Quantification of Uncertainty in Creep Failure in RF-MEMS Switches

Author(s):  
Peter A. Kolis ◽  
Marisol Koslowski ◽  
Anil K. Bajaj

We present simulations of the dynamic response of radio frequency micro-electro-mechanical-systems (RF-MEMS) switches undergoing creep deformation. The model includes a microscale-informed Coble creep formulation incorporated in a beam model of an electrostatically actuated RF-MEMS switch, and it is solved using a Ritz-Galerkin based modal expansion. The resulting effects on the long-term device behavior as well as the implications of uncertainty in the device geometry and material parameters are studied. We find that the addition of creep to the beam model results in an undesired degradation of the device performance, as evidenced by decreases in the closing and release voltages.

2020 ◽  
Author(s):  
Lakshmi Swaminathan

RF (Radio Frequency) MEMS (Micro Electro Mechanical Systems) technology is the application of micromachined mechanical structures, controlled by electrical signals and interacting with signals in the RF range. The applications of these devices range from switching networks for satellite communication systems to high performance resonators and tuners. RF MEMS switches are the first and foremost MEMS devices designed for RF technology. A specialized method for fabricating microsturctures called surface micromachining process is used for fabricating the RF MEMS switches. Die level packaging using available surface mount style RF packages. The packaging process involved the design of RF feed throughs on the Alumina substrates to the die attachment, wire bonding and hermetic sealing using low temperature processes.


Author(s):  
S Girish Gandhi, I Govardhani, M Venkata Narayana, K Sarat Kumar

This is an attempt to compare three different shunt configured RF MEMS switches which offers a choice for applications in satellite and antennas. Advanced RF communication domain demands for design and modeling of RF MEMS switch which provides extremely reduced pull-in voltage, better isolation, low insertion loss, and with greater reliability. The proposed work manages with comparison of design modeling and performance of three different shunt configured RF MEMS switches. The proposed shunt configured RF MEMS switches are designed with different dimensions with different meandering techniques with perforations on beam structure helps in reducing the amount of voltage required for actuation of switch which is known as pull-in voltage. Comparative study of three different RF MEMS switches which involves in conducting electromechanical analysis are carried out using COMSOL multi physics tool and electromagnetic analysis are carried out using HFSS tool. Moreover the comparative study involves in comparing the values of pull-in voltage, switching time and capacitance, stress, insertion loss, return loss and isolation of three different RF MEMS switches. Proposed first switch model derives pull-in voltage of 16.9v with the switching time of 1.2µs, isolation of 47.70 dB at 5GHz and insertion loss of 0.0865 dB and return loss of 41.55 dB. Proposed second switch model derives pull-in voltage of 18.5v with the switching time of 2.5µs, isolation of 37.20 dB at 8GHz and insertion loss of 0.1177 dB and return loss of 38.60 dB. Proposed third switch model delivers pull-in voltage of 18.75v with the switching time of 2.56µs, isolation of 44.1552 dB at 8GHz and insertion loss of 0.0985 dB and return loss of 42.1004 dB.


Author(s):  
Kanthamani Sundharajan

Micro-electro mechanical systems (MEMS) technology has facilitated the need for innovative approaches in the design and development of miniaturized, effective, low-cost radio frequency (RF) microwave circuits and systems. This technology is expected to have significant role in today's 5G applications for the development of reconfigurable architectures. This chapter presents an overview of the evolution of MEMS-based subsystems and devices, especially switches and phased array antennas. This chapter also discusses the key issues in design and analysis of RF MEMS-based devices, particularly with primary emphasis on RF MEMS switches and antennas.


Author(s):  
Chris Brown ◽  
Jacqueline Krim ◽  
Art Morris

RF MEMS switch lifetimes are limited by stiction of the moving components and degradation of the metal to metal contact points during cycling. Currently, maximum switch lifetimes are around 10 to 25 billion cycles. Past experimentation has shown that some stiction problems can be overcome by carefully controlling the operating parameters, but problems at the contact points remain [1]. It is believed that by developing a set of tribological design rules which limit the factors leading to catastrophic failure, switches can operate in excess of 100 billion cycles. Recent research has quantified the reliability and durability of gold contact points on RF MEMS switches as a function of current [2]. Most experimentation on RF MEMS switches has focused on controlling the operating parameters such as current, voltage, electrode materials, contact area, switching mode and force; however, limited work has been performed on a single device type in multiple environmentally controlled testing conditions such as vacuum, cryogenic temperatures, etc. This presentation will discuss performance of the wiSpry RF MEMS switch focusing on quantification of device reliability and failure mechanisms under various atmospheric and temperature conditions. Environmental testing conditions include switching in open air, vacuum and inert gasses, in temperatures ranging from 294 K to 4 K.


2017 ◽  
Vol 26 (1) ◽  
pp. 283-294 ◽  
Author(s):  
Peter Kolis ◽  
Anil K. Bajaj ◽  
Marisol Koslowski

Author(s):  
Seung Min Yeo ◽  
Spyros I. Tseregounis ◽  
Andreas A. Polycarpou ◽  
Adam Fruehling ◽  
Dimitrios Peroulis

Topographical changes within the contact area as a function of cycling could be a critical factor causing failure and reliability issues in RF MEMS switch operation. In this paper, gold-to-gold contact, cantilever-type RF MEMS switches were tested (cold-switching mode) for different number of cycles, namely, 10, 102, 103, 104, 105, and 106. After the cycling tests, the contact area of each switch was scanned using optical microscopy, scanning electron microscopy and atomic force microscopy to quantify the exact gold-to-gold contact surface changes, leading to adhesion failures (at about 106 cycles). Detailed roughness analysis was carried out to better quantify topographical changes on the contact surface and relate them to failures. It was found that the material transfer from the top beam to the bottom substrate was dominant, and observed after only few cycles. Adhesion failure of gold-to-gold contact switches could be attributed to large protrusions formed on the bottom surface as the switch cycles over 105 times.


2014 ◽  
Vol 609-610 ◽  
pp. 1417-1421
Author(s):  
Chen Xu Zhao ◽  
Xin Guo ◽  
Tao Deng ◽  
Ling Li ◽  
Ze Wen Liu

This paper presents a novel approach to enhancing power-handling capability of metal-contact radio-frequency micro-electro-mechanical systems (RF MEMS) switches based on an Optimized Array Configured (OAC) contact dimples design. The simulation results reveal that this strategy can distribute the RF current more uniformly through each contact of the switch than traditional multiple parallel-configured contacts design, thus leading to a more effective reduction of current through each contact. Therefore, probability of micromelding and adhesion at metal contact point owing to localized high current induced Joule heating, which limits the power handling capability of the metal-contact RF MEMS switch, can be effectively reduced by the proposed approach. Comparing with previously fabricated switch, power-handling capability of the switch with OAC contact dimples can be dramatically improved over 390%.


Author(s):  
Isaku Kanno ◽  
Takaaki Suzuki ◽  
Hironobo Endo ◽  
Hidetoshi Kotera

This paper presents the possibility of piezoelectric RF-MEMS switches for low voltage operation. The switches we fabricated consist of micro-cantilevers using PZT thin films with the length of 490 μm and the width of 87 μm. The cantilevers are actuated as unimorph actuators that can be deflected by applying voltage between upper and lower electrodes. We could obtain large tip deflection of 3 μm even at the low voltage of 5.0V, which is well compatible with conventional IC drivers. This result indicates that the RF-MEMS switches using piezoelectric PZT thin films is advantageous to the low voltage switching devices in RF components compared with conventionally proposed electrostatic ones.


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