A new type of high overload differential pressure sensor
By designing an equal oil circuit structure with open oblique holes and hard seals in the differential pressure sensor, the measurement error and chip damage caused by the existing differential pressure sensors due to the unequal oil circuits are solved, and higher stability is achieved and precision, and simplify the oil circuit structure.
Patent Information
- Application Number
- CN202010094383.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2020-02-15
- Publication Date
- 2024-12-31
- Estimated Expiration
- 2040-02-15
AI Technical Summary
The existing differential pressure sensors have different oil circuits at both ends, resulting in measurement errors and impacts on the single crystal silicon chip, causing sensor damage.
A high overload differential pressure sensor with open inclined holes, hard sealing of central overload diaphragm, and equal oil circuits was designed. The oil circuit sealing is ensured through argon arc welding and sintering technology, and the central overload diaphragm is used to transform under high overload pressure. Apply pressure evenly to ensure that the volumes of the oil passages at both ends are equal.
It improves the stability and accuracy of the sensor, reduces the temperature drift performance, protects the single crystal silicon differential pressure chip from high-voltage overload damage, and simplifies the oil circuit structure, reduces the oil charge, and improves the overall performance of the sensor.
Smart Images
Figure CN111157171B_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of measuring instruments, and specifically relates to a novel high overload differential pressure sensor, and in particular to a high overload differential pressure sensor with an inclined hole, a central overload diaphragm hard seal, and equal oil circuits. Background Art
[0002] Existing differential pressure sensors include capacitive and single crystal silicon types. Single crystal silicon differential pressure sensors have the problem of unequal oil circuit volumes at both ends. When pressure is applied to the positive pressure end or the negative pressure end, if the oil circuits at both ends are unequal, it is equivalent to applying positive or negative pressure to the single crystal silicon chip, causing sensor measurement errors and unsatisfactory sensor temperature compensation data. When a pressure far higher than the range is applied to the positive pressure end or the negative pressure end, if the oil circuits at both ends are unequal, the single crystal silicon chip will also be impacted, thereby damaging the sensor. Summary of the invention
[0003] The object of the present invention is to provide a high overload differential pressure sensor with an inclined hole, a central overload diaphragm hard seal and equal oil circuits in view of the deficiencies in the prior art.
[0004] The technical solution adopted by the present invention is:
[0005] A novel high overload differential pressure sensor comprises a chip base, a single crystal silicon differential pressure chip, a gold wire, an oil-filled tube at the positive pressure end, an oil-filled tube at the negative pressure end, a positive pressure base, a positive pressure isolation diaphragm, a negative pressure base, a negative pressure isolation diaphragm, a central overload diaphragm, pins and a fluororubber ring; the chip base is installed in a groove at the center of the top of the positive pressure base, the chip base is sintered, and a single crystal silicon differential pressure chip is glued inside, and the single crystal silicon differential pressure chip is connected to the pins on the chip base through the gold wire, so as to realize the power supply and communication of the chip base; the positive pressure isolation diaphragm is welded by argon arc welding on the positive pressure base, the negative pressure isolation diaphragm is welded by argon arc welding on the negative pressure base, and the chip base is sintered There are two oil-filling pipes, which are divided into a positive-pressure oil-filling pipe and a negative-pressure oil-filling pipe. Oil circuits are opened inside the positive-pressure base and the negative-pressure base. The central overload diaphragm is installed between the negative-pressure base and the positive-pressure base. The negative-pressure base and the positive-pressure base are extruded concentrically to form a hard seal between the central overload diaphragm and the positive-pressure base and the negative-pressure base. The oil circuits in the positive-pressure base and the negative-pressure base are divided into positive-pressure oil circuits and negative-pressure oil circuits, and the volumes of the positive-pressure oil circuits and the negative-pressure oil circuits are equal. The positive-pressure oil circuit cavity is filled with silicone oil through the positive-pressure oil-filling pipe, and the negative-pressure oil circuit cavity is filled with silicone oil through the negative-pressure oil-filling pipe. After the oil filling is completed, the positive-pressure oil-filling pipe and the negative-pressure oil-filling pipe are blocked and sealed by argon arc welding.
[0006] The chip base is sleeved with a fluorine rubber ring, which is installed in the groove at the center of the top of the positive pressure base. The chip base and the positive pressure base are argon arc welded at the external connection to ensure sealing.
[0007] A horizontal oil circuit A is opened inside the positive pressure base, and the positive pressure isolation diaphragm contacts the oil circuit A; a horizontal oil circuit D corresponding to the oil circuit A is opened inside the negative pressure base, and the negative pressure isolation diaphragm contacts the oil circuit D.
[0008] The two sides of the central overload diaphragm are respectively the oil circuit J of the positive pressure base and the oil circuit E of the negative pressure base.
[0009] The positive pressure base and the negative pressure base are argon arc welded at the external connection to ensure the sealing performance.
[0010] An oil circuit C is opened at the bottom of the chip base, and the oil circuit C is connected with the oil circuit A through the oil circuit B inside the positive pressure base. An oil circuit H is opened inside the chip base, and the single crystal silicon differential pressure chip separates the oil circuit C and the oil circuit H. The oil circuit C side is the positive pressure oil circuit, and the oil circuit H side is the negative pressure oil circuit; the chip base, the positive pressure base, and the negative pressure base together form an oil circuit G, and the oil circuit G is connected with the oil circuit H; an inclined hole is opened in the negative pressure base to form an oil circuit F, one end of the oil circuit F is connected with the oil circuit G, and the other end is connected with the oil circuit E.
[0011] The oil circuit of the positive pressure end oil filling pipe is connected with the oil circuit C through the gap between the chip base and the bottom of the positive pressure base, and the oil circuit of the negative pressure end oil filling pipe is connected with the oil circuit G.
[0012] The mechanical properties of the central overload diaphragm are adjusted through heat treatment.
[0013] When the rated pressure is applied to the positive pressure isolation diaphragm, the pressure pushes the silicone oil through oil circuit A, oil circuit B, and oil circuit C, acting on the positive pressure end of the single crystal silicon differential pressure chip, and the chip generates a positive pressure signal; when the rated pressure is applied to the negative pressure isolation diaphragm, the pressure pushes the silicone oil through oil circuit D, oil circuit E, oil circuit F, oil circuit G, and oil circuit H, acting on the negative pressure end of the single crystal silicon differential pressure chip, and the chip generates a negative pressure signal; a fluorine rubber ring is mounted on the chip base to separate the positive pressure oil circuit and the negative pressure oil circuit above and below the chip base.
[0014] When high overload pressure is applied to the positive pressure isolation diaphragm, the rated pressure pushes the silicone oil through oil circuit A, oil circuit B, and oil circuit C, and acts on the positive pressure end of the single crystal silicon differential pressure chip; the overload pressure acts on the central overload diaphragm through oil circuit A, oil circuit I, and oil circuit J, causing the central overload diaphragm to deform toward the negative pressure end, thereby pushing the silicone oil through oil circuit F, oil circuit G, and oil circuit H, and acting on the negative pressure end of the single crystal silicon differential pressure chip, so that the positive and negative pressure ends of the single crystal silicon differential pressure chip act simultaneously;
[0015] When high overload pressure is applied to the negative pressure isolation diaphragm, the rated pressure pushes the silicone oil through oil circuit D, oil circuit E, oil circuit F, oil circuit G, and oil circuit H, acting on the negative pressure end of the single crystal silicon differential pressure chip; the overload pressure acts on the central overload diaphragm through oil circuit D and oil circuit E, causing the central overload diaphragm to deform toward the positive pressure end, thereby pushing the silicone oil through oil circuit I, oil circuit B, and oil circuit C, acting on the positive pressure end of the single crystal silicon differential pressure chip, so that the positive and negative pressure ends of the single crystal silicon differential pressure chip act simultaneously.
[0016] The central overload diaphragm does not deform under rated pressure, but deforms under overload pressure after the rated pressure is exceeded.
[0017] Compared with the prior art, the present invention has the following beneficial effects:
[0018] (1) The present invention provides a novel high overload differential pressure sensor, wherein a fluorine rubber ring is sleeved on the chip base to separate the oil paths of the positive and negative pressure ends;
[0019] (2) The present invention provides a novel high overload differential pressure sensor, in which an oblique hole is opened on the negative pressure base, the oil circuit is simplified, the oil filling amount is reduced, the temperature drift performance is improved, and thus the stability of the sensor is improved;
[0020] (3) The present invention provides a novel high overload differential pressure sensor, in which the central overload diaphragm is extruded to achieve a hard sealing effect, remove stress, and improve the performance of the central overload diaphragm;
[0021] (4) The present invention provides a novel high overload differential pressure sensor to ensure that the volume of the oil circuit at the positive pressure end or the negative pressure end is equal. The accuracy of the single crystal silicon differential pressure chip requires equal oil circuits at both ends to ensure that the oil volume at the positive pressure end and the negative pressure end is equal. The equal oil circuits actually mean that the oil volume at the positive pressure end and the negative pressure end is equal. The volume of the single crystal silicon differential pressure chip and the oil circuit volume are precisely calculated through 3D modeling. The length of the oil circuit at both ends is adjusted to achieve equal oil volume. The equal oil volume acts on the positive and negative ends of the single crystal silicon differential pressure chip, thereby achieving stable accuracy of the single crystal silicon differential pressure chip. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 A schematic diagram of the structure of a novel high overload differential pressure sensor provided by the present invention;
[0023] In the figure: 1. chip base; 2. single crystal silicon differential pressure chip; 3. gold wire; 4. oil-filled tube at the positive pressure end; 5. oil-filled tube at the negative pressure end; 6. positive pressure base; 7. positive pressure isolation diaphragm; 8. negative pressure base; 9. negative pressure isolation diaphragm; 10. center overload diaphragm; 11. pin; 12. fluororubber ring. DETAILED DESCRIPTION
[0024] A novel high overload differential pressure sensor provided by the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.
[0025] like Figure 1 As shown, a novel high overload differential pressure sensor provided by the present invention comprises a chip base 1, a single crystal silicon differential pressure chip 2, a gold wire 3, a positive pressure end oil-filled tube 4, a negative pressure end oil-filled tube 5, a positive pressure base 6, a positive pressure isolation diaphragm 7, a negative pressure base 8, a negative pressure isolation diaphragm 9, a central overload diaphragm 10, a pin 11, and a fluorine rubber ring 12;
[0026] The chip base 1 is sintered, and a single crystal silicon differential pressure chip 2 is glued inside. The single crystal silicon differential pressure chip 2 is connected to the pin 11 on the chip base 1 through a gold wire 3, so as to realize the power supply and communication of the chip base 1;
[0027] A groove is provided at the center of the top of the positive pressure base 6, a fluorine rubber ring 12 is sleeved on the chip base 1, the chip base 1 is installed inside the groove, and the chip base 1 and the positive pressure base 6 are argon arc welded at welding II to ensure sealing;
[0028] A positive pressure isolation diaphragm 7 is welded by argon arc welding on the positive pressure base 6, and a negative pressure isolation diaphragm 9 is welded by argon arc welding on the negative pressure base 8. A horizontal oil circuit A is opened inside the positive pressure base 6, and the positive pressure isolation diaphragm 7 is in contact with the oil circuit A; a horizontal oil circuit D corresponding to the oil circuit A is opened inside the negative pressure base 8, and the negative pressure isolation diaphragm 9 is in contact with the oil circuit D;
[0029] An oil circuit J is opened on one side of the positive pressure base 6, and an oil circuit E is opened on one side of the negative pressure base 8. The central overload diaphragm 10 is installed between the oil circuit J and the oil circuit E. The negative pressure base 8 and the positive pressure base 6 are extruded concentrically to form a hard seal between the central overload diaphragm 10 and the positive pressure base 6 and the negative pressure base 8. The positive pressure base 6 and the negative pressure base 8 are argon arc welded at welding position I to ensure sealing;
[0030] An oil circuit C is opened at the bottom of the chip base 1, and the oil circuit C is connected with the oil circuit A through the oil circuit B inside the positive pressure base 6. An oil circuit H is opened inside the chip base 1, and the single crystal silicon differential pressure chip 2 separates the oil circuit C and the oil circuit H. The oil circuit C side is the positive pressure oil circuit, and the oil circuit H side is the negative pressure oil circuit; the chip base 1, the positive pressure base 6, and the negative pressure base 8 together form an oil circuit G, and the oil circuit G is connected with the oil circuit H; an inclined hole is opened in the negative pressure base 8 to form an oil circuit F, one end of the oil circuit F is connected with the oil circuit G, and the other end is connected with the oil circuit E; the main purpose of opening the inclined hole is to shorten the oil circuit and reduce the amount of oil. When measuring in field applications, high or low temperature conditions may be encountered in the measured medium. The less the amount of oil at the positive and negative ends, the smaller the change of the oil affected by temperature, and the lower the impact on the single crystal silicon differential pressure chip, thereby achieving stable accuracy of the single crystal silicon differential pressure chip.
[0031] Two oil-filled tubes are sintered on the chip base 1, which are divided into a positive pressure end oil-filled tube 4 and a negative pressure end oil-filled tube 5; the oil path of the positive pressure end oil-filled tube 4 is connected to the oil path C through the gap at the bottom of the chip base 1 and the positive pressure base 6, and the oil path of the negative pressure end oil-filled tube 5 is connected to the oil path G;
[0032] The mechanical properties of the central overload diaphragm 10 can be adjusted within a wide range through heat treatment. For example, in order to obtain high mechanical strength and fatigue resistance, the performance can be obtained by controlling phase change and precipitation hardening treatment. The treated central overload diaphragm can withstand 60,000 impacts without cracks or deformation.
[0033] The positive-pressure end oil path cavity is filled with silicone oil through the positive-pressure end oil filling pipe 4, and the negative-pressure end oil path cavity is filled with silicone oil through the negative-pressure end oil filling pipe 5. After the oil filling is completed, the positive-pressure end oil filling pipe 4 and the negative-pressure end oil filling pipe 5 are blocked and sealed by argon arc welding.
[0034] The connection of the chip base 1, the positive pressure end oil filling tube 4, the negative pressure end oil filling tube 5, and the pin 11 adopts metal-glass packaging technology. The metal shell makes the product durable, with high environmental adaptability and good sealing performance. The working temperature can reach -55-300℃, the insulation resistance ≥2000MΩ, the withstand voltage 1000V (50Hz), and the sealing ≤1*10 -9 Pa.cm 3 / S, pressure resistance 40MPa 1h.
[0035] The working principle of the present invention is:
[0036] When the rated pressure is applied to the positive pressure isolation diaphragm 7, the pressure pushes the silicone oil through the oil circuit A, oil circuit B, and oil circuit C, acting on the positive pressure end of the single crystal silicon differential pressure chip 2, and the chip generates a positive pressure signal; when the rated pressure is applied to the negative pressure isolation diaphragm 9, the pressure pushes the silicone oil through the oil circuit D, oil circuit E, oil circuit F, oil circuit G, and oil circuit H, acting on the negative pressure end of the single crystal silicon differential pressure chip 2, and the chip generates a negative pressure signal; at this time, because the chip base 1 is provided with a fluororubber ring 12, the positive pressure oil circuit and the negative pressure oil circuit can be separated above and below the chip base 1.
[0037] When high overload pressure is applied to the positive pressure isolation diaphragm 7, the rated pressure pushes the silicone oil through oil circuit A, oil circuit B, and oil circuit C, and acts on the positive pressure end of the single crystal silicon differential pressure chip 2; the overload pressure acts on the central overload diaphragm 10 through oil circuit A, oil circuit I, and oil circuit J, causing the central overload diaphragm 10 to deform toward the negative pressure end, thereby pushing the silicone oil through oil circuit F, oil circuit G, and oil circuit H, and acting on the negative pressure end of the single crystal silicon differential pressure chip 2, so that the positive and negative pressure ends of the single crystal silicon differential pressure chip 2 act simultaneously, achieving a static pressure effect, thereby protecting the single crystal silicon differential pressure chip 2 from damage by high-pressure overload.
[0038] When high overload pressure is applied to the negative pressure isolation diaphragm 9, the rated pressure pushes the silicone oil through oil circuit D, oil circuit E, oil circuit F, oil circuit G, and oil circuit H, and acts on the negative pressure end of the single crystal silicon differential pressure chip 2; the overload pressure acts on the central overload diaphragm 10 through oil circuit D and oil circuit E, causing the central overload diaphragm 10 to deform toward the positive pressure end, thereby pushing the silicone oil through oil circuit I, oil circuit B, and oil circuit C, and acting on the positive pressure end of the single crystal silicon differential pressure chip 2, so that the positive and negative pressure ends of the single crystal silicon differential pressure chip 2 act simultaneously, achieving a static pressure effect, thereby protecting the single crystal silicon differential pressure chip 2 from damage by high-pressure overload.
[0039] The central overload diaphragm will not deform under rated pressure. It will only deform when the rated pressure is exceeded and the overload pressure is reached.
[0040] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the art who, within the technical scope disclosed by the present invention, makes equivalent substitutions or changes based on the technical scheme and inventive concept of the present invention should be covered within the protection scope of the present invention.
Claims
1. A new type of high overload differential pressure sensor, characterized in that: The invention comprises a chip base (1), a single crystal silicon differential pressure chip (2), a gold wire (3), a positive pressure end oil filling pipe (4), a negative pressure end oil filling pipe (5), a positive pressure base (6), a positive pressure isolation diaphragm (7), a negative pressure base (8), a negative pressure isolation diaphragm (9), a central overload diaphragm (10), a pin (11), and a fluororubber ring (12); the chip base (1) is installed in a groove at the center position of the top of the positive pressure base (6); the chip base (1) is sintered, and a single crystal silicon differential pressure chip (2) is glued inside; the single crystal silicon differential pressure chip (2) is connected to the pin (11) on the chip base (1) through the gold wire (3), so as to realize the power supply and communication of the chip base (1); the positive pressure isolation diaphragm (7) is welded on the positive pressure base (6), the negative pressure isolation diaphragm (9) is welded on the negative pressure base (8), and the chip base (11) is welded on the positive pressure base (6). (1) Two oil-filled pipes are sintered on the upper side, which are divided into a positive pressure end oil-filled pipe (4) and a negative pressure end oil-filled pipe (5); oil paths are opened inside the positive pressure base (6) and the negative pressure base (8); the central overload diaphragm (10) is installed between the negative pressure base (8) and the positive pressure base (6); the negative pressure base (8) and the positive pressure base (6) are coaxially extruded to connect the central overload diaphragm (10) with the positive pressure base (6) and the negative pressure base (6). 8) forming a hard seal, dividing the oil circuits in the positive pressure base (6) and the negative pressure base (8) into a positive pressure oil circuit and a negative pressure oil circuit, wherein the volumes of the positive pressure oil circuit and the negative pressure oil circuit are equal; filling the positive pressure oil circuit cavity with silicone oil through the positive pressure end oil filling pipe (4), and filling the negative pressure oil circuit cavity with silicone oil through the negative pressure end oil filling pipe (5); after the oil filling is completed, the positive pressure end oil filling pipe (4) and the negative pressure end oil filling pipe (5) are blocked and sealed by argon arc welding; The chip base (1) is sleeved with the fluorine rubber ring (12) and installed in the groove at the center of the top of the positive pressure base (6). The chip base (1) and the positive pressure base (6) are argon arc welded at the external connection to ensure sealing; The positive pressure base (6) has a horizontal oil circuit A formed inside, and the positive pressure isolation diaphragm (7) is in contact with the oil circuit A; the negative pressure base (8) has a horizontal oil circuit D formed inside corresponding to the oil circuit A, and the negative pressure isolation diaphragm (9) is in contact with the oil circuit D; The two sides of the central overload diaphragm (10) are respectively the oil path J of the positive pressure base (6) and the oil path E of the negative pressure base (8); The chip base (1) has an oil circuit C at the bottom, and the oil circuit C is connected to the oil circuit A through the oil circuit B inside the positive pressure base (6). The chip base (1) has an oil circuit H inside, and the single crystal silicon differential pressure chip (2) separates the oil circuit C from the oil circuit H. The oil circuit C side is a positive pressure oil circuit, and the oil circuit H side is a negative pressure oil circuit. The chip base (1), the positive pressure base (6), and the negative pressure base (8) together form an oil circuit G inside, and the oil circuit G is connected to the oil circuit H. The negative pressure base (8) has an inclined hole inside to form an oil circuit F, and one end of the oil circuit F is connected to the oil circuit G, and the other end is connected to the oil circuit E. The oil circuit of the positive pressure end oil filling pipe (4) is connected to the oil circuit C through the gaps at the bottom of the chip base (1) and the positive pressure base (6), and the oil circuit of the negative pressure end oil filling pipe (5) is connected to the oil circuit G.
2. A novel high overload differential pressure sensor according to claim 1, characterized in that: The positive pressure base (6) and the negative pressure base (8) are argon arc welded at the external connection to ensure sealing.
3. A novel high overload differential pressure sensor according to claim 1, characterized in that: The mechanical properties of the central overload diaphragm (10) are adjusted through heat treatment.
4. A novel high overload differential pressure sensor according to any one of claims 1 to 3, characterized in that: When the rated pressure is applied to the positive pressure isolation diaphragm (7), the pressure pushes the silicone oil through oil circuit A, oil circuit B, and oil circuit C, acting on the positive pressure end of the single crystal silicon differential pressure chip (2), and the chip generates a positive pressure signal; when the rated pressure is applied to the negative pressure isolation diaphragm (9), the pressure pushes the silicone oil through oil circuit D, oil circuit E, oil circuit F, oil circuit G, and oil circuit H, acting on the negative pressure end of the single crystal silicon differential pressure chip (2), and the chip generates a negative pressure signal; a fluorine rubber ring (12) is sleeved on the chip base (1), separating the positive pressure oil circuit and the negative pressure oil circuit above and below the chip base (1).
5. A novel high overload differential pressure sensor according to any one of claims 1 to 3, characterized in that: When a high overload pressure is applied to the positive pressure isolation diaphragm (7), the rated pressure pushes the silicone oil through oil circuit A, oil circuit B, and oil circuit C to act on the positive pressure end of the single crystal silicon differential pressure chip (2); the overload pressure acts on the central overload diaphragm (10) through oil circuit A, oil circuit I, and oil circuit J, causing the central overload diaphragm (10) to deform toward the negative pressure end, thereby pushing the silicone oil through oil circuit F, oil circuit G, and oil circuit H to act on the negative pressure end of the single crystal silicon differential pressure chip (2), so that the positive and negative pressure ends of the single crystal silicon differential pressure chip (2) are simultaneously acted upon; When a high overload pressure is applied to the negative pressure isolation diaphragm (9), the rated pressure pushes the silicone oil through oil circuit D, oil circuit E, oil circuit F, oil circuit G, and oil circuit H, and acts on the negative pressure end of the single crystal silicon differential pressure chip (2); the overload pressure acts on the central overload diaphragm (10) through oil circuit D and oil circuit E, causing the central overload diaphragm (10) to deform toward the positive pressure end, thereby pushing the silicone oil through oil circuit I, oil circuit B, and oil circuit C, and acting on the positive pressure end of the single crystal silicon differential pressure chip (2), so that the positive and negative pressure ends of the single crystal silicon differential pressure chip (2) are simultaneously acted upon.
6. A novel high overload differential pressure sensor according to claim 5, characterized in that: The central overload diaphragm (10) does not deform under rated pressure, but deforms under overload pressure after the rated pressure is exceeded.