Micro-channel packaged thermal differential pressure and flow velocity fusion sensing array and manufacturing method thereof

Abstract

The invention discloses a micro-channel packaged thermal differential pressure and flow velocity fusion sensing array and a manufacturing method thereof, and relates to the field of sensors, the array comprises a device layer, and the device layer is provided with a plurality of flow velocity sensors and a plurality of differential pressure sensors; the upper end and the lower end, located at the differential pressure sensors, of the device layer are each provided with a pipeline layer in an overlapped mode, the pipeline layers are provided with pipelines with the same number as the differential pressure sensors, and the differential pressure sensors are located in the corresponding pipelines; a substrate layer is stacked at the bottom of the pipeline layer at the lower part of the device layer and covers the device layer; a packaging layer is stacked on the top of the pipeline layer on the upper portion of the device layer, the packaging layer covers a pipeline of the pipeline layer, pressure measuring holes are formed in the positions, corresponding to the two ends of the pipeline, of the packaging layer, and the pressure measuring holes are communicated with the interior of the pipeline. The micro-channel packaged thermal differential pressure and flow velocity fusion sensing array manufactured based on the method integrates a plurality of differential pressure sensors and a plurality of flow velocity sensors, and can be attached to the surface of the leading edge of a wing to monitor the flow velocity and differential pressure information of the wing surface.

Description

Technical Field

[0001] The present invention relates to the field of sensor technology, and in particular to a microchannel packaged thermal pressure difference and flow velocity fusion sensor array and a manufacturing method thereof. Background Art

[0002] Differential pressure sensors and flow rate sensors are widely used in medical equipment, aerospace, and environmental monitoring systems. Conventional differential pressure sensors and flow rate sensors rely on the deformation of thin films or cantilever beams to convert capacitance, strain and other signals into electrical signal outputs.

[0003] In the field of aerospace, the airspeed and angle of attack of drones are calculated by monitoring the flow field of drone wings. Single flow field data, such as the velocity or pressure of the wing, is difficult to fully display the true state of the wing flow field, while multi-point distributed monitoring of pressure difference / flow velocity is more conducive to fully displaying the wing flow field. Existing multi-modal sensor array skins are all made by attaching multiple types of sensors (hard sensors and flexible sensors) to a flexible skin base.

[0004] The above method has the problems of difficulty in connecting the hard sensing unit to the flexible skin substrate circuit and difficulty in packaging, and the overall size is too thick and seriously interferes with the aerodynamic shape; MEMS sensor is a sensor manufactured using micro-electromechanical system (MEMS) technology. Flexible MEMS sensors rely on the sensing mechanism of film or cantilever deformation. When the flexible sensing unit is attached to the substrate, the movable sensitive element is easily damaged; sensors with flexible movable sensitive elements have a short lifespan, poor stability and consistency; therefore, it is urgent to design a device without a movable sensing unit and integrating multiple differential pressure sensors and multiple flow rate sensors, which can be attached to the leading edge surface of the wing to monitor the flow velocity and pressure difference information on the wing surface. Summary of the invention

[0005] The purpose of the present invention is to provide a microfluidic packaged thermal pressure difference and flow rate fusion sensor array and its manufacturing method to solve the problems existing in the above-mentioned prior art. It integrates multiple pressure difference sensors and multiple flow rate sensors and can be attached to the leading edge surface of the wing to monitor the flow velocity and pressure difference information on the wing surface.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] The present invention provides a microchannel packaged thermal pressure difference and flow rate fusion sensor array, comprising:

[0008] a device layer, on which a plurality of flow velocity sensors and a plurality of differential pressure sensors are arranged;

[0009] A pipeline layer, wherein the upper and lower ends of the device layer located at the position of the differential pressure sensor are respectively stacked with one pipeline layer, the pipeline layer is provided with the same number of pipelines as the differential pressure sensors, and the differential pressure sensors are located in the corresponding pipelines;

[0010] A base layer, the base layer is stacked at the bottom of the pipeline layer below the device layer, and the base layer covers the device layer;

[0011] The packaging layer is stacked on top of the pipeline layer above the device layer, the packaging layer covers the pipeline of the pipeline layer, and the packaging layer is provided with pressure measuring holes at positions corresponding to both ends of the pipeline, and the pressure measuring holes are connected to the inside of the pipeline.

[0012] Optionally, the pipeline layer includes an upper pipeline layer and a lower pipeline layer, the upper pipeline layer is located at the upper end of the position of the differential pressure sensor, and covers a plurality of the differential pressure sensors, the lower pipeline layer is located at the lower end of the position of the differential pressure sensor, and the differential pressure sensor is located in a pipeline opened between the upper pipeline layer and the lower pipeline layer; the lower pipeline layer is provided with an extension portion, the extension portion extends to cover the position of the flow velocity sensor, the extension portion is provided with square through holes having the same number as the flow velocity sensors, and each of the square through holes is correspondingly provided with a flow velocity sensor.

[0013] Optionally, each of the flow velocity sensors is provided with a heating unit, four temperature measuring units and a temperature compensation unit, the four temperature measuring units are symmetrically arranged around the heating unit, and grooves are arranged between the heating unit and the temperature measuring unit of the flow velocity sensor; the base layer, the grooves and the square through holes form an air flow channel of the flow velocity sensor, and the air flow channel is a microchannel structure.

[0014] Optionally, each of the differential pressure sensors is provided with a heating unit, two temperature measuring units and a temperature compensation unit; the temperature measuring units are symmetrically arranged at both ends of the heating unit, a groove is arranged between the heating unit and the temperature measuring unit of the differential pressure sensor, and the outer contour of the groove is consistent with the shape of the pipeline at the lower pipeline layer; the base layer, the pipeline of the lower pipeline layer, the groove, the pipeline of the upper pipeline layer and the pressure measuring hole of the packaging layer form the airflow channel of the differential pressure sensor, and the airflow channel is a microchannel structure.

[0015] Optionally, the temperature measuring unit is connected to a temperature measuring transmission electrode, and the heating unit is connected to a heating transmission electrode. The temperature measuring transmission electrode and the heating transmission electrode are both sheet-shaped structures. The temperature measuring transmission electrode and the heating transmission electrode are located on the same plane. The current input end and the current output end of the temperature measuring transmission electrode and the heating transmission electrode are both connected to welding pads, and several of the welding pads are arranged in parallel at one edge of the device layer.

[0016] Optionally, the temperature compensation unit includes a temperature compensation resistor disposed on the device layer, and the temperature compensation resistor is electrically connected to the heating transmission electrode.

[0017] Optionally, the temperature compensation resistor is located in the middle of the device layer and is covered by the upper pipeline layer and the lower pipeline layer.

[0018] Optionally, the heating unit uses a circular platinum resistor as a heating element; and the temperature measuring unit uses a serpentine platinum resistor as a calorimetric element.

[0019] Optionally, the heating unit and the temperature measuring unit both use serpentine platinum resistors.

[0020] Optionally, the airflow channel includes a reduced diameter pipe structure, the reduction ratio of which is between 0.3 and 0.7, and the heating unit and the temperature measuring unit of the differential pressure sensor are both located at the reduced diameter pipe structure of the airflow channel.

[0021] Optionally, the substrate layer, the pipeline layer, the device layer and the packaging layer are all made of polyimide.

[0022] The present invention also provides a method for manufacturing a microchannel packaged thermal pressure difference and flow rate fusion sensor array, comprising the following steps:

[0023] S1, spin-coat the first layer of PI on the silicon wafer and solidify it; PI (Polyimide), that is, polyimide, is a high-performance thermoplastic or thermosetting polymer, known for its excellent thermal stability, chemical stability and mechanical properties. PI materials are widely used in many fields such as electronics, aerospace, automobiles, microelectronics and semiconductor manufacturing.

[0024] S2, spin-coat photoresist on the first layer of PI and photoetch out electrode windows, then sputter Au / Cr layer as the electrodes of the heating module and the temperature measurement module; Au / Cr layer (Gold / Chromium Layer) refers to a double-layer structure consisting of a layer of chromium (Cr) and a layer of gold (Au), which is commonly used in microelectronics, semiconductor manufacturing, optical devices and other fields.

[0025] S3, placing the silicon wafer into NMP solution and heating it for degumming treatment; NMP solution, whose Chinese name is N-methylpyrrolidone, is a colorless and transparent organic solvent that is very common in chemical and industrial applications.

[0026] S4, spin-coat photoresist on the Au / Cr layer and the first layer of PI and photolithograph the temperature measurement window and the heating window, and then sputter Pt / Ti; the Pt / Ti layer (Platinum / Titanium Layer) refers to a double-layer structure consisting of a layer of titanium (Ti) and a layer of platinum (Pt), which is commonly used in microelectronics, semiconductor manufacturing, catalysis and surface coating and other fields.

[0027] S5, placing the silicon wafer in an NMP solution and heating it for degumming treatment;

[0028] S6, spin coating a second PI layer on the Au / Cr layer, the first PI layer and the Pt / Ti layer, and curing;

[0029] S7, spin-coat photoresist on the second layer of PI and photolithograph the groove window, then RIE etch the second layer of PI to the surface of the silicon wafer to form a groove structure; RIE etching (Reactive Ion Etching) is a dry etching technology used in the process of microelectronics and semiconductor manufacturing. RIE etching uses chemical reactions and physical bombardment in plasma to accurately remove materials, and is one of the important means of manufacturing microstructures.

[0030] S8, thermally pressing and bonding the upper pipeline layer and the device layer, and coating the upper pipeline layer with a layer of perfluoroethylene-propylene copolymer;

[0031] S9, hot-pressing and bonding the upper pipeline layer to the top of the encapsulation layer, and coating the encapsulation layer with a layer of perfluoroethylene-propylene copolymer;

[0032] S10, peeling the device layer off the silicon wafer;

[0033] S11, hot-pressing and bonding the lower pipeline layer to the bottom of the device layer, and coating the lower pipeline layer with a layer of perfluoroethylene-propylene copolymer;

[0034] S12, hot-pressing and bonding the lower pipe layer to the base layer, and coating the base layer with a layer of perfluoroethylene-propylene copolymer.

[0035] Compared with the prior art, the present invention has achieved the following technical effects:

[0036] Existing multi-modal sensor array skins are all made by attaching various types of sensors (including hard sensors and flexible sensors) to the skin base, which has the problems of difficulty in connecting the hard sensor unit to the flexible skin base circuit and difficulty in packaging; flexible MEMS sensors rely on the sensing mechanism of film or cantilever beam deformation, and the flexible sensor unit is easily damaged when attached to the base; sensors with flexible movable sensitive elements have a short lifespan, poor stability and consistency. The present invention realizes the integrated manufacturing of thermal pressure difference / flow velocity sensor arrays through the arrangement of thermal sensor arrays and multi-layer PI microchannel bonding. The skin with thermal sensors as the main body made by this method has the advantages of being softer, thinner and more stable, and has no movable sensitive elements. Its lifespan, stability and consistency are much higher than the sensor array using the sensing principle of movable sensitive elements.

[0037] In addition, the present invention uses microchannel bonding, and the heating unit and the temperature measuring unit are both thermosensitive elements. The thermosensitive elements are suspended in an array, which greatly improves the sensitivity of the thermal differential pressure sensor and the thermal flow velocity sensor. The flow velocity in the pipeline shows a characteristic of gradually decreasing from the center to the pipe wall. Through spatial structure design, the thermosensitive element is placed in the center of the pipeline. The sensitivity and resolution of the flexible thermal differential pressure sensor developed far exceed most of the currently reported differential pressure sensors. Due to the characteristics of full flexibility and non-movable sensing units, the sensor array made by the present invention has the advantages of bendable attachment, low cost, and not easy to break. It can be attached to the leading edge surface of the wing to monitor the flow field information such as wing surface flow velocity and pressure difference, and has broad application prospects for distributed atmospheric parameter systems for unmanned aerial vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention 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 present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 It is a schematic diagram of the structure of the thermal pressure difference and flow velocity fusion sensor array packaged in the microfluidic channel of the present invention;

[0040] Figure 2 It is a schematic diagram of the device layer of the present invention;

[0041] Figure 3 This is a schematic diagram of the upper pipeline layer of the present invention;

[0042] Figure 4 This is a schematic diagram of the lower pipeline layer of the present invention;

[0043] Figure 5 It is a schematic diagram of the encapsulation layer of the present invention;

[0044] Figure 6 is a schematic diagram of the base layer of the present invention;

[0045] Figure 7 It is a schematic diagram of the arrangement of the flow velocity sensor of the present invention;

[0046] Figure 8 It is a schematic diagram of the layout of the differential pressure sensor of the present invention;

[0047] Fig. 9 It is a schematic diagram of the working principle of the flow velocity sensor of the present invention;

[0048] Fig.10 This is a schematic diagram of the working principle of the differential pressure sensor of the present invention;

[0049] Fig.11 The present invention is a schematic flow chart of the method for manufacturing a thermal pressure difference and flow velocity fusion sensor array of microfluidic package.

[0050] In the figure: 1-base layer, 2-lower pipeline layer, 3-device layer, 4-upper pipeline layer, 5-packaging layer, 501-pressure measuring hole, 6-pipeline, 7-square through hole, 8-groove, 9-flow rate sensor, 10-differential pressure sensor, 11-temperature measuring unit, 12-heating unit, 13-temperature compensation unit, 14-temperature measuring transmission electrode, 15-heating transmission electrode. DETAILED DESCRIPTION

[0051] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] The purpose of the present invention is to provide a microfluidic packaged thermal pressure difference and flow rate fusion sensor array and its manufacturing method to solve the problems existing in the above-mentioned prior art. It integrates multiple pressure difference sensors and multiple flow rate sensors and can be attached to the leading edge surface of the wing to monitor the flow velocity and pressure difference information on the wing surface.

[0053] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0054] refer to Figures 1 to 8As shown, the present invention provides a microchannel packaged thermal differential pressure and flow velocity fusion sensor array, including a base layer 1, a lower pipeline layer 2, a device layer 3, an upper pipeline layer 4 and a packaging layer 5 stacked in sequence from bottom to top, and the base layer 1, the lower pipeline layer 2, the device layer 3, the upper pipeline layer 4 and the packaging layer 5 are all made of polyimide material. A plurality of flow velocity sensors 9 and a plurality of differential pressure sensors 10 are arranged on the device layer 3, and both the flow velocity sensors 9 and the differential pressure sensors 10 are thermal sensor structures; symmetrical pipeline grooves are provided at the bottom wall of the upper pipeline layer 4 and the top wall of the lower pipeline layer 2, and the pipeline grooves of the upper pipeline layer 4 and the corresponding pipeline grooves of the lower pipeline layer 2 are combined to form a complete pipeline 6, and pipelines 6 with the same number as the differential pressure sensors 10 are provided between the upper pipeline layer 4 and the lower pipeline layer 2, and a differential pressure sensor 10 is correspondingly provided in each pipeline 6, and the differential pressure sensor 10 does not overlap with the pipeline 6. The inner wall is in contact; the base layer 1 covers the device layer 3; the packaging layer 5 covers the position of the pipeline 6 of the pipeline layer, that is, the structure of the packaging layer 5 is the same as that of the upper pipeline layer 4, and the packaging layer 5 is provided with pressure measuring holes 501 at the positions corresponding to the two ends of the pipeline, and the pressure measuring holes 501 are connected to the inside of the pipeline 6, that is, each pipeline 6 is respectively connected to a pressure measuring hole 501 at both ends, and the gas can enter the corresponding pipeline 6 from a pressure measuring hole 501, and then flow through the pipeline 6 and flow out from the pressure measuring hole 501 at the other end of the pipeline 6. During this period, the differential pressure sensor 10 in the pipeline 6 realizes the pressure measurement function.

[0055] Further preferably, in order to avoid the pipeline layer from shielding the flow velocity sensor 9, in this embodiment, the upper pipeline layer 4 only covers the positions of multiple differential pressure sensors 10, and is missing at the position of the flow velocity sensor 9, and will not cover the position of the flow velocity sensor 9, and the lower pipeline layer 2 is integrally formed with an extension portion, and the extension portion extends to the position covering the flow velocity sensor 9. The extension portion can cover the position of the flow velocity sensor 9, but in this embodiment, the extension portion is provided with square through holes 7 with the same number as the flow velocity sensor 9, and each square through hole 7 is correspondingly provided with a flow velocity sensor 9. The square through hole 7 makes the extension portion not hinder the operation of the flow velocity sensor 9. Similarly, the structure of the packaging layer 5 is the same as that of the upper pipeline layer 4, and it does not have an extension portion, so it will not cover the flow velocity sensor 9.

[0056] In the present embodiment, each flow velocity sensor 9 is provided with a heating unit 12, four temperature measuring units 11 and a temperature compensation unit 13. The four temperature measuring units 11 are symmetrically arranged around the heating unit 12, and a groove 8 is arranged between the heating unit 12 and the temperature measuring unit 11 of the flow velocity sensor 9. The purpose of setting the groove 8 is to separate the heating unit 12 and the temperature measuring unit 11 so that there is no contact between the heating unit 12 and the temperature measuring unit 11; the base layer 1, the groove 8 and the square through hole 7 form the air flow channel of the flow velocity sensor 9, and the heating unit 12 and the temperature measuring unit 11 are arranged in the air and have no contact with the base layer 1, the groove 8 and the square through hole 7. The temperature measuring unit 11 is connected to a temperature measuring transmission electrode 14, and the heating unit 12 is connected to a heating transmission electrode 15. Both the temperature measuring transmission electrode 14 and the heating transmission electrode 15 are sheet-shaped structures. The temperature measuring transmission electrode 14 and the heating transmission electrode 15 are located on the same plane. The current input end and the current output end of the temperature measuring transmission electrode 14 and the heating transmission electrode 15 are connected to pads, and several pads are arranged in parallel at one side edge of the device layer 3.

[0057] like Fig. 9 As shown, the flow velocity sensor 9 of this embodiment uses a circular platinum resistor as the heating element of the heating unit 12; a serpentine platinum resistor as the calorimetric element of the temperature measuring unit 11; the heating element is heated by a constant temperature difference heating circuit, which is a circuit structure in the prior art, so it is not described in detail. When the airflow flows through the heating element and the calorimetric element, the temperature upstream of the heating element decreases, and the resistance of the calorimetric element at the upstream decreases; and the temperature downstream of the heating element increases, and the resistance of the calorimetric element at the downstream increases. By introducing the voltage signal into the operational amplifier through the Wheatstone bridge, the relationship between the voltage and the airflow velocity can be obtained. The Wheatstone bridge is a prior art, so it is not described in detail.

[0058] In this embodiment, each differential pressure sensor 10 is provided with a heating unit 12, two temperature measuring units 11 and a temperature compensation unit 13; the temperature measuring units 11 are symmetrically arranged at both ends of the heating unit 12, and a groove 8 is arranged between the heating unit 12 and the temperature measuring unit 11 of the differential pressure sensor 10, and the outer contour of the groove 8 is consistent with the shape of the pipeline at the lower pipeline layer 2; the pipeline grooves of the base layer 1, the lower pipeline layer 2, the grooves 8, the pipeline grooves of the upper pipeline layer 4 and the pressure measuring holes 501 of the packaging layer 5 form the airflow channel of the differential pressure sensor 10, and the airflow channel includes a reduced diameter pipeline structure, and its reduction ratio is between 0.3 and 0.7. The heating unit 12 and the temperature measuring unit 11 of the differential pressure sensor are both located at the reduced diameter pipeline structure position of the airflow channel, and the temperature measuring unit 11 and the heating unit 12 are suspended and are not in contact with the pipeline grooves, the grooves 8, the packaging layer 5, and the base layer 1. The temperature measuring unit 11 is connected to a temperature measuring transmission electrode 14, and the heating unit 12 is connected to a heating transmission electrode 15. Both the temperature measuring transmission electrode 14 and the heating transmission electrode 15 are sheet-shaped structures. The temperature measuring transmission electrode 14 and the heating transmission electrode 15 are located on the same plane. The current input end and the current output end of the temperature measuring transmission electrode 14 and the heating transmission electrode 15 are connected to pads, and several pads are arranged in parallel at one side edge of the device layer 3.

[0059] like Fig.10 As shown, the differential pressure sensor 10, the heating unit 12 and the temperature measuring unit 11 of this embodiment are all thermistors, and the thermistors are encapsulated in the pipeline to achieve differential pressure measurement. The small serpentine platinum resistor is used as the thermistor; the large serpentine platinum resistor is used as the temperature compensation resistor; the thermistor is heated by a constant temperature difference heating circuit, and the pressure is introduced by the pressure measuring hole 501 at one end of the pipeline and exported by the pressure measuring hole 501 at the other end of the pipeline. The pipeline forms airflows of different flow rates due to the pressure difference. The thermistor is heated by a constant temperature difference heating circuit. When the airflow flows through the thermistor, the temperature of the heating element decreases and the resistance decreases, the balance of the Wheatstone bridge is destroyed, and the output voltage of the bridge increases, so as to achieve the purpose of heating the thermistor and rebalancing the Wheatstone bridge. The relationship between the output voltage of the bridge and the pressure difference can be obtained, thereby obtaining the pressure difference on both sides of the pipeline.

[0060] The temperature compensation unit 13 includes a temperature compensation resistor disposed on the device layer 3, the temperature compensation resistor is electrically connected to the heating transmission electrode 15, the temperature compensation resistor is located in the middle of the device layer 3, and is covered by the upper pipeline layer 4 and the lower pipeline layer 2. The temperature compensation resistor is mainly to reduce the influence of the external environment temperature, and the temperature compensation resistor is coiled in a serpentine shape.

[0061] The present invention also provides a method for manufacturing a microchannel packaged thermal pressure difference and flow rate fusion sensor array. Fig.11 As shown, the following steps are included:

[0062] S1, spin-coat the first layer of PI on the silicon wafer, i.e. Si, and solidify it; PI (Polyimide), i.e. polyimide, is a high-performance thermoplastic or thermosetting polymer, known for its excellent thermal stability, chemical stability and mechanical properties. PI materials are widely used in many fields such as electronics, aerospace, automobiles, microelectronics and semiconductor manufacturing.

[0063] S2, spin-coat photoresist on the first layer of PI and photoetch out electrode windows, then sputter Au / Cr layer as the electrodes of the heating module and the temperature measurement module; Au / Cr layer (Gold / Chromium Layer) refers to a double-layer structure consisting of a layer of chromium (Cr) and a layer of gold (Au), which is commonly used in microelectronics, semiconductor manufacturing, optical devices and other fields.

[0064] S3, placing the silicon wafer into NMP solution and heating it for degumming treatment; NMP solution, whose Chinese name is N-methylpyrrolidone, is a colorless and transparent organic solvent that is very common in chemical and industrial applications.

[0065] S4, spin-coat photoresist on the Au / Cr layer and the first layer of PI and photolithograph the temperature measurement window and the heating window, and then sputter Pt / Ti; the Pt / Ti layer (Platinum / Titanium Layer) refers to a double-layer structure consisting of a layer of titanium (Ti) and a layer of platinum (Pt), which is commonly used in microelectronics, semiconductor manufacturing, catalysis and surface coating and other fields.

[0066] S5, placing the silicon wafer in an NMP solution and heating it for degumming treatment;

[0067] S6, spin coating a second PI layer on the Au / Cr layer, the first PI layer and the Pt / Ti layer, and curing;

[0068] S7, spin-coat photoresist on the second layer of PI and photolithograph the groove window, then RIE etch the second layer of PI to the surface of the silicon wafer to form a groove structure; RIE etching (Reactive Ion Etching) is a dry etching technology used in the process of microelectronics and semiconductor manufacturing. RIE etching uses chemical reactions and physical bombardment in plasma to accurately remove materials, and is one of the important means of manufacturing microstructures.

[0069] S8, thermally pressing and bonding the upper pipeline layer 4 and the device layer 3, and coating the upper pipeline layer 4 with a layer of perfluoroethylene-propylene copolymer;

[0070] S9, hot-pressing and bonding the upper pipe layer 4 to the top of the encapsulation layer 5, and coating the encapsulation layer 5 with a layer of perfluoroethylene-propylene copolymer;

[0071] S10, peeling the device layer 3 off the silicon wafer;

[0072] S11, hot-pressing and bonding the lower pipeline layer 2 to the bottom of the device layer 3, and coating the lower pipeline layer 2 with a layer of perfluoroethylene-propylene copolymer;

[0073] S12, hot-pressing and bonding the lower pipe layer 2 and the base layer 1, and coating the base layer 1 with a layer of perfluoroethylene-propylene copolymer.

[0074] The present invention realizes the integrated manufacturing of thermal pressure difference / flow velocity sensor array through the arrangement of thermal sensor array and multi-layer PI microchannel bonding. The skin with thermal sensor as the main body made by this method has the advantages of being softer, thinner and more stable, and can be attached to the wing surface to measure the pressure difference / flow velocity information of each point on the wing surface. The thermal sensor element is encapsulated in the microchannel, and the thermal differential pressure sensor made has the advantages of ultra-high sensitivity and wide range. By adjusting the constant temperature difference circuit, the sensitivity and range of a single device can be controlled and greatly adjusted. The entire array is composed of PI materials with extremely low thermal conductivity. Through the multi-layer PI bonding process, the suspended structure of the thermal sensitive element is realized, which greatly reduces the heat conduction loss and improves the heat convection efficiency. The existing flexible sensor array is limited by the sensing mechanism, the sensor is difficult to encapsulate and protect, and the sensing units are all exposed on the surface. The design adopts a multi-layer PI bonding process to realize the packaging of a large-area flexible differential pressure sensor, and the thermal sensor unit is sealed in a flexible pipeline to realize the measurement of pressure difference.

[0075] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A thermal pressure difference and flow velocity fusion sensor array packaged in a microfluidic channel, characterized in that: include: a device layer, on which a plurality of flow velocity sensors and a plurality of differential pressure sensors are arranged; A pipeline layer, wherein the upper and lower ends of the device layer located at the position of the differential pressure sensor are respectively stacked with one pipeline layer, the pipeline layer is provided with the same number of pipelines as the differential pressure sensors, and the differential pressure sensors are located in the corresponding pipelines; A base layer, the base layer is stacked at the bottom of the pipeline layer below the device layer, and the base layer covers the device layer; The packaging layer is stacked on top of the pipeline layer above the device layer, the packaging layer covers the pipeline of the pipeline layer, and the packaging layer is provided with pressure measuring holes at positions corresponding to both ends of the pipeline, and the pressure measuring holes are connected to the inside of the pipeline.

2. The microchannel packaged thermal pressure difference and flow velocity fusion sensor array according to claim 1, characterized in that: The pipeline layer includes an upper pipeline layer and a lower pipeline layer, the upper pipeline layer is located at the upper end of the differential pressure sensor position, and covers a plurality of the differential pressure sensors, the lower pipeline layer is located at the lower end of the differential pressure sensor position, and the differential pressure sensor is located in a pipeline opened between the upper pipeline layer and the lower pipeline layer; the lower pipeline layer is provided with an extension portion, the extension portion extends to cover the position of the flow velocity sensor, the extension portion is provided with square through holes of the same number as the flow velocity sensors, and each of the square through holes is correspondingly provided with one flow velocity sensor.

3. The microchannel packaged thermal pressure difference and flow velocity fusion sensor array according to claim 2, characterized in that: Each of the flow velocity sensors is provided with a heating unit, four temperature measuring units and a temperature compensation unit. The four temperature measuring units are symmetrically arranged around the heating unit, and grooves are arranged between the heating unit and the temperature measuring unit of the flow velocity sensor; the base layer, the grooves and the square through holes form the air flow channel of the flow velocity sensor; the heating unit adopts a serpentine platinum resistor as a heating element; and the temperature measuring unit adopts a serpentine platinum resistor as a calorimetric element.

4. The microchannel packaged thermal pressure difference and flow velocity fusion sensor array according to claim 2, characterized in that: Each of the differential pressure sensors is provided with a heating unit, two temperature measuring units and a temperature compensation unit; the temperature measuring units are symmetrically arranged at both ends of the heating unit, a groove is arranged between the heating unit and the temperature measuring unit of the differential pressure sensor, and the outer contour of the groove is consistent with the shape of the pipeline at the lower pipeline layer; the base layer, the pipeline of the lower pipeline layer, the groove, the pipeline of the upper pipeline layer and the pressure measuring hole of the packaging layer form the airflow channel of the differential pressure sensor; the heating unit and the temperature measuring unit both use serpentine platinum resistors.

5. The microchannel packaged thermal pressure difference and flow velocity fusion sensor array according to claim 3 or 4, characterized in that: The temperature measuring unit is connected to a temperature measuring transmission electrode, and the heating unit is connected to a heating transmission electrode. Both the temperature measuring transmission electrode and the heating transmission electrode are sheet-shaped structures. The temperature measuring transmission electrode and the heating transmission electrode are located on the same plane. The current input end and the current output end of the temperature measuring transmission electrode and the heating transmission electrode are both connected to welding pads, and a plurality of the welding pads are arranged in parallel at one side edge of the device layer.

6. The microchannel packaged thermal pressure difference and flow velocity fusion sensor array according to claim 5, characterized in that: The temperature compensation unit includes a temperature compensation resistor disposed on the device layer, and the temperature compensation resistor is electrically connected to the heating transmission electrode.

7. The microchannel packaged thermal pressure difference and flow velocity fusion sensor array according to claim 6, characterized in that: The temperature compensation resistor is located in the middle of the device layer and is covered by the upper pipeline layer and the lower pipeline layer.

8. The microchannel packaged thermal pressure difference and flow velocity fusion sensor array according to claim 4, characterized in that: The airflow channel comprises a reduced diameter pipeline structure, and the reduction ratio thereof is between 0.3 and 0.

7. The heating unit and the temperature measuring unit of the differential pressure sensor are both located at the reduced diameter pipeline structure of the airflow channel.

9. The microchannel packaged thermal pressure difference and flow velocity fusion sensor array according to claim 1, characterized in that: The materials of the base layer, the pipeline layer, the device layer and the packaging layer are all polyimide.

10. A method for manufacturing a thermal pressure difference and flow velocity fusion sensor array packaged in a microfluidic channel, characterized in that: The steps include: S1, spin coating the first layer of PI on the silicon wafer and curing; S2, spin-coating photoresist on the first layer of PI and photolithography electrode windows, and then sputtering Au / Cr layers as electrodes for the heating module and the temperature measurement module; S3, placing the silicon wafer in an NMP solution and heating it for degumming treatment; S4, spin-coating photoresist on the Au / Cr layer and the first PI layer and photolithography out the temperature measurement window and the heating window, and then sputtering Pt / Ti; S5, placing the silicon wafer in an NMP solution and heating it for degumming treatment; S6, spin coating a second PI layer on the Au / Cr layer, the first PI layer and the Pt / Ti layer, and curing; S7, spin-coating photoresist on the second layer of PI and photolithography a groove window, and then RIE etching the second layer of PI to the surface of the silicon wafer to form a groove structure; S8, thermally pressing and bonding the upper pipeline layer and the device layer, and coating the upper pipeline layer with a layer of perfluoroethylene-propylene copolymer; S9, hot-pressing and bonding the upper pipeline layer to the top of the encapsulation layer, and coating the encapsulation layer with a layer of perfluoroethylene-propylene copolymer; S10, peeling the device layer off the silicon wafer; S11, hot-pressing and bonding the lower pipeline layer to the bottom of the device layer, and coating the lower pipeline layer with a layer of perfluoroethylene-propylene copolymer; S12, hot-pressing and bonding the lower pipe layer to the base layer, and coating the base layer with a layer of perfluoroethylene-propylene copolymer.

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