Silicon strain gages bonded on stainless steel using glass frit for strain sensor applications

Abstract

In this paper, a steel pressure sensor using strain gages bonded on a 17–4 PH stainless steel (SS) diaphragm based on glass frit technology is proposed. The strain gages with uniform resistance are obtained by growing an epi-silicon layer on a single crystal silicon wafer using epitaxial deposition technique. The inorganic glass frits are used as the bonding material between the strain gages and the 17–4 PH SS diaphragm. Our results show that the output performances of sensors at a high temperature of 125 °C are almost equal those at room temperature, which indicates that the glass frit bonding is a good method and may lead to a significant advance in the high temperature applicability of silicon strain gage sensors. Finally, the microstructure of the cured organic adhesive and the fired glass frit are compared. It may be concluded that the defects of the cured organic adhesive deteriorate the hysteresis and repeatability errors of the sensors.

Reciprocating Arc Silicon Strain Gauges

“…The development of semiconductor (piezoresistive) strain gauges provides a solution to the low-output problem of metal gauges, as they have a sensitivity up to 100 times greater than that of metallic gauges due to the piezoresistive effect [ 12 , 13 ]. Commercially available silicon strain gauges for diaphragm pressure sensors are designed with a single stain gauge [ 14 , 15 ] or half-bridge configurations [ 16 , 17 , 18 , 19 , 20 , 21 ], as shown in Figure 1 b,c. The half-bridge chip consists of two strain gauges and is very popular for commercial usage because of a reduced number of bonds to the steel diaphragm and faster installation.…”

Enhancement of Withstand Voltage in Silicon Strain Gauges Using a Thin Alkali-Free Glass

“…The vast majority of commercial force and pressure sensors today use Si piezoresistive strain gauges. Typically, these are made from p-type Si and are either manufactured as separate elements for bonding to the surface of a sensing diaphragm [5][6][7][8][9] or embedded into an Si sensing membrane [10][11][12][13] using the Si micro-electromechanical system (MEMS) process.…”

Bulk-micromachined, SOI-based half-bridge silicon strain gauges for high pressure applications

“…This leads to higher prices for most applications. Currently, two half-bridge strain gauge chips, each comprising two Si strain gauges and three bond pads, are positioned on the metal diaphragm in such a way that when pressure is applied to the diaphragm, one gauge from each die is put into tension and the other is put into compression [8,9].…”

“…This post-bond misalignment or chip breakage is due to the large mismatch between the coefficients of thermal expansion (CTE) of the metal diaphragm, glass frit, and silicon gauges. Some of these drawbacks are overcome by open strain gauges (see figure 2 in [8] and figure 1 in [11]). Open structures show a great improvement in glass-frit bonding strength and reliability [8].…”

“…Some of these drawbacks are overcome by open strain gauges (see figure 2 in [8] and figure 1 in [11]). Open structures show a great improvement in glass-frit bonding strength and reliability [8]. However, they are not easy to handle and use because they are very thin and extremely brittle.…”