Development and post-dicing wet release of MEMS magnetometer: an approach

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Aditi ◽  
Supriyo Das ◽  
Ram Gopal
Keyword(s):  
Lorentz Force ◽  
Ambient Pressure ◽  
Magnetic Hysteresis ◽  
Laser Doppler Vibrometer ◽  
Anodic Bonding ◽  
Quality Factors ◽  
Wafer Level ◽  
Content Type ◽  
Positive Photoresist ◽  
Force Transduction

Purpose Si-based micro electro mechanical systems (MEMS) magnetometer does not require specialized magnetic materials avoiding magnetic hysteresis, ease in fabrication and low power consumption. It can be fabricated using the same processes used for gyroscope and accelerometer fabrication. The paper reports the dicing mechanism for the released MEMS xylophone magnetic sensor fabricated using wafer bonding technology and its characterization in ambient pressure and under vacuum conditions. The purpose of this paper is to dice the wafer bonded Si-magnetometer in a cost-effective way without the use of laser dicing and test it for Lorentz force transduction. Design/methodology/approach A xylophone bar MEMS magnetometer using Lorentz force transduction is developed. The fabricated MEMS-based xylophone bars in literature are approximately 500 µm. The present work shows the released structure (L = 592 µm) fabricated by anodic bonding technique using conducting Si as the structural layer and tested for Lorentz force transduction. The microstructures fabricated at the wafer level are released. Dicing these released structures using conventional diamond blade dicing may damage the structures and reduce the yield. To avoid the problem, positive photoresist S1813 was filled before dicing. The dicing of the wafer, filled with photoresist and later removal of photoresist post dicing, is proposed. Findings The devices realized are stiction free and straight. The dynamic measurements are done using laser Doppler vibrometer to verify the released structure and test its functionality for Lorentz force transduction. The magnetic field is applied using a permanent magnet and Helmholtz coil. Two sensors with quality factors 70 and 238 are tested with resonant frequency 112.38 kHz and 114.38 kHz, respectively. The sensor D2, with Q as 238, shows a mechanical sensitivity of 500 pm/Gauss and theoretical Brownian noise-limited resolution of 53 nT/vHz. Originality/value The methodology and the study will help develop Lorentz force–based MEMS magnetometers such that stiction-free structures are released using wet etch after the mechanical dicing.

scholarly journals A Resonant Pressure Microsensor with a Wide Pressure Measurement Range

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 382
Author(s):  
Chao Xiang ◽  
Yulan Lu ◽  
Chao Cheng ◽  
Junbo Wang ◽  
Deyong Chen ◽  
...  
Keyword(s):  
Chemical Mechanical Planarization ◽  
Measurement Range ◽  
Silicon On Insulator ◽  
Anodic Bonding ◽  
Pressure Measurements ◽  
Quality Factors ◽  
Deep Reactive Ion Etching ◽  
Wide Range ◽  
Form Pressure ◽  
Silicon Islands

This paper presents a resonant pressure microsensor with a wide range of pressure measurements. The developed microsensor is mainly composed of a silicon-on-insulator (SOI) wafer to form pressure-sensing elements, and a silicon-on-glass (SOG) cap to form vacuum encapsulation. To realize a wide range of pressure measurements, silicon islands were deployed on the device layer of the SOI wafer to enhance equivalent stiffness and structural stability of the pressure-sensitive diaphragm. Moreover, a cylindrical vacuum cavity was deployed on the SOG cap with the purpose to decrease the stresses generated during the silicon-to-glass contact during pressure measurements. The fabrication processes mainly contained photolithography, deep reactive ion etching (DRIE), chemical mechanical planarization (CMP) and anodic bonding. According to the characterization experiments, the quality factors of the resonators were higher than 15,000 with pressure sensitivities of 0.51 Hz/kPa (resonator I), −1.75 Hz/kPa (resonator II) and temperature coefficients of frequency of 1.92 Hz/°C (resonator I), 1.98 Hz/°C (resonator II). Following temperature compensation, the fitting error of the microsensor was within the range of 0.006% FS and the measurement accuracy was as high as 0.017% FS in the pressure range of 200 ~ 7000 kPa and the temperature range of −40 °C to 80 °C.

Role of interaction quality and trust in use of AI-based voice-assistant systems

2021 ◽  
Vol 23 (2) ◽  
pp. 154-170
Author(s):  
One-Ki Daniel Lee ◽  
Ramakrishna Ayyagari ◽  
Farzaneh Nasirian ◽  
Mohsen Ahmadian
Keyword(s):  
Information Quality ◽  
Success Factors ◽  
Survey Methodology ◽  
Research Model ◽  
System Quality ◽  
Quality Factors ◽  
Trust Mechanism ◽  
Content Type ◽  
Interaction Quality ◽  
Assistant Systems

PurposeThe rapid growth of artificial intelligence (AI)-based voice-assistant systems (VASs) has created many opportunities for individuals to use VASs for various purposes in their daily lives. However, traditional quality success factors, such as information quality and system quality, may not be sufficient in explaining the adoption and use of AI-based VASs. This study aims to propose interaction quality as an additional, yet more important quality measure that leads to trust in an AI-based VAS and its adoption. Design/methodology/approachThe authors propose a research model that highlights the importance of interaction quality and trust as underlying mechanisms in the adoption of AI-based VASs. Based on survey methodology and data from 221 respondents, the proposed research model is tested with a partial least squares approach. FindingsThe results suggest that interaction quality and trust are critical factors influencing the adoption of AI-based VASs. The findings also indicate that the impacts of traditional quality factors (i.e. information quality and system quality) occur through interaction quality in the context of AI-based VASs. Originality/valueThis research adds interaction quality as a new quality factor to the traditional quality factors in the information systems success model. Further, given the interactive nature of VASs, the authors use social response theory to explain the importance of the trust mechanism when individuals interact with AI-based VASs. Contribution to Impact

Wafer Level Micropackaging of MEMS Devices Using Thin Film Anodic Bonding

2002 ◽  
Vol 729 ◽  
Author(s):  
Lauren E. S. Rohwer ◽  
Andrew D. Oliver ◽  
Melissa V. Collins
Keyword(s):  
Shear Strength ◽  
Test Sample ◽  
Anodic Bonding ◽  
Mems Devices ◽  
Wafer Level ◽  
Thermal Actuators ◽  
Wafer Level Packaging ◽  
Hermetic Seal ◽  
Leak Testing ◽  
Before And After

AbstractA wafer level packaging technique that involves anodic bonding of Pyrex wafers to released surface micromachined wafers is demonstrated. Besides providing a hermetic seal, this technique allows full wafer release, provides protection during die separation, and offers the possibility of integration with optoelectronic devices. Anodic bonding was performed under applied voltages up to 1000 V, and temperatures ranging from 280 to 400°C under vacuum (10-4Torr). The quality of the bonded interfaces was evaluated using shear strength testing and leak testing. The shear strength of Pyrex-to-polysilicon and aluminum bonds was ∼10-15 MPa. The functionality of surface micromachined polysilicon devices was tested before and after anodic bonding. 100% of thermal actuators, 94% of torsional ratcheting actuators, and 70% of microengines functioned after bonding. The 70% yield was calculated from a test sample of 25 devices.

scholarly journals Building brand loyalty in e-commerce of fashion lingerie

2017 ◽  
Vol 21 (1) ◽  
pp. 103-114 ◽  
Author(s):  
Javier A. Sanchez Torres ◽  
Francisco-Javier Arroyo-Cañada
Keyword(s):  
Product Quality ◽  
Online Community ◽  
Virtual Community ◽  
Brand Strategy ◽  
Exploratory Research ◽  
Fashion Industry ◽  
Quality Factors ◽  
Content Type ◽  
Customer Perceptions ◽  
Electronic Shopping

Purpose The purpose of this paper is to know if the loyalty of online purchasing is determined by the final perceptions of product quality and brand reputation in the online community of lingerie customers. Design/methodology/approach The authors used an exploratory model which aspects in previous studies have evaluated satisfaction, loyalty and trust in electronic shopping, in order to examine whether the customer’s perception of the quality and innovation of the final product sold through e-commerce and reputation in the examined was made “Virtual Community” are key factors in creating loyalty. The sample was obtained from a lingerie company which sells its products in Europe in the website leonisa.com, the data were analysed with the software SmartPLS, validating the proposed relationships between customer perceptions on the purchased product and loyalty to the brand. Findings The results demonstrate theoretical conceptions regarding product characteristics (Quality, Innovation and Satisfaction), and constructs brand (Virtual Community, Reputation and Trust). Research limitations/implications This paper presents a case study for a specific brand as exploratory research in the lingerie industry, this must be validated with this type of product for other companies. Practical implications This research has elements of support for management, companies will turn attention to the satisfaction of consumers and to maintain goods levels of reputation in the virtual community. Social implications This research shows a real case of the correct implementation of brand strategy, detailing how customers are valued and therefore provides valuable information for customers and companies. Originality/value This exploratory study provides a new analysis of product quality factors that were not directly related to the loyalty of electronic purchasing, also, it allows the fashion industry to have elements of support for management and quality control, and that hypotheses relating to the product quality and loyalty in the electronic shopping is confirmed.

scholarly journals Optically read Coriolis vibratory gyroscope based on a silicon tuning fork

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
N. V. Lavrik ◽  
P. G. Datskos
Keyword(s):  
Tuning Fork ◽  
Microelectromechanical Systems ◽  
Ambient Pressure ◽  
Electrical Contacts ◽  
Wafer Level ◽  
Vibratory Gyroscopes ◽  
Equivalent Rate ◽  
Additional Processing ◽  
On Chip ◽  
Optical Lever

Abstract In this work, we describe the design, fabrication, and characterization of purely mechanical miniature resonating structures that exhibit gyroscopic performance comparable to that of more complex microelectromechanical systems. Compared to previous implementations of Coriolis vibratory gyroscopes, the present approach has the key advantage of using excitation and probing that do not require any on-chip electronics or electrical contacts near the resonating structure. More specifically, our design relies on differential optical readout, each channel of which is similar to the “optical lever” readout used in atomic force microscopy. The piezoelectrically actuated stage provides highly efficient excitation of millimeter-scale tuning fork structures that were fabricated using widely available high-throughput wafer-level silicon processing. In our experiments, reproducible responses to rotational rates as low as 1.8 × 103° h−1 were demonstrated using a benchtop prototype without any additional processing of the raw signal. The noise-equivalent rate, ΩNER, derived from the Allan deviation plot, was found to be <0.5° h−1 for a time of 103 s. Despite the relatively low Q factors (<104) of the tuning fork structures operating under ambient pressure and temperature conditions, the measured performance was not limited by thermomechanical noise. In fact, the performance demonstrated in this proof-of-principle study is approximately four orders of magnitude away from the fundamental limit.

Relationship between building maintenance sourcing strategy selection factors and performance

2019 ◽  
Vol 17 (2) ◽  
pp. 157-174 ◽  
Author(s):  
Khai Ying Soh ◽  
Shirley Jin Lin Chua ◽  
Azlan Shah Ali ◽  
Cheong Peng Au-Yong ◽  
Anuar Alias
Keyword(s):  
Maintenance Management ◽  
Quality Factors ◽  
Performance Measurements ◽  
Content Type ◽  
High Rise ◽  
Building Maintenance ◽  
Sourcing Strategy ◽  
Maintenance Work ◽  
And Performance ◽  
Selection Factors

Purpose The building maintenance management becomes more complicated nowadays, with several sourcing strategies springing up for building maintenance work provisions. Various studies demonstrate that the selection factors and performance measurements are both essential aspects in determining and evaluating the sourcing strategy for building maintenance management. Thus, the purpose of this paper is to examine the relationships between the selection factors and performance measurements of sourcing strategy. Design/methodology/approach The paper targeted to evaluate and analyse the perceptions of the building maintenance practitioners regarding the degree of importance of selection factors and performance measurements. Through quantitative approach, the paper adopted stratified random sampling to distribute the questionnaires to the building maintenance practitioners operating in both private and government high-rise office buildings in Kuala Lumpur. Findings The findings highlighted the quality factors as the most important selection group factors; meantime, the ability to fulfil client’s need and requirement as well as the ability to deliver the service with reasonable reliability and predictability are identically important performance measurements. There is a significant relationship between the selection factors and performance measurement of sourcing strategy. Originality/value This paper provides an impetus research which uncovered the sourcing practices in the industry and guided the sourcing process in determining the appropriate sourcing strategy.

Analysis of a circular microstrip antenna on isotropic or uniaxially anisotropic substrate using neurospectral approach

2013 ◽  
Vol 33 (1/2) ◽  
pp. 567-580 ◽  
Author(s):  
Sami Bedra ◽  
Siham Benkouda ◽  
Tarek Fortaki
Keyword(s):  
Resonant Frequency ◽  
Quality Factor ◽  
Microstrip Antenna ◽  
Numerical Results ◽  
Spectral Domain ◽  
Quality Factors ◽  
Resonant Frequencies ◽  
Content Type ◽  
Anisotropic Substrate ◽  
Circular Microstrip Antenna

Purpose – The paper aims to propose an artificial neural network (ANN) in conjunction with spectral domain formulation for fast and accurate determination of the resonant frequency and quality factor of circular microstrip antenna printed on isotropic or anisotropic substrate. This neurospectral approach reduces the problem complexity. Design/methodology/approach – The moment method implemented in the spectral domain provides good accuracy but its computational cost is high due to the evaluation of the slowly decaying integrals and the iterative nature of the solution process. The paper introduces the electromagnetic knowledge combined with ANN in the analysis of circular microstrip antenna on isotropic or uniaxially anisotropic substrate to reduce the complexity of the spectral approach and to minimize the CPU time necessary to obtain the numerical results. Findings – The resonant frequency results obtained from the neural model are in very good agreement with the experimental and theoretical results available in the literature. Finally, numerical results for the substrate anisotropy effect on the resonant frequency, quality factor and radiation pattern are also presented. Originality/value – The paper develops fast and accurate model based on ANN technique to calculate the resonant frequencies and quality factors of circular microstrip antennas. ANN is used to model the relationship between the parameters of the microstrip antenna and the resonant frequencies and quality factors obtained from the spectral domain approach. This relatively simple model allows designers to predict accurately the resonant frequencies and quality factors for a given design without having to develop or run the spectral method codes themselves. The main advantages of the method are: less computing time than the spectral model, results with accuracy equivalent to that of full-wave models and cost effectiveness, since the client can use a simple PC for implementation. Another advantage of the proposed ANN model is that it takes into account the uniaxial anisotropy in the substrate without increasing the network size. This is done by combining ANN with electromagnetic knowledge.

Effects of Packaging Induced Stress on MEMS Devices and Its Improvements

2006 ◽  
Vol 326-328 ◽  
pp. 529-532
Author(s):  
Sung Hoon Choa ◽  
Moon Chul Lee ◽  
Yong Chul Cho
Keyword(s):  
Silicon On Insulator ◽  
Anodic Bonding ◽  
Mems Devices ◽  
Wafer Level ◽  
Process Technology ◽  
Molding Compound ◽  
Mems Packaging ◽  
Induced Stress ◽  
Induced Structure ◽  
Glass Process

In MEMS, packaging induced stress or stress induced structure deformation becomes increasing concerns since it directly affects the performance of the device. The conventional MEMS SOI (silicon-on-insulator) gyroscope, packaged using the anodic bonding at the wafer level and EMC (epoxy molding compound) molding, has a deformation of MEMS structure caused by thermal expansion mismatch. Therefore we propose a packaged SiOG (Silicon On Glass) process technology and more robust spring design.

scholarly journals A Method of Fabricating Vacuum Packages with Vertical Feedthroughs in a Wafer Level Anodic Bonding Process

2014 ◽  
Vol 87 ◽  
pp. 887-890 ◽  
Author(s):  
Mustafa Mert Torunbalci ◽  
Said Emre Alper ◽  
Tayfun Akin
Keyword(s):  
Bonding Process ◽  
Anodic Bonding ◽  
Wafer Level
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