RU1838754C - Pressure pickup - Google Patents

Abstract

The invention relates to measuring technique, namely to measuring deformation of a material. The purpose of the invention is to expand (measuring the range at high pressure. The IHO device for use as a gas detector, an ultra-sensitive microphone, a pressure sensor, force, linear, acceleration, temperature and other similar devices as a unified transformer of deformation of a silicon membrane and an electric Signal Measurement with high accuracy of small displacements (from units to hundreds of angstroms) is achieved due to the effect of the tunneling current arising between the metal a hole located on the piezoelectric element and a silicon membrane. at small distances between them. By applying a high voltage to the X-axis of the piezoelectric element, the distance between the tip of the mist located on the mechanical axis Y of the piezoelectric element and the silicon membrane can be adjusted according to the size of the tunnel membrane current. 2 ill.

Description

i The invention relates to measuring technique, namely, to measuring the strain material made by microelectronic technology as a unified transformer of deformation into an electrical signal.

The purpose of the invention is to expand the measuring range on the side of small displacements-HIJIU and to increase the accuracy of measurements.

 This goal is achieved in that dg of fast dazlenie containing a membrane of electrically conductive silicon with a support base and a contact pad and a connected current output connected to it, is equipped with an insulating layer placed on the supporting base of the membrane, a copper plate mounted on an insulating

a layer, a piezoelectric element fixed to the plate with its ends, made 8 in the form of a rectangular parallelepiped, two current leads connected to the corresponding ends of the piezoelectric element, and a metal needle with a current outlet facing the membrane side fixed in the middle part of the piezoelectric element.

Fig. 1 is a structural diagram of a pressure sensor; Fig. 2 is a circuit diagram of a pressure sensor.

The pressure sensor comprises a membrane 1 made of a single crystal of silicon of the same type of conductivity, an ice element in the form of a parallelepiped 2 with a metal needle 3 fixed on it along the mechanical axis Y. The piezoelectric element 2 is attached with its &

DC 00 XI SL

B

with

with their ends on a copper plate 4 fixed on the insulating layer 5. On the electric axis X of the piezoelectric element 2, contact pads 6 with current leads 7 are applied. A contact pad 8 with current lead 9 is applied to the membrane 1, and a current lead 10 is connected to the metal needle 3.

The pressure sensor operates as follows (Fig. 2). In the initial state, the end of the metal needle 3 facing the membrane is installed at a small distance (from units to hundreds of angstroms) from the silicon membrane 1. If now we apply a voltage of the order of 1000 V from a controlled voltage source 11 along the electric axis of the piezoelectric element 2, the needle 3 will move along the mechanical axis Y in the direction of the membrane 1 by the distance necessary for the tunneling current to occur between the needle 3 and the membrane 1 along the current leads 9 and 10 from the reference voltage source 12.

In this way; by adjusting the high voltage from source 11, the initial value of the tunneling current can be selected. When exposed to any external factors, the silicon membrane 1 will deform in the direction of the needle 3. The tunnel current flowing through the load 13 is amplified by the amplifier 14 and through the feedback circuit 1.5 controls the voltage of the source 11, setting the tunneling current value by changing distance between membrane 1 and needle 3.

The change in the voltage of the controlled voltage source 11 corresponds to the movement of the membrane 1. Thus, in comparison with the prototype of the proposed

the sensor has new properties: it reduces the lower boundary of the measured strains by an order of magnitude and lower (to units of angstroms), i.e. increases sensitivity due to the effect of tunneling current; increases the accuracy of measurement due to the linearity of the scale, since small displacements of the membrane (units of tens of angstroms) correspond to a significant change in the voltage applied to the piezoelectric element (tens of hundreds of volts).

Claims (1)

 The formula for iso-6 reteni is a pressure sensor comprising a membrane of electrically conductive silicon with a support base and a contact pad, and the current output connected to it is distinguished by the fact that, in order to expand the measuring range towards low pressures, it is equipped with an insulating a layer, a copper plate, mounted on an insulating layer, a piezoelectric element, made in the form of a rectangular parallelepiped, mounted on the plate with its ends, two current outputs. connected to the corresponding ends of the piezoelectric element, and fixed in the middle part of the piezoelectric element facing the membrane with a metal needle with a current lead.  fS pv & 2