TWI283655B - Method for producing microlens array by using flexible mold - Google Patents

Abstract

A method for producing a microlens array by using a flexible mold comprises performing a pressure variation procedure on a flexible mold having a flexible membrane for forming an internal chamber to produce a deformation on the curvature of the membrane; and using a curable polymer material to replicate the shape thereof so that the flexible mold can produce a microlens array with a different radius of curvature and focal length by using a different pressure in order to endow the microlens array with focusing and photo-sensing functions. Since the formation process of the microlens array is free of thermal melting, the shape and the dimension of the microlens can be controlled stably. Furthermore, an electro-casting formation mold is used for mass-production, thereby achieving a low production device cost and a stable process.

Description

1283655 V. INSTRUCTION DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to a method of applying a deflection method, and more specifically, a flexible mold of a square lens of a broken lens array. Pressure: 曰: 3 using a flexible film and a cavity polymer cured material deformation, and then using different pressure control to create a different curvature half ... over concave lens array method. ^, ",, 彳 凸 凸 或 或 or micro [previous technology] Whether it is liquid crystal display (LCD), mobile phone assistant (m), need brighter, more durable, more screen-like light source to enhance the display effect When microlens array technology is used, it has been pointed out that it can be improved by 25% ns. It can also be applied to other optical or military fields. In addition, conventional microlens arrays have various manufacturing methods, one of which is common. For example, in our Patent Publication No. 5 1 9578, "Manufacturing Method of Integrated Microsphere Lens Fiber Switching Device", using a lithography and a remnant process, a lens u 疋 thickness = a resist layer is formed on a substrate, and Using a mask to define the molding area on the thick film photoresist =, and then removing the lens carrier layer and the thick layer outside the molding area to form a columnar microstructure, and then passing the high temperature crucible to make the columnar microstructure Melting, and by cohesive force 盥 surface step force η, the micro-convex cylinders can be automatically condensed into hemispherical microlenses;

1283655 V. DESCRIPTION OF THE INVENTION (2) [Summary of the Invention] The radius of curvature of the microlens can be controlled by the thickness of the thickness of the film and the diameter of the lens. However, the control of the hemispherical surface is difficult to accurately control, so the whole The process is unstable, so there is still room for improvement. The present invention provides a method for manufacturing a microlens array by using a flexural mold by using a flexible film having a flexible film and a flexible mold for forming an inner cavity, and deforming the curvature of the film by pressure change, and using a curable high The molecular material transforms its shape so that the flexural mold can be used with different pressure control to produce microlens arrays with different radii of curvature and focal length to achieve focus and sensitization. The method for manufacturing a microlens array by using a flexible mold of the present invention can be mainly used to solve the defects that the conventional molding method is complicated and the height of a single lens is limited, and secondly, the process can be stabilized, and different curvature radius and focal length can be accurately manufactured. A micro-convex lens array or a micro-concave lens array, and finally, can be re-formed into a mold set, making it suitable for mass production. [Embodiment] Please refer to the first figure, which is a schematic diagram of a structural change caused when a film structure is subjected to a uniform pressure difference, that is, when the film structure a is subjected to a uniform pressure P2 and P1 respectively and the P2 is larger than When p 1 , the film structure a is deformed in the outer direction to be in the form of a microlens, which is a basic principle that must be used in the formation of the microlens array of the present invention, and is hereby described. Please refer to the second and third figures, the invention is a method of applying a flexible mold 1283655

The method for making a microlens array comprises the following steps: (1) Fabrication of a flexural mold a, pre-preparing a wafer substrate 1 1, and applying yellow light lithography such as photoresist coating, exposure and development on the substrate The technique produces a SU2 array of SU-8 photoresist structure layers 爪2 with a thick claw shape to form a photoresist mold 10; b 2 PDMS?K compound 2 〇 (system polydimethy -^." The abbreviation of the polymer is applied to the structural layer 12 of the photoresist mold at 600 revolutions per minute (rpm); c, finally, at 150. 〇, 15 minutes hot-baked mixture of PDMS polymer 2 and curing agent to cure the PDMS polymer 20; "d, demold the cured PDMS polymer 20 from the photoresist mold 丄0 to form a flex mold 30, the flexural mold 3 〇 is opposite to the photoresist mold 丄〇 each photoresist structure layer 12 is formed with a recessed groove 3 1 , and a flexible film structure is formed at the bottom of each recessed groove 31 After layer 3 2 'after 'the direction of the recessed groove 3 1 of the flexible mold 30 is treated with 3 watts of oxygen plasma for 30 seconds' and bonded to a glass substrate 4 ,, so that the mold 3 0 The recessed groove 3 1 under each of the film structure layers 3 2 can be densely formed to form an inner cavity 33. '(2) The micro lens array is rotated a, and the film structure layer 3 2 of the flexible mold 30 is coated. The cloth can be cured back into a sub-material. In this embodiment, a UV-curable adhesive is used as the curable $eight material, and a curable high-divided gentleman layer 50 is formed on the flexural mold 30, and the flexible layer is formed. Mold 30, glass substrate 4 and can be fixed

1283655 5 invention description (4) ^ substructure layer 5 〇 placed together in a ring; 6 0 top with - can be pressure gram through the "material ^, the environmental cavity" sealed, and connected inside the environmental cavity 60; Ming cover 6 1 2 control the environment cavity 6 ◦ inside: Pu 7 cavity 3 3 : 3 ϊΠ 60 internal pressure is greater than the flex mold 3 〇 2 will ί = the flexural mold 3 〇 film structure layer 3 uncured: A concave shape is formed by inward depression, and the upper surface is recorded: on the contrary, the solid molecular structure layer 50 is deformed by the shape of the convex structure, and the pressure is less than: the fourth picture is shown, when the environmental cavity 60 forms a negative inside. When the pressure or the mold and the q ^ 70 type mold 3 are within the internal pressure of the inner cavity 3 3 , the flexible film structural layer 32 is also convexly convex by the pressure difference, so that the coating is not applied thereto. The cured curable polymer structure layer 5 U is deformed in a concave shape; c. is irradiated by the ultraviolet light source 80 from above the transparent cover 61, so that the ultraviolet light penetrates the acrylic transparent cover 6 1 It is irradiated onto the uv curable adhesive of the curable polymer structure layer 5 to be cured, and then the cured high score can be cured. Structural layer 5 billion 'release, which can be in the microlens array or lenticular dimples lenticular plate 51 is formed of a flexible mold 30 of the turning system. Further, after the microlens array 51 is formed, it can be converted into a metal mold by electroforming process for injection molding and mass production. Regarding the experiment of the present invention, the assembly method is as shown in the third figure, and the experiments are sequentially performed at pressure differences of 10, 20, 30, 40, 50, 60, 70 KPa, respectively, and the relevant conditions are as shown in FIG. , can be calculated by the following formula (1)

Page 8 1283655 V. Description of the invention (5) The height h of the lens is taken out, after which the surface contour of each microlens is regarded as the surface of the sphere 'using the measured lens height h and diameter d, and the refractive index of the photoresist layer itself Rate n (refractive index), and through the following formulas (2) and (3), the radius of curvature of the lens rc (radius of curvature) and the focal length f (focus) can be calculated, as shown in the data of the fifth figure (1) (2)

Rc =- 2k and

Rc «-1 (3) Furthermore, 1 · the array or the concave radius and focal length of the hair array, the height of the sheet is limited to 2 · The hair changes and controls the shape of the thin lens and 3 · The hair device, plus the available Low equipment cost The advantages of the flexible mirror array of the present invention can be effectively solved and the like. Ming's flexible film structure layer 3 size, so it does not need to be complicated by electroforming and process stability points and the achievable functions are summarized as follows: It has 30 0 and has the ability to make micro-convex lens, and can control different curvatures as needed. The method of ignoring the mold is complicated, and the single mirror 30 can control the microfabrication by controlling the microfabrication by the setting of the pressure difference, and the soil is controlled and quite stable. The second mussel's programmable control device or production mold is used as a mass production system to achieve the characteristics of life.

1283655 V. INSTRUCTIONS (6) Finally, the county lens array 5 i worthy of re-inclusion includes micro-forms formed by the following technologies: optical lenses. 3 • The micro-lens of the focus can be used for knowing. Production of precision mold assembly. To the early sputum, applied to the production side ^ for the endoscopes required for biomedical equipment 'providing a small lens, the luminous rate I can improve the organic diode (〇LED) and the inorganic diode (10) 6 Special::: The light source of the flat panel display backlight module is uniform and the degree is wide, and the 疋王彩面板' includes PDA (single machine, car screen and mobile instrument panel, etc.) As described above, the present invention has excellent advancement and practicability in the same kind of products, and at the same time, the technical knowledge of such structures is frequently investigated at home and abroad, and the same structure is not found in the literature. New patent requirements, 提出 apply in accordance with the law. ^ ^ Quasi, the above is only one of the preferred embodiments of the present invention, so the equivalent of the application of the present invention and the scope of the patent application It is intended to be included in the scope of the patent of the present invention. Page 10 1283655 Brief description of the drawing [Simple description of the drawing] The first figure is a schematic diagram of the structural change produced when the film structure is subjected to a uniform pressure difference. The second figure is the deflection of the present invention. Mold The third drawing is a schematic view of the forming of the micro concave lens of the present invention. The fourth drawing is a schematic view of the forming of the micro convex lens of the present invention. The fifth drawing is a comparison table of the results produced by the present invention under different pressure differences. Description] a film structure

10 photoresist mold 11 矽 wafer substrate 12 photoresist structure layer 2 0 PDMS polymer 3 0 flexible mold 3 1 depressed groove 3 2 thin film structure layer 3 3 inner cavity 4 0 glass substrate 5 0 curable polymer structure layer 5 0 'curable polymer structural layer

5 1 Microlens array 6 0 Environmental chamber 61 Transparent cover 7 0 Air pressure pump 80 UV light source

Page 11

Claims (1)

丄283655 The method for manufacturing a microlens array by using a pull-type chess piece is formed by using an elastomer material to form an array of a flexible film structure layer; b. bonding the flexible mold to a substrate, forming an array between the enamel film structure layer and the substrate There is a 5 cavity; / 'the flexible mold is shaped to flex the predetermined cavity pressure of the mold, c, in the flexible mold of the flexible material to form a curable force regulating environment cavity, The microlens array can be obtained by predetermining the pressure difference and deforming the shape of the flexible mold mirror, and at the same time making it possible to obtain a high score after forming. 2. According to the method of applying for a patent range of microlens arrays, among which materials. The film structure layer is coated with a curable sorghum molecular structure layer and placed in an array of flexible film structure layers formed between the environment cavity and the cavity of the mold to form a micro-transparent cured polymer structure layer. Forming; substructure layer is solidified, and demolded to remove the application of the flexible mold described in item 1 to produce the elastomer material using PDMS polymer 3. A method of fabricating a microlens array using a flexural mold according to the first aspect of the patent application, wherein the flexural mold is demolded by a preformed photoresist mold. 4. A method for fabricating a microlens array using a flexural mold according to the third aspect of the patent application, wherein the photoresist mold is formed by using a yellow light lithography technique on a substrate to form a photoresist layer having a predetermined height and a cylindrical shape. Formed, and the flexible mold is coated with a PDMS polymer at a predetermined speed on the photoresist mold Page 12 1283655 VI. Apply for the patented range of photoresist layer, and demolish it after curing at the appropriate time and temperature, and make the application of the flexible mold as described in item 1 of the patent application scope. The method of the invention wherein the polymer-cured material is UV-cured to be irradiated by an ultraviolet light source to produce a curing agent. 6. A method of manufacturing a microlens array using a flexural mold according to claim 1 of the patent application scope, wherein the environment The cavity seal has a transparent cover, and an air pressure pump is further connected therein to control the pressure of the environment cavity. 7. The method for manufacturing the microlens array by using the flex mold according to the first claim of the patent application scope The pressure difference in the formation of the polymer structural layer ranges from 10 kPa.