Bonding Packaging of a SP4T RF MEMS Switch

Abstract

A study on bonding packaging of a SP4T series RF MEMS switch with metal-to-metal contact is presented. The switch, with the total die size of 3580pm x2740gm, consists of a coplanar waveguide (CPW), SiON dielectric bridge membranes and broadside actuation electrodes. In order to protect the movable structures from the mechanical damage as well as the particle contaminations, a high-resistivity silicon cap with a rectangular cavity of 50pm depth is designed, fabricated via etching in KOH solution at 800 C, and bonded on top of the switch with epoxy resin. The results show the bonding between the cap and the switch support substrate is mechanically robust and the degradation of the isolation is in the range of 5%-010% in the frequency band from 1-10 GHz.

Metal‐bonding‐based hermetic wafer‐level MEMS packaging technology using in‐plane feedthrough: Hermeticity and high frequency characteristics of thick gold film feedthrough

“…[2][3][4][5][6][7][8][9][10][11][12][13][14] In so doing, leads must be drawn while maintaining vacuum, which is a problem especially in RF MEMS using low-resistance thick Au lines. 1 With high-frequency (RF) MEMS switches, internal space is usually retained in vacuum to prevent degradation of electric contacts, or to maintain switching speed through suppression of aid damping.…”

“…1 With high-frequency (RF) MEMS switches, internal space is usually retained in vacuum to prevent degradation of electric contacts, or to maintain switching speed through suppression of aid damping. [2][3][4][5][6][7][8][9][10][11][12][13][14] In so doing, leads must be drawn while maintaining vacuum, which is a problem especially in RF MEMS using low-resistance thick Au lines.Cap wafer bonding using glass frit, 5,15,16 feedthrough glass substrates, 7,17 anodic bonding of LTCC (Low Temperature Cofired Ceramic) substrates, 19,20 and other methods are long known techniques for wafer-level hermetic packaging of RF MEMS. The technique using glass frit is simple and convenient.…”

Low Actuating Voltage Spring-Free RF MEMS SPDT Switch

“…In the ON state, overlap capacitance is 2.01 pF and parasitics have a negligible effect on it. Insertion loss lies in the range of −0.3 dB to −0.6 dB for a wide bandwidth of 19 (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) GHz. Isolation varies from −28.1 dB (@1 GHz) to −20 dB (@20 GHz) as shown in Figure 7.…”

“…The RF MEMS devices are known to be better compared to solid state devices due to their low power consumption, high isolation, and low insertion loss. RF MEMS SPDT switches constitute the basic building block of the RF MEMS systems like SP4T [1], phase shifter [2], switch matrix [3], other communication systems [4], and so forth. The RF MEMS devices are also known to have few drawbacks too, for example, low switching speed (20-200 sec), high pull-in voltage (15-80 V), larger size, and reliability [5,6].…”