阅读说明：本技术 一种空心微针阵列芯片及其制备方法 (Hollow microneedle array chip and preparation method thereof ) 是由 张兴虎 王力 于 2021-08-06 设计创作，主要内容包括：本发明提供一种空心微针阵列芯片及其制备方法,包括：基板,所述基板包括相对的正面和背面；微针,所述微针位于所述基板的正面,所述微针包括针尖、针孔和针面,所述针面向所述基板倾斜设定角度；沟槽,所述沟槽位于所述微针外周且半包裹所述微针；导流槽,所述导流槽位于所述基板的背面且与所述针孔连通。本发明通过在基板上设置沟槽和导流槽以及将针面向基板倾斜设定角度,能够实现微针的批量生产以及解决难以刺入皮肤或达到皮内深度的技术问题。(The invention provides a hollow microneedle array chip and a preparation method thereof, wherein the preparation method comprises the following steps: a substrate comprising opposing front and back sides; the micro-needle is positioned on the front surface of the substrate and comprises a needle point, a needle hole and a needle surface, and the needle surface inclines towards the substrate by a set angle; a groove located at the periphery of the microneedle and semi-wrapping the microneedle; the flow guide groove is located on the back face of the substrate and communicated with the needle hole. According to the invention, the grooves and the guide grooves are arranged on the substrate, and the needles face the substrate in an inclined set angle, so that the mass production of the microneedles can be realized, and the technical problem that the microneedles are difficult to penetrate into the skin or reach the intradermal depth can be solved.)

1. A hollow microneedle array chip comprising:

a substrate comprising opposing front and back sides;

the micro-needle is positioned on the front surface of the substrate and comprises a needle point, a needle hole and a needle surface, and the needle surface inclines towards the substrate by a set angle;

a groove located at the periphery of the microneedle and semi-wrapping the microneedle;

the flow guide groove is located on the back face of the substrate and communicated with the needle hole.

2. The hollow microneedle array chip according to claim 1, wherein at least two microneedles constitute a microneedle array, and the microneedles are arranged at a predetermined interval on the substrate.

3. The hollow microneedle array chip according to claim 1, wherein a distance between the tips of the two adjacent microneedles is 600 um.

4. The hollow microneedle array chip of claim 1, wherein the groove is in an inverted V shape.

5. The hollow microneedle array chip according to claim 1, wherein the groove has a depth of 30 to 80um and a width of 50 to 100 um.

6. The hollow microneedle array chip of claim 1, wherein the guiding groove is circular or elliptical, the diameter of the guiding groove is 100um, and the depth is 100-200 um.

7. The hollow microneedle array chip according to claim 1, wherein the diameter of the pinhole of the microneedle is 10 to 100um, and the distance from the pinhole to the tip of the needle tip is 40 um.

8. The hollow microneedle array chip according to claim 1, wherein the microneedles have a height of > 500um and a width of 200-420 um.

9. The hollow microneedle array chip according to claim 1, wherein an inclination angle of the needle face to the base plate is 54.74 °.

10. The hollow microneedle array chip according to claim 1, wherein the substrate has a shape of a rectangular parallelepiped, and has a length of 2300um, a width of 900um and a height of 300 um.

11. A method for preparing a hollow microneedle array chip, comprising:

providing a substrate comprising opposing front and back surfaces;

forming a microneedle on the substrate, wherein the microneedle comprises a needle point, a needle hole and a needle surface, and the needle surface is inclined towards the substrate by a set angle;

a groove is formed on the front surface of the substrate, is formed on the periphery of the microneedle and comprises the microneedle in half;

and a diversion trench is formed on the back surface of the substrate and is communicated with the pinhole.

12. The method of claim 11, wherein forming the substrate comprises:

and forming the diversion trench on the back surface of the substrate through photoetching and etching processes.

13. The method of manufacturing according to claim 12, wherein after the formation of the channels, the method of forming the microneedles comprises:

forming a mask layer on the back surface of the substrate through a deposition process, and etching part of the mask layer to form a first groove;

forming a second groove and a groove on the front surface of the substrate through photoetching and etching processes, wherein the second groove and the first groove are arranged up and down correspondingly;

etching the back surface of the substrate through a deep reactive ion etching process to enable the first groove and the second groove to be communicated to form a pinhole;

after the pinholes are formed, forming a protective layer, wherein the protective layer is formed on the front surface and the back surface of the substrate and the inner wall of the pinholes;

etching the needle point and the needle surface by a silicon anisotropic wet method, wherein the needle surface is inclined towards the substrate by a set angle;

the needle point, the needle surface and the needle hole form the micro-needle;

the microneedles are diced into microneedle arrays by a dicing process.

14. The method of claim 13, wherein the mask layer is made of SiO2, and the protective layer is made of Si3N 4.

15. The method of manufacturing according to claim 13, further comprising, after forming the first recess and before forming the second recess and the trench,

forming photoresist on the front surface of the substrate, and forming a second reserved groove and a reserved groove on the photoresist through a photoetching process;

and removing the photoresist after forming the second groove and the groove.

16. The method of claim 13, further comprising, after forming the protective layer and before forming the tip and face of the needle,

removing the protective layer on the front surface of the substrate, and reserving the protective layer on the back surface of the substrate and the inner wall of the pinhole;

and after the needle point and the needle surface are formed, removing the protective layer.

17. The method of claim 13, wherein after removing the protective layer, further comprising depositing a protective film on the front and back surfaces of the substrate and the inner wall of the pin hole by a high temperature process.

18. The production method according to claim 17, wherein the material of the protective film is SiO 2.

19. The method of claim 13, wherein the needle face is inclined at an angle of 54.74 ° to the substrate.

20. The method of claim 13, wherein the channels are circular or elliptical in shape.

Technical Field

The invention relates to the technical field of semiconductors, in particular to a hollow microneedle array chip and a preparation method thereof.

Background

Hollow microneedle technology is a painless drug delivery technology with a certain internal space that can be filled with an effective drug dispersion or solution. They have holes at their tips, and when inserted into the skin, the drug is directly deposited in the epidermis or upper dermis, and because of its fixed length, the injection depth is precise and does not cause injection pain.

At present, the main manufacturing materials of the hollow microneedle comprise metal, silicon dioxide, glass, nickel, titanium, biodegradable polymer and the like. The metal micro-needle has low manufacturing cost and larger hardness, but the micro-needle head length is difficult to achieve, and painless injection is difficult to realize. The polymer micro-needle is difficult to control the sharpness of the needle point, has poor strength, can generate plastic deformation under the action of certain pressure and has difficulty in puncturing the skin. Some hollow pinholes made of silicon materials have insufficient diameter, insufficient height and poor uniformity. Modern blood analysis devices require at least 5 ul-50 ul/hr of blood for analysis in order to obtain reliable data, and require a pinhole diameter of at least 10-100um in order to achieve adequate flow.

The method for forming the silicon substrate micro-needle mainly comprises laser drilling, is difficult to produce in batches, has high requirements on alignment of a laser and a silicon substrate, and has low yield; most other microneedles have the disadvantages of low needle point sharpness, insufficient height, insufficient needle surface gradient, poor needle point uniformity and the like, and are difficult to penetrate into the skin or reach intradermal depth.

Disclosure of Invention

The invention aims to provide a hollow microneedle array chip and a preparation method thereof, which can at least solve the technical problems that microneedles are difficult to produce in batches and penetrate into the skin or reach the intradermal depth.

In order to achieve the above object, the present invention provides a hollow microneedle array chip comprising:

a substrate comprising opposing front and back sides;

the micro-needle is positioned on the front surface of the substrate and comprises a needle point, a needle hole and a needle surface, and the needle surface inclines towards the substrate by a set angle;

a groove located at the periphery of the microneedle and semi-wrapping the microneedle;

the flow guide groove is located on the back face of the substrate and communicated with the needle hole.

Optionally, a microneedle array is formed by at least two microneedles, the microneedle array is a hollow microneedle array, and the microneedles are arranged on the substrate at a set interval.

Optionally, the distance between the tips of the two adjacent microneedles is 600 um.

Optionally, the groove is in an inverted V shape.

Optionally, the depth of the groove is 30-80 um, and the width is 50-100 um.

Optionally, the guiding gutter is circular or oval, the diameter of guiding gutter is 100um, and the degree of depth is 100 ~ 200 um.

Optionally, the diameter of the pinhole of micropin is 10 ~ 100um, the distance of pinhole apart from the needle point top is 40 um.

Optionally, the height of the microneedle is more than 500um, and the width of the microneedle is 200-420 um.

Optionally, the inclination angle of the needle surface and the substrate is 54.74 °

Optionally, the substrate is a cuboid, and the substrate has a length of 2300um, a width of 900um, and a height of 300 um.

The invention also provides a preparation method of the hollow microneedle array chip, which comprises the following steps:

providing a substrate comprising opposing front and back surfaces;

forming a microneedle on the substrate, wherein the microneedle comprises a needle point, a needle hole and a needle surface, and the needle surface is inclined towards the substrate by a set angle;

a groove is formed on the front surface of the substrate, is formed on the periphery of the microneedle and comprises the microneedle in half;

and a diversion trench is formed on the back surface of the substrate and is communicated with the pinhole.

Optionally, after forming the substrate, the method includes:

and forming the diversion trench on the back surface of the substrate through photoetching and etching processes.

Optionally, after forming the flow guide groove, the method for forming the microneedle comprises:

forming a mask layer on the back surface of the substrate through a deposition process, and etching part of the mask layer to form a first groove;

forming a second groove and a groove on the front surface of the substrate through photoetching and etching processes, wherein the second groove and the first groove are arranged up and down correspondingly;

etching the back surface of the substrate through a deep reactive ion etching process to enable the first groove and the second groove to be communicated to form a pinhole;

after the pinholes are formed, forming a protective layer, wherein the protective layer is formed on the front surface and the back surface of the substrate and the inner wall of the pinholes;

etching the needle point and the needle surface by a silicon anisotropic wet method, wherein the needle surface is inclined towards the substrate by a set angle;

the needle point, the needle surface and the needle hole form the micro-needle;

the microneedles are diced into microneedle arrays by a dicing process.

Optionally, the mask layer is made of SiO2, and the protection layer is made of Si3N 4.

Optionally, after forming the first recess and before forming the second recess and the trench, further comprising,

forming photoresist on the front surface of the substrate, and forming a second reserved groove and a reserved groove on the photoresist through a photoetching process;

and removing the photoresist after forming the second groove and the groove.

Optionally, after forming the protective layer and before forming the needle tip and the needle face, further comprising,

removing the protective layer on the front surface of the substrate, and reserving the protective layer on the back surface of the substrate and the inner wall of the pinhole;

and after the needle point and the needle surface are formed, removing the protective layer.

Optionally, after removing the protective layer, depositing a protective film on the front and back surfaces of the substrate and the inner wall of the pinhole by a high temperature process.

Optionally, the material of the protective film is SiO 2.

Optionally, the inclination angle of the needle surface to the substrate is 54.74 °.

Optionally, the shape of the diversion trench is circular or oval.

The structure of the invention has the advantages that:

according to the invention, the grooves and the flow guide grooves are arranged on the substrate, and the needles face the substrate in an inclined set angle, so that the mass production of the micro-needles can be realized, the good needle point sharpness is realized, and the technical problem that the micro-needles are difficult to penetrate into the skin or reach the intradermal depth is solved.

Furthermore, the height of the microneedle is set to be more than 500um, the uniformity of the diameter of the pinhole and the height of the needle point is less than 2%, the inclination angle between the needle surface and the base plate is 54.74 degrees, and the needle point can completely penetrate into the skin or reach the intradermal depth.

Furthermore, the flow guide groove designed on the back surface of the substrate improves the fixity and the tightness between the fluid pipe and the hollow microneedle array chip, and the design of the flow guide groove improves the fluid flow.

Furthermore, the invention has the advantages of small structure size, high precision, simple flow, low cost and easy batch manufacturing.

The method has the beneficial effects that:

according to the invention, the flow guide groove is formed on the back surface of the substrate, and the groove and the micro-needle are formed on the front surface of the substrate, so that the process flow for manufacturing the hollow micro-needle is simplified, the mass production is realized, and the production cost is reduced.

Furthermore, the invention adopts MEMS technology, the diversion trench, the trench and the pinhole are manufactured by photoetching and etching processes, the height of the micro-needle is more than 500um by wet etching, the inclination angle between the needle surface and the substrate is 54.74 degrees, and the needle point can completely penetrate into the skin or reach the intradermal depth.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic perspective view of a hollow microneedle array chip according to example 1 of the present invention;

fig. 2 is a schematic perspective view of a hollow microneedle array chip according to example 1 of the present invention;

fig. 3 to 12 are schematic structural diagrams corresponding to different steps in the method for manufacturing a hollow microneedle array chip according to embodiment 2 of the present invention.

Reference numerals: 10. a substrate; 11. a first photoresist; 12. a mask layer; 13. a second photoresist; 14. a first groove; 15. a third photoresist; 16. a second groove; 16a and a second reserved groove; 17a, reserving a groove; 17. a trench; 18. a pinhole; 19. a protective layer; 20. a needle tip; 21. needle surface; 31. a protective film; 30. and a diversion trench.

Detailed Description

The hollow microneedle array chip and the method for manufacturing the same according to the present invention will be described in detail with reference to the accompanying drawings and specific examples. The advantages and features of the present invention will become more apparent from the following description and drawings, it being understood, however, that the concepts of the present invention may be embodied in many different forms and should not be construed as limited to the specific embodiments set forth herein. The drawings are in simplified form and are not to scale, but are provided for convenience and clarity in describing embodiments of the invention.

The terms "first," "second," and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein are, for example, capable of operation in other sequences than described or illustrated herein. Similarly, if the method described herein comprises a series of steps, the order in which these steps are presented herein is not necessarily the only order in which these steps may be performed, and some of the described steps may be omitted and/or some other steps not described herein may be added to the method. Although elements in one drawing may be readily identified as such in other drawings, the present disclosure does not identify each element as being identical to each other in every drawing for clarity of description.

Example 1

Referring to fig. 1 and 2, the present embodiment provides a hollow microneedle array chip, and fig. 1 and 2 show a schematic structural view of the hollow microneedle array chip of embodiment 1, and referring to fig. 1 and 2, the hollow microneedle array chip includes:

a substrate 10, said substrate 10 comprising opposing front and back sides;

the micro-needle is positioned on the front surface of the substrate 10 and comprises a needle point 20, a needle hole 18 and a needle surface 21, and the needle surface 21 is inclined to the substrate 10 by a set angle;

a groove 17, the groove 17 being located at the periphery of the microneedle and semi-wrapping the microneedle;

a guiding groove 30, wherein the guiding groove 30 is located on the back surface of the substrate 10 and is communicated with the pinhole 18.

The substrate 10 may be any suitable substrate material known to those skilled in the art, such as a semiconductor substrate material, e.g., silicon, germanium, silicon germanium, gallium arsenide, indium phosphide, etc., and a single crystal silicon wafer with a crystal phase <100> is used in this embodiment.

This chip contains four parts, the micropin array that constitutes by at least two micropins, base plate 10, slot 17 and guiding gutter 30, the micropin is in arrange according to setting for the interval on the base plate 10, in this embodiment, the interval between the needle point 20 of two adjacent micropins is 600 um.

In this embodiment, the slot 17 is the type of falling V, and the slot 17 is located micropin periphery and half parcel the micropin, the degree of depth of slot 17 is 30 ~ 80um, and the width is 50 ~ 100um, sets up slot 17 through the front at base plate 10, can help needle point 20 to pierce completely.

In this embodiment, the guiding groove 30 is circular or elliptical, the diameter of the guiding groove 30 is 100um, and the depth is 100-200 um; the guide groove 30 is arranged on the back of the substrate 10, the guide groove 30 is communicated with the pinhole 18 of the microneedle, the guide groove 30 is arranged on the back of the substrate 10, the fixity and the tightness between the fluid pipe and the hollow microneedle array chip are improved, and the flow of the fluid is improved due to the design of the guide groove 30.

The micro-needle comprises a needle point 20, a needle hole 18 and a needle surface 21, wherein the needle surface 21 is inclined towards the substrate 10 by a set angle.

Specifically, the diameter of a pinhole 18 of the microneedle is 10-100um, and the distance from the pinhole 18 to the top end of a needle tip 20 is 40 um; the height of the microneedle is more than 500um, and the width of the microneedle is 200-420 um; the inclination angle of the needle surface 21 and the substrate 10 is 54.74 degrees; the invention sets the height of the micro-needle to be more than 500um, realizes that the uniformity of the diameter of the pinhole 18, the height of the needle point 20 and the width of the micro-needle is less than 2 percent, the inclination angle of the needle surface 21 and the base plate 10 is 54.74 degrees, and realizes that the needle point 20 can completely penetrate into the skin or reach the intradermal depth.

In this embodiment, the substrate 10 is a rectangular parallelepiped, the length of the substrate 10 is 2300um, the width is 900um, and the height is 300 um.

According to the invention, the groove 17 and the diversion trench 30 are arranged on the substrate 10, and the needle surface 21 is inclined towards the substrate 10 by a set angle, so that the mass production of the micro-needle can be realized, the good sharpness of the needle point 20 can be realized, and the technical problem that the micro-needle is difficult to penetrate into the skin or reach the intradermal depth can be solved; in addition, the invention has small structure size, high precision, simple flow, low cost and easy batch manufacture.

Example 2

This embodiment 2 provides a method for preparing a hollow microneedle array chip, including the following steps:

s01: providing a substrate 10, said substrate 10 comprising opposing front and back sides;

s02, forming a microneedle on the substrate 10, wherein the microneedle comprises a needlepoint 20, a pinhole 18 and a needle surface 21, and the needle surface 21 inclines towards the substrate 10 by a set angle;

s03, forming a groove 17 on the front surface of the substrate 10, wherein the groove 17 is formed on the periphery of the microneedle and comprises the microneedle in half;

and S04, forming a guide groove 30 on the back surface of the substrate 10 and communicating with the pinhole 18.

It should be noted that step S0N does not represent a sequential order.

Fig. 3 to 12 are schematic structural diagrams corresponding to the steps of embodiment 2. Referring to fig. 3 to 12, a method for manufacturing the hollow microneedle array chip will be described.

Referring to fig. 3, a substrate 10 is provided, the substrate 10 including opposing front and back sides.

The substrate 10 may be any suitable substrate material known to those skilled in the art, such as a semiconductor substrate material, e.g., silicon, germanium, silicon germanium, gallium arsenide, indium phosphide, etc., and in this embodiment, a monocrystalline silicon wafer with a crystalline phase <100> is used, the thickness of the silicon wafer is selected according to the height of the microneedles to be prepared, and the silicon wafer is cleaned by chemicals.

Referring to fig. 4, a guide groove 30 is formed on the rear surface of the substrate 10.

The forming method of the diversion trench 30 includes:

coating a layer of first photoresist 11 on the back surface of the substrate 10, and selectively exposing and developing the photoresist by using a pattern transfer technique in a conventional microelectronic process, so that a photoresist pattern is formed on the back surface of the substrate 10, as shown in fig. 4; the substrate 10 is etched using the photoresist as a mask film, so that the guiding trench 30 is formed on the back surface of the substrate 10. It should be noted that the photolithography and etching processes are well known to those skilled in the art, and are not described herein.

In this embodiment, the guiding groove 30 is circular or elliptical, the diameter of the guiding groove 30 is 100um, and the depth is 100-200 um; the guide groove 30 is arranged on the back of the substrate 10, and the guide groove 30 is communicated with a pinhole of a subsequently formed microneedle, so that the fixation and the sealing performance between the fluid pipe and the hollow microneedle array chip are improved by designing the guide groove 30 on the back of the substrate 10, and the flow rate of the fluid is improved by designing the guide groove 30.

After forming the flow guide grooves 30, the first photoresist 11 is removed.

The first photoresist 11 may be removed by a plasma process, or may be removed by a wet process, which is not limited herein.

Referring to fig. 5 to 12, after removing the first photoresist, forming a microneedle on the substrate 10, where the microneedle includes a needle tip 20, a needle hole 18, and a needle face 21, and the needle face 21 is inclined to the substrate 10 by a set angle; a groove 17 is formed on the front surface of the substrate 10, and the groove 17 is formed on the periphery of the microneedle and includes the microneedle.

The microneedle forming method comprises the following steps:

referring to fig. 5, a mask layer 12 is formed on the back surface of the substrate 10 through a deposition process, and a first groove 14 is formed by etching a portion of the mask layer 12.

The material SiO2 of the mask layer 12 is mainly used for etching the pinholes 18 of the microneedles later, and the deposition thickness of the SiO2 is determined according to the etching depth of the pinholes 18 of the microneedles.

The method of forming the first groove 14 includes:

referring to fig. 6, after forming a mask layer 12, a second photoresist 13 is coated on the mask layer 12, and a first groove 14 is formed through photolithography and etching processes.

In this embodiment, the first groove 14 penetrates through the mask layer 12.

The first groove 14 is used for subsequent formation of a pinhole of a microneedle.

The etching process may be dry etching or wet etching, and the dry etching process is adopted in this embodiment.

After the first groove 14 is formed, the second photoresist 13 is removed, and the method for removing the second photoresist 13 is referred to the foregoing description, and is not described herein again.

Referring to fig. 7 and 8, a second groove 16 and a trench 17 are formed on the front surface of the substrate 10 through photolithography and etching processes, and the second groove 16 and the first groove 14 are correspondingly disposed up and down.

After forming the first recess 14 and before forming the second recess 16 and the trench 17, further comprising,

forming a third photoresist 15 on the front surface of the substrate 10, and forming a second reserved groove 16a and a reserved groove 17a on the photoresist through a photolithography process;

the second recess 16 and the trench 17 are formed by an etching process, and then the third photoresist 15 is removed.

The groove 17 is the type of falling V, and the groove 17 is located the microneedle periphery of follow-up formation and the follow-up microneedle that forms of half parcel, the degree of depth of groove 17 is 30 ~ 80um, and the width is 50 ~ 100um, sets up groove 17 through the front at base plate 10, can help needle point 20 to pierce completely.

The photolithography process and the etching process are common knowledge of those skilled in the art, and are not described herein in detail; the method of removing the third photoresist 15 is described above.

Referring to fig. 9, the back surface of the substrate 10 is etched by a deep reactive ion etching process so that the first groove 14 and the second groove 16 communicate to form a pinhole 18.

The pinhole 18 is communicated with the diversion trench 30;

referring to fig. 10, after the pin holes 18 are formed, a protective layer 19 is formed, the protective layer 19 being formed on the front and rear surfaces of the substrate 10 and the inner walls of the pin holes 18.

The material of the protective layer 19 is Si3N4, which is used as the protective layer 19 for subsequent etching of the microneedle tip 20.

Referring to fig. 11 and 12, the tip 20 and the needle surface 21 are etched by a silicon anisotropic wet etching, and the needle surface 21 is inclined to the substrate 10 at a predetermined angle; the needle tip 20, the needle surface 21 and the needle hole 18 constitute the microneedle; the microneedles are diced into microneedle arrays by a dicing process.

Specifically, the diameter of a pinhole 18 of the microneedle is 10-100um, and the distance from the pinhole 18 to the top end of a needle tip 20 is 40 um; the height of the microneedle is more than 500um, and the width of the microneedle is 200-420 um; the inclination angle of the needle surface 21 and the substrate 10 is 54.74 degrees; the invention sets the height of the micro-needle to be more than 500um, realizes that the uniformity of the diameter of the pinhole 18, the height of the needle point 20 and the width of the micro-needle is less than 2 percent, the inclination angle of the needle surface 21 and the base plate 10 is 54.74 degrees, and realizes that the needle point 20 can completely penetrate into the skin or reach the intradermal depth.

After the formation of the protective layer 19 and before the formation of the needle tip 20 and the needle face 21, the method further includes,

removing the protective layer 19 on the front surface of the substrate 10, and reserving the protective layer 19 on the back surface of the substrate 10 and on the inner wall of the pinhole 18;

after the needle tip 20 and the needle face 21 are formed, the protective layer 19 is removed.

Specifically, the inclination of the etched needle surface is 54.74 degrees by using different etching rates of KOH to each crystal surface of silicon, and the height of the micro needle is determined according to the KOH etching time; the needle tip 20 is etched by utilizing the corrosiveness of HF on the Si3N4 protection layer 19, and the remaining Si3N4 protection layer 19 such as the inner wall of the pinhole 18 of the microneedle and the inside of the groove 17 is removed.

With continued reference to fig. 12, after removing the protective layer 19, a protective film 31 is deposited on the front and back surfaces of the substrate 10 and the inner walls of the pinholes 18 by a high temperature process.

Specifically, the material of the protective film 31 is SiO 2; the SiO2 is deposited by Low Pressure Chemical Vapor Deposition (LPCVD) or high temperature furnace tube thermal oxidation SiO 2; in addition, the sharpness of the tip 20 may be increased by high temperature, and the hardness of the tip 20 may be increased by sputtering metal on the surface.

It should be noted that the present invention accomplishes the whole manufacturing process by adopting the MEMS process technology.

According to the invention, the flow guide groove 30 is formed on the back surface of the substrate 10, and the groove 17 and the micro-needle are formed on the front surface of the substrate 10, so that the process flow for manufacturing the hollow micro-needle is simplified, the mass production is realized, and the production cost is reduced.

Furthermore, the invention adopts MEMS technology, the diversion trench 30, the trench 17 and the pinhole 18 are manufactured by photoetching and etching processes, then the height of the microneedle is higher than 500um by wet etching, the inclination angle of the needle surface 21 and the substrate 10 is 54.74 degrees, and the needle point 20 can completely penetrate into the skin or reach the intradermal depth.

It should be noted that, in the present specification, all the embodiments are described in a related manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments.

The above description is only for the purpose of describing the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention, and any variations and modifications made by those skilled in the art based on the above disclosure are within the scope of the appended claims.