A hot pressing method for a microfluidic chip and a microfluidic chip

Abstract

The present invention belongs to the technical field of microfluidic chips, and particularly relates to a hot pressing method for a microfluidic chip and a microfluidic chip. The hot pressing method for the microfluidic chip comprises the following steps: mold making, preparing a forming mold, the forming mold comprising: preparing a master mold and a punch, at least two punches being prepared, and the heights of at least two punches being different; detachably connecting the master mold to one of the punches; heating, abutting the punch against a blank, and heating the blank, the punch and the master mold; hot pressing, enabling there to be a hot pressure between the punch and the blank, so that the punch extrudes the blank, and the blank replicates the shape of the punch to process the blank into a microfluidic chip; demolding, cooling the microfluidic chip, the master mold and the punch, and separating the microfluidic chip and the punch. The present invention can process different microchannel chips through a set of forming molds, reducing the preparation cost of preparing a variety of different microchannel chips.

Description

Technical Field

[0001] The present invention belongs to the technical field of microfluidic chips, and particularly relates to a hot pressing method for a microfluidic chip and a microfluidic chip. Background Art

[0002] A microfluidic chip is a small device integrating a complex fluid control system, usually composed of multiple micro-scale or nano-scale flow channels, pumps and valves, which can precisely control the liquid flow. By processing liquid samples in micro-channels, the analysis efficiency can be improved, the sample volume can be reduced, and high-resolution results can be provided, which are widely used in the fields of biomedical diagnosis, drug research and development, environmental monitoring, chemical analysis, etc.

[0003] Currently, the manufacturing methods of microfluidic chips include soft lithography technology, hot embossing, inkjet printing, and laser micromachining. Among them, the glass precision molding technology is relatively mature, and the thermoforming method is suitable for mass production and low-cost manufacturing of glass microfluidic chips. The production of glass microfluidic chips has very high requirements for the surface accuracy of the molding die, and the surface quality of the molding die determines the quality of the microfluidic channels after processing. The material of the molding die is usually a high-temperature resistant material, such as tungsten carbide, silicon carbide, glassy carbon, etc. These materials have high hardness and brittleness, and ultrasonic milling is often used for processing.

[0004] However, the ultrasonic milling processing cost is high. Especially when preparing different microfluidic chips, multiple sets of molding dies need to be processed separately, which often leads to too high preparation cost of microfluidic chips. Summary of the Invention

[0005] The purpose of the embodiments of the present application is to provide a hot pressing method for a microfluidic chip, aiming to solve the problem of how to reduce the preparation cost when processing different microfluidic chips.

[0006] To achieve the above purpose, the technical solution adopted in the present application is:

[0007] In a first aspect, a hot pressing method for a microfluidic chip is provided, which includes the following steps:

[0008] Mold making, preparing a molding die, the molding die includes: a master die and a punch cooperating with the master die, at least two punches are prepared, and at least two of the punches have different heights; detachably connect the master die to one of the punches;

[0009] Heating, arranging the punch relative to the blank, heating the blank, the punch and the master die;

[0010] Hot pressing, making there be a hot pressure between the punch and the blank, so that the punch extrudes the blank, and the blank replicates the shape of the punch to process the blank into a microfluidic chip;

[0011] Demold, cool the microfluidic chip, and separate the microfluidic chip and the male mold.

[0012] In some embodiments, the male mold is in a sheet shape. The mold manufacturing step includes machining a positioning groove on the master mold. The shape of the positioning groove is adapted to the shape of the male mold. Insert and position the male mold in the positioning groove, such that a part of the male mold is located in the positioning groove and another part of the male mold abuts against the blank.

[0013] In some embodiments, the male mold is arranged in a meandering shape.

[0014] In some embodiments, the master mold has a mounting surface, and the positioning groove is opened on the mounting surface. The mold manufacturing step further includes a polishing step, and the polishing step includes:

[0015] Polish the mounting surface;

[0016] Polish both side surfaces of the male mold and the end surface for hot pressing the blank.

[0017] In some embodiments, the positioning groove penetrates through opposite side surfaces of the master mold. The hot pressing method for the microfluidic chip further includes preparing a pressing plate, arranging the pressing plate on one side of the master mold to cover the positioning groove, and the male mold is located on the other side of the master mold.

[0018] In some embodiments, the master mold is machined using a slow wire electrical discharge machining process to machine the positioning groove on the master mold; the male mold is machined on a template using the slow wire electrical discharge machining process.

[0019] In some embodiments, the slow wire electrical discharge machining process is repeated multiple times.

[0020] In some embodiments, two positioning grooves are opened, and the extending paths of the two positioning grooves have different shapes. The shapes of two male molds are respectively adapted to the shapes of the two positioning grooves.

[0021] In some embodiments, the heating step includes preparing a sleeve and a heating tube. The blank, the master mold, and the male mold are placed and positioned in the sleeve. The heating tube is arranged along the circumferential direction of the sleeve and is used to heat the blank, the master mold, and the male mold.

[0022] In a second aspect, there is provided a microfluidic chip prepared by the hot pressing method of the microfluidic chip.

[0023] The beneficial effects of the present application are as follows: By preparing a master mold and at least two punch molds, the different punch molds are detachably connected to the master mold, so that different molding molds can be combined to form different molding molds. Then, by hot-pressing the blank with the molding mold, different blanks can be processed into different microfluidic chips respectively. Different microfluidic chips can be processed with a set of molding molds, avoiding the simultaneous development of two sets of molding molds and reducing the preparation cost of preparing multiple different microfluidic chips. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or exemplary technical descriptions. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0025] Figure 1 is a flowchart of a hot-pressing method for a microfluidic chip provided by an embodiment of the present application;

[0026] Figure 2 is an exploded schematic view of a molding mold, a sleeve, and a blank provided by another embodiment of the present application;

[0027] Figure 3 is Figure 2 an exploded schematic view of the punch mold and the master mold of the molding mold;

[0028] Figure 4 is Figure 1 a cross-sectional schematic view of the assembled molding mold, sleeve, and blank.

[0029] Among them, the reference numerals in the drawings are as follows:

[0030] 10, pressure plate; 20, blank; 30, molding mold; 31, punch mold; 32, master mold; 40, sleeve; 50, heating tube; 322, mounting surface; 321, positioning groove. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] In order to make the objectives, technical solutions, and advantages of the present application clearer, the following further describes the present application in detail with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present application.

[0032] It should be noted that when a component is referred to as "fixed to" or "disposed on" another component, it can be directly on the other component or indirectly on the other component. When a component is referred to as "connected to" another component, it can be directly or indirectly connected to the other component. The orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation to this application. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances. The terms "first" and "second" are only used for the purpose of convenient description, and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of technical features. The meaning of "a plurality" is two or more, unless otherwise specifically and clearly defined.

[0033] Please refer to Figures 1 to 3 , an embodiment of the present application provides a hot pressing method for a microfluidic chip, which is used to prepare a blank 20 into a microfluidic chip. The blank 20 can be a thermoplastic material, such as plastic or glass. In this embodiment, the blank 20 is a plate-shaped glass, and in other embodiments, it can also be selected according to actual situations, and no limitation is made here. The microfluidic chip has characteristics such as high precision, good chemical inertness, good optical transparency, and precise fluid control ability, and is therefore widely used in fields such as biomedicine, chemical analysis, environmental monitoring, drug development, and food safety.

[0034] Please refer to Figures 1 to 3 , the hot pressing method of the microfluidic chip includes the following steps:

[0035] S1: Mold making, preparing a forming mold 30. The forming mold 30 includes a female mold 32 and a male mold 31 that cooperates with the female mold 32. The female mold 32 can be used to fix the male mold 31, and the male mold 31 is used to hot press the blank 20. The mold making includes the following steps:

[0036] S11: Preparing the female mold 32. The female mold 32 is integrally plate-shaped, and the material of the female mold 32 can be a high-temperature resistant hard material, such as tungsten carbide.

[0037] S12: Preparing the male mold 31. At least two male molds 31 are prepared, and at least two male molds 31 have different heights; detachably connect the female mold 32 to one of the male molds 31. After the male mold 31 is connected to the female mold 32, the height of the male mold 31 is arranged in the vertical direction;

[0038] It can be understood that when the punch dies 31 are placed on the same horizontal plane, the heights of the punch dies 31 are different. When the punch die 31 is installed on the female die 32, the distance between the end face of the punch die 31 for hot pressing the blank 20 and the surface of the female die 32 where the punch die 31 is installed is also different, so that a forming die 30 with different hot pressing depths can be formed, and microchannels with different depths can be hot pressed on the blank 20. Furthermore, at least two different microfluidic chips can be prepared using a set of forming dies 30.

[0039] The microchannel can be a micro-nano structure with dimensions in the micron and / or nanometer range. In this application, the microchannel has a groove structure with a groove width of 0.2 mm.

[0040] S2: Heating. The punch die 31 is arranged relative to the blank 20, or the punch die 31 is directly abutted against the blank 20, and the blank 20, the punch die 31 and the female die 32 are heated. The blank 20 can be fixed on the workbench, and the punch die 31 is located above the blank 20, or the punch die 31 and the female die 32 are fixed on the workbench, and the blank 20 is located above the punch die 31. In this embodiment, the punch die 31 is located above the blank 20. In other embodiments, it can be selected according to the actual situation and is not limited here.

[0041] Please refer to Figure 4 , a heating structure can be used to heat the blank 20 and the forming die 30. The heating structure can transfer heat by means of heat conduction or heat radiation. For example, the heating structure can generate heat through an infrared heating tube. The temperature of the blank 20 can be heated to near its glass transition temperature by the heating structure, such as exceeding the glass transition temperature by 20 degrees Celsius, so as to soften the blank 20 and improve the plasticity of the blank 20. The heating environment of the blank 20 can be a vacuum environment or an inert gas environment, so as to avoid oxidation of the blank 20. The vacuum degree of the vacuum environment can be 0.001 Pa, and the inert gas can be nitrogen or argon.

[0042] S3: Hot pressing. Apply a hot pressure between the punch die 31 and the blank 20, such as applying a hot pressure towards the blank 20 on the female die 32, so that the punch die 31 extrudes the blank 20, and the blank 20 replicates the shape of the punch die 31, and a microchannel is machined on the blank 20, and finally the blank 20 is machined into a microfluidic chip.

[0043] It can be understood that when the blank 20 is located below the punch die 31, the direction of the hot pressure is vertically downward and points to the blank 20. The hot pressure drives the punch die 31 to move downward to replicate the shape of the punch die 31 on the blank 20 and keep the pressure for a certain time to improve the replication accuracy of the blank 20 to the punch die 31.

[0044] When the blank 20 is located above the punch die 31, the direction of the hot pressure is vertically downward and points to the punch die 31, asFigure 4 As shown by the arrow. The hot pressure drives the blank 20 to move downward to copy the shape of the punch 31 onto the blank 20, and keep the temperature and pressure constant for a certain period of time to improve the replication accuracy of the blank 20 to the punch 31. The time can be 5 minutes.

[0045] S4: Demold, cool the microfluidic chip, the master mold 32 and the punch 31, and separate the microfluidic chip and the punch 31;

[0046] It can be understood that nitrogen gas with a lower temperature can be blown onto the blank 20 and the forming mold 30 after hot pressing, so as to cool the blank 20 and the forming mold 30 and obtain the microfluidic chip. The temperature range of the nitrogen gas can be -100 °C to 0 °C.

[0047] Please refer to Figures 1 to 3 , the hot pressing method of the microfluidic chip provided by the embodiment of the present application, by preparing the master mold 32 and at least two punches 31, detachably connecting different punches 31 to the master mold 32, different forming molds 30 can be combined to form, and then hot pressing the blank 20 through the forming mold 30, so that different blanks 20 can be processed into different microchannel chips respectively. Different microchannel chips can be processed through a set of forming molds 30, avoiding the simultaneous development of two sets of forming molds 30 and reducing the preparation cost of preparing multiple different microchannel chips.

[0048] It can be understood that the punch 31 on the master mold 32 is replaced with another punch 31 with a different height, and the heating, hot pressing and demolding steps are repeated on another blank 20, that is, only by installing the corresponding punch 31 on the master mold 32, the corresponding microfluidic chip can be processed, so that two different microfluidic chips can be processed through a set of forming molds 30. Of course, the number of punches 31 can also be set to three or more, and the heights of the punches 31 are all different, which is not limited here and can be selected according to the actual situation.

[0049] It can be understood that the materials of the master mold 32 and the punch 31 can be tungsten carbide, silicon nitride or glassy carbon.

[0050] Please refer to Figures 1 to 3 , in some embodiments, the punch 31 is in a sheet shape, and the mold making step further includes processing a positioning groove 321 on the master mold 32. The shape of the positioning groove 321 is adapted to the shape of the punch 31. For example, when the punch 31 is in a flat plate shape as a whole, the extension path of the positioning groove 321 is a straight line. The positioning groove 321 can be a blind groove structure or a through groove structure. The punch 31 can be inserted and positioned in the positioning groove 321, that is, a part of the punch 31 is located in the positioning groove 321, and the other part of the punch 31 is exposed and can abut against the blank 20.

[0051] Optionally, the punch 31 is in the shape of a thin sheet, and the positioning groove 321 can achieve the detachable connection between the punch 31 and the female mold 32. The exposed part of the punch 31 can perform hot pressing on the blank 20, and the exposed parts of the punches 31 with different heights have different heights, so that microchannels with different depths can be hot-pressed on the blank 20.

[0052] Please refer to Figures 1 to 3 , in some embodiments, the punch 31 is arranged in a meandering shape, and the shape of the positioning groove 321 is adapted to the meandering shape of the punch 31.

[0053] Please refer to Figures 1 to 3 , it can be understood that the extension path of the punch 31 is in a meandering snake shape, and it has small-radius bending corners, and the curvature radius range at the corners can be 0.1 - 2 mm. The forming die 30 is set to be split, and the female mold 32 and the punch 31 can be processed separately, and then the punch 31 and the female mold 32 are assembled. When the female mold 32 and the punch 31 are processed separately, any surface of the female mold 32 or the punch 31 can be effectively processed, such as effective polishing, avoiding the problem that the right-angle edges at the connection of the punch 31 and the female mold 32 are not easy to polish. Moreover, when processing the position with a small-radius bend of the punch 31, there is also enough tool feed space, and a high-precision female mold 32 and a punch 31 that meet the shape requirements can be processed. And separate processing does not require complex processes and the use of complex tools, reducing the processing cost and improving the processing efficiency.

[0054] Optionally, when the punch 31 hot-presses the blank 20, microchannels with corresponding shapes can be processed on the blank 20, and the serpentine meandering positioning groove 321 can increase the contact area between the female mold 32 and the punch 31, and can achieve the connection between the punch 31 and the female mold 32 in multiple directions, improving the stability and reliability of the connection between the female mold 32 and the punch 31. And during the hot-pressing process, the punch 31 can apply force to the blank 20 evenly at multiple different positions. The multi-point force in the longitudinal and transverse directions can make the blank 20 be stressed evenly as a whole, improving the hot-pressing accuracy of the microchannels.

[0055] In some embodiments, the female mold 32 has a mounting surface 322. During the hot-pressing process, when the blank 20 is located below the punch 31, the mounting surface 322 is arranged downward, and when the blank 20 is located above the punch 31, the mounting surface 322 is arranged upward. The positioning groove 321 is opened on the mounting surface 322, and the mold-making steps further include a polishing step.

[0056] S13: The polishing step includes:

[0057] S131: Polish the mounting surface 322;

[0058] S132: Polish the two side surfaces of the punch 31 and the end surface for hot-pressing the blank 20.

[0059] Please refer to Figures 2 to 4 Figures 2 to 4 , optionally, an ultrasonic polishing process can be used to polish the mounting surface 322 and the punch 31 respectively. Separately polishing the female mold 32 and the punch 31 can improve the convenience and effect of polishing, avoid forming a polishing dead angle at the connection between the punch 31 and the female mold 32, that is, avoid forming an unpolishable area in the right-angle area between the side surface of the punch 31 and the mounting surface 322, improve the polishing accuracy of the forming mold 30, and thus can improve the hot pressing accuracy of the blank 20.

[0060] Please refer to Figures 2 to 4 Figures 2 to 4 , in some embodiments, the positioning groove 321 penetrates through the opposite two side surfaces of the female mold 32. The hot pressing method for the microfluidic chip further includes preparing a pressing plate 10, setting the pressing plate 10 on one side of the female mold 32 to cover the positioning groove 321, with the punch 31 located on the other side of the female mold 32, and applying a hot pressing force on the pressing plate 10 to make the blank 20 replicate the shape of the punch 31.

[0061] By making the positioning groove 321 penetrate through the two side surfaces of the female mold 32, it is convenient to process the female mold 32 and improve the convenience of processing the positioning groove 321.

[0062] Optionally, when the punch 31 is located above the blank 20, the punch 31 located in the positioning groove 321 can be limited by the pressing plate 10, and the pressing plate 10 can also drive the female mold 32 and the punch 31 to move towards the blank 20 as a whole.

[0063] When the blank 20 is located above the punch 31, the pressing plate 10 covers the blank 20, the female mold 32 is positioned on the workbench, and the punch 31 is limited by the lower workbench. The pressing plate 10 can drive the blank 20 to move towards the punch 31 as a whole.

[0064] In some embodiments, the female mold 32 is processed using a wire electrical discharge machining (WEDM) process to machine the positioning groove 321 on the female mold 32. The punch 31 can also be machined on the template using the wire electrical discharge machining process.

[0065] Optionally, due to the diameter of the cutter head, milling cannot machine small-radius corners or curved surfaces, while the wire electrical discharge machining process can machine small-radius corners, such as a corner with a radius of 0.2 mm. Therefore, the present application can reduce the processing difficulty of the female mold 32 and the punch 31 and improve the processing convenience.

[0066] Please refer to Figures 2 to 4, in some embodiments, the female mold 32 or the male mold 31 is placed in the oil. The electrical pulse interval of the slow wire electrical discharge machining process is 10 μs, and the oil speed of the oil is 7 L / min to machine the female mold 32 or the male mold 31 that meets the requirements. The slow wire electrical discharge machining process can machine high-hardness materials and complex shapes, which is suitable for the complex shape machining requirements of the positioning groove 321 and the male mold 31, ensuring the accuracy of the forming mold 30 and improving the forming effect of the microchannel.

[0067] Optionally, after the electrical discharge machining is completed, the surfaces of the female mold 32 and each male mold 31 need to be polished and cleaned by ultrasonic vibration with alcohol.

[0068] Please refer to Figures 2 to 4 , in some embodiments, the slow wire electrical discharge machining process is repeated multiple times to perform multiple precision trimming cuts on the female mold 32 and the male mold 31, improving the machining accuracy of the female mold 32 and the male mold 31.

[0069] Optionally, to improve the surface quality and assembly accuracy of the female mold 32 and the male mold 31, the number of precision trimming cuts is 10 times, and the surface roughness of the female mold 32 and the male mold 31 can reach 70 nm.

[0070] Please refer to Figures 2 to 4 , in some embodiments, two positioning grooves 321 are provided. The shapes of the extension paths of the two positioning grooves 321 are different, and the shapes of the two male molds 31 respectively match the shapes of the two positioning grooves 321.

[0071] Optionally, the shape of the extension path of one of the positioning grooves 321 can be a straight line, and the corresponding male mold 31 is a straight-shaped male mold 31; while the shape of the extension path of the other positioning groove 321 can be an arc, and the corresponding male mold 31 is an arc-shaped male mold 31. Thus, male molds 31 with different shapes can be assembled on one female mold 32, and different male molds 31 can simultaneously hot-press different-shaped microchannels on the blank 20, reducing the preparation cost of different microfluidic chips.

[0072] Please refer to Figures 2 to 4 , in some embodiments, the heating step further includes preparing a heating structure. The heating structure includes a sleeve 40 and a heating tube 50. The blank 20, the male mold 31, and the female mold 32 are placed and positioned in the sleeve 40, and the heating tube 50 is arranged along the circumferential direction of the sleeve 40 and is used to heat the blank 20, the female mold 32, and the male mold 31.

[0073] Optionally, the heating tube 50 can be a ceramic heating tube or an infrared heating tube, which is not limited here and can be selected according to the actual situation. Using the sleeve 40 and the circumferentially arranged heating tube 50 to uniformly heat the blank 20, the female mold 32, and the male mold 31 can avoid uneven heating of the blank 20 caused by local overheating, improving the processing efficiency and forming accuracy.

[0074] Please refer to Figures 2 to 4 , the hot pressing method of the microfluidic chip provided by the embodiment of the present application aims to improve the processing efficiency of the glass microfluidic chip and reduce its manufacturing cost, and has the following characteristics:

[0075] Flexible combination. The forming die 30 is a split die. By replacing the punch 31 with different heights, different forming dies 30 can be formed by combining with the same master die 32, so that microchannels with different depths can be processed on the blank 20.

[0076] Convenient for polishing. The master die 32 and the punch 31 can be disassembled, so that the master die 32 and the punch 31 can be polished separately. The separate polishing of the two components can manufacture a microfluidic chip with high surface quality.

[0077] Reduce the processing difficulty. The slow wire cut electrical discharge machining can process small-radius bends, reducing the processing difficulty and cost.

[0078] Please refer to Figures 2 to 4 , the present invention also proposes a microfluidic chip, which is prepared by the hot pressing method of the above-mentioned microfluidic chip. For the specific steps of the hot pressing method of the microfluidic chip, please refer to the above-mentioned embodiment. Since this microfluidic chip adopts all the technical solutions of the above-mentioned all embodiments, it also has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be elaborated here one by one.

[0079] Optionally, a precision molding press can be used to implement the hot pressing method of the microfluidic chip, and a glass microfluidic chip can be manufactured through heating, hot pressing, cooling, and demolding.

[0080] The above are only optional embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

Claims

1. A hot pressing method for a microfluidic chip, characterized in that: The steps include: Molding, preparing a molding die, the molding die comprising: a mother die and a convex die matched with the mother die, at least two convex die are prepared, and at least two of the convex die have different heights; the mother die is detachably connected to one of the convex die; the molding die is set to be split, so as to process the mother die and the convex die separately, and then the convex die and the mother die are assembled, and when processing the small radius bending position of the convex die, there is enough feed space; Heating, placing the male mold relative to the blank, and heating the blank, the male mold and the female mold; Hot pressing, so that there is hot pressure between the convex mold and the blank, so that the convex mold squeezes the blank, and the blank replicates the shape of the convex mold, so that the blank is processed into a microfluidic chip; Demolding, cooling the microfluidic chip, and separating the microfluidic chip and the convex mold; The male mold is in the form of a sheet, and the molding step includes machining a positioning groove on the female mold, the shape of the positioning groove being adapted to the shape of the male mold, inserting and positioning the male mold in the positioning groove, and making a portion of the male mold located in the positioning groove, and making another portion of the male mold abut against the blank; The punch is arranged in a serpentine shape, and the shape of the positioning groove is adapted to the serpentine shape of the punch. The serpentine positioning groove can increase the contact area between the female mold and the punch, and can realize the connection between the punch and the female mold in multiple directions.

2. The hot pressing method of the microfluidic chip according to claim 1, characterized in that: The mother mold has a mounting surface, the positioning groove is opened on the mounting surface, and the molding step also includes a polishing step, and the polishing step includes: polishing the mounting surface; The two side surfaces of the punch and the end surface used for hot pressing the blank are polished.

3. The hot pressing method of the microfluidic chip according to claim 1, characterized in that: The positioning groove runs through the two opposite surfaces of the mother mold. The hot pressing method of the microfluidic chip also includes preparing a pressing plate, which is arranged on one side of the mother mold and covers the positioning groove. The convex mold is located on the other side of the mother mold.

4. The hot pressing method for a microfluidic chip according to any one of claims 1 to 3, characterized in that: The master mold is processed by using an electric spark wire cutting process to form the positioning groove on the master mold; and the male mold is processed on the template by using the electric spark wire cutting process.

5. The hot pressing method of the microfluidic chip according to claim 4, characterized in that: The electric spark wire walking process is repeated multiple times.

6. The hot pressing method for a microfluidic chip according to any one of claims 1 to 3, characterized in that: There are two positioning grooves, and the shapes of the extension paths of the two positioning grooves are different, wherein the shapes of the two punches are respectively adapted to the shapes of the two positioning grooves.

7. The hot pressing method for a microfluidic chip according to any one of claims 1 to 3, characterized in that: The heating step includes preparing a sleeve and a heating tube, wherein the blank, the mother mold and the male mold are placed and positioned in the sleeve, and the heating tube is arranged along the circumference of the sleeve and is used to heat the blank, the mother mold and the male mold.

8. A microfluidic chip, characterized in that: The microfluidic chip is prepared by the hot pressing method of the microfluidic chip described in any one of claims 1 to 7.

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