bluuebunny/crossref_metadata_2025 huggingface dataset:
Facilitating Active Citizenship in Students Through the Strengthening of University-Community Partnerships
Authors: Swanzen Rika , Graham Victoria L.
Published: December 2018

In South Africa, the integration of community engagement into research and teaching roles is mandated through policy guidelines, which created the need for transformation of Higher Education (HE) since the late 1990s. One approach that allows such integration is service-learning and this approach is the focus of a research study conducted with field supervisors to determine the level of reciprocal engagement experienced by them. Communication plays a strong role in authentic university-community partnerships (UCPs) and Monash South Africa is cognisant of the challenges encountered with regard to diversity during placements or internships, some of which were discovered through the study. The ultimate aim of the chapter is to offer some recommendations for having a student-engaged and community-focused curriculum with reflections on its internationality and inter-disciplinary impact.
Political Messaging in Digital Spaces
Authors: Sandoval-Almazan Rodrigo
Published: December 2018

Political messaging is adapting to new digital spaces. However, the power of citizens through the use of this digital spaces is still unknown. Many citizens criticize political candidates using Facebook or Twitter, others build networks in Snapchat and some others try to collaborate with candidates using Periscope or WhatsApp. This research is focused in understanding this adaptation of political message on this platforms, analyzing the case of the presidential candidate Enrique Peña Nieto (PRI) in Mexico who won the presidency with a large participation but without the support of Twitter users. After two online protests against this presidential candidate - #IamnotProletariat and #Iam132 – political image could have been undermined and voters could have thought differently. But this was not the case and despite of this, the candidate won. The challenge to understand this online protest and its link to the political message is addressed in this paper.
How Civic Is Russia's New Civil Religion and How Religious Is the Church?
Authors: Teper Yuri
Published: December 2018

This chapter demonstrates how and why a shift in the balance between civic and religious elements of a civil religion can take place, using Russia as an illuminating case study. Post-Soviet Russia is used to demonstrate how religion can be utilized to reinforce national identity and the legitimacy of the political system in the face of their civic weaknesses. The chapter demonstrates how, eventually, the civic-democratic political model officially designated during Yeltsin's presidency gradually changed to a more religiously grounded one, albeit a model that is not fully recognized, during Putin's rule. Moreover, the Russian case allows us to differentiate between two possible levels of civil religion: an official and openly communicated secularism, and an established church religion, promoted by the establishment in more subtle but not necessarily less aggressive ways. It further shows that just as the state has to adopt religious features in order to be deified, religious institutions have themselves to become more secular to be suitable for adoption as the state's civil religion.
Smart City Governance
Authors: Bernardo Maria do Rosário Matos
Published: December 2018

Smart governance is one of the characteristics of smart cities, having its roots in e-government, in the principles of good governance, and in the assumptions of citizens' participation and involvement in public decision-making. This chapter aims to answer the question: “What smart governance practices are being implemented in smart cities” through an extensive literature review in the areas of e-government, good governance, smart cities and smart governance, and content analysis of the websites of seven smart cities: Amsterdam, Barcelona, Copenhagen, Lisbon, Manchester, Singapore, and Stockholm. The objective was to identify the presence of factors related with e-participation; e-services; and public administration functioning on the cities' websites. The chapter ends with directions for future research and the conclusion that all the smart cities analyzed presented some factors related with smart governance, but with different levels of development and application.
Designing a PhD Proposal in Quantitative Research
Authors: Islam Md. Ashraful
Published: December 2018

Research is only as good as one's proposal. It is found to be a more challenging job to guide for preparing research proposal than general project proposal and sometimes less formal as well. Some even argue that to implement the quantitative research accordingly, sufficient details should warrant a good research proposal. This chapter is aimed to propose a simple guideline for writing a research proposal designing in a quantitative research. In addition, it will help professional or academic researchers to develop good scientific research proposals for quantitative research design.
Negotiation With Gender Norms and Relations at the Workplace
Authors: Shill Shamali
Published: December 2018

This is a research proposal of a PhD study under the Department of Gender Studies, Faculty of Arts and Social Sciences, University of Malaya, Malaysia. In broader perspective, the proposal covers the issue of women's empowerment through the rapid employment of poor women in the ready-made garment industries in Bangladesh. The proposal has been written as the requirement for the PhD students at the University of Malaya. The writing contains fundamental components of a research proposal: study background, problem statement, research objectives, significance of the research, literature review on concepts and theoretical framework, research methodology, and a gantt chart showing the research's time schedule. The study will follow a qualitative research method including in-depth interview, focus group discussion, and factory visit as data collection tools. This chapter will be a useful guideline to the students and researchers who are interested in qualitative research approach in this particular field.
Design for a Closed-Loop Supply Chain System With Sensor-Embedded Refrigerators
Authors: Dulman Mehmet Talha , Gupta Surendra M.
Published: December 2018

This chapter presents a methodology to evaluate the benefit of using sensors in closed-loop supply chains. Sensors can be embedded into products to collect helpful information during their use and end-of-life (EOL) phases. This information can subsequently be employed to estimate the remaining lives of components and products and to ensure that proper maintenance is provided to avoid premature failures. The information is also useful in determining the quality of the components and products when planning EOL operations such as disassembly, inspection, and remanufacturing. To statistically illustrate these benefits, discrete event simulation is employed to a case study consisting of regular and sensor-embedded refrigerator systems. A design of experiments study is then employed where experiments are run to compare the two systems. The results reveal that the sensor-embedded systems perform much better than the regular systems in terms of disassembly costs, inspection costs, and EOL profits generated by selling the remanufactured products and components.
Influence of the EU Circular Economy Action Plan on Turkey's Energy Policy and Investments in Renewables
Authors: Okay Esin
Published: December 2018

The European Union Circular Economy Action Plan is a new enactment but rapidly growing to transform EU economies into more sustainable sources and surroundings adopting measures that include renewable energy investments and low carbon strategy. As the world still faces huge environmental changes and climate problems, energy remains the major issue for both economic and ecological sustainability. Low carbon energy strategy is the main target for EU circular economy enforcing renewable energy sources which are healthy, clean, and cheap. In this chapter, circular energy act and its development in Turkey are explored and questioned. The study emphasizes the great potential of renewables in Turkey and shows that there is still much to be done to transform the energy market in order to adopt circular economy in the future. Barriers of economic risks and lack of cultural awareness strongly challenge the progress of Turkey in energy solutions. And more than that, those problems trigger the financial concerns limiting the future energy projects.
Emotional Factors for Teleaudiology
Authors: Sterling Leon , Burrows Rachel , Barnet Belinda , Taffe Simone , McDonald Rachael
Published: December 2018

The internet has created new possibilities for health practitioners to deliver services remotely. The potential for telemedicine is yet to be fully realized. Many factors hamper the uptake of telemedicine, including funding models and the availability of technology. This chapter concerns one important area often neglected by technology developers: considering the emotions of users interacting with systems and services. The authors believe that consideration of emotions is essential for the advocacy, adoption, and appropriation of telemedicine services by a wide range of stakeholders, who have diverse abilities and motivations. They consider one area of telemedicine: teleaudiology. The authors outline emotional factors that need to be considered in providing teleaudiology services drawing on research from software engineering developing agent-oriented models of socio-technical systems, as well as knowledge of assistive technology frameworks. They consider how emotional factors can be taken into consideration with respect to a specific teleaudiology service provided by a successful company.
Quality and shell integrity of Japanese quail eggs: an assessment during storage and at market
Authors: Renukadevi B. , Himali H. M. C. , Silva G. L. L. P.
Published: December 2018

Rearing of Japanese quail (Coturnix coturnix japonica) has created an emerging interest in recent years among the small-scale poultry farmers in Sri Lanka, and is becoming a commercial venture in the alternative poultry industry. Thus, assessment was done on quality variation of Japanese quail eggs during the storage with different methods of packaging at room temperature. In the first experiment, a total of 120 eggs from the same flock were stored using three methods, i.e. with paper boxes filled with paddy husks, plastic egg cartons and without package at the room temperature. The egg quality during storage was assessed using egg weight, shell thickness, shape index, yolk colour, yolk index, Haugh unit and egg weight loss at weekly intervals in a complete randomize design with three replicates. In the second experiment, one hundred Japanese quail eggs collected from five market outlets were used to evaluate the shell integrity. The results were analyzed using Analysis of Variance and descriptive statistics in the two experiments. The results revealed that the egg weight, yolk colour, yolk index and Haugh unit were significantly decreased (P<0.05) with the storage period except shell thickness and shape index. The weight loss was increased significantly (P<0.05) during the storage irrespective of the method of packaging. However, packaging significantly reduced (P<0.05) the weight loss where plastic cartons recorded the eggs with the lowest weight loss. Changes of Haugh units and yolk index plateaued towards the end of storage irrespective of the method of storage among which no significant differences were observed (P>0.05). There was a significant (P<0.05) deterioration of yolk colour after two weeks of storage in all storage methods. Plastic carton preserved high yolk colour up to week-1, and showed no difference among the methods of storage towards the end of three weeks of storage. The results of shell integrity assessment revealed that only 66% of eggs were with total integrity and the rest were with failures during the market chain. The study concludes that quail eggs stored in paper boxes or plastic cartons could preserve the quality parameters, i.e. minimum quality losses, at room temperature compared to those stored without package. Commercial operations need to pay attention to improve the shell integrity of quail eggs in market chain.
Analysis of diversity and determination of duplicates among twenty one Dioscorea accessions through morphological and molecular characterization
Authors: Abeywickrama K. G. T. A. K. , Samarasinghe W. L. G. , Sumanasinghe V. A. , Edirisinghe E. S. C.
Published: December 2018

Several accessions of Dioscorea, a tuber crop of the family Dioscoreaceae, have been conserved under field and in-vitro conditions at the Plant Genetic Resources Center, Sri Lanka. Therefore, identification of duplicates in the collection is necessary as they cause a considerable wastage of input during the conservation process and leads to confusion when using these accessions in plant variety improvement programs. In this study, 21 Dioscorea accessions belonging to Dioscorea alata, D. esculenta, D. bulbifera and D. pentaphylla were characterized by 75 morphological characters and 15 simple sequence repeat (SSR) markers. The morphological characters were distributed as; 31 leaf, 21 stem, five flower and 18 tuber characters. The dendrogram showed that there are four main clusters without duplication. Accession 107 recorded as D. pentaphylla was well separated from other accessions while four accessions (21, 36, 113 and 92) were clustered into non-related clusters with their species. The SSR analysis was conducted on 20 Dioscorea accessions (except for the accession 107) through Power Marker. Polymorphism was detected among all Dioscorea accessions with 2 to 5 alleles per marker and a genetic distance ranging from 0.1333 (among accessions 101, 102, 103 and 109) to 0.7529 (between accessions 83 and 133). The phenogram resulted in three major clusters, which is almost in agreement with the existing classification. A disagreement was observed with respect to the accession 36 recorded as D. alata and 127 recorded as D. bulbifera as both were clustering with D. esculenta. Duplicates, accession 113 and 101, were classified with D. bulbifera and accession 62, 26 were identified with D. esculenta, respectively.
BCL6-Mediated Silencing of PD-1 Ligands in Germinal Center B Cells Maintains Follicular T Cell Population
Authors: Peng Cheng , Hu Qianwen , Yang Fang , Zhang Heng , Li Fubin , Huang Chuanxin
Published: December 2018

The programmed cell death protein 1 (PD-1) ligands PD-L1 and PD-L2 on germinal center (GC) B cells deliver coinhibitory signals to follicular T cells. The PD-L1/L2–PD-1 axis modulates the quality and quantity of follicular T cells and has been shown to influence the GC responses. However, the transcriptional control of PD-1 ligands on GC B cells remains largely unknown. In this study, we report that the transcription factor BCL6 is a key negative regulator of the PD-1 ligands PD-L1 and PD-L2 in GC B cells. Acute deletion of Bcl6 in mature GC B cells resulted in marked upregulation of mRNA and protein abundance of PD-1 ligands. Moreover, the expression levels of BCL6 and PD-1 ligands were inversely correlated during GC B cell development and in human GC–derived lymphoma specimens. Mechanically, BCL6 directly bound to the promoter region of PD-L1 and intron 2 of PD-L2 to suppress their transcription. In addition, BCL6 indirectly inhibited the transcription of PD-1 ligands by repressing the expression of STAT1/STAT3 and IRF1. Moreover, BCL6 exerted these effects via its BTB domain. Finally, PD-1 blockade promoted cell survival to sustain the follicular T cell pool in the presence of Bcl6-deficinet GC B cells. In summary, B cell–specific expression of BCL6 dampens the PD-L1/L2–PD-1 signaling to maintain the size of follicular T cells during GC development.
SRC3 Is a Cofactor for RORγt in Th17 Differentiation but Not Thymocyte Development
Authors: He Zhiheng , Zhang Jing , Du Qian , Xu Jianming , Gwack Yousang , Sun Zuoming
Published: December 2018

SRC3, a highly conserved member of the steroid receptor coactivator (SRC) family, is recruited by transcription factors to regulate cellular function. Previously, we demonstrated that SRC1, another highly conserved member of the SRC family, interacts with RORγt to regulate Th17 differentiation. However, the relationship between SRC1 and SRC3 in the regulation of Th17 cell function remains unknown. In this study, we demonstrate that mouse SRC3 interacts with RORγt in Th17 cells but not in thymocytes. In addition, Src3−/− mice exhibited defective Th17 differentiation and induction of experimental autoimmune encephalomyelitis but normal thymocyte development. Furthermore, a K313 to arginine mutation of RORγt (RORγt-K313R), which disrupts the interaction of RORγt with SRC3 but not with SRC1, impairs Th17 differentiation but not thymocyte development. These data suggest that SRC3 works with SRC1 to regulate RORγt-dependent Th17 differentiation but is not essential for RORγt-dependent thymocyte development.
PSMB11 Orchestrates the Development of CD4 and CD8 Thymocytes via Regulation of Gene Expression in Cortical Thymic Epithelial Cells
Authors: Apavaloaei Anca , Brochu Sylvie , Dong Mengqi , Rouette Alexandre , Hardy Marie-Pierre , Villafano Geno , Murata Shigeo , Melichar Heather J. , Perreault Claude
Published: December 2018

T cell development depends on sequential interactions of thymocytes with cortical thymic epithelial cells (cTECs) and medullary thymic epithelial cells. PSMB11 is a catalytic proteasomal subunit present exclusively in cTECs. Because proteasomes regulate transcriptional activity, we asked whether PSMB11 might affect gene expression in cTECs. We report that PSMB11 regulates the expression of 850 cTEC genes that modulate lymphostromal interactions primarily via the WNT signaling pathway. cTECs from Psmb11−/− mice 1) acquire features of medullary thymic epithelial cells and 2) retain CD8 thymocytes in the thymic cortex, thereby impairing phase 2 of positive selection, 3) perturbing CD8 T cell development, and 4) causing dramatic oxidative stress leading to apoptosis of CD8 thymocytes. Deletion of Psmb11 also causes major oxidative stress in CD4 thymocytes. However, CD4 thymocytes do not undergo apoptosis because, unlike CD8 thymocytes, they upregulate expression of chaperones and inhibitors of apoptosis. We conclude that PSMB11 has pervasive effects on both CD4 and CD8 thymocytes via regulation of gene expression in cTECs.
Upscaling panel size for Cu plating on FOPLP (Fan Out Panel Level Packaging) applications to reduce manufacturing cost
Authors: Hübner Henning , Ohde Christian , Ruess Dirk
Published: December 2018

Electrolytic metal deposition is a key process step in the manufacturing of vertical and horizontal interconnections used in today's PCBs and IC substrates on one hand and advanced packaging applications on the other hand. Historically both application areas were clearly defined and separated by different requirements in feature sizes and substrate formats. PCBs and IC substrates were based on organic large scale substrates with rather large features while advanced packaging technology is wafer based with the capability to incorporate fine features down to a few microns.

The ever increasing demand of higher performance, lower cost and thinner end user devices like smartphones require intense developments and innovation in all areas of the electronic component design including the substrate and chip packaging. Latest manufacturing technologies in both areas like fan-out wafer level packaging and advanced substrates are constantly emerging and promise to be a critical piece to meet these requirements. As a consequence both areas are currently merging while creating a new application segment. This segment combines the request of small feature sizes with the manufacturability on large scale substrates. Obviously many of the traditional process technologies like plating and available equipment cannot be easily adopted and need certain developments, adaptions and improvements.

In this respect, a key challenge in the area of electrolytic metal deposition is the combination of various challenging requirements: creation of feature sizes down to 2μm L/S with heterogeneous feature density on large substrates up to 600mm at excellent metal thickness uniformity and high plating speed. The paper presents latest studies and conclusions in critical performance areas of the plating process such as electrolyte fluid dynamics, impact of anode design, pulse reverse rectification and newly designed electrolytes. Finally latest test results of optimized process conditions will be discussed in detail with different feature sizes providing data of within die and within substrate uniformity. All tests are done on panel level, both organic and glass substrates.

The latest findings and achievements of the discussed panel based plating process technology will support the industry to develop panel based packaging processes that meet both technical and commercial requirements.
Converter-Level Integration for Wide Band-Gap Automotive Power Electronics
Authors: Johnson C Mark , Espina Jordi , Ahmadi Behzad , Dai Jingru , Mouawad Bassem , Empringham Lee , De Lillo Liliana , Dimarino Christina
Published: December 2018

Wide band-gap (WBG) semiconductors offer many potential benefits to designers of power electronic systems. Lower switching losses allow operation at higher switching frequencies, which in principle allows a reduction in passive component values in many converter applications. However, efficient operation at higher switching frequencies requires increased voltage and current transition rates. With conventional packaging and circuit construction, parasitic inductance and capacitance can deteriorate converter performance, reducing efficiency and adding to the electromagnetic interference (EMI) emitted from the system. Outside the commutation cell, fast voltage transitions may lead to unacceptably high levels of conducted and radiated EMI, so approaches involving the local filtering of converter outputs are attractive. To mitigate these effects in conventional modules, switching speeds are often deliberately limited and the potential benefits of using WBG technologies cannot be fully realized. Here we examine the design and realization of Converter-in-Package (CiP) modular blocks for system power levels from 100s W to 100s kW, incorporating individual commutation cells with close-coupled gate drives, input/output filtering and reduced EMI. The concept is illustrated through the realization of a modular, segmented power converter for an integrated drive.
Enabling a Robust Copper Seed Etch Process for Fine Line RDL by Electroplating on a Thin PVD Seed Layer
Authors: Bernt Marvin , Van Valkenburg Paul , Surdock David , Lianto Prayudi
Published: December 2018

Integration of heterogeneous chips into fanout packages requires interconnection by redistribution lines (RDL). As I/O counts increase, higher density routing is required, and can be achieved by finer RDL line/space dimension, stacking multiple RDL layers, or both. Conventional WLP plating processes for pillar or RDL use a PVD deposited copper seed layer between 1000 and 4000Å thick. Removal of this copper seed layer by isotropic wet etching leads to sidewall loss that can be ignored on larger features, but can lead to significant copper cross sectional area loss on features with 2/2μm line/space and below. By enabling plating onto much thinner seed layers, next generation WLP plating chambers enable a conventional copper seed layer etch process with less sidewall loss and more uniform cross-sectional area across plated features.
Fabrication of an advanced epoxy based molding compound with high thermal conductivity and outstanding mechanical properties
Authors: Dadvand Nazila , Dadvand Mina , Kipouros Georges
Published: December 2018

A novel molding compound was fabricated through surface modification of aluminum particles followed by chemical grafting to an epoxy based resin. The fabricated material demonstrated high thermal conductivity and outstanding mechanical properties. A thin layer of alumina was formed on the surface of aluminum particles (spherical with average 30 μm in diameter) by ultrasonic treatment with hydrogen peroxide followed by functionalization with a hydroxylated long-chain organic acid. The fabricated composite was chemically bonded to epoxy skeleton. The chemical bond formation between the filler and organic matrix was responsible for high thermal conductivity as well as outstanding mechanical properties. As well, the loading capacity of epoxy matrix to surface modified fillers was remarkably higher than non-modified fillers.
Reliability of an Electronic Product Fabricated of Mass-Produced Components
Authors: Suhir E.
Published: December 2018

Bathtub curve (BTC), the reliability “passport” of an electronic product, is affected by two major irreversible processes: the decreasing with time statistics-related failure rate (SFR) process and increasing with time physics-of-failure-related failure rate (PFR) process. The first process dominates at the infant-mortality portion (IMP) of the curve and the second one – at its wear-out portion (WOP). For many electronic products these two processes compensate for each other at the BTC's steady-state portion. The SFR process can be predicted theoretically for products comprised of mass-produced components, i.e., for typical electronic products. This could be done assuming that the failure rates of the components received by an electronic product manufacturer from various and numerous vendors can be viewed as random variables distributed between zero and infinity and that the SFR and PFR processes are statistically independent. The predicted non-random SFR depends, of course, on the particular probability distribution function (PDF) of the random SFRs of its components. Two PDFs for the components' random SFR have been considered in this analysis: normal (Gaussian) and Rayleigh. The normal law turned out to be more conservative: it led to a slower decrease in the SFR of the product than the Rayleigh law. Future work should include the investigation into the most realistic distributions of the random SFR for the most critical and the most vulnerable components obtained from major vendors of the particular manufacturer, particular products and applications. The computed data indicate that the decrease in the resulting failure rate at the WOP of the BTC because of the favorable effect of the decrease of the non-random SFR with time can be appreciable for highly reliable products expected to function for a long time.
Warpage Behaviors of System-in-Packages on a Substrate Strip
Authors: Ouyang Eric , Ahn Billy , Gu SeonMo , Hsu Jim , Jeong Yonghyuk , Kim JaeMyong , Lin Susan , Liu Goran , Yang Anthony
Published: December 2018

In this paper, the impact of two different types of warpage, strip warpage and system-in-packages (SiP) module warpage, are considered and studied, both experimentally and numerically. An advanced material characterization method is also conducted to study the curing reaction and Pressure-Volume-Temperature-Cure (PVTC) kinetics of the packages. The curing reaction of epoxy resins, as a function of temperature and activation energies, is experimentally determined. During the curing process, the viscosity of epoxy resins change with temperature and conversion rate. The Castro-Macosko model is adopted to describe the rheological properties of epoxy resins. Experimentally, we have prepared substrate strip samples with different component density and molding compound materials. Each substrate strip contains eighteen system-in-packages. The warpages of all substrate strips and all the system-in-package modules were measured, compared, and correlated.
Mixed-Port Hybrid Parameters for High-Speed Differential Lines
Authors: Engin A. Ege , Ndip Ivan , Lang Klaus-Dieter , Aguirre Jerry
Published: December 2018

High-speed transmission lines are commonly routed as differential lines to control sensitivity to noise on the reference planes at higher speeds. The preferred method of characterization of differential lines is in terms of mixed-mode scattering parameters, as they provide insight into the behavior of differential and common signals, as well as the mode conversion among them. These mixed-mode scattering parameters can be mathematically obtained from single-ended parameters, which can for example be measured with a 4-port vector network analyzer. There has been recent concerns about the so-obtained mixed-mode scattering parameters, especially for tightly-coupled lines, resulting in extended or modified definitions of mixed-mode scattering parameters. This can be a point of confusion in interpreting the behavior of differential lines. In this paper we introduce the mixed-port hybrid parameters, which do not suffer from any such ambiguous definitions, as they are based on intuitive differential and common-port excitations of the network. As such, mixed-port hybrid parameters can be used to analyze the mixed-mode performance of any arbitrary 4-port network, certainly including coupled or asymmetrical lines, without any ambiguity.
BATCH MICROWAVE PLASMA CLEANING FOR ROBUSTNESS ENHANCEMENT OF AUTOMOTIVE DEVICES: AN ALTERNATIVE TO STRIP-TYPE RADIOFREQUENCY PLASMA
Authors: Abarro Ghizelle Jane E. , Delos Santos Rod J. , Denoyo Alvin B. , De Lazo Darwin , Ramos Manny S.
Published: December 2018

This study attempts to explore Batch-type Microwave (B-MW) plasma cleaning as a potential alternative to the conventional Strip-type Radiofrequency (S-RF) plasma; for application prior molding to improve adhesion along the mold-lead frame interface. Performance of B-MW was evaluated in terms of improvement in surface wettability, quantified via Contact Angle (CA) measurements. Mix of typical industrial plasma gases (Ar, H2 and O2) were assessed. Constant flow pattern was observed to significantly improve surface wettability and uniformity compared to its pulsed counterpart; and also affect the effect of other factors on the over-all cleaning performance of B-MW. Proceeding with constant flow pattern, surface wetting was found to improve with increasing power and cleaning time. The combination of O2 and H2 plasma was found to be more effective compared to utilizing them separately. Both cleaning time and flow rate increased the amount of reactive species that come in contact with the contaminants. With optimized parameters, B-MW was confirmed to be a more effective plasma method than S-RF i.e. 12% more effective in removing contamination and improving surface wettability, up to 20% better uniformity and can boost throughput to at least 34%.
New Photosensitive Dielectric Material for High-Density RDL with Ultra-Small Photo-Vias and High Reliability
Authors: Okamoto Daichi , Shibasaki Yoko , Shibata Daisuke , Hanada Tadahiko
Published: December 2018

This paper presents an advanced ultra-thin photosensitive dielectric Film (PDM) newly developed with high resolution, low CTE and low residual stress for next-generation high-density redistribution layer (RDL), 2.5D interposer, and high-density fan-out package applications. For high-density RDL, photosensitive dielectric materials need to have low CTE to achieve high package reliability. The CTE of the material is 30–35ppm/K. While maintaining the low CTE, we successfully demonstrated the minimum micro-via diameter of 3um in the 5um thickness. Curing temperature of the PDM is 180°C × 60 min. which is lower than most of the advanced dielectric materials which currently used in industry. Low-temperature curing process results in low stress. We have calculated residual stress in the cured PDM from a test result of warpage measurement on 4 inch wafer. As another benefit of the PDM material in curing process, the PDM can be cured in air oven. Most of advanced photo dielectric materials need to cure in N2 oven due to prevent an oxidation of the material. We have demonstrated copper traces of 2um lines and spaced on the PDM by using semi-additive process (SAP) with sputtered Ti/Cu seed layer. Thanks to the low CTE and low residual stress due to the low-temperature curing, it passed temperature cycle test (1,000 cycles) with daisy chain structure which has 400 vias in the structure. It can be concluded that the newly developed PDM is a promising dielectric material for highly reliable high-density redistribution layer (RDL) for 2.5D interposers and fan-out wafer level package applications.
Photosensitive Polyimide having low loss tangent for RF application
Authors: Tomikawa Masao , Araki Hitoshi , Kiuchi Yohei , Shimada Akira
Published: December 2018

Progress of 5G telecommunication and mm radar for autopilot, high frequency operation is required. Insulator materials having low loss at high frequency is desired for the applications. We designed the low dielectric constant, and low dielectric loss materials examined molecular structure of the polyimide and found that permittivity 2.6 at 20GHz, dielectric loss 0.002. Furthermore, in consideration of mechanical properties such as the toughness and adhesion to copper from a point of practical use. Dielectric properties largely turned worse when giving photosensitivity. To overcome the poor dielectric properties, we designed the photosensitive system. After all, we successfully obtained 3.5 of dielectric constant and 0.004 of dielectric loss, and 100% of elongation at break. In addition, we offered a B stage sheet as well as varnish. These materials are applicable to re-distribution layer of FO-WLP, Interposer and other RF applications for microelectronics.
Novel Low Temperature Curable Photo-Patternable Polyamide with High Planarity for Wafer Level Fan-Out Packaging (WLFO)
Authors: Nawrocki Daniel , Cooper Andrew , Koizumi Takanori , Inagaki Shinya , Kawamoto Naoki , Honda Nao , Markt Kristina , Bernal Milton
Published: December 2018

As Wafer Level Fan-Out Packaging (WLFO) designs continue to evolve, higher pattern densities for Cu lines and interconnects continue to increase while thickness continues to decrease. As Cu densities increase, the patterning resolution of the RDL dielectric needs to shrink to allow increased bump density. The higher Cu density in turn requires enhanced dielectric performance to minimize Cu migration, whilst utilizing lower temperature and shorter cure times which result in lower levels of wafer warpage.

Minimizing mechanical stress, continues to be a critical function of the RDL dielectric. Warpage leads to poor yields, distorting the planarity of the package and ultimately leading to stress induced failure from cracking and delamination. Reduction of the thermal budget is the primary means of reducing mechanical stress in WLFO designs. The amount of Cu in the package continues to increase. Differences in thermal expansions of such and the dielectric increase with temperature. Further, conventional solder reflow processes and set points will continue to be used, therefore the RDL dielectric must continue to be thermally and mechanically stable but capable of being cured at lower temperatures, 180–200 °C to minimize overall mechanical stresses from thermal expansion.

We present a novel polyamide based RDL dielectric, KMRD, designed to achieve current and future WLFO design requirements. KMRD is a low temperature curable, aqueous (2.38%TMAH) developable dielectric capable of meeting industry standards for mechanical and electrical requirements, with a high level of reliability while utilizing a single stage cure at 185 °C. KMRD provides clear advantages over incumbent materials, with low temperature cure, improved pattern resolution, wide process latitudes, superior adhesion, chemical compatibility, and cost benefits using standard processing equipment and chemistry.
A study of Sub-micron Fan-out Wafer Level Packaging solutions
Authors: GOTO Yoshio , URUSHIHARA Kosuke , TAKESHITA Bunsuke , MORI Ken-Ichiro
Published: December 2018

In Fan-out Wafer Level Packaging (FOWLP) processes, redistribution layer (RDL) line width reduction is a key challenge to expand the FOWLP market to multi-chip interconnections, including interconnections between SoC and DRAM, split-die connection of FPGA, and interconnections between image sensors and SoC. Next generation FOWLP requires 1.0 μm RDL and future FOWLP is targeting 0.8 μm RDL. To meet these requirements, Canon has developed new projection optics with a high NA and wide-field that is best suited for sub-micron FOWLP. These projection optics are a new option for FPA-5520iV steppers, offering NA 0.24 imaging and a 52 × 34 mm exposure field. FPA-5520iV steppers with NA 0.24 provide excellent 0.8 μm resolution performance throughout all imaging fields thanks to Canon's wave-front aberration based projection optics manufacturing methods and on-axis optical tilt focus sensor.
Flexible PET Substrate for High Definition Printing of Polymer Thick Film Conductive Pastes
Authors: Dobie Art
Published: December 2018

A major obstacle in screen printing conductive low temperature curing polymer thick film (PTF) pastes onto common flexible PET substrate materials is the substantial spread of the pastes beyond the designed line width after printing. Industry observation and controlled testing have shown this spread can be as much as 80% over the circuit design's intended line width. This phenomenon prevents designers from increasing circuit density and/or reducing circuit real estate without incorporating other, more involved and higher cost patterning methods. In many cases, flexible circuit fabricators, desiring more accurate high definition circuit elements, may have to subcontract parts out of house in order to incorporate alternate patterning methods. In-turn this subcontracting leads to a loss of control of both cost and lead time.

This paper will provide results of numerous in-house and field testing, comparing printed line width control, edge definition, and improved conductivity of printed polymer Ag conductors on different flexible PET substrates.
Wire Bonding Advances for Multi-Chip and System in Package Devices
Authors: Xu Hui , Shah Aashish , Milton Basil , Qin Ivy
Published: December 2018

Wire bonding continues to be the most commonly used interconnection technology due to its low cost, high yield rate, increased flexibility and improved reliability. Among wire bonded packages, the high growth areas include Multi-Chip modules and System in Package (SiP) applications. A type of wire bonding, Stand-Off-Stitch Bond (SSB), is widely used in Multi-chip, die-to-die, SiP and light-emitting diodes (LEDs).

The SSB process starts with a flat-topped bump bonding on the substrate or die, followed by the formation of a new ball bond (1st bond). The stitch bond (2nd bond) of that wire is bonded on top of the initial bump. This paper focuses on key SSB process steps, by examining the main challenges and solutions of SSB applications. We demonstrate ultra-fine pitch SSB process capability with 0.6 mil Au wire using newly developed response-based processes for sub-20 nm node wafer technology.
Investigation of a proactive glass filler removal in IC substrate build up films and its effect on topography and copper adhesion reliability
Authors: Kempa Stefan , Friz Wolfgang , Gaul Florian , Habig Ellen , Gregoriades Laurence J.
Published: December 2018

In order to achieve interconnections at extremely small scale, the latest build up laminates contain increasing amounts of spherical glass fillers, which are needed to compensate the CTE mismatch between the epoxy based resin matrix and the electroplated copper circuits. Desmear of the resin surface during industrial processing exposes these glass fillers and weakens their anchoring in the surrounding resin matrix, which decreases adhesion strength of the plated copper.

We describe a newly developed cleaner process for the removal of glass fillers in industrially important build-up materials. Its effects on cleanliness and copper to resin adhesion is described in detail and illustrated by SEM imaging. Finally we propose a mechanism, explaining the adhesion increase as compared to standard processing and fluoride etch treatment.
Smart and Connected Bioelectronics for Seamless Health Monitoring and Persistent Human-Machine Interfaces
Authors: Kim Yun-Soung , Yeo Woon-Hong
Published: December 2018

Recent advancement of flexible wearable electronics allows significant enhancement of portable, continuous health monitoring and persistent human-machine interfaces. Enabled by flexible electronic systems, smart and connected bioelectronics are accelerating the integration of innovative information science and engineering strategies, ultimately driving the rapid transformation of healthcare and medicine. Recent progress in development and engineering of soft materials has provided various opportunities to design different types of mechanically deformable systems towards smart and connected bioelectronics. Here, we summarize the key properties of soft materials and their characteristics in the context of wearable sensors and electronics. Details of functionality and sensitivity of the bioelectronics are discussed with applications in health, medicine, and machine interfaces. In addition, we introduce recent examples of bioelectronics that offer persistent human-machine interfaces to control prosthetic hands, wheelchairs, or computer interfaces.
Screen Printing Fine Pitch Stretchable Silver Inks onto a Flexible Substrate for Wearable Applications
Authors: Pan Jianbiao , Keif Malcolm , Ledgerwood Joshua , Rong Xiaoying , Wang Xuan
Published: December 2018

The lightweight and bendable features of printed flexible electronics are increasingly attractive. Currently stretchable silver inks are formulated for wide traces, typically larger than 2 mm. To attach ultra-thin silicon chips that have fine pitch onto printed organic substrate, it is necessary to print fine trace width/space that matches the pitch of the chips, which may be less than 200 microns.

This paper presents the development and optimization of the screen printing process for printing stretchable silver ink onto stretchable thermoplastic polyurethane (TPU) substrate. A test vehicle was designed including 50 μm/5 mm (line width/line length) to 350 μm/35 mm lines (at 4 biases). The stretchable ink selected was DuPont PE 873 and Dupont's PE 5025 ink (non-stretchable conductive flake silver) was used as a “control” to baseline the printing process. The substrate used was Bemis TPU ST604. The experiment was done on a DEK Horizon 03i printer. A DEK squeegee 200 (Blue) and a DEK 265 flood bar (200 mm) were used. A 2-level factorial design with three replicates was selected to investigate the effect of process parameters on the quality of prints. The quality of the prints is characterized by 1) resistance of traces, 2) sheet resistance, 3) z-axis height, and 4) trace width/spacing.

We observed significant noise in the z-axis printed silver ink height measured by profilometry and concluded z-axis height is not a good response variable for characterizing screen printing stretchable silver ink onto TPU substrate, mainly due to high roughness of the TPU substrate. We proposed calculated sheet resistance based on the measured resistance value, trace width, and trace length, which can replace trace height measurements on rough profile substrates.

We found that squeegee pressure and emulsion thickness have statistically significant effects on calculated sheet resistance of print traces while print speed does not have statistically significant effects. In our experiment setting levels, the lower the squeegee pressure, the lower the calculated sheet resistance that is achieved. The emulsion with higher emulsion over mesh (EOM) is better than the emulsion with lower EOM since it can achieve lower sheet resistance. After optimizing the screen printing process, we were able to print 100 μm (4 mils) trace width and spacing with high consistency.
Electrochemical capacitance based method applied to epoxy molded devices
Authors: Rolandi Paolo , Magagnin Luca , Valzasina Carlo , De Pascalis Daniele , Tocchio Alessandro , Garnier Audrey Betty Marie , Filoni Giuseppe , Pecchia Francesco
Published: December 2018

Sensors as devices can be considered the most advanced microelectronics systems built by connecting different types of microchips as micro-mechanical structure (MEMS) and Application Specific Integrated Circuit (ASIC). These Systems in Package (SiP) use mostly an epoxy resin material whose major reliability concern is the moisture absorption after humidity exposure so that the electrical interconnections between the dies become surrounded by a non-waterproof material. This article describes how the real resin morphology influences the electrical signals provided by a MEMS to an ASIC in an inertial sensor SiP. In particular, the study is focused on the pads area of the MEMS, where a large surface of polysilicon is in direct contact with the resin. As the epoxy structure close to the above regions may be affected by a non-homogeneous distribution of fillers, the compound humidity sensitivity may locally increase and the electrical properties may be conditioned in the same way. The goal of this study is to define a suitable method to quantify and characterize the local change of the resin properties after moisture absorption. After deeply analyzing the results of the standard electronics measurements methods an electrochemical approach has been selected as the best appropriate one to match the physical reality.
Evaluation of children with protein energy malnutrition and level of malaria parasitemia in Kwara State, Nigeria
Authors: Saka Aishat Oluwatoyin , Saka Mohammed Jamiu , Sa’adu Lateefat Olayinka
Published: December 2018

Malaria and Protein-Energy-Malnutrition (PEM) are two major causes of childhood mortality in sub-Saharan Africa. Malaria can predispose a child to PEM and the reverse may also be true. Recent studies have presented inconsistent findings about nutritional status and the occurrence of malaria among the children. The goal of this study was to evaluate the association between PEM and malaria parasitemia if any. A case control study in which 90 children diagnosed for PEM (aged 6-59 months), and another well-nourished 90 children age and sex-matched controls were evaluated for malaria parasitemia. A semi-structured proforma was used to obtain relevant information on the children’s sociodemographic characteristics, nutritional indices amongst others. Venous blood sample was collected and thick and thin blood film were prepared and viewed under the microscope. Malaria parasitemia was present in 82 (91.1%) of malnourished group and 12 (13.3%) of the well-nourished group (P<0.05 OR=66.62). Malaria parasitemia was highest in those with kwashiorkor and marasmic kwashiorkor compared with underweight. These differences were statistically significant (P<0.05). The study demonstrates that malnourished children have higher degree of malaria parasitemia and are at risk of malaria. It also shows that severe forms of malnutrition are associated with heavier malaria parasitemia. It is therefore recommended that all malnourished children should have access to use of Insecticide Treated Nets (ITN), malaria chemoprophylaxis as well as empiric treatment of malaria in endemic areas where access to malaria parasite diagnosis is difficult.