Subjects -> ENGINEERING (Total: 2791 journals)
    - CHEMICAL ENGINEERING (248 journals)
    - CIVIL ENGINEERING (242 journals)
    - ELECTRICAL ENGINEERING (176 journals)
    - ENGINEERING (1402 journals)
    - ENGINEERING MECHANICS AND MATERIALS (452 journals)
    - HYDRAULIC ENGINEERING (56 journals)
    - INDUSTRIAL ENGINEERING (100 journals)
    - MECHANICAL ENGINEERING (115 journals)

ENGINEERING (1402 journals)                  1 2 3 4 5 6 7 8 | Last

Showing 1 - 200 of 1205 Journals sorted alphabetically
3 Biotech     Open Access   (Followers: 2)
3D Research     Hybrid Journal   (Followers: 17)
AAPG Bulletin     Hybrid Journal   (Followers: 9)
Abstract and Applied Analysis     Open Access   (Followers: 1)
Aceh International Journal of Science and Technology     Open Access   (Followers: 3)
ACS Nano     Hybrid Journal   (Followers: 189)
Acta Geotechnica     Hybrid Journal   (Followers: 6)
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 8)
Acta Nova     Open Access  
Acta Polytechnica : Journal of Advanced Engineering     Open Access  
Acta Universitatis Cibiniensis. Technical Series     Open Access   (Followers: 1)
Active and Passive Electronic Components     Open Access   (Followers: 5)
Additive Manufacturing Letters     Open Access   (Followers: 6)
Adsorption     Hybrid Journal   (Followers: 4)
Advanced Energy and Sustainability Research     Open Access   (Followers: 4)
Advanced Engineering Forum     Full-text available via subscription   (Followers: 10)
Advanced Engineering Research     Open Access  
Advanced Journal of Graduate Research     Open Access   (Followers: 1)
Advanced Quantum Technologies     Hybrid Journal   (Followers: 1)
Advanced Science     Open Access   (Followers: 12)
Advanced Science Focus     Free   (Followers: 5)
Advanced Science Letters     Full-text available via subscription   (Followers: 9)
Advanced Science, Engineering and Medicine     Partially Free   (Followers: 3)
Advanced Synthesis & Catalysis     Hybrid Journal   (Followers: 19)
Advanced Theory and Simulations     Hybrid Journal   (Followers: 2)
Advances in Applied Energy     Open Access   (Followers: 5)
Advances in Catalysis     Full-text available via subscription   (Followers: 7)
Advances in Complex Systems     Hybrid Journal   (Followers: 10)
Advances in Engineering Software     Hybrid Journal   (Followers: 25)
Advances in Fuzzy Systems     Open Access   (Followers: 5)
Advances in Geosciences (ADGEO)     Open Access   (Followers: 19)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 27)
Advances in Natural Sciences : Nanoscience and Nanotechnology     Open Access   (Followers: 28)
Advances in Operations Research     Open Access   (Followers: 13)
Advances in OptoElectronics     Open Access   (Followers: 6)
Advances in Physics Theories and Applications     Open Access   (Followers: 12)
Advances in Polymer Science     Hybrid Journal   (Followers: 50)
Advances in Remote Sensing     Open Access   (Followers: 58)
Advances in Science and Research (ASR)     Open Access   (Followers: 8)
Aerobiologia     Hybrid Journal   (Followers: 2)
Aerospace Systems     Hybrid Journal   (Followers: 7)
African Journal of Science, Technology, Innovation and Development     Hybrid Journal   (Followers: 7)
AIChE Journal     Hybrid Journal   (Followers: 31)
Ain Shams Engineering Journal     Open Access   (Followers: 1)
Al-Nahrain Journal for Engineering Sciences     Open Access  
Al-Qadisiya Journal for Engineering Sciences     Open Access  
AL-Rafdain Engineering Journal     Open Access  
Alexandria Engineering Journal     Open Access   (Followers: 1)
AMB Express     Open Access   (Followers: 1)
American Journal of Applied Sciences     Open Access   (Followers: 21)
American Journal of Engineering and Applied Sciences     Open Access   (Followers: 7)
American Journal of Engineering Education     Open Access   (Followers: 13)
American Journal of Environmental Engineering     Open Access   (Followers: 6)
American Journal of Industrial and Business Management     Open Access   (Followers: 23)
Annals of Civil and Environmental Engineering     Open Access   (Followers: 1)
Annals of Combinatorics     Hybrid Journal   (Followers: 3)
Annals of Pure and Applied Logic     Open Access   (Followers: 4)
Annals of Regional Science     Hybrid Journal   (Followers: 7)
Annals of Science     Hybrid Journal   (Followers: 9)
Annual Journal of Technical University of Varna     Open Access  
Antarctic Science     Hybrid Journal   (Followers: 1)
Applicable Algebra in Engineering, Communication and Computing     Hybrid Journal   (Followers: 3)
Applicable Analysis: An International Journal     Hybrid Journal   (Followers: 1)
Applications in Energy and Combustion Science     Open Access   (Followers: 2)
Applications in Engineering Science     Open Access  
Applied Catalysis A: General     Hybrid Journal   (Followers: 7)
Applied Catalysis B: Environmental     Hybrid Journal   (Followers: 9)
Applied Clay Science     Hybrid Journal   (Followers: 6)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 16)
Applied Energy     Partially Free   (Followers: 25)
Applied Engineering Letters     Open Access  
Applied Magnetic Resonance     Hybrid Journal   (Followers: 3)
Applied Nanoscience     Open Access   (Followers: 7)
Applied Network Science     Open Access   (Followers: 2)
Applied Numerical Mathematics     Hybrid Journal   (Followers: 4)
Applied Physics Research     Open Access   (Followers: 5)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 5)
Arab Journal of Basic and Applied Sciences     Open Access  
Arabian Journal for Science and Engineering     Hybrid Journal   (Followers: 1)
Archives of Computational Methods in Engineering     Hybrid Journal   (Followers: 5)
Archives of Foundry Engineering     Open Access  
Archives of Thermodynamics     Open Access   (Followers: 10)
Arctic     Open Access  
Arid Zone Journal of Engineering, Technology and Environment     Open Access  
ArtefaCToS : Revista de estudios sobre la ciencia y la tecnología     Open Access  
Asian Journal of Applied Science and Engineering     Open Access  
Asian Journal of Applied Sciences     Open Access   (Followers: 2)
Asian Journal of Biotechnology     Open Access   (Followers: 8)
Asian Journal of Control     Hybrid Journal  
Asian Journal of Technology Innovation     Hybrid Journal   (Followers: 5)
Assembly Automation     Hybrid Journal   (Followers: 2)
ATZagenda     Hybrid Journal  
ATZextra worldwide     Hybrid Journal  
AURUM : Mühendislik Sistemleri ve Mimarlık Dergisi = Aurum Journal of Engineering Systems and Architecture     Open Access   (Followers: 1)
Australasian Journal of Engineering Education     Hybrid Journal   (Followers: 3)
Australasian Physical & Engineering Sciences in Medicine     Hybrid Journal   (Followers: 1)
Australian Journal of Multi-Disciplinary Engineering     Hybrid Journal  
Autocracy : Jurnal Otomasi, Kendali, dan Aplikasi Industri     Open Access  
Automotive and Engine Technology     Hybrid Journal  
Automotive Experiences     Open Access  
Automotive Innovation     Hybrid Journal  
Avances en Ciencias e Ingenierías     Open Access  
Avances: Investigación en Ingeniería     Open Access  
Balkan Region Conference on Engineering and Business Education     Open Access   (Followers: 2)
Bangladesh Journal of Scientific and Industrial Research     Open Access  
Basin Research     Hybrid Journal   (Followers: 6)
Batteries     Open Access   (Followers: 8)
Batteries & Supercaps     Hybrid Journal   (Followers: 5)
Bautechnik     Hybrid Journal   (Followers: 1)
Bell Labs Technical Journal     Hybrid Journal   (Followers: 27)
Beni-Suef University Journal of Basic and Applied Sciences     Open Access  
Beyond : Undergraduate Research Journal     Open Access  
Bhakti Persada : Jurnal Aplikasi IPTEKS     Open Access  
Bharatiya Vaigyanik evam Audyogik Anusandhan Patrika (BVAAP)     Open Access  
Bilge International Journal of Science and Technology Research     Open Access   (Followers: 1)
Biointerphases     Open Access   (Followers: 1)
Biomaterials Science     Hybrid Journal   (Followers: 11)
Biomedical Engineering     Hybrid Journal   (Followers: 11)
Biomedical Engineering Letters     Hybrid Journal   (Followers: 3)
Biomedical Engineering: Applications, Basis and Communications     Hybrid Journal   (Followers: 4)
Biomedical Microdevices     Hybrid Journal   (Followers: 8)
Biomedical Science and Engineering     Open Access   (Followers: 4)
Biomicrofluidics     Open Access   (Followers: 7)
Biotechnology Progress     Hybrid Journal   (Followers: 42)
Black Sea Journal of Engineering and Science     Open Access  
Botswana Journal of Technology     Full-text available via subscription   (Followers: 1)
Boundary Value Problems     Open Access  
Bulletin of Canadian Petroleum Geology     Full-text available via subscription   (Followers: 12)
Bulletin of Engineering Geology and the Environment     Hybrid Journal   (Followers: 15)
Cahiers Droit, Sciences & Technologies     Open Access   (Followers: 1)
Calphad     Hybrid Journal  
Canadian Geotechnical Journal     Hybrid Journal   (Followers: 28)
Canadian Journal of Remote Sensing     Full-text available via subscription   (Followers: 51)
Carbon Resources Conversion     Open Access   (Followers: 2)
Carpathian Journal of Electronic and Computer Engineering     Open Access  
Case Studies in Thermal Engineering     Open Access   (Followers: 9)
Catalysis Communications     Hybrid Journal   (Followers: 7)
Catalysis Letters     Hybrid Journal   (Followers: 3)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 9)
Catalysis Science and Technology     Hybrid Journal   (Followers: 9)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 4)
Catalysis Today     Hybrid Journal   (Followers: 4)
CEAS Space Journal     Hybrid Journal   (Followers: 6)
Cell Reports Physical Science     Open Access  
Cellular and Molecular Neurobiology     Hybrid Journal   (Followers: 2)
CFD Letters     Open Access   (Followers: 7)
Chaos : An Interdisciplinary Journal of Nonlinear Science     Hybrid Journal   (Followers: 3)
Chaos, Solitons & Fractals     Hybrid Journal   (Followers: 1)
Chaos, Solitons & Fractals : X     Open Access   (Followers: 1)
Chinese Journal of Catalysis     Full-text available via subscription   (Followers: 2)
Chinese Journal of Engineering     Open Access   (Followers: 1)
Chinese Journal of Population, Resources and Environment     Open Access  
Chinese Science Bulletin     Open Access  
Ciencia e Ingenieria Neogranadina     Open Access  
Ciencia en su PC     Open Access   (Followers: 1)
Ciencia y Tecnología     Open Access  
Ciencias Holguin     Open Access   (Followers: 1)
CienciaUAT     Open Access  
Cientifica     Open Access  
CIRP Annals - Manufacturing Technology     Hybrid Journal   (Followers: 10)
CIRP Journal of Manufacturing Science and Technology     Hybrid Journal   (Followers: 12)
City, Culture and Society     Hybrid Journal   (Followers: 23)
Clay Minerals     Hybrid Journal   (Followers: 7)
Cleaner Engineering and Technology     Open Access   (Followers: 4)
Cleaner Environmental Systems     Open Access   (Followers: 4)
Coastal Engineering     Hybrid Journal   (Followers: 16)
Coastal Engineering Journal     Hybrid Journal   (Followers: 7)
Coastal Engineering Proceedings : Proceedings of the International Conference on Coastal Engineering     Open Access   (Followers: 1)
Coastal Management     Hybrid Journal   (Followers: 29)
Coatings     Open Access   (Followers: 2)
Cogent Engineering     Open Access   (Followers: 1)
Cognitive Computation     Hybrid Journal   (Followers: 2)
Color Research & Application     Hybrid Journal   (Followers: 1)
COMBINATORICA     Hybrid Journal  
Combustion Theory and Modelling     Hybrid Journal   (Followers: 18)
Combustion, Explosion, and Shock Waves     Hybrid Journal   (Followers: 21)
Communications Faculty of Sciences University of Ankara Series A2-A3 Physical Sciences and Engineering     Open Access  
Communications in Numerical Methods in Engineering     Hybrid Journal   (Followers: 2)
Components, Packaging and Manufacturing Technology, IEEE Transactions on     Hybrid Journal   (Followers: 27)
Composite Interfaces     Hybrid Journal   (Followers: 6)
Composite Structures     Hybrid Journal   (Followers: 246)
Composites Part A : Applied Science and Manufacturing     Hybrid Journal   (Followers: 179)
Composites Part B : Engineering     Hybrid Journal   (Followers: 224)
Composites Part C : Open Access     Open Access   (Followers: 1)
Composites Science and Technology     Hybrid Journal   (Followers: 151)
Comptes Rendus : Mécanique     Open Access   (Followers: 2)
Computation     Open Access   (Followers: 1)
Computational Geosciences     Hybrid Journal   (Followers: 17)
Computational Optimization and Applications     Hybrid Journal   (Followers: 9)
Computer Applications in Engineering Education     Hybrid Journal   (Followers: 6)
Computer Science and Engineering     Open Access   (Followers: 15)
Computers & Geosciences     Hybrid Journal   (Followers: 29)
Computers & Mathematics with Applications     Full-text available via subscription   (Followers: 8)
Computers and Electronics in Agriculture     Hybrid Journal   (Followers: 7)
Computers and Geotechnics     Hybrid Journal   (Followers: 11)
Computing and Visualization in Science     Hybrid Journal   (Followers: 6)
Computing in Science & Engineering     Full-text available via subscription   (Followers: 31)
Conciencia Tecnologica     Open Access  
Continuum Mechanics and Thermodynamics     Hybrid Journal   (Followers: 8)
Control Engineering Practice     Hybrid Journal   (Followers: 46)

        1 2 3 4 5 6 7 8 | Last

Similar Journals
Journal Cover
Components, Packaging and Manufacturing Technology, IEEE Transactions on
Journal Prestige (SJR): 0.482
Citation Impact (citeScore): 2
Number of Followers: 27  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Online) 2156-3950
Published by IEEE Homepage  [228 journals]
  • IEEE Transactions on Components, Packaging and Manufacturing Technology
           publication information

    • Free pre-print version: Loading...

      Abstract: Presents a listing of the editorial board, board of governors, current staff, committee members, and/or society editors for this issue of the publication.
      PubDate: Jan. 2022
      Issue No: Vol. 12, No. 1 (2022)
       
  • IEEE Components, Packaging, and Manufacturing Technology Society
           information for authors

    • Free pre-print version: Loading...

      Abstract: These instructions give guidelines for preparing papers for this publication. Presents information for authors publishing in this journal.
      PubDate: Jan. 2022
      Issue No: Vol. 12, No. 1 (2022)
       
  • IEEE Components, Packaging, and Manufacturing Technology Society
           Information

    • Free pre-print version: Loading...

      Abstract: Presents a listing of the editorial board, board of governors, current staff, committee members, and/or society editors for this issue of the publication.
      PubDate: Jan. 2022
      Issue No: Vol. 12, No. 1 (2022)
       
  • Modeling of the RF Coaxial TSV Configuration Inside the Silicon Interposer
           With Embedded Cooling Cavity

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      Authors: Wei Li;Zongxi Liu;Wenbing Qian;Zhenyu Wang;Wei Wang;Yongzhi Zhao;Xiaobin Zhang;
      Pages: 3 - 10
      Abstract: In this article, a low-loss RF coaxial through-silicon vias (TSVs) (C-TSVs) configuration in the silicon interposer with the embedded cooling cavity is proposed. For the single C-TSV array passing through the embedded cooling cavity, the transmission losses with different coolants were compared. The insertion loss immersed in FC770 is 0.14 dB at 40 GHz, which is closed to the typical C-TSV interposer (0.2 dB). It is much smaller than the deionized water (6.49 dB) one. The optimal spacing of multiple C-TSV arrays filled with FC770 coolant is $600~mu text{m}$ (vertical transmission of 0.16 dB at 40 GHz). When the cooling cavity is embedded in the interposer with FC770 coolant, the maximum surface temperature of the power devices can be less than 56.8 °C at 250 W/cm2 heat flux. Compared with the solid silicon interposer, the maximum von Mises thermal stress of the C-TSV interposer with the embedded cooling cavity can be reduced by 44.8%.
      PubDate: Jan. 2022
      Issue No: Vol. 12, No. 1 (2022)
       
  • Experimental and Finite Element Analysis of Epoxy-Based Composites for
           Packaging Materials to Reduce Electric Field and Power Loss Under AC and
           DC Conditions

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      Authors: Qilong Wang;Xiangrong Chen;Chao Dai;Ashish Paramane;Muhammad Awais;Na Ren;
      Pages: 11 - 26
      Abstract: This work focuses on the performance of epoxy microcomposites, nanocomposites, and micro–nano hybrid composites as the packaging material of the power modules. The experiments consist of thermal conductivity, differential scanning calorimetry (DSC), space charge, dc electrical conductivity, thermally stimulated depolarization current (TSDC), and dielectric spectroscopy measurements. Moreover, the ac stationary electric field simulation and the dc transient electric field simulation are performed to analyze the electrical performance of the epoxy composites as the packaging materials in the power module structure under ac voltage and dc voltage, respectively. The ac field simulation uses dielectric spectroscopy data to obtain the electric field and power loss of the epoxy composites at different temperatures and frequencies under the ac voltage. On the other side, the dc electrical conductivity and TSDC experiment data are used for the dc transient electric field simulation to obtain the electric field considering the space charge under the dc voltage. The results show that the optimal addition of the filler content (20 wt% micro-AlN and 5 wt% nano-AlN) in the epoxy micro–nano hybrid composites can reduce the power loss and electric field at 150 °C and 1 MHz, under the ac condition. Furthermore, considering the space charge under the dc voltage, the electric field can also be reduced in epoxy micro–nano hybrid composites compared to pure epoxy.
      PubDate: Jan. 2022
      Issue No: Vol. 12, No. 1 (2022)
       
  • High-Density Electrical and Optical Assembly for Subminiature VCSEL-Based
           Optical Engine

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      Authors: Naohiro Kohmu;Maho Ishii;Takaaki Ishigure;
      Pages: 27 - 36
      Abstract: In this article, we propose a subminiature (10.9 mm $times56.6$ mm) vertical cavity surface-emitting laser (VCSEL)-based optical engine with a low crosstalk penalty for onboard applications. When applying optical engines to onboard interconnects, ICs [laser drivers and transimpedance amplifiers (TIAs)] and active optical devices (light sources and photodetectors) must be mounted densely to make the footprint as small as possible. It is a concern that such a high-density integration could increase the crosstalk between transmitter (Tx) and receiver (Rx) devices, which could be caused by the supply current difference between the circuit from laser drivers to light source and the circuit from photodetectors to TIAs. In this article, by inserting a gap in the ground electrode, a compact optical engine (less than half of the footprint of quad small form-factor pluggable-double density (QSFP-DD) compliant engines) enabling a 25.78-Gb/s error-free optical transmission is successfully fabricated. We optimize the gap width to decrease the crosstalk while maintaining efficient heat dissipation via the electrode. We compare the characteristics of the fabricated optical engine to the engine with the gap-less ground electrode structure formed in the same compact size. Then, we both theoretically and experimentally confirm a link power budget savings of about 1.8 dB, which is sustained even under high-temperature ( $T_{c} = 70,,^{circ }text{C}$ ) operation. In addition, to realize further high-density assembly, we also represent a lens-less optical coupling by inserting a 90o-bent graded-index (GI) core polymer waveguide between the optical transmitter and multimode fiber. The transmission performance of the 90o-bent GI-core waveguide is preliminarily evaluated, and we successfully transmit 53.125-Gb/s PAM4 opt-cal signals experimentally.
      PubDate: Jan. 2022
      Issue No: Vol. 12, No. 1 (2022)
       
  • Formation of High Density ⟨111⟩ Textured Nanotwins in Evaporated Ag
           Thin Films Through Post-Deposition Ion Bombardment

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      Authors: Pei-Ing Lee;Po-Ching Wu;Tung-Han Chuang;
      Pages: 37 - 41
      Abstract: For the production of Ag thin films containing a high density of nanotwins, evaporated Ag films were bombarded with an Ar+ ion beam with voltage of about 0.1 KeV. After the post-evaporation ion bombardment for 15 min, the equiaxial coarse grains in the surface region of the originally as-evaporated Ag films transformed into slender nanotwinned columns containing a highly $langle 111rangle $ textured nanotwinned structure with very thin twin spacing of about 8.6 nm. The nanotwinned columns increased with extension of the ion bombardment time to 30 min. The appearance of (111)-oriented fine grains in top-view electron backscatter diffraction (EBSD) images confirmed the high density of Ag nanotwins. Meanwhile, the roughness of the thin films increased after ion bombardment of the evaporated Ag films. Finally, a mechanism of nanotwin formation based on stress relaxation in evaporated Ag films through post-deposition ion bombardment is proposed.
      PubDate: Jan. 2022
      Issue No: Vol. 12, No. 1 (2022)
       
  • A Novel Approach to Evaluate and Predict the Impact of Randomly
           Distributed Voids on Junction Temperature for Power Modules

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      Authors: Yidian Shi;Wenhui Zhu;Hu He;
      Pages: 42 - 50
      Abstract: Solder joints play a significant role in modern electronic packaging; however, the presence of process-induced voids within a solder layer remains a crucial concern to the reliability and performance of interconnects. Porosity (i.e., void fraction of solder layer), void size, void location, and void distribution are key factors affecting the thermal characteristics of power modules. A quantitative description regarding the effects of these main factors on junction temperature is yet confirmed, especially for void distributional effect. In this work, a novel descriptor, $S$ value, was presented to analyze the effect of randomly distributed voids with nonuniform size on junction temperature. The proposed $S$ value was calculated to demonstrate the clustering effect of local voids on heat accumulation, and thus, the prediction of thermal hazard zone was achieved accordingly. It was found that a higher upper limit of voids radius would cause a comparable increase in junction temperature, which followed a similar trend of the effect of porosity. Furthermore, an expression consisting of porosity, maximum voids’ size, and maximum $S$ value was confirmed to predict the junction temperature and the corresponding location with less failure rate, which provided a statistical model to evaluate the thermal performance of solder layer.
      PubDate: Jan. 2022
      Issue No: Vol. 12, No. 1 (2022)
       
  • Research on Flip-Chip Bonding Process and Thermal Cycle Reliability
           Simulation of 3-D Stacked Structure

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      Authors: Mingming Chen;Yuexin Zhang;Yuhua Guo;Tianxiang Wu;Long Dou;Wenya Tian;Jinqing Xiao;Junhui Li;
      Pages: 51 - 58
      Abstract: In modern society, electronic equipment continues to develop in the direction of miniaturization and multifunction. In order to meet this requirement, packaging technology has gradually evolved from “2-D planar packaging” to “3-D packaging.” The realization of the flip-chip bonding process and the thermal cycle reliability of the 3-D stacked structure are discussed in this article. First, to stack three substrates and a small size chip together, the flip-chip bonding machine was used to vertically stack the chips in the $Z$ -direction. Then, the finite element software was used to analyze the thermal stress distribution of the overall structure under the thermal cycle load, and the life of the critical solder joints in the package was predicted. The simulation results show that, compared to the solder joints between the substrates, the copper pillar bumps of the small-size chip had a longer life.
      PubDate: Jan. 2022
      Issue No: Vol. 12, No. 1 (2022)
       
  • Statistical Analysis of the Thermal Performance and Reliability in the
           Heat Sink With Heat Pipes for the Power Electronics Module

    • Free pre-print version: Loading...

      Authors: C. W. Han;S. C. Sung;K. M. Choi;
      Pages: 59 - 68
      Abstract: Cooling devices are often used with power electronics systems to allow them to operate stably over long periods of time, they help guarantee not only thermal performance but also reliability. To understand the performance of these cooling devices it is important that they are verified by various types of testing, also the test results themselves should be quantified and analyzed using recognized statistical methods. For this article, we investigated an air-cooled heat sink with heat pipes (HPS) by conducting heat load, high/low temperature storage limits test, accelerated life test (ALT), and transport vibration test (TVT). The collected experimental data were analyzed by statistical methods, such as the independent samples $T$ -test, the paired samples $T$ -test, correlation analysis, process capability analysis, and the tolerance interval analysis. A newly manufactured power conditioning system had one heat sink on which the two power electronics modules were attached while providing a heat load of up to 3.2 kW. It was found that there was no deterioration in the thermal performance of the heat sink due to vibrations while being transported from the Republic of Korea to the United States. If such a heat sink is used for more than 20 years, it is anticipated that there will be a performance degradation of 6.2% over those years with a 95% confidence level for a B10 life. Based on our accelerated life testing, the heat sink is capable of dealing with a heat load of up to 3.1 kW over the design lifetime of 20 years. Thermal engineers should eventually introduce design margins in consideration of the reduction in quality and reliability that can occur over the lifetime of a cooling device.
      PubDate: Jan. 2022
      Issue No: Vol. 12, No. 1 (2022)
       
  • Numerical and Experimental Analyses of Component Failure Risk in a Mobile
           Phone Under Drop Test

    • Free pre-print version: Loading...

      Authors: Zhen Liu;Mingang Fang;Lei Shi;Zhuo Chen;Jianhui Li;Haohui Long;Wenhui Zhu;
      Pages: 69 - 79
      Abstract: Owing to the complex stress condition of the on-board devices in a mobile phone under drop impact condition, high test cost, and long validation period are usually spent on product-level drop test for product design. Most of the standardized test protocols including the Joint Electron Device Engineering Council (JEDEC) standard for handheld electronic products are essentially based on board-level tests, not taking into account the interaction between the printed circuit board (PCB) and other internal components, so the accurate experimental validation of product-level drop reliability remains time-consuming. This article established a finite element model of a whole mobile phone for the simulation of its product-level drop tests. By conducting simulation of six-side and four-corner drop postures, it is found that the risk of overstress failure of the critical large chips and solder joints on the PCB are relatively higher in the case of back drop and front drop. The bending of the PCB and the collision between the shielding frame and the front frame of the mobile phone are the decisive factors that bring the overstress failure risk of the chip and solder joint. Finally, a series of product-level drop tests were conducted and compared with the simulations, with a variance of stress value within 20%, which proves that the simulation model could provide useful insights for the reliability design and validation phase during the development of new products.
      PubDate: Jan. 2022
      Issue No: Vol. 12, No. 1 (2022)
       
  • Geometry Influence on Fracture Behavior of Lap-Shear Solder Joints

    • Free pre-print version: Loading...

      Authors: Mojtaba Karimi;Amir Nourani;Sobhan Honarvar;
      Pages: 80 - 88
      Abstract: Single lap-shear (SLS) specimens of 63Sn37Pb solder joints were prepared with three different adherend thicknesses at three varying joint lengths. The fracture force was measured at a shear strain rate of 0.01 s−1 for different geometries. The elastic–plastic fracture mechanics (EPFM) theory was used to find the energy dissipated in each case using a finite element model (FEM), and the fracture energy was obtained by cohesive zone modeling (CZM). Both 2-D and 3-D models were used to explain the variations in fracture energy by the level of constraint on the joint. Also, the plastic zone area and stress distribution along the solder layer were calculated at the moment of fracture. A phase angle definition was proposed and compared in different solder lengths to show its influence on fracture energy. It was concluded that the fracture energy was influenced by the local phase angle and plastic zone area at the moment of fracture. The effect of adherend thickness on fracture load was significant especially for long joints (i.e., lengths of 6.35 and 12.7 mm). The observations on the crack path showed that the crack was initiated near one of the adherends and tended to propagate within the intermetallic compound (IMC) layer. Also, the planar fracture surface was observed in all the specimens except for the short solder joints (i.e., with the length of 2.54 mm).
      PubDate: Jan. 2022
      Issue No: Vol. 12, No. 1 (2022)
       
  • DC IR-Drop Analysis of Power Distribution Networks by a Robin Transmission
           Condition-Enhanced Discontinuous Galerkin Method

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      Authors: An Fa Yang;Min Tang;Jun Fa Mao;Li Jun Jiang;Hakan Baǧcıi;Ping Li;
      Pages: 89 - 99
      Abstract: In this work, a novel Robin transmission condition (RTC)-enhanced discontinuous Galerkin (DG) method is proposed for the dc IR-drop analysis of power distribution networks with Joule heating effects included. Unlike the conventional DG method, the proposed DG method straightforwardly applied to discretize the second-order spatial partial differential governing equations for the electrostatic potential $Phi $ and the steady-state temperature $T$ . The numerical flux in DG used to facilitate the information exchange among neighboring subdomains introduces two additional variables: the current density $J$ for the electrical potential equation and the thermal flux $q$ for the thermal equation. To solve them, at the interface of neighboring subdomains, an RTC is presented as the second equation to establish another connection for solutions in neighboring subdomains. With this strategy, the number of degrees of freedom (DoFs) involved in the proposed RTC-DG method is dramatically reduced compared with the traditional DG method. The finalized matrix system is solved in an finite-element tearing and interconnecting (FETI)-like procedure, namely the unknowns are obtained in a subdomain-by-subdomain scheme. Finally, the accuracy and the efficiency of the proposed RTC-DG method are validated by several representative examples.
      PubDate: Jan. 2022
      Issue No: Vol. 12, No. 1 (2022)
       
  • Reinforcement-Learning-Based Signal Integrity Optimization and Analysis of
           a Scalable 3-D X-Point Array Structure

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      Authors: Kyungjune Son;Minsu Kim;Hyunwook Park;Daehwan Lho;Keeyoung Son;Keunwoo Kim;Seongsoo Lee;Seungtaek Jeong;Shinyoung Park;Seokwoo Hong;Gapyeol Park;Joungho Kim;
      Pages: 100 - 110
      Abstract: In this article, we, for the first time, propose a reinforcement learning (RL) model to design an optimal 3-D cross-point (X-Point) array structure considering signal integrity issues. The interconnection design problem is modeled to the Markov decision process (MDP). The proposed RL model designs the 3-D X-Point array structure based on three reward factors: the number of bits, the crosstalk, and the IR drop. We applied multilayer perceptron (MLP) and long short-term memory (LSTM) to parameterize the policy. Proximal policy optimization (PPO) is used to optimize the parameters to train the policy. The reward of the proposed RL model is well-converged with variations in the array structure size and hyperparameters of the reward factors. We verified the scalability and sensitivity of the proposed RL model. With the optimal 3-D X-Point array structure design, we analyzed the reward factor and signal integrity issues. The optimal design of the 3-D X-Point array structure shows 17%–26.5% better signal integrity performance than the conventional design in finer process technology. In addition, we suggest a range of possible directions for improvement of the proposed model with variations in MDP tuples, reward factors, and learning algorithms, among other factors. Using the proposed model, we can easily design an optimal 3-D X-Point array structure with a certain size, performance capabilities, and specifications based on reward factors and hyperparameters.
      PubDate: Jan. 2022
      Issue No: Vol. 12, No. 1 (2022)
       
  • Millimeter-Wave Active Integrated Semielliptic CPW Slot Antenna With
           Ultrawideband Compensation of Ball Grid Array Interconnection

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      Authors: Hao-Ran Zhu;Kun Li;Jia-Guo Lu;Jun-Fa Mao;
      Pages: 111 - 120
      Abstract: In this article, a millimeter-wave bidirectional active integrated coplanar waveguide slot antenna with ball grid array (BGA) interconnection is proposed. Symmetric multistage step impedance resonator matching network and tapered shaped structures are utilized to ultrawideband compensate the reactance behavior of the vertical BGA transition, which can be employed to reduce the interconnection length among different modules. By gradually changing the width of the semielliptic slot, an ultrawideband radiation behavior is achieved with a small impedance variation from one resonate mode to another. The proposed 1 $times $ 4 passive antenna array can operate from 25 to 40 GHz with a gain of 13.1 dB. Compared with the conventional active integrated antenna structures, good advantages of wide bandwidth and high gain are obtained with the proposed technique. The prototype of the presented active antenna array is fabricated and measured with a wide impedance bandwidth of 29.1–40 GHz and can be more suitable for high-solution radar sensor.
      PubDate: Jan. 2022
      Issue No: Vol. 12, No. 1 (2022)
       
  • Fast and Stable Circuit Simulation via Interpolation- Supported Numerical
           Inversion of the Laplace Transform

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      Authors: Emad Gad;Ye Tao;Michel Nakhla;
      Pages: 121 - 130
      Abstract: The modified numerical inversion of the Laplace transform (dubbed NILT) has been recently proposed as a fast and provably stable numerical simulation for general circuits. Although it has enabled increasing the simulation time step, it highlighted the need for robust approach that can recover the full waveform in between the time points generated by NILT. This article presents a new approach that addresses this challenge. The proposed approach leverages the NILT framework from a high-order approximation paradigm that computes points on the circuit waveforms to a methodology that computes high-order derivatives of the waveforms at the same points. Using those derivatives, an interpolation approach based on Hermite interpolation is used to construct the circuit waveforms on dense points. Numerical experiments are presented to demonstrate the accuracy of both approaches.
      PubDate: Jan. 2022
      Issue No: Vol. 12, No. 1 (2022)
       
  • Multiphysics Challenges and Opportunities for Integrated Voltage
           Regulators in Power Delivery Architectures

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      Authors: Venkatesh Avula;Bidyut Bhattacharyya;Vanessa Smet;Yogendra Joshi;Madhavan Swaminathan;
      Pages: 131 - 146
      Abstract: Integrated voltage regulator (IVR)-based power delivery architectures have become a growing trend in high-performance computing (HPC) systems. Integrated power delivery architectures typically feature high-frequency switching devices and embedded passive components, which can be integrated either inside the die or in the package. However, dense functional integration in such architectures though necessary brings a new set of challenges to system designers. In this article, we study the impact of heterogeneous integration on the design of power delivery architectures that addresses issues related to electrical, thermal, and electromagnetic domains through test cases. The key design problems arising out of heterogeneous integration and the solutions for each of the domains are identified. Although the electrical impedance profile seen by the load becomes flatter in the frequency domain with fewer resonances, noise coupling at the load increases due to the close proximity of noise sources. The electromagnetic interference (EMI) levels are higher, and therefore, more EMI and noise mitigating filters are needed for judicious placement at the package and die level. High thermal resistance associated with embedded passives results in a threshold for power losses in embedded inductors beyond which the conventional top-level cooling is insufficient and a local cooling solution is needed.
      PubDate: Jan. 2022
      Issue No: Vol. 12, No. 1 (2022)
       
  • A TSV-Based 3-D Electromagnetic Bandgap Structure on an Interposer for
           Noise Suppression

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      Authors: Changle Zhi;Gang Dong;Zhangming Zhu;Yintang Yang;
      Pages: 147 - 154
      Abstract: For efficient and broadband noise suppression in grid-type power distribution networks (PDNs), a novel TSV-based 3-D electromagnetic bandgap (EBG) structure with an accurate and fast circuit model for predesign is proposed for the first time. The proposed structure is suitable for a silicon interposer-based system-in-package (SIP) for small size, high-density RF applications with the development of various portable terminals or other small devices. It is divided into a 3-D capacitor and a 3-D inductor, which are composed of TSVs and redistribution layers (RDLs). Profiting from the high-density integration of TSV devices, the proposed EBG can overcome the shortcomings of the existing structures, such as narrow bandgaps, large areas, and incompatibility with grid-type PDNs. The new structure effectively suppresses the simultaneous switching noise (SSN) in the interposer generated by chips or other modules. The EBG structure produces a noise suppression bandwidth (below −40 dB) of 13.22 GHz, ranging from 6.69 to 19.91 GHz with a fractional bandwidth (FBW) of 166.9%. Moreover, based on the equivalent circuit model, the bandgap of the proposed EBG can be adjusted by changing the structure parameters for diverse noise scenarios. Subsequently, to further reduce the device size, the EBG isolation wall is designed, and high performance is observed.
      PubDate: Jan. 2022
      Issue No: Vol. 12, No. 1 (2022)
       
  • Investigation Into Chemistry and Performance of No-Clean Flux in Fine
           Pitch Flip-Chip Package

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      Authors: Saif Wakeel;A. S. M. A. Haseeb;M. A. Amalina;Khoo Ly Hoon;
      Pages: 155 - 167
      Abstract: This study investigates the chemistry and performance of two commercial no-clean fluxes (NCFs) ii.e., NC-1 and NC-2. One water-soluble (WS) flux was also studied for comparison. Chemistry of these fluxes and their residues was studied using the Fourier transmission infrared (FTIR) spectroscopy. Thermal behavior of the flux was evaluated using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Hygroscopicity of the residue was determined using water contact angle on residue-contaminated substrates. These fluxes were used to prepare fine pitch ( $150~mu text{m}$ ) flip-chip package ( $17times17$ mm2) containing solder bump and copper pillar. Performance of each flux was evaluated using wettability of preprinted SAC-305 solder on copper substrate. Die pull strength of solder bump was evaluated and failure mode was analyzed using scanning electron microscopy (SEM). FTIR results showed that carboxylic acids, tertiary amine, and ether were present in NC-1. Carboxylic acid, secondary amide, and ether were observed in NC-2. WS showed the presence of carboxylic acid, secondary amine, ether, and alcohol. Residue showed the presence of carboxylic acid and amine in NC-1 and only amide in NC-2. Evaporation of certain monocarboxylic acids and ether solvent in NCF led to minimal residue compared to WS. Residue of WS was highly hygroscopic compared to N CF. Wetting of solder bump prepared by using NC-1 and NC-2 was better than WS, which is related to flux chemistry. Consequently, higher die pull strength was observed for N CF.
      PubDate: Jan. 2022
      Issue No: Vol. 12, No. 1 (2022)
       
  • Additive Manufacture of Custom Radiofrequency Connectors

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      Authors: Kyle Mcparland;Zachary Larimore;Paul Parsons;Austin Good;John Suarez;Mark Mirotznik;
      Pages: 168 - 173
      Abstract: We present the design and characterization of fully additively manufactured (AM) SubMiniature version A (SMA) connectors for use up to 18 GHz. Three-dimensional printed connectors can be directly integrated into the radio-frequency (RF) circuit without post-process bonding and can be fabricated into unusual shapes. The flexibility this affords in the manufacturing process offers significant advantages, especially for applications that need to meet strict size and volume constraints. To that end, we describe modifications to the traditional SMA design that better enable AM fabrication. A variety of different connector geometries were printed and fully characterized both electromagnetically and mechanically. Experimental measurements up to 18 GHz demonstrated good RF performance with low insertion losses (< 0.5 dB). Mechanical testing showed that the printed connectors could withstand up to 4.5 kg of direct force for extended periods of time without damage to the printed threads or other connector parts. Additionally, the printed connectors demonstrated good RF performance after repeated use.
      PubDate: Jan. 2022
      Issue No: Vol. 12, No. 1 (2022)
       
  • Epoxy Molding Compound Filler Clogging Simulation During Integrated
           Circuit Encapsulation Process

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      Authors: Bo-Heng Chen;Sheng-Jye Hwang;Yu-Yang Chang;Yu-Shuo Yang;Huei-Huang Lee;Bing-Yuan Huang;Ian Hu;Dao-Long Chen;David Tarng;C. P. Hung;
      Pages: 174 - 184
      Abstract: As IC components become denser and smaller in a package, more problems emerge. In the mold filling process, because epoxy molding compound (EMC) contains approximately 80 wt.% silica fillers, the fillers may clog at the gate of gap if the gap height between the component and the substrate is too small. This clogging will cause a popcorn effect due to the high resin content in the gap. In order to determine the EMC filling process in the mold cavity and the relation between the gap height and the filler size, we simulate the EMC filling process and the EMC filler concentration distribution in the mold cavity using mold flow analysis software and then use computational fluid dynamics-discrete element method (CFD-DEM) coupling method to simulate the EMC filler motion to determine the relationship between gap height and filler size and the factors that affect filler clogging. Based on the mold flow analysis results, the filler concentration was higher at the gate of gap than in other regions, and the filler concentration at the gate of gap for the 30- $mu text{m}$ gap-height model was higher than that for the 50- $mu text{m}$ gap-height model. Based on the DEM-CFD coupling results, particles with a single diameter larger than one-half of the gap height caused particle clogging the gate of gap, and particles with a mean particle size larger than one-third of the gap height caused particle clogging the gate of gap.
      PubDate: Jan. 2022
      Issue No: Vol. 12, No. 1 (2022)
       
  • Applying Taguchi Method to Optimize Vacuum Printing Encapsulation Process

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      Authors: Chien-Yi Huang;Li-Cheng Shen;C. J. Chan;Chao-Hsuan Wang;
      Pages: 185 - 191
      Abstract: Under the prosperity of the global electronics industry, the current market requires consumer products, such as smartphones, notebook computers, tablet computers, and other portable electronic products, to become lighter, thinner, shorter, and smaller. The miniaturized design of the system-in-package (SiP) technology integrates multiple different chips, such as an array package [ball grid array/chip-scale package (BGA/CSP)] or a peripheral package [quad flat package/thin small outline package (QFP/TSOP)], as well as passive components, such as resistors and capacitors, into a single package module. The vacuum printing encapsulation system (VPES) features cost-efficiency and flexibility advantages, compared with traditional transfer molding and compression molding, and thus improves product reliability. However, as VPES is an emerging process, the impact of relevant VPES parameters has not yet been determined. Moreover, it has been discovered that there are still air bubbles in the cured epoxy molding compound (EMC). In this study, the Taguchi experimental design is applied to propose the optimal process parameter combination, including the squeegee moving speed: 20 mm/s, the printing delay time: 20 s, the number of squeegee printings: three, and the inner chamber vacuum: 3 kPa. The results of variance analysis show that the contributions of the number of squeegee printings and the inner chamber vacuum to the air bubble rate of the EMC adhesive material are 76.38% and 17.75%, respectively, which indicates that they have a significant impact. The results of confirmation testing show that the above optimal VPES process parameters can minimize the air bubble rate occurring in the EMC adhesive material and avoid the risks of short circuits in the tin bridge during the reflow process of the SiP module.
      PubDate: Jan. 2022
      Issue No: Vol. 12, No. 1 (2022)
       
  • Broadband Millimeter-Wave Dielectric Properties of Liquid Crystal Polymer
           Materials

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      Authors: Michael P. Mcgarry;Mahadevan K. Iyer;Mark Lee;
      Pages: 192 - 194
      Abstract: Liquid crystal polymers (LCPs) are a class of thermoplastic polymers widely used for packaging radio frequency (RF), microwave, and low millimeter (mm)-wave integrated circuits operating at frequencies as high as 77 GHz. Because of their relatively low cost and attractive electrical, thermal, and mechanical properties, LCPs are of potential interest as a packaging material for advanced circuits operating at high mm-wave frequencies, ~100–300 GHz. To potentially use LCPs at these frequencies will require a quantitative knowledge of the materials’ dielectric properties across a broad frequency band. Here, we present nondestructive measurements of the dielectric constant, Dk, and dissipation factor, Df, on six commercially made LCP materials now used for packaging RF/microwave circuits. Measurements using phase-sensitive transmission from 140 to 220 GHz show values of Dk ranging between 2.0 and 4.5, with four materials essentially nondispersive but two showing significant dispersion in this band. Df values were in the range 0.01–0.06, substantially higher than that has been reported for many LCP materials at RF/microwave frequencies. The results are useful to model accurately the performance of packaged mm-wave circuits.
      PubDate: Jan. 2022
      Issue No: Vol. 12, No. 1 (2022)
       
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      Pages: 195 - 196
      Abstract: This page or pages intentionally left blank.
      PubDate: Jan. 2022
      Issue No: Vol. 12, No. 1 (2022)
       
 
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