A ceramic capacitive pressure microsensor with screen-printed diaphragm

Abstract

In this work, a ceramic capacitive sealed gauge pressure sensor has been designed, fabricated, and fully characterized for harsh environment pressure microsensor applications. Thick film screen printing has been expanded as a method for creating ceramic microstructures. The ceramic pressure microsensor consists of a bottom electrode deposited on a 96 % alumina substrate and a top electrode deposited on a ceramic diaphragm. The ceramic cavity and diaphragm were created using a thick film sacrificial layer. Hermeticity of the pressure sensor was characterized to assess the sensor's feasibility for MEMS applications such as harsh environment sealed gauge pressure sensors. The sensor showed excellent hermeticity with a maximum leak rate of 7.0 x 10 -10 atm cc/sec He after exposures to temperatures up to 500 o C. The sensor was also fully characterized up to 300 o C in a pressure range of 0 to 50 psi. The average sensitivity over these temperature and pressure ranges was 9.2 fF/psi.

Microsystems elements based on free-standing thick-films made with a new sacrificial layer process

“…However, the fabrication of thick-film actuators suffers from the lack of technological solutions for releasing the free-standing layers (also referred as structural layers), which have to be actuated separately from the substrate. Up to now, most suggested routes to solve this problem include the use of an epoxy-based sacrificial layer in the screen-printing process [3][4][5][6][7]. The authors underlined that processing parameters with carbon-based sacrificial layers have to be accurately chosen to obtain satisfactory results and that chemical etching may attack the structural layers when using glass or metal-based sacrificial layers.…”

A thick film screen-printed ceramic capacitive pressure microsensor for high temperature applications

“…The design incorporated a sacrificial layer, a common technique used to create cavities in the microelectromechanical systems (MEMS) industry, to create the required thick film cavity microstructure. The design has been described previously [11].…”

Miniaturized Planar Tomography for Multiphase Stagnant Sample Detection

“…In microdevices, most of the application utilizes planar electrode for microanalysis process [7]. Planar electrodes provide advantages such as scalability, inexpensive [8], highly controllable system [9], feasible for small particle detection and the ease of installation [10].…”