Academic literature on the topic 'Growth of IMCs'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Growth of IMCs.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Growth of IMCs"
1
Gu, X., D. Yang, Y. C. Chan, and B. Y. Wu. "Effects of electromigration on the growth of intermetallic compounds in Cu/SnBi/Cu solder joints." Journal of Materials Research 23, no. 10 (2008): 2591–96. http://dx.doi.org/10.1557/jmr.2008.0331.
Full textAbstract:
In this study, the effects of electromigration (EM) on the growth of Cu–Sn intermetallic compounds (IMCs) in Cu/SnBi/Cu solder joints under 5 × 103 A/cm2 direct current stressing at 308, 328, and 348 K were investigated. For each Cu/SnBi/Cu solder joint under current stressing, the IMCs at the cathode side grew faster than that at the anode side. The growth of these IMCs at the anode side and the cathode side were enhanced by electric current. The growth of these IMCs at the cathode followed a parabolic growth law. The kinetics parameters of the growth of the IMCs were calculated from the thickness data of the IMCs at the cathode side at different ambient temperatures. The calculated intrinsic diffusivity (D0) of the Cu–Sn IMCs was 9.91 × 10−5 m2/s, and the activation energy of the growth of the total Cu–Sn IMC layer was 89.2 kJ/mol (0.92 eV).
2
Hang, Chunjin, Ruyu Tian, Liyou Zhao, and Yanhong Tian. "Influence of Interfacial Intermetallic Growth on the Mechanical Properties of Sn-37Pb Solder Joints under Extreme Temperature Thermal Shock." Applied Sciences 8, no. 11 (2018): 2056. http://dx.doi.org/10.3390/app8112056.
Full textAbstract:
Solder joints in thermally uncontrolled microelectronic assemblies have to be exposed to extreme temperature environments during deep space exploration. In this study, extreme temperature thermal shock test from −196 °C to 150 °C was performed on quad flat package (QFP) assembled with Sn-37Pb solder joints to investigate the evolution and growth behavior of interfacial intermetallic compounds (IMCs) and their effect on the pull strength and fracture behavior of Sn-37Pb solder joints under extreme temperature environment. Both the scallop-type (Cu, Ni)6Sn5 IMCs at the Cu lead side and the needle-type (Ni, Cu)3Sn4 IMCs at the Ni-P layer side changed to plane-type IMCs during extreme temperature thermal shock. A thin layer of Cu3Sn IMCs was formed between the Cu lead and (Cu, Ni)6Sn5 IMC layer after 150 cycles. The growth of the interfacial IMCs at the lead side and the Ni-P layer side was dominated by bulk diffusion and grain-boundary diffusion, respectively. The pull strength was reduced about 31.54% after 300 cycles. With increasing thermal shock cycles, the fracture mechanism changed from ductile fracture to mixed ductile–brittle fracture, which can be attributed to the thickening of the interfacial IMCs, and the stress concentration near the interface caused by interfacial IMC growth.
3
Lee, Chang Woo, Y. S. Shin, and J. H. Kim. "Precise Quantitative Evaluation of Nano-Ordered Intermetallic Compounds in Sn-3.0Ag-0.5Cu Lead-Free Solder Bump by Using TEM." Advanced Materials Research 47-50 (June 2008): 907–11. http://dx.doi.org/10.4028/www.scientific.net/amr.47-50.907.
Full textAbstract:
The growth behaviour of the intermetallic compounds (IMCs) in Pb-free solder bump is investigated. The Pb-free micro-bump, Sn-50%Bi, was fabricated by binary electroplating for flip-chip bond. The diameter of the bump is about 506m and the height is about 60 6m. In order to increase the reliability of the bonding, it is necessary to protect the growth of the IMCs in interface between Cu pad and the solder bump. For control of IMCs growth, SiC particles were distributed in the micro-solder bump during electroplating. The thickness of the IMCs in the interface was estimated by FE-SEM, EDS, XRF and TEM. From the results, The IMCs were found as Cu6Sn5 and Cu3Sn. The thickness of the IMCs decreases with increase the amount of SiC particles until 4 g/cm2. The one candidate of the reasons is that the SiC particles could decrease the area which be reacted between the solder and Cu layer. And another candidate is that the particle can make to difficult inter-diffusion within the interface.
4
Mohd Salleh, Mohd Arif Anuar, N. S. Ibrahim, N. Saud, et al. "Research Development of Solder Materials and its Intermetallic Compound (IMC) Study." Advanced Materials Research 626 (December 2012): 797–801. http://dx.doi.org/10.4028/www.scientific.net/amr.626.797.
Full textAbstract:
Nowadays, the formation and the subsequent growth of the intermetallic compounds (IMCs) and the development of new lead-free solder systems is a major issue in soldering. The excessive growth formation of intermetallic compounds will increase the brittleness of solder joints and detrimentally affects its mechanical properties. This paper reviews the latest fabrication method for solder materials and the literatures of bulk IMCs study in most solder materials by other researchers. Explanation on solder fabrication by using powder metallurgy method to produce solder materials and IMCs study were explained in detail in this paper.
5
Chen, Kuan-Jen, Fei-Yi Hung, Truan-Sheng Lui, and Wen-Yu Lin. "Effects of Static Heat and Dynamic Current on Al/Zn∙Cu/Sn Solder/Ag Interfaces of Sn Photovoltaic Al-Ribbon Modules." Materials 11, no. 9 (2018): 1642. http://dx.doi.org/10.3390/ma11091642.
Full textAbstract:
This present study applied Cu∙Zn/Al ribbon in place of a traditional Cu ribbon to a photovoltaic (PV) ribbon. A hot-dipped and an electroplated Sn PV ribbon reflowed onto an Ag electrode on a Si solar cell and estimated the feasibility of the tested module (Ag/Solder/Cu∙Zn/Al). After bias-aging, a bias-induced thermal diffusion and an electromigration promoted the growth of intermetallic compounds (IMCs) (Cu6Sn5, Ag3Sn). To simulate a photo-generated current in the series connection of solar cells, an electron with Ag-direction (electron flows from Ag to Al) and Al-direction (electron flows from Al to Ag) was passed through the Al/Zn∙Cu/Solder/Ag structure to clarify the growth mechanism of IMCs. An increase in resistance of the Ag-direction-biased module was higher than that of the Al-direction biased one due to the intense growth of Cu6Sn5 and Ag3Sn IMCs. The coated solder of the electroplated PV ribbon was less than that of the hot-dipped one, and thus decreased the growth reaction of IMCs and the cost of PV ribbon.
6
Said, Rita Mohd, Mohd Arif Anuar Mohd Salleh, Mohd Nazree Derman, Mohd Izrul Izwan Ramli, Norhayanti Mohd Nasir, and Norainiza Saud. "Isothermal Aging Affect to the Growth of Sn-Cu-Ni-1 wt.% TiO2 Composite Solder Paste." Key Engineering Materials 700 (July 2016): 123–31. http://dx.doi.org/10.4028/www.scientific.net/kem.700.123.
Full textAbstract:
This work investigated the effects of 1.0 wt. % TiO2 particles addition into Sn-Cu-Ni solder paste to the growth of the interfacial intermetallic compound (IMC) on Cu substrate after isothermal aging. Sn-Cu-Ni solder paste with TiO2 particles were mechanically mixed to fabricate the composite solder paste. The composite solder paste then reflowed in the reflow oven to form solder joint. The reflowed samples were then isothermally aged 75, 125 and 150 ° C for 24 and 240 h. It was found that the morphology of IMCs changed from scallop-shape to a more uniform planar shape in both Sn-Cu-Ni/Cu joints and Sn-Cu-Ni-TiO2 /Cu joint. Cu6Sn5 and Cu3Sn IMC were identified and grew after prolong aging time and temperature. The IMCs thickness and scallop diameter of composite solder paste were reduced and the growth of IMCs thickness after isothermal aging become slower as compared to unreinforced Sn-Cu-Ni solder paste. It is suggested that TiO2 particles have influenced the evolution and retarded the growth of interfacial IMCs.
7
Guo, Mengjiao, F. Sun, and Zuozhu Yin. "Microstructure evolution and growth behavior of Cu/SAC105/Cu joints soldered by thermo-compression bonding." Soldering & Surface Mount Technology 31, no. 4 (2019): 227–32. http://dx.doi.org/10.1108/ssmt-08-2018-0025.
Full textAbstract:
Purpose This paper used a novel technique, which is thermo-compression bonding, and Sn-1.0Ag-0.5Cu solder to form a full intermetallic compound (IMC) Cu3Sn joints (Cu/Cu3Sn/Cu joints). The purpose of the study is to form high-melting-point IMC joints for high-temperature power electronics applications. The study also investigated the effect of temperature gradient on the microstructure evolution and the growth behavior of IMCs. Design/methodology/approach In this paper, the thermo-compression bonding technique was used to form full Cu3Sn joints. Findings Experimental results indicated that full Cu/Cu3Sn/Cu solder joints with the thickness of about 5-6 µm are formed in a short time of 9.9 s and under a low pressure of 0.016 MPa at 450°C by thermo-compression bonding technique. During the bonding process, Cu6Sn5 grew with common scallop-like shape at Cu/SAC105 interfaces, which was followed by the growth of Cu3Sn with planar-like shape between Cu/Cu6Sn5 interfaces. Meanwhile, the morphology of Cu3Sn transformed from a planar-like shape to wave-like shape until full IMCs solder joints were eventually formed during thermo-compression bonding process. Asymmetrical growth behavior of the interfacial IMCs was also clearly observed at both ends of the Cu/SAC105 (Sn-1.0Ag-0.5Cu)/Cu solder joints. Detailed reasons for the asymmetrical growth behavior of the interfacial IMCs during thermo-compression bonding process are given. The compound of Ag element causes a reduction in Cu dissolution rate from the IMC into the solder solution at the hot end, inhibiting the growth of IMCs at the cold end. Originality/value This study used the thermo-compression bonding technique and Sn-1.0Ag-0.5Cu to form full Cu3Sn joints.
8
Xue, Peng, Jianzhi Tao, Peng He, Weimin Long, and Sujuan Zhong. "The Enhanced Mechanism of 0.05 wt. % Nd Addition on High Temperature Reliability of Sn-3.8Ag-0.7Cu/Cu Solder Joint." Applied Sciences 10, no. 24 (2020): 8935. http://dx.doi.org/10.3390/app10248935.
Full textAbstract:
In this study, the effect of appropriate Nd addition on improving the high-temperature reliability of Sn-3.8Ag-0.7Cu (SAC387)/Cu solder joint after aging treatment was investigated. The interfacial microstructure of solder joint was refined with proper addition of Nd. This phenomenon could be explained as the adsorbing-hindering effect of surface-active Nd atoms which blocked the growth of brittle intermetallic compounds (IMCs) in the solder joint. Theoretical analysis indicated that 0.05 wt. % addition of Nd could distinctly decrease the growth constant of Cu6Sn5 IMCs and slightly decrease the growth constant of Cu3Sn IMCs respectively. The shear force of SAC387-0.05Nd/Cu solder joint was evidently improved compared with the origin solder joint. In addition, SAC387-0.05Nd/Cu solder joint maintained excellent mechanical property compared with SAC387/Cu solder joint even after 1440 h aging treatment.
9
Hayashi, Yawara, Ikuo Shohji, Yusuke Nakata, and Tomihito Hashimoto. "Effect of Added Elements on Microstructures and Joint Strength of Lead-Free Sn-Based Solder Joint Dispersed IMC Pillar." Materials Science Forum 879 (November 2016): 2216–21. http://dx.doi.org/10.4028/www.scientific.net/msf.879.2216.
Full textAbstract:
To create a high reliability solder joint using IMCs dispersed in the joint, the joints with four types of lead-free solder were investigated. The joint with Sn-3.0Ag-0.7Cu-5.0In (mass%) has high die shear force compared to other joints investigated, and the joint with the Ni-electroplated Cu bonded at 300 oC for 30 min showed the maximum die shear force due to formation of a large number of fine IMCs. In the joint with Sn-0.7Cu-0.05Ni (mass%), uniform dispersion of a large number of IMCs was achieved, although the die shear force of the joint is lower than that of the joint with Sn-3.0Ag-0.7Cu-5.0In. In the joint with Sn-5.0Sb (mass%), a solder area was remained in the center of the joint although a large number of columnar IMCs form at the joint interface. The die shear force of the joint with Sn-5.0Sb increased with increasing the bonding time due to formation and growth of IMCs. In the joint with Sn-3.0Ag-0.5Cu (mass%), IMCs formed at the joint interface and did not disperse in the entire joint.
10
Chen, Jieshi, Yongzhi Zhang, Zhishui Yu, et al. "Interface Growth and Void Formation in Sn/Cu and Sn0.7Cu/Cu Systems." Applied Sciences 8, no. 12 (2018): 2703. http://dx.doi.org/10.3390/app8122703.
Full textAbstract:
In this work, the effects of electroplated Cu (EP Cu) and Cu addition (0.7%) in Sn solder on the intermetallic compounds (IMCs) growth and void formation were clarified by comparison with solder joints comprising of high purity Cu (HP Cu) substrate and pure Sn solder. After aging processes, a new IMC, Cu3Sn, was formed at the interface, in addition to Cu6Sn5 formed in the as-soldered joints. The EP Cu and Cu addition (0.7%) both had limited effects on the total IMCs thickness. However, the effects varied on the growth behaviors of different IMCs. Comparing to the void-free interface between Sn and HP Cu, a large number of voids were observed at the Cu3Sn/Cu interface in Sn/EP Cu joints. The formation of these voids may be induced by the impurities and fine grain, which were introduced during the electroplating process. The addition of Cu suppressed the inter-diffusion of Cu and Sn at the interface. Consequently, the growth of the Cu3Sn layer and formation of voids were suppressed.
Dissertations / Theses on the topic "Growth of IMCs"
1
Chen, Zhiwen. "Micro-mechanical characteristics and dimensional change of Cu-Sn interconnects due to growth of interfacial intermetallic compounds." Thesis, Loughborough University, 2015. https://dspace.lboro.ac.uk/2134/18431.
Full textAbstract:
Sn-based solder alloys are extensively used in electronic devices to form interconnects between different components to provide mechanical support and electrical path. The formation of a reliable solder interconnects fundamentally relies on the metallurgic reaction between the molten solder and solid pad metallization in reflowing. The resultant IMC layer at the solder/pad metallization interface can grow continuously during service or aging at an elevated temperature, uplifting the proportion of IMCs in the entire solder joint. However, the essential mechanical properties of interfacial IMC (i.e. Cu6Sn5, Cu3Sn) layers, such as Young s modulus and hardness, are drastically different in comparison with Sn-based solder and substrate. Therefore, the increasing fraction of interfacial IMCs in the solder joint can lead to significant deformation incompatibility under exterior load, which becomes an important reliability concern in the uses of solder joints for electronic interconnects. In the past decades, extensive research works were implemented and reported regarding the growth of interfacial IMC layers and its effect on the mechanical integrity of solder joints. But, the following fundamental issues in terms of mechanical and microstructural evolution in the uses of solder joints still remain unclear, demanding further research to elaborate: (1) The protrusion of IMCs: Though the growth of interfacial IMC layers along the diffusion direction in solder joints were studied extensively, the growth of IMCs perpendicular to the diffusion direction were reported in only a few papers without any further detailed investigation. This phenomena can crucially govern the long-term reliability of solder interconnects, in particular, in the applications that require a robust microstructural integrity from a solder joint. (2) Fracture behaviour of interfacial IMC layers: The fracture behaviour of interfacial IMC layers is a vital factor in determining the failure mechanism of solder joints, but this was scarcely investigated due to numerous challenges to enable a potential in-situ micro-scale tests. It is therefore highly imperative to carry out such study in order to reveal the fracture behaviour of interfacial IMC layers which can eventually provide better understanding of the influence of interfacial IMC layers on the mechanical integrity of solder joints. (3) Volume shrinkage: The volume shrinkage (or solder joint collapse) induced by the growth of interfacial IMC layers was frequently ascribed as one of the main causes of the degradation of mechanical reliability during aging due to the potentially resulted voids and residual stress at the solder/substrate interface. However, very few experimental works on the characterisation of such type of volume shrinkage can be found in literatures, primarily due to the difficulties of observing the small dimensional changes that can be encountered in the course of IMCs growth. (4) Residual stress: The residual stress within solder joints is another key factor that contributes to the failure of solder joints under external loads. However, the stress evolution in solder joints as aging progresses and the potential correlation between the residual stress and the growth of interfacial IMC layers is yet to be fully understood, as stress/strain status can fundamentally alter the course of total failure of a solder joint. (5) Crack initiation and propagation in solder joints: Modelling on the mechanical behaviour of solder joints is often undertaken primarily on the stress distribution within solder joints, for instance, under a given external loading. But there is lack of utilising numerical analysis to simulate the crack initiation and propagation within solder joints, thus the effect of interfacial IMC layers on the fracture behaviour of the solder joints can be elaborated in further details. In this thesis, the growth of interfacial IMCs in parallel and perpendicular to the interdiffusion direction in the Sn99Cu1/Cu solder joints after aging was investigated and followed by observation with SEM, with an intention of correlating the growth of IMCs along these two directions with aging durations based on the measured thickness of IMC layer and height of perpendicular IMCs. The mechanism of the protrusion of IMCs and the mutual effect between the growth of IMCs along these two directions was also discussed. The tensile fracture behaviour of interfacial Cu6Sn5 and Cu3Sn layers at the Sn99Cu1/Cu interface was characterised by implementing cantilever bending tests on micro Cu6Sn5 and Cu3Sn pillars prepared by focused ion beam (FIB). The fracture stress and strain were evaluated by finite element modelling using Abaqus. The tensile fracture mechanism of both Cu6Sn5 and Cu3Sn can then be proposed and discussed based on the observed fracture surface of the micro IMC pillars. The volume shrinkage of solder joints induced by the growth of interfacial IMC layers in parallel to the interdiffusion direction in solder joint was also studied by specifically designed specimens, to enable the collapse of the solder joint to be estimated by surface profiling with Zygo Newview after increased durations of aging. Finite element modelling was also carried out to understand the residual stress potentially induced due to the volume shrinkage. The volume shrinkage in solder joints is likely to be subjected to the constraint from both the attached solder and substrate, which can lead to the build-up of residual stress at the solder/Cu interface. Depth-controlled nanoindentation tests were therefore carried out in the Sn99Cu1 solder, interfacial Cu6Sn5 layer, Cu3Sn layer and Cu with Vickers indenter after aging. The residual stress was then evaluated in the correlation with aging durations, different interlayers and the locations in the solder joint. Finally, finite element models incorporated with factors that may contribute to the failure of solder joints, including microstructure of solder joints, residual stress and the fracture of interfacial IMC, were built using Abaqus to reveal the effect of these factors on the fracture behaviour of solder joints under applied load. The effect of growth of IMC layer during aging on the fracture behaviour was then discussed to provide a better understanding of the degradation of mechanical integrity of solder joints due to aging. The results from this thesis can facilitate the understanding of the influence of interfacial IMC layers on the mechanical behaviour of solder joints due to long-term exposure to high temperatures.
2
Cocetti, Monize. "Peso, altura, IMC e composição corporal de escolares de 07 a 17 anos no municipio de Campinas-SP." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/308307.
Full textAbstract:
Orientador: Antonio de Azevedo Barros Filho<br>Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas<br>Made available in DSpace on 2018-08-07T12:15:19Z (GMT). No. of bitstreams: 1
Cocetti_Monize_D.pdf: 4184206 bytes, checksum: 2c3d8f738ef8e44e22af1cab17355eca (MD5)
Previous issue date: 2006<br>Resumo: Este é um estudo transversal que teve como objetivo principal comparar peso, a altura, o Índice de massa corporal e a composição corporal de 6998 escolares, de 7 a 17 anos, matriculados em escolas públicas e particulares da rede de ensino do Município de Campinas, SP., além de avaliar a prevalência de sobrepeso e obesidade nos adolescentes. Foram realizadas medidas de peso, altura, circunferência do braço (CB), circunferência da cintura (CC), dobras cutâneas triciptal (DCT) e subescapular (DCSE) e aplicação do método de bioimpedância elétrica (BIA). As medidas derivadas foram índice de massa corporal (IMC), área muscular do braço (AMB), área de gordura do braço (AGB), % de gordura corporal (%GC), massa gorda (MG) e massa magra (MM). As variáveis foram agrupadas por idade, sexo e tipo de escola, e distribuídas em percentil. O IMC foi utilizado para avaliar sobrepeso (P=85) e obesidade (P=95), usando como referencial as curvas do Centers for Disease Control and Prevention (CDC, 2000). Foi verificado se existia diferença estatisticamente significante entre as variáveis em função da idade, sexo e tipo de escola. As medidas de altura, peso e IMC foram estatisticamente significantes, respectivamente, até os 16 anos, 15 anos e 14 anos, em função do tipo de escola, sendo maiores nas escolas particulares. Enquanto as medidas de %GC, MG, DCSE e AGB foram estatisticamente significantes, em todas as idades, em função do sexo e tipo de escola. A prevalência de sobrepeso foi de 11,1% e de obesidade foi de 5,6%. O sobrepeso e a obesidade foram maiores nas escolas particulares do que nas publicas, respectivamente, 14,5% vs 9,2% (p<0,01) e 7,9% vs 4,4% (p<0,01), e nos meninos do que nas meninas, respectivamente, 12,3% vs 10,2 (p<0,01) e 8,3% vs 3,7% (p<0,01). Os escolares deste estudo atingem peso, altura e IMC semelhantes ao final da adolescência, porém com diferenças significativas na composição corporal, com maior prevalência de obesidade e percentual de gordura corporal entre as crianças e adolescentes das escolas particulares do que nas públicas.<br>Abstract: The main purpose of this cross sectional study was to evaluate the body composition and growth of 6,998 children and adolescents aged between 07 and 17 years, enrolled at public and private schools in the city of Campinas, 8ao Paulo. In addition to assessment of overweight and obesity prevalence in the adolescents. Measurements were also taken of weight, height, arm circumference (AC), waist circumference (WC), triceps skinfold thickness (TSFT), subscapular skinfold thickness (SSFT) and bioelectrical impedance (BI). The derived measures were body mass index (BMI), arm muscle area (AMA), arm fat area (AFA), body fat percent (%BF), lean body mass (LM) and fat mass (FM). The variables were grouped according to age, sex and type of school and then transformed into percentiles. The BMI was used to evaluate overweight (p=85) and obesity (p=95) using the CDC (2000) as reference. The existence of a statistically significant difference in growth assessment measures in relation to age, sex and type of school was verified. Among the adolescents, weight, height and BMI were statistically significant in relation to sex and type of school. Measures of %BF; FM, 88FT and AMA were statistically significant for all ages in relation to sex and type of school. Overweight prevalence was 11.1 % and obesity was 5.6%. Both overweight and obesity were higher in private schools than in public schools respectively, overweight 14,5 vs 9,2 (p<0.0l) and obesity 7,9 vs 4,4 (p<0.01) and boys than girls, respectively, 14,5 vs 9.2 (p<0.0l) and 7,9 vs 4,4 (p<0.01). The schoolchildren in this study reach weight, height and BMI of similar values at the end of puberty, but with different results related to the body composition, with higher prevalence of obesity and percent of fat among schoolchildren of private schools than public schools.<br>Doutorado<br>Saude da Criança e do Adolescente<br>Doutor em Saude da Criança e do Adolescente
3
Faizan, Mohammad. "EXPERIMENTAL STUDY AND MODELING OF METAL DISSOLUTION AND INTERMETALLIC COMPOUND GROWTH DURING SOLDERING." University of Akron / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=akron1195178338.
Full text
4
Jacota, Madalina. "Variations pondérales pré-conceptionelles et gestationnelles : étude de leurs relations avec le diabète gestationnel et le développement de l’adiposité des enfants à 5-6 ans à partir des cohortes mère-enfant françaises EDEN et ELFE." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS329.
Full textAbstract:
Contexte. La corpulence de la mère au moment de la conception et son évolution pondérale pendant la grossesse ont été mises en relation dans de nombreuses études avec le poids de naissance de l’enfant et sa croissance postnatale, ainsi qu’avec le risque ultérieur d’obésité et d’anomalies métaboliques de la mère et de l’enfant. Néanmoins, peu d’études se sont intéressées à la trajectoire pondérale de la mère avant grossesse et à son lien avec le déroulement de la grossesse et avec la croissance et l’adiposité des enfants.Objectif : Etudier les relations entre différents paramètres de l’histoire pondérale de la mère avant et pendant la grossesse et leurs liens avec le risque de diabète gestationnel et la corpulence des enfants.Populations. Nous avons utilisé les données de deux cohortes mère-enfant françaises : ELFE et EDEN. L’étude Elfe (Etude longitudinale française depuis l’enfance) a inclus 18329 nouveau-nés dans un échantillon aléatoire de 344 maternités en 2011 en France métropolitaine. La cohorte EDEN (l’Étude des Déterminants pré- et postnatals du développement et de la santé de l’Enfant) a recruté 2002 femmes enceintes dans les maternités de Nancy et Poitiers entre 2003 et 2006. Dans les deux cohortes nous avons utilisé des données du dossier obstétrical et des questionnaires remplis par les parents. Dans la cohorte EDEN nous disposions également des données des examens cliniques des femmes pendant la grossesse et en post-partum, du nouveau-né et de l’enfant à 5-6 ans, incluant l’estimation de la composition corporelle par impédancemétrie des enfants à 5-6 ans.Résultats. Dans la cohorte Elfe, un régime avant grossesse, une perte ou un gain de poids important avant grossesse étaient associés à un gain de poids pendant la grossesse plus important, indépendamment de l’IMC pré-conceptionnel et du statut socio-économique. L’association positive entre la perte pondérale avant grossesse et la prise de poids gestationnelle était plus marquée chez les femmes obèses en début de grossesse ou ayant suivi un régime avant la grossesse. Les femmes ayant pris beaucoup de poids dans l’année avant grossesse présentaient un risque plus élevé de diabète gestationnel, indépendamment de la corpulence atteinte à la conception.Dans la cohorte EDEN, l’IMC maternel pré-conceptionnel était positivement associé à l’IMC, au pourcentage de masse grasse et à une distribution plus défavorable de l’adiposité (tronculaire, viscérale) des enfants à 5-6 ans. Ces associations étaient observées indépendamment de la prise de poids pendant la grossesse et du statut socio-économique des femmes. Une analyse fine de la forme des relations a permis de souligner l’existence de liens essentiellement aux deux extrémités de la corpulence maternelle. Après ajustement sur l’IMC pré-conceptionnel, le gain pondéral gestationnel était positivement associé au Z-score d’IMC des enfants à 5-6 ans, surtout chez les femmes maigres avant grossesse. Un ajustement supplémentaire sur le poids de naissance des enfants a diminué la force des associations entre le Z-score d’IMC des enfants et l’IMC maternel ou la prise de poids pendant la grossesse, mais les deux associations restaient significatives.Conclusion. Une perte de poids avant grossesse, surtout si elle est intentionnelle, semble engendrer une augmentation compensatoire du gain de poids pendant la grossesse. La prise de poids importante avant grossesse, au-delà de la corpulence maternelle en début de grossesse, pourrait être considérée comme un facteur de risque indépendant de diabète gestationnel. A l’âge de 5-6 ans, l’effet rémanent de l’environnement nutritionnel intra-utérin sur l’adiposité des enfants n’est détecté que chez les femmes maigres ou très obèses avant grossesse. D’autres études chez l’enfant sont nécessaires pour pouvoir conclure sur des recommandations de perte de poids avant grossesse chez les femmes en surpoids et obèses<br>Context. Maternal BMI at conception and weight gain during pregnancy were related in numerous studies with offspring’s birth weight and postnatal growth, as well as with mothers’ and children’s obesity and metabolic risk later on. Nevertheless, few studies addressed the weight trajectory of the mother before pregnancy and its association with children’s growth and adiposity.Objective: To study the associations between different parameters of maternal weight history before and during pregnancy and their relations with the risk of gestational diabetes and with children’s BMI and adiposity.Populations. We used data from two French mother-child cohorts: ELFE and EDEN. The ELFE study (Etude longitudinale française depuis l’enfance) included 18329 newborns in a random sample of 344 maternity wards in 2011 in mainland France. The EDEN cohort (study of pre- and early postnatal determinants of child development and health) recruited 2002 pregnant women in the maternity wards of Nancy and Poitiers between 2003 and 2006. We used data from obstetric files and from questionnaires filled-in by parents in both cohorts. In addition, the EDEN cohort had data from clinical examinations (of mothers during pregnancy and after delivery and of children at birth and at 5-6 years of age), including the estimation of children’s body composition by bio-impedancemetry at 5-6 years.Results. In the ELFE study, either maternal dieting to lose weight or an important weight gain or loss in the year before pregnancy were associated with a higher weight gain during pregnancy, independently of maternal pre-pregnancy BMI and socioeconomic status. The positive association between weight loss before pregnancy and weight gain during pregnancy was stronger in women who were obese or who had reported weight-reducing diets before pregnancy. Women who had gained an important amount of weight in the year before pregnancy had a higher risk of gestational diabetes, independently of the BMI reached at the beginning of pregnancy.Our analyses on the EDEN cohort showed that maternal pre-pregnancy BMI was positively related with children’s BMI, fat mass percent and central adiposity at 5-6 years of age. These associations were observed independently of women’s weight gain during pregnancy and socioeconomic status. A more thorough analysis of the shape of these relations showed associations essentially at the extremities of the maternal BMI range. Gestational weight gain was positively associated with children’s BMI Z-score at 5-6 years, after adjustment for maternal pre-pregnancy BMI, especially in women who were thin before pregnancy. Additional adjustment for children’s birth weight decreased the force of associations between children’s BMI Z-score and both maternal pre-pregnancy BMI and gestational weight gain, but both associations remained statistically significant.Conclusion. Important weight loss before pregnancy, especially if intentional, seems to enhance a compensatory increase in gestational weight gain. Important weight gain before pregnancy, beyond its role in maternal BMI reached before pregnancy, might be considered as an independent risk factor of gestational diabetes. At 5-6 years, the persistent effect of the intra-uterine environment on children’s BMI and adiposity is only detected in women who were thin or severely obese before pregnancy. Additional studies on children are necessary in order to conclude on weight loss recommendations before pregnancy in overweight and obese women
5
Costi, Roberta Burkhardt. "Mulheres idosas participantes de um programa de exercícios-analisando o consumo alimentar e o índice de massa corporal (IMC) em relação ao desempenho no teste de caminhada de seus minutos." Master's thesis, Instituições portuguesas -- UP-Universidade do Porto -- -Faculdade de Ciências do Desporto e de Educação Física, 2001. http://dited.bn.pt:80/29550.
Full text
6
Mazzeti, Camila Medeiros da Silva. "A relação alométrica ou isométrica nos índices de massa corporal entre menores de 20 anos." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/6/6138/tde-10102018-085303/.
Full textAbstract:
Objetivos: Analisar o ajuste alométrico para MC e altura entre indivíduos menores de 20 anos. Métodos: Dados de indivíduos de 0-20 anos de National Health and Nutrition Examination Survey (NHANES-1999-2013); Pesquisa Nacional de Saúde e Nutrição (PNSN-1989); Encuesta de Salud y Nutrición (2012); England Health Survei (2005-2014) e; Korean National Health and Nutrition Examination Survey (KNHANES-1998-2014). MC e de altura foram convertidos à escala logarítmica e modelados por regressão linear em 24 grupos etários, 2 sexos e os 5 países. O β dessa regressão deu origem ao p valor que foi estimado em 2 etapas. 1) Todos os dados disponíveis nos inquéritos, excluíndo apenas os valores biologicamente implausíveis; e 2) O p foi calculado após a exclusão dos valores não esperados para idade (VNEI) de MC e altura. VNEI foi definido como casos ±2,0 DP(z) do resíduo da regressão de MC pela idade, altura pela idade e MC pela altura. Em seguida, os valores p definidos no pool de dados foram modelados por spline com 5 knots, para definição de um p internacional (ip). Após calculou-se o IA - Indice Alométrico para todos os individuos. Para análise da correlação entre os índices e a massa adiposa foram utilizadas medidas de Densiotometria (DXA), Impedância Bioelétrica (BIA), Circunferência de Cintura (CC) e Dobras Cutâneas (DC). As correlações com os indices foram estimada pelo coeficiente de Pearson(r). Em uma análise de efeitos mistos, estimou-se o coeficiente correlção intraclasses (CCI), entre os diferentes países e as diferentes fenótipos humanos para altura, MC, IMC e IA. Resultados: A exclusão de VNEI (8,5% da amostra) diminuiu a diferença do p entre os países. O p e o ip apresentoram valores próximos a 2 ao nascimento, aumentou para 3 a 3,5 (7 e 11 anos nas meninas e 8 a 12 nos meninos) e regrediu a 2 no final do crescimento. O IA apresentou r próximo de zero em relação a altura contra r proximos de 0,4 para o IMC durante a puberdade. A correlação da massa adiposa para os dois indices foi semelhante, sempre apresentando r acima de 0,85 para todas as formas de análise via DC, BIA, CC e DXA. IA apresentou menor correlação com massa muscular e densidade óssea. O CCI foi maior entre os paises e praticamente nulo entre as fenótipos humanos. A maior variação entre os paises ficou a cargo da altura, seguido da massa corporal e IMC. O IA foi a medida que se apresentou com menor variação entre os paises (3,6%) e entre fenótipos humanos (1,7%). Conclusões: A exclusão VNEI contribuiu para diminuir o efeito do estado nutricional sobre a alometria para se estimar o p valor. O ip mostrou-se uma valor promissor para uso internacional. O IA no conjunto de evidências apresenta uma vantagem em relação ao IMC, uma vez que tem correlção 0 com a altura, e uma correlação equivalente ao IMC com a massa adiposa além de apresentar o menor CCI entre fenótipos humanos e nacionalidades. A maior variação do CCI ficou a cargo do país em relação a altura, justificado pelos difentes contextos epidemiológicos.<br>Objectives: To analyze the allometric scalling for BM and the height under 20 years old. Methods: Individuals 0-20 years of the National Health and Nutrition Examination Survey (NHANES-1999-2013); Pesquisa Nacional de Saúde e Nutrição (PNSN-1989); Encuesta de Salud y Nutrición (2012); England Health Survei (2005-2014) and; Korean National Health and Nutrition Examination Survey (KNHANES-1998-2014). BM and height were converted to logarithmic scale and modeled by linear regression, in 24 age groups, 2 sexes and 5 countries. The β of this regression gave the estimated p value in 2 steps. 1) All data available in the surveys, excluding only those biologically implausible values; and 2) The value was obtained after the exclusion of values not expected for age (VNEA) of MC and height. VNEA was defined as ± 2.0 SD (z) cases of regression of BM by age, height by age and MC by height. Then, the values were modeled by spline in 5 knots, to define an international (ip). After were calculated the AI - Allometric Index for all individuals. The Pearson correlation (r) between the indices and the fat mass was calculated used data dorm densitometry (DXA), Bioelectrical Impedance (BIA), Waist Circumference (WC) and Skin Folds (SF). In an analysis of mixed effects, was estimated the intraclass correlation coefficient (ICC), between countries and ethnicities for different dimensions for BM, BMI and AI. Results: Exclusion of VNEA (8.5% of the sample) decreased the difference between countries. The p and ip presented values close to 2 at birth, increased to 3 to 3.5 (7 and 11 years in girls and 8 to 12 in boys) and recorded 2 at the end of growth. AI was close to zero in correlation with height and for BMI was r= 0.4 during puberty. The correlation of the adipose mass for the two indices was similar, always presenting r above 0.85 for all forms of analysis via DC, BIA, CC and DXA. AI presented a lower correlation with muscle mass and bone density. ICC is larger among countries and is practically zero among ethnicities. The greatest difference between the groups was the height, the BM and the BMI. AI showed the smallest difference between the countries (3.6%) and between the ethnic groups (1.7%). Conclusions: A VNEA exclusion contributed to decrease the effect of nutritional status on allometry to estimate the p value. The value ip has proved to be a promising value for international use. The IA in the body of evidence has an advantage over BMI, since it has correlation 0 with height, and a correlation equivalent to the BMI with the adipose mass besides presenting the lowest CCI between ethnicities and nationalities. The greatest variation of ICC was borne by the country in relation to height, justified by the different epidemiological contexts.
7
Rincón, Laura Jackeline García. "Associação entre o peso ao nascer, o estado nutricional e o crescimento transversal do maxilar: implicações para a saúde materna e infantil." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/6/6143/tde-08012018-132657/.
Full textAbstract:
O crescimento é um processo dinâmico que muda ao longo da vida. O crescimento ósseo é um evento multicausal no qual, além dos fatores biológicos, intervêm outras características como as relacionadas ao nível socioeconômico, à raça, ao período perinatal, aos hábitos, entre outros. Este estudo objetivou identificar fatores associados ao crescimento transversal do osso maxilar representado pela medida da distância intermolar superior. Foi realizado um estudo seccional aninhado numa coorte, com uma amostra de 158 crianças entre 7 e 9 anos de idade das escolas urbanas de Acrelândia, município da Amazônia Ocidental Brasileira. A variável dependente foi a distância intermolar superior, medida entre as fossas centrais dos primeiros molares superiores permanentes. A partir da idade da introdução da mamadeira foi desenvolvida uma escala assumindo valores de 1 a 10. O sexo, o peso ao nascer, o padrão de uso da mamadeira e o escore Z do índice de massa corporal (IMC) para a idade foram consideradas como variáveis independentes, sendo analisadas por meio de modelo de equações estruturais (MEE). Foram encontrados efeitos diretos positivos significativos do sexo (CP=0,203; p=0,007), peso ao nascer (CP=0,155; p=0,046) e escore Z do IMC para a idade (CP=0,165; p=0,030) sobre o crescimento transversal do maxilar. Os efeitos indiretos (CP=0,058; p=0,029) e o efeito total (CP=0,262; p=0,000) do sexo sobre o desfecho mostraram significância estatística. Os efeitos indiretos do peso ao nascer sobre o desfecho não foram significativos (CP=0,018; p=0,508), porém, o efeito total foi significativo (CP=0,174; p=0,023). Em conclusão, o sexo, o peso ao nascer, a idade de introdução da mamadeira e o escore Z do IMC para a idade associam-se ao crescimento transversal do osso maxilar. Além de contribuir para um adequado peso ao nascer da criança, políticas e programas que favoreçam o cuidado pré natal e condições para garantir um parto a termo podem repercutir positivamente no crescimento transversal do maxilar. Do ponto de vista da Vigilância em Saúde, crianças com peso ao nascer diminuído, padrão inadequado de aleitamento materno e déficit nutricional para a idade podem apresentar maior probabilidade de desenvolver atrofia dos maxilares podendo, conforme a gravidade, redundar numa oclusopatia com importante impacto na qualidade de vida<br>Growth is a dynamic process that changes throughout life. Bone growth is a multicausal event in which other characteristics such as socioeconomic level, race, perinatal period, habits, and others are involved in addition to biological factors. This study aimed to identify with the associated factors transverse growth of the maxillary bone represented by the superior intermolar distance. A cross-sectional survey nested in a population-based cohort study was conducted with a sample of 158 children aged 7 to 9 years old from the urban schools of Acrelandia, a small town in the Brazilian Western Amazon. The dependent variable was the upper intermolar distance measured between the central fossae of the first permanent maxillary molars. From the age of bottle introduction, a scale was developed assuming values from 1 to 10. Sex, birth weight, bottle introduction scale and Z score of body mass index (BMI) for age (BAZ) were considered as independent variables, being analyzed with structural equations model (SEM). Significant direct positive effects of sex (CP=0,203; p=0,007), birth weight (CP=0,155; p=0,046) and BAZ (CP=0,165; p=0,030) on transverse maxillary growth were found. The indirect effects (CP=0,058; p=0,029) and the total effect (CP=0,262; p=0,000) of sex on the outcome were statistically significant. The indirect effects of birth weight on outcome were not significant (CP=0,018; p=0,508), however, the total effect was significant (CP=0,174; p=0,023). In conclusion, sex, birth weight, bottle beginning age and BMI Z score for age showed association with the transverse growth of the maxillary bone. In addition to contributing to an adequate birth weight of the child, policies and programs that favor prenatal care and conditions to guarantee a full-term birth can positively affect transversal growth of the maxilla. From a Health Surveillance point of view, children with reduced birth weight, inadequate breastfeeding pattern and nutritional deficit for age may be more likely to develop atrophy of the jaws which, depending on the severity, may result in malocclusion with an important impact on quality of life
8
Hsu, Feng-Chih, and 許豐智. "Mechanical Behavior of Thin Film: IMC Growth, Internal Friction, Stress and Scale Effects." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/06978719181658910853.
Full textAbstract:
博士<br>國立中興大學<br>精密工程學系所<br>102<br>This study presents the results of four-point bending tests investigating the effects of substrate strain on the growth of interfacial Cu-Sn inter-metallic compounds (IMCs). Test specimens were cut into strips, 27 mm in length and 5 mm in width, from 4 inch double polished silicon wafers. A very thin adhesion layer (Ta) was deposited on the silicon substrate by sputtering followed by a 10 μm thick layer of copper using electroplating. Finally, a 30 μm tin layer was deposited over the copper film also by electroplating. Samples were then placed in a furnace at 200 ℃ to undergo bending in order to introduce in-plane strain under tension or compression. Control samples also underwent the same treatment without applied strain. Our aim was to investigate the influence of substrate strain and aging time on the formation of IMCs (1.54 x 10-4, 2.3 x 10-4 and 3.46 x 10-4). The thickness and separation of each phase (Cu3Sn) and (Cu6Sn5) are clearly visible in scanning electron microscope images. Compressive strain and tensile strain both increased the thickness of the IMC layer during the aging process; however, the effects of compressive strain were more pronounced than those of tensile strain. We hypothesize that the increase in IMC thickness is related to the strain enhanced out-diffusion of Cu towards the solder as well as strain in the underlying lattice at the diffusion interface.
We also investigate the internal friction in nanocrystalline silver and gold thin films (40 – 170 nm thick) deposited on silicon substrate. Paddle-like samples were designed to present uniform stress and all measurements were performed under high vacuum to eliminate the effects of air damping. Annealed thin films presented far less internal friction than as-deposited films. Annealing reduced the internal friction in Ag films by 3 – 28 times lower than those obtained from as-deposited films. Annealing reduced internal friction in Au films to 17 %, 29 %, and 42 % in 41 nm, 90 nm, and 170 nm samples, respectively. With the exception of the thinnest Au film, the internal friction in all thin metal films was dependent on film thickness. In all cases, internal friction was affected by grain size and grain boundary.
9
Chang, Kuo-Chin, and 張國欽. "Study of Effects of Cu Stud Design and IMC Growth on the Reliability of Micro-Electronic Devices." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/26869483800426382279.
Full textAbstract:
博士<br>國立清華大學<br>動力機械工程學系<br>91<br>A wafer level package (WLP) without the underfill layer was introduced in recent years to address the demand of the electronic packaging industry for increased density and performance, as well as lightness, thinness, small size and cost-effectiveness. However, the solder joint reliability under thermal cycling conditions becomes a critical problem when mounting the WLP onto a PCB when the underfill layer has been eliminated. Consequently, enhancing the board level reliability is of primary concern in current WLP design. At the same time, the solder ball shear test has been widely adopted in the electronics industry to estimate the strength of solder ball attachment of advanced electronic packages. A solder ball with low shear strength is usually considered a weak solder joint in package reliability testing. Consequently, demands for increasing the solder ball shear strength have risen in recent years.
In order to solve these problems, this research proposed a new WLP design, based on forming a Cu stud on the center of the surface of the solder pad. The solder pad with a round Cu stud was made using a semiconductor manufacturing process. Therefore, this novel Cu stud design technology is workable. To investigate the impact of a Cu stud on the solder ball shear strength and solder joint reliability, 3-D non-linear finite element models were used for the Cu stud design. In shear analysis, this investigation explored the effects of various parameters including the Cu stud’s dimension, shape, and material properties on the solder ball shear strength. Furthermore, the shear force-displacement curves, obtained by computational analysis, were compared with the experimental results to demonstrate the accuracy of the finite element models. In thermal cycling analysis, this research investigated the effects of various parameters, including the Cu stud’s dimension, shape, material properties and the die and PCB thicknesses on the solder joint’s reliability. To demonstrate the accuracy of the finite element models, the analytical results were compared with the experimental results and the experimental data reported in the literature.
Comparing the experimental data with the results from the finite element analysis revealed that the finite element analysis was reliable. The analytical results established that a suitable size of Cu stud in a solder ball could effectively enhance the ball’s shear strength. Moreover, the solder joint reliability could be significantly improved by forming large Cu studs on the surfaces of the solder pads of WLP and PCB substrate, and could be further enhanced by combining large Cu studs with thin die.
In addition, this research also explored the growth of intermetallic compounds (IMC) under aging for eutectic Sn-Pb solder reflowed on a Cu pad with an Au/Ni surface finish. The effects of the intermetallic layer on the solder ball shear strength were examined for various solder ball sizes, Cu pad sizes and Au layer thicknesses. The IMC growth is dominated by the diffusion-controlled mechanism, in which the vacancy diffusion is the main diffusion mode. The vacancies and atoms can interchange locations continuously. Experimental results indicated that the degradation of the solder ball shear strength was found to be mainly caused by brittle interfacial fracture, due to the formation and growth of the Au0.5Ni0.5Sn4 intermetallic layer. Decreasing the Au layer thickness can reduce the Au weight in the solder and the Au0.5Ni0.5Sn4 thickness, and so avoid the degradation of the solder ball shear strength.
The findings of this research can offer designers and manufacturers an index to adjust the design for advanced ball grid array package to enhance their package reliability.
10
Hao-WenHsueh and 薛皓文. "On the Kinetics and Mechanism of IMC Growth and Electrified Tensile Intergranular Fracture of Fine Silver Alloy Wires." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/j999mp.
Full textAbstract:
博士<br>國立成功大學<br>材料科學及工程學系<br>105<br>The growth kinetics of intermetallic compound (IMC) of the Ag alloy wires and Al Pad was discussed, and the damage of excessive current density were investigated by electrified test and the dynamic current tensile (DCT) test.
Observations on the Ag-8Au-3Pd wires after high temperature storage (HTS) test indicated that the main IMC between Ag alloy wires and Al Pads were Ag2Al (hexagonal), and the main diffused routes were Ag and Al diffusing into each other. Because a Pd-rich phase as a diffusing barrier of Al was existed in the 200 nm thin layer at the top of the IMC, and the Kirkendall voids appeared upper the IMC.
The effects of excessive current density on the Ag-8Au-3Pd wires were investigated by electrified test. The grain boundary were reduced and the electrical resistance were decreased by joule’s heat, and the bamboo grains were formed gradually in current stressing.
The DCT test were employed to measure the tensile properties during current stressing. Both the elongation and tensile strength of the wires decreased in the DCT test, particularly the Ag-based wires. The voids and cracks were generated by electromigration and were propagated by strain applied. Therefore, the weakened grain boundary was the main cause of intergranular fracture of the Ag-based wires.
Overall, compared to the Cu-based wires, electromigration occurred more easily in the Ag-based wires; therefore, the relationship in electrical current and the change in materials should be noticed to avoid the failures happened.
Book chapters on the topic "Growth of IMCs"
1
Artan, N. Sertac, and Reza K. Amineh. "Wireless Power Transfer to Implantable Medical Devices With Multi-Layer Planar Spiral Coils." In Emerging Capabilities and Applications of Wireless Power Transfer. IGI Global, 2019. http://dx.doi.org/10.4018/978-1-5225-5870-5.ch009.
Full textAbstract:
Implantable medical devices such as pacemakers, implantable cardioverter defibrillators, deep brain stimulators, retinal and cochlear implants are gaining significant attraction and growth due to their capability to monitor the health condition in real time, diagnose a particular disease, or provide treatment for a particular disease. In order to charge these devices, wireless power transfer technology is considered as a powerful means. This eliminates the need for extra surgery to replace the battery. In this chapter, some of the major implanted medical devices are reviewed. Then, various wireless power transfer configurations are reviewed briefly for charging such devices. The chapter continues with reviewing wireless power transfer configurations based on the multi-layer printed or non-printed planar spiral coils. At the end, some of the recent works related to using multi-layer planar spiral coils for safe and efficient powering of IMDs will be discussed.
2
Artan, N. Sertac, and Reza K. Amineh. "Wireless Power Transfer to Implantable Medical Devices With Multi-Layer Planar Spiral Coils." In Research Anthology on Emerging Technologies and Ethical Implications in Human Enhancement. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-8050-9.ch023.
Full textAbstract:
Implantable medical devices such as pacemakers, implantable cardioverter defibrillators, deep brain stimulators, retinal and cochlear implants are gaining significant attraction and growth due to their capability to monitor the health condition in real time, diagnose a particular disease, or provide treatment for a particular disease. In order to charge these devices, wireless power transfer technology is considered as a powerful means. This eliminates the need for extra surgery to replace the battery. In this chapter, some of the major implanted medical devices are reviewed. Then, various wireless power transfer configurations are reviewed briefly for charging such devices. The chapter continues with reviewing wireless power transfer configurations based on the multi-layer printed or non-printed planar spiral coils. At the end, some of the recent works related to using multi-layer planar spiral coils for safe and efficient powering of IMDs will be discussed.
3
Okazaki, Shintaro. "Short Message Service (SMS) as an Advertising Medium." In Multimedia Technologies. IGI Global, 2008. http://dx.doi.org/10.4018/978-1-59904-953-3.ch092.
Full textAbstract:
The proliferation of the Internet-enabled mobile device has extended into many parts of the world. Collectively, the mobile-network operators paid more than $100 billion for licenses to operate “third-generation” (3G) networks, which were among “the largest bet in business history on the introduction of a new technology” (Economist, 2005). This drastic move has been most illustrated by the use of short message service (SMS) and multimedia messaging service (MMS) by mobile users. For example, a recent survey indicates that SMS in the Asia-Pacific region will increase to up to 75% of mobile subscribers in 2006 (IDC Asia/Pacific, 2003). As a result, marketers and agencies are increasingly interested in taking advantage of this growth, by incorporating SMS advertising as part of an integrated marketing communications (IMC) strategy. However, there has been little academic research on mobile advertising, perhaps because its growth is still in an early stage and the technological infrastructure varies across markets. The study has two objectives: (1) to identify the factors influencing MNCs’ managerial intention to adopt SMS advertising, and (2) to test a statistical relationship between these factors and managerial intention to use SMS advertising. To this end, we conducted telephone interviews of senior executives of MNCs operating in European markets.
4
Okazaki, S. "Short Message Service (SMS) as an Advertising Medium." In Encyclopedia of Mobile Computing and Commerce. IGI Global, 2007. http://dx.doi.org/10.4018/978-1-59904-002-8.ch148.
Full textAbstract:
The proliferation of the Internet-enabled mobile device has extended into many parts of the world. Collectively, the mobile-network operators paid more than $100 billion for licenses to operate “third-generation” (3G) networks, which were among “the largest bet in business history on the introduction of a new technology” (Economist, 2005). This drastic move has been most illustrated by the use of short message service (SMS) and multimedia messaging service (MMS) by mobile users. For example, a recent survey indicates that SMS in the Asia-Pacific region will increase to up to 75% of mobile subscribers in 2006 (IDC Asia/Pacific, 2003). As a result, marketers and agencies are increasingly interested in taking advantage of this growth, by incorporating SMS advertising as part of an integrated marketing communications (IMC) strategy. However, there has been little academic research on mobile advertising, perhaps because its growth is still in an early stage and the technological infrastructure varies across markets. The study has two objectives: (1) to identify the factors influencing MNCs’ managerial intention to adopt SMS advertising, and (2) to test a statistical relationship between these factors and managerial intention to use SMS advertising. To this end, we conducted telephone interviews of senior executives of MNCs operating in European markets.
5
Galanis, Nikolas, Enric Mayol, María José Casany, and Marc Alier. "Tools Interoperability for Learning Management Systems." In Open Source Solutions for Knowledge Management and Technological Ecosystems. IGI Global, 2017. http://dx.doi.org/10.4018/978-1-5225-0905-9.ch002.
Full textAbstract:
E-learning has experienced an extraordinary growth over the last years. We have reached a point in time when most learning institutions have adopted an LMS as an integral element of their teaching and learning infrastructure. In parallel, the number of educational tools available for learning is increasing and keeps evolving. This variety means that it is not always easy or possible to add these educational tools into LMSs to enhance the learning process. It would, however, be in everyone´s interest for these tools to interact with the LMSs. To solve the problem of interoperability between LMS and learning tools, several interoperability standards define ways so that LMSs can interface with external learning tools in order to make them accessible from within the learning platform in an intuitive and concise way. This chapter is focused on the service-oriented approach to interoperability and specifically on the IMS LTI standard and the TSUGI hosting environment that aims to simplify the integration of external learning tools.
6
Christ, Emanuel R., Christoph Stettler, Andrea Egger, et al. "The Effect of Aerobic Exercise on Intramyocellular (IMCL) and Intrahepatocellular Lipids (IHCL) in Hypopituitary Patients with Growth Hormone Deficiency (GHD), Sedentary Control Subjects (CS) and Endurance-Trained Athletes (EA)." In CLINICAL/TRANSLATIONAL - Growth Hormone: Physiology, Deficiency (Adult), Delivery Systems, Use in Other Syndromes. The Endocrine Society, 2011. http://dx.doi.org/10.1210/endo-meetings.2011.part2.p36.p2-363.
Full text
7
Ishaya, Tanko. "Towards Management of Interoperable Learning Objects." In Encyclopedia of Multimedia Technology and Networking, Second Edition. IGI Global, 2009. http://dx.doi.org/10.4018/978-1-60566-014-1.ch190.
Full textAbstract:
Developments in the Internet and the World Wide Web (WWW) technologies have led to an evolving trend in Electronic learning (e-learning). E-learning is now one of the most fast growing trends in computing and higher education (Ishaya & Wood, 2005) and certainly becoming a dominant way of learning in workplace settings across other organizations (Mungania, 2003). From its initial roots as an information-sharing tool, the Web has seen an exponential growth into a myriad of applications, ranging from very serious e-business to pure leisure environments. Likewise, research into technology support for education has quickly recognized the potential and possibilities for using the Web as a learning tool (Ishaya, Jenkins, & Goussios, 2002). Thus, the Web technology is now an established medium for promoting student learning, and today there are a great many online learning materials, tutorials, and courses supported by different learning tools with varying levels of complexity. It can be observed that there are many colleges and universities, each of which teaches certain concepts based on defined principles that remain constant from institution to institution. This results in thousands of similar descriptions of the same concept. This means that institutions spend a lot of resources producing multiple versions of the same learning objects that could be shared at much lower cost. The Internet is a ubiquitous supporting environment for sharing of learning materials. As a consequence, many institutions take advantage of the Internet to provide online courses (Ishaya et al., 2002; Jack, Bonk, & Jacobs, 2002; Manouselis, Panagiotou, Psichidou, & Sampson, 2002). Many other agencies have started offering smaller and more portable learning materials defined as learning objects (Harris, 1999; POMETEUS, 2002). Common standards for metadata, learning objects, and services are mandatory for the success of Web-based learning, which is why the creation of such standards for learning objects and related standards has being one of focus for research and development within the past few years. This includes the creation of accredited standards from the IEEE Learning Technology Standards Committee (LTSC) for Learning Object Metadata (LOM), Sharable Content Object Reference Model (SCORM), Instructional Management System (IMS), and so on. All these metadata models define how learning materials can be described in an interoperable way. There have also been intensive developments in the area of e-learning technology and the wide variety of learning environments from many different vendors (e.g., Sakai, Moodle, and Blackboard). While most of these approaches provide a means for describing, sharing, and reusing resources, the concept of interoperability and heterogeneous access to content chunks is yet to be fully achieved. This results in thousands of similar descriptions of the same concept, even within the same learning management system (LMS), and because these concepts may have been defined using different standards, they are not interoperable. What is required therefore is a mechanism and infrastructure for supporting a interoperable system of individual components that can be assembled by mixing and matching content from multiple sources to satisfy individual learner’s requirements. See Wood and Ishaya (2005) for a personality-based approach for building learner profiles.
Conference papers on the topic "Growth of IMCs"
1
Chauhan, Preeti, Michael Osterman, and Michael Pecht. "Impact of Thermal Aging on the Growth of Cu-Sn Intermetallic Compounds in Pb-Free Solder Joints in 2512 Resistors." In ASME 2009 International Mechanical Engineering Congress and Exposition. ASMEDC, 2009. http://dx.doi.org/10.1115/imece2009-10169.
Full textAbstract:
Interfacial intermetallic compounds (IMCs) in solder joints are formed during soldering and continue to grow after assembly. Excessive interfacial IMC growth may impact the reliability of solder interconnections due to changes in material behavior. The impact of thermal aging on IMC growth can be determined by subjecting assemblies to elevated temperatures and determining the interfacial IMC growth. This paper discusses the interfacial IMCs formed in the solder-Cu interface for SAC305, SAC105, and Sn-0.7Cu-0.05Ni+Ge (SN100C) assemblies. Test assemblies were produced using tin-finished 2512 resistors soldered onto OSP-finished copper lands. The assemblies were subjected to aging conditions of 100°C for 24 h and 600 h; and 150°C for 24 h and the impact of high temperature aging on the thickness of IMCs formed at solder-Cu interface was studied. Samples stored at room temperature for 600 h were the reference specimen for the experiment. The IMC growth observed in the lead-free solders was compared with that in eutectic SnPb. Interfacial IMCs formed in room temperature conditioned specimens were scallop shaped and non-uniform. The IMC structure evolved with aging temperature and duration resulting in smoother and more uniform IMCs in 100°C/600 h aged samples. A comparison of IMC thickness in the solders at given aging conditions revealed that SAC305 exhibited highest IMC thickness, followed by SAC105 and SN100C. SnPb showed the least IMC thickness at all aging conditions except at 150°C for 24 h. At this condition, SnPb showed IMC thickness comparable to SAC305 solder and was higher than other solders.
2
Choudhury, Soud Farhan, and Leila Ladani. "Anisotropic Behavior of Single Grain Cu6Sn5 Intermetallic." In ASME 2014 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/imece2014-40196.
Full textAbstract:
Intermetallic (IMC) layers (Cu6Sn5 and Cu3Sn) are an essential component of a solder joint for good metallurgical bonding. However, the mechanical and physical properties of IMC layers differ significantly from the solder and substrate, and excessive IMC layers can lower the reliability of solder joints due to their brittle nature. Moreover, continuous miniaturization of packages and joints has increased the volume fraction of IMCs to a point where smaller joints could be completely composed of IMCs. Further miniaturization of joints may result in statistical grain size effects. One of the most common types of IMCs in microelectronic joints is Cu6Sn5, which is formed in a variety of bonding materials with different compositions of Sn, Cu, and Ag. Due to its large percentage of volume in solder joint; to predict the reliability of micro solder joints, it is necessary to characterize single crystal Cu6Sn5 IMC completely. This study reports the information on grain growth orientation and elastic-plastic properties such as young’s modulus, hardness, yield strength and strain hardening exponent of single grain of Cu6Sn5 in Sn-3.5Ag/Cu solder alloy system. IMCs materials were grown using reflow process using an experiment in which the time and temperature of reflow process was varied. Electron backscatter diffraction (EBSD) analysis was conducted after the reflow to measure the grain size and determine the preferred grain orientation. It was found that the growth orientation is in the orientation of the c-axis. Nanoindentation was carried out in 4 individual grains with different crystallographic orientation along normal to the growth axis to determine the elastic properties of Cu6Sn5 single crystal. Plastic properties were predicted using the nanoindentation results and Dao reverse analysis model. The results indicate that the hardness for Cu6Sn5 grains with different orientation along normal to growth axis is statistically indistinguishable. Lower elastic modulus was observed for a grain with [010] direction parallel to the loading direction. Yield strength of a grain with (001) plane parallel to the loading direction was slightly lower than other grain orientations. Overall, the experimental results obtained were found to be within the range shown in the literature.
3
Pang, John H. L., and Luhua Xu. "Board-Level Drop Reliability Performance Before and After Thermal Cycling Aging." In ASME 2007 InterPACK Conference collocated with the ASME/JSME 2007 Thermal Engineering Heat Transfer Summer Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/ipack2007-33738.
Full textAbstract:
The combined sequential reliability test of thermal cycling aging followed by board level drop test for lead-free SnAgCu soldered assemblies were investigated. Interfacial IMCs, Kirkendall voids formation and interconnect failure mode are studied subject to TC aging. Kirkendall voids were observed with Ar+ sputtering etching. The failure sites and mechanism were examined and correlated with IMC and void formation. Significant decrease of drop life was observed for both SAC/ENIG and SAC/Cu-OSP assemblies after thermal cycling aging. Growth of Kirkendall voids and IMC significantly weakened the solder joint interface during TC aging. Drop impact crack path changed from the IMC to the IMC/Cu interface.
4
Galstyan, V., E. Comini, C. Baratto, et al. "P2.7.8 Growth and Gas Sensing Properties of Rough ZnO Nanowires." In 14th International Meeting on Chemical Sensors - IMCS 2012. AMA Service GmbH, Von-Münchhausen-Str. 49, 31515 Wunstorf, Germany, 2012. http://dx.doi.org/10.5162/imcs2012/p2.7.8.
Full text
5
Fanjul Bolado, P., M. M. P. S. Neves, M. B. González García, and D. Hernández Santos. "P1BS.6 - Cell Culture Growth Monitoring using Disposable Electrochemical Enzymatic Sensors." In 17th International Meeting on Chemical Sensors - IMCS 2018. AMA Service GmbH, Von-Münchhausen-Str. 49, 31515 Wunstorf, Germany, 2018. http://dx.doi.org/10.5162/imcs2018/p1bs.6.
Full text
6
Kaur, Manmeet, Kailasa Ganapathi, Niranjan S. Ramgir, Niyanta Datta, D. K. Aswal, and S. K. Gupta. "P2.4.11 Growth and H2S Gas Sensing Properties of CuO Functionalized ZnO Nanotetrapod." In 14th International Meeting on Chemical Sensors - IMCS 2012. AMA Service GmbH, Von-Münchhausen-Str. 49, 31515 Wunstorf, Germany, 2012. http://dx.doi.org/10.5162/imcs2012/p2.4.11.
Full text
7
Pawar, Rajendra C., Jin-Woong Lee, Vikas B. Patil, and Caroline S. Lee. "4.3.1 Growth of Cactilike ZnO nanostructure from aqueous medium for gas sensor application." In 14th International Meeting on Chemical Sensors - IMCS 2012. AMA Service GmbH, Von-Münchhausen-Str. 49, 31515 Wunstorf, Germany, 2012. http://dx.doi.org/10.5162/imcs2012/4.3.1.
Full text
8
Liu, J., P. Kumar, I. Dutta, et al. "Effect of Interfacial Layers on the Performance of Cu-In Liquid Phase Sintered Composites as Thermal Interface and Interconnect Materials." In ASME 2011 Pacific Rim Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Systems. ASMEDC, 2011. http://dx.doi.org/10.1115/ipack2011-52221.
Full textAbstract:
In this study, a novel architecture composed of uniformly distributed high melting phase (HMP, e.g. Cu) in a low melting phase (LMP, e.g. In) matrix, which can be produced via liquid phase sintering (LPS), is proposed to produce next generation thermal interface materials (TIMs) and interconnect (IC) materials. The LMP determines the shear compliance of these composites whereas the HMP determines its thermal and electrical conductivities. The volume fraction of In was optimized to produce a Cu-In solder with suitable mechanical, electrical and thermal properties for TIM and IC applications. Since, Cu and In react to form several Cu-In intermetallic compounds (IMCs), which may deteriorate the long-term performance of these solders, interfacial-layers of Au and Al2O3 were applied on Cu to further improve the performance of the Cu-In solders. The effect of interfacial-layers on the reaction between Cu and In, during sintering at 160°C and during aging at 125°C, was studied and its impact on the mechanical, thermal and electrical properties was evaluated. Au interfacial layer (50∼200nm) quickly reacted with In to form AuIn2 IMC, which acted as a tenacious diffusion-barrier and slowed down the reactions between Cu and In. 8-monolayer thick Al2O3 did not react with either Cu or In and inhibited reactions between Cu and In. During short-time sintering, the effect of interfacial layer on the thicknesses of IMCs was insignificant to affect the yield strength of the as-sintered composites. However, IMC layer thickened rapidly in the Cu-In composites without an interfacial-layer, which led to a drastic decrease in the volume fraction of unreacted In leading to an increase in the yield strength of the solder. On the other hand, the interfacial-layers effectively suppressed the growth of IMCs during aging and hence the yield strength of such composites increased at slower rates. Since, the IMCs formed at the interface radically affect the contact resistance, significant differences in the thermal and electrical conductivities were recorded for the solders with different interfacial-layers.
9
Copeland, Lucas, and Mukul Saran. "Copper to Aluminum Bonding: IMC Characterization through New Mechanical Sectioning Methods." In ISTFA 2010. ASM International, 2010. http://dx.doi.org/10.31399/asm.cp.istfa2010p0181.
Full textAbstract:
Abstract This paper presents a mechanical cross-sectioning approach that produces an image clarity not yet demonstrated in published literature. It demonstrates how a critical sequence of polishing, basic slurry optimization and staining, in conjunction with correct imaging parameters can be used to highlight the growth morphology of the intermetallic compound (IMCs). Utilizing this approach, the paper describes the results of a SEM imaging study of the intermetallic formation and growth at the Cu-Al bond interface during thermal ageing for up to 4000hrs at 150 deg C. The paper uses direct SEM imaging to catalog observations which are used to create an initial model for IMC and void growth at the wire bonded interface. It examines the effect of aluminum splash and concludes that growth of intermetallics at the Cu-Al interface is rapid into the bond-pad aluminum than into the Cu-ball, but the growth thickness uniformity is much higher into the Cu-ball.
10
Zytkiewicz, Z. R., M. Sobanska, K. Klosek, et al. "P2.4.18 MBE growth of GaN nanowires on Si(111) substrates for gas sensor applications." In 14th International Meeting on Chemical Sensors - IMCS 2012. AMA Service GmbH, Von-Münchhausen-Str. 49, 31515 Wunstorf, Germany, 2012. http://dx.doi.org/10.5162/imcs2012/p2.4.18.
Full text