A method for preparing a silicone rubber chip with a microporous microvalve

Abstract

The present invention discloses a method for preparing a microporous microvalve silicone rubber chip, comprising the following steps: S1. Coating PCB photosensitive blue oil on a silicon wafer with a nylon wire mesh; S2. Placing the silicon wafer coated with blue oil in an oven for drying, and after drying, cooling it to room temperature; S3. Laying a film with microchannels of the chip on the surface of the blue oil coating, fixing the four corners of the silicon wafer with transparent tape, and exposing it to ultraviolet light, then peeling off the film, soaking the silicon wafer in a developer, brushing off the unexposed part with a brush after soaking and developing, and rinsing with running water. The present invention manufactures the microporous microvalve silicone rubber chip by the method of differential secondary photosensitive blue oil coating with a wire mesh cloth and combining the two exposure methods, avoiding the line width change and technical difficulties caused by long-term exposure of positive photoresist, and at the same time, it does not require multiple exposures, the process is simpler, and the manufacturing process of the chip is shortened, which is beneficial to the preparation of the chip.

Description

Technical Field

[0001] The present invention relates to the technical field of the preparation of microvalve silicone rubber chips, and particularly relates to a method for preparing a microporous microvalve silicone rubber chip. Background Art

[0002] The microporous microvalve chip precisely controls the flow of microfluid in the chip through a microvalve, and connects the pipeline below the cylinder to the pipelines in different directions in the substrate through a micro cylinder lever to complete the opening and closing of the flow path. It is a special chip.

[0003] The male mold of the integrated PDMS chip of the microporous microvalve silicone rubber chip usually uses a positive photoresist, but it has obvious disadvantages. The pipeline is relatively thin (0.5 mm), the channel is shallow (0.1 - 0.2 mm), and at the same time, long-term exposure will cause changes in line width and technical difficulties; if diluted positive photoresist is used for multiple exposure superposition (through multiple coating / exposure, 4 - 5 times), theoretically, a convex male mold with a semicircular cross-section and millimeter-level can be achieved, but the process is complex. Summary of the Invention

[0004] The purpose of the present invention is to solve the disadvantages existing in the prior art, such as: the pipeline is relatively thin, the channel is shallow, and at the same time, long-term exposure will cause changes in line width and technical difficulties; if diluted positive photoresist is used for multiple exposure superposition, theoretically, a convex male mold with a semicircular cross-section and millimeter-level can be achieved, but the process is complex, and a method for preparing a microporous microvalve silicone rubber chip is proposed.

[0005] In order to achieve the purpose of curing the blue oil, the present invention adopts the following technical solutions:

[0006] A method for preparing a microporous microvalve silicone rubber chip, comprising the following steps:

[0007] S1. Coat the PCB photosensitive blue oil on the silicon wafer with a nylon screen;

[0008] S2. Place the silicon wafer coated with blue oil in an oven for drying, and after drying, cool it to room temperature;

[0009] S3. Attach the film (negative film) printed with the microchannels of the chip to the surface of the blue oil coating, fix the four corners of the silicon wafer with transparent tape, expose it with ultraviolet light, then peel off the film, soak the silicon wafer in a developer, and after soaking and developing, use a brush to clean the unexposed part, and rinse it with running water;

[0010] S4. Take out the rinsed silicon wafer and dry it in an oven;

[0011] S5. Take another piece of nylon wire mesh and lay it flat on a smooth plastic plate. Take a small amount of photosensitive blue oil and scrape it across the entire wire mesh with a wire mesh polyurethane squeegee, keeping the photosensitive blue oil moist. Slowly lift the wire mesh that has been scraped with tweezers and transfer it to the upper surface of the silicon wafer.

[0012] S6. Peel the wire mesh from the surface of the silicon wafer, invert the silicon wafer so that its upper surface faces downwards, and place the silicon wafer on a frame with a hollow middle at the same time.

[0013] S7. Then transfer the silicon wafer to an oven for drying. After drying, take out the blue oil silicon wafer, align and cover the surface of the blue oil coating with the original film, and expose it again.

[0014] S8. Peel the film from the silicon wafer, put the silicon wafer into a developer for soaking. After soaking, use a brush to remove the unexposed part, rinse it with running water, blow off the excess water with a hair dryer, and then dry it with an oven. At this time, the preparation of the chip male mold integrated with microchannels and microvalves is obtained.

[0015] S9. Using the chip male mold as a mold, pour and replicate it with silicone rubber AB glue to obtain the silicone rubber pipeline part chip (upper part). Then, after treating the surface of the silicone rubber with air plasma and bonding it with another thin film silicone rubber, a microporous microvalve silicone rubber chip is obtained.

[0016] Preferably, the silicon wafer is a single-sided polished silicon wafer, and the photosensitive blue oil in S1 is applied to the polished side of the silicon wafer.

[0017] Preferably, after the running water rinse in S3, at this time, cured blue oil raised lines appear on the silicon wafer, and the cross-section of the lines is rectangular.

[0018] Preferably, when transferring the wire mesh to the upper surface of the silicon wafer with cured blue oil raised lines, make the wire mesh fit and contact the raised lines on the silicon wafer surface.

[0019] Preferably, when peeling the wire mesh from the surface of the silicon wafer, the photosensitive blue oil adhering to the raised lines on the silicon wafer is in a semi-fluid state.

[0020] Preferably, after placing the silicon wafer on the frame in S6, the silicon wafer needs to be left standing for more than 10 minutes.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: By using the differential secondary photosensitive blue oil coating method of wire mesh cloth and combining the two exposure methods to manufacture the microporous microvalve silicone rubber chip, it avoids the line width change and technical difficulties caused by long-term exposure of positive photoresist. At the same time, it does not require multiple exposures, the process is simpler, the manufacturing process of the chip is shortened, the production time of the chip is reduced, and it is beneficial to the preparation of the chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a flowchart of a method for preparing a microporous microvalve silicone rubber chip proposed by the present invention. Specific embodiments

[0023] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0024] Refer to Figure 1 , a method for preparing a microporous microvalve silicone rubber chip, comprising the following steps:

[0025] S1. Coat the silicon wafer with PCB photosensitive blue oil using a nylon wire mesh.

[0026] S2. Place the silicon wafer coated with blue oil in an oven for drying. After drying, cool it to room temperature.

[0027] S3. Affix the film (negative film) printed with the chip microchannels to the surface of the blue oil coating. Fix the four corners of the silicon wafer with transparent tape and expose it to ultraviolet light. Then peel off the film and soak the silicon wafer in the developer. After soaking and developing, use a brush to clean the unexposed part and rinse it with running water.

[0028] S4. Take out the rinsed silicon wafer and dry it using an oven.

[0029] S5. Take another nylon wire mesh and lay it flat on a smooth plastic plate. Take a small amount of photosensitive blue oil and scrape and fill the entire wire mesh with a wire mesh polyurethane squeegee, keeping the photosensitive blue oil moist. Slowly lift the scraped and filled wire mesh with tweezers and transfer it to the upper surface of the silicon wafer.

[0030] S6. Peel the wire mesh film from the surface of the silicon wafer and invert the silicon wafer so that its upper surface faces down. At the same time, place the silicon wafer on a frame with a hollow middle.

[0031] S7. Then transfer the silicon wafer to an oven for drying. After drying, take out the blue oil silicon wafer and align and cover the surface of the blue oil coating with the original film and expose it again.

[0032] S8. Peel the film from the silicon wafer and soak the silicon wafer in the developer. After soaking, use a brush to remove the unexposed part, rinse it with running water, blow off the excess water with a hair dryer, and then dry it using an oven. At this time, the preparation of the chip male mold integrated with microchannels and microvalves is obtained.

[0033] S9. Using the chip male mold as a die, pour and mold with silicone rubber AB glue to obtain the silicone rubber pipeline part chip (upper part). Then, use air plasma to treat the silicone rubber surface and bond it with another thin film silicone rubber to obtain the microporous microvalve silicone rubber chip;

[0034] The silicon wafer is a single-sided polished silicon wafer, and the photosensitive blue oil in S1 is applied to the polished side of the silicon wafer. After the running water rinse in S3, cured blue oil raised lines appear on the silicon wafer at this time, and the cross-section of the lines is rectangular. When transferring the silk screen to the upper surface of the silicon wafer with the cured blue oil raised lines, make the silk screen fit and contact with the raised lines on the silicon wafer surface, so as to apply the photosensitive blue oil on the raised lines on the silicon wafer surface;

[0035] When peeling the silk screen from the silicon wafer surface, the photosensitive blue oil adhering to the raised lines on the silicon wafer is in a semi-fluid state, and at this time the photosensitive blue oil can flow and deform. After placing the silicon wafer on the frame in S6, the silicon wafer needs to be left standing for more than 10 minutes to make the semi-fluid photosensitive blue oil form a semicircle under the action of gravity suspension.

[0036] In the present invention, when the device is in use, first, a PCB photosensitive blue oil is coated on a single-sided polished silicon wafer with a nylon wire mesh. Then, the silicon wafer coated with the blue oil is placed in an oven for drying. After the silicon wafer is dried, wait for the silicon wafer to cool to room temperature. Then, a film with microchannels of the chip is overlaid on the surface of the blue oil coating, and the four corners of the silicon wafer are fixed by transparent tape. After the fixation is completed, the silicon wafer is exposed using an ultraviolet lamp. After the exposure is completed, the film is peeled off from the surface of the silicon wafer, and the silicon wafer is immersed in a developing solution for soaking and developing. After the silicon wafer is developed, the silicon wafer is taken out, and the unexposed part on the surface of the silicon wafer is cleaned with a brush. After the cleaning is completed, the silicon wafer is rinsed with running water. At this time, cured blue oil raised lines appear on the silicon wafer, and the cross-section of the lines is rectangular. Then, the silicon wafer is dried using an oven. At the same time, another nylon wire mesh is taken and laid flat on a flat and smooth plastic plate. A small amount of photosensitive blue oil is taken and scraped and filled in the entire wire mesh to keep the photosensitive blue oil moist. There is sufficient photosensitive blue oil filled between the wire meshes. The wire mesh that has been scraped and filled is slowly lifted with tweezers, and the wire mesh film is transferred to the upper surface of the silicon wafer with cured blue oil raised lines, so that the wire mesh film is in contact with the raised lines on the surface of the silicon wafer. Then, the wire mesh film is peeled off from the surface of the silicon wafer. At this time, the photosensitive blue oil adhered to the raised lines on the surface of the silicon wafer is in a semi-fluid state. Then, the silicon wafer is inverted, with the upper surface of the silicon wafer facing down in an inverted state. At the same time, the silicon wafer is placed on a frame with a hollow middle and left standing for more than 10 minutes to facilitate the flow and deformation of the semi-fluid photosensitive blue oil. The semi-fluid photosensitive blue oil forms a semicircle under the action of gravity suspension. Then, the silicon wafer in this state is transferred to an oven for drying treatment. Next, the dried blue oil silicon wafer is taken out. At the same time, the original film is used to closely align and cover the surface of the blue oil coating, and it is exposed again using ultraviolet light. After the exposure is completed, the film is peeled off, and the silicon wafer is immersed in the developing solution. After the immersion is completed, the silicon wafer is taken out, and the unexposed part on the silicon wafer is removed with a brush, especially the residual photosensitive blue oil between the convex lines, which needs to be cleaned thoroughly. After the photosensitive blue oil is cleaned, the silicon wafer is rinsed with running water, and then the excess water is blown off with a hair dryer, and the silicon wafer is dried using an oven. Thus, the preparation of the chip male mold integrated with microchannels and microvalves is obtained. Finally, taking the chip male mold as a mold, a silicone rubber AB glue is used for casting and mold flipping, so as to obtain a silicone rubber pipeline part chip (upper part). Then, after treating the surface of the silicone rubber with air plasma and bonding it with another thin film silicone rubber, a microporous microvalve silicone rubber chip is obtained.

[0037] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered within the protection scope of the present invention.

Claims

1. A method for preparing a silicone rubber chip with a microporous microvalve, characterized in that, Including the following steps: S1. Coat the silicon wafer with PCB photosensitive blue oil using a nylon screen; S2. Place the silicon wafer coated with blue oil in an oven for drying. After drying, cool it to room temperature; S3. Affix the film with printed chip microchannels onto the surface of the blue oil coating. Fix the four corners of the silicon wafer with transparent tape, expose it to ultraviolet light, then peel off the film, soak the silicon wafer in a developer, brush away the unexposed part after soaking and developing, and rinse with running water; S4. Take out the rinsed silicon wafer and dry it using an oven; S5. Take another nylon screen and lay it flat on a smooth plastic plate. Take a small amount of photosensitive blue oil and scrape it across the entire screen with a screen polyurethane squeegee to keep the photosensitive blue oil moist. Slowly lift the scraped screen film with tweezers and transfer it to the upper surface of the silicon wafer; S6. Peel the screen film from the surface of the silicon wafer, invert the silicon wafer so that its upper surface faces down, and place the silicon wafer on a frame with a hollow middle; S7. Then transfer the silicon wafer to an oven for drying. After drying, take out the blue oil silicon wafer, align and cover the surface of the blue oil coating with the original film, and expose it again; S8. Peel the film from the silicon wafer, put the silicon wafer into a developer for soaking. After soaking, use a brush to remove the unexposed part, rinse with running water, blow off the excess water with a hair dryer, and then dry it with an oven. At this time, the preparation of the chip male mold with integrated microchannels and microvalves is obtained; S9. Using the chip male mold as a mold, pour and replicate it with silicone rubber AB glue to obtain a silicone rubber pipe part chip. After treating the surface of the silicone rubber with air plasma and bonding it with another thin film silicone rubber, a microporous microvalve silicone rubber chip is obtained.

2. The method for preparing a microporous microvalve silicone rubber chip according to claim 1, wherein, The silicon wafer is a single-sided polished silicon wafer, and the photosensitive blue oil in S1 is applied to the polished side of the silicon wafer.

3. A method for preparing a microporous microvalve silicone rubber chip according to claim 1, characterized in that, After the running water rinse in S3, cured blue oil raised lines appear on the silicon wafer at this time, and the cross-section of the lines is rectangular.

4. A method for preparing a microporous microvalve silicone rubber chip according to claim 3, characterized in that, When transferring the screen film to the upper surface of the silicon wafer with cured blue oil raised lines, make the screen film fit and contact the raised lines on the silicon wafer surface.

5. A method for preparing a microporous microvalve silicone rubber chip according to claim 1, characterized in that, When peeling the screen film from the surface of the silicon wafer, the photosensitive blue oil adhered to the raised lines on the silicon wafer is in a semi-fluid state.

6. A method for preparing a microporous microvalve silicone rubber chip according to claim 1, characterized in that, After placing the silicon wafer on the frame in S6, the silicon wafer needs to be left standing for more than 10 minutes.

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