Microlens master mold manufacturing method and microlens master mold

Abstract

The present invention discloses a method for manufacturing a microlens master mold and a microlens master mold, comprising: applying a photoresist on a substrate; photoetching a pattern on the photoresist to form a photoetching window; electroplating a predetermined metal within the photoetching window to form a metal pillar; wherein the diameter of the photoetching window is equal to the diameter of the metal pillar; removing the photoresist; subjecting the metal pillar to a high-temperature vacuum reflow treatment to form a metal hemisphere; and cooling and curing the metal hemisphere to obtain the microlens master mold. The present invention not only simplifies the manufacturing process but also enables the use of conventional semiconductor processing techniques to achieve high-precision, high-density, and high-duty-cycle microlens master molds, significantly reducing production costs. Furthermore, electroplating and high-temperature vacuum reflow techniques can be used to make the metal hemisphere's surface as smooth as a mirror, significantly reducing its roughness and achieving ultra-low roughness manufacturing. Furthermore, the method is easy to clean and regenerate, making it suitable for the manufacture of various microlens master molds and having a wide range of applicability.

Description

Technical Field

[0001] The present invention relates to the technical field of microlenses, and in particular to a method for manufacturing a microlens master mold and the microlens master mold. Background Art

[0002] Microlens array devices are increasingly used in focal plane light collection, laser collimation, large area array displays, light efficiency enhancement, optical computing, optical interconnection and micro scanning, and their manufacturing methods and processes have been increasingly studied in depth.

[0003] Currently, the manufacturing method for microlens array devices involves first using a lens master mold to create a casting mold or hot-pressing mold, then casting or hot-pressing a resin material onto the casting mold or hot-pressing mold to form the resin lens. During the development of this invention, technical researchers discovered that the existing lens master molds are made using a milling and forging process, which requires repeated machining, is complex, and expensive. Summary of the Invention

[0004] In view of this, embodiments of the present invention provide a method for manufacturing a microlens master mold and a microlens master mold to solve the above technical problems.

[0005] An embodiment of the present invention provides a method for manufacturing a microlens master mold, comprising: coating a photoresist on a substrate; photoetching a pattern on the photoresist to form a photoetching window; electroplating a predetermined metal in the photoetching window to form a metal pillar; wherein the diameter of the photoetching window is equal to the diameter of the metal pillar; removing the photoresist; performing a high-temperature vacuum reflow treatment on the metal pillar to form a metal hemisphere; and cooling and curing the metal hemisphere to obtain a microlens master mold.

[0006] Optionally, coating the photoresist on the substrate includes: depositing a metal connection layer on the substrate; and coating the photoresist on the metal connection layer.

[0007] Optionally, depositing the metal connection layer on the substrate includes: depositing a metal adhesion layer on the substrate; and depositing an anti-diffusion layer on the metal adhesion layer to form the metal connection layer.

[0008] Optionally, after removing the photoresist, the method includes performing plasma cleaning to remove residual photoresist.

[0009] Optionally, after removing the residual photoresist, the method further includes: etching the metal connection layer to remove the metal connection layer between adjacent metal pillars.

[0010] The present invention also provides a microlens master mold manufactured according to the above-mentioned microlens master mold manufacturing method, which includes: a substrate and at least one row of metal hemispheres, each row of metal hemispheres including at least one metal hemisphere, and the metal hemispheres are fixed on the substrate.

[0011] Optionally, a metal connection layer is further included, the metal hemispheres correspond to the metal connection layers one-to-one, and the metal hemispheres are fixed on the substrate through the metal connection layers.

[0012] Optionally, the metal connection layer includes a metal adhesive layer and an anti-diffusion layer, the metal adhesive layer is deposited on the substrate, the anti-diffusion layer is deposited on the metal adhesive layer, and the metal hemisphere is arranged on the anti-diffusion layer.

[0013] Optionally, the thickness of the anti-diffusion layer is ten times the thickness of the metal bonding layer.

[0014] Optionally, the metal hemisphere is made of a low-melting-point metal or alloy with a melting point lower than 500°C.

[0015] The microlens master mold manufacturing method and the microlens master mold provided in the embodiments of the present invention include providing a photoresist on a substrate, forming a photolithography window through a photolithography process, electroplating a predetermined metal in the photolithography window to form a metal column, subjecting the metal column to high-temperature reflow to obtain a metal hemisphere, and cooling and curing the metal hemisphere to obtain the microlens master mold. This method not only simplifies the manufacturing process but also enables the use of conventional semiconductor processing techniques to achieve high-precision, high-density, and high-duty-cycle microlens master molds, significantly reducing production costs. Furthermore, electroplating and high-temperature vacuum reflow techniques can be used to make the surface of the metal hemisphere as smooth as a mirror, significantly reducing the roughness of the metal hemisphere and achieving ultra-low roughness manufacturing. Furthermore, the method is easy to clean and regenerate, and is adaptable to the manufacture of various microlens master molds, with wide applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 4 is a flow chart of a method for manufacturing a microlens master mold according to an embodiment of the present invention.

[0017] Figure 2 FIG. 4 is a schematic diagram of a method for manufacturing a microlens master mold according to another embodiment of the present invention.

[0018] Figure 3 Schematic diagram of the structure of a microlens master mold according to an embodiment of the present invention.

[0019] Figure 4 yes Figure 2 A magnified view of the middle panel.

[0020] Figure 5 4 is a cross-sectional view of a microlens master mold according to an embodiment of the present invention.

[0021] Figure 6 yes Figure 5 Magnified view of B. DETAILED DESCRIPTION

[0022] The technical solution of the present invention is described in detail below with reference to the accompanying drawings and specific embodiments. Identical components are denoted by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "up," and "down" used in the following description refer to directions in the accompanying drawings, while the terms "inward" and "outward" refer to directions toward or away from the geometric center of a particular component, respectively.

[0023] Figure 1 FIG. 1 shows a flow chart of a method for manufacturing a microlens master mold according to an embodiment of the present invention. Figure 1 As shown, the method for manufacturing a microlens master mold provided by an embodiment of the present invention includes:

[0024] S110, coating a photoresist on the substrate;

[0025] The substrate can be made of materials such as silicon, glass, and ceramics.

[0026] S120, photolithographically patterning the photoresist to form a photolithographic window;

[0027] like Figure 2 As shown, a pattern is photoetched on the photoresist 6 using an existing photolithography process to form a photolithography window 7 of a predetermined size.

[0028] S130, electroplating a predetermined metal in the photolithography window to form a metal pillar; wherein the diameter of the photolithography window is equal to the diameter of the metal pillar;

[0029] In this embodiment, the predetermined metal is a low melting point metal or alloy with a melting point lower than 500° C. For example, alloys such as gold-tin, tin-lead, tin-silver-copper, tin-silver, indium-tin, or metals such as indium, tin, and aluminum.

[0030] Preferably, the predetermined metal is gold-tin or tin-lead alloy, which can form a metal hemisphere with a smooth surface at the reflow temperature, forming a metal hemisphere with an excellent smooth surface.

[0031] According to the size of the metal hemisphere required by the microlens master mold, a predetermined metal of a preset height is electroplated. Since the volume of the metal hemisphere 1 is equal to the volume of the metal pillar 8, the volume and height of the metal hemisphere can be precisely controlled by precisely controlling the height of the metal pillar 8.

[0032] In this embodiment, the metal pillar 8 is a cylinder, and the photolithography window 7 is a circle. The cylinder and the photolithography window 8 are coaxial.

[0033] S140, removing the photoresist;

[0034] In this embodiment, a stripping process is adopted to strip the photoresist 6 to remove the photoresist 6 .

[0035] S150, performing a high-temperature vacuum reflow treatment on the metal pillar to form a metal hemisphere;

[0036] During the high-temperature vacuum reflow of the metal pillars 8, different high-temperature temperatures and vacuum levels can be set according to the desired metal, thereby precisely controlling the high-temperature temperature and vacuum level to prevent oxidation of the metal pillars 8, thereby forming a metal hemisphere with an excellent surface finish. The high-temperature vacuum reflow can utilize existing high-temperature vacuum reflow technology.

[0037] In this embodiment, the high temperature is a temperature capable of melting a predetermined metal, and the metal hemisphere 1 is half of a sphere.

[0038] S160, the metal hemisphere is cooled and solidified to obtain a microlens mother mold.

[0039] like Figure 3 As shown, after cooling, the metal hemisphere 1 solidifies to obtain a microlens master mold.

[0040] The microlens master mold manufacturing method provided by an embodiment of the present invention comprises providing a photoresist on a substrate, forming a photolithography window through a photolithography process, electroplating a predetermined metal within the photolithography window to form a metal pillar, subjecting the metal pillar to high-temperature reflow to obtain a metal hemisphere, and then cooling and curing the metal hemisphere to obtain a microlens master mold. This method not only simplifies the manufacturing process but also enables the use of conventional semiconductor processing techniques to achieve high-precision, high-density, and high-duty-cycle microlens master molds, significantly reducing production costs. Furthermore, electroplating and high-temperature vacuum reflow techniques can be used to make the surface of the metal hemisphere as smooth as a mirror, significantly reducing the roughness of the metal hemisphere and achieving ultra-low roughness manufacturing. Furthermore, the method is easy to clean and regenerate, and is adaptable to the manufacture of various microlens master molds, with wide applicability.

[0041] The microlens master mold produced by the microlens master mold manufacturing method provided in this embodiment of the present invention can reduce the surface finish of the metal hemispheres after long-term use. Semiconductor cleaning, remelting, and metal reduction can be used to regenerate the metal hemispheres, further reducing production costs. In this embodiment, the diameter of the metal hemispheres 1 can range from several microns to several millimeters.

[0042] The manufacturing method of the microlens master mold of the present invention is now described by taking the specific manufacturing process of a microlens master mold as an example. Figure 2 As shown, the details are as follows:

[0043] S200, selecting a substrate;

[0044] In this embodiment, the substrate 2 is in the shape of a circular plate.

[0045] S210, depositing a metal connection layer on the substrate;

[0046] The metal connection layer 3 is deposited on the substrate 1 using an existing deposition process.

[0047] In this embodiment, the material of the metal connection layer 3 can be titanium, nickel, chromium, molybdenum, aluminum, tantalum and other metals, or gold-titanium, tantalum-titanium, tungsten-titanium, nickel-titanium, tantalum-chromium, nickel-chromium, tungsten-chromium, palladium-titanium, palladium-chromium and other alloys.

[0048] Preferably, the metal connection layer 3 is made of gold-titanium alloy to better bond the metal hemisphere 1 .

[0049] S220, coating a photoresist on the metal connection layer;

[0050] like Figure 2 As shown, the metal connection layer 3 is provided on one of the plate surfaces and the circumferential end surface of the substrate 1 in order to better coat the photoresist 6 .

[0051] S230: photolithography patterns are formed on the photoresist to form photolithography windows;

[0052] S240, electroplating a predetermined metal to a predetermined height according to the size of the metal hemisphere of the desired microlens mother mold;

[0053] S250, performing a film stripping process to remove the photoresist;

[0054] S260, performing plasma cleaning to remove residual photoresist;

[0055] The residual photoresist is cleaned using existing plasma cleaning technology.

[0056] S270, etching the metal connection layer to remove the metal connection layer between adjacent metal pillars;

[0057] In this embodiment, the metal connection layer 3 may be removed by using an existing etching process.

[0058] S280, performing a high-temperature vacuum reflow treatment on the metal pillar to form a metal hemisphere;

[0059] S290, the metal hemisphere is cooled and solidified to obtain a microlens mother mold.

[0060] The microlens master mold manufacturing method provided by the embodiment of the present invention can ensure the connection security of the metal hemispheres by providing a metal connection layer on the substrate, and remove the metal connection layer between adjacent metal pillars through an etching process. At the same time, the photoresist can be completely removed through film stripping and plasma cleaning to ensure the cleanliness of the microlens master mold, ensure better molding of the metal hemispheres, and ensure a smooth surface.

[0061] In a specific embodiment of the present invention, Figure 4 As shown, S210 further includes:

[0062] S211, depositing a metal bonding layer 4 on the substrate 2 using a deposition process;

[0063] S212 , depositing an anti-diffusion layer 5 on the metal bonding layer 4 .

[0064] By configuring the metal connection layer 4 as the anti-diffusion layer 5 and the metal adhesive layer 4, the connection firmness of the metal hemisphere 1 is ensured while preventing the metal hemisphere 1 from diffusing into the metal connection layer 3 or the substrate 2, thereby further ensuring the formed ball diameter of the metal hemisphere 1 and the smoothness of adjacent metal hemispheres 1.

[0065] Furthermore, the thickness of the anti-diffusion layer 5 is greater than that of the metal bonding layer 4 , so as to better prevent the metal hemisphere 1 from diffusing into the metal connection layer 3 or the substrate 2 .

[0066] Preferably, the thickness of the anti-diffusion layer 5 is ten times the thickness of the metal bonding layer 4 , which can further prevent the metal hemisphere 1 from diffusing into the metal connection layer 3 or the substrate 2 .

[0067] Furthermore, the thickness of the anti-diffusion layer is 480-510 nanometers, and the thickness of the metal bonding layer is 480-510 nanometers.

[0068] In this embodiment, the thickness of the anti-diffusion layer 5 is about 500 nanometers, and the thickness of the metal bonding layer 4 is about 50 nanometers.

[0069] Furthermore, the anti-diffusion layer 5 is made of gold, and the metal bonding layer 4 is made of titanium to save costs.

[0070] Based on the above-mentioned method for manufacturing a microlens master mold, an embodiment of the present invention further provides a microlens master mold, such as Figure 3 As shown, it includes: a substrate 1 and at least one row of metal hemispherical parts.

[0071] Each row of metal hemispheres includes at least one metal hemisphere 1, the bottom surface of which is fixed on the substrate 2. The bottom surface is a circular surface with a radius equal to the diameter of the sphere.

[0072] exist Figure 3 In the embodiment, multiple rows of metal hemispherical portions are provided on the substrate 1, and a gap exists between two adjacent rows of metal hemispherical portions.

[0073] Preferably, the spacing between two adjacent rows of metal hemispherical portions is equal to facilitate the arrangement of the metal hemispherical portions.

[0074] like Figure 5 As shown, each row of metal hemisphere portions includes a plurality of metal hemispheres 1 , with gaps between adjacent metal hemispheres 1 .

[0075] Preferably, the spacing between adjacent metal hemispheres 1 is equal, which further facilitates the arrangement of the metal hemispheres 1 .

[0076] Preferably, the spacing between adjacent metal hemispheres 1 is equal to the spacing between two adjacent rows of metal hemispheres, which can further facilitate the arrangement of the metal hemispheres 1 .

[0077] Furthermore, if Figure 6 As shown, the microlens master mold further includes a metal connection layer 3 , and the metal hemispheres 1 correspond one to one with the metal connection layer 3 . The metal hemispheres 1 are fixed on the substrate 1 through the metal connection layer 3 to ensure the connection firmness of the metal hemispheres 1 .

[0078] In a preferred embodiment, the distance between adjacent metal hemispheres 1 is equal to the diameter of the metal hemispheres 1 , which not only facilitates the arrangement of the metal hemispheres 1 but also allows for more metal hemispheres 1 to be added as much as possible, thereby reducing production costs.

[0079] The microlens master mold provided by the embodiments of the present invention comprises a process of disposing a photoresist on a substrate, forming a photolithography window through a photolithography process, electroplating a predetermined metal within the photolithography window to form a metal pillar, subjecting the metal pillar to high-temperature reflow to obtain a metal hemisphere, and then cooling and solidifying the metal hemisphere. This not only simplifies the manufacturing process but also enables the use of conventional semiconductor processing techniques to achieve high-precision, high-density, and high-duty-cycle microlens master molds, significantly reducing production costs. Furthermore, electroplating and high-temperature vacuum reflow techniques can be used to make the surface of the metal hemisphere as smooth as a mirror, significantly reducing the roughness of the metal hemisphere and achieving ultra-low roughness manufacturing. Furthermore, the microlens master mold is easy to clean and regenerate, and is adaptable to the manufacture of various microlens master molds, with wide applicability.

[0080] The technical solution of the present invention has been described in detail above with reference to specific embodiments. The specific embodiments described are intended to help understand the concept of the present invention. Derivations and modifications made by those skilled in the art based on the specific embodiments of the present invention also fall within the scope of protection of the present invention.

Claims

1. A method for manufacturing a microlens master mold, characterized in that: include: applying photoresist on the substrate: depositing a metal adhesion layer on the substrate; depositing an anti-diffusion layer on the metal bonding layer to form a metal connection layer; coating a photoresist on the metal connection layer; Photoetching a pattern on the photoresist to form a photoetching window; Electroplating a predetermined metal in the photolithography window to form a metal column; wherein the diameter of the photolithography window is equal to the diameter of the metal column, and the predetermined metal is gold-tin or tin-lead alloy; Removing photoresist; The metal column is subjected to high-temperature vacuum reflow treatment to form a metal hemisphere; The metal hemisphere is cooled and solidified to obtain a microlens mother mold.

2. The method for manufacturing a microlens master mold according to claim 1, wherein: After removing the photoresist, it includes: Perform plasma cleaning to remove residual photoresist.

3. The method for manufacturing a microlens master mold according to claim 2, wherein: After removing the residual photoresist, it also includes: The metal connection layer is etched to remove the metal connection layer between adjacent metal pillars.

4. A microlens master mold manufactured according to the method for manufacturing a microlens master mold according to any one of claims 1 to 3, characterized in that: include: A substrate and at least one row of metal hemisphere portions, each row of metal hemisphere portions including at least one metal hemisphere, the metal hemisphere being fixed on the substrate, and a metal connection layer, the metal hemisphere corresponding one-to-one with the metal connection layer, the metal hemisphere being fixed on the substrate via the metal connection layer, the metal connection layer including a metal bonding layer and an anti-diffusion layer, the metal bonding layer being deposited on the substrate, the anti-diffusion layer being deposited on the metal bonding layer, and the metal hemisphere being arranged on the anti-diffusion layer.

5. The microlens master mold according to claim 4, wherein: The thickness of the anti-diffusion layer is ten times the thickness of the metal bonding layer.

6. The microlens master mold according to claim 4 or 5, wherein: The metal hemisphere is made of a low-melting-point metal or alloy with a melting point lower than 500°C.

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