JP2006003519A - Method for manufacturing optical component and method for manufacturing micro-lens array - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an optical component (microlens array) capable of conveniently manufacturing an optical component at a low cost. <P>SOLUTION: The method for manufacturing a micro-lens array comprises the following processes: a negative-type photoreceptive material layer 202 is formed on a first substrate 200 and the photoreceptive material layer 202 is exposed; and second substrate 102 is fixed on the surface of the opposite side to the surface in contact with the first substrate 200 of the photoreceptive material layer 202, the first substrate 200 is removed after fixation, the photoreceptive material layer 202 is developed and, thereby, an external shape of the desired optical performance is formed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical component manufacturing method and a microlens array manufacturing method.

  In a conventional microlens manufacturing method, a Ni electroformed master is pressed onto a UV (ultraviolet ray) resin layer previously formed on the surface of a glass substrate to transfer the microlens surface, and then UV is applied from the back side of the glass substrate. After irradiating light and curing the UV resin to form irregularities on the microlens surface, the microlens surface is formed by filling and curing the UV resin layer after the irregularity formation with an optical resin having a predetermined refractive index. There is a 2P (Photo-Polymer) method (see, for example, Patent Document 1).

  In another conventional microlens manufacturing method, a metal thin film made of Al, Ti, Ni, Cr or the like is formed on the surface of a glass substrate by a well-known thin film forming technique such as a sputtering method, and then a pixel of a liquid crystal display panel The glass substrate is formed in a solution containing ions having a higher refractive index than the ions contained inside the glass substrate by forming a small aperture window corresponding to the arrangement in a metal thin film by a well-known photolithography technique. There is an ion exchange method for forming a substantially hemispherical refractive index distribution type microlens in which the refractive index gradually decreases from the vicinity of the metal mask opening window toward the periphery by being immersed for a predetermined time (for example, Patent Document 2). reference).

JP 2004-12941 A (FIG. 2, [0019] to [0021]) Japanese Patent No. 2641774 (FIG. 4)

  In the technique described in the conventional patent document 1, it is necessary to use a Ni electroformed master having approximately the same size as the glass substrate. When attempting to increase the size of the glass substrate, the flatness cannot be maintained. There is a limit to the size of the electroformed master that can be manufactured, making it difficult to handle large-area glass substrates. In addition, bubbles are likely to enter during the process of transferring the microlens surface by pressing the Ni electroformed master on the UV resin layer on the glass substrate, leading to a reduction in quality such as a manufacturing error in refractive index. Moreover, since it is necessary to carry out by forming UV resin on a glass substrate, it was expensive.

  Further, in the technique described in the conventional patent document 2, since the ion permeation is performed through the minute opening window formed in the metal thin film, the microlens shape is limited to a substantially hemispherical shape, and the microlens shape has a degree of freedom. Absent. In addition, the process from the formation of the metal thin film on the glass substrate to the ion exchange through the formation of the minute aperture window is complicated and the manufacturing cost is high.

  The present invention has been made to solve such problems, and provides an optical component manufacturing method and a microlens array manufacturing method capable of manufacturing a large-area optical component easily and at low cost. Objective.

  The method of manufacturing an optical component according to the present invention includes a step of forming a negative photosensitive material layer on a first substrate, a step of exposing the photosensitive material layer, and the first of the photosensitive material layer. Fixing the second substrate to a surface opposite to the surface in contact with the substrate, removing the first substrate after fixing the second substrate, and developing the photosensitive material layer And forming an outer shape having a desired optical performance. By such a method, an optical component can be easily manufactured at low cost.

  According to another aspect of the invention, there is provided a method for manufacturing an optical component, comprising: forming a positive photosensitive material layer on a first substrate having lightness; and passing the photosensitive material layer through the first substrate. Exposing the photosensitive material layer to a surface of the photosensitive material layer opposite to the surface in contact with the first substrate; and fixing the second substrate after fixing the second substrate. Removing the substrate, and developing the photosensitive material layer to form an outer shape having a desired optical performance. By such a method, an optical component can be easily manufactured at low cost.

  In the step of exposing the photosensitive material layer, the photosensitive material layer may be exposed using a photomask or a laser. Thereby, it is possible to form an optical component suitable for the application and function.

  In addition, the microlens array manufacturing method according to the present invention is used with a display panel that realizes screen display with a plurality of pixels, and includes a plurality of microlenses provided corresponding to one or more of the pixels. A method for manufacturing an array, comprising: forming a negative photosensitive material layer on a fixed substrate; exposing the photosensitive material layer so that a portion constituting a microlens is cured; and the photosensitive material Fixing the display panel substrate to a surface of the layer opposite to the surface in contact with the fixed substrate; removing the substrate after fixing the display panel substrate; developing the photosensitive material layer; And a step of forming a microlens array by removing portions other than the hardened portion. By such a method, the microlens array can be easily manufactured at low cost.

  Another microlens array manufacturing method according to the present invention is used with a display panel that realizes screen display with a plurality of pixels, and includes a plurality of microlenses provided corresponding to one or more of the pixels. A method of manufacturing a microlens array, comprising: forming a positive photosensitive material layer on a transparent fixed substrate; and passing through the fixed substrate so that a portion other than a portion constituting the microlens is decomposed. Exposing the photosensitive material layer, fixing the display panel substrate to a surface of the photosensitive material layer opposite to the surface in contact with the fixed substrate, and after fixing the display panel substrate A step of removing the substrate, and a step of developing the photosensitive material layer and forming a microlens array by removing the decomposed portion A. By such a method, the microlens array can be easily manufactured at low cost.

  In the step of exposing the photosensitive material layer, the photosensitive material layer may be exposed using a photomask or a laser. Thereby, it is possible to form a microlens array that matches the application and function.

  Further, the method may further include a step of cutting the formed microlens array for each predetermined region, and the photosensitive material layer is not formed in the cutting region.

  The display panel may be a liquid crystal display panel.

  According to the method for manufacturing an optical component and the method for manufacturing a microlens array according to the present invention, an optical component and a microlens array can be manufactured easily and at low cost.

Embodiment 1 of the Invention
Embodiment 1 of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view of a liquid crystal display device.

  In FIG. 1, a liquid crystal display device 100 is configured by sandwiching a liquid crystal 103 between two transparent substrates 101 and 102 which are liquid crystal display panels that realize screen display with a plurality of pixels. The transparent substrates 101 and 102 are made of, for example, glass, polycarbonate, acrylic resin, or the like. A color filter layer 104 is formed on the surface in contact with the liquid crystal 103 which is the back surface side of the first transparent substrate 101 disposed on the front surface side of the liquid crystal display device 100. The color filter layer 104 is composed of, for example, three regions that perform red (R), green (G), and blue (B) color display. The black matrix 105 is a light shielding film disposed between the pixels of the color filter layer 104, and prevents light leakage between the pixels.

A transparent electrode 106 and an alignment film 107 are sequentially stacked on the back surface of the color filter layer 104. The transparent electrode 106 is formed of, for example, a transparent conductive thin film (ITO: Indium Tin Oxide) by photolithography. The alignment film 107 is formed of, for example, an organic thin film such as a polyimide thin film that is a polymer material, and plays a role of aligning the molecules of the liquid crystal 103 in a predetermined direction. A TFT element 108 is formed on the surface in contact with the liquid crystal 103 on the front surface side of the second transparent substrate 102 disposed on the back surface side of the liquid crystal display device 100, and the transparent electrode is further formed in the same manner as the first substrate 101 described above. 106 and an alignment film 107 are stacked. The TFT element 108 is a switching element for driving a liquid crystal.

On the back side of the second transparent substrate 102, a microlens array 109 and a rim 110 as optical components are provided.

FIG. 2 is a plan view showing the positional relationship between the transparent substrate, the microlens array, and the rim.

1 and 2, the microlens array 109 is provided so as to be surrounded by a rim 110 provided on the outer peripheral edge on the back surface side of the transparent substrate 102. Here, the microlens array 109 includes a plurality of microlenses having a diameter of about 10 × 10 ⁻⁶ m, for example, in order to improve light utilization efficiency. The microlens array 109 is a display panel that realizes screen display with a plurality of pixels. A plurality of microlenses 109 a that are used together with the transparent substrate 102 and are provided corresponding to one or a plurality of pixels are provided. A pixel is a small unit that stores color / brightness information by subdividing the entire LCD panel screen into a grid pattern. The amount of information (bit: bits) stored for each pixel can express colors including light and dark. Is decided. The micro lens 109a generally refers to a minute lens having a diameter of several millimeters or less. The rim 110 is formed at a height equal to or higher than the apex of the convex portion of the microlens array 109 without being interrupted along the outer peripheral edge on the back surface side of the second transparent substrate 102. A polarizing plate 111 (described later) attached to the back surface side of the transparent substrate 102 is provided for the purpose of maintaining flatness. The rim 110 is preferably made of the same material as the microlens array 109. The polarizing plate 111 is an optical member having a function of transmitting only a specific polarization component with respect to incident light, and is attached to both outer surfaces of the two transparent substrates 101 and 102.
The spacers 112 are resin particles that control the height (cell gap) of the liquid crystal layer 103 between the transparent substrates 101 and 102, and a plurality of spacers 112 are scattered over the entire range between the transparent substrates 101 and 102.

A large number of transparent substrates 101 and 102 are taken by a large mother substrate.

FIG. 3 is a plan view of a mother substrate which is a transparent substrate. On the mother substrate 1000, the transparent substrates 101 or 102 are arranged at regular intervals. In each region of the plurality of first substrates 101, a color filter layer 104, a transparent electrode 106, and an alignment film 107 are laminated on the back side. In each region of the plurality of second transparent substrates 102, a microlens array 109 and a rim 110 are formed on the back surface side, and a TFT element 108, a transparent electrode 106, and an alignment film 107 are stacked on the front surface side. . Each transparent substrate 101 or 102 is formed so as to be separable from the mother substrate 1000. In particular, as will be described later, the negative-type thick-walled ultraviolet curable photoresist 202 as a photosensitive material layer that forms the basis of the microlens array 109 is not formed in the cut region.

Next, the manufacturing method of the microlens array concerning this invention is demonstrated using figures.

FIG. 4 is a diagram showing a method for manufacturing a microlens array according to the present invention.

First, as shown in FIG. 4A, a negative type thick-curing UV curable photoresist 202, which is a negative type photosensitive material layer, is formed on a fixed substrate 200 as a first substrate. That is, a Teflon (registered trademark) film 201 as a release material having a thickness of about 10 × 10 ⁻⁹ m formed by plasma CVD (Chemical Vapor Deposition) on the surface of a fixed substrate 200 formed of transparent glass or an aramid film. Then, a negative type thick UV curable photoresist 202 is applied to the thickness of about 30 × 10 ⁻⁶ m by spin coating to form a negative type photosensitive material layer. Thereafter, baking is performed for 30 minutes in an environment of about 100 ° C.

The negative-type thick-walled ultraviolet curable photoresist 202 may be any transparent material such as a photosensitive sol-gel resin that has ultraviolet curing. Further, fluorine, metal fine particles, complexes, and the like may be contained in the exemplified photosensitive sol-gel resin.

The fixed substrate 200 is most preferably formed of transparent glass with little thermal contraction or thermal expansion. On the other hand, even if it is an aramid film, when the baking temperature is set to 200 ° C., for example, the thermal shrinkage rate is almost 0% as in the case of transparent glass, and it is suitable as a material without impairing the lens shape. Moreover, since this aramid film has a very large elastic modulus of 1500 × 9.8 × 10 ⁴ N / m ² , the second transparent substrate 102 as a second substrate and a liquid crystal display panel substrate to be described later is used. The work efficiency of bonding is also good.

In addition to the above examples, PET (Polyethylene-terephthalate) or a metal plate may be used, and it is not necessary to be transparent. However, since the fixed substrate 200 is thermally contracted or thermally expanded at the time of baking, it is more preferable to use the fixed substrate 200 made of transparent glass or an aramid film as described above.

Next, as shown in FIG. 4B, a negative-type thick UV-curable photoresist as a negative-type photosensitive material layer so that a portion 202a constituting the microlens 109 as an optical component is cured. 202 is exposed. That is, the photomask 203 is arranged on the surface of the negative-type thick UV curable photoresist 202 after the baking process, and is about 200 × 10 ⁷ toward the surface of the negative thick-type UV curable photoresist 202. Exposure is performed with an output of J / m ² .

Here, the photomask 203 has a lens pattern formed in gray scale gradation, and each lens pattern is provided corresponding to one or a plurality of pixels of the liquid crystal display panel. Each lens shape is a hexagon, and the maximum diameter of the opposite apex distances of the hexagon has a lens diameter of about 110 × 10 ⁻⁶ m. Further, the transmittance at the center of the lens is set to 100%, and the transmittance is reduced concentrically toward the outer periphery of the lens in accordance with the curvature having a radius of about 88 × 10 ⁻⁶ m, and the transmittance is 0 at the maximum diameter portion. % Is adjusted in advance so as to be%. Therefore, as shown in FIG. 4B, a plurality of convex cured portions 202a having a certain curvature are formed by curing in correspondence with one or more pixels of the liquid crystal display panel. On the other hand, the uncured portion 202b that is the remaining portion remains uncured. Here, the transmittance control of the photomask 203 was performed by coating a silver chloride emulsion on a glass substrate and directly drawing while applying power modulation with a laser. In addition to this method, the transmittance may be controlled by controlling the pixel dot pattern density. In this case, the dot pattern is an ink jet method, or after forming a Cr light-shielding film on a glass substrate, a resist is applied, the resist is exposed to dots with a laser, the resist is further developed, and the Cr light-shielding film The minute holes may be formed by etching. Alternatively, the minute holes may be formed by directly laser processing a light shielding film such as Cr into dots.

It should be noted that between the surface of the negative-type thick UV curable photoresist 202 and the photomask 203, the dirt of the photomask 202 is prevented from adhering to the surface of the negative thick-type UV curable photoresist 202. A gap of 10 × 10 ⁻⁶ m or less is provided.

Next, as shown in FIG. 4C, a baking process is applied to the negative-type, thick-walled ultraviolet curable photoresist 202 and the fixed substrate 200 after exposure.

Next, as shown in FIG. 4D, a surface 202A of the negative thick UV curable photoresist 202 as a negative photosensitive material layer that is in contact with the fixed substrate 200 as the first substrate; The second transparent substrate 102 as a second substrate and a liquid crystal display panel substrate is formed on the opposite surface 202B by using a thermosetting adhesive 204, and a negative type thick-walled UV curable photoresist 202. Paste to and fix. The thermosetting adhesive 204 is more preferably an epoxy type. Here, the second transparent substrate 102 is a glass substrate having a thickness of about 250 × 10 ⁻⁶ m. The bonding was performed using as an index an alignment mark (alignment mark) formed in advance on the surface of the negative-type thick-walled ultraviolet curable photoresist 202 by exposure. Note that any or all of the transparent electrode 106, the alignment film 107, and the TFT element 108 may be formed in advance on the transparent substrate 102 at this stage.

Next, as shown in FIG. 4E, after fixing the second substrate, the transparent substrate 102 as the liquid crystal display panel substrate, the fixed substrate 200 as the first substrate is removed. That is, the second transparent substrate 102 and the negative type thick UV curable photoresist 202 are bonded using the thermosetting adhesive 204, and then cured and bonded in an environment of about 80 ° C. for about 30 minutes. Thereafter, the fixed substrate 200 is removed by peeling.

Next, as shown in FIG. 4 (f), after removing the fixed substrate 200 as the first substrate, the negative thick UV curable photoresist 202 as the photosensitive material layer is developed and cured. The uncured portion 202b other than the portion 202a is removed. Then, the microlens array 109 is formed on the back surface side of the transparent substrate 102. That is, the second transparent substrate 102 as the substrate for the liquid crystal display panel, and the negative type thick-walled ultraviolet curable photoresist 202 having the cured portion 202a and the uncured portion 202b are, for example, 2%. This was developed using an aqueous solution of TMAH (Tetramethyl Ammonium Hydroxide: Tetramethylammonium hydroxide), and the uncured portion 202b was dissolved and removed to form the microlens array 109 with the cured portion 202b composed of a plurality of convex portions. According to the experimental values, the microlens 109a has a refractive index of 1.52, and the microlens array 109 having extremely high luminance characteristics can be formed.
Further, as shown in FIG. 3, when the microlens array 109 is formed on the mother substrate 1000 on which a plurality of transparent substrates 102 are arranged, the formed microlens array 109 is further provided in a predetermined region. Cut every time. At this time, the negative thick UV curable photoresist 202 as the photosensitive material layer is formed in a region other than the cutting region, so that the microlens array 109 is cut. There is no.

  By such a method, a large-area microlens array can be easily manufactured at low cost. In particular, in the present invention, since there is no need to interpose a substrate or the like between the photomask 203 and the negative type thick-curing UV curable photoresist 202, the distance between the two can be shortened, so the negative can be accurately performed. The mold thick UV curable photoresist 202 can be cured.

  Next, another example of the method for manufacturing the microlens array according to the first embodiment of the invention will be described.

  FIG. 5 is a perspective view for explaining a part of the manufacturing process in another example of the method for manufacturing the microlens array according to the first embodiment of the invention.

  In the step of exposing the negative thick UV curable photoresist 202 as the photosensitive material layer described with reference to FIG. 4B, the negative thick UV curable photoresist 202 using the photomask 203 is used. However, it is also possible to expose the negative-type thick UV curable photoresist 202 with a laser instead of the photomask 203 using a laser.

  In FIG. 5, if the exposure amount is changed by changing the output of the laser light emitted from the laser apparatus 2000, the lens shape is not limited to the spherical shape, but for example, an aspherical shape, a Fresnel type lens, A microlens array 109 can be formed in accordance with the function.

Embodiment 2 of the Invention
A second embodiment of the present invention will be described with reference to the drawings.

  FIG. 6 is a diagram showing a method for manufacturing a microlens array according to the present invention.

4 is different from the manufacturing method shown in FIG. 4 in that a photomask 203 is formed on a negative-type thick-curing UV-curable photoresist 202 which is a negative-type photosensitive material layer in the manufacturing method shown in FIG. In contrast, the microlens array 109 is formed by exposing to the positive type, and in the manufacturing method shown in FIG. In contrast, the microlens array 109 is formed by exposure through the photomask 203.

First, as shown in FIG. 6A, a positive-type thick-walled UV-curable photoresist 302, which is a positive-type photosensitive material layer, is formed on a fixed substrate 200a as a first substrate having transparency. To do. That is, a positive-type thick UV curable photoresist 302 having a thickness of about 30 μm is formed on the surface of the fixed substrate 200 formed of transparent glass or aramid film by a spin coating method through a Teflon film 201 as a release material. Then, a negative photosensitive material layer is formed. Thereafter, baking is performed for 30 minutes in an environment of about 100 ° C.

Next, as shown in FIG. 6B, a positive photosensitive material layer is formed through the fixed substrate 200a so that the portion 302b other than the portion 302a constituting the microlens 109 as the optical component is disassembled. The positive-type, thick-walled UV-curable photoresist 302 is exposed. That is, a photomask 203 is disposed on the back surface side of the fixed substrate 201 on which the positive-type thick-walled UV curable photoresist 302 after the baking process is formed, and the positive-type thick-walled UV-curable photoresist is provided. Exposure to 302 is performed at an output of about 200 mJ / cm ² .

Here, the photomask 203 has a lens pattern formed in gray scale gradation, and each lens pattern is provided corresponding to one or a plurality of pixels of the display panel. The individual lens shape is a hexagon, and the maximum diameter of the opposite apex distances of the hexagon has a lens diameter of about 110 × 10 ⁻⁶ m. Further, the transmittance at the center of the lens is set to 0%, and the transmittance is increased concentrically along the curvature of a radius of about 88 × 10 ⁻⁶ m toward the outer periphery of the lens, and the transmittance is 100 at the maximum diameter portion. % Is adjusted in advance so as to be%. Accordingly, as shown in FIG. 6B, a disassembled portion 302b is formed, and a plurality of convex non-decomposed portions 302a having a certain curvature are formed corresponding to one or a plurality of pixels of the display panel. The The decomposed portion 302b is removed by development in a later step (FIG. 6F).

The subsequent manufacturing steps are the same as those shown in FIGS.

By such a method, a large-area microlens array can be easily manufactured at low cost.

Embodiment 3 of the Invention
Embodiment 3 of the present invention will be described with reference to the drawings.

FIG. 7 is a view showing a cross section of the liquid crystal display device.

  In FIG. 7, the difference from FIG. 1 described in the first embodiment of the invention will be described. In FIG. 1, the microlens array 109 and the rim 110 are provided on the back side of the liquid crystal display device 100, but in FIG. It is provided on the surface side of the first transparent substrate 101 provided on the front side of the liquid crystal display device 100a.

  Even in such a configuration, if the manufacturing method shown in Embodiment 1 or 2 of the present invention is used, the microlens array 109 can be easily provided on the front surface side of the first transparent substrate 101 of the liquid crystal display device 100a. In addition, a liquid crystal display device that can be provided at low cost and has a wide viewing angle can be manufactured.

It is a figure which shows the cross section of a liquid crystal display device. It is a top view which shows the arrangement | positioning relationship of a transparent substrate, a micro lens array, and a rim | limb. It is a top view of the mother substrate of a transparent substrate. It is a figure which shows the manufacturing method of the micro lens array concerning this invention. It is a perspective view explaining a part of manufacturing process in the other Example of the manufacturing method of the micro lens array concerning Embodiment 1 of invention. It is a figure which shows the manufacturing method of the micro lens array concerning this invention. It is a figure which shows the cross section of a liquid crystal display device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Liquid crystal display device 101 1st transparent substrate 102 2nd transparent substrate 103 Liquid crystal 104 Color filter layer 105 Black matrix 106 Transparent electrode 107 Orientation film 108 TFT element 109 Microlens array 110 Rim 111 Polarizing plate 200 Fixed substrate 201 Teflon film 202 Negative thick UV curable photoresist 203 Photomask 204 Thermosetting adhesive 302 Positive thick UV curable photoresist 1000 Mother substrate 2000 Laser device

Claims (8)

Forming a negative photosensitive material layer on a first substrate;
Exposing the photosensitive material layer;
Fixing a second substrate to a surface of the photosensitive material layer opposite to a surface in contact with the first substrate;
Removing the first substrate after securing the second substrate;
Forming the outer shape of the desired optical performance by developing the photosensitive material layer. Forming a positive photosensitive material layer on a first substrate having transparency;
Exposing the photosensitive material layer through the first substrate;
Fixing a second substrate to a surface of the photosensitive material layer opposite to a surface in contact with the first substrate;
Removing the first substrate after securing the second substrate;
Forming the outer shape of the desired optical performance by developing the photosensitive material layer.   3. The method of manufacturing an optical component according to claim 1, wherein in the step of exposing the photosensitive material layer, the photosensitive material layer is exposed using a photomask or a laser. A method of manufacturing a microlens array that is used together with a display panel that realizes screen display with a plurality of pixels, and includes a plurality of microlenses provided corresponding to one or more of the pixels,
Forming a negative photosensitive material layer on a fixed substrate;
Exposing the photosensitive material layer so that a portion constituting the microlens is cured;
Fixing a display panel substrate to a surface of the photosensitive material layer opposite to a surface in contact with the fixed substrate;
Removing the substrate after fixing the display panel substrate;
And developing the photosensitive material layer to form a microlens array by removing portions other than the cured portion. A method of manufacturing a microlens array that is used together with a display panel that realizes screen display with a plurality of pixels, and includes a plurality of microlenses provided corresponding to one or more of the pixels,
Forming a positive photosensitive material layer on a fixed substrate having transparency;
Exposing the photosensitive material layer through the fixed substrate so that a portion other than a portion constituting the microlens is decomposed; and
Fixing a display panel substrate to a surface of the photosensitive material layer opposite to a surface in contact with the fixed substrate;
Removing the substrate after fixing the display panel substrate;
And developing the photosensitive material layer and removing the decomposed portion to form a microlens array.   6. The method of manufacturing a microlens array according to claim 4, wherein in the step of exposing the photosensitive material layer, the photosensitive material layer is exposed using a photomask or a laser. Furthermore, it comprises a step of cutting the formed microlens array for each predetermined region,
6. The method of manufacturing a microlens array according to claim 4, wherein the photosensitive material layer is not formed in the cut region. 6. The method of manufacturing a microlens array according to claim 4, wherein the display panel is a liquid crystal display panel.

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