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Bonding and Failure Mechanisms of Sintered-silver Die-attach on Electroless Nickel (Phosphorus) Surface Finish for Packaging Power Electronics Modules

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IEEE Transactions on Power Electronics 2024年

作者： Wang, Meiyu Zhang, Haobo Hu, Weibo Mei, Yunhui Lu, Guo-Quan Nankai University College of Electronic Information and Optical Engineering Tianjin300350 China Shenzhen research institute of Nankai University Shenzhen518083 China Nankai University Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology Tianjin300350 China Tiangong University School of Electrical Engineering Tianjin300387 China The Bradley Department of Electrical and Computer Engineering The Department of Materials Science and Engineering BlacksburgVA24061 United States

The low-temperature silver sintering technology has been increasingly applied for die-attach in power electronics modules. Most reported studies of the technology involved bonding on silver (Ag) or gold (Au) surface finish. Compared to Ag or Au, electroless nickel (phosphorus) or Ni(P) is a cost-effective and widely-used process for surface-finishing module substrates. However, there is a lack of studies on sintered-Ag bonding on the Ni(P) surface. In this study, IGBT devices were bonded using pressureless Ag-sintering on electroless Ni(P)-plated substrates. Micro-morphologies and macro-properties were then characterized before and after three reliability tests including high temperature storage life (HTSL), steady-state temperature-humidity bias life (STHBL), and temperature cycling (TC) tests. The as-sintered joints measured strong adhesion of 39 MPa, resulting from Ag-NiO-Ni chemical bonds across the (111) crystal planes with reduced lattice misfit. The Ag-Ni(P) joints exhibited high reliability under high-temperature and thermo-mechanical stress in the HTSL and TC tests, but performed poorly when exposed to high humidity in the STHBL test. The founding in this study helps understand the physical nature of bonding between sintered-Ag and Ni(P), and its failure mechanisms under the influence of different physical stresses. © 1986-2012 IEEE.

关键词： Bond strength (chemical)

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Phong shading approximation of computer-generated holography based on fully analytical triangle meshes

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Chinese Optics Letters 2025年第4期 6-13页

作者：邹茜符庆杨刘燕杨敏王品张亚萍潘定中 School of Physics and Electronic Information Yunnan Normal University Smart Computational Imaging Laboratory SCILab School of Electronic and Optical Engineering Nanjing University of Science and Technology Yunnan Provincial Key Laboratory of Modern Information Optics LMIO Kunming University of Science and Technology Bradley Department of Electrical and Computer Engineering Virginia Tech

We propose a Phong shading approximation,which gives the amplitude of each point inside the triangle through linear interpolation within the framework of self-similarity segmentation and affine transformation in polygon-based computer-generated *** is important as it reflects the geometric properties of the *** accurately represent the geometric properties of objects in three-dimensional space,the method involves calculating the amplitude distribution on each triangle and maintaining a complete analytical framework,with the edges of the reconstructed polygons nearly *** simulations and optical reconstructions demonstrate that the proposed method successfully addresses the issue of edge discontinuity on polygonal surfaces.

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Holographic performances of graphene oxide photopolymer [Invited] 10

Holographic performances of graphene oxide photopolymer [Inv...

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Holography, Diffractive Optics, and Applications X 2020

作者： Zhang, Yaping Zhu, Xufeng Poon, Ting-Chung Key Laboratory of Laser Information Processing Technology and Application Kunming University of Science and Technology Kunming650500 China Bradley Department of Electrical and Computer Engineering Virginia Tech BlacksburgVA24061 United States

ISBN: (纸本)9781510639171

Graphene oxide (GO) is a precursor material for producing graphene. The electrical and optical properties of GO can be modified by reduction of the oxygen-containing groups. In this report, we have prepared graphene oxide polymers (GO-polymer) with different vol. % of GO and reduced the polymer by direct laser writing. We have found the refractive indexmodulation ofthe GO-polymerup to for15 vol.%. © 2020 SPIE.

关键词： Graphene

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1D quasi-bound states in the continuum with large operation bandwidth in theω~k space for nonlinear optical applications

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Photonics Research 2022年第7期10卷 1575-1581页

作者： KAILI SUN HUI JIANG DMITRY ABYKOV VIEN VAN URIEL LEVY YANGJIAN CAI ZHANGHUA HAN Shandong Provincial Key Laboratory of Optics and Photonic Devices Center of Light Manipulation and ApplicationsSchool of Physics and ElectronicsShandong Normal UniversityJinan 250358China Image Processing Systems Institute—Branch of the Federal Scientific Research Centre“Crystallography and Photonics”of Russian Academy of Sciences Samara 443001Russia Department of Electrical and Computer Engineering University of AlbertaEdmontonAlberta T6G 2V4Canada Department of Applied Physics and Center for Nanoscience and NanotechnologyThe Hebrew University of JerusalemJerusalemIsrael

The phenomenon of bound state in the continuum(BIC)with an infinite quality factor and lifetime has emerged in recent years in photonics as a new tool to manipulate light-matter ***,most of the investigated structures only support BIC resonances at very few discrete points in theω~k *** when the BIC is switched to a quasi-BIC(QBIC)resonance through perturbation,its frequency will still be located within a narrow spectral band close to that of the original BIC,restricting their applications in many fields where random or multiple input frequencies beyond the narrow band are *** this work,we demonstrate that a new set of QBIC resonances can be supported by using a special binary grating consisting of two alternatingly aligned ridge arrays with the same period and zero-approaching ridge width difference on a slab *** QBIC resonances are distributed continuously over a broad band along a line in theω~k space and can thus be considered as 1 D *** the Q factors generally affected by the ridge difference,it is now possible to arbitrarily choose any frequencies on the dispersion line to achieve significantly enhanced light-matter interactions,facilitating many applications where multiple input wavelengths are required;e.g.,sum or difference frequency generations in nonlinear optics.

关键词： quasi nonlinear narrow

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One-dimensional quasi bound states in the continuum with large operation bandwidth in the ω~k space for nonlinear optical applications

arXiv

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arXiv 2022年

作者： Sun, Kaili Jiang, Hui Bykov, Dmitry A. Van, Vien Levy, Uriel Cai, Yangjian Han, Zhanghua Shandong Provincial Key Laboratory of Optics and Photonic Devices Center of Light Manipulation and Applications School of Physics and Electronics Shandong Normal University Jinan250358 China Image Processing Systems Institute Branch of the Federal Scientific Research Centre "Crystallography and Photonics" Russian Academy of Sciences 151 Molodogvardeyskaya st. Samara443001 Russia Department of Electrical and Computer Engineering University of Alberta EdmontonT6G 2V4 Canada Department of Applied Physics The center for Nanoscience and Nanotechnology The Hebrew University of Jerusalem Jerusalem Israel

The phenomenon of bound state in the continuum (BIC) with infinite quality factor and lifetime has emerged in recent years in photonics as a new tool of manipulating light-matter interactions. However, most of the investigated structures only support BIC resonances at very few discrete points in the ω~k space. Even when the BIC is switched to a quasi-BIC(QBIC) resonance through perturbation, its frequency will still be located within a narrow spectral band close to that of the original BIC, restricting their applications in many fields where random or multiple input frequencies beyond the narrow band are required. In this work, we demonstrate that a new set of QBIC resonances can be supported by making use of a special binary grating consisting of two alternatingly aligned ridge arrays with the same period and zero-approaching ridge width difference on a slab waveguide. These QBIC resonances are distributed continuously over a broad band along a line in the ω~k space and can thus be considered as one-dimensional QBICs. With the Q factors generally affected by the ridge difference, it is now possible to choose arbitrarily any frequencies on the dispersion line to achieve significantly enhanced light-matter interactions, facilitating many applications where multiple input wavelengths are required, e.g. sum or difference frequency generations in nonlinear optics. Copyright © 2022, The Authors. All rights reserved.

关键词： Resonance

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Annular pupil in optical scanning holography

Annular pupil in optical scanning holography

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2019 Conference on Digital Holography and Three-Dimensional Imaging, DH 2019

作者： Zhang, Yaping Wang, Rende Wang, Lin Tsang, Peter Poon, T.-C. Key Lab of Laser Information Processing Technology and Application Kunming University of Science and Technology Kunming650500 China School of Electronic and Optical Engineering Nanjing University of Science and Technology Nanjing Jiangsu210094 China Department of Electronic Engineering City University of Hong Kong 83 Tat Chee Avenue Kowloon Hong Kong Bradley Department of Electrical and Computer Engineering Virginia Tech BlacksburgVA24061 United States

optical scanning holography (OSH) is a variant of two-pupil heterodyning image processing. We investigate the use of one pupil as a delta function and the other being an annulus as an extended application of OSH. ... 详细信息

ISBN: (纸本)9781943580590

关键词： Holography

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AIM 2019 challenge on real-world image super-resolution: Methods and results

arXiv

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arXiv 2019年

作者： Lugmayr, Andreas Danelljan, Martin Timofte, Radu Fritsche, Manuel Gu, Shuhang Purohit, Kuldeep Kandula, Praveen Suin, Maitreya Rajagopalan, A.N. Joon, Nam Hyung Won, Yu Seung Kim, Guisik Kwon, Dokyeong Hsu, Chih-Chung Lin, Chia-Hsiang Huang, Yuanfei Sun, Xiaopeng Lu, Wen Li, Jie Gao, Xinbo Bell-Kligler, Sefi Computer Vision Lab ETH Zurich Indian Institute Of Technology Madras India Image Communication & Signal Processing Laboratory Hanyang University Seoul Korea Republic of CVML Chung-Ang University Department Management Information Systems National Pingtung University of Science and Technology Department of Electrical Engineering National Cheng-Kung University Xidian University Weizmann Institute of Science Israel

This paper reviews the AIM 2019 challenge on real world super-resolution. It focuses on the participating methods and final results. The challenge addresses the real world setting, where paired true high and low-resolution images are unavailable. For training, only one set of source input images is therefore provided in the challenge. In Track 1: Source Domain the aim is to super-resolve such images while preserving the low level image characteristics of the source input domain. In Track 2: Target Domain a set of high-quality images is also provided for training, that defines the output domain and desired quality of the superresolved images. To allow for quantitative evaluation, the source input images in both tracks are constructed using artificial, but realistic, image degradations. The challenge is the first of its kind, aiming to advance the state-of-the-art and provide a standard benchmark for this newly emerging task. In total 7 teams competed in the final testing phase, demonstrating new and innovative solutions to the problem. Copyright © 2019, The Authors. All rights reserved.

关键词： optical resolving power

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Efficient T2 mapping with Blip-up/down EPI and gSlider-SMS (T2-BUDA-gSlider)

arXiv

引用

arXiv 2019年

作者： Cao, Xiaozhi Liao, Congyu Zhang, Zijing Iyer, Siddharth Srinivasan Chen, Zhifeng Lo, Wei-Ching Liu, Huafeng Wang, Kang He, Hongjian Setsompop, Kawin Zhong, Jianhui Bilgic, Berkin Center for Brain Imaging Science and Technology Department of Biomedical Engineering Zhejiang University Zhejiang Hangzhou China Athinoula A. Martinos Center for Biomedical Imaging Massachusetts General Hospital CharlestownMA United States Department of Radiology Harvard Medical School CharlestownMA United States State Key Laboratory of Modern Optical Instrumentation College of Optical Science and Engineering Zhejiang University Zhejiang Hangzhou China Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology CambridgeMA United States School of Biomedical Engineering Guangdong Provincial Key Laboratory of Medical Image Processing Southern Medical University Guangzhou China Siemens Medical Solutions BostonMA United States Department of Neurology The First Affiliated Hospital School of Medicine Zhejiang University Hangzhou China Harvard-MIT Department of Health Sciences and Technology CambridgeMA United States Department of Imaging Sciences University of Rochester NY United States

Purpose: To rapidly obtain high isotropic-resolution T2 maps with whole-brain coverage and high geometric fidelity. Methods: A T2 blip-up/down echo planar imaging (EPI) acquisition with generalized Slice-dithered enhanced resolution (T2-BUDA-gSlider) is proposed. A radiofrequency (RF)-encoded multi-slab spin-echo EPI acquisition with multiple echo times (TEs) was developed to obtain high SNR efficiency with reduced repetition time (TR). This was combined with an interleaved 2-shot EPI acquisition using blip-up/down phase encoding. An estimated field map was incorporated into the joint multi-shot EPI reconstruction with a structured low rank constraint to achieve distortion-free and robust reconstruction for each slab without navigation. A Bloch simulated subspace model was integrated into gSlider reconstruction and utilized for T2 quantification. Results: In vivo results demonstrated that the T2 values estimated by the proposed method were consistent with gold standard spin-echo acquisition. Compared to the reference 3D fast spin echo (FSE) images, distortion caused by off-resonance and eddy current effects were effectively mitigated. Conclusion: BUDA-gSlider SE-EPI acquisition and gSlider-subspace joint reconstruction enabled distortion-free whole-brain T2 mapping in 2 min at ~1 mm3 isotropic resolution, which could bring significant benefits to related clinical and neuroscience applications. Copyright © 2019, The Authors. All rights reserved.

关键词： Spin polarization

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Deep learning enabled fast optical characterization of two-dimensional materials

arXiv

引用

arXiv 2019年

作者： Han, Bingnan Lin, Yuxuan Yang, Yafang Mao, Nannan Li, Wenyue Wang, Haozhe Fatemi, Valla Zhou, Lin Wang, Joel I-Jan Ma, Qiong Cao, Yuan Rodan-Legrain, Daniel Bie, Ya-Qing Navarro-Moratalla, Efrén Klein, Dahlia MacNeill, David Wu, Sanfeng Leong, Wei Sun Kitadai, Hikari Ling, Xi Jarillo-Herrero, Pablo Palacios, Tomás Yin, Jihao Kong, Jing Image Processing Center School of Astronautics Beihang University Beijing100191 China Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology CambridgeMA02139 United States Department of Physics Massachusetts Institute of Technology CambridgeMA02139 United States Department of Chemistry Boston University BostonMA02215 United States Research Laboratory of Electronics Massachusetts Institute of Technology CambridgeMA02139 United States Instituto de Ciencia Molecular Universidad de Valencia c/Catedrático José Beltrán 2 Paterna46980 Spain Division of Materials Science and Engineering Boston University BostonMA02215 United States

Characterization of nanomaterial morphologies with advanced microscopy and/or spectroscopy tools plays an indispensable role in nanoscience and nanotechnology research 1 2, 3, 4, 5, as rich information about the chemical compositions, crystallography, other physical and chemical properties, as well as the growth mechanism can be extracted from morphology analysis. However, the interpretation of imaging data heavily relies on the "intuition" of experienced researchers. As a result, many of the deep graphical features are often unused because of difficulties in processing the data and finding the correlations. Such difficulties can be well addressed by deep learning 6 7, 8, 9. In this work, we use the optical characterization of two-dimensional (2D) materials as a case study, and demonstrate a neural network based algorithm for the material and thickness identification of exfoliated 2D materials with high prediction accuracy and real-time processing capability. Further analysis shows that the trained network can be used to predict physical properties of the materials. Finally, a transfer learning technique is applied to adapt the pretrained network to more optical characterization applications such as identifying layer numbers of chemically synthesized graphene domains. Copyright © 2019, The Authors. All rights reserved.

关键词： Data handling

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Quantum-optimal detection of one-versus-two incoherent optical sources with arbitrary separation

arXiv

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arXiv 2018年

作者： Lu, Xiao-Ming Krovi, Hari Nair, Ranjith Guha, Saikat Shapiro, Jerey H. Department of Physics Hangzhou Dianzi University Hangzhou310018 China Department of Electrical and Computer Engineering National University of Singapore 4 Engineering Drive 3 Singapore117583 Singapore Quantum Information Processing Group Raytheon Bbn Technologies CambridgeMA02138 United States College of Optical Sciences University of Arizona TucsonAZ85719 United States Research Laboratory of Electronics Massachusetts Institute of Technology CambridgeMA02139 United States

We analyze the fundamental quantum limit of the resolution of an optical imaging system from the perspective of the detection problem of deciding whether the optical field in the image plane is generated by one incoherent on-axis source with brightness uras that are symmetrically disposed about the optical axis. Using the exact thermal-state model of the field, we derive the quantum Chernoff bound for the detection problem, which specifies the optimum rate of decay of the error probability with increasing number of collected photons that is allowed by quantum mechanics. We then show that recently proposed linear-optic schemes approach the quantum Chemolf bound-the method of binary spatial-mode demultiplexing (B-SPADE) is quantum-optimal for all values of separation, while a method using image-inversion interferometry (SLIVER) is near-optimal for sub-Rayleigh separations. We then simplify our model using a low-brightness approximation that is very accurate for optical microscopy and astronomy, derive quantum Chernoff bounds conditional on the number of photons detected, and show the optimality of our schemes in this conditional detection paradigm. For comparison, we analytically demonstrate the superior scaling of the Chernoff bound for our schemes with source separation relative to that of spatially-resolved direct imaging. Our schemcs have the advantages over the quantum-optimal (Helstrom) measurement in that they do not involve joint measurements over multiple modes, and that they do not require the angular separation for the two-source hypothesis to be given a prion and can offer that information 3s a bonus in the event of a successful detection. Copyright © 2018, The Authors. All rights reserved.

关键词： Luminance

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