GE Vingmed Ultrasound AS

Horten, Norway

GE Vingmed Ultrasound AS

Horten, Norway

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Eggen T.,GE Vingmed Ultrasound AS
2016 6th Electronic System-Integration Technology Conference, ESTC 2016 | Year: 2016

Au-Sn Solid-Liquid Interdiffusion (SLID) bonding of a standard piezoelectric material (PZT) to tungsten carbide (WC) has been investigated. Both materials have a bare bonding surface with an absolute roughness up to 1.5 μm. Bonded samples were characterized by means of acoustic coupling between the PZT and the WC, through electrical impedance measurements. Furthermore, the electrical impedance measurements were employed as a novel method for non-destructive characterization of voids in bond-lines. The results from the non-destructive impedance measurements were compared with the traditional cross-sectional microscopy to inspect voids in SLID bonds, showing good correspondence. Successful Au-Sn SLID bonding of a PZT to a WC is achieved at a temperature higher than 300 °C and a heating rate as high as 120 °C/minute. The bond-line consists of a layered structure Au/Au-Sn (ζ phase)/Au, in accordance with previous studies. Prior to the cross-sectional microscopy, the difference in the bond-lines is clearly observed by the non-destructive electrical impedance measurements. The present study has demonstrated the feasibility of adopting Au-Sn SLID bonding to samples with a high surface roughness. © 2016 IEEE.


Nguyen H.-V.,Buskerud and Vestfold University College | Kristiansen H.,Conpart AS | Johannessen R.,GE Vingmed Ultrasound AS | Andreassen E.,Buskerud and Vestfold University College | And 4 more authors.
Proceedings - Electronic Components and Technology Conference | Year: 2011

An isotropic conductive adhesive (ICA) filled with metalcoated polymer spheres (MPS) has been studied as a novel approach to increase the flexibility, and hence the reliability, compared to the conventional metal-filled ICA. In this study, the effect of the metal coating on the die shear strength was investigated by comparing ICA materials with coated and uncoated polymer spheres. The other important part of the study was to assess the temperature dependence of the die shear strength of an MPS-based ICA, and also compare this with the behavior of a conventional ICA filled with Ag particles. The results showed that the metal coating does not have a critical effect on the die shear strength of ICA filled with MPS. The die shear strengths obtained for the MPSbased ICA and the conventional Ag-filled ICA have the same temperature dependence in the range of 20 °C to 120 °C. Furthermore, none of the ICA systems has experienced a critical drop in die shear strength at and above the glass transition temperature. © 2011 IEEE.


Nguyen H.-V.,Buskerud and Vestfold University College | Andreassen E.,Buskerud and Vestfold University College | Andreassen E.,Sintef | Kristiansen H.,Conpart AS | And 3 more authors.
Materials and Design | Year: 2013

Novel isotropic conductive adhesives (ICAs) filled with metal-coated polymer spheres have been introduced in order to improve the mechanical reliability compared to conventional silver-filled ICAs. The topic of this study is the rheology of an epoxy filled with monodisperse polymer spheres with or without Ag coating. In trials with uncoated spheres, the viscosity increases with increasing sphere fraction, while the sphere diameter (6 vs. 30μm) only has a minor effect. With 45. vol% of spheres (giving an ICA with adequate electrical properties), the Ag coating on the spheres has a large effect on the rheology of the adhesive paste. Compared to the epoxy with uncoated spheres, the epoxy with Ag-coated spheres exhibits higher viscosity, higher storage and loss moduli, and a higher ratio of storage modulus to loss modulus (about 10. times). Furthermore, the viscosity of the epoxy with coated spheres increases with time in oscillatory measurements with low to intermediate frequencies. With hardener added to the epoxy containing Ag-coated spheres, the viscosity increase at room temperature is small within the first three hours. In curing trials, the viscosity development is different for unfilled and sphere-filled epoxies. The rheological properties of the ICA with 45. vol% Ag-coated spheres were found to be suitable for stencil/screen printing and dispensing processes. © 2012 Elsevier Ltd.


Nguyen H.-V.,Buskerud and Vestfold University College | Eggen T.,GE Vingmed Ultrasound AS | Aasmundtveit K.E.,Buskerud and Vestfold University College
20th European Microelectronics and Packaging Conference and Exhibition: Enabling Technologies for a Better Life and Future, EMPC 2015 | Year: 2015

Interconnection technology based on anisotropic conductive film (ACF) has been selected to assemble a transducer array on a flexible substrate in ultrasound imaging applications. The process of bonding and subsequently dicing a transducer on a flexible substrate was evaluated. The results show good integrity of ACF interconnects in test samples undergoing the assembly process. The interconnects, composed of a transducer element and a flex pad, retain high mechanical shear strength and low electrical resistance even after the tough dicing process. Furthermore, a high process yield promising for implementation in industry has been obtained. This work has demonstrated the feasibility of using ACF for assembling ultrasound transducers on system substrates. © 2015 IMAPS Europe.


Denarie B.,Norwegian University of Science and Technology | Torp H.,Norwegian University of Science and Technology | Bjastad T.,GE Vingmed Ultrasound AS
IEEE International Ultrasonics Symposium, IUS | Year: 2012

Multi-Line Transmission (MLT) is a potential approach to increase the framerate in 3D echocardiography, but suffers from artifacts caused by the cross-talk between the simultaneously transmitted beams. © 2012 IEEE.


Wang P.,Norwegian University of Science and Technology | Halvorsrod T.M.,GE Vingmed Ultrasound AS | Ytterdal T.,Norwegian University of Science and Technology
Electronics Letters | Year: 2014

An inverter-based ultra-low-power, low-noise, single-ended to differential continuous-time variable gain amplifier is presented for 2-6 MHz second harmonic cardiac imaging ultrasound probes in a 65 nm CMOS technology. The proposed variable gain amplifier (VGA) consists of three equal inverters and resistor arrays which form a feedback loop. To improve both the power and noise performances, the inverters operate in the sub-threshold region by adopting a 0.5 V supply voltage. By doubling the input transconductance of the VGA, the noise figure (NF) is enhanced further. The 6-b thermometer resistor arrays achieve a gain range of the VGA from 0 to 22 dB. The total power consumption is 55 μW, NF is 2.7 dB referred to an 8 kΩ source resistor at a centre frequency of 4 MHz. 8-b thermometer calibration codes are added into the inverters to force the static operating point of the inverters to half of the supply voltage, which could increase the immunity of the second harmonic distortion (HD2) to the process variation. The HD2 of the proposed VGA is -60.6 dB at the 330 mV peak-to-peak output swing. The active size is 154 × 102 μm. © The Institution of Engineering and Technology 2014.


Wang P.,Norwegian University of Science and Technology | Ytterdal T.,Norwegian University of Science and Technology | Halvorsrod T.,GE Vingmed Ultrasound AS
2013 European Conference on Circuit Theory and Design, ECCTD 2013 - Proceedings | Year: 2013

A low noise single-ended to differential linear two-stage switched capacitor variable gain amplifier (SC-VGA) is designed in a 0.18μm CMOS technology for 4MHz center frequency (fc) ultrasound imaging. To simplify the clock generator and improve linearity, the voltage sampling technique is adopted to replace the charge sampling for sake of the source impedance of piezo-electric transducers (PZT) not being as high as capacitive micro-machined ultrasonic transducers (CMUT) in ultrasound imaging systems. The two-stage VGA based on a single-stage OTA in each stage to save the power, and controlled by the 10-bit digital signals, has the maximum dB-in-linear gain varied from -14dB to 32dB. The first stage converts the single-ended input to differential outputs with a 2-bit 6dB/step coarse gain control varying from 0dB to 18dB, and the second stage has a fine gain control which exploits an 8b binary capacitor (CAP) array varying from -14dB to 14dB. For reducing the capacitance spread for a binary-weighted 8b (1:256) CAP array, the array is divided between the upper 4b and lower 4b by a divider capacitor. Simulation results show the core analog part of two-stage VGA consumes 900μA at 1.8V, has HD2 -61dB, HD3 -77dB at 190mV output Vpp, and the input referred noise (IRN) is √ at 4MHz at the maximum gain and a sampling frequency (fs) of 30MHz. The layout size is 387μm×502μm. © 2013 TU Dresden.


Wang P.,Norwegian University of Science and Technology | Ytterdal T.,Norwegian University of Science and Technology | Halvorsrod T.,GE Vingmed Ultrasound AS
2013 European Conference on Circuit Theory and Design, ECCTD 2013 - Proceedings | Year: 2013

A low noise single-ended to differential linear switched capacitor variable gain amplifier (SC-VGA) is designed in a 0.18μm CMOS technology for 4MHz center frequency (fs) 26-MHz ultrasound imaging. To fit the higher source impedance from gradually scaled piezo-electric transducers (PZT) in ultrasound imaging systems, a charge sampling amplifier with a fixed integration time as the first stage exhibits the lower noise, and higher sensitivity compared to the conventional voltage sampling amplifiers. The second voltage sampling stage converts the single-ended input to differential outputs with an exponential gain control which exploits an 8b binary capacitor (CAP) array, and the gain varies dB-in-linear from -14dB to 14dB. To reduce the capacitance spread for a binary-weighted 8b CAP array, the array is segmented between the upper 4b and lower 4b by a divider capacitor. Simulation results show the analog part of proposed amplifier consumes 1.25mA at 1.8V, has HD2 -62dB, HD3 -79dB at 150mV output Vpp, and the input referred noise (IRN) is 6.56pA/√Hz at 4MHz and 25.3nArms at a sampling frequency (fs) of 30MHz. The layout size is 310μm×370μm. © 2013 TU Dresden.


Wang P.,Norwegian University of Science and Technology | Ytterdal T.,Norwegian University of Science and Technology | Halvorsrod T.M.,GE Vingmed Ultrasound AS
2015 European Conference on Circuit Theory and Design, ECCTD 2015 | Year: 2015

This paper proposes two surfing architectures of the front-end for cardiac ultrasound imaging systems by removing the high voltage (HV) transmitter/receiver (Tx/Rx) switch in traditional ultrasound imaging systems, and connecting the input and the local ground of the Rx to the output of the Tx directly. Both advantages and challenges are presented. During the emitting phase, the Rx is on reset mode and voltages at all internal nodes in the Rx will follow the transmitting pulse, and this phenomenon exhibits the Rx is in the surf as the transmitting pulse. By removing the Tx/Rx switch, the Rx can avoid saturating status during the pulse emitting phase in Tx, and can receive the reflected echo signals in an efficient way after the emitting phase. While the input of the Rx connecting to the PZT transducer directly without the Tx/Rx switch, the received echo signals will not be distorted by the Tx/Rx switch, and the switched-capacitor (SC) front-end of the Rx can be relaxed in the design. Currently the bulk CMOS technology may not support this architecture because of its intrinsic process limitation and relatively large parasitic capacitance of the PN junctions. SOI CMOS technology could be a feasible CMOS technology because its parasitic capacitance of the PN junction is much smaller and its process is different from the bulk CMOS technology. The simulation is based on an inverter-based SC amplifier in a high voltage 0.18 μm 50 V/1.8 V bulk CMOS technology, and a HV switch is based on a model which cannot be implemented in a bulk CMOS technology. © 2015 IEEE.


Grant
Agency: European Commission | Branch: FP7 | Program: MC-ITN | Phase: FP7-PEOPLE-2012-ITN | Award Amount: 1.33M | Year: 2012

Every 30 second, a person in the Western world suffers sudden cardiac death and/or death from heart failure. These two conditions remain the major challenges in modern cardiology. However, new treatments now emerging offer hope in combating these events.Despite significant advances in new therapeutic approaches, current tools for risk stratification are insufficient, and treatment using ablation therapy or implantable pacemakers is often not optimized yielding less than satisfactory results. In order to bridge the gap between clinical needs and currently available technology for the assessment of cardiac dysfunction and its underlying etiology there is a need to develop competence in Europe within this area. Better tools for measuring and deriving cardiac deformation patterns, mechanical activation, electro-mechanical delay and accurate imaging guidance during electro-physiological ablation procedures have the potential to greatly improve the outcome for patients being treated for cardiac arrhythmias. The current key limiting factors to achieve this are: Immature and unreliable tools for tracking cardiac mechanical deformation Lack of tools for assessing electro-mechanical relationships in the heart Lack of researchers capable of operating across the integrated fields of ultrasound acquisition, image processing, visualization, cardiac electro-physiology, cardiology and interventional cardiology. Through training and knowledge development in a focused research project, USART will provide Europe with experienced researchers with the cross-disciplinary understanding and research skills necessary to develop enabling technologies in an industrial setting. The longer term outcome of the project is new products which will benefit patients across Europe directly by advancing the state of care related to these key issues within cardiology.

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