MEMS thermal flow velocity sensor based on TGV technology and convenient to integrate and package and preparation method of MEMS thermal flow velocity sensor

Abstract

The invention discloses a TGV technology-based MEMS thermal flow velocity sensor convenient for integrated packaging and a preparation method thereof. The TGV technology-based MEMS thermal flow velocity sensor comprises a glass substrate, a metal conductive through column, a side wall metal seed layer, an adhesion layer, a temperature measurement resistor, a central heating resistor, an insulation protection layer and a pressure welding block. Wherein the TGV conductive metal through column is formed by performing through hole forming on the glass and then performing side wall seed layer deposition and metal electroplating and filling processes. According to the metal conductive through column, an electric signal of a sensor chip on the front surface of the chip can be transmitted to the back surface of the chip, so that the chip can be conveniently integrated and packaged with other sensor chips, and the development requirements of MEMS devices in the multi-sensor integration and multi-functionalization directions are met. A traditional thermal type MEMS flow velocity sensor is manufactured on a silicon substrate, the sensor is manufactured on a glass through hole TGV substrate, the low heat conductivity coefficient of the glass substrate inhibits invalid heat diffusion of a heating resistor in the center of the thermal type flow velocity sensor, and the sensitivity and performance of the device are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of flow velocity sensor preparation, and in particular relates to a MEMS thermal flow velocity sensor based on TGV technology that is convenient for integrated packaging and a preparation method thereof. Background Art

[0002] MEMS thermal flow sensors have the advantages of fast response, high accuracy and low power consumption. Due to its miniaturization, it is widely used in microfluidic control, biomedicine, environmental detection and industrial automation. The advancement of CMOS process technology makes it possible to process MEMS devices in batches, and makes MEMS devices develop towards multi-sensor integration and multi-function.

[0003] The working principle of thermal flow rate sensor involves many fields such as fluid flow / heat transfer, solid heat transfer and subsequent interface circuits. A typical thermal flow rate sensor uses the principle of thermal temperature difference to measure information such as fluid flow rate. Its structure includes a heating resistor in the center of the chip, which is controlled by the circuit to maintain a fixed power heating or fixed temperature difference, and generates a symmetrically distributed thermal field under no flow conditions. Temperature measuring resistors of the same size and resistance are placed at equal distances on both sides (one-dimensional direction) or around (two-dimensional direction) of the central heating resistor. When there is fluid flow, the originally symmetrically distributed temperature field will change due to the forced convection heat transfer of the fluid. Using the temperature coefficient change characteristics of the resistor, the subsequent interface circuit will capture the voltage difference caused by the temperature difference between the two temperature measuring resistors in the X-axis (or Y-axis) direction, and then convert it into flow rate information to achieve the measurement of fluid flow rate.

[0004] With the development of advanced packaging technology, through silicon via (TSV) technology has developed rapidly, making integrated circuit packaging technology move towards 3D. However, TSV technology has the problems of high cost of deep silicon etching, the need for additional electrical isolation layer and poor signal integrity, so through glass via (TGV) technology was proposed. Compared with TSV, TGV can not only provide vertical electrical signal transmission that enables MEMS devices to develop in the direction of multi-sensor integration and multi-function, but also has the following obvious advantages: low cost, excellent dielectric properties, no need for additional deposition of insulating layer, flexible and controllable thickness and surface roughness, excellent mechanical properties, etc.

[0005] Traditional MEMS thermal flow sensors have a serious problem of ineffective heat dissipation of the silicon substrate, which leads to a decrease in sensitivity. In order to increase the output, the design of a suspended film structure will increase the output but reduce the overall reliability of the device. At the same time, the traditional lead method is to bond the chip surface through wires, which does not meet the needs of future sensor integration and multifunctionality. Summary of the invention

[0006] The purpose of the present invention is to provide a MEMS thermal flow velocity sensor and its preparation method that are easy to integrate and package based on TGV technology. The metal conductive column system-level three-dimensional (3D) packaging formed by the TGV technology based on glass perforation provides a faster and denser signal interface packaging solution than planar wire bonding, which is conducive to the miniaturization and integration development needs of sensor chips; at the same time, the glass substrate provides higher reliability, stability and other mechanical properties than the traditional silicon substrate, effectively reducing the original ineffective heat loss of the silicon substrate, so that the sensitivity of the thermal flow velocity sensor is improved compared to the single silicon substrate. In addition to the above gain effect, the excellent electrical properties of the glass substrate can effectively improve the integrity of the transmission signal to solve the technical problems mentioned in the background technology.

[0007] In order to solve the above technical problems, the specific technical solutions of the present invention are as follows: A MEMS thermal flow velocity sensor based on TGV technology that is easy to integrate and package includes: a glass substrate, a metal conductive via with a TGV structure, an adhesive layer, a central heating resistor, a temperature measuring resistor, a welding block, a sidewall metal seed layer, and an insulating protective layer, wherein the adhesive layer is between the central heating resistor, the temperature measuring resistor and the glass substrate to enhance the adhesion to the glass substrate. The shapes of the central heating resistor and the surrounding temperature measuring resistors have different design patterns according to the actual use scenario; an insulating protective layer is provided on the surface of the central heating resistor and the temperature measuring resistor; the central heating resistor, the temperature measuring resistor and the welding block transmit signals through gold wires, and transmit signals to the back of the substrate through the front welding block via the metal vertical conductive via.

[0008] The central heating resistor is located on the adhesive layer and distributed at the midline or center of the flow velocity sensor, and an insulating protective layer is provided on the surface of the central heating resistor; The temperature measuring resistors are located on the adhesive layer, and are symmetrically distributed on both sides or around the central heating resistor, depending on whether the designed flow velocity sensor is measured in one-dimensional or two-dimensional directions.

[0009] The central heating resistor and the temperature measuring resistor are both distributed on the same side of the sensor structure.

[0010] There are multiple pairs of pressure welding blocks distributed on the upper and lower sides of the sensor, and each metal conductive column has one at each end, which is used to connect the central heating resistor, the temperature measuring resistor and the peripheral interface circuit.

[0011] The central heating resistor and the temperature measuring resistor are in the shape of a rectangle, square, circle or the like.

[0012] The insulating protective layer for protection is provided on the central heating resistor and the temperature measuring resistor; The glass substrate is obtained by TGV through-hole technology and TGV metal electroplating filling technology; Furthermore, the original material of the glass substrate is one of SCHOTT AF32 eco, Corning HPFS 7980 series, and SCHOTT Borofloat 33 glass.

[0013] Furthermore, in the process of forming a metal conductive via substrate with TGV from a glass substrate, there are steps of TGV glass through hole forming, through hole sidewall metal deposition and TGV electroplating metal filling through hole process, wherein the TGV glass through hole forming process includes sandblasting, photosensitive glass method, focused discharge method, plasma etching method, laser ablation method, electrochemical discharge machining method and laser induced etching method.

[0014] Furthermore, the temperature measuring resistors are divided into one-dimensional measurement and two-dimensional measurement. For one-dimensional measurement, the temperature measuring resistors are required to be symmetrically distributed in the left and right or upper and lower positions with the central heating resistor as the center, and set as one or more pairs; for two-dimensional measurement, the temperature measuring resistors are required to be symmetrically distributed in the left and right or upper and lower positions with the central heating resistor as the center, and set as one or more pairs.

[0015] Furthermore, the shape of the central heating resistor is rectangular, square, circular or a shape optimized by a neural network, and the central heating resistor is located at the exact center of the sensor.

[0016] Furthermore, the materials of the central heating resistor and the temperature measuring resistor are metal or polysilicon, preferably platinum metal; Furthermore, the sidewall metal seed layer is located between the metal conductive via and the glass substrate, and is manufactured using a magnetron sputtering technique, so that the sidewall metal seed layer is tightly attached to the sidewall of the through hole.

[0017] Furthermore, the material of the metal conductive via is one of copper, gold, titanium, chromium, aluminum, platinum or tungsten, and the preparation process is electroplating; the internal structure of the metal conductive via is continuous, and is a fully filled type, a sub-conformal filled type, a conformal filled type, or an ultra-conformal filled type.

[0018] Furthermore, the adhesion layer, the temperature measuring resistor, and the central heating resistor are made by one of magnetron sputtering technology, metal evaporation technology or electroplating technology, and the formation of the temperature measuring resistor and the central heating resistor pattern is made by RIE, IBE dry etching or wet etching process.

[0019] Furthermore, the material of the insulating protection layer is one or both of silicon oxide and silicon nitride, and is formed by a technique of plasma enhanced chemical vapor deposition PECVD or low pressure chemical vapor deposition LPCVD.

[0020] Furthermore, the adhesive layer is located between the central heating resistor, the temperature measuring resistor and the glass substrate, in order to enhance the bonding force between the resistor and the substrate, and the material is preferably titanium.

[0021] The preparation method of the MEMS thermal flow velocity sensor based on TGV technology for easy integrated packaging of the present invention comprises the following steps: S1. Prepare glass samples, double-sided polishing, and surface treatment and cleaning of samples before use to ensure that surface contaminants are eliminated; S2, implementing a pulsed laser processing process to perform laser radiation modification on the glass substrate area to be processed; It should be pointed out in particular that the above-mentioned step S1 and step S2 are one of the feasible process routes for realizing TGV glass through-hole formation, which should also include sandblasting, photosensitive glass method, focused discharge method, plasma etching method, laser ablation method, and electrochemical discharge machining method. For the sake of convenience of example, only the laser induced etching method for glass through-hole formation is introduced here.

[0022] S3, preparing a wet etching solution to etch the laser-modified glass substrate to form a hollow through column penetrating the glass TGV; S4, performing a metal deposition process on the etched glass substrate, so that a sidewall metal seed layer of the metal layer to be plated is attached to the sidewall of the empty through column of the glass TGV, providing a growth interface for the next metal electroplating process; S5, performing a TGV electroplating metal filling process to fill the through hole with metal to form a metal conductive through-column that runs through the substrate; S6, performing thinning and polishing processes to remove the excess metal layer on the surface of the glass substrate; S7, implementing a metal deposition technology to deposit metals for forming an adhesion layer, a temperature measuring resistor, a central heating resistor, and a lead layer respectively; S8, spin-coating photoresist, and after exposure and development, defining the patterns of each layer, and then using an etching process to form a central heating resistor, a temperature measuring resistor, leads and a bonding pad; S9, performing plasma enhanced chemical vapor deposition (PECVD) or low pressure chemical vapor deposition (LPCVD) on the front side of the glass substrate to deposit an insulating protective layer; S10, depositing a metal layer on the back side, spin-coating a photoresist, exposing and developing the photoresist to define a back side bonding pad area, and forming a bonding pad by etching.

[0023] The present invention discloses a MEMS thermal flow velocity sensor that is easy to integrate and package based on TGV technology and a preparation method thereof, which has the following advantages: the glass substrate has higher mechanical properties; at the same time, due to the low thermal conductivity of the glass itself, the ineffective heat dissipation of the central heating resistor is effectively avoided, thereby improving the sensitivity of the device. The TGV hole forming technology and the TGV through-hole electroplating filling technology are implemented at the same time to form a metal conductive via connecting the upper and lower sides of the substrate, providing a 3D packaging solution to meet the development needs of MEMS sensor integration and multifunctionalization. In the process of forming the TGV metal conductive via, due to the excellent electrical properties of the glass, there is no need to deposit an additional electrical isolation layer on the inner wall of the through hole, so that the substrate loss and parasitic effects are greatly reduced, and the completeness of the transmission signal is effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the side structure of a MEMS thermal flow velocity sensor based on TGV technology that is easy to integrate and package according to an embodiment of the present invention; Figure 2 It is a schematic cross-sectional structure diagram of the structure obtained in step S1 of the manufacturing method disclosed in the embodiment of the present invention; Figure 3 It is a schematic cross-sectional structure diagram of the structure obtained in step S2 of the manufacturing method disclosed in the embodiment of the present invention; Figure 4 It is a schematic cross-sectional structure diagram of the structure obtained in step S3 of the manufacturing method disclosed in the embodiment of the present invention; Figure 5 It is a schematic cross-sectional structure diagram of the structure obtained in step S4 of the manufacturing method disclosed in the embodiment of the present invention; Figure 6 It is a schematic cross-sectional structure diagram of the structure obtained in step S5 of the manufacturing method disclosed in the embodiment of the present invention; Figure 7 It is a schematic cross-sectional structure diagram of the structure obtained in step S6 of the manufacturing method disclosed in the embodiment of the present invention; Figure 8 It is a schematic cross-sectional structure diagram of the structure obtained in step S7 of the manufacturing method disclosed in the embodiment of the present invention; Fig. 9 It is a schematic cross-sectional structure diagram of the structure obtained in step S8 of the manufacturing method disclosed in the embodiment of the present invention; Fig.10 It is a schematic cross-sectional structure diagram of the structure obtained in step S9 of the manufacturing method disclosed in the embodiment of the present invention; Fig.11 It is a schematic cross-sectional structure diagram of the structure obtained in step S10 of the manufacturing method disclosed in the embodiment of the present invention; Fig.12A flow chart of a method for preparing a MEMS thermal flow velocity sensor that is convenient for integrated packaging based on TGV technology disclosed in an embodiment of the present invention; Fig.13 A schematic diagram of the structure of a central heating resistor, a temperature measuring resistor (in one-dimensional direction), a lead wire and a metal conductive via column of a MEMS thermal flow velocity sensor based on TGV technology for easy integration and packaging disclosed in an embodiment of the present invention; Fig.14 A schematic diagram of the structure of a central heating resistor, a temperature measuring resistor (two-dimensional direction, square central heating resistor), a lead wire and a metal conductive via column of a MEMS thermal flow velocity sensor based on TGV technology for easy integration and packaging disclosed in an embodiment of the present invention; Fig.15 A schematic diagram of the structure of a central heating resistor, a temperature measuring resistor (two-dimensional direction, circular central heating resistor), a lead wire and a metal conductive via column of a MEMS thermal flow velocity sensor based on TGV technology for easy integration and packaging disclosed in an embodiment of the present invention; Markings in the figure are as follows: 100, glass substrate; 200, metal conductive via; 210, side wall metal seed layer; 220, hollow via; 310, adhesion layer; 320, central heating resistor; 330, temperature measuring resistor; 340, lead layer; 350, welding block; 400, insulating protective layer. DETAILED DESCRIPTION

[0025] In order to better understand the purpose, structure and function of the present invention, the following is a further detailed description of a MEMS thermal flow velocity sensor based on TGV technology that is easy to integrate and package and a preparation method thereof in conjunction with the accompanying drawings.

[0026] like Figure 1 As shown, the present invention proposes a MEMS thermal flow rate sensor which is easy to integrate and package based on TGV technology. The sensor includes: a glass substrate 100, a metal conductive via 200, a sidewall metal seed layer 210, an adhesion layer 310, a central heating resistor 320, a temperature measuring resistor 330, a lead layer 340, an insulating protection layer 400, and a welding block 350, wherein: the temperature measuring resistor layer 330 and the central heating resistor layer 320 are located on the glass substrate 100, and an adhesion layer 310 is also deposited between the glass substrate 100 and the temperature measuring resistor 330 and the central heating resistor 320 to enhance the adhesion between the layers; welding blocks 350 are provided at the upper and lower ports of the metal conductive via, and the sidewall of the metal conductive via is provided with a sidewall metal seed layer 210.

[0027] like Fig.13 The figure shows a schematic diagram of the structure of a central heating resistor, a temperature measuring resistor (in one-dimensional direction), leads and a metal conductive via column of a MEMS thermal flow velocity sensor based on TGV technology for easy integration and packaging disclosed in an embodiment of the present invention.

[0028] Fig.14 A schematic diagram of the structure of a central heating resistor, a temperature measuring resistor (two-dimensional direction, square central heating resistor), leads and metal conductive vias of a MEMS thermal flow velocity sensor based on TGV technology for easy integration and packaging disclosed in an embodiment of the present invention.

[0029] Fig.15 A schematic diagram of the structure of a central heating resistor, a temperature measuring resistor (two-dimensional direction, circular central heating resistor), leads and a metal conductive via column of a MEMS thermal flow velocity sensor that is easy to integrate and package based on TGV technology disclosed in an embodiment of the present invention.

[0030] like Figure 13-15 As shown, the central heating resistor 320 is located at the center of the chip, and can be rectangular, square, circular, etc., depending on whether the flow velocity in one-dimensional direction or two-dimensional direction can be measured; The temperature measuring resistors 330 are symmetrically distributed around the central heating resistor 320. Fig.13 As shown, for a one-dimensional flow velocity sensor, it includes an X-axis upstream temperature measuring resistor and an X-axis downstream temperature measuring resistor; Figure 14-15 As shown, for the two-dimensional flow velocity sensor, it includes an X-axis upstream temperature measuring resistor, an X-axis downstream temperature measuring resistor, a Y-axis upstream temperature measuring resistor, and a Y-axis downstream temperature measuring resistor; The welding blocks 350 are distributed on the upper and lower sides of each metal conductive via 200 and are used to connect with the peripheral interface circuit; The glass substrate 100 is a substrate that has been laser modified, corroded and perforated, and metal filled, and has good support and signal transmission capabilities. The central heating resistor 320 and the temperature measuring resistor 330 are distributed on the glass substrate 100; The insulating protection layer 400 is located on the temperature measuring resistor 330, the central heating resistor 320, the upper layer bonding pad 350 and other remaining areas of the glass substrate 100, and is used to protect the heating resistor, the temperature measuring resistor, the bonding pad and the substrate; The central heating resistor 430 and the temperature measuring resistor 420 are made of metal through deposition and etching, and are covered by the insulating protective layer 400 to avoid being exposed to the environment, and have good chemical stability and resistance characteristics; The sidewall metal seed layer 210 located on the outer sidewall of the metal conductive via 200 is deposited by a metal sidewall deposition technique. The layer should be well attached to the sidewall of the glass through hole. The function of the sidewall metal seed layer 210 is to provide a necessary seed layer for the metal electroplating process step. The metal conductive via 200 is grown on the inner side of the sidewall metal seed layer 210 and is made by electroplating. It is continuous from top to bottom and penetrates the internal structure. The upper and lower ends are provided with welding blocks 350 and are connected to the front device structure and the external circuit board through leads. The welding blocks 350 are distributed on the upper and lower sides of the chip and are located on the upper and lower surfaces of the metal conductive vias 200, and are used to form ohmic contacts with the surfaces of the metal vias to form a signal channel; The present invention also provides a method for preparing a MEMS thermal flow velocity sensor that is convenient for integrated packaging based on TGV technology, such as Fig.12 As shown, the method comprises the following steps: S1. Prepare glass samples, double-sided polishing, and surface treatment and cleaning of the samples before use to ensure that surface contaminants are eliminated, such as Figure 2 As shown; Specifically, the glass is borosilicate glass, preferably AF32 eco or HPFS 7980 glass; the glass surface must have extremely high cleanliness before laser modification, and the sample is cleaned in sequence using deionized water, concentrated sulfuric acid / hydrogen peroxide, acetone, ethanol and other chemical reagents, and then blown dry and placed in a dry and clean environment.

[0031] S2, implement a pulse laser processing process to modify the glass substrate 100 by laser radiation in the area to be processed, such as Figure 3 As shown; Specifically, the laser modification process steps require the determination of parameters such as laser energy, pulse duration, laser focusing plane, and initial diameter of the through-column.

[0032] It should be pointed out in particular that the above-mentioned steps S1 and S2 are one of the feasible process routes for realizing TGV glass through-hole formation, which should also include sandblasting, photosensitive glass method, focused discharge method, plasma etching method, laser ablation method, and electrochemical discharge machining method. For the sake of convenience of example, only the laser induced etching method TGV glass through-hole formation technology is introduced here.

[0033] S3, preparing a wet etching solution to etch the laser-modified glass substrate 100 to form a through-glass TGV hollow column 220, such as Figure 4 As shown; Specifically, the etching solution is a hydrofluoric acid solution (HF) or a potassium hydroxide (KOH) solution, and the etching process should control the etching solution concentration, temperature, time and other process parameters according to the target diameter of the through hole and the etching depth of the through hole.

[0034] S4, performing a metal deposition process on the etched glass substrate 100, so that a sidewall metal seed layer 210 of the metal layer to be plated is attached to the sidewall of the TGV glass hollow column 220, providing a growth interface for the next metal electroplating process, such as Figure 5 As shown; Specifically, to ensure the adhesion effect of the sidewall metal seed layer 210, the preferred process is magnetron sputtering.

[0035] S5, implement TGV electroplating filling process to fill the through hole with metal, forming a metal conductive through column 200 that runs through the substrate. Figure 6 As shown; S6, performing thinning and polishing processes to remove the excess metal layer on the surface of the glass substrate 100, such as Figure 7 As shown; S7, implement metal deposition technology to deposit metals used to form an adhesion layer, a resistance layer and a lead layer, such as Figure 8 As shown; Specifically, Ti metal is generally selected as the adhesion layer 310 , Pt metal is used to form the central heating resistor 320 and the temperature measuring resistor 330 , and Au metal is used as the lead wire and the bonding pad 350 .

[0036] S8, spin-coating photoresist, after exposure and development, the patterns of each layer are defined, and then the central heating resistor 320, the temperature measuring resistor 330, the lead wire and the pressure welding block 350 are formed by etching process, such as Fig. 9 As shown; Specifically, Ti is used as adhesion, Pt is used as a resistance layer, and Au is used as a lead layer. After the metal deposition process of the previous step is completed in sequence, preferably, the gold lead and the pad area are etched with a gold etching solution; preferably, a dry etching IBE is used to etch the Pt resistance area (including the central heating resistor and the surrounding temperature measuring resistor), and after the etching is completed, a rapid thermal annealing process should be provided to ensure the ohmic contact between the metal conductive column 200 and the pad 350 (the annealing temperature does not exceed the glass softening temperature).

[0037] S9, performing PECVD or LPCVD deposition of an insulating protective layer 400 on the front side of the glass substrate 100, such as Fig.10 As shown; S10, depositing a metal layer on the back side, and after exposure and development of the spin-coated photoresist, defining the back side bonding pad 350 area, and forming the bonding pad 350 by etching process, such as Fig.11 shown.

[0038] It is to be understood that the present invention is described by some embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. A MEMS thermal flow velocity sensor based on TGV technology that is easy to integrate and package, characterized in that: include: A glass substrate (100), a metal conductive via with a TGV structure (200), a sidewall metal seed layer (210), an adhesion layer (310), a central heating resistor (320), a temperature measuring resistor (330), a lead layer (340), an insulating protective layer (400), and a welding block (350); The adhesive layer (310) is located on the glass substrate (100) and is used to enhance the adhesion to the glass substrate (100); The central heating resistor (320) is located on the adhesive layer (310) and is distributed at the midline or center of the flow rate sensor, and an insulating protective layer (400) is provided on the surface of the central heating resistor (320); The temperature measuring resistor (330) is located on the adhesive layer (310) and is symmetrically distributed on both sides or around the central heating resistor (320); an insulating protective layer (400) is provided on the surface of the temperature measuring resistor (330); The sidewall metal seed layer (210) is located at the periphery of the metal conductive via (200); The metal conductive via (200) penetrates the upper and lower sides of the glass substrate (100), has a continuous internal structure, a height equal to the thickness of the substrate, and is provided with pressure welding blocks (350) at its upper and lower ends; The lead layer (340) is an upper layer of the central heating resistor (320) and the temperature measuring resistor (330). The lead layer (340) is an electrical signal channel of the central heating resistor (320) and the temperature measuring resistor (330). The electrical signal is connected to an external circuit through a front welding block (350) and a metal conductive via (200).

2. The MEMS thermal flow velocity sensor based on TGV technology and convenient for integrated packaging according to claim 1 is characterized in that: The original material of the glass substrate (100) is one of SCHOTT AF32 eco, Corning HPFS 7980 series, and SCHOTT Borofloat 33 glass.

3. The MEMS thermal flow velocity sensor based on TGV technology and convenient for integrated packaging according to claim 1 is characterized in that: In the process of forming a metal conductive through-hole (200) substrate with a TGV on a glass substrate (100), the steps of forming a TGV glass through-hole, depositing metal on the through-hole sidewalls, and filling the through-holes with TGV electroplated metal are provided, wherein the TGV glass through-hole forming process includes a sandblasting method, a photosensitive glass method, a focused discharge method, a plasma etching method, a laser ablation method, an electrochemical discharge machining method, or a laser induced etching method.

4. The MEMS thermal flow velocity sensor based on TGV technology and convenient for integrated packaging according to claim 1 is characterized in that: The temperature measuring resistor (330) is divided into two types: one-dimensional measurement and two-dimensional measurement. For one-dimensional measurement, the temperature measuring resistor (330) is required to be symmetrically distributed in two positions on the left and right or above and below the central heating resistor (320) with one or more pairs. For two-dimensional measurement, the temperature measuring resistor (330) is required to be symmetrically distributed in four positions on the left and right or above and below the central heating resistor (320) with one or more pairs.

5. The MEMS thermal flow velocity sensor based on TGV technology and convenient for integrated packaging according to claim 1 is characterized in that: The shape of the central heating resistor (320) is rectangular, square, circular, or a shape optimized by a neural network, and the central heating resistor (320) is located at the exact center of the sensor.

6. The MEMS thermal flow velocity sensor based on TGV technology and convenient for integrated packaging according to claim 1, characterized in that: The side wall metal seed layer (210) is located between the metal conductive via (200) and the glass substrate (100), and is manufactured using a magnetron sputtering technique, so that the side wall metal seed layer (210) is tightly attached to the side wall of the via.

7. The MEMS thermal flow velocity sensor based on TGV technology and convenient for integrated packaging according to claim 1, characterized in that: The material of the metal conductive via (200) is one of copper, gold, titanium, chromium, aluminum, platinum or tungsten, and the preparation process is electroplating; the internal structure of the metal conductive via (200) is continuous, and is a fully filled type, a sub-conformal filled type, a conformal filled type or an ultra-conformal filled type.

8. The MEMS thermal flow velocity sensor based on TGV technology and convenient for integrated packaging according to claim 1, characterized in that: The adhesion layer (310), the temperature measuring resistor (330), and the central heating resistor (320) are manufactured by one of magnetron sputtering technology, metal evaporation technology, or electroplating technology, and the patterns of the temperature measuring resistor (330) and the central heating resistor (320) are formed by RIE, IBE dry etching, or wet etching process.

9. The MEMS thermal flow velocity sensor based on TGV technology and convenient for integrated packaging according to claim 1, characterized in that: The material of the insulating protection layer (400) is one or both of silicon oxide and silicon nitride, and is formed by a technique of plasma enhanced chemical vapor deposition (PECVD) or low pressure chemical vapor deposition (LPCVD).

10. A method for preparing a MEMS thermal flow velocity sensor based on TGV technology that is easy to integrate and package, used for a MEMS thermal flow velocity sensor based on TGV technology that is easy to integrate and package as claimed in any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Prepare glass samples, double-sided polishing, and surface treatment and cleaning of samples before use to ensure that surface contaminants are eliminated; S2, implementing a pulse laser processing process to perform laser radiation modification on the glass substrate (100) in the area to be processed; S3, preparing a wet etching solution to etch the laser-modified glass substrate (100) to form a hollow through column (220) penetrating the glass TGV; S4, performing a sidewall metal deposition process on the etched glass substrate (100), so that a sidewall metal seed layer (210) of a metal layer to be plated is attached to the sidewall of the hollow through-column (220) of the glass TGV, providing a growth interface for the metal electroplating process in step S5; S5, performing a TGV electroplating metal filling process to fill the through hole with metal, thereby forming a metal conductive through column (200) that penetrates the glass substrate (100) from top to bottom; S6, performing thinning and polishing processes to remove the excess metal layer on the surface of the glass substrate (100); S7, implementing a metal deposition technology to deposit metals for forming an adhesion layer (310), a temperature measuring resistor (330), a central heating resistor (320) and a lead layer (340); S8, spin coating the photoresist, and after exposure and development, the patterns of each layer are defined, and then an etching process is used to form a central heating resistor (320), a temperature measuring resistor (330), leads and a bonding pad (350); S9, performing PECVD or LPCVD deposition of an insulating protective layer (400) on the front surface of the glass substrate (100); S10, depositing a metal layer on the back side of the sensor, spin-coating a photoresist, and defining a back side pressure welding block (350) area after exposure and development, and forming the pressure welding block (350) by an etching process.

Images