Microlens preparation method

Abstract

The invention provides a micro-lens preparation method, which comprises the following steps that a pressing die is provided, one side of the pressing die is an impressing side, and a plurality of microstructures matched with the surface type of a micro-lens are formed on the impressing side; applying a first colloid on the impressing side point; a first substrate is provided, the first substrate is used for pressing the first colloid, then the first colloid is solidified, the side, where the first colloid is pressed, of the first substrate is a first pressing side, and the first pressing side is provided with an anti-sticking layer used for preventing adhesion of the first colloid; separating the first substrate from the cured first colloid; dispensing a second colloid on the first colloid; and providing a second substrate, pressing a second colloid by using the second substrate, and then curing the second colloid so that the first colloid and the second colloid are combined together. The micro-lens preparation method provided by the invention is suitable for preparing a high-rise micro-lens, the surface precision of the prepared micro-lens structure can be ensured by the method, and the thickness of the micro-lens structure at the center and the thickness of the micro-lens structure at the periphery can be kept consistent.

Description

Technical Field

[0001] The invention relates to the field of optical optoelectronic technology, and in particular to a method for preparing a microlens. Background Art

[0002] In the existing microlens preparation method, Figure 1-2 As shown, the following steps are included: a colloid 20' is applied to the stamping side of the stamping mold 10', and a plurality of grooves 11' for forming a plurality of microlens structures are formed on the stamping side; then, the colloid 20' is pressed using a substrate 30' to fill the colloid 20 into the grooves 11'; and then, the colloid 20' is cured.

[0003] The side of the substrate 30' close to the colloid 20' is coated with an adhesion promoter 31', and the colloid 20' is adhered to the substrate 30' through the adhesion promoter 31'. When the colloid 20' is cured, the colloid 20' undergoes a cross-linking reaction, and its volume shrinks. Since the adhesion promoter 31' adheres to the substrate 30' and the colloid 20', when the colloid 20' shrinks, it will gather at the substrate 30', resulting in an increase in the difference between the shrinkage value at the center and the shrinkage value at the edge of the microlens structure 40' (e.g. Figure 2 As shown in FIG. 2 , after the colloid 20' is cured, the surface shape of the microlens structure 40' will be different from the theoretical surface shape. When preparing a microlens with a low sagittal height, the difference is acceptable, but when preparing a microlens with a high sagittal height, the difference is large and the microlens cannot meet the functional requirements.

[0004] In addition, in the above steps, the colloid 20' is placed on the imprinting side according to the set amount, and after the substrate 30' is pressed down, the colloid 20' diffuses outward. When preparing a microlens with a low sagittal height, the surface tension of the colloid 20' can prevent the colloid 20' from excessively diffusing outward due to its own gravity during the pressing process of the substrate 30'. When preparing a microlens with a high sagittal height, since a large amount of colloid 20' is required, the surface tension of the colloid 20' cannot prevent the glue from excessively diffusing outward. In this way, on the cured colloid 20', there will be a large difference in thickness between the microlens structure 40' at the center and the microlens structure 40' at the edge. Summary of the invention

[0005] The present invention provides a method for preparing a microlens, which aims to solve the problems in the prior art that, when preparing a microlens with a high sagittal height, the surface shape of the microlens structure is greatly different from the theoretical surface shape, and that on the cured colloid, the thickness of the microlens structure at the center and the microlens structure at the edge are greatly different.

[0006] To achieve the above object, the present invention provides a method for preparing a microlens, the method comprising the following steps:

[0007] Providing a stamping die, one side of the stamping die being a stamping side, and the stamping side being formed with a plurality of microstructures matching the surface shape of the microlens;

[0008] Applying a first colloid on the stamping side;

[0009] Providing a first substrate, using the first substrate to press the first colloid, and then curing the first colloid, the side of the first substrate where the first colloid is pressed is a first pressing side, and the first pressing side has an anti-sticking layer for preventing the first colloid from sticking;

[0010] separating the first substrate and the solidified first colloid;

[0011] Dotting a second colloid on the first colloid;

[0012] A second substrate is provided, and the second colloid is pressed by using the second substrate. Then, the second colloid is cured to combine the first colloid and the second colloid together.

[0013] As a further improvement of the present invention, the microstructure is a groove formed on the embossing side.

[0014] As a further improvement of the present invention, the first pressing side is planar, the first colloid after solidification has a first surface corresponding to the first pressing side, and in the step of "dotting the second colloid on the first colloid", the second colloid is dotted on the first surface.

[0015] As a further improvement of the present invention, in the step of "applying the first colloid on the stamping side", the first colloid is applied on the middle of the stamping side;

[0016] In the step of “dotting the second colloid on the first colloid”, the second colloid is dotted on the middle of the first surface.

[0017] As a further improvement of the present invention, the first colloid after solidification includes a first portion located in the plurality of grooves and a second portion extending outside the plurality of grooves, and a thickness of the second portion is less than a depth of the grooves.

[0018] As a further improvement of the present invention, the first colloid and the second colloid are both UV glue, and the first substrate, the second substrate and the anti-adhesion layer are all made of light-transmitting materials;

[0019] The step of “curing the first colloid” specifically includes: irradiating the first colloid with a UV light source to cure the first colloid, and when irradiating the first colloid, the UV light source is located on a side of the first substrate away from the imprinting side;

[0020] The step of “curing the second colloid” specifically includes: irradiating the second colloid with a UV light source to cure the second colloid, and when irradiating the second colloid, the UV light source is located on a side of the second substrate away from the imprinting side.

[0021] As a further improvement of the present invention, both the first substrate and the second substrate are made of glass material, and the anti-sticking layer is made of PET material.

[0022] As a further improvement of the present invention, the side of the second substrate pressing the second colloid is the second pressing side, and the second pressing side has an adhesion-promoting layer for adhering the second colloid.

[0023] As a further improvement of the present invention, the first pressing side has a plurality of convex surfaces matching the plurality of grooves, and when the first substrate presses the first colloid, the plurality of convex surfaces contact the first colloid and correspond one-to-one with the plurality of grooves.

[0024] As a further improvement of the present invention, the first substrate includes a substrate body and a prefilled layer provided on a side of the substrate body facing the stamping side, and the first pressing side is a side of the prefilled layer facing the stamping side.

[0025] Beneficial effects:

[0026] The microlens preparation method provided by the present invention is suitable for preparing microlenses with high sagittal height. In the method, a wafer is prepared by sequentially pressing a first colloid and a second colloid. The volume of the colloid required for each pressing is small, and the thickness of the colloid after pressing is also small. In addition, due to the provision of an anti-sticking layer, the first substrate will not adhere to the first colloid, thereby preventing the colloid from excessively diffusing during pressing and shrinking unevenly during curing, thereby ensuring that the surface accuracy of the microlens structure in the prepared wafer is high, and the thickness of the microlens structure at the center and the microlens structure at the periphery can be kept consistent. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic diagram of a method for preparing a microlens in the prior art;

[0028] Figure 2 for Figure 1 The enlarged schematic diagram of point A in the middle;

[0029] Figure 3 A schematic diagram of the process of preparing a microlens provided in the first embodiment of the present invention;

[0030] Figure 4-9 A schematic diagram of each step of a method for preparing a microlens provided in a first embodiment of the present invention;

[0031] Fig.10It is a front view of the second substrate and the chip in the first embodiment of the present invention;

[0032] Fig.11 A schematic front view of a first substrate used in a method for preparing a microlens according to a second embodiment of the present invention;

[0033] Figure 12-17 Schematic diagram of each step of a method for preparing a microlens provided in a second embodiment of the present invention.

[0034] In the figure:

[0035] 10. die; 11. embossing side; 12. groove; 13. anti-sticking layer;

[0036] 20. first colloid; 21. first surface; 22. first part; 23. second part;

[0037] 30. first substrate; 31. first pressing side; 32. anti-sticking layer; 33. convex surface; 34. substrate body; 35. pre-filling layer;

[0038] 40. Second colloid;

[0039] 50. second substrate; 51. second pressing side; 52. adhesion-promoting layer;

[0040] 60. Chip; 61. Microlens structure. DETAILED DESCRIPTION

[0041] The present invention will be described in detail below in conjunction with the embodiments shown in the accompanying drawings. However, the embodiments do not limit the present invention, and any changes in mechanism, method, or function made by a person skilled in the art according to the embodiments are all within the protection scope of the present invention.

[0042] The terms used herein, such as "upper", "lower", "left", "right", "front", "back", etc., which indicate relative spatial positions, are used for the purpose of convenience to describe the relationship between one feature and another feature as shown in the accompanying drawings. It is understood that, depending on the placement of the product, the terms of relative spatial positions may be intended to include different orientations other than those shown in the drawings, and should not be construed as limitations on the claims. In addition, the descriptor "horizontal" used herein is not completely equivalent to being perpendicular to the direction of gravity, and a certain angle of inclination is allowed.

[0043] An embodiment of the present invention provides a method for preparing a microlens, such as Figure 3-9 As shown, the method comprises the following steps:

[0044] S1, such as Figure 4As shown, a stamping die 10 is provided, one side of the stamping die 10 is an embossing side 11, and a plurality of microstructures matching the surface shape of the microlens are formed on the embossing side 11. In this embodiment, the microstructure is a groove 12 formed on the embossing side 11, and the specific structure of the groove 12 is designed according to the structure of the microlens, for example, the groove 12 can be hemispherical, and a plurality of grooves 12 are arranged in an array on the embossing side 11.

[0045] S2, such as Figure 5 As shown, at the point 11 on the stamping side, the first colloid 20 is in a non-solidified state and has a certain fluidity.

[0046] S3, such as Figure 6 As shown, a first substrate 30 is provided, and the first colloid 20 is pressed by the first substrate 30. The first substrate 30 presses the first colloid 20, flattens and spreads the first colloid 20, and fills at least part of the first colloid 20 into the plurality of grooves 12. After the first substrate 30 presses the first colloid 20, the first colloid 20 is solidified to convert the first colloid 20 from a non-solidified state to a solidified state. The side of the first substrate 30 that presses the first colloid 20 is a first pressing side 31, and the first pressing side 31 has an anti-sticking layer 32 for preventing the first colloid 20 from sticking.

[0047] S4, such as Figure 7 As shown, the first substrate 30 and the cured first colloid 20 are separated. As described above, since the first pressing side 31 has the anti-sticking layer 32 for preventing the first colloid 20 from sticking, the first substrate 30 and the cured first colloid 20 can be easily separated.

[0048] S5, such as Figure 8 As shown, the second colloid 40 is dotted on the first colloid 20. The second colloid 40 is in a non-solidified state and has a certain fluidity.

[0049] S6, such as Fig. 9 As shown, a second substrate 50 is provided, and the second colloid 40 is pressed by the second substrate 50. The second colloid 40 is pressed by the second substrate 50, and the second colloid 40 is flattened and spread out so that the second colloid 40 can fully contact the first colloid 20. After the second substrate 50 presses the second colloid 40, the second colloid 40 is cured so that the second colloid 40 is converted from a non-solidified state to a solidified state. The cured first colloid 20 and the second colloid 40 can be combined together.

[0050] It should be noted that the above reference numerals S1-S6 do not strictly represent the execution order of the above steps.

[0051] like Fig.10As shown, the whole colloid formed by combining the first colloid 20 and the second colloid 40 can be called a wafer 60. The wafer 60 has a plurality of microlens structures 61 formed by a plurality of grooves 12. In subsequent steps, the wafer 60 can be cut to obtain a plurality of individual microlenses.

[0052] The above method is suitable for preparing microlenses with high sagittal height. In the above method, the chip 60 is prepared by sequentially pressing the first colloid 20 and the second colloid 40. The volume of the colloid required for each pressing is small, and the thickness of the colloid after pressing is also small. In addition, due to the provision of the anti-sticking layer 32, the first substrate 30 will not adhere to the first colloid 20, thereby preventing the colloid from excessively diffusing during pressing and shrinking unevenly during curing. In this way, it can be ensured that the surface accuracy of the microlens structure 61 in the prepared chip 60 is high, and the thickness of the microlens structure 61 at the center and the microlens structure 61 at the periphery can be kept consistent.

[0053] In the above step S2, the first colloid 20 can be applied to the middle of the stamping side 11. The applied first colloid 20 can be in a bulge shape with a high middle and low edges on the stamping side 11. When the first substrate 30 is subsequently used to press the first colloid 20, the first colloid 20 spreads from the middle of the stamping side 11 to the surrounding areas and can be fully filled into the multiple grooves 12.

[0054] In this embodiment, the first pressing side 31 is in a planar shape. Since the first colloid 20 is pressed by the first pressing side 31, the first colloid 20 after solidification has a first surface 21 corresponding to the first pressing side 31. In the step of "applying the second colloid 40 on the first colloid 20", the second colloid 40 is applied on the first surface 21. Specifically, the second colloid 40 is applied in the middle of the first surface 21. The applied second colloid 40 is in a bulge shape with a high middle and low edges on the first surface 21. When the second substrate 50 is used to press the second colloid 40 later, the second colloid 40 spreads out from the middle of the first surface 21 to the surroundings. Since the first pressing side 31 is in a planar shape, the first surface 21 is also roughly in a planar shape. When the second colloid 40 is pressed, it spreads out on the planar second surface. The solidified second colloid 40 will be in a flat plate shape. After the second colloid 40 is pressed by the second substrate 50, its thickness is relatively thin, so when solidified, the overall shrinkage is relatively small.

[0055] In this embodiment, the solidified first colloid 20 includes a first portion 22 located in the plurality of grooves 12 and a second portion 23 extending outside the plurality of grooves 12. The thickness of the second portion 23 is less than the depth of the grooves 12. Thus, during the first pressing, the required volume of the first colloid 20 can be maintained at an appropriate value.

[0056] In this embodiment, the first colloid 20 and the second colloid 40 are both UV glues, and the first colloid 20 and the second colloid 40 can be transformed from a non-solidified state to a solidified state by irradiating the first colloid 20 and the second colloid 40 with UV light. The first substrate 30, the second substrate 50 and the anti-adhesion layer 32 are all made of light-transmitting materials.

[0057] The above step of "curing the first colloid 20" specifically includes: irradiating the first colloid 20 with a UV light source (not shown in the figure) to cure the first colloid 20. When irradiating the first colloid 20, the UV light source is located on the side of the first substrate 30 away from the imprinting side 11, and the UV light emitted by the UV light source passes through the first substrate 30 and the anti-adhesion layer 32 to irradiate the first colloid 20, thereby curing the first colloid 20. In the case where the UV light source is located above the first substrate 30, the first colloid 20 is gradually cured from top to bottom, and the curing process starts from the surface of the first colloid 20 and gradually advances to the inside. Due to the setting of the anti-adhesion layer 32, the first substrate 30 has no adhesion to the first colloid 20. When the first colloid 20 of the lower layer is cured, the first colloid 20 of the upper layer that has been cured can also shrink with the glue of the lower layer. In this way, the contraction values ​​of various parts of the first colloid 20 are consistent during curing, and the surface accuracy of the microlens structure 61 after curing is high.

[0058] The above step of "curing the second colloid 40" specifically includes: irradiating the second colloid 40 with a UV light source to cure the second colloid 40. When irradiating the second colloid 40, the UV light source is located on the side of the second substrate 50 away from the imprint side 11. The UV light emitted by the UV light source irradiates the second colloid 40 through the second substrate 50, thereby curing the second colloid 40. When the UV light source is located above the first substrate 30, the second colloid 40 is gradually cured from top to bottom. The second colloid 40 and the first colloid 20 are made of the same material. After curing, the second colloid 40 can be combined with the first colloid 20.

[0059] Specifically, the first substrate 30 and the second substrate 50 are both made of glass material to have good light transmittance. The anti-adhesion layer 32 is made of PET material. The anti-adhesion layer 32 of PET material has no adhesion to the first colloid 20 and has good light transmittance. The UV light emitted by the UV light source has less loss when passing through the anti-adhesion layer 32.

[0060] like Figure 9-10 As shown, the side of the second substrate 50 pressing the second colloid 40 is the second pressing side 51, and the second pressing side 51 has an adhesion-promoting layer 52 for adhering the second colloid 40. The adhesion-promoting layer 52 will adhere the second adhesive layer and the second substrate 50 together, that is, after completing the above step S6, the second substrate 50 will be adhered to the wafer 60, and the second substrate 50 can carry the wafer 60, so that the wafer 60 can be processed in other ways in subsequent steps.

[0061] As described above, after being pressed by the second substrate 50, the second colloid 40 is thinner, so even if the second substrate 50 adheres to the second colloid 40, the shrinkage inconsistency between the upper second colloid 40 and the lower second colloid 40 during curing can be controlled within a smaller range.

[0062] like Figure 1 As shown, in this embodiment, the stamping side 11 is provided with an anti-sticking layer 13 for preventing the first colloid 20 from sticking. The provision of the anti-sticking layer 13 enables the first colloid 20 to be easily separated from the stamping mold 10 .

[0063] The second embodiment of the present invention further provides a method for preparing a microlens. The difference between this embodiment and the first embodiment is that: Fig.11 , 14 As shown, in this embodiment, the first pressing side 31 has a plurality of convex surfaces 33 matching the plurality of grooves 12, and the plurality of convex surfaces 33 are arranged in an array on the first pressing side 31. When the first substrate 30 presses the first colloid 20, the plurality of convex surfaces 33 contact the first colloid 20 and correspond one to one with the plurality of grooves 12. Under the action of the convex surfaces 33 and the grooves 12, when the first substrate 30 presses the first colloid 20, a wavy structure corresponding to the plurality of grooves 12 is formed on the first colloid 20. At the wavy structure, the thickness of the first colloid 20 is small. Therefore, when the first colloid 20 is cured, its shrinkage is more controllable. After the curing is completed, the surface shape of the microlens structure 61 is more precise.

[0064] like Fig.13 As shown, the cured first colloid 20 has a first surface 21 corresponding to the first pressing side 31, and a plurality of pits formed by pressing the convex surface 33 are formed on the first surface 21. In the step of "dotting the second colloid 40 on the first colloid 20", the second colloid 40 is dotted on the first surface 21, and when the second substrate 50 presses the second colloid 40, at least part of the second colloid 40 will fill the plurality of pits.

[0065] The first substrate 30 comprises a substrate body 34 and a prefilled layer 35 disposed on the side of the substrate body 34 facing the imprinting side 11. The first pressing side 31 is the side of the prefilled layer 35 facing the imprinting side 11. The substrate body 34 can be made of a light-transmitting material such as glass, and the prefilled layer 35 can be made of a light-transmitting colloid material.

[0066] like Figure 12-17 As shown, the steps of the microlens manufacturing method in this embodiment are the same as those of the microlens manufacturing method in the first embodiment, and will not be described in detail here.

[0067] The microlens prepared by the microlens preparation method in the above embodiment is a convex lens. In other embodiments, the above microstructure may also be a convex portion formed on the stamping side. In this way, the microlens prepared by the microlens preparation method is a concave lens. Correspondingly, the first pressing side 31 has a plurality of concave surfaces matching the plurality of convex portions. When the first substrate 30 presses the first colloid 20, the plurality of concave surfaces contact the first colloid 20 and correspond one-to-one with the plurality of convex portions.

[0068] It should be understood that although the present specification is described according to embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0069] The above embodiments are only used to illustrate the technical solution of the present application and are not intended to limit it. Although the present application has been described in detail with reference to the preferred embodiments, a person skilled in the art should understand that the technical solution of the present application may be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present application.

Claims

1. A method for preparing a microlens, characterized in that: The steps include: Providing a stamping die, one side of the stamping die being a stamping side, and the stamping side being formed with a plurality of microstructures matching the surface shape of the microlens; Applying a first colloid on the stamping side; Providing a first substrate, using the first substrate to press the first colloid, and then curing the first colloid, the side of the first substrate where the first colloid is pressed is a first pressing side, and the first pressing side has an anti-sticking layer for preventing the first colloid from sticking; separating the first substrate and the solidified first colloid; Dotting a second colloid on the first colloid; A second substrate is provided, and the second colloid is pressed by using the second substrate. Then, the second colloid is cured to combine the first colloid and the second colloid together.

2. The method for preparing a microlens according to claim 1, characterized in that: The microstructures are grooves formed on the stamped side.

3. The method for preparing a microlens according to claim 2, characterized in that: The first pressing side is planar, the first colloid after solidification has a first surface corresponding to the first pressing side, and in the step of "dotting the second colloid on the first colloid", the second colloid is dotted on the first surface.

4. The method for preparing a microlens according to claim 3, characterized in that: In the step of "applying the first colloid on the stamping side", the first colloid is applied on the middle of the stamping side; In the step of “dotting the second colloid on the first colloid”, the second colloid is dotted on the middle of the first surface.

5. The method for preparing a microlens according to claim 2, characterized in that: The first colloid after solidification includes a first portion located in the plurality of grooves and a second portion extending outside the plurality of grooves, wherein a thickness of the second portion is smaller than a depth of the grooves.

6. The method for preparing a microlens according to claim 1, characterized in that: The first colloid and the second colloid are both UV glue, and the first substrate, the second substrate and the anti-sticking layer are all made of light-transmitting materials; The step of "curing the first colloid" specifically includes: irradiating the first colloid with a UV light source to cure the first colloid, and when irradiating the first colloid, the UV light source is located on a side of the first substrate away from the imprinting side; The step of “curing the second colloid” specifically includes: irradiating the second colloid with a UV light source to cure the second colloid, and when irradiating the second colloid, the UV light source is located on a side of the second substrate away from the imprinting side.

7. The method for preparing a microlens according to claim 5, characterized in that: The first substrate and the second substrate are both made of glass, and the anti-sticking layer is made of PET.

8. The method for preparing a microlens according to claim 1, characterized in that: The side of the second substrate where the second colloid is pressed is a second pressing side, and the second pressing side has an adhesion-promoting layer for adhering the second colloid.

9. The method for preparing a microlens according to claim 2, characterized in that: The first pressing side has a plurality of convex surfaces matching the plurality of grooves. When the first substrate presses the first colloid, the plurality of convex surfaces contact the first colloid and correspond one-to-one with the plurality of grooves.

10. The method for preparing a microlens according to claim 9, characterized in that: The first substrate includes a substrate body and a prefilling layer provided on a side of the substrate body facing the stamping side, and the first pressing side is a side of the prefilling layer facing the stamping side.

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