JPH10332519A - Characteristic measuring instrument for pressure sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the instrument which suppresses the generation of mechanical stress and can measure characteristics with high precision and high efficiency. SOLUTION: This instrument is a characteristic measuring instrument for measuring pressure characteristics of the pressure sensor and equipped with a pressure applying jig 2 which has a hollow part 21 inside and also has pressure intake holes 22 connected to the hollow part 21 and having a pressure intake pipe 17 inserted, a wiring board 4 on which a socket 5 where the pressure sensor can be mounted is mounted, and a support member 6 which supports the wiring substrate 4 elastically. Here, an external terminal 18 is mounted on the socket 5, the intake pipe 17 of the pressure sensor is inserted into the pressure intake hole 22 of the pressure applying jig 2, and pressure is applied to the pressure sensor main body 1 from the hollow part 21 of the pressure applying jig 2 through the pressure intake pipe 17; and an electric signal generated corresponding to the flexure of a diaphragm generated with the admitted pressure is led out of the external terminal 18 through the socket 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a characteristic measuring device for measuring a pressure characteristic of a pressure sensor.

[0002]

2. Description of the Related Art A pressure sensor chip having a diaphragm structure utilizes a piezo effect, and as shown in FIG. 2, a piezo resistor 12, a field oxide film 13, An electrode wiring 15 for extracting an electrode from the silicon nitride film 14 and the piezoresistor 12 is formed, and the semiconductor substrate 11 is anisotropically etched on the back side by an anisotropic etching technique.
A diaphragm 16 is formed. Then, these are covered with a cover to form a pressure sensor main body. A pressure sensor is composed of the pressure sensor main body and an external terminal connected to a pressure introducing pipe and electrode wiring 15 described later. Reference numeral 19 denotes an electrode pad that is in ohmic connection with the electrode wiring 15. The principle of operation of this pressure sensor is that when the diaphragm 16 bends under pressure, a stress corresponding to the amount of deflection is generated in the piezoresistor 12. The resistance value of the piezoresistor 12 changes according to this stress, and this is detected as a change in an electric signal.

[0003] The characteristics of this pressure sensor are that it uses silicon, so that it is smaller and more sensitive than the conventional Bourdon tube type, and it has good reproducibility and high reliability. can give.

[0004] Measuring equipment for measuring the pressure characteristics of such a pressure sensor generally includes a pressure generator, a constant voltage power supply or a constant current power supply, a voltmeter or an ammeter, a thermostat, and automatic control of these. And the like. Then, the pressure sensor to be measured is incorporated in a pressure applying jig for applying pressure, and is put in a constant temperature bath together with an output extracting unit for outputting a signal indicating a pressure characteristic from the pressure sensor to the outside. Various characteristics are measured in the temperature state.

Here, as shown in FIG. 3, the pressure applying jig 2 is made of a metal such as aluminum and has a hollow portion 21 therein.
It has a plurality of pressure introduction holes 22 connected to the hollow portion 21 and corresponding to the pressure introduction pipe 17 for introducing pressure to the diaphragm 16 in the pressure sensor main body 1. As the output take-out unit, a unit in which a plurality of IC sockets 31 are mounted on the wiring board 3 is used.

[0006] An external terminal 18 for taking out an electric signal of the pressure sensor to be measured to the outside is inserted into the IC socket 31 of the wiring board 3 so that the pressure introducing pipe 17 faces in the opposite direction to the wiring board 3 side. Next, the pressure applying jig 2 is mounted so that the pressure introducing pipe 17 fits into the pressure introducing hole 22. At this time, a stopper 32 as a spacer between the wiring board 3 and the pressure applying jig 2 is interposed therebetween. The stopper 32 is fixed to the wiring board 3 in advance, and the pressure applying jig 2 and the stopper 32 are fixed with the screw 23. The pressure applying jig 2 is provided with a pressure pipe 24, pressure is introduced from the pressure pipe 24 into the pressure introducing hole 22 through the hollow portion 21, and furthermore, the pressure sensor main body through the pressure introducing pipe 17. 1 to be introduced into the diaphragm 16.

[0007]

However, in the above-described method of measuring the pressure characteristics of the pressure sensor, the method for measuring the pressure characteristics of the pressure sensor is described as follows. When the positional displacement occurs in the direction, a stress mainly in the horizontal direction is applied to the pressure introducing pipe 17 by the pressure applying jig 2. This stress is applied to the diaphragm 16 in the pressure sensor main body 1, and the pressure characteristic changes. Further, since the pressure applying jig 2 is formed integrally so as to measure the characteristics of a plurality of pressure sensors with one pressure applying jig 2, the displacement of one pressure sensor becomes the whole displacement, Stress will also be applied to other pressure sensors.

Further, when the pressure applying jig 2 is fixed by a plurality of screws 23 and the tightening torque of the screws 23 varies, the pressure applying jig 2 slightly tilts and warps, There is a problem that the same stress as described above is applied to the pressure introducing pipe 17 of the sensor, and the pressure characteristics fluctuate.

Specifically, a stress of about 4 kgf / cm ² is applied to the pressure sensor main body 1 from the pressure applying jig 2, and it has been clarified that the offset voltage fluctuates by 1.2 mV due to this stress. .

Another problem is that the temperature characteristic such as temperature characteristic measurement is one of the important items among the characteristic items of the pressure sensor, but the efficiency of the temperature characteristic measurement is low. . In other words, in order to simultaneously measure a large number of pressure sensors with the integrated pressure applying jig 2, the volume of the pressure applying jig 2 increases, and the heat capacity thereof increases. In addition, since the pressure sensor to be measured is sealed by the wiring board 3, the pressure applying jig 2, and the stopper 32, even if the pressure characteristic is measured by changing the ambient temperature, It takes time for the temperature to change, and the efficiency of the measurement becomes poor.
In fact, the time required to measure the characteristics of the three temperatures (0 ° C., 25 ° C., 50 ° C.) is about 2 hours, and the time required for temperature rise and fall and stabilization is about 1.5 hours. , Account for a large proportion of the measurement time.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to provide a pressure sensor characteristic measuring apparatus capable of suppressing the occurrence of mechanical stress and measuring characteristics with high accuracy and high efficiency. Is to provide.

[0012]

According to the first aspect of the present invention,
Pressure of a pressure sensor having a pressure sensor main body, a pressure introducing pipe for introducing pressure to a diaphragm in the pressure sensor main body, and an external terminal for taking out an electric signal output according to the deflection of the diaphragm to the outside. A characteristic measuring device for measuring characteristics, comprising a pressure applying jig having a hollow portion therein, and having a plurality of pressure introducing holes connected to the hollow portion and into which the pressure introducing tube is inserted, and a socket to which a pressure sensor can be attached. And a support member for elastically supporting the wiring board. The external terminal is mounted on the socket, and a pressure introducing pipe of a pressure sensor is inserted into a pressure introducing hole of the pressure applying jig. And pressure is introduced into the pressure sensor body from the hollow portion of the pressure applying jig through the pressure introducing pipe, and the pressure is generated according to the deflection of the diaphragm caused by the introduced pressure. It is characterized in that an electrical signal from the external terminal was taken out through the socket.

According to a second aspect of the present invention, in the first aspect of the present invention, the support member is arranged in a vertical direction and a horizontal direction of the wiring board.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing a schematic configuration of a pressure sensor characteristic measuring device according to an example of an embodiment of the present invention. The pressure sensor characteristic measuring device of the present embodiment includes a wiring board 4, a support member 6, and a pressure applying jig 2.

On the wiring board 4, a socket 5 on which a pressure sensor can be mounted is mounted. The wiring board 4 is supported by a base 7 via a support member 6 having elasticity such as a spring. In the present embodiment, the wiring board 4 is supported by the support member 6 from the bottom surface 71 and the side surface 72 of the concave portion of the base 7. That is, the wiring board 4 is supported from the vertical direction and the horizontal direction.

The pressure applying jig 2 has a hollow portion 21 and is made of, for example, aluminum. Further, a pressure applying jig 2
Is formed with a pressure introducing hole (opening) 22 for connecting the pressure introducing pipe 17 of the pressure sensor. Although only one pressure introducing hole 22 is shown in FIG. 1, a plurality of pressure introducing holes 22 are formed so that the characteristics of a plurality of pressure sensors can be measured.

When the characteristic is measured by the pressure sensor characteristic measuring device of the present embodiment, first, the socket 5 mounted on the wiring board 4 supported by the support member 6 on the base 7 is externally mounted on the socket 5. The terminal 18 is mounted. Next, the pressure introducing pipe 17 of the pressure sensor is inserted into the pressure introducing hole 22 of the pressure applying jig 2. At this time, an O-ring 8 is interposed between the pressure introducing pipe 17 and the pressure introducing hole 22 and sealed to prevent pressure from leaking. In this state, the base 7 is put into a thermostat, maintained at a predetermined temperature, and pressure is introduced from a pressure pipe (not shown) through the hollow portion 21 of the pressure applying jig 2. The pressure is applied to the diaphragm 16 in the pressure sensor main body 1 via the pressure introducing pipe 17 of the sensor. By extracting an electric signal output from the external terminal 18 according to the pressure applied to the diaphragm 16 through the socket 5 connected to the external terminal 18, pressure characteristics can be measured.

According to the present embodiment, since the pressure sensor main body 1 mounted on the wiring board 4 via the socket 5 is held by the support member 6 having elasticity with respect to the base 7, the pressure sensor main body 1 Even if the external terminals 18 fluctuate due to the mechanical stress applied to the support member 6, the external terminals 18 are absorbed by the elasticity of the support member 6, and the mechanical stress in both the vertical direction and the horizontal direction is reduced. A pressure applying jig 2 is provided at an upper portion of the pressure sensor main body 1, but most of the pressure sensor main body 1 is exposed and is directly exposed to the atmosphere in the constant temperature bath. Therefore, when the pressure characteristic is measured by changing the ambient temperature in the constant temperature bath, the temperature of the pressure sensor changes following the change in the ambient temperature, so that the efficiency of the characteristic measurement does not deteriorate.

In this embodiment, the case where the wiring board 4 is installed in the concave portion of the base 7 has been described, but a flat base 7 may be used. Side 72 of
In order to cope with the above, a fixing portion for fixing a support member for horizontal support may be provided on the base 7.

[0020]

As described above, according to the first aspect of the present invention, the pressure sensor main body, the pressure introducing pipe for introducing pressure to the diaphragm in the pressure sensor main body, and the output according to the deflection of the diaphragm. A pressure sensor for measuring a pressure characteristic of a pressure sensor having an external terminal for taking out an electric signal to be output to the outside, wherein the pressure introduction pipe has a hollow portion therein and is connected to the hollow portion. A pressure applying jig having a plurality of pressure introducing holes into which a pressure sensor is inserted, a wiring board on which a socket on which a pressure sensor can be mounted is mounted, and a support member for elastically supporting the wiring board. Is mounted, a pressure introducing pipe of a pressure sensor is inserted into a pressure introducing hole of the pressure applying jig, and pressure is introduced into a pressure sensor main body from a hollow portion of the pressure applying jig via a pressure introducing pipe to conduct pressure. Since the electric signal generated in accordance with the deflection of the diaphragm caused by the applied pressure is taken out from the external terminal via the socket, even if a positional shift or the like occurs between the pressure supply pipe and the pressure sensor, The mechanical stress is absorbed by the supporting member having the elasticity, thereby suppressing the generation of the mechanical stress, and furthermore, most of the pressure sensor body is directly exposed to the atmosphere in the constant temperature bath, thereby achieving high precision and A pressure sensor characteristic measuring device capable of measuring characteristics with high efficiency was provided.

According to the second aspect of the present invention, in the first aspect of the present invention, if the support member is arranged in a vertical direction and a horizontal direction of the wiring board, the support member can be arranged in both the vertical and horizontal directions. Can suppress the generation of mechanical stress.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a cross-sectional state of a schematic configuration of a pressure sensor characteristic measuring device according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a cross section of a pressure sensor chip.

FIG. 3 is a schematic diagram showing a schematic configuration of a conventional pressure sensor characteristic measuring device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pressure sensor main body 2 Pressure application jig 4 Wiring board 5 Socket 6 Support member 7 Base 8 O-ring 16 Diaphragm 17 Pressure introduction pipe 18 External terminal 21 Hollow part 22 Pressure introduction hole 71 Bottom 72 Side

Claims (2)

[Claims] 1. A pressure sensor having a pressure sensor main body, a pressure introduction pipe for introducing pressure to a diaphragm in the pressure sensor main body, and an external terminal for taking out an electric signal output in accordance with the deflection of the diaphragm. A pressure measuring jig for measuring pressure characteristics of a pressure sensor comprising: a pressure applying jig having a hollow portion therein, and having a plurality of pressure introducing holes connected to the hollow portion and through which the pressure introducing pipe is inserted; and It has a wiring board mounted with a socket on which a sensor can be mounted, and a supporting member for elastically supporting the wiring board. The external terminal is mounted on the socket, and pressure is applied to a pressure introducing hole of the pressure applying jig. The pressure introduction pipe of the sensor is inserted, pressure is introduced into the pressure sensor main body from the hollow portion of the pressure applying jig through the pressure introduction pipe, and the deflection of the diaphragm caused by the introduced pressure is reduced. An electric signal generated in response to the electric signal is taken out from the external terminal through the socket. 2. The pressure sensor characteristic measuring device according to claim 1, wherein said support member is arranged in a vertical direction and a horizontal direction of said wiring board.