SU1760412A1 - Semiconductor pressure transduce - Google Patents

Abstract

The invention relates to a measurement technique, in particular to the measurement of the pressure of liquid or gaseous media using miniature semiconductor pressure sensors. The purpose of the invention is to improve the measurement accuracy. To do this, in a semiconductor pressure transducer comprising a housing 1, a membrane 2 made of a semiconductor monocrystalline material in one piece with a support base 3 connected peripherally to the ring portion of the housing, an insulation board 6 in which rigid current leads 7 are attached. contact pads 9 along the inner circumference of the support base 3 and additionally perform the role of its supports.

Description

The invention relates to a measurement technique, in particular to the high-precision measurement of the pressure of liquid or gaseous media using miniature semiconductor pressure transducers.

Semiconductor pressure transducers are known with a sensitive element in the form of a membrane made of a semiconductor single crystal material in one piece with a support base attached to the housing from the side of tensometric elements arranged on the membrane. At the same time, contact pads from strain gauge elements are brought into the area of the support base and are electrically connected by thin flexible wires with rigid current leads fixed in the insulation board. One of the constructive schemes of the converter is to mount

membranes to its body along the periphery of the support base.

The disadvantage of such a solution is the significant stresses in the material of the body (and, accordingly, the elastic support base) caused by the distributed load g and the torque t arising from the measured pressure R. The figure, 1a is shown (simplified, without taking into account the stress concentration) zheniy og. in the cross section of the housing wall (the value of maximum stresses azmax is greater, the smaller the thickness h of the housing wall). These stresses, in turn, determine (due to the imperfections of the elastic properties of the material of the housing) the magnitude of one of the components of the transducer error, its sensitivity threshold. This error has a noticeable effect in the case of very accurate measurements achieved by the transducers with the semi-CO2

with

Vj o

§

fo

water sensing elements.

The purpose of the invention is to improve the accuracy of the converter (to reduce its sensitivity threshold),

For this, in addition to fastening the support base, along the periphery of the housing, a system of rigid supports of it is introduced (Fig. 16). These additional supports are rigid current leads fixed to the insulation board of the case, supporting an elastic membrane support base. In this case, the CTZmaxi voltage value is significantly reduced due to which the insensitivity error and the sensitivity threshold of the converter are reduced.

FIG. 2 shows one of the constructive solutions.

The semiconductor pressure transducer contains an annular part of the housing 1 with a sensing element in the form of a membrane 2 arranged on it, made of a semiconductor monocrystalline material in one piece with the supporting base 3 - a massive ring, on its periphery attached to the annular part of the converter housing 1, located on the membrane 2 current paths 4 and strain gauge elements 5. The connection of the support ring with the housing 1 seals the submembrane cavity from the measured medium. The insulation board 6 is axisymmetrically secured with several (e.g., twelve, sixteen, eighteen, etc.) current leads 7 (only two of them are shown in Fig. 2), and there is also a channel 8 for applying the reference pressure. Hard current leads 7, on which the sensitive element is supported by its contact pads 9, form the second (inner) circle of the supports of the massive ring.

The operation of the converter consists in the fact that under the influence of the measured pressure P membrane 2 is deformed and therefore the parameters of the strain gauge elements 5 (for example, the resistance of the strain gauges) change, and with the help of current-carrying tracks 4 and current leads 7 these changes of parameters are transmitted to the secondary measuring equipment.

Thus, using the invention in converters having a membrane made of a semiconductor single crystal material in one piece with a support base and attached to the converter housing from the strain gauge elements located on it, the accuracy of pressure measurements is reduced by reducing the voltage cross section

hull walls.

Claims (1)

Claims of the Invention A semiconductor pressure transducer comprising a housing with a sensing element located therein in the form of a membrane made of a semiconductor single crystal material integrally with a support base connected peripherally to the housing. located on the membrane of tekzometric elements, and an insulation board connected to the case, in which rigid current leads are fixed, with one end electrically connected to contact pads of strain gauge elements located on the supporting base, and others characterized in that with In order to increase the accuracy of pressure measurement, the membrane base is through it and is attached to the ends of rigid current leads through the contact pads. I I I 1 1 I I I I 1 czzzj one t 6, UHPH  J, JL mz -ShЈ-, bgrrffffl five 1 g s % FIG. Z