JP3073079B2 - Absolute pressure sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absolute pressure sensor for detecting pressure by utilizing the piezoresistance effect of a semiconductor. More specifically, the present invention relates to an absolute pressure sensor in which a housing of a pressure sensor is shared with a gauge pressure sensor.

[0002]

2. Description of the Related Art Conventionally used absolute pressure type pressure sensors and gauge type pressure sensors use housings having different structures. The configuration of the two types of pressure sensors will be described with reference to FIGS. 3, 4, 5, and 6 attached. First, FIG. 3 is a sectional view of an absolute pressure sensor. The housing is composed of a pressure introducing side housing 1a and a pressure sealing side housing 2a.
And a sensor chip adhesive layer 3a is provided on the upper surface of the glass body base 14a, and the sensor chip 4 provided on the lower surface thereof is provided.
In a, a diaphragm 10a and a vacuum chamber 11a are formed.
In this case, the sensor chip 4a refers to a member incorporating a pressure-sensitive element or the like. The sensor chip 4a and the terminal 6a are connected by a gold wire 5a. A pressure introduction port 9a that communicates with the pressure sealing side housing 2a is provided in the pressure introduction side housing 1a.
Drilling. Fluid flowing from the pressure introduction port 9a is:
The pressure receiving region 8a indicated by the point group is filled. The absolute pressure of the fluid is measured by the sensor chip 4a based on the vacuum state of the vacuum chamber 11a. Usually, the distortion generated in the diaphragm 10a is taken out to the outside by an output terminal 6a connected to the gold wire 5a and converted into an electric signal. FIG. 4 shows a glass base 14a of the absolute pressure type pressure sensor shown in FIG.
FIG. 4 is a perspective view of a sensor chip 4a, a vacuum chamber 11a, and a diaphragm 10a formed in FIG. The pedestal 14a is disposed at a gap between the housings 1a and 2a as shown in FIG.

Next, a conventional gauge pressure type pressure sensor will be described with reference to FIGS. 5 and 6. FIG. The glass body pedestal 14b is housed in the cavity S formed by the pressure introducing side housing 1b and the pressure sealing side housing 2b. The sensor chip 4b constituting the pressure-sensitive element is disposed on the upper surface of the pedestal 14b to form the diaphragm 10b. A sensor chip adhesive layer 3b is provided on the lower surface. Sensor chip 4b
Is connected to an output terminal 6b by a gold wire 5b. The pressure introduction port 9b is bored in the pressure introduction side housing 1b,
It penetrates through the sensor chip adhesive layer 3b, extends to the pressure introduction hole 13b formed in the front surface of the pedestal 14b, and reaches below the diaphragm 10b of the sensor chip 4b. The fluid flowing from the pressure introduction port 9b fills the pressure receiving area 8b indicated by the point cloud, and the diaphragm 10b receives the pressure of the fluid and generates a distortion. The distortion is transmitted to the outside via the gold wire 5b and the output terminal 6b. It is extracted and converted into an electric signal. FIG. 6 is a perspective view of the pedestal 14b on which the sensor chip 4b and the like are formed in the gauge pressure type pressure sensor. A pressure introduction hole 13b is formed in the front surface of the pedestal 14b in the vertical direction.

[0004]

As will be understood from the above description,
The conventional absolute pressure type pressure sensor and the gauge pressure type pressure sensor employ different housings.
Therefore, housings having different configurations must be used in accordance with the type of the pressure sensor, so that there is a problem that it takes time to assemble related parts and strictly controls production.

[0005]

SUMMARY OF THE INVENTION Accordingly, the present invention uses a housing having the same structure as that of a gauge pressure type pressure sensor, and can be used as it is for assembling an absolute pressure type pressure sensor. Hereinafter, the configuration will be described. Pressure introducing side housing 1 and pressure sealing side housing 2
And a pedestal 14 provided with a diaphragm 10 and a vacuum chamber 11 on the surface and a horizontal pressure introducing groove 12 extending in the direction of the sensor chip 4 on the bottom surface, and a chip adhesive layer is formed on the lower surface of the pedestal. Absolute pressure type pressure sensor
The pedestal 14 is made up of a pressure introducing side housing 1b and an atmosphere opening hole 7b adopted in the gauge pressure type pressure sensor shown in FIG.
Is housed in the cavity S formed by the closed pressure sealing side housing 2b, so that the housings 1b and 2b of the gauge pressure type pressure sensor and the housings 1 and 2 of the absolute pressure type pressure sensor can be shared.

[0006]

According to the present invention, the pedestal of the absolute pressure type pressure sensor can be incorporated in the housing of the gauge pressure type pressure sensor as it is, so that the housing having the same configuration is used for both the gauge pressure type pressure sensor and the absolute pressure type pressure sensor. It is intended to reduce the production process and the production cost.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an absolute pressure type pressure sensor according to the present invention will be described below with reference to the accompanying drawings. FIG. 2 is a perspective view of the absolute pressure type pressure sensor according to the present invention, in which the sensor chip 4, the diaphragm 10, and the vacuum chamber 11 are formed on the pedestal 14. On the lower surface of the pedestal 14, a pressure introducing groove 12 extending horizontally in the direction of the sensor chip 4 is formed. The lower surface of the pressure introducing groove 12 is open. In the figure, reference numeral 10 denotes a diaphragm provided on the sensor chip 4, 11
Indicates a vacuum chamber. When the configuration of the pedestal 14 in FIG. 2 is compared with the diaphragm 10b and the pressure introducing hole 13b formed in the pedestal 14b of the gauge pressure type pressure sensor shown in FIG.
, A pressure introduction hole 13b extending vertically to the sensor chip 4b is formed in the front surface of the pedestal 14b, whereas in the absolute pressure type according to the present invention shown in FIG.
A pressure introducing groove 12 extending in the direction of the sensor chip 4 is formed on the lower surface of the base 14 so as to open downward. That is, the pressure introduction grooves 13b and 12 are different only in the position and the shape to be formed, and the pedestals 14b and 14 are exactly the same in size. The configurations of the housings 1 and 2 accommodating the absolute pressure type pressure sensors are the same as the housings 1b and 2b of the gauge pressure type pressure sensors. Therefore, by taking advantage of this structure, the pedestal 14 of the absolute pressure type pressure sensor can be accommodated in the cavity S formed by the pressure introducing side housing 1b and the pressure sealing side housing 2b of the gauge pressure type pressure sensor, and FIG. The pedestal 14b of the gauge pressure type pressure sensor can also be accommodated in a cavity S formed by the pressure introducing side housing 1 and the pressure sealing housing 2 of the illustrated absolute pressure type pressure sensor. In other words, by adopting a common housing having the same configuration, both the absolute pressure type pressure sensor and the gauge pressure type pressure sensor can be exchanged and manufactured very easily.

FIG. 1 is a sectional view showing a state in which a pedestal 14 shown in FIG. 2 is assembled to an absolute pressure type pressure sensor according to the present invention. In the drawing, reference numeral 1 denotes a pressure introduction housing, 2 denotes a pressure sealing housing, 3 denotes a sensor chip adhesive, 4 denotes a sensor chip, 5 denotes a gold wire, 6 denotes an output terminal, 8 denotes a pressure receiving area, 9 denotes a pressure introduction port, 10 Denotes a diaphragm, and 11 denotes a vacuum chamber. The components are the same as those of the gauge pressure type pressure sensor shown in FIG. 5 except that the vacuum chamber 11 is formed in the sensor chip 4 and the pressure introducing groove 12 is formed horizontally on the lower surface of the pedestal 14. Therefore, two types of pressure sensors can be easily formed by assembling the pedestal 14b shown in FIG. 6 and the pedestal 14 shown in FIG. Obtainable. However, when used as an absolute pressure sensor, the air opening hole 7b shown in FIG. 5 is of course closed.

[0009]

According to the present invention, the pedestal of the absolute pressure type pressure sensor and the pedestal of the gauge pressure type pressure sensor are replaced in the same housing cavity only by changing the drilling position of the pressure introduction groove provided in the pedestal. Therefore, there are effects such as labor saving of the production process and reduction of the production cost.

[Brief description of the drawings]

FIG. 1 is a sectional view of an absolute pressure sensor according to the present invention.

FIG. 2 is a perspective view of a pedestal employed in FIG. 1;

FIG. 3 is a cross-sectional view of a conventional absolute pressure sensor.

FIG. 4 is a perspective view of a pedestal employed in FIG. 3;

FIG. 5 is a sectional view of a conventional gauge pressure type pressure sensor.

FIG. 6 is a perspective view of a pedestal employed in FIG. 5;

[Explanation of symbols]

 S cavity 1 pressure introducing side housing 2 pressure sealing side housing 3 sensor chip bonding layer 4 sensor chip 7b atmosphere opening hole 8 pressure receiving area 9 pressure introducing port 10 diaphragm 11 vacuum chamber 12 pressure introducing groove 13b pressure introducing hole 14 pedestal

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01L 9/04 101 H01L 29/84

Claims (4)

(57) [Claims] 1. A pedestal provided with a diaphragm and a vacuum chamber on the surface and a horizontal pressure introduction groove extending in the sensor chip direction on the bottom surface in a cavity formed by the pressure introducing side housing and the pressure sealing side housing, Absolute pressure type pressure sensor with a chip adhesive layer formed on the lower surface of the base. 2. The gauge pressure type pressure sensor housing according to claim 2, wherein said pedestal is housed in a cavity formed by a pressure introducing side housing adopted as a gauge pressure type pressure sensor and a pressure sealing side housing having an atmosphere opening hole closed. 2. The absolute pressure sensor according to claim 1, wherein a housing of the absolute pressure sensor can be shared. 3. An absolute pressure sensor according to claim 1, wherein a chip adhesive layer is formed on a lower surface of said pedestal. 4. The absolute pressure type pressure sensor according to claim 1, wherein a pressure introducing groove is provided in a chip adhesive layer provided on a lower surface of the pedestal, instead of providing a pressure introducing groove on a bottom surface of the pedestal.