Microstructure film demolding and high-precision transferring method

Abstract

The invention discloses a microstructure film demolding and high-precision transfer method, which belongs to the technical field of flexible optical device processing, and comprises the following steps: bonding an edge boss of a transfer tool flexible layer of a foldable transfer tool with the upper surface of a copied microstructure film; the transfer tool is folded along the edge, and the microstructure film is separated from the microstructure mold under the action of force; the transfer tool obtained after film uncovering is completed is put into a transfer tool clamp, the upper surface and the lower surface of the transfer tool are made to be in the horizontal state, and then the transfer tool and the microstructure film are subjected to secondary bonding through the edge of the microstructure film frame; and cutting a circle along the outer edge of the microstructure film frame by using a cutter, taking the microstructure film and the microstructure film frame as a whole, and taking down the whole from the surface of the flexible layer of the transfer tool. According to the invention, the problem of plastic deformation caused by overlarge adhesive force can be effectively avoided, the dimensional stability of the microstructure film is improved, and the precision and performance of a flexible device are ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of flexible optical device processing, and in particular relates to a microstructure film demoulding and high-precision transfer method. Background Art

[0002] Flexible optical devices, with their advantages of being lightweight and reproducible in large quantities, are expected to replace traditional rigid optical devices in the future and be used in fields such as laser communications and space imaging. However, due to the flexibility of the film, the existing method of manually peeling off the microstructured film and then supporting the film has the problem of not being able to guarantee the macroscopic position accuracy of the microstructure; the method of directly bonding and separating the microstructured film using a film frame has the problem of excessive separation force caused by excessive adhesion between the film and the substrate, which causes plastic deformation. It can be seen that the existing demolding technology cannot guarantee the lateral dimensional accuracy of the film. For microstructured films with microstructures on the surface, this shortcoming is fatal. Summary of the Invention

[0003] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0004] A method for demoulding and high-precision transfer of a microstructured film, comprising:

[0005] Step 1: bonding the microstructure film to the transfer tool; bonding the edge boss of the transfer tool flexible layer of the foldable transfer tool to the upper surface of the replicated microstructure film;

[0006] Step 2: gradually peel off the film; fold the transfer tool along the edge, and the microstructure film is separated from the microstructure mold under the action of force;

[0007] Step 3: The microstructured film is bonded to the transfer tool for a second time; the transfer tool after the film is peeled off is placed in the transfer tool fixture so that the upper and lower surfaces of the transfer tool are horizontal, and then the transfer tool and the microstructured film are bonded for a second time using the edge of the microstructured film frame;

[0008] Step 4, completing the transfer of the microstructured film; using a tool to cut a circle along the outer edge of the microstructured film frame, the microstructured film and the microstructured film frame are removed as a whole from the surface of the flexible layer of the transfer tooling.

[0009] The present invention has the following beneficial effects:

[0010] (1) Compared with the method of manually peeling off the microstructure film and then supporting the film, the present invention uses a foldable transfer tool as an intermediate medium to transfer the microstructure film to the final tool, which can effectively improve the dimensional stability of the microstructure film and ensure the accuracy and performance of the flexible device.

[0011] (2) Compared with the method of directly bonding and separating the microstructured film using a film frame, the present invention gradually peels off the microstructured film by folding the foldable transfer tool, which can effectively avoid the problem of plastic deformation caused by excessive adhesion. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 Schematic diagram of the demoulding and high-precision transfer method of the microstructured film, wherein: 1-transfer tooling rigid layer; 2-transfer tooling flexible layer; 3-microstructured film; 4-microstructured mold; 5-transfer tooling fixture; 6-microstructured film frame;

[0013] Figure 2 3D schematic diagram of the transfer tooling, where (a) is the front view of the transfer tooling, (b) is the back view of the transfer tooling, (c) is the partially folded state of the transfer tooling, and (d) is the fully folded state of the transfer tooling. DETAILED DESCRIPTION

[0014] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only intended to illustrate the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0015] like Figure 1 As shown, the demoulding and high-precision transfer of the microstructured film of the present invention mainly include five steps:

[0016] Step 1: Bond the microstructured film to the transfer tooling; Step 2: Remove the film gradually; Step 3: Bond the microstructured film to the microstructured film frame; Step 4: Complete the transfer of the microstructured film. Step 3 should be bonding the microstructured film to the microstructured film frame.

[0017] In step 1, film edge bonding involves bonding the edge bosses of the foldable transfer fixture's flexible layer 2 to the top surface of the replicated microstructured film 3. The transfer fixture is constructed by stacking a rigid transfer fixture layer 1 and a flexible transfer fixture layer 2. The flexible transfer fixture layer 2 is attached to the rigid transfer fixture layer 1. By folding, the flexible transfer fixture layer 2 achieves longitudinal bending freedom while maintaining lateral dimensional rigidity.

[0018] In step 2, the transfer tool is folded along the edge, and the microstructure film 3 is separated from the microstructure mold 4 under the action of force until the film is peeled off.

[0019] Step 3 includes placing the transfer tooling after film removal into the transfer tooling fixture 5 so that the upper and lower surfaces of the transfer tooling are horizontal, and then performing secondary bonding with the microstructure film 3 using the edge of the microstructure film frame 6 .

[0020] In step 4, a cutter is used to cut a circle along the outer edge of the microstructure film frame 6 , and the microstructure film 3 and the microstructure film frame 6 are removed from the surface of the transfer tool flexible layer 2 as a whole.

[0021] The rigid layer 1 of the transfer tool is a metal or ceramic block material, shaped like Figure 2 As shown, a circular groove is hollowed out on the upper surface of a disc, and then the disc is cut into several strips using a V-shaped cutter. After the cutting is completed, a boss is formed on the edge of the wider upper surface of the strip, and multiple V-shaped gaps are formed on the narrower lower surface of the strip. The function of the V-shaped gap is to provide the space required for the transfer tool to be folded. The function of the transfer tool rigid layer 1 is to provide dimensional stability within the transverse plane of the microstructure film 3. When the transfer tool rigid layer 1 is clamped by the transfer tool fixture 5 and the upper and lower surfaces are confined to one plane, its transverse dimensions are not easily changed.

[0022] The transfer fixture's flexible layer 2 is made of flexible, ultra-thin glass or a flexible polymer film. It is bonded to the transfer fixture's rigid layer 1 using an adhesive. During bonding, the flexible layer 2 and the rigid layer 1 must be aligned seamlessly and flat, without any wrinkles. After bonding, the rigid and flexible layers 1 and 2 form a composite, collectively referred to as the transfer fixture. The transfer fixture resembles a metal watch bracelet. Once released from the transfer fixture fixture's fixture fixture 5, it can bend freely longitudinally, but not laterally.

[0023] The microstructured film 3 is a flexible film material, typically cast from a liquid onto the surface of the microstructured mold 4. After solidifying, it forms a microstructure complementary to that of the mold 4. The microstructured film 3 typically has a flat, unstructured top surface and a microstructured bottom surface. The overall thickness is 10-100 microns, with a microstructure depth of 1-10 microns. Materials for the microstructured film 3 include polyimide, polyurethane, or polymethyl acrylate.

[0024] The microstructure mold 4 is made of a rigid material such as metal or ceramic, and is processed using diamond turning technology or semiconductor etching technology. Its upper surface has a microstructure. The depth of the microstructure is generally 1-10 microns and the width is 10-1000 microns. The total thickness of the microstructure mold 4 is generally 5-20 mm, and the total diameter is slightly larger than the microstructure area.

[0025] The transfer fixture 5 is used to hold the transfer fixture, ensuring that its upper and lower surfaces are flush, free of distortion and misalignment. This can be achieved by using a flat plate and a circular ring to clamp the transfer fixture. In step 1, the transfer fixture 5 can be used to assist in securing the edge bosses of the transfer fixture's flexible layer 2 to the upper surface of the replicated microstructured film 3, ensuring a high-quality bond.

[0026] The microstructured film frame 6 is a rigid circular ring, its flat edges bonded to the microstructured film 3 to provide support. The reason for not directly bonding the microstructured film 3 to the microstructured film frame 6 is that the adhesion between the cast microstructured film 3 and the microstructured mold 4 is very strong, and direct separation would cause plastic deformation of the microstructured film 3. Using a transfer fixture as a buffer allows for gradual separation of the microstructured film 3 from the microstructured mold 4, preventing plastic deformation of the microstructured film 3 while maintaining the lateral dimensional accuracy of the microstructured film 3.

[0027] The above descriptions are merely embodiments of the present invention and are not intended to limit the scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied to other related system fields, are also included in the scope of protection of the present invention.

[0028] The contents not described in detail in the specification of the present invention belong to the prior art known to those skilled in the art.

Claims

1. A method for demoulding and high-precision transfer of a microstructured film, characterized in that: include: Step 1: bonding the microstructure film to the transfer tooling; Bonding the edge boss of the transfer tool flexible layer of the foldable transfer tool to the upper surface of the replicated microstructure film; Step 2, gradually peel off the film; The transfer tool is folded along the edge, and the microstructure film is separated from the microstructure mold under the action of force; Step 3: The microstructured film is bonded to the transfer tool for a second time; the transfer tool after the film is peeled off is placed in the transfer tool fixture so that the upper and lower surfaces of the transfer tool are horizontal, and then the transfer tool and the microstructured film are bonded for a second time using the edge of the microstructured film frame; Step 4, completing the transfer of the microstructured film; using a tool to cut a circle along the outer edge of the microstructured film frame, the microstructured film and the microstructured film frame are removed as a whole from the surface of the flexible layer of the transfer tooling.

2. The method for demoulding and transferring a microstructured film with high precision according to claim 1, wherein: In step 1, the transfer tooling is composed of a transfer tooling rigid layer and a transfer tooling flexible layer stacked together. The transfer tooling flexible layer is attached to the surface of the transfer tooling rigid layer and realizes longitudinal bending freedom by folding, while the transfer tooling maintains lateral dimensional rigidity.

3. The method for demoulding and transferring a microstructured film with high precision according to claim 2, wherein: The transfer tool rigid layer is made of metal or ceramic block material.

4. The method for demoulding and transferring a microstructured film with high precision according to claim 3, wherein: The transfer tooling rigid layer is made by hollowing out a circular groove on the upper surface of a disc and then cutting the disc into several strips using a V-shaped tool; a boss is formed on the edge of the wider upper surface of the strip, and multiple V-shaped gaps are formed on the narrower lower surface of the strip.

5. The method for demoulding and transferring a microstructured film with high precision according to claim 4, characterized in that: The flexible layer of the transfer tooling is flexible ultra-thin glass or flexible polymer film; The flexible layer of the transfer tooling is combined with the rigid layer of the transfer tooling by using an adhesive. During bonding, the positions of the flexible layer of the transfer tooling and the rigid layer of the transfer tooling are aligned without gaps, and the flexible layer of the transfer tooling is flat and wrinkle-free. After bonding is completed, the rigid layer of the transfer tooling and the flexible layer of the transfer tooling form a transfer tooling.

6. The method for demoulding and transferring a microstructured film with high precision according to claim 5, characterized in that: In each step, the microstructure film is a flexible film material, which is cast on the surface of the microstructure mold from a liquid state, and after being converted into a solid state, a microstructure complementary to the microstructure mold is formed.

7. The method for demoulding and transferring a microstructured film with high precision according to claim 6, characterized in that: The upper surface of the microstructure film is flat, and the lower surface has a microstructure. The overall thickness is 10-100 microns, and the microstructure depth is 1-10 microns. The microstructure film material includes polyimide, polyurethane or polymethyl acrylate.

8. The method for demoulding and transferring a microstructured film with high precision according to claim 1, wherein: In step 2, the microstructure mold is made of rigid material and is processed using diamond turning technology or semiconductor etching technology. Its upper surface has a microstructure with a depth of 1-10 microns and a width of 10-1000 microns; the total thickness of the microstructure mold is 5-20 mm, and the total diameter is larger than the microstructure area.

9. The method for demoulding and transferring a microstructured film with high precision according to claim 8, characterized in that: In step 3, the transfer tooling fixture is used to clamp the transfer tooling to ensure that the upper and lower surfaces of the transfer tooling are flush after clamping without distortion or misalignment.

10. The method for demoulding and transferring a microstructured film with high precision according to claim 9, characterized in that: In step 3, the microstructure film frame is a rigid circular ring, and the edge plane of the circular ring is bonded to the microstructure film to achieve support for the microstructure film.

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