Processing method of nano microneedle
By combining photolithography and reactive ion etching processes with automated detection and control, the problem of precise control of nanoneedles has been solved, achieving high-quality and consistent production, broadening the selection of materials, and enhancing the application potential of nanoneedles.
Patent Information
- Application Number
- CN202511843340.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-09
- Publication Date
- 2026-02-13
AI Technical Summary
The size, morphology, arrangement, and surface nanostructure of existing nanoneedles are difficult to precisely control, resulting in limitations in overall specifications and restricting their widespread application.
By combining photolithography and reactive ion etching processes with fully automated processes such as visual dispensing, visual recognition mounting, and online inspection, the three-dimensional morphology and surface nanostructure of microneedles can be precisely controlled, expanding the range of material choices.
It has enabled precise control and consistent production of microneedle structures, improved product quality and market competitiveness, broadened material selection, reduced human error, and increased production efficiency and stability.
Smart Images
Figure CN121513337A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of nanometer microneedle, and particularly relates to a processing method of nanometer microneedle. BACKGROUND
[0002] The nanometer microneedle is a leading minimally invasive transdermal drug delivery technology, and the core of the technology is that a micrometer array type small needle tip can painlessly penetrate the stratum corneum barrier of the outermost layer of the skin and does not touch the deep nerve and blood vessel, thereby forming a temporary micro channel on the surface of the skin. The channel is like an 'efficient bridge', which can accurately deliver drugs, vaccines, cosmetic active ingredients or diagnostic molecules to the epidermis or superficial dermis layer, greatly improving the transdermal efficiency and bioavailability of the drugs. Compared with traditional injection, the technology significantly reduces pain and fear, and avoids the first-pass effect; compared with traditional external preparation, the technology successfully breaks through the limitation of the skin barrier. At present, the nanometer microneedle technology has been widely applied in many fields such as vaccine immunization, diabetes management, medical beauty anti-aging, skin disease treatment and biological signal monitoring.
[0003] The nanometer microneedles produced in the prior art have many problems that are difficult to solve, and the most significant problem is that the size, shape and arrangement of the microneedles cannot be accurately controlled. Specifically, the heights of the microneedles are uneven, some of which are too high and some of which are too low, the diameters of the bottoms of the microneedles are different, some of which are thick and some of which are thin, and the taper angles of the microneedles are different. Moreover, the spacing of the microneedles is disordered and has no regularity. In addition, the nanometer structures on the surface of the microneedles also have many defects, the shapes of the nanometer structures are unclear, the depths of the nanometer structures are different, and the positions of the nanometer structures are randomly distributed without specific rules or patterns. Due to the influence of these factors, the overall specifications of the nanometer microneedles are limited in a very narrow range, which greatly limits the wide application of the nanometer microneedles in various fields. SUMMARY
[0004] The present application aims to provide a processing method of nanometer microneedle to solve the problems in the prior art.
[0005] To achieve the above object, the present application provides the following technical scheme: a processing method of nanometer microneedle, comprising the following steps: Step one: preparing a plastic part, a single crystal silicon or a gold wafer, and UV glue; Step two: cleaning the surface of the single crystal silicon or the gold wafer, coating photoresist on the surface and drying, transferring the microneedle array pattern to the photoresist layer by a photoetching process, using positive photoresist, the chemical structure of the exposed area changes, the solubility increases, and the exposed area is dissolved and removed during development, and the unexposed part is retained; Step three: Put the wafer into a vacuum reaction chamber, introduce reaction gas, apply RF power to generate plasma, and perform anisotropic etching on the wafer to form a microneedle cylinder; Step four: Remove the residual photoresist and clean to obtain a microneedle array; Step five: Apply UV glue to the predetermined position of the plastic part; Step six: Assemble the microneedle array to the glue position of the plastic part; Step seven: UV irradiation is performed on the assembled product to cure the UV glue; Step eight: Appearance inspection and packaging are performed on the cured product.
[0006] Preferably, the surface cleaning in step two adopts RCA standard cleaning method. First, SC-1 solution is used to remove organic contaminants and part of metal ions through oxidation and complexation; then SC-2 solution is used to dissolve alkali metal ions and residual metal impurities. The cleaning process is mild and effective, and can effectively obtain a clean and hydrophilic silicon surface. The reaction gas introduced in step three is SF6 or CF4. An isotropic etchant is used during the etching process in step three, and the isotropic etchant is a mixture of HF, HNO3 and CH3COOH.
[0007] Preferably, the step five further includes electrostatic elimination treatment of the plastic part, and an ion fan is used to eliminate static electricity.
[0008] Preferably, the step five uses a full-automatic visual glue dispensing machine to dispense glue, and a visual system is used to identify the position of the plastic part to realize quantitative glue dispensing.
[0009] Preferably, the step five further includes online detection of the glue dispensing effect, and the detection content includes glue amount, glue dispensing position, stringing or air bubble.
[0010] Preferably, the step six uses a pick-and-place machine to pick up the microneedle array through a visual recognition system and assemble it to the glue dispensing position of the plastic part.
[0011] Preferably, the step six further includes semi-finished product inspection, and the inspection content includes whether the microneedle array is shifted or inverted, whether the glue dispensing position forms complete encapsulation, and whether there is glue overflow pollution.
[0012] Preferably, the step seven uses a UV curing line to cure, and uniform curing is realized by controlling the intensity of the UV light source and the conveying speed.
[0013] Preferably, the finished product inspection in step eight includes checking the assembly position accuracy, glue overflow, floating phenomenon and product cleanliness under a microscope.
[0014] Preferably, the packaging in step eight adopts an anti-static packaging material, and the packaging bag is sealed and a label containing information of material name, specification, quantity and production date is pasted.
[0015] Compared with the prior art, the application has the following advantages: 1. In the present application, through the close combination of photolithography and reactive ion etching process, and the accurate regulation of mask design and etching parameters, the accurate control of the three-dimensional morphology of microneedles and the surface nanostructure can be realized, various structures from vertical columns to sharp cones can be prepared, and the design flexibility is high. The core etching process is not only suitable for the most commonly used single crystal silicon, but also can be extended to titanium, stainless steel and other metal materials, and even some special polymers by adjusting the etching gas and process parameters, thereby widening the material selection range of nano microneedles.
[0016] 2. In the present application, automatic visual dispensing, visual recognition and mounting, online detection and pipeline curing and other automatic processes are introduced, which greatly reduces the human operation error, improves the production efficiency and process stability, ensures the high consistency between batches of products, embeds multiple inspection nodes in the whole process flow, adopts a standardized packaging and label system, establishes a complete quality control and product traceability system, and improves the reliability and market competitiveness of the products. BRIEF DESCRIPTION OF DRAWINGS
[0017] Figure 1 The figure is a nanometer microneedle processing flowchart of the present application. DETAILED DESCRIPTION
[0018] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.
[0019] As Figure 1As shown, the application provides a technical solution of a nano-microneedle processing method, including the following steps: preparing a plastic part, a single crystal silicon or a gold wafer, and a UV glue; removing the surface contaminants, particles and natural oxide layer of the single crystal silicon by chemical cleaning method to obtain an atomically clean surface, uniformly spin coating a layer of photoresist on the surface of the silicon wafer, and drying, tightly aligning or projecting the photo mask designed with a microneedle array pattern onto the glued silicon wafer, and using 365nm ultraviolet light for irradiation. The photoresist in the light irradiation area undergoes photochemical reaction, the exposed silicon wafer is immersed in a specific chemical developing solution, and the soluble part of the photoresist is dissolved, so that the two-dimensional planar pattern on the mask is accurately copied to the photoresist layer, and the silicon area below which needs to be etched is exposed; place the silicon wafer in a vacuum reaction chamber, then introduce reaction gas into the chamber, and then apply radio frequency power to promote the reaction gas to generate plasma. In the plasma, there are a large number of high-energy ions, which will vertically bombard the surface of the silicon wafer. At the same time, the active radicals in the plasma will also chemically react with silicon elements, thereby generating volatile products. This way of physical and chemical interaction working together has a high anisotropy characteristic, and can realize vertical etching operation, thereby forming a microneedle column structure with high aspect ratio and very steep sidewall. Then, a strong oxidizing agent solution or oxygen plasma is used to completely remove the remaining photoresist. Finally, a cleaning process is performed again, so that a pure and impurity-free silicon microneedle array is obtained.
[0020] Specifically, by closely cooperating the photolithography technology with the reactive ion etching process, and precisely controlling the design of the mask and the etching parameters, the precise control of the three-dimensional morphology and surface nanostructure of the microneedle can be achieved. In this way, various structural forms can be prepared, such as from the regular shape of vertical column to the more special structure of sharp cone, which has very high flexibility in design. The core etching process is not only suitable for single crystal silicon which is the most common material in practical application, but also can be further extended to metal materials such as titanium and stainless steel by adjusting the etching gas and process parameters, and even applicable to some special polymers, thereby greatly widening the range of nano-microneedle material selection.
[0021] For example, Figure 1As shown, the plastic parts placed in the dispensing jig need to undergo an electrostatic elimination step, which is very important because static electricity can affect the quality of subsequent processing. Specifically, the plastic parts are subjected to comprehensive electrostatic elimination treatment by ionizing fans to ensure that their surfaces are not attracted to dust or other tiny particles due to static electricity. During the dispensing process, the operator needs to inject UV glue into the needle cylinder of the dispensing machine to ensure sufficient glue supply and no air bubbles are left. Then start the full-automatic visual dispensing machine, which uses advanced vision systems to identify the precise position of the plastic parts in the jig to ensure the accuracy of dispensing. According to the preset program, the device will dispense a certain amount of glue at the predetermined position of the plastic part, which requires high stability and consistency. In addition, the dispensing step also includes online detection of dispensing effect, which covers multiple aspects, such as whether the glue amount meets the standard, whether the dispensing position is accurate, and whether there are stringing or bubble problems, which will directly affect the final quality of the product.
[0022] During the patching process, the wafer is first placed on the feeder of the patching machine to facilitate subsequent operations. The patching machine picks up the wafer with a suction nozzle and moves it under the vision camera for high-precision identification and positioning. In order to improve the accuracy of identification, the operator adjusts the identification threshold to ensure that the wafer can be accurately identified and positioned. After confirmation, the patching machine assembles the wafer to the dispensing position of the plastic part, completing this critical step. After patching is completed, a semi-finished product inspection step must be performed to further ensure product quality. The inspection includes: whether the wafer is offset or inverted, whether the dispensing position forms a complete encapsulation structure, and whether there is glue overflow contaminating the wafer pins. These inspection items are crucial to avoid potential problems in subsequent processes.
[0023] Next is the curing process, which is completed using an efficient UV curing pipeline. By precisely controlling the intensity of the UV light source and the conveying speed of the pipeline, it can be ensured that the UV glue is completely cured within the appropriate time, thereby achieving the desired bonding effect. After curing is completed, the finished product inspection step is entered. Finished product inspection is strict and usually requires careful examination of multiple details under a microscope, including whether the wafer patching position meets the accuracy standard, whether there is glue overflow on the product surface, whether there is a floating problem, and whether the overall cleanliness of the product meets the standard. Only products that pass all inspections can be considered as qualified products.
[0024] Finally, during the packaging process, anti-static packaging materials are used to prevent static electricity from damaging the product. At the same time, the packaging bag is sealed to ensure that the product is not affected by the external environment during transportation and storage. In addition, labels containing detailed information such as material name, specification, quantity, and production date are attached to facilitate subsequent management and traceability. The entire process is closely linked, and each step is carefully designed and strictly controlled to ensure that the final delivered product has high quality and high reliability.
[0025] Specifically, ion fans are used to eliminate static electricity on plastic parts, which can effectively prevent the adsorption of contaminants due to static electricity, thereby preventing these contaminants from having adverse effects on subsequent process flows, thereby ensuring the cleanliness and quality stability of the product. The use of a fully automatic visual dispensing machine can achieve very precise positioning and quantitative dispensing operations. In this process, online detection functions are also combined, which greatly improves the automation level of production, reduces errors caused by human factors, and can timely intercept defective products. The placement machine uses visual recognition technology and adjusts the threshold according to actual conditions to achieve precise placement of the silicon microneedle array. Unqualified products can be screened out in the semi-finished product inspection link, thereby reducing the cost investment in the subsequent production process. The UV curing line precisely controls the intensity of the light source and the running speed of the conveyor belt to ensure uniform curing effects, which not only improves production efficiency but also improves product consistency. The product is detected from multiple dimensions under a microscope to ensure that the final product meets high-quality standard requirements. The product is sealed and packaged using anti-static materials, which can prevent the product from being damaged during storage or transportation. The label contains complete material information, which is very convenient for warehouse management and quality traceability when needed.
[0026] It will be obvious to a person skilled in the art that, without departing from the spirit or essential characteristics of the application, the present application can be implemented in other specific forms. The present application is therefore considered in all its symmetrical and / or asymmetric forms to be encompassed in the principle and scope of the appended claims, and all changes that come within the meaning and range of equivalents are intended to be embraced therein. Any reference signs in the claims should not be construed as limiting the claims.
Claims
1. A method for fabricating nanoneedles, characterized in that, Includes the following steps: Step 1: Prepare plastic parts, monocrystalline silicon or gold wafers, and UV adhesive; Step 2: Clean the surface of the single-crystal silicon or gold wafer, coat it with photoresist and dry it, and transfer the microneedle array pattern to the photoresist layer through photolithography. Step 3: Place the wafer in a vacuum reaction chamber, introduce the reaction gas, apply radio frequency power to generate plasma, and perform anisotropic etching on the wafer to form microneedle pillars; Step 4: Remove residual photoresist and clean to obtain a microneedle array; Step 5: Apply UV adhesive to the designated locations on the plastic parts; Step Six: Mount the microneedle array onto the dispensing position of the plastic part; Step 7: Expose the mounted product to UV light to cure the UV adhesive; Step 8: Inspect the appearance of the cured product and package it.
2. The method for fabricating nanoneedles according to claim 1, characterized in that: The surface cleaning in step two adopts the RCA standard cleaning method. The reaction gas introduced in step three is SF6 or CF4. The etching process in step three uses an isotropic etchant, which is a mixture of HF, HNO3 and CH3COOH.
3. The method for fabricating nanoneedles according to claim 1, characterized in that: Before step five, the process also includes static electricity elimination treatment of the plastic parts, using an ion fan to eliminate static electricity.
4. The method for fabricating nanoneedles according to claim 1, characterized in that: In step five, a fully automatic vision dispensing machine is used for dispensing, and the position of the plastic part is identified by the vision system to achieve quantitative dispensing.
5. The method for fabricating nanoneedles according to claim 1, characterized in that: Step five also includes online detection of the dispensing effect, including the amount of glue, dispensing location, and whether there are strings or bubbles.
6. The method for fabricating nanoneedles according to claim 1, characterized in that: In step six, a pick-and-place machine is used to pick up the microneedle array through a vision recognition system and attach it to the dispensing position of the plastic part.
7. The method for fabricating nanoneedles according to claim 1, characterized in that: Step six is followed by semi-finished product inspection, which includes checking whether the microneedle array is offset or inverted, whether the dispensing position forms a complete coating, and whether there is any overflow contamination.
8. The method for fabricating nanoneedles according to claim 1, characterized in that: In step seven, a UV curing production line is used for curing, and uniform curing is achieved by controlling the intensity of the UV light source and the conveying speed.
9. The method for fabricating nanoneedles according to claim 1, characterized in that: The finished product inspection in step eight includes checking the accuracy of the mounting position, the amount of adhesive overflow, the floating phenomenon, and the cleanliness of the product under a microscope.
10. The method for fabricating nanoneedles according to claim 1, characterized in that: In step eight, the packaging uses anti-static packaging materials, the packaging bag is sealed, and a label containing the material name, specifications, quantity, and production date information is affixed.