bluuebunny/crossref_metadata_2025 huggingface dataset:
Power Approaches for Implantable Medical Devices
Authors: Amar Achraf , Kouki Ammar , Cao Hung
Published: November 2015

Implantable medical devices have been implemented to provide treatment and to assess in vivo physiological information in humans as well as animal models for medical diagnosis and prognosis, therapeutic applications and biological science studies. The advances of micro/nanotechnology dovetailed with novel biomaterials have further enhanced biocompatibility, sensitivity, longevity and reliability in newly-emerged low-cost and compact devices. Close-loop systems with both sensing and treatment functions have also been developed to provide point-of-care and personalized medicine. Nevertheless, one of the remaining challenges is whether power can be supplied sufficiently and continuously for the operation of the entire system. This issue is becoming more and more critical to the increasing need of power for wireless communication in implanted devices towards the future healthcare infrastructure, namely mobile health (m-Health). In this review paper, methodologies to transfer and harvest energy in implantable medical devices are introduced and discussed to highlight the uses and significances of various potential power sources.
ATV-Related Workers’ Compensation Claims in Montana, 2007–2012
Authors: Lagerstrom Elise , Gilkey David , Elenbaas David , Rosecrance John
Published: November 2015

The objective of this study was to analyze workers’ compensation injury and fatality data associated with the occupational use of all-terrain vehicles (ATVs) in Montana. Data were provided by the Montana Department of Labor and Industry Workers’ Compensation Injury and Occupational Disease Database. Claims were identified based on a search of injury codes related to vehicular claims and then narrowed by a keyword search for events related to ATVs. Two hundred and fifteen ATV-related claims were identified between 2007 and 2012. The majority of claimants were identified as male (85%), with 23% of total claims between the ages 20–29 at the time of injury. The agriculture industry accounted for 59% of all claims. The results of this investigation indicated that the cost of occupational ATV injuries and deaths during the study period totaled nearly $2,600,000. The agriculture industry is disproportionally represented in ATV workers’ compensation claims in Montana. Characterizing and understanding the risk factors associated with occupational-related ATV injuries is critical for developing strategies and programs aimed at injury prevention. Evaluating the gaps in data acquisition and reporting could aid in ensuring comprehensive and complete future investigations of ATV incidents.
Removal of Dimethyl Sulfide from Aqueous Solution Using Cost-Effective Modified Chicken Manure Biochar Produced from Slow Pyrolysis
Authors: Nguyen Minh-Viet , Lee Byeong-Kyu
Published: November 2015

This study investigated the characteristics of using a cost-effective, amine-modified biochar (BC) derived from chicken manure for removing dimethyl sulfide (DMS) from an aqueous solution. The amine-modified BC showed much higher adsorption of DMS compared to commercial activated carbons under varying conditions of contact time, initial concentration, and adsorbent dosage. The DMS removal efficiency increased as the adsorbent dosage was increased from 0.01 to 0.25 g and reached 92.4% even at the relatively low adsorbent dose of 0.015 g. The DMS adsorption capacity of the amine-modified BC (mg/g) increased with increasing DMS concentration, while the incremental rate of the removal efficiency decreased. The adsorption process was well explained by a pseudo-second-order kinetics model. The adsorption of DMS is more appropriately described by the Freundlich isotherm (R2 = 0.989) than by the Langmuir isotherm (R2 = 0.942). The DMS removal efficiency was only reduced by 23.4% even after 10 recovery cycles. The surface area of the amine-modified BC was much higher (9.4 ± 1.2 times) than that of the unmodified BC. The amine-modified BC with a high surface area of 334.6 m2/g can be utilized as a cheap and effective alternative adsorbent to commercial activated carbon for DMS removal.
Hazard Assessment of Debris Flows in the Reservoir Region of Wudongde Hydropower Station in China
Authors: Niu Cencen , Wang Qing , Chen Jianping , Zhang Wen , Xu Liming , Wang Ke
Published: November 2015

The outbreak of debris flows in a reservoir region can affect the stability of hydropower stations and threaten the lives of the people living downstream of dams. Therefore, determining the hazard degree of debris flows in a reservoir region is of great importance. SPOT5 remote sensing images and digital elevation models are introduced to determine the characteristics of debris-flow catchments. The information is acquired through comprehensive manual investigation and satellite image interpretation. Ten factors that influence debris flow are extracted for the hazard assessment. The weight of these factors is determined using the analytic hierarchy process method. As a multi-criterion decision analysis method, fuzzy synthetic evaluation is applied for hazard assessment.
Botulinum Toxin Type A Induces Changes in the Chemical Coding of Substance P-Immunoreactive Dorsal Root Ganglia Sensory Neurons Supplying the Porcine Urinary Bladder
Authors: Bossowska Agnieszka , Lepiarczyk Ewa , Mazur Urszula , Janikiewicz Paweł , Markiewicz Włodzimierz
Published: November 2015

Botulinum toxin (BTX) is a potent neurotoxin which blocks acetylcholine release from nerve terminals, and therefore leads to cessation of somatic motor and/or parasympathetic transmission. Recently it has been found that BTX also interferes with sensory transmission, thus, the present study was aimed at investigating the neurochemical characterization of substance P-immunoreactive (SP-IR) bladder-projecting sensory neurons (BPSN) after the toxin treatment. Investigated neurons were visualized with retrograde tracing method and their chemical profile was disclosed with double-labelling immunohistochemistry using antibodies against SP, calcitonin gene-related peptide (CGRP), pituitary adenylate cyclase activating polypeptide (PACAP), neuronal nitric oxide synthase (nNOS), galanin (GAL), calbindin (CB), and somatostatin (SOM). In the control group (n = 6), 45% of the total population of BPSN were SP-IR. Nearly half of these neurons co-expressed PACAP or CGRP (45% and 35%, respectively), while co-localization of SP with GAL, nNOS, SOM or CB was found less frequently (3.7%, 1.8%, 1.2%, and 0.7%, respectively). In BTX-treated pigs (n = 6), toxin-injections caused a decrease in the number of SP-IR cells containing CGRP, SOM or CB (16.2%, 0.5%, and 0%, respectively) and a distinct increase in these nerve cells immunopositive to GAL (27.2%). The present study demonstrates that BTX significantly modifies the chemical phenotypes of SP-IR BPSN.
Harnessing the Power of Onco-Immunotherapy with Checkpoint Inhibitors
Authors: Rajani Karishma , Vile Richard
Published: November 2015

Oncolytic viruses represent a diverse class of replication competent viruses that curtail tumor growth. These viruses, through their natural ability or through genetic modifications, can selectively replicate within tumor cells and induce cell death while leaving normal cells intact. Apart from the direct oncolytic activity, these viruses mediate tumor cell death via the induction of innate and adaptive immune responses. The field of oncolytic viruses has seen substantial advancement with the progression of numerous oncolytic viruses in various phases of clinical trials. Tumors employ a plethora of mechanisms to establish growth and subsequently metastasize. These include evasion of immune surveillance by inducing up-regulation of checkpoint proteins which function to abrogate T cell effector functions. Currently, antibodies blocking checkpoint proteins such as anti-cytotoxic T-lymphocyte antigen-4 (CTLA-4) and anti-programmed cell death-1 (PD-1) have been approved to treat cancer and shown to impart durable clinical responses. These antibodies typically need pre-existing active immune tumor microenvironment to establish durable clinical outcomes and not every patient responds to these therapies. This review provides an overview of published pre-clinical studies demonstrating superior therapeutic efficacy of combining oncolytic viruses with checkpoint blockade compared to monotherapies. These studies provide compelling evidence that oncolytic therapy can be potentiated by coupling it with checkpoint therapies.
Optimal Sensor Placement for Leak Location in Water Distribution Networks using Evolutionary Algorithms
Authors: Casillas Myrna , Garza-Castañón Luis , Puig Vicenç
Published: November 2015

In this paper, a sensor placement approach to improve the leak location in waterdistribution networks is proposed when the leak signature space (LSS) method is used.The sensor placement problem is formulated as an integer optimization problem where thecriterion to be minimized is the number of overlapping signature domains computed fromthe original LSS representation. First, a semi-exhaustive search approach based on a lazyevaluation mechanism ensures optimal placement in the case of low complexity scenarios.For more complex cases, a stochastic optimization process is proposed, based on eitherthe genetic algorithms (GAs) or particle swarm optimization (PSO). Experiments on twodifferent networks are used to evaluate the performance of the resolution methods, as well asthe efficiency achieved in the leak location when using the sensor placement results.
Biometeorologinės prognozės kaip adaptacijos priemonė klimato kaitos kontekste
Authors: Nariūnaitė Ieva , Liukaitytė Judita
Published: November 2015

Klimato kaitos ir žmogaus tarpusavio ryšys yra neabejotinai stiprus, jis turi nesustabdomą tąsą laike, kuri lemia vis didesnę fizinę ar psichologinę žmogaus reakciją. Biometeorologija gerai perteikia jųdviejų sąsajas ir apibūdina esamą bei būsimą klimato kaitos poveikį, žmogaus pojūčius tokioje aplinkoje. Tad šiame darbe aptariamos Lietuvoje plėtojamos biometeorologinės prognozės, jų sudarymo principai, galimybės bei nauda prisitaikant prie klimato kaitos.
First verified record of the ant genus Calyptomyrmex (Hymenoptera: Formicidae) from India, along with a revised key to known Indomalayan species
Authors: Akbar Shahid , Bharti Himender
Published: November 2015

The members of genus Calyptomyrmex are mostly encountered under rotten logs, in the soil, under stones and in leaf litter samples. These ants are seldom in collections making estimation of their true distributional patterns problematic (Shattuck 2011). The deep antennal scrobes and the unique configuration of the clypeus are distinct to the genus (Bolton 1981).

Herein Calyptomyrmex wittmeri Baroni Urbani, 1975 is redescribed and reported for the first time from India. This also confirms the first valid published record of the genus from the country. The image hosted by AntWeb as C. vedda (CASENT0280817; AntWeb 2015b) collected by Besuchet, Löbl, Mussard from Kerala, India and identified by Brown is actually C. wittmeri (Brown was uncertain of his determination of C. vedda and cautiously inserted an interrogation point in front of his determination). Two workers recently collected at Salim Ali Bird Sanctuary, Kerala present similarities to the specimen identified by Brown. However, characters as the lack of well-developed promesonotal suture, absence of clavate setae, and narrow petiolar node, concur with the diagnosis of C. wittmeri. A revised key to known Indomalayan species of the genus is provided herewith.
Vasoactive Therapy in Systemic Sclerosis: Real-life Therapeutic Practice in More Than 3000 Patients
Authors: Moinzadeh Pia , Riemekasten Gabriela , Siegert Elise , Fierlbeck Gerhard , Henes Joerg , Blank Norbert , Melchers Inga , Mueller-Ladner Ulf , Frerix Marc , Kreuter Alexander , Tigges Christian , Lahner Nina , Susok Laura , Guenther Claudia , Zeidler Gabriele , Pfeiffer Christiane , Worm Margitta , Karrer Sigrid , Aberer Elisabeth , Bretterklieber Agnes , Genth Ekkehard , Simon Jan C. , Distler Joerg H.W. , Hein Ruediger , Schneider Matthias , Seitz Cornelia S. , Herink Claudia , Steinbrink Kerstin , Sárdy Miklos , Varga Rita , Mensing Hartwig , Mensing Christian , Lehmann Percy , Neeck Gunther , Fiehn Christoph , Weber Manfred , Goebeler Matthias , Burkhardt Harald , Buslau Michael , Ahmadi-Simab Keihan , Himsel Andrea , Juche Aaron , Koetter Ina , Kuhn Annegret , Sticherling Michael , Hellmich Martin , Kuhr Kathrin , Krieg Thomas , Ehrchen Jan , Sunderkoetter Cord , Hunzelmann Nicolas ,   The German Network for Systemic Scleroderma
Published: November 2015

Objective.

Vasculopathy is a key factor in the pathophysiology of systemic sclerosis (SSc) and the main cause for Raynaud phenomenon (RP), digital ulcers (DU), and/or pulmonary arterial hypertension (PAH). It is so far unknown how patients with SSc are treated with vasoactive agents in daily practice. To determine to which extent patients with SSc were treated with different vasoactive agents, we used data from the German Network for Systemic Scleroderma registry.

Methods.

The data of 3248 patients with SSc were analyzed.

Results.

Patients were treated with vasoactive drugs in 61.1% of cases (1984/3248). Of these, 47.6% received calcium channel inhibitors, followed by 34.2% treated with angiotensin-converting enzyme (ACE) inhibitors, 21.1% treated with intravenous (IV) prostanoids, 10.1% with pentoxifylline, 8.8% with angiotensin 1 receptor antagonists (AT1RA), 8.7% with endothelin 1 receptor antagonists (ET1RA), 4.1% with phosphodiesterase type 5 (PDE5) inhibitors, and 5.3% with others. Patients with RP received vasoactive therapy in 63.3% of cases, with DU in 70.1%, and with PAH in 78.2% of cases. Logistic regression analysis revealed that patients with PAH were significantly more often treated with PDE5 inhibitors and ET1RA, and those with DU with ET1RA and IV prostanoids. In addition, 41.8% of patients were treated with ACE inhibitors and/or AT1RA. Patients registered after 2009 received significantly more often ET1RA, AT1RA, and IV prostanoids compared with patients registered prior to 2005.

Conclusion.

These data clearly indicate that many patients with SSc do not yet receive sufficient vasoactive therapy. Further, in recent years, a marked change of treatment regimens can be observed.
Lectotypification of the name Polymnia maculata Cav. (Asteraceae: Millerieae)
Authors: Vitali Maira S.
Published: November 2015

The typification of the name Polymnia maculata Cav. is discussed and the illustration made by Cavanilles in 1795 is designated as the lectotype and the specimen MA 606169 is designated as epitype.
Pure Chemical Reduction of Tin Oxides to Metallic Tin by Atmospheric Plasma to Improve Interconnection Reflow of Pb-free Solders
Authors: Lee Kang-Wook , Sakuma Katsuyuki , Lombardi Thomas , Rowland Jason , Lewison David , Schulte Eric
Published: November 2015

Tin alloys are widely used as solder for electronic interconnections. Tin solder surfaces tend to have tin oxides which need to be removed to improve the yield of interconnection reflow processes such as flip chip joining. Conventionally, a strong flux is employed to remove these oxides, however this process has the drawbacks of leaving flux residue which can cause underfill delamination or require a high-cost cleaning process. As solder bump volumes and bump-to-bump spacing decrease, these problems become more difficult to manage in manufacturing. We propose the use of Atmospheric Plasma to reduce these oxides from the bump surfaces to enable the use of very light fluxes, or no flux at all. This process has the advantages of plasma surface preparation without the cost and throughput penalty of vacuum plasma processes. Such a process can increase throughput and yield while reducing the cost. We describe an experiment in which tin foils were treated with a reducing-chemistry Atmospheric Plasma process and then analyzed with X-ray photoelectron spectroscopy (XPS) and Auger Electron Spectroscopy (AES). AES depth profile analyses indicate that the thickness of tin oxides was significantly reduced by the plasma. There was no evidence for any etching of underlying elemental tin. These results suggest that tin oxides are reduced to metallic tin without etching of the underlying tin metal. In another similar experiment using semiconductor chips with SnAg solders, XPS results suggest that the tin oxides were again reduced to metallic tin. In flip chip joining, the joining process with such Atmospheric Plasma-treated chips achieved high interconnect yield, even in the case of poor quality solder balls with excessive oxidation. It is our understanding that the pure chemical reduction of tin oxides with atmospheric plasma in ambient had not been previously reported.
A Direct Digital Manufactured RFID System Applied to Teaching Antenna Theory to Pre-College Students
Authors: Rojas-Nastrucci Eduardo A. , Ramirez Ramiro A. , Murphy Sean T. , Newton Mike , Weller Thomas M.
Published: November 2015

Applications of RFID technology are continually increasing, solving problems related with keeping track of objects and persons. For instance, nowadays the fact of knowing the precise location of a shipment is considered essential. On the other hand, antenna principles often seem complicated when they are studied the first time; but the reality is that the main concepts could be explained in a simple and practical way. Furthermore, an early contact with these concepts generates a solid understanding of the phenomena. The RFID system presented in this work is intended to be used with pre-college students, being simple enough to ensure understanding, but also showing interesting antenna designs such as the sinuous antenna. The system is easy to reproduce, using Digital Direct Manufacturing (3D printing) to build it, and convenient to teach antenna principles to students at all levels. Screen printing was the metal deposition of choice since at the high school level this process is easily implemented. Screen printing kits purchased from a craft store can be obtained for less than fifty dollars and can accommodate the antenna design “graphics”. This process can be compared to that of screen printing t-shirts replacing paint with polymer conductive ink. A sinuous antenna is used for the reader and a meandered dipole for the tag. The tag design is flexible enough to allow students to adapt it to different shapes, hence, promoting their creativity.
Ensuring Suitability of Cu Wire Bonded ICs for Automotive Applications
Authors: McLeish James , Schueller Randy
Published: November 2015

The transition to replace gold with copper bond wires in semiconductor components, primarily driven by the ever increasing price of gold wire, has been under way for several years. Cu wire bonds (Cu-WBs) are technically more challenging than gold to produce, requiring improved designs, processes and equipment. After introduction in consumer products, their use is now migrating to automotive electronics where product integrity for quality, reliability and durability (QRD) and safety over 10–15 years in a demanding harsh environment is paramount, in addition to managing cost in the highly competitive global automotive market.

Reliability issues with some Cu wire bonded components detected during the rigorous product validation durability–reliability tests of automotive electronics, however, are starting to appear. The indications are that only optimized package design with well-controlled assembly processes are suitable for high reliability (hi-rel) harsh environment applications such as automotive, military and aerospace. A concern is that non-optimized Cu-WBs and package materials issues are being detected in module-level durability validation tests in parts that were qualified as automotive grade per AEC Q-100 or AEC-Q101. This article will explore the issues and discuss potential solutions as the Automotive Electronics Council (AEC) – the organization that defines requirements for automotive grade electronic components – works to update qualification procedures for evolving Cu-wire bond technology.
Isolation Resistance of Encapsulated Electrical Conductors and Terminations for Biomedical Applications
Authors: Marinis Thomas F. , Soucy Joseph W.
Published: November 2015

Implanted electronic medical devices are evolving into architectures that are comprised of multiple packages that require reliable, high density electrical interconnections. Both power and digital signals must be routed between devices on cables that are immersed in an ionic, electrically conductive medium. Electronics are typically housed in hermetic packages with electrical feed throughs that must also be protected from the implant environment. The polymer materials used to encapsulate cable conductors and terminations must be biocompatible, compliant and of minimal thickness. These requirements result in materials that are susceptible to ion diffusion and migration in electric fields. We have used finite element models to explore the effects of geometries, electric field intensity and material properties on the time dependent electrical isolation resistance of cables and terminations. Simple beaker tests have been used to evaluate the isolation resistance of samples under bias as a function of time to validate our finite element models.
Embedded passives on low profile Silicon substrate technology for Medical implants, Wearables and Internet of Things
Authors: Leruez Sébastien , Bunel Catherine
Published: November 2015

Innovation is a “Must” in medical implants, wearables and internet of things. IPDiA, as a center of excellence, is already closely involved with the key players of Medical devices adopting new implantable electrical stimulation technologies. Design flexibility, low leakage current, extended lifetime and the suppression of burn-in tests are making the main differences. This unique technology is also selected by consumer players for its ability to reduce final application size when the low thickness and innovative shapes are key drivers for wearable applications. This presentation will concentrate on the technology illustrated by several examples of solutions with innovative shapes, heterogeneous stacks with different form factors.
PERSPECTIVE ON REQUIRED PACKAGING TECHNOLOGIES FOR NEUROMORPHIC DEVICES
Authors: Orii Yasumitsu , Horibe Akihiro , Sueoka Kuniaki , Matsumoto Keiji , Aoki Toyohiro , Noma Hirokazu , Kohara Sayuri , Okamoto Keishi , Yamamichi Shintaro , Hosokawa Kohji , Mori Hiroyuki
Published: November 2015

Cognitive computing has capability of machine learning, recognition and proposal. It is essential to make human life richer, more productive and more intelligent. For the realization of the cognitive computing, an efficient and scalable non-von Neumann architecture inspired by the human brain structure has been developed and a device which demonstrates the concept was also built. This device mimics the signal processing of the human brain, packing one million neuron circuits in 4,096 cores. It consumes almost 1,000 times less energy per event compared with a state-of-the-art multiprocessor. However, one million neurons only correspond to those of the bee's brain, and to mimic the brains of higher order animals, the inter-chip wiring becomes much more important, because this kind of neuromorphic device requires a large number of parallel signal lines for massive parallel signal operations. 3D chip stacking is, of course, a crucial technology in achieving the device. Technologies associated with 3D stacking such as low cost TSV formation and fine-pitch interconnection, smaller than 10μm pitch technology are required. From the reliability point of view, the optimization of solder composition is also important. Injection Molded Solder (IMS) is well fit to this fine pitch interconnection, in terms of material optimization and low cost joints. As for the interposer, the build-up organic interposer is the most attractive candidates for the cost issue, but in the most top layer, ultra-fine pitch wiring with the line and space widths smaller than 1μm should be prepared. Lots of material and process innovations are necessary for the inter-chip connection for neuromorphic devices.
Temporary Bonding and Debonding Technologies to Enable Innovative Fan-Out Embedded Interposer for High-Density Applications
Authors: Lee Alvin , Su Jay , Liu Xiao , Hung Yin-Po , Lin Yu-Min , Huang Shin-Yi , Cheng Ren-Shin , Chang Tao-Chih
Published: November 2015

As requirements increase for mobile devices to be lighter and thinner and to operate at high speed and high bandwidth, innovations in wafer-level packaging have evolved to 3-D structures, such as package-on-package (PoP), fan-out integration, and through-silicon-via (TSV) interposer architectures. However, wafer-level packaging is still considered to be costly and slow in throughput due to wafer size limitations.

In this study, temporary bonding and debonding processes using mechanical or laser release technologies were applied in the fabrication process of an integrated embedded glass interposer as a foundation for 3-D integrated circuit (IC) packaging on panel-level packaging. Glass interposers having dimensions of 10 mm × 10 mm and a thickness of 120 μm were fabricated. The interposers had through-glass vias (TGVs) 25 μm in diameter and 3000 I/O pads of copper under-bump metallization (UBM) and were designed as a nearly full-array type. The interposers were supported by a temporary bonding material on silicon or glass wafers and embedded by built-up dielectric material on which fan-out redistribution circuit layers were deposited. For forming the pattern of the redistribution layer, a UV laser was used to form 75-μm-diameter blind vias, and conductive interconnections were made by a semi-additive process (SAP) using photolithography and electrolytic copper. The process of building up layers from the glass interposer to form an embedded fan-out interposer can eliminate a joining process required by traditional 2.5-D IC integration. Finally, the embedded fan-out carrier is separated from the glass or silicon wafer through a laser debonding process.

An experiment to study the correlation of bonding material and release material with built-up lamination in backside processes will be discussed in this paper to address full process integration on panel-size substrates. The combination of temporary bonding technology with mechanical or laser release technologies will pave the way for realizing cost-effective 3-D IC packaging on panel-level substrates.
A Novel Back-side Via Process For Low-cost TSV.
Authors: Sakuishi Toshiyuki , Murayama Takahide , Morikawa Yasuhiro
Published: November 2015

Recently, mobile devices, such as smart phone or tablet PC have spread widely, and data traffic is increasing rapidly. Data servers for them are required high-speed data processing and low power consumption. Devices for those equipments are required high-speed processing, high-density packaging and low power consumption. Most powerful way to achieve these goals are three-dimensional (3D) integration using TSV (Through Silicon Via) and 2.5D integration using silicon interposer. However, cost and reliability issues are pointed out. The radical problem about the long-term reliability of TSV production is not still solved. In particular, the management of barrier metal film deposition on the smooth surface is most important technology for Cu diffuse protection [1]. To solve these problems, we have been developing via last process. One of the major challenges to via last back-side via is high capacitor. For this problem, scallop-free high rate Si etching and low dielectric constant liner is effective. We have been developing scallop-free etching by direct etching method. [2,3,4] Direct etching method use mixture gas of SF6 and O2, forming a thin SiOx film on the sidewall, and achieves an anisotropic etching. Advantage of direct etching is smooth sidewall without scallop. Simultaneous etching and side wall protection do not generate periodic unevenness. The issue of the leakage current, which could be caused by sidewall roughness, has been studied. [5, 6] Moreover, since a thick fluorocarbon film does not adhered, reduce the load of cleaning step and the risk of peeling the insulating film. Direct etching method is superior to the taper angle controllability. Taper and scallop-free etch improve the deposition coverage and contribute cost reduction. On the other hand, Bosch etching also has some advantage. We have developed etching module which is capable of both direct etching and Bosch etching. As a result, we have developed new process which is combined direct etching and Bosch etching. It has a new value and potential.
Development and usability study of pre-applied inter chip fill for 3D-IC
Authors: Takeshita Kan , Ikemoto Makoto , Sugiyama Masaya , Yamamoto Hidehiro , Kiritani Hideki , Kawase Yashuhiro
Published: November 2015

Non-conductive paste type material which is called a high thermal conductive inter chip fill (HT-ICF) has been developed for joining of 3D integrated circuits through a pre-applied process. In this paper, we focused attention on practicability for industrial use of HT-ICF, such as curing speed and dispensability. We have optimized matrix and filler formulation to boost usability and also tested our HT-ICF to chip joining to check process capability using some kinds of test vehicles. Our newly developed HT-ICF has potential ability to replace current underfill process and can be applied to various types of 3D-IC where high thermal conductivity is indispensable.
Copper Oxide Direct Bonding of 200mm CMOS Wafers: Morphological and Electrical Characterization
Authors: Cavaco Celso , Peng Lan , De Leersnijder Koen , Guerrieri Stefano , Tezcan Deniz S. , Osman Haris
Published: November 2015

We show for the first time complete data on 200mm wafer to wafer copper oxide direct bonding of two metal levels. Both surface acoustic microscope (SAM) and cross-section scanning electron microscope (X-SEM) images taken across the bonded wafer pairs confirm the good direct bonding quality of the resulting interface. Daisy chains with up to 3200 copper to copper bonded pads and of about 50mOhm/pad, are shown to be connected successfully and its resistance value to match a target value, as well as to scale linearly with the increase of connections in the chain.
Modeling, Design, Fabrication, and Characterization of Ultra-high Bandwidth 3D Glass Photonic Substrates
Authors: Chou Bruce , Vis William , Furuya Ryuta , Sundaram Venky , Rao Tummala
Published: November 2015

This paper presents the modeling, design, fabrication, and characterization of ultra-low loss 3D optical waveguides integrated on a glass photonic substrate. A novel, single-step process was developed using moving mask lithography to fabricate a single mode optical waveguide with a built-in turning mirror capable of making 40° or 45° turns for vertical grating couplers or photodetectors, respectively. Planar alignment of the waveguide to fiber interfaces enable passive alignment, contributing to system cost reduction. An optical path with 1.1 dB loss from fiber to die was obtained from optical modeling, while the fabrication of single mode waveguides with built-in mirrors at <1° angular control was demonstrated.
Expanded Beam Fiber Optic Connectors Increase Optical Link Margin
Authors: Mazurowski John
Published: November 2015

Present fiber optic connections need to align two or more optical fibers to accuracies of microns (multimode fiber) and tenths of a micron (single more fiber). For connections in rugged applications, consisting of wide temperature ranges, substantial vibration, or in the presence of contaminants, the alignment of normal physical contact connections becomes even more difficult. New expanded beam connectors make fiber optic connections more durable, and help stabilize the transmission of high speed optical signals between systems, boxes, boards, and devices in these harsh environments.
A HIGH THROUGHPUT, LOW COST ASSEMBLY APPROACH FOR LED IMS PACKAGES TO HEAT SINK USING ADVANCED THERMAL INTERFACE MATERIALS
Authors: Bhattacharya Swapan K. , Xie Fei , Wu Han , Hodge Kelley , Pathammavong Keck , Houston Paul N. , Baldwin Daniel F. , Giorgini Albert
Published: November 2015

The objective of this study is to design and fabricate a high reliability LED Insulated Metal Substrate (IMS) package to complex heat sink attachment using an advanced thermal interface material (TIM). The assembly consists of LED IMS parts bonded to a heat spreader/sink using an advanced TIM and a corner bond material to quickly and accurately secure the LEDs in position. The corner bond adhesive is snap cured for fast machine cycle times while the high performance, high adhesion TIM materials cure throughout the rest of the assembly operation. This approach allows high accuracy LED bonding without the need for alignment pins or fasteners to anchor to the IMS. The IMS attached to the heat sink is then electrically interconnected with a thin flex substrate on top of the IMS. This approach is expected to replace the current mechanical fastners and low strength silicone TIM materials and reduce the cycle time and overall placement cost which are key drivers especially for the automotive industry.
Challenge to zero CTE and lower shrinkage organic substrate material for thin CSP package
Authors: Hashimoto Shintaro , Takanezawa Shin , Tsuchikawa Shinji , Takekoshi Masaaki , Oohashi Kenichi , Morita Koji
Published: November 2015

Along with the advancement in miniaturizing of mobile devices, typified by smart phones and tablet PCs, the semiconductor PKG substrate installed in these devices is demanded to be thinner and higher in density. As one of the most innovative solutions, the PoP (package on package) technology, which has the three-dimensional construction, has been expanding rapidly in recent years.

However, thinner PKG such as PoP tends to warp at the assembly process and cause the decrease in the connection reliability. Therefore ultra low CTE (coefficient of thermal expansion) core materials have been needed as a key solution for the reduction of the warpage for PoP.

We have already developed and mass-produced ultra low CTE core material named E-770G (CTE value: 1.8 ppm/°C) for this application. However, the demand for lower warpage is still stronger especially for thinner PKG applications. To meet this requirement, we confirmed that not only low CTE but also lower resin shrinkage control gives big impact to warpage.

In this paper, we would like to introduce new ultra low CTE and low shrinkage core material, named E-777G for next generation thin CSP. At the same time, we would like to explain the relationship between the warpage and material properties (CTE and resin shrinkage).

E-777G has ultra low CTE and low shrinkage. These properties were achieved by applying our original resin system designed by hard segments and soft segments. Hard segments have a stack structure of aromatic ring and the strong intermolecular force between them, which lead to the ultra low CTE and low shrinkage. Soft segments of low elastic modulus can follow approximately the thermal behavior of glass fabric when heated and cooled. Consequently, the material can show the ultra low CTE which is similar to that of glass fabric itself. As a result, E-777G has achieved the ultra low CTE of 0.7 ppm/°C by TMA method which leads to significant reduction of the warpage.

In the cooling process after the reflow, the bottom PKG of PoP shows a convex warpage. It is caused by resin shrinkage of substrate in the cooling process. As the method of decreasing resin shrinkage in the cooling process, we focused on decreasing free volume of the resin. By using molecular dynamics simulation, we designed the most suitable resin composition.

Confirming the warpage property, we evaluated the warpage behavior of the bottom PKG before/after assembly process. The bottom PKG using E-777G material showed lower warpage than E-770G. We confirmed that not only the ultra low CTE but also low shrinkage of material effectively contributes to the decrease of the warpage.
Highly conductive MWNT/silicone composite with low density MWNT bundles
Authors: Lee Sangeui , Cho Shinje , Kim Hajin , Han Intaek , Sohn Yoonchul
Published: November 2015

The MWNT/silicone composites were fabricated with two different kinds of MWNT bundles using mass production compatible three roll milling process. Density of MWNT bundles could be controlled by fabrication process of metal precursors. The difference of order of agglomeration of the MWNTs was turned out to be closely related with dispersion of the MWNTs in the composites. Though same composition of catalyst was used, catalyst powder made from gelation of the precursors followed by flame synthesis (FS) consisted of chunk-type particles, while that originated from spray of the precursor solution followed by thermal decomposition (STD) was composed of thin sheet-like particles. After CVD growth of MWNTs, the MWNT bundles were entangled to form large chunks for FS catalyst but they maintained with rod-like morphology for STD catalyst. Furthermore, individual bundle of STD-MWNTs also revealed lower density with more room inside the bundles, which resulted in the composite having higher electrical conductivity due to effective dispersion of STD-MWNTs in the composites. In this study, high electrical conductivity over 1,000 S/m was obtained with the composite of STD-MWNT/silicone. For the first time, direct correlation between morphology of CNT catalysts and physical property of CNT/polymer composite was demonstrated in an experimental manner.
Phase Change Material for Thermal Management in 3D Integrated Circuits Packaging
Authors: Li Mingli , Gong Na , Wang Jinhui , Lin Zhibin
Published: November 2015

Effective thermal control and management in three-dimensional electronic packaging are desirable to ensure the heat generated in integrated circuits can be dissipated. Conventional base materials in electronics from substrate to protective layers, due to low coefficient of thermal conductivity, cannot help to cool down the circuits, while such elevated temperature could highly impact the performance of the chips. In this study, phase change material (PCM) is selected for potential applications in thermal management of electronic packaging due to its isothermal nature and high thermal storage capability. PCM based composite is developed through the impregnation technology using highly porous expanded graphite. Heat transfer test results reveal that the PCM based composite displays superior heat storage capacity, while maintaining the favorable feature of thermal and chemical stabilization for electronic applications. Toward the end, the concept of implementation of PCM based composite is proposed in thermal control of 3D integrated circuits. It is expected the proposed composite will improve heat dissipation, and ultimately enhance the performance of the chips.
Low Temperature, Fast Sintering of Micro-Scale Silver Paste for Die Attach for 300°C Applications
Authors: Yu Fang , Johnson R. Wayne , Hamilton Michael C.
Published: November 2015

With an increasing demand for SiC and GaN high power devices that operate at high temperature, traditional solder materials are reaching their limitations in performance. In addition, there is a strong desire to eliminate high lead containing solders in Si power device packaging for use over conventional temperature range. Low temperature Ag sintering technology is a promising method for high performance lead-free die attachment. In a previous study, a pressureless sintering process and suitable metallization were demonstrated to provide high reliability die attach by using micro-size Ag sintering. The resulting die attach layer had approximately 30% porosity.

In this work, a low temperature pressure-assisted fast sintering process was examined. The porosity was decreased from 30% to 15% with application of a low pressure (7.6MPa) during a one minute sintering process. The shear strength for a 3 mm × 3 mm die was 70 MPa and the 8 mm × 8 mm die could not be sheared off due to a 100 kg shear module force limit. Both the Ag and Au metallization (die and substrate) were studied. Furthermore, a new substrate metallization combination was found that allows the use of Au thick film metallized substrates. High temperature (300 °C) storage tests for up to 2000 hours aging were conducted and results are presented.
Solder Paste Corrosivity Assesment: Bono Test
Authors: Puechagut Céline , Laügt Anne-Marie , Guéné Emmanuelle , Anisko Richard
Published: November 2015

Lead free soldering with no clean solder pastes represent nowadays the most common process in electronic assembly. A solder paste is usually considered as no-clean if it passes all IPC J-STD-004 corrosion tests: copper mirror, copper panel corrosion test, Surface Insulation Resistance (SIR) and Elecrochemical Migration (ECM). Other SIR and ECM tests are described in Bellcore GR-78-CORE and JIS Z3197 standards.

Although SIR and ECM tests are recognized by all standards authorities to evaluate the solder paste residue corrosivity after reflow, a more selective method, the Bono test, has been developed and implemented in some French companies as a qualification criterion. It has been proven that compared to common corrosion tests, the Bono test better differentiates the nature of solder paste residues.
Technique to predict reliability failure in side-gate transfer molded packages
Authors: Lakhera Nishant , Battle Tom , Chopin Sheila , Shantaram Sandeep , Singh Akhilesh K.
Published: November 2015

Scanning acoustic microscopy (SAM) is the primary method to non-destructively detect internal defects in finished semiconductor packages. SAM is heavily used to detect interfacial delamination in the die-package system. Though this method can achieve an acceptable resolution to analyze the quality of the package unit, it is not absolute in all cases. SAM is also time consuming and non-predictable, as it offers a latent response of the finished good to the reliability tests. This paper presents an analytical prediction method defined to gauge whether the epoxy mold compound (EMC) encapsulating a no polyimide (PI) die surface would yield detectable delamination at the die to mold compound interface in the package finished good. The new method can be used to gauge whether top of die to EMC delamination will occur with a change in new wire bond (WB) die layout, new EMC material and new mold process. This new method also provides a way to demonstrate that the observed delamination is not detrimental to package reliability. This method will demonstrate how the no-PI package reliability can be met to not cause electrical failures based on the resin rich (RR) volume.
C4 EM and CPI Reliability Benefits and Process Challenges of FBEOL Integration Changes Implemented in Lead-free C4 Products
Authors: Misra E. , Wassick T. , Melville I. , Tunga K. , Questad D. , Muzzy C. , Coffin J. , Carey C. , Mendelson R.
Published: November 2015

The introduction of low-k & ultra-low-k dielectrics, lead-free (Pb-free) solder interconnects or C4's, and organic flip-chip laminates for integrated circuits have led to some major reliability challenges for the semiconductor industry. These include C4 electromigration (EM) and mechanical failures induced with-in the Si chip due to chip-package interactions (CPI). In 32nm technology, certain novel design changes were evaluated in the last Cu wiring level and the Far Back End of Line levels (FBEOL) to strategically re-distribute the current more uniformly through the Pb-free C4 bumps and therefore improve the C4 EM capabilities of the technology. FBEOL process integration changes, such as increasing the thickness of the hard dielectric (SiNx & SiOx) and reducing the final via diameter, were also evaluated for reducing the mechanical stresses in the weaker BEOL levels and mitigating potential risks for mechanical failures within the Si chip. The supporting white-bump, C4 EM and electrical/mechanical modeling data that demonstrates the benefits of the design and integration changes will be discussed in detail in the paper. Some of the key processing and integration challenges observed due to the design and process updates and the corresponding mitigation steps taken will also be discussed.
Advanced lithography and electroplating approach to form high-aspect ratio copper pillars
Authors: Best Keith , McCleary Roger , Hollman Richard , Holmes Phillip
Published: November 2015

Advanced packaging technologies continue to enable the semiconductor industry to meet the needs for ever thinner, smaller and faster components required in mobile devices and other high performance applications.

In the early days of advanced packaging, C4 solder bumps were the alternative to wire bonding. Although lead-free solder remains one of the preferred methods for assembly, tall copper structures (copper pillars) are becoming the standard interconnect solution for many applications. A process of lithography and subsequent electroplating are the mainstream process for today's copper pillar formation on wafer level for high-end flip chip devices.

The latest trends in advanced packaging require another technology development when it comes to copper pillars. Modern integration schemes such as 2.5D interposer as well as 3D stacking have pushed the limits of standard lithography and copper electroplating capabilities. Specifically, the need for fine-pitch high aspect ratio copper pillars represents a challenge. In addition, the trend towards rectangular panel-based packaging as seen with glass interposers or panel fan-out (P-FO) devices demands a challenging scale-up of lithography and electroplating equipment and processing capabilities.

This work specifically focuses on the formation of high-aspect ratio copper pillars in excess of 100μm by means of stepper-based lithography followed by electroplating. A unique test vehicle has been created to evaluate the process latitude for lithography for different resist materials as well as the specific electroplating challenges associated with these tall and narrow structures. The paper investigates the influence of key parameters such as CD uniformity, pattern density variations and resist profile on the critically important pillar height uniformity across the wafer or panel. In addition, the resist profile behavior at the substrate interface is being examined as it influences undercut behavior during wet etch of the plating seed layer. A number of wet and dry-film resist materials and appropriate lithography processes (spin coat or laminate, expose, develop) followed by copper plating based on varying chemistries and process parameters are being explored.

The paper also summarizes the current requirements for the above mentioned lithography and plating processes as seen in the industry today.