Silicon membranes to create pressure transducers are used widely enough, well studied strain effect in the membranes with different crystallographic orientations, Technologies of working with them, create them tensoresistive sensors and connect them into integrated circuits inclusion. The use of silicon and advanced microelectronics technologies allow the creation of small size pressure sensors for applications in medicine and other special solutions of problems in various fields of science and technology.
Consider one of the well-known integral tensoresistive absolute pressure transducers in the literature. It has a structure as depicted in Figure 1. The design consists of a flat glass cover, in which the etched groove, and a silicon crystal with a thin membrane, which produced four gage connected in a bridge circuit. Membrane surrounded by a thick silicon ring base. Indentation in the glass plate is located under the diaphragm, and the plate itself is sealed with a silicon crystal using anodic landing. The anode connection is made by heating the glass and the silicon plate to 400 ° C, followed by applying a voltage to 600 V on silicon respect to a ground glass plate. The anode is a totally fit tight connection, making hole in a glass plate with a membrane forms a closed sealed chamber.
External dimensions of the converter: 1.5 x2, 0x0, 2 mm. Sensitivity of 0.2 mV / (kPa⋅V). Temperature drift is equivalent to 250 Pa for 1 ° C The output voltage varies linearly to the pressure of 40 kPa.
Fig.1. The structure of the silicon integrated absolute pressure transducer: