bluuebunny/crossref_metadata_2025_split huggingface dataset:
Challenges in Fine Feature Solder Paste Printing for SiP Applications
Authors: Pei-Lim Sze , Thum Kenneth , Mackie Andy 
Published: November 2016

Abstract
The rapid development in the Internet of Things (IoT) has seen a surge in demand for System-in-Package (SiP), which is capable of packing more functionality into a single package with a small form factor. This continues to push miniaturization to an even greater level, therefore creating assemblies with smaller components and greater density.
01005 passive components are being used in most of the current SiP technology and the industry is looking at utilizing 008004 passive components for the next generation SiP. The stencil aperture design for 008004 will likely be about half of 01005, and a finer powder size solder paste will be used. The stencil design, stencil thickness, and the types of stencils being used, are crucial in achieving good solder paste printing performance. Due to the need of squeezing more components into a SiP, the gap between neighboring pads can be as close as 50μm; hence, it is crucial to avoid solder bridging for such applications. This paper will discuss the challenges in achieving consistent solder paste printing performance for fine feature applications using Type 6 (5–15μm) powder size solder paste. Test results with different stencil designs, printing parameters, and different solder pastes will be discussed in detail.
Digital Manufacturing and Performance Testing for Military Grade Application Specific Electronic Packaging (ASEP)
Authors: Newton C. Mike , Deffenbaugh Paul I. , Church Kenneth H. , Crane Nathan B. , Neff Clayton 
Published: November 2016

I. Abstract
This paper will discuss the development of additive manufacturing as a process integration methodology for printed electronics and 3D printed structures. This integration enables the ability to move from printed circuit boards (PCBs) to printed circuit structures (PCS). Historically packaging has been identified as a hierarchical (or levels) approach to interconnect electronic products or systems. Level one packaging addresses the interconnection between bare die and the module while level four moves up in the packaging chain to connections between subassemblies. With the advent of digital manufacturing and emergence of more robust materials, the enabling technology provides a manufacturing tool for building electronic packages with integrated passives (some printed) and actives. This further enables the capability to adjust the form factor to the mission or product requirements - also known as personalization. This ability to become form factor agnostic has produced the ability for printing or digitally manufacturing application specific electronic packages, ASEPs. With this emerging capability it begs the question of reliability and in particular to qualification for harsh environment applications. This paper will discuss the application of current standards, Mil-Std-883 or JESD93 for example and how these might be applied to ASEPs and to also explore the development of new or hybridization of current standards.
Addressing Next Generation Packaging and IoT with Glass Solutions
Authors: Shorey Aric , Lu Rachel , Adriance Kevin , Smith Gene 
Published: November 2016

Abstract
New requirements are emerging in electronics packaging. The ever-growing need for solutions for mobile communications and sensors that address the Internet of Things (IoT) brings about interesting new challenges. RF applications strive to move to higher frequency bands, fan-out technology is being leveraged as an effective way to address interconnect demands, and there is a continuous search for more cost-effective solutions for difficult packaging challenges. Glass provides numerous opportunities to address these needs. As an insulator, glass has low electrical loss, particularly at high frequencies. The relatively high stiffness and ability to adjust coefficient of thermal expansion helps optimize warp in glass core substrates, and manage bonded stacks leveraging TGV and carrier applications. Glass forming processes allow to form in a panel format as well as wafer format at thicknesses as low as 100 μm, giving opportunities to optimize or eliminate current polishing type manufacturing methods and address packaging challenges in a cost effective way. As the industry adopts glass solutions, significant advancements have been made in downstream processes such as glass handling and via/surface metallization. Of particular interest is the ability to leverage tool sets and processes for panel fabrication to enable cost structures desired by the industry. We will provide the latest demonstrations of electrical, thermal and mechanical performance and reliability as well as describe areas where glass is being leveraged to achieve goals of next generation products.
3D SiP Assembly and Reliability for Glass Substrate with Through Vias
Authors: Tain Ra-Min , Hu Dyi-Chung , Yang Kai-Ming , Chen Yu-Hua , Chen Jui-Tang , Liu De-Shiang , Lin Chen-Hao 
Published: November 2016

Abstract
Applications of Glass substrate for high performance system-in-package (SiP) products have gradually become a promising technology in recent years. Research and development activities are reported in many journal papers and conferences [1,2]. Consortiums and Alliances are also formed to gather worldwide efforts for developing glass technology. In the past, we have published our development efforts on the process of producing glass substrate with through via and build-up redistribution circuit layers (RDLs) [3]. N. Koizumi [4] first reported glass reliability issues in 2013; and the phenomena he called SE-WA-RE has caused a great concern of using glass as a substrate. Model simulations have indicated that the glass crack is related to the stress buildup by the materials and structure. In this study, we selected a dielectric material/structure set that is designed to be less stressful to the glass substrate. A better reliability result can be expected.
In this paper, we will discuss an assembly structure of SiP module using the glass substrate with through-glass via (TGV) where the diameter of TGV is 100μm with thickness at 200μm. The copper plating technique to form the through via conductor is called direct-metal-on-glass (DMoG) which deposits titanium and copper directly on glass both in the wall of through vias and on glass surfaces of both sides. The first RDL is formed on both surfaces of glass substrate by semi-additive plating (SAP); then followed by build-up RDLs on top of the DMoG RDLs on both sides of the substrate also by SAP with interconnect vias to form connections between DMoG RDLs and build-up RDLs. Finally, solder mask is applied on both sides of the glass substrate leaving pad openings (SRO) for surface finish, die mounting and printed-circuit board connection purposes. At die mounting side, the SRO is 60μm in diameter with minimum pitch at 150μm. The TGV conductors connect the DMoG RDLs on both sides of the substrate. A mechanical test die with 18μm bump diameter is mounted on the build-up RDL at the substrate top side with daisy-chain design both in the test die and TGV substrate RDLs. Thus, the daisy-chain connection can go from the build-up RDL of the substrate back side to the test die on the top side of the substrate. 200 thermal-cycling test (TCT) has been performed and the daisy-chain resistances are measured before and after the 200 TCTs. It is found that 96% of daisy-chains have less than 10% of resistance change after 200 TCTs.
Package Thickness - Ultrathin WLFO (Wafer-Level Fan-Out)
Authors: O'Toole Eoin , Kroehnert Steffen , Campos José , Barbosa Virgilio , Dias Leonor 
Published: November 2016

Abstract
NANIUM's Fan-Out Wafer-Level Packaging technology WLFO (Wafer-Level Fan-Out) is based on embedded Wafer-Level Ball Grid Array technology eWLB of Infineon Technologies [1]. Since it′s invention almost 10 years ago, it became the leading technology for Fan-Out Wafer-Level packages. The WLFO technology is based upon the reconstitution of KGD (known good die) from incoming device wafer, independent of wafer diameter and material, to recon wafer format of active semiconductor dies or other active/passive components separated by mold compound applied through compression molding on a temporary mold carrier. The resulting recon wafer can be processed in standard wafer processing equipment.
One of the challenges for the future of semiconductor packaging is reduction of the board level volume real estate occupied by each component. With the drive towards lower profile end user devices incorporating large display area and battery life the three dimensional space available for semiconductor packages is diminishing. It is well known that WLFO single die packaging but even more significant system integration enables the shrinkage of the XY footprint of the package through flexible very dense heterogeneous system-in-package integration [2]. But one of the disruptive advantages of the substrate-less WLFO technology is to also permit significant reduction of the overall package height (Z). A total package height for a BGA package including solder balls &lt;500um and for a LGA package with solder land pads only &lt;300um is achievable today, and further development towards even thinner packages is on the way.
High viscosity paste dosing for microelectronic applications
Authors: Thomas T. , Voges S. , Braun T. , Raatz S. , Kahle R. , Becker K.-F. , Koch M. , Fliess M. , Bauer J. , Schneider-Ramelow M. , Lang K.-D. 
Published: November 2016

AbstractToday's microelectronics packaging especially for SiPs relies on the processing of a wide variety of materials Such as materials for components, substrates, contact materials (solder & adhesives) and encapsulants. Most materials are processed as bulk material but precision dosing of pastes is key to many assembly processes. Examples are dosing of solder paste, typically done by stencil printing, underfilling for Flip Chip encapsulation, typically done by dispensing or jetting, or glob top encapsulation of Chip on Board assemblies, where also dispensing is the typical process. When working with those paste materials, viscosity is one of the key parameters for processing, and viscosities too high do not allow dosing of the materials, not even to transport the material from a reservoir to the dosing head, which may be a simple needle or a jet valve. [1,2]To overcome this obstacle, i.e. to dose materials of high viscosity precisely and homogeneously from a syringe to the dosing head, a research program has been set up, where Vermes microdispensing as a valve manufacturer and TU Berlin/IZM as a research institute are cooperating. TU Berlin is working on material rheology effects and flow models; Vermes is researching valve modifications and material flow path optimization. Core of the research is to find methods that allow a reduction of paste viscosity without leading to irreversible changes in the material, as would be the case when simply applying heat to the paste.As reference process for material dosing, FO-WLP has been chosen, materials selected for the investigations are glob top dam and fill material and liquid molding compound – using both rheological experiments as well as actual material dosing and processing. Apart from temperature, mechanical and ultrasonic stimulation of the material have been evaluated to achieve optimized dosing of high viscous pastes,As a result, a first description of paste behavior during processing is given, being the basis for future work towards homogeneous precision dosing of high viscous pastes for microelectronic applications.
3D TSV-based Inductor Design for a Secure Internet of Things
Authors: Kim Bruce , Cho Sang-Bock 
Published: November 2016

Abstract
This paper describes the design and modeling of through-silicon via (TSV)-based high-density 3D inductors for Internet of Things (IoT) applications and presents some possible challenges for TSV-based inductors in IoT applications. For cybersecurity infrastructure, we designed IoT with hardware security in mind. We provide a secure design for Internet of Things based on secure 3D inductors and then show case studies of high-density RF packages with TSV-based inductors that require hardware security, such as military applications. We use ferromagnetic materials to achieve high inductance with good quality factor.
Simulation and Measurement of Power Distribution Networks (PDN)
Authors: (Alvin) Pin Jen Wang , Islam Sharmin , Barlow Fred , Elshabini Aicha 
Published: November 2016

Abstract
In this publication, signal integrity issues of Power Distribution Networks (PDNs) are addressed (to insure acceptable quality of signals within); Transmission line effects, Crosstalk, and Impedance mismatch. Power Integrity issues of PDNs are also addressed (to insure acceptable quality of power delivery within); Voltage drop, High impedance, Parasitic Via inductances, and Noise coupling. In this work, ANSYS™ HFSS 2013 FEM simulation techniques development, adaptive meshing, and convergence to S-parameters, Differential S-parameters, and Z-parameters to design and simulate PDNs under different conditions and the results are compared to measurements performed in our laboratories.
Spurious Turn-On inside a Power Module of Paralleled SiC MOSFETs
Authors: Miao Zichen , Ngo Khai D. T. 
Published: November 2016

Abstract
Silicon carbide (SiC) dice are often paralleled to realize power modules with high-current rating. Owing to the large network of interconnect (parasitic) impedances, terminal waveforms could appear benign while the dice experience detrimental fault currents generated by spurious cross-turn-on. This paper will quantify the non-uniform distribution of current stress and switching energy among the dice, as well as the penalty caused by cross-turn-on, versus layout symmetry, number of dice, gate resistance, input voltage, and load current.
Cross-turn-on currents inside a module increase the high-side switching energy and total switching energy by 44% and 20%, respectively, at 800 V / 300 A. Peak cross-turn-on current of the symmetrical module is only 16% of that of asymmetrical module at nominal condition. Symmetrical layout greatly decreases the cross-turn-on currents without increasing the total switching energy.
Four modules are constructed based on the asymmetrical layout to explore how number of dice influences cross-turn-on and switching energy. Peak cross-turn-on current and switching energy of the six-die module are 134% and 36% higher than those of the one-die module, respectively. Severity of cross-turn-on soars as number of dice increases.
Digital Segusio: from models generation to urban reconstruction
Authors: Spanò Antonia , Chiabrando Filiberto , Dezzani Livio , Prencipe Antonio 
Published: November 2016

<p>The reconstructive study of the urban arrangement of Susa in the 4th century arose from the intention to exploit some resources derived from local studies, and survey activities, fulfilled by innovative methods from which the modelling of architectural heritage (AH) and virtual reconstructions are derived. The digital Segusio presented in this paper is the result of intensive discussion and exchange of data and information during the urban landscape documentation activities, and due to the technology of virtual model generation, making it possible to recreate the charm of an ancient landscape. The land survey has been accomplished using aerial and terrestrial acquisition systems, mainly through digital photogrammetry from UAV (Unmanned Aerial Vehicle) and terrestrial laser scanning. Results obtained from both the methods have been integrated into the medium scale geographical data from the regional map repository, and some processing and visualization supported by GIS (Geographical Information System) has been achieved. Subsequently, with the help of accurate and detailed DEM (Digital Elevation Model) and other architectural scale models related to the ancient heritage, this ancient landscape was modelled. The integration of the history of this city with digital and multimedia resources will be offered to the public in the city museum housed in the restored castle of Maria Adelaide (Savoy dynasty, 11th century), which stands in the place where the acropolis of the city of Susa lay in ancient times.</p>
Aerosol arriving on the Caribbean island of Barbados: physical properties and origin
Authors: Wex Heike , Dieckmann Katrin , Roberts Greg C. , Conrath Thomas , Izaguirre Miguel A. , Hartmann Susan , Herenz Paul , Schäfer Michael , Ditas Florian , Schmeissner Tina , Henning Silvia , Wehner Birgit , Siebert Holger , Stratmann Frank 
Published: November 2016

Abstract. The marine aerosol arriving at Barbados (Ragged Point) was characterized during two 3-week long measurement periods in November 2010 and April 2011, in the context of the measurement campaign CARRIBA (Cloud, Aerosol, Radiation and tuRbulence in the trade wInd regime over BArbados). Through a comparison between ground-based and airborne measurements it was shown that the former are representative of the marine boundary layer at least up to cloud base. In general, total particle number concentrations (Ntotal) ranged from as low as 100  up to 800 cm−3, while number concentrations for cloud condensation nuclei (NCCN) at a supersaturation of 0.26 % ranged from some 10 to 600 cm−3. Ntotal and NCCN depended on the air mass origin. Three distinct types of air masses were found. One type showed elevated values for both Ntotal and NCCN and could be attributed to long-range transport from Africa, by which biomass burning particles from the Sahel region and/or mineral dust particles from the Sahara were advected. The second and third type both had values for NCCN below 200 cm−3 and a clear minimum in the particle number size distribution (NSD) around 70 to 80 nm (Hoppel minimum). While for one of these two types the accumulation mode was dominating (albeit less so than for air masses advected from Africa), the Aitken mode dominated the other and contributed more than 50 % of all particles. These Aitken mode particles likely were formed by new particle formation no more than 3 days prior to the measurements. Hygroscopicity of particles in the CCN size range was determined from CCN measurements to be κ  =  0.66 on average, which suggests that these particles contain mainly sulfate and do not show a strong influence from organic material, which might generally be the case for the months during which measurements were made. The average κ could be used to derive NCCN from measured number size distributions, showing that this is a valid approach to obtain NCCN. Although the total particulate mass sampled on filters was found to be dominated by Na+ and Cl−, this was found to be contributed by a small number of large particles ( >  500 nm, mostly even in the super-micron size range). Based on a three-modal fit, a sea spray mode observed in the NSDs was found to contribute 90 % to the total particulate mass but only 4 to 10 % to Ntotal and up to 15 % to NCCN. This is in accordance with finding no correlation between Ntotal and wind speed.
Semi-automated calibration method for modelling of mountain permafrost evolution in Switzerland
Authors: Marmy Antoine , Rajczak Jan , Delaloye Reynald , Hilbich Christin , Hoelzle Martin , Kotlarski Sven , Lambiel Christophe , Noetzli Jeannette , Phillips Marcia , Salzmann Nadine , Staub Benno , Hauck Christian 
Published: November 2016

Abstract. Permafrost is a widespread phenomenon in mountainous regions of the world such as the European Alps. Many important topics such as the future evolution of permafrost related to climate change and the detection of permafrost related to potential natural hazards sites are of major concern to our society. Numerical permafrost models are the only tools which allow for the projection of the future evolution of permafrost. Due to the complexity of the processes involved and the heterogeneity of Alpine terrain, models must be carefully calibrated, and results should be compared with observations at the site (borehole) scale. However, for large-scale applications, a site-specific model calibration for a multitude of grid points would be very time-consuming. To tackle this issue, this study presents a semi-automated calibration method using the Generalized Likelihood Uncertainty Estimation (GLUE) as implemented in a 1-D soil model (CoupModel) and applies it to six permafrost sites in the Swiss Alps. We show that this semi-automated calibration method is able to accurately reproduce the main thermal condition characteristics with some limitations at sites with unique conditions such as 3-D air or water circulation, which have to be calibrated manually. The calibration obtained was used for global and regional climate model (GCM/RCM)-based long-term climate projections under the A1B climate scenario (EU-ENSEMBLES project) specifically downscaled at each borehole site. The projection shows general permafrost degradation with thawing at 10 m, even partially reaching 20 m depth by the end of the century, but with different timing among the sites and with partly considerable uncertainties due to the spread of the applied climatic forcing.
Early diagnosis of genital mucosal melanoma: how good are our dermoscopic criteria?
Authors: Rogers Tova , Pulitzer Melissa , Marino Maria L. , Marghoob Ashfaq A. , Zivanovic Oliver , Marchetti Michael A. 
Published: November 2016

Background: There are limited studies on the dermoscopic features of mucosal melanoma, particularly early-stage lesions. Described criteria include the presence of blue, gray, or white colors, with a reported sensitivity of 100%. It is unclear if these features will aid in the detection of early mucosal melanoma or improve diagnostic accuracy compared to naked-eye examination alone.
Case: An Asian female in her fifties was referred for evaluation of an asymptomatic, irregularly pigmented patch of the clitoral hood and labia minora of unknown duration. Her past medical history was notable for Stage IV non-small cell lung cancer. She denied a personal or family history of skin cancer. Dermoscopic evaluation of the vulvar lesion revealed heterogeneous brown and black pigmentation mostly composed of thick lines. There were no other colors or structures present. As the differential diagnosis included vulvar melanosis and mucosal melanoma, the patient was recommended to undergo biopsy, which was delayed due to complications from her underlying lung cancer. Repeat dermoscopic imaging performed three months later revealed significant changes concerning for melanoma, including increase in size, asymmetric darkening, and the appearance of structureless areas and central blue and pink colors. Histopathological examination of a biopsy and subsequent resection confirmed the diagnosis of melanoma in situ.
Conclusion: Previously described dermoscopic features for mucosal melanoma may not have high sensitivity for early melanomas. Additional studies are needed to define the dermoscopic characteristics of mucosal melanomas that aid in early detection. Health care providers should have a low threshold for biopsy of mucosal lesions that show any clinical or dermoscopic features of melanoma, especially in older women.
From the editors
Authors: Value Language 
Published: November 2016

From the Editors
SPECIAL ISSUE: LANGUAGE VALUE IN MINORITY LITERATURES
In the wake of Nigerian independence and in contrast to African writers who took an essentialist view that equates language with cultural identity (Ngugi wa Thiong’o, for example), Chinua Achebe declared that “[a] language spoken by Africans on African soil, a language in which Africans write, justifies itself” (1975: 67). According to his vision, the colonizers’ languages, English and French, even if they were not African languages, because of their grasp on African history, were part and parcel of African experience. [...]