CN215492215U - Medium isolation type pressure sensor - Google Patents
Medium isolation type pressure sensor Download PDFInfo
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- CN215492215U CN215492215U CN202121798659.8U CN202121798659U CN215492215U CN 215492215 U CN215492215 U CN 215492215U CN 202121798659 U CN202121798659 U CN 202121798659U CN 215492215 U CN215492215 U CN 215492215U
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- pressure sensor
- top cover
- side wall
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Abstract
The utility model provides a medium-isolated pressure sensor, comprising: a substrate; the shell comprises a side wall and a top cover, the side wall is hermetically connected with the top cover, the side wall is made of a hard material, the top cover is made of a flexible material, and the shell is buckled on the substrate to form an accommodating cavity; the pressure sensor chip is fixed on the substrate and is arranged in the accommodating cavity; and the medium liquid is filled in the accommodating cavity, and the external pressure can be conducted to the pressure sensor chip through the shell and the medium liquid. The utility model has the advantages that the shell comprises the side wall made of hard materials and the top cover made of flexible materials, the measurement precision and the supporting force can be balanced, the reliability is considered, the output of the medium isolation type pressure sensor is ensured, the defect caused by a single shell material can be avoided, and the performance of the medium isolation type pressure sensor is greatly improved.
Description
Technical Field
The utility model relates to the field of sensor packaging, in particular to a medium isolation type pressure sensor.
Background
According to different working principles, pressure sensors can be mainly classified into piezoresistive, capacitive, resonant, piezoelectric, optical fiber and other pressure sensors; the MEMS piezoresistive pressure sensor based on the MEMS system has a small size, a light weight, a high sensitivity, a stability, a reliability, a low cost, a simple manufacturing process, and a convenient integration, and thus becomes a mainstream technology of the pressure sensor chip.
The general packaging form of the MEMS piezoresistive pressure sensor is that a pressure sensitive chip is sealed on a metal tube shell or a plastic tube shell in a direct bonding or glass transition bonding mode, then electric connection is realized through a gold wire or an aluminum wire, and a pressure sensitive unit of the MEMS piezoresistive pressure sensor is in direct contact with a measuring medium and is suitable for pressure measurement of a clean and clean gas medium without corrosiveness.
However, in the environment with severe application environment and more pollutants, such as automobile engine oil, air conditioner refrigerants, brakes and the like, the medium to be detected cannot be in direct contact with the pressure sensor chip. A special packaging technology is needed to isolate the medium to be measured from the pressure sensor chip and to realize the pressure transmission function.
However, the existing medium-isolated pressure sensor is difficult to automatically package and calibrate and test in a large scale, is expensive, cannot be miniaturized, and cannot meet the requirements of users.
SUMMERY OF THE UTILITY MODEL
The utility model aims to solve the technical problem of providing a medium isolation type pressure sensor.
In order to solve the above problems, the present invention provides a media isolated pressure sensor, comprising: a substrate; the shell comprises a side wall and a top cover, the side wall is hermetically connected with the top cover, the side wall is made of a hard material, the top cover is made of a flexible material, and the shell is buckled on the substrate to form an accommodating cavity; the pressure sensor chip is fixed on the substrate and is arranged in the accommodating cavity; and the medium liquid is filled in the accommodating cavity, and the external pressure can be conducted to the pressure sensor chip through the shell and the medium liquid.
Optionally, the end of the top cover is bonded to the side of the side wall by an adhesive layer.
Optionally, the top cover includes a connecting portion and a cover plate, the connecting portion is disposed at an end of the top cover and extends in a direction parallel to the side wall, and the cover plate is located between the connecting portions.
Optionally, the connecting portion and the cover plate form a concave configuration or an inverted C-shaped configuration, and the connecting portion and the cover plate are integrally formed.
Optionally, the top cover is made by a rubber vulcanization process, and the thickness of the top cover is less than 2 mm.
Optionally, an oil filling hole is formed in the base plate, the oil filling hole is communicated with the accommodating cavity, and a sealing material is filled in the oil filling hole.
Optionally, the outer surface of the side wall is provided with a groove for placing a sealing ring.
The medium isolation type pressure sensor has the advantages that the shell of the medium isolation type pressure sensor comprises the side wall made of hard materials and the top cover made of flexible materials, the measuring precision and the supporting force can be balanced, the reliability is considered, the output of the medium isolation type pressure sensor is ensured, the defects caused by a single shell material can be avoided, and the performance of the medium isolation type pressure sensor is greatly improved.
Drawings
FIG. 1 is a schematic diagram of a media-isolated pressure sensor according to a first embodiment of the present invention;
FIG. 2 is a schematic diagram of a media-isolated pressure sensor according to a second embodiment of the present invention
FIG. 3 is a schematic diagram illustrating steps in a method of making a media isolated pressure sensor according to a third embodiment of the present invention;
fig. 4A to 4D are process flow diagrams of forming a housing in a method for manufacturing a dielectric isolation type pressure sensor according to a third embodiment of the utility model.
Detailed Description
The following describes in detail a specific embodiment of the media-isolated pressure sensor according to the present invention with reference to the accompanying drawings.
Fig. 1 is a schematic structural diagram of a media-isolated pressure sensor according to a first embodiment of the present invention, and referring to fig. 1, the media-isolated pressure sensor according to the present invention includes a substrate 10, a housing 20, at least one pressure sensor chip 30, and a medium liquid.
The substrate 10 includes, but is not limited to, a ceramic circuit board or a printed circuit board. Electrical connection lines are provided in the substrate 10 to electrically connect the pressure sensor chip 30 with the outside. For example, in the present embodiment, the substrate 10 is a ceramic circuit board, and an electrical connection line (not shown) is disposed therein to electrically connect the pressure sensor chip 30 with an external structure.
The housing 20 is fastened to the substrate 10, and forms an accommodating cavity 11 with the substrate 10. The housing 20 includes a sidewall 21 and a top cover 22.
The side wall 21 is a closed frame, and the top and the bottom of the side wall are hollow structures. The top of the side wall 21 is used for being hermetically connected with the top cover 22, and the bottom of the side wall 21 is used for being hermetically connected with the substrate 10. In the present embodiment, the sidewall 21 has an annular closed configuration, while in other embodiments of the present invention, the sidewall 21 may have a square closed configuration or a polygonal closed configuration, which is not limited by the present invention.
The side wall 21 is made of a hard material, which may be metal or hard plastic, for support. For example, in the present embodiment, the side wall 21 is made of a metal material, which serves as a support structure of the housing, so that the housing 20 and the substrate 10 can form the accommodating chamber 11.
The top cover 22 is connected to the top of the side wall 21. The cap 22 is made of a flexible material and functions as a force conductor. When external pressure is applied to the medium-isolated pressure sensor, the top cover 22 can deform under the external pressure, so that the external pressure is transmitted to the pressure sensor chip, and pressure sensing is realized. The flexible material may be rubber, silicone, or the like, for example, in this embodiment, the flexible material is rubber.
Further, the end of the top cover 22 is bonded to the side of the side wall 21 by an adhesive layer 23. The bonding layer 23 can be a structure formed by adhesives such as glue and the like which have good sealing effect and are not easy to age.
Further, in the present embodiment, the top cover 22 includes a connecting portion 221 and a cover plate 222.
The connection portion 221 is disposed at an end portion of the top cover 22 and is sealingly connected to an inner surface of the side wall 21 by an adhesive layer 23. Further, the connection part 221 extends in a direction parallel to the side wall 21 to increase a contact area between the top cover 22 and the side wall 21, so that the firmness of combination of the top cover and the side wall is increased, and the performance of the medium-isolated pressure sensor is improved.
The cover plate 222 is located between the connection parts 221. In this embodiment, the cover plate 222 has a circular configuration, and the circumference thereof can be connected to the connecting portion 221 to form an integrated top cover 22. That is, the cover plate 222 is integrally formed with the connection part 221.
Further, in the present embodiment, the connection portion 221 and the cover plate 222 form a concave configuration and are integrally formed. The connecting portion 221 is disposed around the sidewall 21, and is connected to the sidewall 21 through the adhesive layer 23 in a sealing manner. The cover plate 222 is provided inside the connection portion 221 as a pressure transmission member.
In other embodiments of the present invention, the connecting portion 221 and the cover plate 222 may have other configurations. Specifically, please refer to fig. 2, which is a schematic structural diagram of a media-isolated pressure sensor according to a second embodiment of the present invention. In the second embodiment, the connecting portion 221 and the cover plate 222 form an inverted C-shaped configuration, and the connecting portion and the cover plate are integrally formed.
Further, referring to fig. 1, after the housing 20 is fastened on the substrate 10, the bottom of the housing 20 (i.e., the bottom of the sidewall 21) is hermetically connected to the surface of the substrate 10 by a material such as an adhesive or solder paste, so that the accommodating cavity 11 is a closed cavity.
The pressure sensor chip 30 is fixed on the substrate 10 and is disposed in the accommodating cavity 11. In this embodiment, one pressure sensor chip 30 is disposed on the surface of the substrate 10, and in other embodiments of the present invention, two or more pressure sensor chips 30 are disposed on the surface of the substrate 10. The pressure sensor chip 30 is electrically connected to the electrical connection lines of the substrate 10, thereby electrically connecting the pressure sensor chip 11 to an external structure. Further, a conductive pad (not shown in the drawings) is disposed at the bottom of the substrate 10, and is electrically connected to the electrical connection circuit of the substrate 10, and an external structure can be electrically connected to the conductive pad, so as to electrically connect the pressure sensor chip 30 to the external structure.
Further, in the present embodiment, the media-isolated pressure sensor further includes a functional chip, such as an ASIC chip 31, and the ASIC chip 31 is stacked on the pressure sensor chip 30 to realize a miniaturized package. The pressure sensor chip 30 and the ASIC chip 31 are electrically connected to the substrate 10 through metal wires. In other embodiments of the present invention, the functional chip may further include other chips for the media-isolated pressure sensor.
The medium liquid fills the accommodating cavity 11, and the external pressure can be conducted to the pressure sensor chip 30 through the housing 20 and the medium liquid. The medium liquid may be silicone oil.
Further, an oil filling hole 12 is arranged on the base plate 10, and the oil filling hole 12 is communicated with the accommodating cavity 11. The medium liquid is injected into the accommodating cavity 11 through the oil injection hole 12. And after the medium liquid is injected, filling a sealing material 13 into the oil filling hole 12 to seal the accommodating cavity 11 to form a sealed oil filling space. The sealing material may be solder paste or glue.
Further, the top cover 222 is made by a rubber vulcanization process, the thickness of the top cover 222 is less than 2 mm, and the smaller the media-isolated pressure sensor is, the smaller the thickness of the top cover 222 is. The thickness and rubber amount of the top cover 222 are smaller than those of a conventional flexible top cover, so that the process implementation difficulty is reduced, and the cost is reduced.
Further, the outer surface of the sidewall 21 has a groove 210, and the groove 210 is used for placing a sealing ring (not shown in the drawings) to perform a radial sealing function on the media-isolated pressure sensor.
For the housing 20, if the housing 20 is made of a metal material, welding is usually required, the generated welding stress causes a decrease in the output accuracy of the pressure sensor, and the metal film housing has a very small thickness and is easily damaged, which directly causes a loss of accuracy of the pressure sensor; if the housing 20 is made of a flexible material, the housing 20 is not as good in support as a metal material, and is difficult to seal, and is bonded by glue, so that the reliability is poor. The shell of the medium isolation type pressure sensor comprises the side wall made of hard materials and the top cover made of flexible materials, so that the measurement precision and the supporting force can be balanced, the reliability is considered, the output of the medium isolation type pressure sensor is ensured, the defects caused by a single shell material can be avoided, and the performance of the medium isolation type pressure sensor is greatly improved.
In addition, the medium isolation type pressure sensor can realize miniaturization, can be applied to consumer electronics and wearable products, greatly improves the application range of the medium isolation type pressure sensor, can be manufactured, calibrated and retested in batches in the calibration of the medium isolation type pressure sensor, greatly improves the production efficiency and reduces the production cost.
The utility model also provides a manufacturing method of the medium isolation type pressure sensor.
Fig. 3 is a schematic step diagram of a manufacturing method of a media-isolated pressure sensor according to a third embodiment of the present invention, referring to fig. 3, the manufacturing method of the media-isolated pressure sensor includes the following steps:
referring to step S30 and fig. 1, a substrate 10 and a housing 20 are provided, the housing 20 includes a sidewall 21 and a top cover 22, the sidewall 21 is hermetically connected to the top cover 22, the sidewall 21 is made of a hard material, and the top cover 22 is made of a flexible material.
The present invention also provides a method of forming the housing 20. The concrete description is as follows:
referring to fig. 4A, the sidewall 21 formed by hard material is provided. In this step, the side wall 21 may be formed by a preforming technique. Further, after the step, the step of cleaning the side wall is further included to remove impurities on the surface of the side wall 21 and improve the bonding force between the subsequent side wall 21 and the bonding layer 23. For example, in the present embodiment, the sidewall is made of a metal material, and after the sidewall 21 is formed, the sidewall 21 is sandblasted or cleaned by an organic cleaning agent to remove impurities such as grease on the metal surface.
Referring to fig. 4B, an adhesive layer 23 is formed on the inner side of the sidewall 21. In this step, the inner surface of the sidewall 21 may be subjected to a glue coating process, which may be a dipping process or a spraying process, followed by drying, and a glue coating layer, i.e., the adhesive layer 23, is formed on the surface of the sidewall 21. In this step, when the adhesive coating process is performed, the adhesive layers are formed on all the inner side surfaces of the side walls 21, and after this step, the excess adhesive layers are removed, and only the adhesive layer 23 corresponding to the region where the top cover 22 is to be formed remains.
Referring to fig. 4C, the sidewall 21 is disposed on a mold, a first gap is formed between the mold and a predetermined position of the sidewall 21, the mold has a transverse second gap, and the first gap is communicated with the second gap. Wherein, the preset position is a position where the side wall 21 needs to be connected with the top cover.
In this embodiment, the mold includes an upper mold 41 and a lower mold 42 which are disposed opposite to each other in the vertical direction, the first gap 401 is formed between the upper mold 41 and the sidewall 21, and the second gap 402 is formed between the upper mold 41 and the lower mold 42. In other embodiments of the present invention, the first gap 401 is formed between the lower mold 42 and the sidewall 21, and the second gap 402 is formed between the upper mold 41 and the lower mold 42.
Referring to fig. 4D, a flexible material is dropped along the gap and cured to form the top cover, wherein the side wall is connected to the top cover through the adhesive layer. In this embodiment, a fluid rubber is dropped into the first slit 401 and the second slit 402, and is subjected to a high temperature treatment to mold the rubber, thereby forming the integrated housing 20. The housing 20 has good air tightness and can prevent the medium liquid in the accommodating cavity from leaking.
In the embodiment, the top cover 22 is formed by a rubber vulcanization process, so that the scheme is easy to implement, the process implementation difficulty is low, the bonding effect is good, and good sealing can be realized. In addition, the rubber amount can be strictly controlled by adopting a glue dripping mode, and the consistency of products is ensured.
In the above-described embodiment of forming the housing 20, in other embodiments of the present invention, the side wall 21 and the top cover 22 may be formed in advance, and the side wall 21 and the top cover 22 may be bonded by the adhesive layer 23.
Referring to step S31 and fig. 1, at least one pressure sensor chip 30 is disposed on the surface of the substrate 10.
In this step, the pressure sensor chip 30 may be fixed on the substrate 10 using glue. In the present embodiment, the media-isolated pressure sensor further includes a functional chip, such as an ASIC chip 31, and the ASIC chip 31 is stacked on the pressure sensor chip 30 to realize a miniaturized package. The ASIC chip 31 is bonded to the surface of the pressure sensor chip 30 by glue. The pressure sensor chip 30 and the ASIC chip 31 are electrically connected to the substrate 10 by metal wires. The signals on the pressure sensor chip 30 and the ASIC chip 31 are transmitted through metal wires and transmitted to the substrate 10. The substrate 10 is provided with an electrical connection circuit, the bottom surface of the substrate 10 is provided with a conductive pad, and a metal wire is connected with the electrical connection circuit and transmits signals from the inside to the outside through the conductive pad to form a complete circuit transmission.
Further, in other embodiments of the present invention, the pressure sensor chip 30 and the ASIC chip 31 may be laid flat instead of being stacked.
Further, in other embodiments of the present invention, solder balls are disposed on the bottoms of the pressure sensor chip 30 and the ASIC chip 31 to replace the metal wires for electrical connection.
Referring to step S32 and fig. 1, the housing 20 is fastened to the substrate 10, the housing 10 and the substrate 10 form an accommodating cavity 11, and the pressure sensor chip 30 is disposed in the accommodating cavity 11. In this step, if the sidewall 21 is made of metal, a circle of solder ring is reserved on the substrate 10, and the substrate 10 and the sidewall 21 are soldered by SMT reflow; if the sidewall 21 is made of other materials, the sidewall 21 and the substrate 10 may be directly sealed and bonded by glue without providing the solder ring on the substrate 10.
Optionally, an oil hole 13 is provided on the base plate 10, the oil hole 13 is communicated with the accommodating cavity 11, in this embodiment, the step of fastening the housing 20 to the base plate 11 further includes the following steps:
referring to step S33 and fig. 1, a filling medium liquid is injected into the accommodating chamber 11 along the oil hole 13, and the oil hole 13 is sealed. The medium liquid fills the accommodating cavity 11, and the external pressure can be conducted to the pressure sensor chip 30 through the housing 20 and the medium liquid. The medium liquid may be silicone oil.
Alternatively, the oil filling hole 13 may be sealed by a solder paste hole-blocking method or a glue filling method. Alternatively, in an embodiment of the present invention, the oil hole 13 is sealed by steel balls. To simplify the manufacturing process.
The manufacturing method of the medium isolation type pressure sensor can form the medium isolation type pressure sensor with the composite shell, greatly simplifies the manufacturing process of the medium isolation type pressure sensor, reduces the manufacturing difficulty, can balance the measurement precision and the supporting force, gives consideration to the reliability, ensures the output of the medium isolation type pressure sensor, can avoid the defects caused by a single shell material, and greatly improves the performance of the medium isolation type pressure sensor.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
Claims (7)
1. A media isolated pressure sensor, comprising:
a substrate;
the shell comprises a side wall and a top cover, the side wall is hermetically connected with the top cover, the side wall is made of a hard material, the top cover is made of a flexible material, and the shell is buckled on the substrate to form an accommodating cavity;
the pressure sensor chip is fixed on the substrate and is arranged in the accommodating cavity;
and the medium liquid is filled in the accommodating cavity, and the external pressure can be conducted to the pressure sensor chip through the shell and the medium liquid.
2. The media-isolated pressure sensor of claim 1, wherein an end of the top cover is bonded to a side of the sidewall by an adhesive layer.
3. The media isolated pressure sensor of claim 2, wherein the top cap comprises a connecting portion disposed at an end of the top cap and extending in a direction parallel to the side wall, and a cover plate positioned between the connecting portions.
4. The media-isolated pressure sensor of claim 3, wherein the connection portion forms a female configuration or an inverted C-shaped configuration with the cover plate, and the connection portion is integrally formed with the cover plate.
5. The media isolated pressure sensor of claim 1, wherein the top cover is formed using a rubber vulcanization process and has a thickness of less than 2 millimeters.
6. The media-isolated pressure sensor of claim 1, wherein the base plate is provided with an oil filler hole, the oil filler hole is communicated with the accommodating cavity, and a sealing material is filled in the oil filler hole.
7. The media isolated pressure sensor of claim 1, wherein the outer surface of the sidewall has a groove for seating a sealing ring.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202121798659.8U CN215492215U (en) | 2021-08-03 | 2021-08-03 | Medium isolation type pressure sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202121798659.8U CN215492215U (en) | 2021-08-03 | 2021-08-03 | Medium isolation type pressure sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN215492215U true CN215492215U (en) | 2022-01-11 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202121798659.8U Active CN215492215U (en) | 2021-08-03 | 2021-08-03 | Medium isolation type pressure sensor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN215492215U (en) |
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2021
- 2021-08-03 CN CN202121798659.8U patent/CN215492215U/en active Active
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Address after: 215300 Building M1A, Building No. 6, 88 Qianjin East Road, Kunshan Development Zone, Suzhou City, Jiangsu Province, 2nd Floor Patentee after: Kunshan Lingke Sensing Technology Co.,Ltd. Address before: 2 / F, building m1a, building 6, 88 Qianjin East Road, Suzhou Development Zone, Jiangsu Province Patentee before: Kunshan Lingke Sensing Technology Co.,Ltd. |