scholarly journals Localized Bioimpedance Measurements with the MAX3000x Integrated Circuit: Characterization and Demonstration

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3013
Author(s):  
Shelby Critcher ◽  
Todd J. Freeborn

The commercial availability of integrated circuits with bioimpedance sensing functionality is advancing the opportunity for practical wearable systems that monitor the electrical impedance properties of tissues to identify physiological features in support of health-focused applications. This technical note characterizes the performance of the MAX3000x (resistance/reactance accuracy, power modes, filtering, gains) and is available for on-board processing (electrode detection) for localized bioimpedance measurements. Measurements of discrete impedances that are representative of localized tissue bioimpedance support that this IC has a relative error of <10% for the resistance component of complex impedance measurements, but can also measure relative alterations in the 250 mΩ range. The application of the MAX3000x for monitoring localized bicep tissues during activity is presented to highlight its functionality, as well as its limitations, for multi-frequency measurements. This device is a very-small-form-factor single-chip solution for measuring multi-frequency bioimpedance with significant on-board processing with potential for wearable applications.

Author(s):  
Stewart Smith ◽  
Hancong Wu ◽  
Jiabin Jia

This poster reports the design, implementation and testing of a portable and inexpensive bio-impedance measurement system intended for electrical impedance tomography (EIT) in cell cultures. The system is based on the AD5933 impedance analyser integrated circuit with additional circuitry to enable four-terminal measurement. Initial results of impedance measurements are reported along with an EIT image reconstructed using the open source EIDORS package.


1987 ◽  
Vol 108 ◽  
Author(s):  
Charles A. Steidel

ABSTRACTThere are three predominant interconnection technologies in use today for silicon integrated circuits: wire bonding; TAB (tape automated bonding); and C4 (controlled collapse chip connection). This paper briefly reviews each of these technologies for their strengths and weaknesses but focuses especially on wire bonding for single chip VLSI applications.Although wire bonding has been in widespread use ever since the invention of the small scale integrated circuit, the technique is still applicable for today's much larger and denser chips. With leadcounts up to 250 or even higher, many challenges are presented for equipment accuracy and speed and in package design, where novel techniques often are required to prevent the package from being the limiting factor in chip interconnection. These challenges are discussed in some detail.The paper concludes with a discussion of the future direction for mechanical connections as influenced by the technical and cost requirements of both the chip and the system in which it resides.


Author(s):  
S. Khadpe ◽  
R. Faryniak

The Scanning Electron Microscope (SEM) is an important tool in Thick Film Hybrid Microcircuits Manufacturing because of its large depth of focus and three dimensional capability. This paper discusses some of the important areas in which the SEM is used to monitor process control and component failure modes during the various stages of manufacture of a typical hybrid microcircuit.Figure 1 shows a thick film hybrid microcircuit used in a Motorola Paging Receiver. The circuit consists of thick film resistors and conductors screened and fired on a ceramic (aluminum oxide) substrate. Two integrated circuit dice are bonded to the conductors by means of conductive epoxy and electrical connections from each integrated circuit to the substrate are made by ultrasonically bonding 1 mil aluminum wires from the die pads to appropriate conductor pads on the substrate. In addition to the integrated circuits and the resistors, the circuit includes seven chip capacitors soldered onto the substrate. Some of the important considerations involved in the selection and reliability aspects of the hybrid circuit components are: (a) the quality of the substrate; (b) the surface structure of the thick film conductors; (c) the metallization characteristics of the integrated circuit; and (d) the quality of the wire bond interconnections.


Author(s):  
N. David Theodore ◽  
Donald Y.C Lie ◽  
J. H. Song ◽  
Peter Crozier

SiGe is being extensively investigated for use in heterojunction bipolar-transistors (HBT) and high-speed integrated circuits. The material offers adjustable bandgaps, improved carrier mobilities over Si homostructures, and compatibility with Si-based integrated-circuit manufacturing. SiGe HBT performance can be improved by increasing the base-doping or by widening the base link-region by ion implantation. A problem that arises however is that implantation can enhance strain-relaxation of SiGe/Si.Furthermore, once misfit or threading dislocations result, the defects can give rise to recombination-generation in depletion regions of semiconductor devices. It is of relevance therefore to study the damage and anneal behavior of implanted SiGe layers. The present study investigates the microstructural behavior of phosphorus implanted pseudomorphic metastable Si0.88Ge0.12 films on silicon, exposed to various anneals.Metastable pseudomorphic Si0.88Ge0.12 films were grown ~265 nm thick on a silicon wafer by molecular-beam epitaxy. Pieces of this wafer were then implanted at room temperature with 100 keV phosphorus ions to a dose of 1.5×1015 cm-2.


1997 ◽  
Vol 473 ◽  
Author(s):  
David R. Clarke

ABSTRACTAs in other engineered structures, fracture occasionally occurs in integrated microelectronic circuits. Fracture can take a number of forms including voiding of metallic interconnect lines, decohesion of interfaces, and stress-induced microcracking of thin films. The characteristic feature that distinguishes such fracture phenomena from similar behaviors in other engineered structures is the length scales involved, typically micron and sub-micron. This length scale necessitates new techniques for measuring mechanical and fracture properties. In this work, we describe non-contact optical techniques for probing strains and a microscopic “decohesion” test for measuring interface fracture resistance in integrated circuits.


2000 ◽  
Vol 631 ◽  
Author(s):  
J. G. Fleming ◽  
E. Chow ◽  
S.-Y. Lin

ABSTRACTResonance Tunneling Diodes (RTDs) are devices that can demonstrate very highspeed operation. Typically they have been fabricated using epitaxial techniques and materials not consistent with standard commercial integrated circuits. We report here the first demonstration of SiO2-Si-SiO2 RTDs. These new structures were fabricated using novel combinations of silicon integrated circuit processes.


Author(s):  
Mark Kimball

Abstract This article presents a novel tool designed to allow circuit node measurements in a radio frequency (RF) integrated circuit. The discussion covers RF circuit problems; provides details on the Radio Probe design, which achieves an input impedance of 50Kohms and an overall attenuation factor of 0 dB; and describes signal to noise issues in the output signal, along with their improvement techniques. This cost-effective solution incorporates features that make it well suited to the task of differential measurement of circuit nodes within an RF IC. The Radio Probe concept offers a number of advantages compared to active probes. It is a single frequency measurement tool, so it complements, rather than replaces, active probes.


Author(s):  
Carl Nail

Abstract To overcome the obstacles in preparing high-precision cross-sections of 'blind' bond wires in integrated circuits, this article proposes a different technique that generates reliable, repeatable cross-sections of bond wires across most or all of their lengths, allowing unencumbered and relatively artifact-free analysis of a given bond wire. The basic method for cross-sectioning a 'blind' bond wire involves radiographic analysis of the sample and metallographic preparation of the sample to the plane of interest. This is followed by tracking the exact location of the plane on the original radiograph using a stereomicroscope and finally darkfield imaging in which the wire is clearly visible with good resolution.


Author(s):  
Nicholas Randall ◽  
Rahul Premachandran Nair

Abstract With the growing complexity of integrated circuits (IC) comes the issue of quality control during the manufacturing process. In order to avoid late realization of design flaws which could be very expensive, the characterization of the mechanical properties of the IC components needs to be carried out in a more efficient and standardized manner. The effects of changes in the manufacturing process and materials used on the functioning and reliability of the final device also need to be addressed. Initial work on accurately determining several key mechanical properties of bonding pads, solder bumps and coatings using a combination of different methods and equipment has been summarized.


Author(s):  
Fenglei Du ◽  
Greg Bridges ◽  
D.J. Thomson ◽  
Rama R. Goruganthu ◽  
Shawn McBride ◽  
...  

Abstract With the ever-increasing density and performance of integrated circuits, non-invasive, accurate, and high spatial and temporal resolution electric signal measurement instruments hold the key to performing successful diagnostics and failure analysis. Sampled electrostatic force microscopy (EFM) has the potential for such applications. It provides a noninvasive approach to measuring high frequency internal integrated circuit signals. Previous EFMs operate using a repetitive single-pulse sampling approach and are inherently subject to the signal-to-noise ratio (SNR) problems when test pattern duty cycle times become large. In this paper we present an innovative technique that uses groups of pulses to improve the SNR of sampled EFM systems. The approach can easily provide more than an order-ofmagnitude improvement to the SNR. The details of the approach are presented.


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