bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Silicon Wafer Bump Pad Structures on Solder and Cu Pillar Flip-Chip Reliability
Authors: Asoy Shirley , Exon Scott , Zhu Liping , Moon Peter , Carroll Michael , Pan Shannon 
Published: November 2016

Abstract
Solder and Cu pillar flip-chip silicon die technologies have been widely used in chip to package mobile module products. During the early design phase, integrated circuit (IC) designers usually apply standard bump design rules, due to lack of information on the reliability of the metal layer stack-up with different bumping processes. However, module reliability data has demonstrated that the stack-up and thickness of the metal layers in a silicon die has a great effect on package stresses, especially for large area Cu pillar flip chip die. In this paper, the effects of bump pad structures on solder and Cu pillar bump reliability have been investigated. A 3D mechanical stress model was developed to compare and optimize various bump structures. A test vehicle with die and module was designed and assembled in a volume production environment. Assembly in-line data was collected and analyzed, and is presented in this paper. Reliability testing and failure analysis were performed to verify the failure modes. Guidelines for designing solder and Cu Pillar Flip-chip bump pad structures have been developed, and are presented in this paper.
Comparative Modeling and Analysis of Lead-Free Solder Extrusion for the Design of Reliability
Authors: Lee Youngtak , Link Doug 
Published: November 2016

Abstract
Due to rapid growth of the microelectronics industry, packaged devices with small form factors, low costs, high power performance, and increased efficiency have become of high demand in the market. To realize the current market development trend, flip chip interconnection and System-in-Package (SiP) are some of the promising packaging solutions developed. However, a surprising amount of surface mount technology (SMT) defects are associated with the use of lead-free solder paste and methods by which the paste is applied. Two such defects are solder extrusion and tombstoning. Through the use of design of experiments (DOE), lead-free solder defect causes can be better understood and subsequently reduced or eliminated. This paper will examine the failure modes of solder extrusion and tombstoning that occurred when two different types of lead-free solders, Sn-Ag-Cu (SAC) and BiAgX were used within a SiP for attachment of surface mount devices (SMD) chip components. The systematic investigation will include the comprehensive failure analysis of the SMD components and compare the modeling and analysis of the two different solder types utilizing the design of experiments methods.
Reliability Analysis of Lead-Free Solder Joints with Solder Doping on Harsh Environment
Authors: Zhao Cong , Sanders Thomas , Hai Zhou , Shen Chaobo , Evans John L. 
Published: November 2016

Abstract
This paper investigates the effect of long term isothermal aging and thermal cycling on the reliability of lead-free solder mixes with different solder compositions, PCB surface finishes, and isothermal aging conditions. A variety of surface mount components are considered, including ball grid arrays (BGAs), quad flat no-lead packages (QFNs) and 2512 Surface Mount Resistors (SMRs). 12 lead-free solder pastes are tested; for BGA packages these are reflowed with lead-free solder spheres of SAC105, SAC305 and matched doped solder spheres (“matched” solder paste and sphere composition). Three surface finishes are tested: Organic Solderability Preservative (OSP), Immersion Silver (ImAg), and Electroless Nickel Immersion Gold (ENIG). All test components are subjected to isothermal aging at 125°C for 0 or 12 months, followed by accelerated thermal cycle testing from −40°C to 125°C. Data from the first 1500 cycles is presented here, with a focus on the effect of surface finish on package reliability. Current results demonstrate that the choice of surface finish has a strong effect on reliability. However, different solder materials appear to show different reliability trends with respect to the surface finishes, and the reliability trends of BGA and SMR packages also diverge.
How Mitigation Techniques Affect Reliability Results for BGAs
Authors: Caswell Greg , Keener (Black and Decker) Melissa 
Published: November 2016

Abstract
Since 2006 RoHS requirements have required lead free solders to take the place of tin-lead solders in electronics. The problem is that in some environments the lead free solders are less reliable than the older tin-lead solders. One of the ways to solve this problem is to corner stake, edge bond or underfill the components. When considering what mitigation technique and material to use, the operating conditions must be characterized. The temperature range is important when selecting a material to use since the glass transition temperature (Tg) and coefficient of thermal expansion (CTE) are important properties. If improperly chosen, the mitigation material can cause more failures than an unmitigated component.
This study focused on 208 I/O BGAs on a 4 layer FR4 board. There were three solders tested; two lead free (SAC305 and SN100C) and one leaded (SnPb). Three mitigation techniques were tested: corner staking, edge bonding, and underfilling. Each of these techniques had two mitigation materials tested. One material was reworkable and the other was not. The boards were subjected to mechanical shock testing and sinusoidal vibration testing until failure.
The results of the testing show that no one mitigation technique is best for all of the conditions tested. The same is true for the mitigation material. The best choice of mitigation technique and material is application dependent.
High Speed Serial Interfaces in 2.5D Integrated Systems
Authors: Chaudhary Muhammad Waqas , Heinig Andy 
Published: November 2016

Abstract
High speed communication has been a topic of great interest in the last decade due to excessively high data rates required between chips especially pushed by the measurement equipment industry to support extremely high bandwidth data sampling. Serial communication is chosen to support these data rates which are pushing further and further into higher data rate regimes. It is important to understand how the 2.5D integration of chips on the interposer can support serial communication and what the designer can do to leverage the special features of interposer channel to achieve lower power and higher speed. This paper will present the interposer complete channel full 3D Electromagnetic simulation based model extraction. It also presents the simulation of channel with real serial communication transmitter and receiver circuit models to describe the proposed interposer performance for multi Gb/s data rates. Also a comparison is shown for different settings of transmitter and receiver circuits under the interposer channel.
Process development and material characterization of Cu-Cu thermo-compression bonding (TCB) for high-conductivity electrical interconnects.
Authors: Bajwa Adeel , Marathe Niteesh , Jangam SivaChandra , Pal Saptadeep , Liu Ping-Yu , Goorsky Mark , Iyer Subramanian S. 
Published: November 2016

Abstract
In this work, we focus on metal-metal Thermo-Compression Bonding (TCB) for realizing assembly of dielets to a silicon interconnect fabric (IF). The popular metal choices include bare Cu, Cu plated with Au and Au. Our approach simplifies the metallurgies used in classic chip-to-package assemblies by avoiding the use of solder and the concomitant issues of intermetallic formation such as electrical resistance and brittleness. In this paper, we address TCB parameter optimization and material characteristics of these metal-metal TCB joints. The roles of two physical mechanisms on Cu-Cu interface voiding i.e. surface roughness prior to TCB, oxide presence at bonding interface are evaluated in detail.
Ultra-thin glasses for semiconductor packaging
Authors: Sprengard Ruediger , Jotz Matthias , Letz Martin , Parthier Lutz , Prince Fredrik , Woehrmann Markus , Thomas J.-U. , Toepper Michael 
Published: November 2016

AbstractGlasses are homogeneous, many glasses have excellent dielectric properties at GHz frequencies and some have thermal expansions (CTE) which are close to silicon. Ultrathin glasses (UTG) with thicknesses of 25 μm to 200 μm (0.001 to 0.0079 inch) offer numerous options for packaging, integration and co-processing in semiconductor manufacturing processes. We introduce SCHOTT UTG including paths to further improve their mechanical stability and strength. We use laser ablation in 50μm thick glass and show via fabrication with a potential of mass manufacturing with via diameters of 30μm, 38μm pitch and a position accuracy of +/− 1μm. The structures are metallized using sputtering and electroplating which leads to hermetic, tight conducting through glass-vias (TGV).
High Thermal Conductive Die Attach Paste Using Polymer and Micron Size Silver for Power Semiconductor Package
Authors: Jin Howard (Hwail) , Xu Kewei , Naungayan Loreto , Quinones Jose 
Published: November 2016

Abstract
Power semiconductor package manufactures and electronic device suppliers have been looking for Pb-free alternative to traditional high Pb solder die attach adhesives. Lead solders have high thermal conductivity, 30–50W/mK, and known process with some difficulties in high volume mass production such as void, bond line control, and requiring reducing atmosphere such as forming gas. Lead is now categorized as hazardous substance to human body and environment and its products are scheduled to be banned within a few years. Standard silver epoxy pastes and Electrically Conductive Adhesives (ECSs) are other forms of die attach adhesives but the thermal conductivity is not adequate for Power devices. Eutectic gold-tin solder (80Au20Sn) has 57W/mK but it is high cost material. Currently Silver sintering material has become popular for electronic device because it has high thermal conductivity (150~250W/mK) by using nano silver sintering. But it requires high bonding temperature and pressure. It makes brittle bonding structure and has limitation in die size due to high stress.
New silver sintering material in this paper is composed of micron size silver and organic polymer. This technology overcomes all the limitations of conventional silver epoxy, eutectic gold thin solder and silver sintering product by using the unique design of polymer composition. This new silver sintering technology using polymer and micron size silver is a cost effective solution to replace Pb solder for power device and the thermal performance is almost same as nano silver sintering products. The application process is the same as standard silver epoxy and does not require new equipment. It is a cost effective drop in solution.
Patellofemoral Joint Arthroplasty: Our Experience in Isolated Patellofemoral and Bicompartmental Arthritic Knees
Authors: Sabatini L. , Schirò M. , Atzori F. , Ferrero G. , Massè A. 
Published: November 2016

Introduction Isolated patellofemoral (PF) arthritis is rare, and there is no complete agreement about the best surgical treatment. The operative treatments are total knee arthroplasty and patellofemoral replacement (PFR). The incidence of many early complications of PF arthroplasty has decreased with the introduction of newer designs. Nowadays, the main cause of revision surgery is the progression of tibiofemoral osteoarthritis. In the past, PF arthroplasty was contraindicated in patients with evidence of osteoarthritis or pain in medial or lateral tibiofemoral compartments. The improvement in implant designs and surgical techniques has allowed the addition of a monocompartmental arthroplasty for the medial or lateral tibiofemoral compartment. In this work, we evaluate our first experience with PF arthroplasty and its combination with unicompartmental knee arthroplasty. Materials and Methods From May 2014 to March 2016, we treated 14 patients. An isolated PF arthroplasty was performed in six knees (five patients), and a combined PF and unicompartmental knee arthroplasty was performed in nine cases. We observed a significant improvement in the clinical and functional Knee Society Scores (KSSs) after surgery in our patients. Results We obtained good results in our cases both for clinical and functional KSSs. Patellar clunk was recorded in one case. Discussion and Conclusion We are going toward a new attitude in which partial osteoarthritic changes could be treated with partial resurfacing prosthetic solutions such as unicompartmental, bi–unicompartmental or PFR alone, or unicompartmental combined, which respects the cruciates and achieves maximal bone preservation, which is vital, particularly, for young patients.
Reconstrucción virtual 3D del coro del Convento de Santa Clara de Toro (Zamora): la recuperación de un ámbito medieval de devoción femenina mediante el registro fotogramétrico y técnicas de renderización
Authors: Gutiérrez Baños Fernando , Morillo Rodríguez Francisco M. , San José Alonso Jesús I. , Fernández Martín Juan José 
Published: November 2016

<p>The Convent of Santa Clara in Toro (Zamora) was founded in the mid-13<sup>th</sup> century. After destruction during the Castilian civil struggles of the last years of this century, its fabric was rebuilt and it was inhabited again by the Clarissan nuns, who still occupy it. Its architecture corresponds for the most part to its early-14<sup>th</sup> century rebuilding, even though it is concealed by works carried out from the 16<sup>th</sup> to the 18<sup>th</sup> centuries, so that it is apparently a Baroque complex. In the 1950s, in the choir of this Medieval hidden structure, a set of wall paintings of the mid-14thcentury was brought to light (one of the most important set of wall paintings of the early Gothic period ever found in Castile), but they were immediately detached from the walls and sold. It was only after a combination of circumstances that they came back to Toro to be installed in another building, the church of San Sebastián de los Caballeros, transformed into a museum. As a consequence of all these operations, the arrangement and sense of these wall paintings was lost. The virtual three-dimensional (3D) reconstruction, based on a deep analysis and criticism of historical sources and on a close inspection and photogrammetric recording of the original room once occupied by the wall paintings, enables us to place them back in their original context through the use of rendering techniques, so recovering one of the most exciting spaces of female devotion of the Castilian 14thcentury.</p>
North African dust transport toward the western Mediterranean basin: atmospheric controls on dust source activation and transport pathways during June–July 2013
Authors: Schepanski Kerstin , Mallet Marc , Heinold Bernd , Ulrich Max 
Published: November 2016

Abstract. Dust transported from north African source region toward the Mediterranean basin and Europe is a ubiquitous phenomenon in the Mediterranean region. Winds formed by large-scale pressure gradients foster dust entrainment into the atmosphere over north African dust source regions and advection of dust downwind. The constellation of centers of high and low pressure determines wind speed and direction, and thus the chance for dust emission over northern Africa and transport toward the Mediterranean. We present characteristics of the atmospheric dust life cycle determining dust transport toward the Mediterranean basin with focus on the ChArMEx (Chemistry-Aerosol Mediterranean Experiment) special observation period in June and July 2013 using the atmosphere–dust model COSMO-MUSCAT (COSMO: COnsortium for Small-scale MOdeling; MUSCAT: MUltiScale Chemistry Aerosol Transport Model). Modes of atmospheric circulation are identified from empirical orthogonal function (EOF) analysis of the geopotential height at 850 hPa and compared to EOFs calculated from 1979–2015 ERA-Interim reanalysis. Two different phases are identified from the first EOF, which in total explain 45 % of the variance. They are characterized by the propagation of the subtropical ridge into the Mediterranean basin, the position of the Saharan heat low and the predominant Iberian heat low, and discussed illustrating a dipole pattern for enhanced (reduced) dust emission fluxes, stronger (weaker) meridional dust transport, and consequent increased (decreased) atmospheric dust concentrations and deposition fluxes. In the event of a predominant high-pressure zone over the western and central Mediterranean (positive phase), a hot spot in dust emission flux is evident over the Grand Erg Occidental, and a reduced level of atmospheric dust loading occurs over the western Mediterranean basin. The meridional transport in northward direction is reduced due to prevailing northerly winds. In case of a predominant heat low trough linking the Iberian and the Saharan heat low (negative phase), meridional dust transport toward the western Mediterranean is increased due to prevailing southerly winds resulting in an enhanced atmospheric dust loading over the western Mediterranean. Altogether, results from this study illustrate the relevance of knowing dust source location and characteristics in concert with atmospheric circulation. The study elaborates on the question of the variability of summertime dust transport toward the Mediterranean and Europe with regard to atmospheric circulation conditions controlling dust emission and transport routes of Saharan dust, exemplarily for the 2-month period of June–July 2013. Ultimately, outcomes from this study contribute to the understanding of the variance in dust transport into a populated region.
Using Landsat Thematic Mapper (TM) sensor to detect change in land surface temperature in relation to land use change in Yazd, Iran
Authors: Zareie Sajad , Khosravi Hassan , Nasiri Abouzar , Dastorani Mostafa 
Published: November 2016

Abstract. Land surface temperature (LST) is one of the key parameters in the physics of land surface processes from local to global scales, and it is one of the indicators of environmental quality. Evaluation of the surface temperature distribution and its relation to existing land use types are very important to the investigation of the urban microclimate. In arid and semi-arid regions, understanding the role of land use changes in the formation of urban heat islands is necessary for urban planning to control or reduce surface temperature. The internal factors and environmental conditions of Yazd city have important roles in the formation of special thermal conditions in Iran. In this paper, we used the temperature–emissivity separation (TES) algorithm for LST retrieving from the TIRS (Thermal Infrared Sensor) data of the Landsat Thematic Mapper (TM). The root mean square error (RMSE) and coefficient of determination (R2) were used for validation of retrieved LST values. The RMSE of 0.9 and 0.87 °C and R2 of 0.98 and 0.99 were obtained for the 1998 and 2009 images, respectively. Land use types for the city of Yazd were identified and relationships between land use types, land surface temperature and normalized difference vegetation index (NDVI) were analyzed. The Kappa coefficient and overall accuracy were calculated for accuracy assessment of land use classification. The Kappa coefficient values are 0.96 and 0.95 and the overall accuracy values are 0.97 and 0.95 for the 1998 and 2009 classified images, respectively. The results showed an increase of 1.45 °C in the average surface temperature. The results of this study showed that optical and thermal remote sensing methodologies can be used to research urban environmental parameters. Finally, it was found that special thermal conditions in Yazd were formed by land use changes. Increasing the area of asphalt roads, residential, commercial and industrial land use types and decreasing the area of the parks, green spaces and fallow lands in Yazd caused a rise in surface temperature during the 11-year period.
Presence of rapidly degrading permafrost plateaus in south-central Alaska
Authors: Jones Benjamin M. , Baughman Carson A. , Romanovsky Vladimir E. , Parsekian Andrew D. , Babcock Esther L. , Stephani Eva , Jones Miriam C. , Grosse Guido , Berg Edward E. 
Published: November 2016

Abstract. Permafrost presence is determined by a complex interaction of climatic, topographic, and ecological conditions operating over long time scales. In particular, vegetation and organic layer characteristics may act to protect permafrost in regions with a mean annual air temperature (MAAT) above 0 °C. In this study, we document the presence of residual permafrost plateaus in the western Kenai Peninsula lowlands of south-central Alaska, a region with a MAAT of 1.5 ± 1 °C (1981–2010). Continuous ground temperature measurements between 16 September 2012 and 15 September 2015, using calibrated thermistor strings, documented the presence of warm permafrost (−0.04 to −0.08 °C). Field measurements (probing) on several plateau features during the fall of 2015 showed that the depth to the permafrost table averaged 1.48 m but at some locations was as shallow as 0.53 m. Late winter surveys (augering, coring, and GPR) in 2016 showed that the average seasonally frozen ground thickness was 0.45 m, overlying a talik above the permafrost table. Measured permafrost thickness ranged from 0.33 to  >  6.90 m. Manual interpretation of historic aerial photography acquired in 1950 indicates that residual permafrost plateaus covered 920 ha as mapped across portions of four wetland complexes encompassing 4810 ha. However, between 1950 and ca. 2010, permafrost plateau extent decreased by 60.0 %, with lateral feature degradation accounting for 85.0 % of the reduction in area. Permafrost loss on the Kenai Peninsula is likely associated with a warming climate, wildfires that remove the protective forest and organic layer cover, groundwater flow at depth, and lateral heat transfer from wetland surface waters in the summer. Better understanding the resilience and vulnerability of ecosystem-protected permafrost is critical for mapping and predicting future permafrost extent and degradation across all permafrost regions that are currently warming. Further work should focus on reconstructing permafrost history in south-central Alaska as well as additional contemporary observations of these ecosystem-protected permafrost sites south of the regions with relatively stable permafrost.
Tensiones mundiales, multipolaridad relativa y bloques de poder en una nueva fase de la crisis del orden mundial
Authors: Merino Gabriel Esteban 
Published: November 2016

Nos encontramos ante una nueva fase la crisis del orden mundial, cuya característica principal es el enfrentamiento político directo y en territorios principales entre los bloques de poder centrales del “norte global” y los bloques de poder emergentes, profundizando la situación de multipolaridad relativa. Esta nueva situación, que podemos ubicar a partir del estallido del conflicto en Ucrania, es presentada resumidamente en este trabajo a partir de los siguientes puntos: 1) el planteamiento del problema (qué está en juego en Ucrania) en relación a la crisis del orden mundial; 2) el eje estratégico Moscú-Beijing, los BRICS y el enfrentamiento con “Occidente”; 3) “Occidente” y sus posiciones: las diferencias estratégicas en Estados Unidos y las contradicciones con el núcleo euro (Alemania-Francia); 4) el impacto y los desafíos sobre América Latina como bloque de poder emergente.
Enkele kanttekeningen bij het wetsvoorstel bestuur en toezicht rechtspersonen
Authors: Bartman S.M. , de Groot C. , Nijland J. , Wuisman I.S. 
Published: November 2016

Enkele kanttekeningen bij het wetsvoorstel bestuur en toezicht rechtspersonen
Met het wetsvoorstel voor de Wet bestuur en toezicht rechtspersonen wordt beoogd de kwaliteit van bestuur en toezicht bij verenigingen, coöperaties, onderlinge waarborgmaatschappijen en stichtingen te verbeteren. In dit artikel bespreken de auteurs kort enkele aspecten van het wetsvoorstel in het licht van de doelstelling en de bruikbaarheid in de praktijk.