A Proposed Process to Fabricate Strain Gauge Directly Over the Sensor Substrate by Serigraphic Method

The main goal of this work is to characterize the strain gauges fabricated by serigraphic method aiming at its application in pressure sensors and load cells. The strain gauges are fabricated by serigraphic method: 316 L stainless steel and aluminum substrates in order to determine fabrication. The strain gauges fabricated over the aluminum substrate showed low sensibility due mainly to the low sheet resistance of the used paste A gauge factor between 2.8 and 14.6 were obtained for strain gauges fabricated over 316 L stainless steel substrates. It was observed a direct dependence of the gauge factor and the sheet resistance of the paste used to fabricate the strain gauge. A study was carried out in order to determine the dependence of the sensibility and electrical resistance with the thickness of resistive film using the serigraphic pastes which resulted in the best gauge factor(related to the number of serigraphic steps).It was verified that the electrical resistance increases with the number of sintering cycles.