Oil-filled pressure sensor core body with overload protection

Abstract

The utility model discloses an oil-filled pressure sensor core with overload protection, which relates to the technical field of pressure sensor cores and comprises a base shell, a compression ring and a diaphragm, the compression ring is fixed at the lower end of the base shell, and the diaphragm is clamped between the lower end of the base shell and the upper end of the compression ring. A center channel of the base shell is sequentially provided with a base body, a ceramic gasket and an anti-overload cover from top to bottom, the base body is provided with a plurality of Kovar pipe legs, the ceramic gasket is provided with a pressure chip, each Kovar pipe leg is electrically connected with the pressure chip, the anti-overload cover is provided with a plurality of oil passing holes, and the oil passing holes are communicated with the pressure chip. An oil injection channel penetrates through the base body and the ceramic gasket, the upper end of the oil injection channel is located on the upper surface of the base body, the lower end of the oil injection channel is located on the lower surface of the ceramic gasket, and a pressure transmission medium is filled between the ceramic gasket and the diaphragm. According to the utility model, by additionally arranging the anti-overload cover, an anti-overload effect can be achieved, and the pressure chip can be protected.

Description

Technical Field

[0001] The utility model relates to the technical field of pressure sensor cores, in particular to an oil-filled pressure sensor core with overload protection. Background Art

[0002] Usually, MEMS silicon pressure sensors are further packaged because semiconductor silicon chips cannot directly contact corrosive or humid gas media. That is, the silicon chip is packaged in a cavity enclosed by a metal shell and a metal elastic membrane, and silicone oil is filled between the cavity and the metal elastic membrane. In this way, these corrosive or humid gas media will directly contact the metal elastic membrane material that can resist such media, and the pressure will be transferred to the silicone oil through the metal elastic membrane, and then transferred to the silicon chip through the silicone oil, thus realizing the conversion of pressure to resistance on the semiconductor silicon chip, thereby realizing the conversion of pressure signal into electrical signal.

[0003] However, in real applications, the medium usually has high-frequency pulsating pressure, or unpredictable excessive pressure is loaded on the metal elastic diaphragm, which is then transmitted to the silicon wafer, causing the silicon wafer to bear changes that exceed the elastic limit of the silicon wafer. In this way, the silicon wafer may cause unstable pressure measurement at the least, or even rupture and cause permanent damage.

[0004] Therefore, there is an urgent need in the art for an oil-filled pressure sensor core with overload protection to solve the above-mentioned problems. Utility Model Content

[0005] The purpose of the utility model is to provide an oil-filled pressure sensor core with overload protection to solve the problems existing in the above-mentioned prior art, and to play an overload protection role by adding an overload protection cover, thereby increasing the service life of the pressure chip.

[0006] To achieve the above purpose, the utility model provides the following solutions:

[0007] The utility model discloses an oil-filled pressure sensor core with overload protection, comprising a base shell, a pressure ring and a diaphragm, wherein the pressure ring is fixed to the lower end of the base shell, the diaphragm is clamped between the lower end of the base shell and the upper end of the pressure ring, the central channel of the base shell is provided with a base body, a ceramic gasket and an anti-overload cover in sequence from top to bottom, the base body is provided with a plurality of Kovar tube legs, a pressure chip is mounted on the ceramic gasket, each of the Kovar tube legs is electrically connected to the pressure chip, the anti-overload cover is provided with a plurality of oil holes, the base body and the ceramic gasket are penetrated by an oil injection channel, the upper end of the oil injection channel is located on the upper surface of the base body, the lower end of the oil injection channel is located on the lower surface of the ceramic gasket, and a pressure transmission medium is filled between the ceramic gasket and the diaphragm.

[0008] Preferably, two oil holes are provided.

[0009] Preferably, a steel ball is fixed at the oil inlet of the oil injection channel.

[0010] Preferably, the number of the Kovar tube legs is five.

[0011] Preferably, the base shell and the base body are fixed by welding;

[0012] The base shell and the pressure ring are fixed by welding.

[0013] Preferably, the Kovar tube leg and the pressure chip are connected by gold wire.

[0014] Compared with the prior art, the utility model has achieved the following technical effects:

[0015] The utility model adds an anti-overload cover between the pressure chip and the diaphragm, so as to prevent the diaphragm from making a large-scale displacement, thereby preventing the pressure chip from receiving an excessively large pressure value, thereby increasing the service life of the pressure chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 This is a schematic structural diagram of an oil-filled pressure sensor core with overload protection according to an embodiment of the utility model;

[0018] Figure 2It is a cross-sectional view of the core of the oil-filled pressure sensor with overload protection according to an embodiment of the utility model;

[0019] Figure 3 It is a front view of the core of the oil-filled pressure sensor with overload protection according to an embodiment of the utility model;

[0020] Figure 4 A top view of an oil-filled pressure sensor core with overload protection according to an embodiment of the utility model;

[0021] In the figure: 1-base shell; 2-base body; 3-Kovar tube leg; 4-oil injection channel; 5-steel ball; 6-ceramic gasket; 7-pressure chip; 8-anti-overload cover; 9-pressure ring; 10-diaphragm. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0023] The purpose of the utility model is to provide an oil-filled pressure sensor core with overload protection to solve the problems existing in the above-mentioned prior art, and to play an overload protection role by adding an overload protection cover, thereby increasing the service life of the pressure chip.

[0024] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0025] like Figure 1-Figure 4As shown, the utility model provides an oil-filled pressure sensor core with overload protection, including a base shell 1, a pressure ring 9 and a diaphragm 10, wherein the pressure ring 9 is fixed to the lower end of the base shell 1, and the diaphragm 10 is sandwiched between the lower end of the base shell 1 and the upper end of the pressure ring 9. The central channel of the base shell 1 is provided with a base body 2, a ceramic gasket 6 and an anti-overload cover 8 from top to bottom, wherein a plurality of Kovar tube legs 3 are provided on the base body 2, specifically, a plurality of tube leg through holes are provided on the base body 2, and the Kovar tube legs 3 are respectively inserted into the corresponding tube leg through holes and fixed by sintering glass powder. A pressure chip 7 is installed on the ceramic gasket 6, and the pressure chip 7 is installed in the central groove of the ceramic gasket 6, and each Kovar tube leg 3 is electrically connected to the pressure chip 7. The anti-overload cover 8 is provided with a plurality of oil holes, and an oil injection channel 4 is penetrated through the base body 2 and the ceramic gasket 6. The upper end of the oil injection channel 4 is located on the upper surface of the base body 2, and the lower end of the oil injection channel 4 is located on the lower surface of the ceramic gasket 6. The ceramic gasket 6 and the diaphragm 10 are filled with a pressure transmission medium, which is silicone oil, and the pressure transmission medium is injected through the oil injection channel 4.

[0026] In actual use, external pressure will be applied to the diaphragm 10 through the central through hole of the pressure ring 9. The diaphragm 10 will deform after sensing the external pressure. After the diaphragm 10 is deformed, it will push the pressure transmission medium through the oil hole and squeeze the pressure chip 7, that is, the pressure generated by the deformation of the diaphragm 10 will be transmitted to the pressure chip 7 through the pressure transmission medium. After the pressure chip 7 detects the pressure value, it transmits the relevant data to the control terminal or controller through the Kovar tube leg 3. When the external pressure is too large, the deformation of the diaphragm 10 will also increase. When the pressure reaches a certain threshold, the diaphragm 10 bulges upward and contacts the anti-overload cover 8, so that the force on the pressure transmission medium also reaches the maximum threshold and will not increase further, thereby achieving the technical effect of protecting the pressure chip 7.

[0027] In this embodiment, two oil holes are provided, and those skilled in the art may also adjust the size and number of the oil holes according to actual needs.

[0028] In this embodiment, a steel ball 5 is welded and fixed at the oil inlet of the oil injection channel 4. After the staff fills the gap between the diaphragm 10 and the ceramic gasket 6 with silicone oil through the oil injection channel 4, the steel ball 5 is used to weld and seal the oil injection port of the oil injection channel 4 to prevent subsequent silicone oil leakage.

[0029] In other embodiments, the steel ball 5 may also be replaced by a pin or other structure, as long as the structure can seal the oil injection channel 4 .

[0030] In this embodiment, there are five Kovar tube legs 3, and those skilled in the art may also set it to six or more, and the number is not limited to this one.

[0031] In this embodiment, the base shell 1 and the base body 2 are fixed by welding.

[0032] Similarly, the base shell 1 and the pressure ring 9 are also fixed by welding, which is simple to construct and firmly fixed.

[0033] In this embodiment, the Kovar tube leg 3 and the pressure chip 7 are connected by gold wires to achieve transmission of electrical signals, and the pressure chip 7 can be made of an existing silicon chip.

[0034] The present invention uses specific examples to illustrate the principle and implementation of the present invention. The above examples are only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An oil-filled pressure sensor core with overload protection, characterized in that: It includes a base shell, a pressure ring and a diaphragm, the pressure ring is fixed to the lower end of the base shell, the diaphragm is clamped between the lower end of the base shell and the upper end of the pressure ring, the central channel of the base shell is provided with a base body, a ceramic gasket and an anti-overload cover from top to bottom, the base body is provided with a plurality of Kovar tube legs, the ceramic gasket is installed with a pressure chip, each of the Kovar tube legs is electrically connected to the pressure chip, the anti-overload cover is provided with a plurality of oil holes, the base body and the ceramic gasket pass through an oil injection channel, the upper end of the oil injection channel is located on the upper surface of the base body, the lower end of the oil injection channel is located on the lower surface of the ceramic gasket, and the ceramic gasket and the diaphragm are filled with a pressure transmission medium.

2. The oil-filled pressure sensor core with overload protection according to claim 1, characterized in that: There are two oil holes.

3. The oil-filled pressure sensor core with overload protection according to claim 1, characterized in that: A steel ball is fixed at the oil inlet of the oil injection channel.

4. The oil-filled pressure sensor core with overload protection according to claim 1, characterized in that: The Kovar tube legs are provided with five.

5. The oil-filled pressure sensor core with overload protection according to claim 1, characterized in that: The base shell and the base body are fixed by welding; The base shell and the pressure ring are fixed by welding.

6. The oil-filled pressure sensor core with overload protection according to claim 1, characterized in that: The Kovar tube legs and the pressure chip are connected via gold wires.

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