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Charles R. Sullivan - One of the best experts on this subject based on the ideXlab platform.

  • microfabricated racetrack Inductors with thin film magnetic cores for on chip Power conversion
    IEEE Journal of Emerging and Selected Topics in Power Electronics, 2018
    Co-Authors: Daniel V. Harburg, Alex J. Hanson, Christopher G. Levey, David M. Otten, Bradley A Reese, Jizheng Qiu, John Ranson, Charles R. Sullivan
    Abstract:

    This paper presents design methods and electrical performance measurements for microfabricated racetrack Power Inductors. Magnetic components with sputtered Co–Zr–O thin-film magnetic cores are demonstrated in a multimegahertz dc–dc converter for solid-state lighting applications. The high-Power-density and high-efficiency dc–dc converter is designed to transfer 25 W of Power at switching frequencies between 1 and 30 MHz. Utilizing our magnetic components, the converter achieves a 90% conversion efficiency at 4 MHz with an inductor Power density of 1 W/mm2 of substrate area. Small-signal measurements of the Inductors are compared with modeled predictions to validate the design optimization approach. Fabricated components achieved inductance values of 1.2 $\mu \text{H}$ and peak quality factors of 15.1 at 8.3 MHz.

  • on size and magnetics why small efficient Power Inductors are rare
    2016 International Symposium on 3D Power Electronics Integration and Manufacturing (3D-PEIM), 2016
    Co-Authors: Charles R. Sullivan, Bradley A Reese, Aaron L F Stein, Phyo Aung Kyaw
    Abstract:

    Of the three main component types needed in Power converters—switches, capacitors and Inductors—the most difficult to integrate on a semiconductor chip or in a planar package is the Inductors. This difficulty arises partly from process compatibility challenges with magnetic materials, and is exacerbated by the fact that, because most types of electronics don't need Inductors, there has been relatively little development effort. But a more fundamental challenge is the way magnetics performance scales with size. Capacitors and semiconductor devices can be made from thousands of small cells connected in parallel, but that approach would severely undercut the performance of magnetic components. Scaling relationships for magnetics are explored to demonstrate the inherent difficulty of small size and low profile magnetics. Cases considered include those with winding designs limited by skin and proximity effect and those constrained by efficiency and thermal dissipation. Small-scale magnetic components are typically limited by efficiency rather than heat dissipation. With efficiency constrained, and considering high frequency winding loss effects, it is shown that Power density typically scales as the linear dimension scaling factor to the fifth Power.

  • Measured performance and micro-fabrication of racetrack Power Inductors
    2013 IEEE Energy Conversion Congress and Exposition, 2013
    Co-Authors: Daniel V. Harburg, Alex J. Hanson, Yue Song, Rui Tian, Christopher G. Levey, Charles R. Sullivan, David M. Otten
    Abstract:

    This paper presents micro-fabrication results and electrical performance measurements for chip-scale racetrack Power Inductors. Magnetic components with sputtered Co-Zr-O magnetic cores are demonstrated in a multi-megahertz dc-dc converter for solid-state lighting applications. The dc-dc converter achieves an 89% conversion efficiency at 5 MHz with an inductor Power density of 1 W/mm2 of substrate area. Small-signal measurements of the Inductors are compared with modeled predictions to validate the design optimization approach. Fabricated components achieved inductance values of 1.2 μH and peak quality factors of 15.1 at 8.3 MHz.

  • microfabricated v groove Power Inductors using multilayer co zr o thin films for very high frequency dc dc converters
    IEEE Transactions on Power Electronics, 2013
    Co-Authors: Di Yao, Rui Tian, Christopher G. Levey, Charles R. Sullivan
    Abstract:

    V-groove microInductors are designed, fabricated, and tested for operation above 10 MHz. Multilayer nanogranular Co-Zr-O/ZrO2 magnetic thin films are used as the core material of these Inductors, to improve the magnetic performance of the films deposited on the sidewalls of V-grooves and to control eddy-current loss in the core. Prototype V-groove Inductors are fabricated in a Si substrate based on optimization results for 7 to 3.3-V, 1-A dc-dc buck converters. The Inductors exhibit an inductance of 3.4 nH from 10 to 100 MHz, a dc resistance of 3.83 mΩ, and a quality factor of up to at least 50. The prototype Inductors are a promising candidate for high-Power-density high-efficiency dc-dc converters. The measured inductor performance indicates that they could be used to make a 7 to 3.3-V, 1-A converter exhibiting a Power density of 2.5 W/mm2 and an efficiency of 86% at 100 MHz; or a Power density of 0.36 W/mm2 and an efficiency of 91% at 11 MHz.

  • On-chip RF Power Inductors with nanogranular magnetic cores using prism-assisted UV-LED lithography
    2013 Transducers & Eurosensors XXVII: The 17th International Conference on Solid-State Sensors Actuators and Microsystems (TRANSDUCERS & EUROSENSORS X, 2013
    Co-Authors: Daniel V. Harburg, Christopher G. Levey, Rezwan G. Khan, Florian Herrault, Jungkwun Kim, Charles R. Sullivan
    Abstract:

    This paper presents a CMOS-compatible microfabrication process for on-silicon racetrack Power Inductors using prism-assisted lithography with an ultraviolet light-emitting diode (UV-LED) array as a light source. This combination of lithographic techniques was applied in making 60-μm-tall SU-8 structures with 45° sidewalls to achieve high performance from a sputtered nanogranular magnetic core material, Co-Zr-O. Microfabricated magnetic components with Co-Zr-O cores were designed, built, and tested for use in a 25-W dc-dc Power converter operating at a switching frequency between 5-30 MHz. Fabricated Inductors achieved a peak quality factor of 18 and an inductance of 660 nH at 15 MHz.

Jizheng Qiu - One of the best experts on this subject based on the ideXlab platform.

  • microfabricated racetrack Inductors with thin film magnetic cores for on chip Power conversion
    IEEE Journal of Emerging and Selected Topics in Power Electronics, 2018
    Co-Authors: Daniel V. Harburg, Alex J. Hanson, Christopher G. Levey, David M. Otten, Bradley A Reese, Jizheng Qiu, John Ranson, Charles R. Sullivan
    Abstract:

    This paper presents design methods and electrical performance measurements for microfabricated racetrack Power Inductors. Magnetic components with sputtered Co–Zr–O thin-film magnetic cores are demonstrated in a multimegahertz dc–dc converter for solid-state lighting applications. The high-Power-density and high-efficiency dc–dc converter is designed to transfer 25 W of Power at switching frequencies between 1 and 30 MHz. Utilizing our magnetic components, the converter achieves a 90% conversion efficiency at 4 MHz with an inductor Power density of 1 W/mm2 of substrate area. Small-signal measurements of the Inductors are compared with modeled predictions to validate the design optimization approach. Fabricated components achieved inductance values of 1.2 $\mu \text{H}$ and peak quality factors of 15.1 at 8.3 MHz.

  • A toroidal Power inductor using radial-anisotropy thin-film magnetic material based on a hybrid fabrication process
    2013 Twenty-Eighth Annual IEEE Applied Power Electronics Conference and Exposition (APEC), 2013
    Co-Authors: Jizheng Qiu, Daniel V. Harburg, Charles R. Sullivan
    Abstract:

    This paper presents improvements for the design and fabrication of high-frequency toroidal Power Inductors with and without radial-anisotropy thin-film magnetic material. An improved winding resistance model for toroids is developed considering an angle factor for actual winding shape, the effect of spacing between turns and loss associated with exterior current in the circumferential direction. A hybrid process for fabricating low-profile magnetic-core toroids is presented. The process uses standard flex printed circuit board (PCB) technology for the top and bottom winding layers with vias electroplated after sandwiching the magnetic core between the two winding layers. Thin-film magnetic material (Co-Zr-O) is deposited in the presence of a radial magnetic field, which induces radial anisotropy in the toroidal core. Small-signal measurements show that the toroidal core has a relative permeability over 40 at frequencies up to several hundred megahertz, and very high quality factor in the frequency range below 100 MHz. Air-core and magnetic-core toroidal Inductors using this hybrid fabrication process were built and tested at small-signal levels. Magnetic-core toroids showed a higher inductance and quality factor than air-core toroids at frequencies below 100 MHz. This winding loss model and fabrication process can be applied to both air-core and magnetic-core toroidal Inductors.

  • design and fabrication of vhf tapped Power Inductors using nanogranular magnetic films
    IEEE Transactions on Power Electronics, 2012
    Co-Authors: Jizheng Qiu, Charles R. Sullivan
    Abstract:

    The design and fabrication of coupled Inductors with low profile, low cost, and high Power density for tapped-inductor high-step-down dc-dc Power converters in the very-high-frequency (30-300 MHz) range are presented. The inductor consists of a multilayer thin-polyimide printed circuit board with nanogranular thin-film magnetic material deposited on both sides and on beveled cuts to form a fully linked closed core. The magnetic material Co-Zr-O has good soft magnetic properties, high resistivity, and high flux density capability. Multilayer Co-Zr-O/ZrO2 thin films are used to improve the performance of the magnetic core. A winding loss model of this coupled inductor is presented. Coupled Inductors with turns ratios 2 and 10 for several different converter applications have been designed, fabricated, and measured. Loss in the magnetic material is investigated. Small-signal and large-signal measurements show good performance of the fabricated components with high-frequency, high-field excitation.

Etsuo Otsuki - One of the best experts on this subject based on the ideXlab platform.

  • Power loss analysis of SMD Power Inductors
    Conference Proceedings - IEEE Applied Power Electronics Conference and Exposition - APEC, 2011
    Co-Authors: Shinya Nakano, Tomoyuki Nakazawa, Yuji Matsumoto, Etsuo Otsuki
    Abstract:

    The Power loss analysis of SMD Power Inductors is one of essential subjects in the development of SMD Power Inductors and their application into switching Power supply circuits. However such developments have been done without Power loss analysis due to its difficulties, which should be attributed to the problems such as calculation of effective core parameters and consideration of leakage flux, coupling factor between wire and core etc. as well as measurement itself. This study is aimed to establish the loss measuring method for SMD Power Inductors. Especially the considerations was done in the determination of measuring condition, the effect of factors in measured results, subtraction of core loss from total Power loss etc. And we investigated the effect of DC-bias to the core loss.

Christopher G. Levey - One of the best experts on this subject based on the ideXlab platform.

  • microfabricated racetrack Inductors with thin film magnetic cores for on chip Power conversion
    IEEE Journal of Emerging and Selected Topics in Power Electronics, 2018
    Co-Authors: Daniel V. Harburg, Alex J. Hanson, Christopher G. Levey, David M. Otten, Bradley A Reese, Jizheng Qiu, John Ranson, Charles R. Sullivan
    Abstract:

    This paper presents design methods and electrical performance measurements for microfabricated racetrack Power Inductors. Magnetic components with sputtered Co–Zr–O thin-film magnetic cores are demonstrated in a multimegahertz dc–dc converter for solid-state lighting applications. The high-Power-density and high-efficiency dc–dc converter is designed to transfer 25 W of Power at switching frequencies between 1 and 30 MHz. Utilizing our magnetic components, the converter achieves a 90% conversion efficiency at 4 MHz with an inductor Power density of 1 W/mm2 of substrate area. Small-signal measurements of the Inductors are compared with modeled predictions to validate the design optimization approach. Fabricated components achieved inductance values of 1.2 $\mu \text{H}$ and peak quality factors of 15.1 at 8.3 MHz.

  • Measured performance and micro-fabrication of racetrack Power Inductors
    2013 IEEE Energy Conversion Congress and Exposition, 2013
    Co-Authors: Daniel V. Harburg, Alex J. Hanson, Yue Song, Rui Tian, Christopher G. Levey, Charles R. Sullivan, David M. Otten
    Abstract:

    This paper presents micro-fabrication results and electrical performance measurements for chip-scale racetrack Power Inductors. Magnetic components with sputtered Co-Zr-O magnetic cores are demonstrated in a multi-megahertz dc-dc converter for solid-state lighting applications. The dc-dc converter achieves an 89% conversion efficiency at 5 MHz with an inductor Power density of 1 W/mm2 of substrate area. Small-signal measurements of the Inductors are compared with modeled predictions to validate the design optimization approach. Fabricated components achieved inductance values of 1.2 μH and peak quality factors of 15.1 at 8.3 MHz.

  • microfabricated v groove Power Inductors using multilayer co zr o thin films for very high frequency dc dc converters
    IEEE Transactions on Power Electronics, 2013
    Co-Authors: Di Yao, Rui Tian, Christopher G. Levey, Charles R. Sullivan
    Abstract:

    V-groove microInductors are designed, fabricated, and tested for operation above 10 MHz. Multilayer nanogranular Co-Zr-O/ZrO2 magnetic thin films are used as the core material of these Inductors, to improve the magnetic performance of the films deposited on the sidewalls of V-grooves and to control eddy-current loss in the core. Prototype V-groove Inductors are fabricated in a Si substrate based on optimization results for 7 to 3.3-V, 1-A dc-dc buck converters. The Inductors exhibit an inductance of 3.4 nH from 10 to 100 MHz, a dc resistance of 3.83 mΩ, and a quality factor of up to at least 50. The prototype Inductors are a promising candidate for high-Power-density high-efficiency dc-dc converters. The measured inductor performance indicates that they could be used to make a 7 to 3.3-V, 1-A converter exhibiting a Power density of 2.5 W/mm2 and an efficiency of 86% at 100 MHz; or a Power density of 0.36 W/mm2 and an efficiency of 91% at 11 MHz.

  • On-chip RF Power Inductors with nanogranular magnetic cores using prism-assisted UV-LED lithography
    2013 Transducers & Eurosensors XXVII: The 17th International Conference on Solid-State Sensors Actuators and Microsystems (TRANSDUCERS & EUROSENSORS X, 2013
    Co-Authors: Daniel V. Harburg, Christopher G. Levey, Rezwan G. Khan, Florian Herrault, Jungkwun Kim, Charles R. Sullivan
    Abstract:

    This paper presents a CMOS-compatible microfabrication process for on-silicon racetrack Power Inductors using prism-assisted lithography with an ultraviolet light-emitting diode (UV-LED) array as a light source. This combination of lithographic techniques was applied in making 60-μm-tall SU-8 structures with 45° sidewalls to achieve high performance from a sputtered nanogranular magnetic core material, Co-Zr-O. Microfabricated magnetic components with Co-Zr-O cores were designed, built, and tested for use in a 25-W dc-dc Power converter operating at a switching frequency between 5-30 MHz. Fabricated Inductors achieved a peak quality factor of 18 and an inductance of 660 nH at 15 MHz.

  • microfabricated v groove Power Inductors using multilayer co zr o thin films for very high frequency dc dc converters
    Energy Conversion Congress and Exposition, 2011
    Co-Authors: Di Yao, Christopher G. Levey, Charles R. Sullivan
    Abstract:

    Microfabricated V-groove Inductors targeted to operate above 10 MHz are fabricated and tested. Multilayer nano-granular Co-Zr-O/ZrO 2 magnetic thin films are used as the core material of the Inductors to improve the magnetic performance of the films deposited on the sidewalls of V-grooves and to control eddy-current loss in the core. Prototype V-groove Inductors are fabricated based on optimization results for 7-V to 3.3-V, 1-A dc-dc buck converters. The Inductors exhibit inductance of 3.4 nH from 10 MHz to 100 MHz, dc resistance of 3.83 mΩ, and quality factor up to 66. The prototype Inductors are a promising candidate for high-Power-density high-efficiency dc-dc converters. The measured inductor performance indicates that they could be used to make a 7-V to 3.3-V, 1-A converter that would exhibit Power density of 2.5 W/mm2 and efficiency of 86% at 100 MHz; or Power density of 0.36 W/mm2 and efficiency of 91% at 11 MHz.

Rao Tummala - One of the best experts on this subject based on the ideXlab platform.

  • Inductors: Micro- to Nanoscale Embedded Thin Power Inductors
    Nanopackaging, 2018
    Co-Authors: P. Markondeya Raj, Gopal C. Jha, Sun Teng, Himani Sharma, Swapan K. Bhattacharya, Rao Tummala
    Abstract:

    Inductors are critical storage components in Power converters. Their large size is, however, a major bottleneck for Power module integration and efficient Power management. High-density Inductors can migrate the Power converter close to the load. This can lead to lower losses and more efficient and granular Power delivery. However, traditional magnetic materials cannot achieve high Power density and current handling. Nanomagnetic films provide unique opportunities to enhance permeability, reduce core losses, and integrate Inductors close to the chip. Introduction of magnetic anisotropy into the films provides an additional degree of freedom to further enhance current handling. This chapter reviews the fundamentals of nanomagnetic materials and designs for inductor cores with various topologies and illustrates their superiority over traditional materials. Such films can also be applied to RF components for improved inductance density.

  • magnetic materials and design trade offs for high inductance density high q and low cost Power and emi filter Inductors
    Electronic Components and Technology Conference, 2016
    Co-Authors: Teng Sun, Himani Sharma, Markondeya P Raj, Junki Min, Tadashi Takahashi, Keiji Takemura, Hobie Yun, Francesco Carobolante, Rao Tummala
    Abstract:

    This paper investigates the trade-offs in inductance density and quality factor of Inductors with and without magnetic-cores through modeling, design, fabrication and model validation through characterization. Two type of Inductors, one for Power-supply and the other for EMI filters, are investigated. Parametric analysis was performed to study the enhancement in inductance density without compromising the current handling and efficiency. For EMI filter Inductors, the inductance and quality factor (Q) were improved by 13X and 4X respectively with and without magnetic cores. For Power Inductors, the inductance and quality factor were improved by 5X and 1.6X respectively. The fabricated magnetic core Inductors achieved 5X reduction in thickness, compared to the stage-of-the art air-core Inductors which use multilayered and thick solenoid.

  • design fabrication and characterization of thin Power Inductors with multilayered ferromagnetic polymer composite structures
    Microelectronic Engineering, 2016
    Co-Authors: Dibyajat Mishra, Markondeya P Raj, Rao Tummala
    Abstract:

    This paper presents the design, fabrication and characterization of ultra-thin Inductors using a new class of multilayered ferromagnetic-polymer composite structures as magnetic cores. The multilayered composite structures comprise of high-permeability, high saturation magnetization (Ms0.5T), low-coercivity magnetic layers stacked with ultrathin polymer adhesives. The adhesive acts as an insulating layer to reduce eddy current losses while also preventing degradation in permeabilities at higher operating frequencies. Toroid-based integrated Inductors were designed with the composite structures to operate in the low MHz range for Power conversion applications. The magnetic composite film synthesis and patterning was successfully combined with toroid coils in order to fabricate the Inductors. The process of micro-patterning the composite structure and forming 3D coils around them to demonstrate ultra-thin Inductors is described in detail. The fabricated Inductors with the multilayered magnetic composite films showed stable inductance beyond 10MHz and 10× enhancement in inductance density over air-core Inductors with the same designs.

  • Multilayered Ferromagnetic Polymer Composite Structures for High-Density Power Inductors
    IEEE Transactions on Magnetics, 2016
    Co-Authors: Dibyajat Mishra, P. Markondeya Raj, Joel Tishler, Teng Sun, Erik Shipton, Rao Tummala
    Abstract:

    This paper presents the modeling, design, processing, and characterization of a new class of multilayered ferromagnetic polymer composite structures for high-density Power inductor applications. The multilayered composite structures comprise high-permeability, high saturation magnetization ( $M_{s} > 0.5$ T), and low-coercivity magnetic layers stacked with ultra-thin polymer adhesives. The adhesive acts as an an insulating layer to reduce eddy current losses while also enabling high permeabilities at higher operating frequencies. Fundamental material models were used to design the composite structures to achieve a permeability of above 500 in the frequency range of 1–10 MHz. A new adhesive coating and layering process was developed to achieve thicker composite structures in a single lamination step for increasing the inductance density and Power handling. The frequency-dependent effective permeability of the composite structure was estimated from the measurement and analysis of $S_{11}$ parameters from a shorted strip transmission line using a vector network analyzer. The fabricated composite structures showed a permeability of $\sim 500$ , saturation magnetization of 0.6 T, and a coercivity of 4.4 Oe at 10 MHz. Such composite structures with excellent magnetic properties can be used to design Power Inductors in the 1–10-MHz frequency range.

  • ultra thin and ultra small 3d double side glass Power modules with advanced Inductors and capacitors
    Electronic Components and Technology Conference, 2015
    Co-Authors: Saumya Gandhi, Srikrishna Sitaraman, Himani Sharma, Markondeya P Raj, Bruce Chou, Parthasarathi Chakraborti, Min Suk Kim, Venky Sundaram, Rao Tummala
    Abstract:

    This paper demonstrates 3D functional modules that are ultra-miniaturized, high-performance and low-cost, based on an innovative 3D Integrated Passive and Active Component (3D IPAC) concept [1]. The 3D IPAC concept utilizes an ultra-thin (30–100 microns) and ultra-low-loss glass substrate, low-cost through-package-vias (TPVs) and double-side redistribution layers (RDL) for assembly of both active and passive components. In this concept, both active and passive components are integrated on both sides of the glass substrate, either as thinfilms or as discretely fabricated and assembled components, separated by only about 50–100 microns in interconnection length. This paper specifically addresses the Power functional modules with passive components by integrating ultra-thin high-density capacitors on one side and Power-supply Inductors on the other side. The first part of the paper describes the electrical modeling and design of Power Inductors and capacitors in 3D IPAC structure. The second section describes the fabrication for both the building block L and C components and the assembly of integrated modules. The last section presents the electrical characterization. The paper, thus, provides a first demonstration of a novel Power module platform for double-side thin active and passive component integration for Power module applications.