352 results on '"BGA"'
Search Results
2. Multiple blood gas variables predict AKI survival in an independent manner
- Author
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Rebecca Lehmann, Oliver Ritter, Johanna Tennigkeit, Susann Patschan, and Daniel Patschan
- Subjects
AKI ,BGA ,pH ,pCO2 ,Actual bicarbonate ,Survival ,Diseases of the genitourinary system. Urology ,RC870-923 - Abstract
Abstract Background and aim Acute kidney injury (AKI) is becoming increasingly prevalent among hospitalized patients and carries a poor prognosis. While new biomarkers show promise in identifying early stages of AKI, accurately predicting severe outcomes such as the need for kidney replacement therapy (KRT) or death remains a challenge. However, blood gas analyses (BGA) can be used to diagnose life-threatening complications associated with AKI. The objective of this study was to assess the role of BGA as a biomarker panel in both emerging and established cases of AKI. Methods Retrospective observational study examining subjects with newly developed acute kidney injury (AKI). The study will document venous and arterial pH, pCO2, and actual bicarbonate levels upon hospital admission and at the onset of AKI. The primary endpoints include in-hospital mortality, the need for kidney replacement therapy (KRT), and the recovery of kidney function (ROKF). Results A total of 202 individuals were included in the study. Three variables were found to be independent predictors of in-hospital survival: admission arterial pH, arterial pH at acute kidney injury (AKI) onset, and arterial pCO2 at AKI onset. Additionally, venous pCO2 at AKI onset was identified as an independent predictor for the need of kidney replacement therapy (KRT). Conclusions Our study suggests that blood gas analysis may have a potential role in predicting severe outcome variables in acute kidney injury (AKI). The associated costs are minimal.
- Published
- 2024
- Full Text
- View/download PDF
3. Blue-green algae: Diversity and community structure in rice fields of Saran, Bihar
- Author
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Kumari, Sachi and Jha, Amrendra Kumar
- Published
- 2023
- Full Text
- View/download PDF
4. Multiple blood gas variables predict AKI survival in an independent manner
- Author
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Lehmann, Rebecca, Ritter, Oliver, Tennigkeit, Johanna, Patschan, Susann, and Patschan, Daniel
- Published
- 2024
- Full Text
- View/download PDF
5. Freshwater Blue–Green Algae: A Potential Candidate for Sustainable Agriculture and Environment for the Welfare of Future Planet Earth
- Author
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Rai, Arun Kumar, Gogoi, Binu, Gurung, Rabina, Soni, Ravindra, editor, Suyal, Deep Chandra, editor, Morales-Oyervides, Lourdes, editor, and Sungh Chauhan, Jaspal, editor
- Published
- 2023
- Full Text
- View/download PDF
6. Characterization of MEMS Inertial Measurement Unit Package with Digital Image Correlation
- Author
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Del Sarto, M., Napolitano, T., Manca, N., Angrisani, Leopoldo, Series Editor, Arteaga, Marco, Series Editor, Panigrahi, Bijaya Ketan, Series Editor, Chakraborty, Samarjit, Series Editor, Chen, Jiming, Series Editor, Chen, Shanben, Series Editor, Chen, Tan Kay, Series Editor, Dillmann, Rüdiger, Series Editor, Duan, Haibin, Series Editor, Ferrari, Gianluigi, Series Editor, Ferre, Manuel, Series Editor, Hirche, Sandra, Series Editor, Jabbari, Faryar, Series Editor, Jia, Limin, Series Editor, Kacprzyk, Janusz, Series Editor, Khamis, Alaa, Series Editor, Kroeger, Torsten, Series Editor, Li, Yong, Series Editor, Liang, Qilian, Series Editor, Martín, Ferran, Series Editor, Ming, Tan Cher, Series Editor, Minker, Wolfgang, Series Editor, Misra, Pradeep, Series Editor, Möller, Sebastian, Series Editor, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Oneto, Luca, Series Editor, Pascucci, Federica, Series Editor, Qin, Yong, Series Editor, Seng, Gan Woon, Series Editor, Speidel, Joachim, Series Editor, Veiga, Germano, Series Editor, Wu, Haitao, Series Editor, Zamboni, Walter, Series Editor, Zhang, Junjie James, Series Editor, Di Francia, Girolamo, editor, and Di Natale, Corrado, editor
- Published
- 2023
- Full Text
- View/download PDF
7. Numerical Investigation of the Evolving Inelastic Deformation Path of a Solder Ball Joint under Various Loading Conditions.
- Author
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Lim, Jae-Hyuk, Lee, Da-Hun, and Lee, Eun-Ho
- Subjects
SOLDER joints ,STRAINS & stresses (Mechanics) ,PRINTED circuit design ,DEFORMATIONS (Mechanics) ,DUCTILE fractures ,ELASTOPLASTICITY ,MECHANICAL failures - Abstract
Solder joints of ball grid arrays (BGA) have been widely used to connect electronic components to printed circuit boards (PCBs) and are often subjected to mechanical stress. Several studies have been conducted on the mechanical reliability of solder joints. While these studies have been useful in the industry, detailed studies on how the inelastic deformation path of the solder ball joints evolves under specific loading conditions have not been sufficiently reported. This study aims to understand how the inelastic deformation path evolves when a solder joint is subjected to a constant external force by utilizing the theory of mechanics. It has also been found that the mechanical failure is strongly influenced by the evolution history of the deformation modes in materials. For this study, an elastoplastic constitutive model and a ductile fracture criterion were implemented into the vectorized user-defined material (VUMAT) subroutine of the ABAQUS program for finite element (FE) analysis. With the model, the evolution of the inelastic deformation path of a single solder ball under different loading conditions was numerically analyzed. Three loadings (shear, compression, and bending) were chosen as the basic loading conditions. In addition, combinations of the basic loadings resulted in three dual loadings and one complex loading. The simulation results showed that the shear and bending caused the fracture for both single and dual loadings, but when combined with compression, the fracture was suppressed. The results indicate that fracture is not solely determined by the magnitude of equivalent plastic strain but also by the evolution of inelastic deformation mode. This research offers an improved understanding of the significance of the inelastic deformation path and fracture. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
8. SoC Packaging
- Author
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Chakravarthi, Veena S. and Chakravarthi, Veena S.
- Published
- 2022
- Full Text
- View/download PDF
9. BGA Solder Ball Attaching Process Using Surface Tension of Liquid Solder
- Author
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Xie, Xin, Jin, Dayuan, Wan, Yun, Angrisani, Leopoldo, Series Editor, Arteaga, Marco, Series Editor, Panigrahi, Bijaya Ketan, Series Editor, Chakraborty, Samarjit, Series Editor, Chen, Jiming, Series Editor, Chen, Shanben, Series Editor, Chen, Tan Kay, Series Editor, Dillmann, Rüdiger, Series Editor, Duan, Haibin, Series Editor, Ferrari, Gianluigi, Series Editor, Ferre, Manuel, Series Editor, Hirche, Sandra, Series Editor, Jabbari, Faryar, Series Editor, Jia, Limin, Series Editor, Kacprzyk, Janusz, Series Editor, Khamis, Alaa, Series Editor, Kroeger, Torsten, Series Editor, Li, Yong, Series Editor, Liang, Qilian, Series Editor, Martín, Ferran, Series Editor, Ming, Tan Cher, Series Editor, Minker, Wolfgang, Series Editor, Misra, Pradeep, Series Editor, Möller, Sebastian, Series Editor, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Oneto, Luca, Series Editor, Pascucci, Federica, Series Editor, Qin, Yong, Series Editor, Seng, Gan Woon, Series Editor, Speidel, Joachim, Series Editor, Veiga, Germano, Series Editor, Wu, Haitao, Series Editor, Zamboni, Walter, Series Editor, Zhang, Junjie James, Series Editor, Duan, Baoyan, editor, Umeda, Kazunori, editor, and Kim, Chang-wan, editor
- Published
- 2022
- Full Text
- View/download PDF
10. Advanced Packages and 3D-SoC Designs
- Author
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Chakravarthi, Veena S., Koteshwar, Shivananda R., Chakravarthi, Veena S., and Koteshwar, Shivananda R.
- Published
- 2022
- Full Text
- View/download PDF
11. SiP Design Flow Based on Advanced Package (HDAP)
- Author
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Li, Suny and Li, Suny, editor
- Published
- 2022
- Full Text
- View/download PDF
12. Practical Tips in Electronics
- Author
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Siu, Christopher and Siu, Christopher
- Published
- 2022
- Full Text
- View/download PDF
13. Automated X-ray Defect Inspection on Occluded BGA Balls Using Hybrid Algorithm.
- Author
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Ki-Yeol Eom and Byungseok Min
- Subjects
X-rays ,X-ray imaging ,CENTER of mass ,THREE-dimensional imaging ,COMPUTED tomography - Abstract
Automated X-ray defect inspection of occluded objects has been an essential topic in semiconductors, autonomous vehicles, and artificial intelligence devices. However, there are few solutions to segment occluded objects in the X-ray inspection efficiently. In particular, in the Ball Grid Array inspection of X-ray images, it is difficult to accurately segment the regions of occluded solder balls and detect defects inside solder balls. In this paper, we present a novel automatic inspection algorithm that segments solder balls, and detects defects fast and efficiently when solder balls are occluded. The proposed algorithm consists of two stages. In the first stage, the defective candidates or defects are determined through the following four steps: (i) image preprocessing such as noise removal, contrast enhancement, binarization, connected component, and morphology, (ii) limiting the inspection area to the ball regions and determining if the ball regions are occluded, (iii) segmenting each ball region into one or more regions with similar gray values, and (iv) determining whether there are defects or defective candidates in the regions using a weighted sum of local threshold on local variance. If there are defective candidates, the determination of defects is finally made in the following stage. In the second stage, defects are detected using the automated inspection technique based on oblique computed tomography. The 3D precision inspection process is divided into four steps: (i) obtaining 360 projection images (one image per degree) rotating the object from 0 to 360 degrees, (ii) reconstructing a 3D image from the 360 projected images, (iii) finding the center slice of gravity for solder balls from the axial slice images in the z-direction, and getting the inspection intervals between the upper bound and the lower bound from the center slice, and (iv) finally determining whether there are defects in the averaged image of solder balls. The proposed hybrid algorithm is robust for segmenting the defects inside occluded solder balls, and improves the performance of solder ball segmentation and defect detection algorithm. Experimental results show an accuracy of more than 97%. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
14. A study on the effects of electrical and thermal stresses on void formation and migration lifetime of Sn3.0Ag0.5Cu solder joints
- Author
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Li, Yanruoyue, Fu, Guicui, Wan, Bo, Wu, Zhaoxi, Yan, Xiaojun, and Zhang, Weifang
- Published
- 2022
- Full Text
- View/download PDF
15. Numerical Investigation of the Evolving Inelastic Deformation Path of a Solder Ball Joint under Various Loading Conditions
- Author
-
Jae-Hyuk Lim, Da-Hun Lee, and Eun-Ho Lee
- Subjects
inelastic deformation path ,solder joint ,BGA ,ductile fracture criterion ,finite element method ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Solder joints of ball grid arrays (BGA) have been widely used to connect electronic components to printed circuit boards (PCBs) and are often subjected to mechanical stress. Several studies have been conducted on the mechanical reliability of solder joints. While these studies have been useful in the industry, detailed studies on how the inelastic deformation path of the solder ball joints evolves under specific loading conditions have not been sufficiently reported. This study aims to understand how the inelastic deformation path evolves when a solder joint is subjected to a constant external force by utilizing the theory of mechanics. It has also been found that the mechanical failure is strongly influenced by the evolution history of the deformation modes in materials. For this study, an elastoplastic constitutive model and a ductile fracture criterion were implemented into the vectorized user-defined material (VUMAT) subroutine of the ABAQUS program for finite element (FE) analysis. With the model, the evolution of the inelastic deformation path of a single solder ball under different loading conditions was numerically analyzed. Three loadings (shear, compression, and bending) were chosen as the basic loading conditions. In addition, combinations of the basic loadings resulted in three dual loadings and one complex loading. The simulation results showed that the shear and bending caused the fracture for both single and dual loadings, but when combined with compression, the fracture was suppressed. The results indicate that fracture is not solely determined by the magnitude of equivalent plastic strain but also by the evolution of inelastic deformation mode. This research offers an improved understanding of the significance of the inelastic deformation path and fracture.
- Published
- 2023
- Full Text
- View/download PDF
16. Natural and Constructed Cyanobacteria-Based Consortia for Enhancing Crop Growth and Soil Fertility
- Author
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Prasanna, Radha, Renuka, Nirmal, Nain, Lata, Ramakrishnan, B., Arora, Naveen Kumar, Series Editor, Seneviratne, Gamini, editor, and Zavahir, Junaida Shezmin, editor
- Published
- 2021
- Full Text
- View/download PDF
17. Optimization of Deep Reservoir Computing with Binary Genetic Algorithm for Multi-Time Horizon Forecasting of Power Consumption.
- Author
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Bendali, Wadie, Saber, Ikram, Boussetta, Mohammed, Bourachdi, Bensalem, and Mourad, Youssef
- Subjects
DEEP learning ,ENERGY consumption forecasting ,GENETIC algorithms ,PROCESS capability ,FORECASTING ,TIME perspective - Abstract
The roll of consumption energy forecasting is very important to make planning of timehorizon strategy, and to mitigate a great energy management. As a result, improving the sustainability of energy, and creating a clean environment. Aiming to develop the forecasting of consumption energy in different time horizons, this work gives the results of a new hybrid method, which combine deep echo state network (DeepESN), with Binary genetic algorithm (BGA). DeepESN is an extension of Echo state network (ESN), which integrates the strong nonlinear time series processing capability (of ESN) with the advanced learning characteristic of the deep learning models. BGA is another version of genetic algorithm optimization methods that can be applied to find the best values of architecture hyperparameters of deep learning models, based on binary decoding of his chromosoms. In this work, we compared the accuracy and performance of proposed model DeepESN-BGA with other deep learning methods. It is found that DeepESN-BGA have a fast processing compared with other models. In addition, it gives best results based on error metrics, compared with DeepESN without BGA, and other deep learning models, in different time horizon forecasting. Proposed model has been compared also with DeepESN-DE, DeepESN-GA, and DeepESN-PSO aiming to evaluate the performance of BGA in term of deep learning optimization. DeepESN-BGA gives statistically good result compared with other hybrid models. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
18. Systematic Verification of BGA Solder Joint Reliability in Multiple Ways
- Author
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Lu, Wei, Jin, Dayuan, Wan, Yun, Angrisani, Leopoldo, Series Editor, Arteaga, Marco, Series Editor, Panigrahi, Bijaya Ketan, Series Editor, Chakraborty, Samarjit, Series Editor, Chen, Jiming, Series Editor, Chen, Shanben, Series Editor, Chen, Tan Kay, Series Editor, Dillmann, Rüdiger, Series Editor, Duan, Haibin, Series Editor, Ferrari, Gianluigi, Series Editor, Ferre, Manuel, Series Editor, Hirche, Sandra, Series Editor, Jabbari, Faryar, Series Editor, Jia, Limin, Series Editor, Kacprzyk, Janusz, Series Editor, Khamis, Alaa, Series Editor, Kroeger, Torsten, Series Editor, Liang, Qilian, Series Editor, Martin, Ferran, Series Editor, Ming, Tan Cher, Series Editor, Minker, Wolfgang, Series Editor, Misra, Pradeep, Series Editor, Möller, Sebastian, Series Editor, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Pascucci, Federica, Series Editor, Qin, Yong, Series Editor, Seng, Gan Woon, Series Editor, Speidel, Joachim, Series Editor, Veiga, Germano, Series Editor, Wu, Haitao, Series Editor, Zhang, Junjie James, Series Editor, Duan, Baoyan, editor, Umeda, Kazunori, editor, and Hwang, Woonbong, editor
- Published
- 2020
- Full Text
- View/download PDF
19. SOC Packaging
- Author
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Chakravarthi, Veena S. and Chakravarthi, Veena S.
- Published
- 2020
- Full Text
- View/download PDF
20. Heat transfer and deformation analysis of flexible printed circuit board under thermal and flow effects
- Author
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Lim, Chong Hooi, Abdullah, M.Z., Abdul Azid, I., Khor, C.Y., Abdul Aziz, M.S., and Ishaik, M.H.H.
- Published
- 2021
- Full Text
- View/download PDF
21. Class I Creep Deformation of Sn-Ag-Cu Containing Solid Solution Elements and Its Effect on Thermal Fatigue Life of Solder Joints.
- Author
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Masaki Moriuchi, Yoshiharu Kariya, Mao Kondo, and Yoshihiko Kanda
- Subjects
THERMAL fatigue ,SOLDER joints ,SOLID solutions ,DEFORMATIONS (Mechanics) ,SOLUTION strengthening ,TIN alloys - Abstract
The creep deformation mechanism of SnAgCu alloy doped with Bi and Sb (SACBiSb) alloys is theoretically and experimentally analyzed in order to clarify the effect of solid solution additives in SnAgCu alloys. The theoretical prediction results and test results are found to mostly agree with each other. The breakaway stress which is the stress at the transition from Class II to Class I in particular is finely reproduced in the theoretical prediction, with a stress of 25 MPa found both by the prediction and test results. In the stress range where the stress is higher than the breakaway stress, the creep strength of SACBiSb is higher than that of SnAgCu, while it was predicted that the creep strength of SnAgCu would be superior to that of SACBiSb in the range of stress lower than the breakaway stress. The thermal fatigue life of SACBiSb was predicted to be longer than that of SnAgCu in the temperature profile mainly used above the breakaway stress. However, in the temperature profile mainly used in the low-stress range, a reversal of the creep strength between SACBiSb and SnAgCu was predicted to occur and the loss of the superiority of SACBiSb in the thermal fatigue life was also predicted. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
22. STUDIES ON THE EFFECT OF VARIOUS LEVELS OF NITROGENOUS FERTILIZER ALONG WITH SOME NITROGEN FIXING BLUE GREEN ALGAE ON SOME YIELD ATTRIBUTES OF RICE VARIETIES CV. PUSA 1509 AND PUSA SHARBATI.
- Author
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Gautam, Ambika Singh and Khare, Alok Kumar
- Subjects
NITROGEN fertilizers ,ANIMAL feeding behavior ,PLANT growth ,CYANOBACTERIA ,RICE yields - Abstract
Nitrogen is indispensible ingredient of animal food and comes initially from plant. In fact, plant converts the nitrogen of soil in two forms suitable for nutrition of animals. After water, nitrogen is the second limiting factor for plant growth in many fields and deficiency of this element is met by fertilizers. The excessive use of chemical fertilizer has generated several environmental issues. These problems can be tackled by use of Bio-fertilizers. Bio-fertilizers are different from Chemical fertilizers. Bio-fertilizer on the application remains in soils, multiply and keep benefiting the growing crops. Blue green algae (BGA) or Cyanobacteria, the free-living photosynthetic N-fixing organism, are distributed worldwide and contribute to the soil fertility in many agricultural ecosystem. Cyanobacteria function as a Bio-fertilizer due to the property of nitrogen fixation (conversion of molecular nitrogen into nitrogen compound). The mass production of Cyanobacteria is much cheaper and easy than that of conventional chemical fertilizer and their inorganic requirement is very simple. To test the efficacy of nitrogenous fertilizer along with BGA on the yield attributes of rice, a field experiment was conducted with rice variety Pusa 1509 and Pusa sharbati. Two fields of 2.0 m into 3.0 m were prepared one without BGA as control and other with BGA. For this field experiment recommended dose of BGA is 10 kg/ha after the transplantation of rice seedlings. Inoculates contains the mixture of Gloeocapsa, Plectonema, Oscillatoria, Anabaena, Nostoc, Cylindrospermum, Scytonema, Calothrix, Anabaenopsis, Aulosira, Eisherella etc. As compared with control tillers were seen after 80 days, food grains were thick, elongated and healthy and 10-30 percent grain yield found to be increased over control. The observation clearly indicates that the BGA can be the good option to increase the growth and crop production in Rice. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
23. Design and Realization of a W-Band Antenna in Package (AiP) Array Based on Silicon and Quartz.
- Author
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Cao, Zhixiang, Yang, Jiapeng, and Meng, Hongfu
- Subjects
- *
POWER dividers , *WAFER level packaging , *ANTENNA arrays , *ANTENNAS (Electronics) , *SILICON - Abstract
This paper presents a novel W-band AiP array based on the wafer-level packaging technology with through silicon via (TSV). The proposed antenna array is composed of 2 × 4 radiation elements, a grounded coplanar waveguide (GCPW) to strip line (SL) vertical transition, and a GCPW power divider network. The substrate of the radiation element is quartz, which is welded to the silicon by ball grid array (BGA). The GCPW-to-SL vertical transition based on TSV and ball bumping realizes low-loss interconnection between different silicon layers. The GCPW power divider network feeds the 2 × 4 radiation elements with equal amplitudes and equal phases. The measured results show that the insertion loss of the GCPW-to-SL vertical transition is less than 2 dB in the working frequency range of 90–96 GHz and the gain of the proposed AiP array is about 9.5 dBi at 93 GHz, which verify the feasibility of the AiP solution at W-band. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
24. 高集成小型化中频滤波组件设计与实现.
- Author
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白锐, 徐达, 杨亮, 孙从科, and 王绍东
- Subjects
- *
FILTER banks , *SOLDER & soldering , *RADAR - Abstract
To meet the demand of large number and high integration of filters in the IF filter modules of radar receivers, a miniaturization LC filter based on the 3D integration technology is proposed in this study. The application and integrating process of 3D LC filter in modules are studied and analyzed. The 3D LC filter adopts two substrates, and uses 3D integration process and BGA technology to realize the three-dimensional integrated assembly of the two substrates. High-density layout can be realized by placing capacitive elements on the bottom substrate. Inductive elements are placed on the top substrate and separated from the capacitive elements, and signal communication is achieved through solder balls. The use of a three-dimensional integration scheme can reduce the size of the LC filter circuit by nearly 50%, and the filter index is consistent with the performance of the planar filter circuit. Compared with the traditional IF filter component design method, this solution is more conducive to achieve high integration and miniaturization. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
25. Effect of Plant Growth-Promoting Rhizobacteria and Cyanobacteria on Physico-chemical and cooking characteristics of Giza 179 rice grains.
- Author
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Elekhtyar, Nehal M., Awad-Allah, Mamdouh M. A., and Zidan, Abdo A.
- Subjects
- *
RICE , *AMYLOSE , *CYANOBACTERIA , *FAT , *GRAIN yields , *GRAIN , *BIOFERTILIZERS , *GREEN algae - Abstract
Rice's market worth is mostly determined by its physico-chemical quality, as well as its cooking and eating efficiency. The milling characteristics of Egyptian rice Giza 179 cv. are problematic. Through the finest agronomic techniques of rice, we hope to solve this problem. A field experiment has been performed at the Rice Research and Training Center (RRTC), Sakha, Kafrelsheikh, Egypt in the 2019 and 2020 seasons. Plant growth-promoting rhizobacteria (PGPR) and cyanobacteria (blue green algae, BGA) have been used as biofertilizers, evaluating their impact on yield and grain quality. Combining inorganic nitrogen in the form of urea with biofertilizers improved grain yield and physicochemical and cooking characteristics such as milling properties (hulling%, milling%, and head rice%), cooking and eating quality characteristics (gelatinization temperature, gel consistency test, amylose content%, and kernel elongation%), physical characteristics (grain length, width, and shape), chemical compositions (nitrogen uptake, protein content, ash content, fat%, and carbohydrate%. PGPR and BGA inoculation in combination with 110 Kg ha-1 of N resulted in the greatest values of these characteristics, except carbohydrate% and grain shape, with no significant changes in inorganic nitrogen at the recommended rate of 165 Kg ha-1 of N. Fertilization that contains biofertilizers enriches the Egyptian Giza 179 rice grain's physical, chemical, and cooking qualities. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
26. Prediction of Solder Joint Reliability with Applied Acrylic Conformal Coating.
- Author
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Vieira, Duarte Nuno, Lima, Ana, Santos, Duarte, Rodrigues, Nélson, Carvalho, Violeta, Puga, Hélder, Teixeira, Senhorinha F. C. F, and Teixeira, José Carlos
- Subjects
SOLDER joints ,CONFORMAL coatings ,ACRYLIC coatings ,FINITE element method ,THERMOMECHANICAL properties of metals ,FAILURE analysis ,EXTRAPOLATION - Abstract
The exposure of miniaturized components to the environment leads to new failure analysis as a result of environmental conditions and constant innovation of the component materials and dimensions. Generally, these failures occur on the solder joints, which ensure the mechanical and electrical connection between the printed circuit board and the component. Conformal coating is a thin layer of a polymeric material that encapsulates the components and consequently their solder joints to protect against harsh environments. However, this application is not recommended in some components such as ball grid array and quad flat no-lead (QFN) packages, since it can reduce the reliability of the solder joints when exposed to temperature fluctuations. Therefore, by using a finite element analysis, a thermal cycle test was simulated with and without conformal coating. The simulation output was extrapolated to lifetime theoretical methods with the aim of predicting the number of cycles until the failure of the solder joints. Therefore, this study demonstrates that for both components without conformal coating, solder joint lifetime was a precise approximation. Coated solder joints reveal a drastic reduction in their reliability due to the influence of the conformal coating behavior and its thermomechanical properties. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
27. Effect of irrigation and nitrogen management on yield and economics of SRI-grown hybrid rice (Oryza sativa)
- Author
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MADANE ANANDA JAGANNATH, J K SINGH, and VIJAY PRATAP
- Subjects
BGA ,Irrigation scheduling ,Recommended dose of nitrogen ,System of rice intensification ,Sesbania ,Agriculture - Abstract
A field experiment was conducted during rainy season (2014-15) at Banaras Hindu University, Varanasi to standardize water saving and economical nitrogen management options for hybrid rice (Oryza sativa L.) under SRI.The experiment was laid-out in a three-times replicated split-plot design involving three irrigation scheduling, viz. irrigation at 2 days after disappearance of ponded water (DADPW), 5 DADPW and 8 DADPW assigned to main-plotsand five nitrogen management options, viz. 100% recommended dose of nitrogen (RDN, 150 kg N/ha), 100% RDN+ Sesbania aculeata, 75% RDN + Sesbania aculeata, 100% RDN + BGA (12 kg/ha) and 75% RDN + BGA (12 kg/ha) were allotted in sub-plots. Results reveal that scheduling of irrigation at 2 DADPW was recorded significantly higher dry matter accumulation (DMA), leaf area index (LAI), yield attributes and finally enhanced grain yield andnet returns by 16.2, 20.3% and 11.7 and 12.6% during 2014 and 2015, respectively over 8 DADPW but statistically at par with scheduling of irrigation at 5 DADPW. Among nitrogen management options, application of 100% RDN(150 kg N/ha) + BGA (12 kg/ha) recorded higher DMA, LAI, yield attributes and finally enhanced grain yield andnet returns by 14.4, 22.8% and 12.6 and 18.5%, respectively over application of 100% RDN alone. Hence, irrigation at 2 DADPW and combined application of 100% RDN + BGA (12 kg/ha) can be recommended for obtaining higher yield and profit from hybrid rice under SRI.
- Published
- 2021
- Full Text
- View/download PDF
28. Conventional Design Flow
- Author
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Yazdani, Farhang and Yazdani, Farhang
- Published
- 2018
- Full Text
- View/download PDF
29. Pathfinding and Co-design
- Author
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Yazdani, Farhang and Yazdani, Farhang
- Published
- 2018
- Full Text
- View/download PDF
30. Wirebond Physical Implementation
- Author
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Yazdani, Farhang and Yazdani, Farhang
- Published
- 2018
- Full Text
- View/download PDF
31. Growth of soyabean [Glycine Max L. (Merr)] under the influence of blue green algal (BGA) Biofertilizer
- Author
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Jadhav, S. R. and Talekar, S. M.
- Published
- 2020
32. Polarity effect of interfacial intermetallic compounds of BGA structure Cu/Sn–52In/Cu solder joints during electromigration.
- Author
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Huang, Jiaqiang, Zhu, Yunhui, Pan, Kunhong, Wang, Xudong, Huang, Zhaoling, Xiao, Dawei, and Jiang, Hongjie
- Subjects
- *
SOLDER joints , *INTERMETALLIC compounds , *ELECTRODIFFUSION , *INTERFACIAL reactions , *COPPER , *PHASE separation , *EUTECTICS - Abstract
Sn–52In eutectic solder has gradually attracted much attention due to the feature of low melting temperature in recent years. However, Sn–52In solder may occur melting due to the severe Joule heating and causes serious reliability problems. This study mainly investigated the interfacial reaction of ball grid array (BGA) structure Cu/Sn–52In/Cu solder joints during electromigration with current densities of 0.5 × 104 A/cm2, 1.0 × 104 A/cm2 and 1.5 × 104 A/cm2 at 70 °C, 115 °C and 140 °C, respectively. Results show that during the solid-solid (S–S) electromigration and liquid-solid (L-S) electromigration process, respectively, both the In and Cu atoms on the cathode side diffuse to the anode side to participate in the interfacial reaction to form the intermetallic compounds (IMCs), which not only causes the dissolution of the Cu substrate on the cathode side, but also leads to the polarity effect in the growth of interfacial IMCs, i.e., the interfacial IMCs on the anode side is much thicker than that on the cathode side, and the higher the current density and temperature, the more obvious the polarity effect. In addition, with the increase of current density and temperature, the type of interfacial IMCs on the anode side changes from the initial Cu 6 (Sn,In) 5 and Cu 2 In 3 Sn to Cu 6 (Sn,In) 5 during S–S electromigration, while that changes from the initial Cu 6 (Sn,In) 5 and Cu 2 In 3 Sn to the composition of Cu 6 (Sn,In) 5 and Cu 3 (In,Sn) for L-S electromigration. • Polarity effect exhibits in the growth of interfacial intermetallic compounds during solid-solid electromigration and liquid-solid electromigration. • The higher the current density and temperature, the more obvious the polarity effect. • The interfacial IMCs on the anode side is much thicker than that on the cathode side. • The phase separation of Sn-rich phase and In-rich phase does not appear during solid-solid electromigration. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
33. Bayesian calibration of ball grid array lifetime models for solder fatigue.
- Author
-
Tauscher, Markus, Lämmle, Sven, Roos, Dirk, and Wilde, Jürgen
- Subjects
- *
CALIBRATION , *SOLDER joints , *LEAD-free solder , *SOLDER & soldering , *FAILURE mode & effects analysis , *FINITE element method , *PARAMETER estimation , *BAYESIAN field theory - Abstract
One of the primary failure modes for solder joints is caused by temperature cycling of the component. The induced stress causes creeping which leads to crack initiation and propagation until failure. Finite element analysis can be used to simulate occurring creep-strain for different temperatures and geometries. Subsequently, creep-strain is used as damage parameter together with a lifetime model to estimate the reliability of the component. Economic factors constrain data available for calibration of the lifetime model, leading to uncertainties in parameter estimates and reliability. Therefore, we propose a model calibration method for solder fatigue with the Coffin–Manson lifetime model based on Bayesian inference. The approach is able to incorporate respective uncertainties from data variability and sparsity, and takes prior knowledge into account. We show how to obtain reliability estimates from the calibrated model considering uncertainties from parameter estimation. Furthermore, we apply the Bayesian calibration method to experimental data obtained from ball-grid arrays with lead-free SAC305 solder joints. In our ablation study we show that our approach is more robust and accurate upon the prevalent calibration method used, especially if only limited data is available. • We study physical lifetime of solder joints for BGA components. • Failures are monitored via daisy-chain and failure area estimation. • We present a Bayesian calibration strategy for the Coffin–Manson model. • Bayesian calibration considers prior knowledge and uncertainty from sparse data. • Our approach is more robust and accurate upon prevalent calibration methods used. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
34. Advanced Substrates: A Materials and Processing Perspective
- Author
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Appelt, Bernd K., Lu, Daniel, editor, and Wong, C.P., editor
- Published
- 2017
- Full Text
- View/download PDF
35. Adaptive surface distortions for torque ripple control in vertical-axis wind turbines.
- Author
-
Erfort, Gareth, von Backström, Theodor W, and Venter, Gerhard
- Subjects
TORQUE control ,VERTICAL axis wind turbines ,WIND turbines ,GENETIC algorithms ,DYNAMIC simulation ,URBAN ecology (Sociology) - Abstract
Vertical-axis wind turbines have been confined to small-scale generation in urban environments where their omnidirectional capability offers them an advantage over the more ubiquitous horizontal-axis wind turbine. With a drive towards renewable energy, more opportunities exist for the implementation of wind turbines in a multitude of environments. Based on its inherent operational drawbacks, the vertical-axis wind turbine has not undergone extensive investigation. Recently, there has been a resurgence of interest in the technology. This article addresses the torque ripple, a variation in torque produced by the turbine, present during operation. The variation in torque generated by a vertical-axis wind turbine increases the likelihood of failure due to fatigue. Current treatment is symptomatic and addresses the result of the torque fluctuation and not the cause. A novel blade design, capable of altering the lift and drag response through shape alteration, is presented as a solution. The blade design and operation is achieved through genetic algorithm optimization and computational fluid dynamic simulations. Comparisons with previous work show the novel blade presented here surpasses the reduction seen with pitching solutions. A 25% reduction in torque ripple was demonstrated for a 17% reduction in performance coefficient using the surface distortion approach. This surpasses the foil pitching approach which achieved a 15% torque ripple reduction for the same loss in performance coefficient. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
36. Fertilizers Effect Blue Green Algae and increasing their Toxins
- Author
-
Jessim, Ahmed Ibrahim
- Published
- 2018
- Full Text
- View/download PDF
37. Detection of BGA solder defects from X-ray images using deep neural network.
- Author
-
TÜRER AKDENİZ, Ceren, DOKUR, Zümray, and ÖLMEZ, Tamer
- Subjects
- *
X-ray imaging , *SOLDER joints , *SOLDER & soldering , *IMAGE processing , *DEEP learning - Abstract
In the literature it is observed that complex image processing operations are used in the classification of Ball Grid Array (BGA) X-ray images, however high classification results were not achieved. In recent years, it has been shown that deep learning methods are very successful especially in classification problems. In this study, a new deep neural network (DNN) model is proposed to classify the BGA X-ray images. The proposed DNN model contains feature extractor layers and a minimum distance classifier. Since the proposed network consists of less number of layers (4 convolution layers and 1 fully connected layer), determination of the hyper-parameters of the network and training of the network are accomplished in a short time. BGA X-ray images are categorized into 4 classes according to the conditions of the solder joints: normal, short-circuit, bonding defect and void defect. The dataset used in this study is comprised of 67, 76, 53 and 76 images for these classes, respectively. 80% of all data is allocated for the training set and the remaining 20% is allocated for the test set. Compared with the existing methods in the literature, a very high success rate of 97% is achieved for the classification of BGA X-ray images with the proposed method. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
38. Failure Analysis of SAC305 Ball Grid Array Solder Joint at Extremely Cryogenic Temperature.
- Author
-
Li, Yanruoyue, Fu, Guicui, Wan, Bo, Jiang, Maogong, Zhang, Weifang, and Yan, Xiaojun
- Subjects
SOLDER joints ,FAILURE analysis ,SOLDER & soldering ,X-ray detection ,LOW temperatures ,SCANNING electron microscopes - Abstract
Featured Application: It is an important trend that Pb-free materials in electronic devices/components are used in the aerospace field. Several reliability issues associated with this kind of material characteristic occurred and need in-depth studies. One of the issues is that Sn-rich material's characteristic changes under low-temperature. This change may cause components/device failure and has an influence on their reliability. This work of failure analysis provides an actual case of electronic components with failure when under harsh environments, such as extreme cryogenic temperature in space. It makes reliable use of Pb-free material under extremely cryogenic temperature conditions to be taken seriously, brings up an analysis process for this kind of failure, and suggestions for operating temperatures are put forward. To verify the reliability of a typical Pb-free circuit board applied for space exploration, five circuits were put into low temperature and shock test. However, after the test, memories on all five circuits were out of function. To investigate the cause of the failure, a series of methods for failure analysis was carried out, including X-ray detection, cross-section analysis, Scanning Electron Microscope (SEM) analysis, and contrast test. Through failure analysis, the failure was located in the Pb-free (Sn-3.0Ag-0.5Cu) solder joint, and we confirmed that the failure occurred because of the low temperature and change of fracture characteristic of Sn-3.0Ag-0.5Cu (SAC305). A verification test was conducted to verify the failure mechanism. Through analyzing data and fracture surface morphology, the cause of failure was ascertained. At low temperature, the fracture characteristic of SAC305 changed from ductileness to brittleness. The crack occurred at solder joints because of stress loaded by shock test. When the crack reached a specific length, the failure occurred. The temperature of the material's characteristic change was −70–−80 °C. It could be a reference for Pb-free circuit board use in a space environment. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
39. Controlling Environmental Crisis Messages in Uncontrollable Media Environments: The 2011 Case of Blue-Green Algae on Grand Lake O’ the Cherokees, OK
- Author
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Mason, Alicia M., Triplett, James R., Drake, Jeanette L., editor, Kontar, Yekaterina Y., editor, Eichelberger, John C., editor, Rupp, T. Scott, editor, and Taylor, Karen M., editor
- Published
- 2016
- Full Text
- View/download PDF
40. Response of Mixed Blue Green Algal Bio fertilizer on Yield of Rice (Oryza sativa) of Uttar Pradesh
- Author
-
Verma, D.C. and Srivastava, D.K.
- Published
- 2018
- Full Text
- View/download PDF
41. Investigating the Effect of Ag Content on Mechanical Properties of Sn-Ag-Cu Micro-BGA Joints.
- Author
-
Chen, Hao, Chou, Tzu-Ting, Fleshman, Collin, and Duh, Jenq-Gong
- Subjects
SOLDER joints ,SHEAR strength ,SHEARING force ,TIN alloys ,SILVER alloys ,SOLDER & soldering - Abstract
In order to evaluate the effect of Ag content on the mechanical property in micro-ball grid array (micro-BGA) solder joints, a shear test was carried out on Sn-3.0Ag-0.5Cu/Cu (wt.%) and Sn-4.0Ag-0.5Cu/Cu solder joints with a diameter of 90 μm. Corresponding microstructure before and after the shear test were investigated in this study. The shear test results demonstrated that the shear strength of Sn-4.0Ag-0.5Cu/Cu was greater than that of Sn-3.0Ag-0.5Cu/Cu. In Sn-4.0Ag-0.5Cu/Cu. The number of fine eutectic Ag
3 Sn particles in the solder matrix was higher, and the occurrence of plate-like Ag3 Sn formation was much more frequent than in Sn-3.0Ag-0.5Cu/Cu. Moreover, by applying a fallback mode shear test and observing the fracture surface, broken plate-like Ag3 Sn was found in the Sn-4.0Ag-0.5Cu/Cu joints with higher shear strength. These plate-like Ag3 Sn acted as obstacles against shear force and enhanced the shear strength of joints. Therefore, both fine Ag3 Sn precipitates and huge plate-like Ag3 Sn improved the shear performance of micro-BGA joints. In addition, the shear behavior of 250 μm solder joints was also investigated and discussed, which was not identical to micro-BGA joints. The strengthening effect of plate-like Ag3 Sn only occurred in micro-BGA joints, which had higher volume ratio of plate-like Ag3 Sn in solder joints. [ABSTRACT FROM AUTHOR]- Published
- 2019
- Full Text
- View/download PDF
42. Effect of Surface Finish on the Shear Properties of SnAgCu-Based Solder Alloys.
- Author
-
Su, Sinan, Hamasha, Sa'd, and Hamasha, Khozima
- Subjects
- *
SOLDER & soldering , *SURFACE finishing , *SOLDER joints , *SILVER alloys , *SHEAR strain , *STRESS-strain curves - Abstract
The reliability of an electronic assembly is typically limited by the failure of one of the solder interconnections. One of the key factors that define the quality of solder interconnections is the strength of the solder joint attachment to the printed circuit board (PCB). The ball shear testing is commonly used as a quantitative approach to evaluate the integrity of the solder. Several factors control the shear strength and failure mechanism of solder joints, including the surface finish, solder alloy composition, and speed of shearing (shear strain rate). In this paper, the effect of surface finish on the shear properties of various “microalloyed” SnAgCu-based solder materials was investigated. Individual solder joints were fabricated on a PCB with a solder mask defined configuration. A series of shear testing was conducted at four different strain rates of 0.001, 0.01, 0.1, and 1 s−1. Shear stress–strain curves were recorded for each test, and both shear strength and shear energy were measured. Following the shear testing, fractured top surfaces and cross sections were inspected using SEM/EDS microscopy to characterize the failure mechanism. The results showed that both shear strength and shear energy increase with increasing shear strain rate due to the viscoplasticity of the solder materials. Failure mode analysis indicated the existence of three failure mechanisms, including ductile failure, brittle failure, and mixed failure. Higher occurrence of brittle failure was observed when the shear strain rate is high regardless of surface finish. It was also found that the combination of solder alloy with high silver (Ag) and bismuth (Bi) content and electroless Ni/immersion Au (ENIG) surface finish is more susceptible to brittle failure compared to the rest of solder alloy-surface finish combinations. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
43. 基于BGA 互联的毫米波模块三维集成设计.
- Author
-
周江, 张先荣, and 钟丽
- Abstract
Copyright of Telecommunication Engineering is the property of Telecommunication Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2019
- Full Text
- View/download PDF
44. Head-on-Pillow Defect Detection: X-Ray Inspection Limitations.
- Author
-
Bruno, Lars and Gustafson, Benny
- Subjects
- *
BALL grid array technology , *SOLDER joints , *SYSTEM-in-a-package , *SOLDER pastes , *HALIDES - Abstract
Both the number and the variants of ball grid array packages (BGAs) are tending to increase on network printed board assemblies with sizes ranging from a few millimeter die size wafer level packages with low ball count to large multidie system-inpackage (SiP) BGAs with 60-70mmside lengths and thousands of I/Os. One big challenge, especially for large BGAs, SiPs, and for thin fine-pitch BGA assemblies, is the dynamic warpage during the reflow soldering process. This warpage could lead to solder balls losing contact with the solder paste and its flux during parts of the soldering process, and this may result in solder joints with irregular shapes, indicating poor or no coalescence between the added solder and the BGA balls. This defect is called head-on-pillow (HoP) and is a failure type that is difficult to determine. In this study, x-ray inspection was used as a first step to find deliberately induced HoP defects, followed by prying off of the BGAs to verify real HoP defects and the fault detection correlation between the two methods. The result clearly shows that many of the solder joints classified as potential HoP defects in the x-ray analysis have no evidence at all of HoP after pry-off. This illustrates the difficulty of determining where to draw the line between pass and fail for HoP defects when using x-ray inspection. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
45. Off-target phenotypes in forensic DNA phenotyping and biogeographic ancestry inference: A resource.
- Author
-
Bradbury, Cedric, Köttgen, Anna, and Staubach, Fabian
- Subjects
SINGLE nucleotide polymorphisms ,HUMAN phenotype ,DNA fingerprinting ,NUCLEOTIDE sequencing ,DNA analysis - Abstract
Graphical abstract Health related off-target-phenotypes (OTPs) associated with SNP (single nucleotide polymorphism) markers used in forensic DNA phenotyping (FDP) and biogeographic ancestry inference (BGA). Highlights • 27 of 1766 SNPs used in FDP and BGA reveal health-related information. • Effect sizes for a small subset of the SNPs are considerable. • Off-target phenotypes: disposition to develop cancer, alcohol dependence, asthma. • We provide a list of off-target associations of BGA and FDP SNPs as a resource. Abstract With recent advances in DNA sequencing technologies it has become feasible and cost effective to genotype larger marker sets for forensic purposes. Two technologies that make use of the larger marker sets have come into focus in forensic research and applications; inference of biogeographic ancestry (BGA) and forensic DNA phenotyping (FDP). These methods hold the promise to reveal information about a yet unknown perpetrator from a DNA sample. In contrast, DNA-profiling, that is a standard practice in case work, relies on matching DNA-profiles between crime scene material and suspects on a database of DNA-profiles. Markers for DNA-profiling were developed under the premise to reveal as little additional information about the human source of the profile as possible, the rationale being that personal privacy rights have to be balanced against the public interest in solving a crime. The same argument holds for markers used in BGA and FDP; these markers might also reveal information on off-target phenotypes (OTPs), that go beyond BGA and the phenotypes targeted in FDP. In particular, health related OTPs might shift the balance between privacy protection and public interest. However, to our knowledge, there is currently no convenient resource available to incorporate knowledge on OTPs in BGA and FDP assay design and application. In order to provide such a resource, we performed a systematic search for OTPs associated with a comprehensive set of markers (1766 SNPs) used or suggested to be used for BGA inference and FDP. In this set, we identified a relatively small number of 27 SNPs (1.53%) that convey information on diverse health related OTPs such as cancer risk, induced asthma, or risk of alcoholism. Some of these SNPs are commonly used for FDP and BGA across different marker sets. We conclude that the effects of SNP markers used in FDP and BGA on OTPs are currently limited, with few exceptions that should be considered in a balanced decision on assay design and application. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
46. Fatigue performance and microstructure of lead-free solder joints in BGA assembly at room temperature.
- Author
-
Wei, Xin, Hamasha, Sa'd, Alahmer, Ali, Belhadi, Mohamed El Amine, and Vyas, Palash Pranav
- Subjects
- *
LEAD-free solder , *SOLDER joints , *ALLOY fatigue , *SOLDER & soldering , *FAILURE mode & effects analysis , *SURFACE finishing , *COPPER-tin alloys - Abstract
One of the crucial factors in evaluating the reliability of an electronic appliance is fatigue failure of the interconnecting solder joints. In most situations, large bulk samples are used to investigate the fatigue characteristics of the solder materials. Only a few studies have examined the solder joints frequently observed in ball grid array (BGA) components. This study implemented a specialized test vehicle in BGA assembly connecting two substrates with nine identical solder joints. Four SAC-based solder alloys were tested using an Instron micromechanical tester in the stress-controlled and strain-controlled methods at room temperature and constant strain rate. At two distinctive stress and strain levels, the fatigue performance of alloys featuring organic solderability preservative (OSP) and electroless nickel-immersion gold (ENIG) surface finishes was investigated. The fatigue results obtained from the stress-controlled and strain-controlled tests were compared. Microstructural analysis was performed using scanning Electron Microscopy (SEM) and energy dispersive spectroscopy (EDS) to identify the precipitates in the bulk solder and the morphologies of IMC layers. The thickness of intermetallic compound (IMC) layers and the failure mode were examined in each case. The results demonstrated that the OSP surface finish significantly outperformed the ENIG surface finish regardless of the testing process and solder alloy. Various failure modes were observed, depending on the solder alloy and IMC layer. • Fatigue of solder joints in BGA was tested in stress and strain-controlled. • Microstructural analysis was performed using SEM/EDS. • The OSP surface finish outperformed the ENIG surface finish. • The interfacial IMC layer of SAC305 with the OSP surface finish was scallop-like • SAC-Q and SAC-I have a brittle failure mode featured with the ENIG finish. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
47. Design of multiprobe devices for electronic components with ball leads testing.
- Author
-
Nevlyudov I. Sh., Palagin V. A., Razumov-Frizyuk E. A., and Zharikova I. V.
- Subjects
electronic components ,BGA ,multiprobe connecting device ,testing ,contacting ,flexible PCB ,polyimide ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 - Abstract
In the article design and technological features of multiprobe connecting device for testing the electronic components with matrix ball leads are described and substantiated. Such test fixture has probes made as two separated flatcontact lands that can be used for testing BGA/CSP components or microelectromechanical devices. Only in case, when two parts of probe contact lands are pressed to according lead of electronic component, electrical circuit between them closes. This fact confirms presence of contact between testing fixture probe and tested lead of BGA device and can be considered as way of testing reliability increasing. Due to the proposed new form of contact probe for electronic component testing it became possible to simplify the topology of connecting circuit board. Developed commutative board with ZIF connectors allows realizing multiprobe device connection to automated measuring systems, providing also the possibility of its future application to test other electronic components with more leads. Also the results of experimental and modeling research of developed device prototype are presented and explained. Obtained results substantiate the basic requirements for the multiprobe connecting device that should be observed during its contacting to the unit under test. Designed test fixture is more simple and cheap in comparison with its analogues. Also developed method of testing effectively provides the necessary contact pressure between test fixture and unit under test without hazard of its deformation which can appear in similar devices.
- Published
- 2016
- Full Text
- View/download PDF
48. Thermo-Fluidic Characterizations of Multi-Port Compact Thermal Model of Ball-Grid-Array Electronic Package
- Author
-
Valentin Bissuel, Frédéric Joly, Eric Monier-Vinard, Alain Neveu, and Olivier Daniel
- Subjects
BCI-DCTM ,ROM ,modal approach ,BGA ,experimental validation ,Technology - Abstract
The concept of a single-input/multi-output thermal network was proposed by the Development of Libraries of Physical models for an Integrated design environment (DELPHI) consortium more than twenty years ago. The present work highlights the recent improvements made to efficiently derive a low-computing-effort model from a fully detailed numerical model and to characterize its performances. The temperature predictions of a deduced ball-grid-array (BGA) dynamic compact thermal model are compared to those of a realistic three-dimensional representation, including the large set of internal copper traces, as well as its board structure, which has been validated by experiment. The current study discloses a method for creating an amalgam reduced-order modal model (AROMM) for that electronic component family that allows the preservation of the geometry integrity and shortening scenarios computation. Typically, the AROMM method reduces by a factor of 600 the computation time needed to obtain the solution while keeping the error on the maximum temperature below 2%. Then, a meta-heuristic optimization is run to derive a more practical low-order resistor capacitor model that enables a thermo-fluidic analysis at the board level. Based on the calibrated numerical model, a novel AROMM method was investigated in order to address the chip behavior submitted to multiple heat sources. The first results highlight the capability to enforce a non-uniform power distribution on the upper surface of the silicon chip. Thus, the chip design layout can be analyzed and optimized to prevent thermal and reliability issues.
- Published
- 2020
- Full Text
- View/download PDF
49. Failure Analysis of SAC305 Ball Grid Array Solder Joint at Extremely Cryogenic Temperature
- Author
-
Yanruoyue Li, Guicui Fu, Bo Wan, Maogong Jiang, Weifang Zhang, and Xiaojun Yan
- Subjects
sac305 ,bga ,low temperature ,fracture failure ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
To verify the reliability of a typical Pb-free circuit board applied for space exploration, five circuits were put into low temperature and shock test. However, after the test, memories on all five circuits were out of function. To investigate the cause of the failure, a series of methods for failure analysis was carried out, including X-ray detection, cross-section analysis, Scanning Electron Microscope (SEM) analysis, and contrast test. Through failure analysis, the failure was located in the Pb-free (Sn-3.0Ag-0.5Cu) solder joint, and we confirmed that the failure occurred because of the low temperature and change of fracture characteristic of Sn-3.0Ag-0.5Cu (SAC305). A verification test was conducted to verify the failure mechanism. Through analyzing data and fracture surface morphology, the cause of failure was ascertained. At low temperature, the fracture characteristic of SAC305 changed from ductileness to brittleness. The crack occurred at solder joints because of stress loaded by shock test. When the crack reached a specific length, the failure occurred. The temperature of the material’s characteristic change was −70−−80 °C. It could be a reference for Pb-free circuit board use in a space environment.
- Published
- 2020
- Full Text
- View/download PDF
50. BGA Device Detection System Based on Frame Integral Reducing Noise Method
- Author
-
Zhang, Wen, Zhang, Xin Long, and Deng, Wei, editor
- Published
- 2012
- Full Text
- View/download PDF
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