Destination brand love was found to have a significant impact on electronic word of mouth (eWOM), WOM, WOM intensity, recommendation and revisit intention. Moderation analysis revealed that the amount of time elapsed since the establishment of the destination brand love relationship did not affect these outcomes. Moreover, destination image and the Erasmus experience had a positive effect on destination brand love.
Practical implications
Destination marketers should focus on enhancing the Erasmus experience and on improving destination image perception, as these factors help develop destination brand love. Marketers should also be aware that this relationship has long-lasting effects.
Originality/value
This study adds to the sparse literature on brand love in relation to a destination. This gives the first results for the importance of Erasmus students to the promotion of a host country. It also contributes to the question of how long the brand love relationship can last.
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Keywords
Jeroen Huisman, Anneke Luijten-Lub and Marijk van der Wende
This chapter tries to explain the impact of the European Commission's ERASMUS programme on national higher education policies of 18 European countries. Based on an analysis of the…
Abstract
This chapter tries to explain the impact of the European Commission's ERASMUS programme on national higher education policies of 18 European countries. Based on an analysis of the literature on Europeanisation and policy impact, it is hypothesised that the impact will be very modest, but that there may be indirect impacts and differences in impact across countries dependent on institutional features of the higher education system. The empirical findings support the hypothesis: ERASMUS certainly has increased policy-makers’ awareness of the importance and possible consequences of further internationalisation. Nevertheless, ERASMUS has a more profound effect on higher education institutions and students. In addition, policy-makers have been much more influenced regarding their internationalisation policies by the Sorbonne and Bologna Declarations. There are some noteworthy differences between the countries that relate to specific domestic characteristics (e.g. language and colonial history).