CN119165191A - A thermal flow velocity sensor and a method for preparing the same - Google Patents
A thermal flow velocity sensor and a method for preparing the same Download PDFInfo
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- CN119165191A CN119165191A CN202411217981.5A CN202411217981A CN119165191A CN 119165191 A CN119165191 A CN 119165191A CN 202411217981 A CN202411217981 A CN 202411217981A CN 119165191 A CN119165191 A CN 119165191A
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- 238000000034 method Methods 0.000 title claims description 19
- 238000010438 heat treatment Methods 0.000 claims abstract description 49
- 239000012530 fluid Substances 0.000 claims abstract description 39
- 230000008569 process Effects 0.000 claims description 12
- 239000011229 interlayer Substances 0.000 claims description 11
- 229910052581 Si3N4 Inorganic materials 0.000 claims description 9
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 claims description 9
- 239000000758 substrate Substances 0.000 claims description 9
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 6
- 238000009616 inductively coupled plasma Methods 0.000 claims description 6
- 238000004519 manufacturing process Methods 0.000 claims description 6
- 238000000059 patterning Methods 0.000 claims description 6
- 229910052710 silicon Inorganic materials 0.000 claims description 6
- 239000010703 silicon Substances 0.000 claims description 6
- 238000005530 etching Methods 0.000 claims description 3
- 238000004518 low pressure chemical vapour deposition Methods 0.000 claims description 3
- 238000001259 photo etching Methods 0.000 claims description 3
- 229920002120 photoresistant polymer Polymers 0.000 claims description 3
- 238000004528 spin coating Methods 0.000 claims description 3
- 230000004888 barrier function Effects 0.000 claims description 2
- 238000010030 laminating Methods 0.000 claims description 2
- 230000035945 sensitivity Effects 0.000 abstract description 9
- 238000002360 preparation method Methods 0.000 abstract description 6
- 230000000694 effects Effects 0.000 abstract description 5
- 230000000903 blocking effect Effects 0.000 abstract description 4
- 230000008859 change Effects 0.000 abstract description 4
- 230000009977 dual effect Effects 0.000 abstract description 2
- 238000005259 measurement Methods 0.000 abstract description 2
- 238000000926 separation method Methods 0.000 abstract 3
- 210000004081 cilia Anatomy 0.000 description 6
- 238000013461 design Methods 0.000 description 3
- 239000010410 layer Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 230000009471 action Effects 0.000 description 2
- 230000000875 corresponding effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000011144 upstream manufacturing Methods 0.000 description 2
- 230000006978 adaptation Effects 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000002596 correlated effect Effects 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 239000011664 nicotinic acid Substances 0.000 description 1
- 238000005192 partition Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P5/00—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft
- G01P5/10—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft by measuring thermal variables
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
- C23C16/22—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the deposition of inorganic material, other than metallic material
- C23C16/30—Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides
- C23C16/34—Nitrides
- C23C16/345—Silicon nitride
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
- C23C16/44—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating
- C23C16/52—Controlling or regulating the coating process
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P1/00—Details of instruments
- G01P1/006—Details of instruments used for thermal compensation
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Metallurgy (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- General Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Inorganic Chemistry (AREA)
- Aviation & Aerospace Engineering (AREA)
- Measuring Volume Flow (AREA)
Abstract
The invention discloses a thermal flow rate sensor and a preparation method thereof, wherein the thermal flow rate sensor comprises a sensing chip, a separation layer and a cover plate, the sensing chip comprises a chip body, a heating unit, a temperature sensing unit, a temperature compensation resistor and an ambient temperature resistor, a micro-fluid pipeline is formed between the separation layer and the chip body and between the separation layer and the cover plate and is communicated with the outside, the dual heating unit is combined with the micro-fluid pipeline, the blocking and viscous effects of the micro-fluid pipeline are utilized to convert the outside higher flow rate into the slow flow rate in the micro-fluid pipeline for measurement, the sensing range of the thermal flow rate sensor for flow rate signals of a flow field is greatly increased, on the other hand, the temperature sensing unit exposed in the outside flow field is utilized to form a bridge circuit with the temperature compensation resistor for measuring the flow rate under the condition of low flow rate of fluid, and the thermal flow rate sensor has very high sensitivity for flow rate change, and therefore, the thermal flow rate sensor has the great advantages of high sensitivity and wide range.
Description
Technical Field
The invention relates to the technical field of flow velocity sensors, in particular to a thermal flow velocity sensor and a preparation method thereof.
Background
The flow velocity sensor has great significance in the aspect of monitoring the surface flow field of the aircraft, and is one of hardware bases for realizing the functions of complex flow field identification, attitude control and the like of the aircraft. The performance of the flow rate sensor such as sensing accuracy, measuring range, sensitivity and other indexes directly influence the accuracy of the flow field sensing system of the aircraft.
The current flow rate sensors can be classified into thermal flow rate sensors and ciliated flow rate sensors according to the structure. Thermal flow rate sensors detect the magnitude of flow rate by measuring the amount of heat lost by a thermal element of the sensor due to the action of a fluid, and typically consist of a heating element, typically a heating resistor, for generating heat and placed in the fluid path and a temperature measuring element, including upstream and downstream temperature sensitive elements (e.g., thermistors or thermocouples) for measuring the temperature differential due to the flow of the fluid. When fluid flows through the heating resistor of the heat loss type sensor, heat on part of the heating resistor is taken away, so that the flow rate is calculated by measuring heat loss, or when the fluid passes through, the temperature difference between the upstream temperature measuring element and the downstream temperature measuring element is generated, and the temperature difference is larger along with the increase of the flow rate, and the flow rate is calculated by measuring the temperature difference. The bionic cilia structure based on the biological hair sensing principle is widely applied to the design of a flow rate sensor, the cilia structure deforms under the action of fluid-solid coupling, and the deformation of the cilia structure is converted into corresponding electric signals by using the sensing principles of piezoresistance, capacitance, piezoelectricity and the like so as to realize the sensing of the flow rate, therefore, the cilia type flow rate sensor generally comprises the cilia structure and a sensing element, the cilia structure is a unit for the interaction of the sensor and fluid, and is responsible for transmitting the fluid stimulus to a sensing layer, and the sensing element converts the corresponding fluid stimulus into the electric signals to be output.
In order to solve the problems, the invention provides the thermal flow velocity sensor and the preparation method thereof, and the design of the double heating units is combined with the micro-fluid structure, so that the range of the flow velocity sensor is greatly increased on the basis of ensuring high sensitivity, and the high-sensitivity and wide-range sensing of flow velocity information of a flow field is realized.
Disclosure of Invention
The invention aims to provide a thermal flow velocity sensor and a preparation method thereof, which achieve the purpose of improving the sensitivity and the perceptibility of flow velocity information of a flow field.
In order to achieve the above object, the present invention provides the following solutions:
The utility model provides a thermal type flow velocity sensor, includes sensing chip, interlayer and the apron that from bottom to top laminating set gradually, sensing chip includes the chip body, symmetry sets up first heating unit and the second heating unit of chip body left and right sides, from left to right symmetry sets up in proper order first temperature sensing unit and the second temperature sensing unit of first heating unit both sides, from left to right symmetry sets up the third temperature sensing unit and the fourth temperature sensing unit of second heating unit both sides, symmetry set up first temperature compensation resistance and second temperature compensation resistance of both sides and set up on the chip body around the chip body and set up ambient temperature resistance on the chip body, the interlayer with form micro-fluid pipeline and with external intercommunication between the apron, second temperature sensing unit and third temperature sensing unit all set up in the micro-fluid pipeline, first temperature sensing unit with fourth temperature sensing unit exposes in external flow field.
Preferably, the first temperature sensing unit, the second temperature sensing unit, the third temperature sensing unit, the fourth temperature sensing unit, the first heating unit, the second heating unit, the first temperature compensation resistor, the second temperature compensation resistor and the ambient temperature resistor are all connected with the leads on the chip body.
Preferably, the ambient temperature resistor comprises a first ambient temperature resistor and a second ambient temperature resistor which are symmetrically arranged at two sides of the first temperature compensation resistor or the second temperature compensation resistor.
Preferably, the interlayer comprises a circular middle plate and edge plates symmetrically arranged on two sides of the middle plate, the edge plates are arranged at intervals with the middle plate, a space between the edge plates and the middle plate forms a branch microfluidic pipeline, and the branch microfluidic pipeline is communicated with the microfluidic pipeline.
A method of manufacturing a thermal flow sensor using the thermal flow sensor of any one of claims 1 to 4, comprising the steps of:
Forming a low-stress silicon nitride film on a silicon wafer substrate by adopting a low-pressure chemical vapor deposition mode;
Patterning the silicon nitride film by adopting L ift-off process to form a first heating unit, a second heating unit, a first temperature sensing unit, a second temperature sensing unit, a third temperature sensing unit and a fourth temperature sensing unit;
Patterning to form an electrode by adopting an Li ft-off process;
etching the silicon nitride film by using the patterned photoresist as a mask ICP (inductively coupled plasma) dry method to form grooves among the first heating unit, the second heating unit, the first temperature sensing unit, the second temperature sensing unit, the third temperature sensing unit and the fourth temperature sensing unit;
forming an interlayer by spin-coating the photoetching SU-8 micro-fluid pipeline and the branch micro-fluid pipeline;
Dicing the wafer dividing device by a dicing saw;
Bonding the cover plate;
the silicon substrate is isotropically etched by a dry method to form a suspended structure to reduce heat conduction along the substrate.
Preferably, the first heating unit, the second heating unit, and the first temperature sensing unit, the second temperature sensing unit, the third temperature sensing unit, and the fourth temperature sensing unit using the L ift-off process are patterned.
Preferably, the electrode made of Au/Cr is patterned by L ift-off process.
Compared with the prior art, the invention has the following technical effects:
1. The invention adopts the first heating unit and the second heating unit which are heated in double and are combined with the micro-fluid pipeline, and utilizes the blocking and viscous effects of the micro-fluid pipeline to convert the external higher flow rate into the slow flow rate in the micro-fluid pipeline for measurement, thereby greatly increasing the sensing range of the thermal flow rate sensor for flow rate signals of a flow field, and on the other hand, under the condition of low flow rate of fluid, the first temperature sensing unit and the fourth temperature sensing unit which are exposed in the external flow field are utilized to form a bridge circuit with the temperature compensation resistor for measuring the flow rate, and the thermal flow rate sensor has high sensitivity for flow rate change, so the thermal flow rate sensor has the great advantages of high sensitivity and wide range.
Drawings
In order to more clearly illustrate the invention or the technical solutions of the prior art, the drawings that are necessary for the embodiments will be briefly described below, it being evident that the drawings in the following description are only some embodiments of the invention and that other drawings can be obtained from these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic diagram of the structure of the present invention;
FIG. 2 is an exploded view of the present invention;
FIG. 3 is a schematic diagram of the structure of a sensor chip of the present invention;
FIG. 4 is a schematic view of the structure of the present invention during operation;
FIG. 5 is a graph showing the relationship between the temperature difference between the first temperature sensing unit and the temperature compensating resistor and the water flow rate at a low flow rate according to the present invention;
FIG. 6 is a graph showing the relationship between the temperature difference of the first temperature sensing unit and the fourth temperature sensing unit and the water flow rate at a high flow rate according to the present invention;
FIG. 7 is a flow chart of a method of manufacturing a thermal flow sensor according to the present invention;
The thermal type flow rate sensor comprises a thermal type flow rate sensor 1, a cover plate 2, a partition layer 3, a sensing chip 4, a first heating unit 5, a second heating unit 6, a first temperature sensing unit 7, a second temperature sensing unit 8, a third temperature sensing unit 9, a fourth temperature sensing unit 10, a first environment temperature resistor 11, a second environment temperature resistor 12, a first temperature compensation resistor 13, a second temperature compensation resistor 14, a second temperature compensation resistor 15 and a lead.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
The invention aims to provide a thermal flow velocity sensor and a preparation method thereof, which achieve the purpose of improving the sensitivity and the perceptibility of flow velocity information of a flow field.
In order that the above-recited objects, features and advantages of the present invention will become more readily apparent, a more particular description of the invention will be rendered by reference to the appended drawings and appended detailed description.
Referring to fig. 1 to 6, the thermal flow rate sensor comprises a sensing chip, an interlayer and a cover plate, wherein the sensing chip, the interlayer and the cover plate are sequentially attached from bottom to top, the sensing chip comprises a chip body, a first heating unit and a second heating unit which are symmetrically arranged at the left side and the right side of the chip body, a first temperature sensing unit and a second temperature sensing unit which are sequentially and symmetrically arranged at the two sides of the first heating unit from left to right, a third temperature sensing unit and a fourth temperature sensing unit which are sequentially and symmetrically arranged at the two sides of the second heating unit from left to right, and a first temperature compensation resistor and a second temperature compensation resistor which are symmetrically arranged at the front side and the rear side of the chip body, and an ambient temperature resistor which is arranged on the chip body, a micro-fluid pipeline is formed between the interlayer and the chip body and the cover plate and is communicated with the outside, and the second temperature sensing unit and the third temperature sensing unit are respectively arranged in the micro-fluid pipeline, and the first temperature sensing unit and the fourth temperature sensing unit are respectively exposed in the micro-fluid pipeline.
Referring to fig. 4 to 5, the description of the sensing principle of the sensor is made with the water flow direction as the left-to-right direction. At low flow rate, the fluid flow takes away the heat of the first temperature sensing unit and the fourth temperature sensing unit exposed in the external field, and due to the blocking and viscous effects of the micro-fluid pipeline, the flow rate in the micro-fluid pipeline approaches zero, but the external flow rate can take away the heat of the second temperature sensing unit and the third temperature sensing unit in the micro-fluid pipeline through the diffusion of the cover plate, so that the temperatures of the second temperature sensing unit and the third temperature sensing unit are reduced, therefore, at low flow rate, the first temperature sensing unit directly exposed in the external field and positioned at the front end of the sensor is adopted as a flow rate sensing element, and a bridge circuit is formed by temperature compensation resistors to counteract the influence of the fluid environment temperature on the sensor and convert the resistance change into voltage signal output. It can be seen that the flow sensor has the characteristic of high sensitivity at low flow rates.
Referring to fig. 4 and 6, at a high flow rate, the fluid in the microfluidic channel flows, and the internal flow rate is positively correlated with the external flow rate, and the fluid flow in the microfluidic channel diffuses more heat of the second heating unit to the fourth temperature sensing unit and increases the temperature of the fourth temperature sensing unit, but the flow rate in the microfluidic channel is far less than the external flow rate due to the blocking and viscous effects of the microfluidic channel, which expands the sensing range of the fourth temperature sensing unit to the external flow rate. Therefore, at high flow rate, the temperature of the first temperature sensing unit continuously decreases and tends to the ambient temperature along with the increase of the flow rate, and the temperature of the fourth temperature sensing unit continuously increases, so that the influence of the ambient temperature of the fluid on the sensor is counteracted by the bridge circuit formed by the first temperature sensing unit and the fourth temperature sensing unit, and the resistance change is converted into a voltage signal to be output. It can be seen that the design and microfluidic structure of the dual heating units of the flow sensor greatly increases its sensing range of flow rate.
Referring to fig. 3, the first temperature sensing unit, the second temperature sensing unit, the third temperature sensing unit, the fourth temperature sensing unit, the first heating unit, the second heating unit, the first temperature compensation resistor, the second temperature compensation resistor and the ambient temperature resistor are all connected with the leads on the chip body.
Referring to fig. 3, the ambient temperature resistor includes a first ambient temperature resistor and a second ambient temperature resistor symmetrically disposed at both sides of the first temperature compensation resistor or the second temperature compensation resistor.
Referring to fig. 2, the barrier layer includes a circular middle plate and edge plates symmetrically disposed at both sides of the middle plate, the edge plates are disposed at intervals with the middle plate, a gap between the edge plates and the middle plate forms a branch microfluidic channel, and the branch microfluidic channel is communicated with the microfluidic channel.
A method of manufacturing a thermal flow sensor comprising the steps of:
Forming a low-stress silicon nitride film on a silicon wafer substrate by adopting a low-pressure chemical vapor deposition mode;
Patterning the silicon nitride film by adopting L ift-off process to form a first heating unit, a second heating unit, a first temperature sensing unit, a second temperature sensing unit, a third temperature sensing unit and a fourth temperature sensing unit;
Patterning to form an electrode by adopting an Li ft-off process;
etching the silicon nitride film by using the patterned photoresist as a mask ICP (inductively coupled plasma) dry method to form grooves among the first heating unit, the second heating unit, the first temperature sensing unit, the second temperature sensing unit, the third temperature sensing unit and the fourth temperature sensing unit;
forming an interlayer by spin-coating the photoetching SU-8 micro-fluid pipeline and the branch micro-fluid pipeline;
Dicing the wafer dividing device by a dicing saw;
Bonding the cover plate;
the silicon substrate is isotropically etched by a dry method to form a suspended structure to reduce heat conduction along the substrate.
Further, a L ift-off process is adopted to pattern and form a first heating unit, a second heating unit, a first temperature sensing unit, a second temperature sensing unit, a third temperature sensing unit and a fourth temperature sensing unit which are made of Pt/Cr.
Further, an electrode made of Au/Cr is patterned by adopting L ift-off process.
The adaptation to the actual need is within the scope of the invention.
It should be noted that it will be apparent to those skilled in the art that the present invention is not limited to the details of the above-described exemplary embodiments, but may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.
Claims (7)
1. The utility model provides a thermal type flow velocity sensor, its characterized in that includes sensing chip, interlayer and the apron that from bottom to top laminating set gradually, sensing chip includes the chip body, symmetry set up first heating element and the second heating element of chip body left and right sides, from left to right symmetry set up in proper order first temperature sensing element and the second temperature sensing element of first heating element both sides, from left to right symmetry set up the third temperature sensing element and the fourth temperature sensing element of second heating element both sides in proper order, symmetry set up first temperature compensation resistance and second temperature compensation resistance of both sides and set up on the chip body around the chip body and set up ambient temperature resistance on the chip body, the interlayer with form the micro-fluid pipeline and with external intercommunication between the apron, second temperature sensing element and third temperature sensing element all set up in the micro-fluid pipeline, first temperature sensing element and fourth temperature sensing element expose in external flow field.
2. The thermal flow rate sensor of claim 1, wherein the first temperature sensing unit, the second temperature sensing unit, the third temperature sensing unit, the fourth temperature sensing unit, the first heating unit, the second heating unit, the first temperature compensation resistor, the second temperature compensation resistor, and the ambient temperature resistor are connected to leads on the chip body.
3. A thermal flow rate sensor according to claim 2, wherein the ambient temperature resistor comprises a first ambient temperature resistor and a second ambient temperature resistor symmetrically disposed on either side of the first temperature compensation resistor or the second temperature compensation resistor.
4. A thermal flow rate sensor according to claim 3, wherein the barrier comprises a circular middle plate and edge plates symmetrically disposed on both sides of the middle plate, the edge plates being spaced from the middle plate, the spacing between the edge plates and the middle plate forming a bypass microfluidic channel, the bypass microfluidic channel being in communication with the microfluidic channel.
5. A method of manufacturing a thermal flow sensor, characterized in that the thermal flow sensor according to any one of claims 1 to 4 is applied, comprising the steps of:
Forming a low-stress silicon nitride film on a silicon wafer substrate by adopting a low-pressure chemical vapor deposition mode;
patterning the silicon nitride film by using a Lift-off process to form a first heating unit, a second heating unit, a first temperature sensing unit, a second temperature sensing unit, a third temperature sensing unit and a fourth temperature sensing unit;
Patterning to form an electrode by using a Lift-off process;
etching the silicon nitride film by using the patterned photoresist as a mask ICP (inductively coupled plasma) dry method to form grooves among the first heating unit, the second heating unit, the first temperature sensing unit, the second temperature sensing unit, the third temperature sensing unit and the fourth temperature sensing unit;
forming an interlayer by spin-coating the photoetching SU-8 micro-fluid pipeline and the branch micro-fluid pipeline;
Dicing the wafer dividing device by a dicing saw;
Bonding the cover plate;
the silicon substrate is isotropically etched by a dry method to form a suspended structure to reduce heat conduction along the substrate.
6. The method of manufacturing a thermal flow rate sensor according to claim 5, wherein the first heating unit, the second heating unit, the first temperature sensing unit, the second temperature sensing unit, the third temperature sensing unit, and the fourth temperature sensing unit are patterned by using a Lift-off process.
7. The method of manufacturing a thermal flow rate sensor according to claim 6, wherein electrodes made of Au/Cr are patterned by a Lift-off process.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202411217981.5A CN119165191A (en) | 2024-09-02 | 2024-09-02 | A thermal flow velocity sensor and a method for preparing the same |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202411217981.5A CN119165191A (en) | 2024-09-02 | 2024-09-02 | A thermal flow velocity sensor and a method for preparing the same |
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| Publication Number | Publication Date |
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| CN119165191A true CN119165191A (en) | 2024-12-20 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202411217981.5A Pending CN119165191A (en) | 2024-09-02 | 2024-09-02 | A thermal flow velocity sensor and a method for preparing the same |
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- 2024-09-02 CN CN202411217981.5A patent/CN119165191A/en active Pending
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