JP2007183363A - Mother substrate, method for manufacturing the mother substrate, and method for manufacturing the microlens array substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mother substrate capable of suppressing warpage of a glass substrate and cracking of microlens arrays, caused by the difference in the coefficient of thermal expansion between the glass substrate and the microlens arrays. <P>SOLUTION: The mother substrate 1000 is for cutting out a large number of microlens array substrates 500, having a plurality of microlenses 200a, and comprises a glass substrate (second transparent substrate) 102 and, formed thereon, a plurality of microlens arrays 200, each having a plurality of microlenses made mainly of glass. Among the plurality of microlens arrays 200, the adjacent microlens arrays 200 are arranged apart from each other. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a mother substrate, a method for manufacturing the mother substrate, and a method for manufacturing a microlens array substrate. More particularly, the present invention relates to a mother substrate for taking a plurality of microlens array substrates having a plurality of microlenses, and a method for manufacturing the mother substrate. The present invention also relates to a method for manufacturing a microlens array substrate, in which a microlens array substrate having a plurality of microlenses is multi-faced from a mother substrate.

  In a liquid crystal display device, a technique using a microlens array has been proposed to achieve high brightness and high viewing angle. According to this technology, by forming a microlens array on the back side of a transparent substrate, backlight light can be condensed so as to avoid TFT elements and black matrix formed on the transparent substrate. It is possible to increase efficiency and achieve high brightness.

Patent Document 1 discloses a method of forming a microlens array made of glass on a glass substrate. In the method described in Patent Document 1, a microlens array is formed by forming a film of a photosensitive glass paste made of glass powder and a photosensitive resin on a substrate, and performing exposure, development, and heat treatment.
JP-A-8-166502

  When a microlens array is formed on a transparent substrate by the manufacturing method described in Patent Document 1, it has been found that various problems occur based on the difference in thermal expansion coefficient between the transparent substrate and the microlens array. . FIG. 7 is a partial cross-sectional view of a microlens array substrate in which a microlens array is formed on a transparent substrate. A microlens array 2 having a plurality of glass microlenses 21 is formed on a glass transparent substrate 1. In this example, adjacent microlenses 21 are coupled by a coupling unit 22.

The microlens array 2 is formed on the transparent substrate 1 by sensitizing and developing a photosensitive glass paste containing glass powder, and then baking the photosensitive glass paste. However, the microlens array 2 is heated between the glass powder and the transparent substrate 1. If there is a difference in expansion coefficient, stress remains between the fired microlens array 2 and the transparent substrate 1, and residual strain occurs. In the experiment, a material of 70 × 10 ⁻⁷ (/ ° C.) was used for the glass powder, and a material of 38 × 10 ⁻⁷ (/ ° C.) was used for the transparent substrate 1. Due to the residual stress / residual strain generated by this difference in thermal expansion coefficient, a problem arises in that the microlens array substrate has a curved warp such that the transparent substrate 1 side is convex and the microlens array 2 side is concave.

  Such a problem becomes prominent particularly when a multi-sided microlens array substrate is formed using a mother substrate. In other words, when a microlens array substrate is multi-faceted using a mother substrate, a plurality of microlenses are formed on the entire surface of the mother substrate without gaps to form a large-area microlens array. The warp of the mother substrate based on the residual stress / residual strain caused by the difference in the coefficient also increases, and the warp of a plurality of microlens array substrates that are multi-faced from the mother substrate also increases.

Such warpage of the microlens array substrate adversely affects the light transmitted through the microlens. In particular, the microlens array substrate is used in a liquid crystal display device. However, the use of a warped microlens array substrate in the liquid crystal display device causes a problem of deteriorating the display quality of the liquid crystal display device.
Furthermore, cracks may occur in the microlens array 2 between the microlenses 21 due to residual stress and residual strain generated due to the difference in thermal expansion coefficient. Not only that, the surface of the transparent substrate 1 made of glass sometimes peeled off. In particular, when a transparent substrate made of hard glass was used, peeling of the surface was remarkable.

  The present invention has been made to solve such problems, a mother substrate that can suppress the occurrence of warpage of the glass substrate and cracks of the microlens array caused by the difference in thermal expansion coefficient between the glass substrate and the microlens array, It is an object of the present invention to provide a method for manufacturing this mother substrate and a method for manufacturing a microlens array substrate.

  A mother substrate according to the present invention is a mother substrate for multi-sided microlens array substrate having a plurality of microlenses, and is formed on a glass substrate and a plurality of micros composed mainly of glass. And a plurality of microlens arrays each having a lens. Among the plurality of microlens arrays, adjacent microlens arrays are spaced apart from each other. By comprising in this way, generation | occurrence | production of the curvature of the glass substrate and the crack of a microlens array which are produced by the difference of the thermal expansion coefficient of a glass substrate and a microlens array can be suppressed.

  In addition, it comprises a plurality of outer frame portions formed in a frame shape on the glass substrate along the outer peripheral edge of each of the plurality of micro lens arrays, and the adjacent outer frame portions of the plurality of outer frame portions are These are arranged apart from each other. Here, the plurality of outer frame portions may be formed of the same material as the plurality of microlens arrays. Adjacent microlenses are coupled by a glass material. The plurality of microlens arrays may be arranged in a matrix.

  A method for manufacturing a mother substrate according to the present invention is a method for manufacturing a mother substrate for taking a plurality of microlens array substrates having a plurality of microlenses, wherein a plurality of microlenses mainly composed of glass are formed on a glass substrate. A step of forming a plurality of microlens arrays each having a lens, wherein in the step of forming a plurality of microlens arrays, of the plurality of microlens arrays, adjacent microlens arrays are spaced apart from each other. To do. By using such a manufacturing method, it is possible to suppress the warpage of the glass substrate and the occurrence of cracks in the microlens array caused by the difference in thermal expansion coefficient between the glass substrate and the microlens array.

  In addition, the method further includes a step of projecting a plurality of outer frame portions in a frame shape on the glass substrate along the outer peripheral edge of each of the plurality of microlens arrays. Among the outer frame portions, adjacent outer frame portions are arranged apart from each other. Here, a plurality of microlens arrays and a plurality of outer frame portions may be formed simultaneously. In addition, the step of forming the plurality of microlens arrays includes a step of forming a lens forming layer including glass powder and forming a plurality of microlens shapes on a glass substrate, and firing the lens forming layer to be adjacent to each other. Forming a microlens coupled between the microlenses. The lens forming layer is formed by applying a photosensitive glass paste made of glass powder and a photosensitive resin on a glass substrate, and exposing and developing the coated glass paste through a gray scale mask. It is preferable to include a step of forming a microlens shape having a coupling portion.

A method of manufacturing a microlens array substrate according to the present invention is a method of manufacturing a microlens array substrate in which a microlens array substrate having a plurality of microlenses is multi-faced from a mother substrate. Forming a mother substrate by forming a plurality of microlens arrays each having a plurality of microlenses as components; and a step of cutting the mother substrate into a plurality of microlens array substrates. Then, among the plurality of microlens arrays, adjacent microlens arrays are arranged apart from each other, and in the step of cutting out the plurality of microlens array substrates, along the cutting line provided between the adjacent microlens arrays, Characterized by cutting the mother board A. By using such a manufacturing method, it is possible to suppress the warpage of the glass substrate and the occurrence of cracks in the microlens array caused by the difference in thermal expansion coefficient between the glass substrate and the microlens array.
Here, a step of polishing the outer peripheral end surface of the cut microlens array substrate may be further provided.

  ADVANTAGE OF THE INVENTION According to this invention, generation | occurrence | production of the curvature of a glass substrate and the crack of a microlens array which arises by the difference in the thermal expansion coefficient of a glass substrate and a microlens array can be suppressed.

Embodiment 1 of the Invention
A liquid crystal display device having a plurality of microlenses will be described with reference to the drawings. FIG. 1 is a cross-sectional view schematically showing a configuration of a liquid crystal display device having a plurality of microlenses.
As shown in FIG. 1, the liquid crystal display device includes a liquid crystal display panel 100, a microlens array 200 having a plurality of microlenses 200a, and a rim 201. As shown in FIG. 1, in the liquid crystal display panel 100, the inner surfaces of two transparent substrates 101 and 102 are arranged to face each other, and a liquid crystal layer 103 is sandwiched between the two transparent substrates 101 and 102. ing.

  As shown in FIG. 1, spacers 110 for controlling the height (cell gap) of the liquid crystal layer 103 are dispersed between the first and second transparent substrates 101 and 102. The first and second transparent substrates 101 and 102 are bonded together by a sealing material 111 applied along the outer peripheral edges of the first and second transparent substrates 101 and 102. On both outer surfaces of the liquid crystal display panel 100, polarizing plates 109 are respectively attached. The polarizing plate 109 on the front side of the liquid crystal display panel 100 is directly attached on the outer surface of the first transparent substrate 101, and the polarizing plate 109 on the back side of the liquid crystal display panel 100 is on the outer surface of the second transparent substrate 102. The rim 201 is attached to the rim 201.

  As shown in FIG. 1, the first transparent substrate 101 is formed of a rectangular thin plate, and the material of the first transparent substrate 101 is glass, polycarbonate, acrylic resin, or the like. Further, as shown in FIG. 1, a color filter layer 104, a transparent electrode 106, and an alignment film 107 are sequentially laminated on the inner surface of the first transparent substrate 101. A black matrix 105 as a light shielding film is formed between the pixels of the color filter layer 104.

  As shown in FIG. 1, the second transparent substrate 102 is formed of a rectangular thin plate, and glass is used as the material of the first transparent substrate 102. Further, as shown in FIG. 1, a TFT element 108, a transparent electrode 106, and an alignment film 107 are sequentially laminated on the inner surface of the second transparent substrate. For example, ITO (Indium Tin Oxide) is used as the material of the transparent electrode 106. As a material for the alignment film 107, for example, a polyimide thin film is used.

Here, if the second transparent substrate 102 contains an alkali metal oxide in glass, alkali ions diffuse into the semiconductor material formed during the heat treatment, leading to deterioration of film characteristics. It is preferable that no alkali metal oxide is contained. The second transparent substrate 102 desirably has chemical resistance that does not deteriorate due to various chemicals such as acid and alkali used in the photoetching process. Furthermore, it is desirable that the glass substrate has a high strain point, specifically, a strain point of 600 ° C. or higher so that the glass substrate does not shrink due to heat shrinkage in a liquid crystal manufacturing process such as film formation. Furthermore, it is preferable that the glass is excellent in meltability so as not to cause undesirable melting defects as a substrate in the glass. Although the thermal expansion coefficient of the 2nd transparent substrate 102 changes with kinds of glass material, it shall be 30 * 10 < ^-7 > (/ degreeC) or more and 50 * 10 < ^-7 > (/ degreeC) or less, for example.

  Further, as shown in FIG. 1, a microlens array 200 mainly composed of glass and a rim 201 are formed on the outer surface of the second transparent substrate 102. Here, the microlens array substrate 500 is constituted by the second transparent substrate 102, the microlens array 200, and the rim 201. As will be described later, the microlens array 200 and the rim 201 are formed by forming a photosensitive glass paste film made of glass powder (glass powder) and a photosensitive resin (resist) on the second transparent substrate 102, and exposing it. -It forms by baking after developing.

Next, the positional relationship between the microlens array 200 and the rim 201 of the microlens array substrate 500 will be described with reference to the drawings. FIG. 2 is a plan view when the microlens array substrate is viewed from the microlens array forming surface side.
As shown in FIG. 2, the microlens array 200 includes a plurality of microlenses 200a arranged in a staggered pattern. At this time, the adjacent microlenses 200a are coupled by the glass material on which the microlenses 200a are formed.

  The thickness δ (thickness after firing) from the upper surface of the transparent substrate 102 at the boundary between the microlenses 200a coupled with the glass material is preferably 0.1 μm ≦ δ ≦ 200 μm. A more preferable range is 0.5 μm ≦ δ ≦ 50 μm, and a more preferable range is 1 μm ≦ δ ≦ 10 μm. In the present embodiment, δ is 1.0 μm. When δ was larger than 200 μm, it was confirmed that cracking was caused by the stress of the glass film at the boundary during firing.

  Here, it is desirable that the expansion coefficients of the microlens array 200 and the second transparent substrate 102 are substantially the same. Specifically, when the expansion coefficient of the second transparent substrate 102 is α1 and the expansion coefficient of the microlens array 200 is α2, it is preferable that 0.3 × α1 <α2 <1.7 × α1. That is, it is desirable that the ratio of the difference between α1 and α2 with respect to α1 is 70% or less. By making the expansion coefficients of the two substantially the same, it is possible to prevent the microlens array 200 from being cracked and broken due to stress generated by the heat treatment.

Each micro lens 200a is formed to have a diameter of several millimeters or less, and is provided corresponding to the pixel of the display panel 100.
As shown in FIGS. 1 and 2, the rim 201 as an outer frame portion protrudes along the outer peripheral edge of the microlens array 200 and is formed in a frame shape. As shown in FIG. 1, the rim 201 is formed equal to or higher than the convex vertex of the microlens array 200. The rim 201 is provided for attaching the polarizing plate 109 to the second transparent substrate 102. The microlens array substrate 500 is multi-faced by a large mother substrate 1000 shown in FIG.

A mother substrate 1000 for multi-sided microlens array substrate 500 will be described with reference to the drawings. FIG. 3 is a plan view of the mother substrate as viewed from the side on which the microlens array is formed. 4 is a cross-sectional view taken along the line AA in FIG.
As shown in FIG. 3 and FIG. 4, a plurality of microlens arrays 200 and rims 201 surrounding the outer periphery thereof are arranged in a matrix at regular intervals on the mother substrate 1000. That is, as shown in FIG. 3 and FIG. 4, among the plurality of microlens arrays 200, adjacent microlens arrays 200 are arranged apart from each other. Of the plurality of rims 201, adjacent rims 201 are spaced apart from each other.

  Further, as shown in FIG. 3, cutting lines X1-X1, X2-X2,..., Xn-Xn, Y1-Y1, Y2-Y2, Y3- Y3 is set, and by cutting the mother substrate 1000 along these cutting lines X1-X1, etc., the microlens array substrate 500 can be multi-faced from the mother substrate 1000. In addition, as shown in FIG. 4, each cutting line X1-X1 and the like is set in a gap between adjacent rims 201. The interval between the outer walls of the adjacent rims 201 is set so that the rim 201 is not scraped even if the outer peripheral end face or corner of the microlens array substrate 500 after cutting is polished to prevent cullet generation, for example. Has been.

Next, a method for manufacturing the mother substrate and the microlens array substrate according to the first embodiment of the present invention will be described. FIG. 5 is a diagram showing a method for manufacturing the microlens array substrate according to the first embodiment of the present invention. 5 schematically shows a cross section of the mother substrate 1000 shown in FIG. 3 in the region where the microlens array 200 is formed.
First, as shown in FIG. 5A, a glass transparent substrate 102 was prepared. For example, a glass substrate having a thickness of 400 μm to 500 μm was used as the transparent substrate 102. Next, as shown in FIG. 5B, a lens forming layer 20 was formed by applying a photosensitive glass paste and forming a film over the entire area of one side of the transparent substrate 102. In the example shown in FIG. 5, a so-called negative photoresist in which the photosensitive portion is cured is used for the photosensitive resin in the photosensitive glass paste. Application methods include spin coating and slit coating.

  Here, the photosensitive glass paste contains glass powder (glass powder) and a photosensitive resin (resist) as main components. In order to prepare a photosensitive glass paste, first, a glass block is pulverized and made into fine particles of 10 μm or less. Thereafter, silane treatment is performed, the glass powder and the photosensitive resin are kneaded, and the glass powder is dispersed in the photosensitive resin. Thereby, a photosensitive glass paste can be prepared.

  The photosensitive resin is preferably an ultraviolet curable resin. It is preferable that the photosensitive resin can be developed with an organic solvent, an alkaline solution, or water. The ultraviolet curable resin preferably contains at least an acrylic copolymer having a carboxyl group and an ethylenically unsaturated group in the side chain and a photoreactive compound. An acrylic copolymer having a carboxyl group and an ethylenically unsaturated group in the side chain is a polymer binder component, and an acrylic copolymer formed by copolymerizing an unsaturated carboxylic acid and an ethylenically unsaturated compound is ethylene. It can be produced by adding an unsaturated group to the side chain.

  Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, and acid anhydrides thereof. Examples of the ethylenically unsaturated compound include methyl acrylate, methyl methacrylate, and ethyl acrylate. Examples of side chain ethylenically unsaturated groups include vinyl, allyl, and acrylic groups.

  Examples of the ethylenically unsaturated compound having a glycidyl group include glycidyl acrylate, glycidyl methacrylate, and allyl glycidyl ether. In the photosensitive resin contained in the photosensitive glass paste, a photosensitive polymer or a non-photosensitive polymer other than the above acrylic copolymer may be used in combination as a polymer binder component.

  Photopolymers include photo-insolubilized types and photo-solubilized types. As photo-insolubilized types, suitable polymers containing functional monomers or oligomers having one or more unsaturated groups per molecule are used. It is obtained by mixing photosensitive compounds such as aromatic diazo compounds, aromatic azide compounds, and organic halogen compounds with appropriate polymer binders, or by pendating photosensitive groups on existing polymers. Examples include photosensitive polymers or modified polymers thereof, and so-called diazo resins such as condensates of diazo amines and formaldehyde. In addition, as a light solubilizing type, a complex of an inorganic salt of a diazo compound or an organic acid, a mixture of a quinonediazide or the like with an appropriate polymer binder, a quinonediazo combined with an appropriate polymer binder, such as phenol or novolak Examples thereof include naphthoquinone-1,2-diazide-5-sulfonic acid ester of resin.

  Examples of the non-photosensitive polymer include polyvinyl alcohol, polyvinyl butyral, methacrylic acid ester polymer, acrylic acid ester polymer, acrylic acid ester-methacrylic acid ester copolymer, and α-methylstyrene polymer.

  As the photoreactive compound, a monomer or oligomer containing a carbon-carbon unsaturated bond having a known photoreactivity can be used. For example, photoreactive compounds include allyl acrylate, benzyl acrylate, butoxyethyl acrylate, butoxytriethylene glycol acrylate, and the like. Typical examples of oligomers include polyester acrylate, urethane acrylate, and epoxy acrylate.

  Examples of the photopolymerization initiator used for the ultraviolet curable resin include benzophenone, methyl o-benzoylbenzoate, 4,4-bis (dimethylamine) benzophenone, 4,4-bis (diethylamino) benzophenone, 4,4. -Combinations of reducing agents such as dichlorobenzophenone.

  Next, as shown in FIG. 5C, a gray scale mask 30 is arranged on the opposite side of the surface on which the lens forming layer 20 is formed, and the inside of the formation region of the microlens array 200 shown in FIG. Exposure. Here, the formation regions of the adjacent microlens arrays 200 are set apart from each other as shown in FIG. In the formation region of the microlens array 200, the exposure light irradiated from the grayscale mask 30 side is intensity-modulated by the lens formation region of the grayscale mask 30.

  More specifically, intensity modulation is applied so that the exposure intensity decreases concentrically with the central portion of the lens forming area as a maximum. The lens forming layer 20 is cured into a lens shape by the exposure light intensity-modulated by the lens forming region of the gray scale mask 30. At this time, the gray scale mask 30 is manufactured so that the rim 201 shown in FIG. 3 can be formed simultaneously with the microlens 200a. Then, by using the gray scale mask 30, the rim 201 forming region shown in FIG. 3 is also exposed to be cured into a rim shape. As described above, the microlens array 200 and the rim 201 can be efficiently formed on the transparent substrate 102 by simultaneously forming the plurality of microlenses 200 a and the rim 201 using the same gray scale mask 30.

Next, as illustrated in FIG. 5D, after the exposure of the lens forming layer 20 is completed, the uncured portion is removed by developing the lens forming layer 20. At this time, since the exposure and development processes are not performed in the region other than the formation region of the microlens array 200 and the rim 201, the lens formation layer 20 is completely removed in this region.
Further, as shown in FIG. 5 (e), after heat treatment (firing) at a temperature equal to or higher than the softening temperature of the glass, annealing is performed, and a plurality of regions are formed in the formation region of the microlens array 200 shown in FIG. At the same time, the rim 201 is formed in the formation region of the rim 201 shown in FIG. At this time, for example, the microlens 200a is formed with a height of about 15 μm, and the rim 201 is formed with a height of about 20 μm. Since the photosensitive resin is burned away in the baking process, the microlens array 200 and the rim 201 are formed of only glass components. Adjacent microlens arrays 200 are arranged apart from each other, and adjacent rims 201 are also arranged apart from each other.

Then, the mother substrate 1000 shown in FIG. 3 in which a plurality of microlens arrays 200 and rims 201 are formed on the transparent substrate 102 can be obtained. Note that a transparent electrode 106, a TFT element 108, and an alignment film 107 are further formed on the surface of the mother substrate 1000 opposite to the surface on which the microlens 200 is formed, as shown in FIG.
At this time, adjacent microlenses 200a are coupled by a glass material forming the microlens 200a, and a coupled portion 200b is formed. At this time, for example, the height of the coupling portion 200b is formed to be about 10 μm or less. Here, when FIG. 5D is compared with FIG. 5E, it can be seen that the lens forming layer 20 contracts in the lens height direction (optical axis direction) by firing. At this time, a force that contracts in the plane direction of the microlens array 200 (the lens arrangement direction) is generated. However, since the adjacent lenses are coupled in the coupling unit 200b, they can be separated from each other. First, the contraction force in the lens arrangement direction is alleviated by a reaction force generated on the transparent substrate 102 in a direction parallel to the lens arrangement direction. Therefore, the lens does not rise upward (in the direction away from the transparent substrate 102) at the outer peripheral portion of the lens, and the lens contracts in the height direction almost uniformly, so that it is analyzed that the light condensing characteristic of the lens does not deteriorate.

  Thus, after firing, the adjacent microarrays 200 and rims 201 are arranged apart from each other, so that the coefficient of thermal expansion is between the microlens array 200 and rims 201 and the transparent substrate 102 made of glass. Even if there is a difference, it is possible to reduce the occurrence of residual stress and residual strain generated between the microlens array 200 and the transparent substrate 102 during slow cooling after firing. As a result, it is possible to suppress the warpage of the transparent substrate 102 made of glass and the occurrence of cracks in the microlens array 200 caused by the difference in thermal expansion coefficient between the transparent substrate 102 made of glass and the microlens array 200.

  Next, as shown in FIG. 3, by cutting the mother substrate 1000 along cutting lines X1-X2,..., Y1-Y1,. The mother substrate 1000 is cut into a plurality of microarray substrates 500. For example, a scriber break method is used for cutting the mother substrate 1000. In the scriber / break method, after the scribe line is formed by the scriber, the mother substrate 1000 is divided by pressurizing the scribe line with a break bar.

  Then, the outer peripheral end face and corners of each cut out microlens array substrate 500 are polished. By this polishing step, cullet generation can be prevented. At this time, since the adjacent rims 201 are separated from each other, a polishing region can be secured on the outer peripheral end surface of the microlens array substrate 500. Even if the outer peripheral end surface and corners of the microlens array substrate 500 are polished, the rim 201 is shaved. There is no end.

  Note that the mother substrate 1000 is cut not only when the mother substrate 1000 is cut alone, but also on the mother substrate 1000, which is another mother substrate (for separating the plurality of first transparent substrates 101 shown in FIG. (Not shown) when the mother substrate 1000 is cut at the same time after bonding with the sealing material 111, or the mother substrate 1000 and the other mother substrate are bonded with the sealing material 111, and both the mother substrate and the sealing material 111 are bonded. It is conceivable that both mother substrates are cut at the same time after the liquid crystal is injected and sealed in the space surrounded by. Note that the formation region of the transparent electrode 106 on the other mother substrate corresponds to the formation region of the transparent electrode 106 on the mother substrate 1000.

Embodiment 2 of the Invention
Next, a method for manufacturing a mother substrate and a microlens array substrate according to Embodiment 2 of the present invention will be described. FIG. 6 is a diagram illustrating a method of manufacturing the microlens array substrate according to the second embodiment of the present invention. FIG. 6 schematically shows a cross section in the formation region of the microlens array 200 of the mother substrate 1000 shown in FIG.
In Embodiment 1 of the present invention, a negative photoresist is used as the photosensitive resin in the photosensitive glass paste. However, in Embodiment 2 of the present invention, the photosensitive portion is decomposed and the solubility in a solvent is improved. Positive type photoresist is used.
First, as shown in FIG. 6A, a glass transparent substrate 102 is prepared. Next, as shown in FIG. 6B, a lens forming layer 20a is formed by applying and forming a photosensitive glass paste over the entire area of one side of the transparent substrate.

  Next, as shown in FIG. 6C, a gray scale mask 31 is arranged above the lens forming layer 20a, and in the formation region of the microlens array 200 shown in FIG. An area other than the formation area of the rim 201 is exposed. Here, the formation regions of the adjacent microlens arrays 200 are set apart from each other as shown in FIG. In the formation region of the microlens array 200, the intensity of exposure light irradiated from the grayscale mask 31 side is modulated by the lens formation region of the grayscale mask 31.

  More specifically, intensity modulation is applied so that the exposure intensity increases concentrically with the central portion of the lens forming area as a minimum. Due to the exposure light intensity-modulated by the lens forming region of the gray scale mask 31, the lens forming layer 20a is decomposed by a developer other than the lens shape. Further, by exposing the area other than the formation area of the microlens array 200 and the rim 201, the lens formation layer 20a is decomposed in the area other than the formation area of the microlens array 200 and the rim 201.

At this time, the gray scale mask 31 is manufactured so that the rim 201 shown in FIG. 3 can be formed simultaneously with the microlens 200a. Then, by using the gray scale mask 31 to expose the inside of the rim 201 forming region shown in FIG. 3, the portions other than the shape of the rim 201 are decomposed by the developer.
Next, as shown in FIG. 6D, after the exposure of the lens forming layer 20a is completed, the uncured portion is removed by developing the lens forming layer 20a.

  Further, after performing heat treatment (firing) at a temperature equal to or higher than the softening temperature of the glass, annealing is performed, and as shown in FIG. 6 (e), within the formation region of the microlens array 200 shown in FIG. A plurality of microlenses 200a are formed, and at the same time, the rim 201 is formed in the formation region of the rim 201 shown in FIG. Since the photosensitive resin is burned away in the baking process, the microlens array 200 and the rim 201 are formed of only glass components. Adjacent microlens arrays 200 are arranged apart from each other, and adjacent rims 201 are also arranged apart from each other.

  Then, the mother substrate 1000 shown in FIG. 3 in which a plurality of microlens arrays 200 and rims 201 are formed on the transparent substrate 102 can be obtained. At this time, adjacent microlenses 200a are coupled by a glass material forming the microlens 200a, and a coupled portion 200b is formed.

  Thus, after firing, adjacent microarrays 200 and rims 200a are spaced apart from each other, so that there is a difference in thermal expansion coefficient between the microlens array 200 and rim 201 and the transparent substrate 102. Even if it exists, the generation | occurrence | production of the residual stress and the residual distortion which arise between the microlens array 200 and the transparent substrate 102 at the time of slow cooling after baking can be reduced. As a result, it is possible to suppress the warpage of the transparent substrate 102 made of glass and the occurrence of cracks in the microlens array 200 caused by the difference in thermal expansion coefficient between the transparent substrate 102 made of glass and the microlens array 200.

The above description is for explaining the embodiment of the present invention, and the present invention is not limited to the above embodiment. Moreover, those skilled in the art can easily change, add, and convert each element of the above embodiment within the scope of the present invention.
The microlens in the above embodiment is a concept including not only a normal lens having a convex or concave shape but also a cylindrical lens, a Fresnel lens, and a prism.

In the above embodiment, the microlens array and the rim are formed of the same material. However, the microlens array and the rim may be formed of different materials. In the above embodiment, the microlens array and the rim are formed using the same gray scale mask. However, the micro lens array and the rim may be formed using different gray scale masks.
In the embodiment described above, the rim is formed on the transparent substrate. However, the rim may be produced alone or may be formed integrally on the polarizing plate side.
In the above embodiment, the microlens array substrate 500 has been described for use in a liquid crystal display device, but the present invention is not limited to this and can be used for other purposes.

It is sectional drawing which shows typically the structure of the liquid crystal display device which has a some micro lens. It is a top view when a microlens array board | substrate is seen from the microlens array formation surface side. It is a top view when a mother board | substrate is seen from the surface side in which a microlens array is formed. It is sectional drawing of the mother board | substrate in the AA cutting line of FIG. It is a figure which shows the manufacturing method of the microlens array board | substrate concerning Embodiment 1 of this invention. It is a figure which shows the manufacturing method of the micro lens array board | substrate concerning Embodiment 2 of this invention. It is a partial sectional view of a micro lens array substrate in which a micro lens array is formed on a transparent substrate.

Explanation of symbols

20, 20a Lens forming layer 100 Liquid crystal display panel 101 First transparent substrate 102 Second transparent substrate 103 Liquid crystal layer 104 Color filter layer 105 Black matrix 106 Transparent electrode 107 Alignment film 108 TFT element 109 Polarizing plate 110 Spacer 111 Sealing material 200 Microlens array 200a Microlens 201 Rim 500 Microlens array substrate

Claims (12)

A mother substrate for multi-faceting a microlens array substrate having a plurality of microlenses,
A glass substrate;
A plurality of microlens arrays formed on the glass substrate, each having a plurality of microlenses mainly composed of glass, and
Among the plurality of microlens arrays, adjacent microlens arrays are arranged apart from each other. A plurality of outer frame portions formed in a frame shape on the glass substrate along the outer peripheral edges of the plurality of microlens arrays,
The mother substrate according to claim 1, wherein among the plurality of outer frame portions, adjacent outer frame portions are arranged apart from each other.   The mother substrate according to claim 2, wherein the plurality of outer frame portions are formed of the same material as the plurality of microlens arrays.   The mother substrate according to claim 1, wherein adjacent microlenses are coupled by a glass material.   The mother substrate according to claim 1, wherein the plurality of microlens arrays are arranged in a matrix. A method of manufacturing a mother substrate for multi-faceting a microlens array substrate having a plurality of microlenses,
Forming a plurality of microlens arrays each having a plurality of microlenses mainly composed of glass on a glass substrate;
In the forming step of the plurality of microlens arrays, an adjacent microlens array among the plurality of microlens arrays is arranged apart from each other. A step of projecting a plurality of outer frame portions in a frame shape on the glass substrate along each outer peripheral edge of the plurality of microlens arrays,
The method for manufacturing a mother substrate according to claim 6, wherein in the step of forming the plurality of outer frame portions, adjacent outer frame portions among the plurality of outer frame portions are arranged apart from each other.   The method for manufacturing a mother substrate according to claim 7, wherein the plurality of microlens arrays and the plurality of outer frame portions are formed simultaneously. The step of forming the plurality of microlens arrays includes:
Forming a lens forming layer on the glass substrate containing glass powder and having a plurality of microlens shapes;
The method of manufacturing a mother substrate according to claim 6, further comprising a step of forming microlenses coupled between adjacent microlenses by firing the lens forming layer. The step of forming the lens forming layer includes:
Applying a photosensitive glass paste made of glass powder and photosensitive resin on the glass substrate;
10. The method for manufacturing a mother substrate according to claim 9, further comprising a step of forming a microlens shape having a coupled portion by exposing and developing the glass paste after application through a gray scale mask. Method. A method of manufacturing a microlens array substrate, in which a microlens array substrate having a plurality of microlenses is multi-faced from a mother substrate,
Forming a mother substrate on the glass substrate by forming a plurality of microlens arrays each having a plurality of microlenses mainly composed of glass; and
Cutting the mother substrate into a plurality of microlens array substrates,
In the mother substrate manufacturing step, among the plurality of microlens arrays, adjacent microlens arrays are arranged apart from each other,
In the cutting step of the plurality of microlens array substrates, the mother substrate is cut along a cutting line provided between the adjacent microlens arrays.   The method of manufacturing a microlens array substrate according to claim 11, further comprising a step of polishing an outer peripheral end surface of the cut microlens array substrate.

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