A method of preparing a model

Abstract

The application provides a preparation method of a model, comprising the following steps: chemically modifying a silicon-based substrate by using a siloxane compound containing a double bond to obtain a chemically modified silicon-based substrate; fixing the chemically modified silicon-based substrate on a metal platform, performing 3D printing according to a pre-constructed model, and forming the model on the chemically modified silicon-based substrate; and separating the silicon-based substrate on which the model is formed from the metal platform of the 3D printer. The siloxane compound containing a double bond is used to chemically modify the silicon-based substrate, so that the adhesion between the model and the silicon-based substrate is improved, and thus a small model with a size of 10 microns can be printed on the smooth silicon-based substrate. Moreover, the preparation of the model is directly performed on the silicon-based substrate, and a silicon-based chip or a micro-fluidic chip can be directly obtained. On the other hand, the model can be separated from the silicon-based substrate by using an acid liquid treatment, and the model, especially the small model, is not damaged.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of 3D printing technology, in particular to a model preparation method. BACKGROUND

[0002] 3D printing technology, also known as additive manufacturing technology, is a kind of rapid prototyping technology, which is based on digital model file and constructs three-dimensional objects through point-by-point or layer-by-layer printing. Compared with traditional manufacturing, 3D printing technology does not need mold manufacturing or mechanical processing, and avoids the waste of materials and energy in traditional subtractive manufacturing process. Based on the 3D printing of initiation solidification, it occupies the absolute dominant position of new 3D printing method, and has the unique advantage in the preparation of high-precision structure. The solidification of the curable liquid as ink can make the structure to be printed grow out of the liquid material, thereby opening up new sensor technology, new drug delivery technology and new chip laboratory application.

[0003] Stereolithography technology is a kind of 3D printing technology based on light-induced solidification. A computer controls a laser beam, and the design data provided by a computer-aided design (CAD) system is used to solidify liquid photopolymer resin layer by layer with ultraviolet light. The plane movement of the light source is combined with the vertical movement of the platform to manufacture three-dimensional objects. Stereolithography technology has the advantages of high precision, short time consumption, no need of tools in the forming process, no need of personnel intervention, and high integration of design and manufacturing.

[0004] The existing stereolithography 3D printing is usually carried out on a metal platform. In order to ensure that the printed model adheres to the platform without falling off, the platform usually needs to have a certain roughness to increase the contact area between the photopolymer resin and the platform, thereby improving the adhesion between them. After printing is completed, the model usually needs to be taken down with a blade or other tools, which may cause damage to the model, especially to small models. SUMMARY

[0005] Therefore, the present application provides a model preparation method. The method provided by the present application does not need to use a blade or other tools to take down the model, and will not cause damage to the model, especially to small models.

[0006] In the existing stereolithography 3D printing technology, in order to ensure the close combination of the model and the platform, it is usually necessary to carry out the printing on a platform with a certain roughness. If the stereolithography 3D printing is carried out on a smooth and smooth silicon substrate, the van der Waals force between the non-polar silicon substrate and the polar resin is weak, and the contact area between the resin and the substrate on the smooth surface is small, resulting in poor adhesion between the model formed by the resin and the substrate. Especially, small models are easy to fall off during printing or cleaning.

[0007] Based on this, the application provides a preparation method of a model, comprising the following steps:

[0008] a) chemically modifying a silicon-based substrate by using a siloxane compound containing a double bond to obtain a chemically modified silicon-based substrate;

[0009] b) fixing the chemically modified silicon-based substrate on a metal platform of a 3D printer, and performing 3D printing according to a pre-constructed model to form a model on the chemically modified silicon-based substrate;

[0010] c) separating the silicon-based substrate on which the model is formed from the metal platform of the 3D printer.

[0011] The application chemically modifies a silicon-based substrate by using a siloxane compound containing a double bond, thereby improving the adhesion of the model to the silicon-based substrate, so that a small model with a size of 10 μm can be printed on a flat and smooth silicon-based substrate. Moreover, the application directly prepares a model on a silicon-based substrate, so that a silicon-based chip or a microfluidic chip can be directly obtained. On the other hand, the application can separate the model from the silicon-based substrate by using an acid solution, without damaging the model, especially a small model.

[0012] The application uses a stereolithography 3D printer to prepare a model, for example, a Mofang Precision S230 micro-stereolithography precision printing system. The application does not have special restrictions on the photocurable resin used for the 3D printing, and resins containing unsaturated double bonds such as polyurethane acrylate, epoxy acrylate resin and polyester acrylate resin can be used, and polyurethane acrylate is preferred. The application does not have special restrictions on the metal platform used for the 3D printing, and a metal platform matched with the printer can be used.

[0013] The application uses a chemically modified silicon-based substrate as a carrier to print a model. Specifically, the application first cuts the silicon-based substrate into appropriate sizes, and the minimum size needs to have enough space for the laser to measure the distance at four corners, for example, to cover the four laser ranging points of the metal platform of the stereolithography 3D printer, so as to ensure the successful leveling of the surface of the silicon-based substrate, and the maximum size is approximately equal to the size of the metal platform. For example, when a Mofang Precision S230 micro-stereolithography precision printing system is used, the minimum size of the silicon-based substrate is about 1*1 cm, and the maximum size is about 6*6 cm. In some specific implementations, the silicon-based substrate is a substrate mainly composed of silicon or a compound containing silicon, including but not limited to quartz, glass, silicon wafer or silicon dioxide ceramic, and preferably quartz, glass or silicon wafer.

[0014] After obtaining a silicon-based substrate with a suitable size, the silicon-based substrate is chemically modified. Specifically, the silicon-based substrate can be chemically modified according to the following method:

[0015] a1) pretreating the silicon-based substrate;

[0016] a2) after the plasma treatment of the pretreated silicon-based substrate, chemically modifying the silicon-based substrate with a siloxane compound containing double bonds to obtain a chemically modified silicon-based substrate.

[0017] The present application first pretreats the silicon-based substrate to improve the binding ability of the siloxane compound containing double bonds to the silicon-based substrate. Specifically, the pretreatment includes the following steps:

[0018] The silicon-based substrate is cleaned in acetone, anhydrous ethanol and water, respectively, and then treated in the cleaning solution to obtain a pretreated silicon-based substrate after water washing.

[0019] The cleaning solution includes concentrated sulfuric acid, hydrogen peroxide and water.

[0020] The silicon-based substrate is cleaned in acetone, anhydrous ethanol and water, respectively, and preferably ultrasonic cleaning, and the cleaning time is preferably 3-10 minutes. The water is preferably deionized water, and then the surface is preferably cleaned with deionized water. The cleaning solution includes concentrated sulfuric acid, hydrogen peroxide and water. In some specific embodiments, the cleaning solution includes a concentrated sulfuric acid and hydrogen peroxide solution with a volume ratio of 50-70:30-50, preferably 70:30; the concentration of the concentrated sulfuric acid is more than 90%, preferably 98%; the concentration of the hydrogen peroxide solution is 20wt%-40wt%, preferably 30%. The treatment temperature is preferably 100-150°C, more preferably 120-140°C, and the treatment time is preferably 1-2h, more preferably 1.5h. After the treatment in the cleaning solution, the silicon-based substrate is washed, preferably with deionized water until no acid solution is left.

[0021] Since the upper surface of the silicon-based substrate needs to be determined as the initial plane for printing in the 3D printing process, and the upper surface of the transparent substrate (such as quartz, glass) cannot be accurately focused, it is necessary to construct an opaque area on the surface for focusing. The present application uses vacuum evaporation method to deposit a 10-20nm metal chromium layer on a corner of the cleaned transparent silicon-based substrate surface. In some specific embodiments, the area of the metal chromium layer is about 3*3mm.

[0022] After the silicon-based substrate is pretreated, it is treated in a plasma, preferably in an oxygen plasma, to produce functional groups such as hydroxyl groups on the surface of the silicon-based substrate. In some specific implementations, the treatment is preferably for 3-8 minutes, more preferably for 5 minutes, and then chemical modification is performed using a siloxane compound containing a double bond. Specifically, the silicon-based substrate after plasma treatment can be immersed in a solution of a siloxane compound containing a double bond for treatment, the chemical formula of the siloxane compound containing a double bond can be Y-Si(OR)3, wherein Y is an organic functional group containing a double bond, R is an alkyl group, etc., the silanol group is reactive to inorganic substances, the organic functional group is reactive or compatible to organic substances, therefore, the siloxane compound containing a double bond can form a combined layer of organic matrix-silane coupling agent-inorganic matrix between the inorganic and organic interfaces. In some specific implementations, the siloxane compound containing a double bond includes but is not limited to one or more of γ-methacryloxypropyltrimethoxysilane (silane coupling agent KH-570, chemical formula CH2=C(CH3)COO(CH2)3Si(OCH3)3), vinyltrimethoxysilane (A-171, chemical formula CH2=CHSi(OCH3)3), vinyltris(β-methoxyethoxy)silane (A-172, chemical formula CH2=CHSi(OCH2CH2OCH3)3), or vinyltriethoxysilane (A-151, chemical formula CH2=CHSi(OC2H5)3), preferably silane coupling agent KH-570. The solvent of the solution of the siloxane compound containing a double bond is not particularly limited in the present application, as long as the siloxane compound containing a double bond can be dissolved to form a solution, for example, toluene. The temperature of the immersion is not particularly limited in the present application, and room temperature is sufficient. The time of the immersion is not particularly limited in the present application, and is preferably 10-20 hours, more preferably 12 hours.

[0023] The principle of chemical modification of the silicon-based substrate by silane coupling agent KH570 is shown in Figure 1 Figure 1 The principle of chemical modification of the silicon-based substrate in the present application is shown in the following figure:

[0024] The surface of the silicon-based substrate treated by oxygen plasma has a large number of -OH (hydroxyl groups), in which the O (oxygen) atom performs nucleophilic substitution on the Si (silicon) atom in the coupling agent, and finally forms a SiO2 (Si)-O-Si bond, realizing the modification of the carbon-carbon double bond on the surface of the substrate.

[0025] ​After the modification of the silicon-based substrate is completed, the silicon-based substrate is fixed on the metal platform of the 3D printer, and the application preferably uses a light-cured resin to fix the silicon-based substrate on the metal platform. Specifically, for a transparent silicon-based substrate, first, a light-cured resin is added dropwise on the metal platform, and then the silicon-based substrate is placed on the light-cured resin to allow the light-cured resin to fill the gap between the silicon-based substrate and the metal platform. Then, use a UV flashlight to irradiate for about 5 seconds to cure the light-cured resin in the gap and fix the silicon-based substrate. For an opaque silicon-based substrate, the silicon-based substrate can be placed on the metal platform first, and then the light-cured resin is added dropwise evenly along the edge of the silicon-based substrate, and then the UV flashlight is used to irradiate for about 5 minutes.

[0026] After the modified silicon-based substrate is fixed on the metal platform, the four corners of the silicon-based substrate are preferably laser-ranged and leveled, and the upper surface of the silicon-based substrate is determined as the initial plane for printing by focusing with UV light, and then 3D printing is performed. As described above, the application has no special restrictions on the parameters of the 3D printing, which can be adjusted according to the model to be printed.

[0027] The light-cured resin used in 3D printing contains photoinitiators, resin monomers / oligomers, adhesives, etc. The photoinitiator can absorb light of a specific wavelength and produce active free radicals. Active free radicals can combine with monomers / oligomers and activate them, and cross-link and solidify with other monomers / oligomers, changing from a liquid state to a solid state. In stereolithography 3D printing, the bonding force between the model and the substrate is mainly weak intermolecular force, and strong chemical bonds can enhance the bonding force. The light-cured resin monomer usually contains unsaturated double bonds, which will be activated under the action of active free radicals and undergo coupling reactions with the double bonds of other resin monomers. The application modifies the carbon-carbon double bonds on the surface of the silicon-based substrate. When the light-cured resin on the substrate surface is irradiated with UV light, the double bonds on the substrate surface participate in the reaction and couple with the double bonds in the resin monomer, so the bonding force between the model and the substrate changes from weak intermolecular force to strong chemical bonds, achieving the effect of enhancing the adhesion of the model and the substrate. Taking polyurethane acrylate resin as an example, the mechanism of coupling between light-cured resin and quartz during light curing is shown in Figure 2 Figure 2 ​The mechanism of coupling of the photocured resin and the quartz is shown in the figure. The photoinitiator R in the photocured resin absorbs energy under the irradiation of a light source of a certain wavelength to undergo photolysis reaction and generate free radicals. The reaction process is shown in formula (1). The free radicals can activate the polyurethane acrylate monomers and oligomers (in the subsequent steps, the monomers are replaced by the letter M). The activated monomers and oligomers initiate the polymerization of the active monomers and oligomers, as shown in formula (2). The active monomers and oligomers are coupled with the carbon-carbon double bonds on the surface of the substrate and crosslinked with other monomers and oligomers to form a polymer with the photoinitiator, one end of which is coupled with the surface of the substrate, as shown in formula (3). When another polymer with the photoinitiator is encountered, the polymerization reaction is terminated to form a high molecular polymer coupled with the substrate, as shown in formula (4).

[0028] After printing, the obtained model is attached to the silicon substrate, and the silicon substrate is separated from the metal platform to obtain a silicon substrate integrated with the model, which can be directly used as a silicon chip. In some specific implementations, a blade can be used to separate the silicon substrate from the metal platform without damaging the model. After separating the silicon substrate, the silicon substrate is preferably rinsed with ethanol, then soaked in DMF (N-N' dimethylformamide) for 3-5 seconds to remove the residual uncured resin, and finally rinsed with ethanol and blown dry.

[0029] The application can also use the method of soaking the silicon substrate integrated with the model in an acid solution to separate the model from the silicon substrate without damage. Specifically, the application can soak the silicon substrate integrated with the model in a hydrofluoric acid solution to separate the model from the silicon substrate. In some specific implementations, the concentration of the hydrofluoric acid is preferably 5% to 15%, more preferably 10%. In some specific implementations, the soaking is preferably carried out under ultrasonic, the power of the ultrasonic is preferably 10W to 50W, more preferably 10W to 30W, most preferably 10W to 20W, and the soaking time is preferably 20s to 90s, more preferably 30s to 60s. After soaking, the model is obtained by filtering and cleaning with a stainless steel screen.

[0030] The method provided by the application can be used to prepare a model or a micro-channel chip by 3D printing. The size of the model is not limited and can be as low as 10μm, for example, 10μm to 100μm, etc.

[0031] This application couples the printed model with a smooth silicon-based substrate through a siloxane compound containing double bonds, changing the bonding force between the model and the substrate from a weak physical adsorption force to a strong chemical bond, thus achieving 3D printing of micro-models on a smooth silicon-based substrate and enabling direct integration of micro-components. Compared with unmodified silicon-based substrates, the method provided by this application can reduce the model size to 20μm ~ 30μm, or even 10μm ~ 20μm, which is smaller than the size of the model printed directly on the metal platform of the printer. Moreover, this application uses acid immersion to separate the model from the silicon-based substrate, without the need for tools such as blades, and will not cause damage to the model. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Schematic diagram of the principle of chemical modification of silicon-based substrates in this application;

[0033] Figure 2 Schematic diagram of the coupling mechanism between photocurable resin and quartz;

[0034] Figure 3 A photograph of the printed silicon wafer provided in Example 1;

[0035] Figure 4 A microscope image of the micro-model on the silicon wafer after printing provided in Example 1;

[0036] Figure 5 A microscope photo of the printed quartz plate provided in Example 2;

[0037] Figure 6 This is a microscopic photograph of the model after shedding provided in Example 2;

[0038] Figure 7 A microscopic photograph of the printed silicon wafer provided in Example 3;

[0039] Figure 8 A microscope photograph of the printed quartz plate provided in Example 4;

[0040] Figure 9 A microscope photograph of the printed metal platform provided for Comparative Example 1;

[0041] Figure 10 A microscope photograph of the printed silicon wafer provided for Comparative Example 2;

[0042] Figure 11 This is a microscope photo of the printed quartz plate provided for Comparative Example 3. DETAILED DESCRIPTION

[0043] It should be understood that the expression "one or more of" includes individually each of the objects recited after the expression and various combinations of two or more of the recited objects, unless otherwise understood from the context and usage. The expression "and / or" in connection with three or more recited objects should be understood to have the same meaning, unless otherwise understood from the context.

[0044] The use of the terms "including," "comprising," or "having" and variations thereof, as used in this document, are intended to be open and permissive, and thus do not exclude additional, unrecited elements or steps. The terms "substantially," "essentially," "approximately," "about," and variations thereof, are intended to describe the value as being close to the stated value within a reasonable range, unless otherwise stated or understood from the context.

[0045] It should be understood that the order of steps or order for performing certain actions is immaterial so long as the application remains operable. Moreover, two or more steps or actions can be conducted simultaneously.

[0046] The use of any and all examples, or exemplary language herein, is intended merely to better illuminate the application and does not pose a limitation on the scope of the application unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the application.

[0047] Further, the numerical ranges and parameters setting forth the broadest scope of the application are approximations, and are merely intended to convey general information as to the scope of the application. Consistent with the application as claimed, the numerical ranges and parameters should be construed in light of the number of requests for claims. Therefore, unless otherwise stated, it is intended that all ranges and parameters, whether numerical or otherwise, recited in this document are "about" modified. Here, "about" generally means within 10%, 5%, 1%, or 0.5% of a particular value or range.

[0048] The present application provides a method for preparing a model, comprising the following steps:

[0049] a) chemically modifying a silicon-based substrate with a siloxane compound containing a double bond to obtain a chemically modified silicon-based substrate;

[0050] b) fixing the chemically modified silicon-based substrate on a metal platform of a 3D printer, and 3D printing according to a pre-constructed model to form a model on the chemically modified silicon-based substrate;

[0051] c) separating the silicon-based substrate with the model formed thereon from the metal platform of the 3D printer.

[0052] The application adopts a siloxane compound containing a double bond to chemically modify a silicon-based substrate, improves the adhesion of the model to the silicon-based substrate, and thus can print a small model with a size of 10 μm on a flat and smooth silicon-based substrate. Moreover, the application directly prepares the model on the silicon-based substrate, and can directly obtain a silicon-based chip or a micro-fluidic chip. On the other hand, the application can separate the model from the silicon-based substrate by using an acid liquid treatment, and will not cause damage to the model, especially a small model.

[0053] The application will be further described below in combination with examples. The protection scope of the application is not limited by the following examples.

[0054] In the following examples, the photocurable resin is HTL resin produced by Shenzhen Mofan Material Technology Co., Ltd., and the main components of the HTL resin are polyurethane acrylate, 2-methyl-1,8-neopentyl glycol diacrylate, (2,4,6-trimethylbenzoyl) diphenyl phosphine oxide, 4-acryloyl morpholine and tris (2-acryloyloxyethyl) isocyanurate.

[0055] Example 1

[0056] The silicon wafer is cut into a size of about 3*4 cm, and then is ultrasonically cleaned with acetone, anhydrous ethanol and deionized water for 5 min. Then the silicon wafer is cleaned with deionized water, and then is placed into a cleaning solution (a mixed solution of 98% concentrated sulfuric acid and 30% hydrogen peroxide, and the volume ratio of the two is 7:3) and heated at 140°C for 1 h. Then the silicon wafer is cleaned with deionized water until no acid solution is left.

[0057] 500 μL of silane coupling agent KH-570 is taken by a pipette and added into 100 mL of toluene to prepare a coupling agent solution. The cleaned silicon wafer is treated by oxygen plasma for 5 min, and then is soaked in the coupling agent solution for 12 h to obtain a modified silicon wafer. The modified silicon wafer is cleaned with ethanol and then is blown dry.

[0058] The modified silicon wafer is placed on a printing platform, and some photocurable resin is taken by a dropper and then is dropped along the edge of the silicon wafer. The silicon wafer is fixed on the platform by uniformly irradiating the silicon wafer with a UV flashlight with a wavelength of 405 nm for about 5 min. The STL file of a 20 μm line diameter concentric ring model which is previously constructed by Solidworks is introduced, and then the Mofan precise S230 microstereolithography precise printing system is used to normally perform 3D printing operation.

[0059] After the printing is completed, the model is adhered to the silicon wafer, and the silicon wafer is taken off by a blade. The silicon wafer is cleaned with ethanol, and then is placed into DMF for 5 s to remove the residual resin, so as to obtain a silicon wafer with a 20 μm line diameter concentric ring model adhered thereto. Figure 3 and Figure 4 , Figure 3The photo of the printed silicon wafer provided for Example 1, Figure 4 The microscope picture of the micro model on the printed silicon wafer provided for Example 1, from Figure 3 and Figure 4 It can be seen that the method provided in the application has prepared a concentric ring model with a line diameter of 20 μm, and no damage is caused.

[0060] Example 2

[0061] The quartz wafer was cut into a size of about 3*3 cm, and was ultrasonically treated with acetone, anhydrous ethanol and deionized water for 5 min, respectively. Then the surface of the quartz wafer was washed with deionized water, and then the quartz wafer was placed in a cleaning solution (a mixed solution of 98% concentrated sulfuric acid and 30% hydrogen peroxide, with a volume ratio of 7:3) and heated at 140°C for 1 h. Then the quartz wafer was washed with deionized water until no acid solution was left. Then a layer of 10-20 nm thick chromium was deposited on a side of the quartz wafer about 3 mm wide by using a vacuum evaporation machine for focusing.

[0062] 500 μL of silane coupling agent KH-570 was taken by using a pipette and added to 100 mL of toluene to prepare a coupling agent solution. The treated quartz wafer was treated with oxygen plasma for 5 min, and then was immersed in the coupling agent solution for 12 h to obtain a modified quartz wafer. The modified quartz wafer was washed with ethanol and then was blown dry.

[0063] A few drops of light-curing resin were added on the printing platform, and the quartz wafer was placed on the resin to make the resin uniformly fill the gap between the quartz wafer and the platform. The quartz wafer was uniformly irradiated with a 405 nm ultraviolet light flashlight for 3-5 seconds to fix the quartz wafer on the platform. The STL file of a 70 μm wide pentagonal star-shaped model array constructed in advance by using Solidworks was introduced, and then the normal 3D printing operation was performed by using the Mofang Precision S230 microstereolithography precision printing system. After the printing was completed, the model was adhered to the quartz wafer, and the quartz wafer was removed by using a blade. The quartz wafer was washed with ethanol and then was immersed in a DMF solution for 3 seconds to remove the residual resin.

[0064] The quartz wafer was placed in a 10% hydrofluoric acid solution, and was ultrasonically treated at a power of 50 W for 1 min. The model was detached without damage, and was filtered through a stainless steel screen. The obtained model was dispersed in ethanol, and was separated after standing to obtain the model.

[0065] Referring to Figure 5 and Figure 6 , Figure 5 The microscope photo of the printed quartz wafer provided for Example 2, Figure 6 The microscope photo of the detached model provided for Example 2, from Figure 5 and Figure 6It can be seen that the method provided in the application prepares a 70-micron-wide five-star-shaped model, and when the five-star-shaped model is detached from the substrate by using hydrofluoric acid, no damage is caused.

[0066] Example 3

[0067] The difference from Example 1 is that an STL file of a square model array constructed in advance by using Solidworks is imported, wherein the square models in the same column in the square model array have the same size, and the side length of the square models in the same row decreases by 5 microns column by column, and the side length is 50 microns, 45 microns, 40 microns, 15 microns and 10 microns in sequence.

[0068] The results are shown in Table 1. Figure 7 , Figure 7 The microscope photos of the printed silicon wafer provided for Example 3 are shown in Figure 3. Figure 7 It can be seen that the minimum model size that can be printed on the silicon wafer treated by the silane coupling agent is about 10-20 microns.

[0069] Example 4

[0070] The difference from Example 2 is that an STL file of a square model array constructed in advance by using Solidworks is imported, wherein the square models in the same column in the square model array have the same size, and the side length of the square models in the same row decreases by 10 microns column by column, and the side length is 100 microns, 90 microns, 80 microns, 20 microns and 10 microns in sequence.

[0071] The results are shown in Table 2. Figure 8 , Figure 8 The microscope photos of the printed quartz wafer provided for Example 4 are shown in Figure 4. Figure 8 It can be seen that the minimum model size that can be printed on the silicon wafer treated by the silane coupling agent is about 20-30 microns.

[0072] Comparative Example 1

[0073] The difference from Example 4 is that 3D printing is directly performed on a metal platform.

[0074] The results are shown in Table 3. Figure 9 , Figure 9 The microscope photos of the printed metal platform provided for Comparative Example 1 are shown in Figure 5. Figure 9 It can be seen that the minimum model size that can be printed on the metal platform is about 30-40 microns.

[0075] Comparative Example 2

[0076] The difference from Example 4 is that the step of treating the silicon wafer by using a coupling agent solution is omitted.

[0077] The results are shown in Table 4. Figure 10 , Figure 10The microscope photo of the printed silicon wafer provided for Comparative Example 2 shows that no model is attached to the silicon wafer. Figure 10 It can be seen that the minimum model size that can be printed for the untreated silicon wafer is about 60-70 μm.

[0078] Comparative Example 3

[0079] The difference between Example 4 and Comparative Example 3 is that the step of treating the quartz wafer with a coupling agent solution is omitted.

[0080] The results are shown in Table 1. Figure 11 , Figure 11 The microscope photo of the printed quartz wafer provided for Comparative Example 3 shows that no model is attached to the quartz wafer.

[0081] It can be seen that the method provided by the present application improves the adhesion of the model to the substrate and reduces the size of the model that can be printed, i.e. the minimum model size that can be printed is less than the minimum model size of the matching metal platform.

[0082] The above description is merely preferred embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art, according to the technical range disclosed by the present application and the inventive concept thereof, can make equivalent replacements or changes, which should be encompassed in the protection scope of the present application.

Claims

1. A method for preparing a model, characterized in that: The following steps are involved: a) chemically modifying a silicon-based substrate using a siloxane compound containing a double bond to obtain a chemically modified silicon-based substrate; b) fixing the chemically modified silicon-based substrate on a metal platform of a 3D printer, and performing 3D printing according to a pre-constructed model to form a model on the chemically modified silicon-based substrate; c) separating the silicon-based substrate on which the model is formed from the metal platform of the 3D printer; The step a) specifically includes: a1) pre-treating the silicon-based substrate; a2) subjecting the pretreated silicon-based substrate to plasma treatment, and then chemically modifying the substrate with a siloxane compound containing double bonds to obtain a chemically modified silicon-based substrate; The step a1) specifically includes: The silicon-based substrate is cleaned in acetone, anhydrous ethanol and water respectively, and then treated in a cleaning solution, and washed with water to obtain a pretreated silicon-based substrate; The cleaning solution includes concentrated sulfuric acid, hydrogen peroxide and water; The siloxane compound containing a double bond includes one or more of γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, vinyltri(β-methoxyethoxy)silane or vinyltriethoxysilane; The silicon-based substrate is selected from quartz, glass, silicon wafer or silicon dioxide ceramics.

2. The preparation method according to claim 1, characterized in that Also includes: d) treating the silicon-based substrate with the model formed thereon in an acid solution to separate the silicon-based substrate from the model to obtain the model.

3. The preparation method according to claim 2, characterized in that In the step d), the acid solution is hydrofluoric acid.

4. The preparation method according to claim 1, characterized in that The cleaning solution comprises concentrated sulfuric acid and hydrogen peroxide solution in a volume ratio of 50-70:30-50; The concentration of the concentrated sulfuric acid is above 90%; The concentration of the hydrogen peroxide solution is 20 wt % to 40 wt %.

5. The preparation method according to any one of claims 1 to 3, characterized in that In the step b), the light-curable resin used in the 3D printing includes one or more of polyurethane acrylate, epoxy acrylate resin and polyester acrylate resin.

6. The preparation method according to any one of claims 1 to 3, characterized in that In the step b), the chemically modified silicon-based substrate is fixed on the metal platform of the 3D printer using a light-curable resin; In the step c), a cutter is used to separate the silicon-based substrate on which the model is formed from the metal platform of the 3D printer.

7. The preparation method according to any one of claims 1 to 3, characterized in that In the step b), the size of the model is 10 μm to 100 μm.

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