JPS6153872B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a differential pressure type semiconductor pressure transducer with symmetrical pressure versus output voltage characteristics.

In recent years, semiconductor pressure transducers have been proposed using IC technology to use a silicon plate itself as a diaphragm on which a diffusion gauge resistor is arranged, but among these, differential pressure type semiconductor differential force transducers have asymmetrical pressure vs. output voltage characteristics due to their structure. It had some drawbacks.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a semiconductor pressure transducer with symmetrical pressure versus output voltage characteristics.

In order to achieve such an object, the present invention arranges diffusion gauge resistors of the same type at the same positions on the first main surface and the second main surface of the diaphragm, and
One diffused gauge resistor on the principal surface and the diffused gauge resistors on the second principal surface, which are adjacent to each other on the first principal surface, are connected in series, and the two diffused gauge resistors connected in series are connected in series. At least four sets of gauge resistors are provided to form a bridge circuit, which will be described in detail below using examples.

FIG. 1 is a side view showing an embodiment of the pressure transducer used in the semiconductor pressure transducer according to the present invention, FIG. 2 is a plan view of FIG. 1, and FIG. 3 is the pressure transducer shown in FIG. 1. FIG. 2 is a wiring diagram showing an embodiment of the semiconductor pressure transducer according to the present invention. In the figure, 1 is a diaphragm thinned to a necessary thickness that can be handled, 2a to 2d are diffusion gauge resistors provided on the first main surface of this diaphragm 1 (see Figure 2), and 2c to 2h are diaphragms of this diaphragm 1. A diffusion gauge resistor provided on the second main surface; 3 is an adhesive material such as low melting point glass having a coefficient of thermal expansion comparable to that of the diaphragm 1; It is a support base for expansion rate.

In addition, the diffusion gauge resistors 2a to 2d and 2e to
2h has the same structure.

Next, since the pressure transducer with the above configuration has the support base 4 attached to only one side of the diaphragm 1, its pressure vs. output voltage characteristics are asymmetrical.
As shown in FIG. 3, diffusion gauges 2a, 2f, 2
b and 2e, 2c and 2h, and 2d and 2g are connected in series, that is, the diffused gauge resistor on the first principal surface and the diffused gauge resistor on the second principal surface adjacent to this diffused gauge resistor are connected in series. After the connection, the semiconductor pressure transducer according to the present invention can be constructed by wiring to a bridge circuit.

Next, the operation of the semiconductor pressure transducer having the above configuration will be explained.

First, when the first principal surface of the diaphragm 1 changes from concave to convex, for example, the resistance values of the diffusion gauge resistors 2a to 2d on the first principal surface change as shown by curve A in FIG. 4, and the output The voltage changes as shown by the dotted line in FIG. Simultaneously with this change, the second principal surface changes from convex to concave. Therefore, the resistance values of the diffusion gauge resistors 2e to 2h on the second principal surface change as shown by curve B in FIG.
It changes as shown by the dotted line in the figure. Since the diffusion gauge resistors 2a to 2h that change in this way are wired in a bridge circuit as shown in FIG. 3, the pressure versus output voltage becomes symmetrical as shown in FIG.

As described above in detail, the semiconductor pressure transducer according to the present invention has the effect of making its pressure vs. output voltage characteristics symmetrical with a simple configuration.

[Brief explanation of the drawing]

FIG. 1 is a side view showing an embodiment of a pressure transducer used in a semiconductor pressure transducer according to the present invention, FIG. 2 is a plan view of FIG. 1, and FIG. A wiring diagram showing one embodiment of the semiconductor pressure transducer according to the present invention, FIG. 4 is a diagram showing resistance change characteristics of each pressure transducer element shown in FIG. 1, and FIG. FIG. 3 is a diagram showing pressure versus output voltage characteristics of a pressure transducer. DESCRIPTION OF SYMBOLS 1... Diaphragm, 2a-2h... Diffusion gauge resistance, 3... Adhesive, 4... Support stand. Note that the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] 1. In a semiconductor pressure transducer whose diaphragm is a silicon plate on which a diffusion gauge resistor is arranged, diffusion gauge resistors of the same type are arranged at the same position on the first principal surface and the second principal surface of the diaphragm, and one diffused gauge resistor on the first major surface and the diffused gauge resistors on the second major surface that are located adjacent to each other on the first major surface are connected in series;
A semiconductor pressure transducer characterized in that at least four sets of the two series-connected diffusion gauge resistors are provided to constitute a bridge circuit to make pressure versus output voltage characteristics symmetrical. 2. Place a support base with a coefficient of thermal expansion similar to that of the diaphragm on the first main surface or the second main surface of the diaphragm.
The semiconductor pressure transducer according to claim 1, wherein the semiconductor pressure transducer is bonded to the main surface with an adhesive having a coefficient of thermal expansion comparable to that of the diaphragm.