JP2010002925A - Micro lens array substrate and its manufacturing method, liquid crystal panel, liquid crystal projector, display, and illuminator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a microlens substrate suitable for high resolution and having a precision microlens array, a manufacturing method of the microlens array substrate for manufacturing the microlens substrate with a high yield, a liquid crystal panel having this microlens array, a liquid crystal projector, a display, and an illuminator. <P>SOLUTION: The microlens array substrate 1 includes, in the surface of a quartz substrate or a glass substrate, a microlens array 8 constituted of a plurality of continuous concave microlenses 11 and an alignment mark 7 formed outside a microlens array region, wherein the microlens array 8 and the alignment mark 7 are simultaneously formed by a transfer method through dry etching. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a microlens array substrate, a manufacturing method thereof, and a liquid crystal panel, a liquid crystal projector, a display device, and an illumination device having the microlens array substrate.

  Front AV projector devices, which have been used for business purposes, are becoming popular in consumer markets such as home theaters due to the development of low-cost liquid crystal projectors. Liquid crystal projectors are becoming more and more compact at a rapid speed, and have achieved low prices by improving the degree of integration of components. With the development of personal computers, the resolution has been improved to VGA, SVGA, XGA, and SXGA. The resolution of the liquid crystal monitor installed in the liquid crystal projector has also been improved, and the liquid crystal using the light from the light source can be used efficiently. There is a need for a microlens array substrate that projects a monitor image.

  In this microlens array substrate, the degree of integration of the microlens is improved in accordance with the resolution improvement of the liquid crystal monitor. Microlenses must handle high brightness and high definition at the same time. For example, as the panel size of a liquid crystal display element becomes smaller, the pixel size becomes smaller in proportion to this, so the microlenses themselves are also arranged. The pitch becomes smaller. Accordingly, it is necessary to make the cover glass thin.

  Conventionally, for producing such a microlens array substrate, a quartz substrate or various glass substrates are used, and applications such as a wet etching method and a 2P (Photo-Polimarization) method have been put into practical use.

  FIG. 10 shows a method for manufacturing a microlens array substrate using a wet etching method. First, as shown in FIG. 10A, a resist mask 32 having a plurality of circular openings 32a is formed on a substrate 31 made of glass or quartz so as to correspond to the microlens array. Next, as shown in FIG. 10B, a plurality of lens-shaped concave portions (spherical concave portions) 33 are formed on the surface of the substrate 31 by performing isotropic etching with an HF-based etchant through a resist mask 32. Next, after removing the resist mask 32, as shown in FIG. 10C, a resin 34 having a refractive index different from that of the substrate is applied onto the substrate 31, and the resin 34 is filled in the recesses 33. The resin 34 in the recess 33 and the substrate 31 form a microlens array 36 in which a plurality of microlenses 35 are continuously arranged. Next, as shown in FIG. 10D, a cover glass plate 37 is bonded onto the substrate 31 through the resin 34, polished to a required thickness, and a transparent electrode made of ITO (indium tin oxide), for example, is formed on the cover glass plate 37. 38 is formed to produce a microlens array substrate 39.

  FIG. 11 shows a method for manufacturing a microlens array substrate using the 2P method. First, a stamper 41 is prepared in which a microlens array shape 43 formed by arranging a plurality of microlens shapes 42 shown in FIG. 11A is integrally formed. Next, as shown in FIG. 11B, the first resin layer 45 is formed on the glass substrate 44, and the microlens array shape 42 of the stamper 41 is pressure-bonded to the resin layer 45. Next, as shown in FIG. 11C, the stamper 41 is peeled off, whereby the microlens array-shaped recess 46 is transferred to the surface of the first resin layer 45. Next, as shown in FIG. 11D, a second resin 47 having a different refractive index is applied on the first resin layer 45, and the second resin 47 is filled in the recess 46. The first resin layer 45 and the second resin 47 form a microlens array 49 in which a plurality of microlenses 48 are arranged. Next, as shown in FIG. 11E, the cover glass plate 50 is bonded onto the glass substrate 44 via the second resin 47, and the cover glass plate 50 is polished to a required thickness. Thereafter, a transparent electrode 51 of, for example, ITO (indium tin oxide) is formed on the cover glass plate 50 to produce a microlens array substrate 52.

  A method of manufacturing a microlens array substrate using the above-described wet etching method is described in Patent Document 1. A method of manufacturing a microlens array substrate using the 2P method is described in Patent Document 2.

JP 2000-231007 A Japanese Patent Laid-Open No. 9-258195

  The manufacturing method of the microlens array substrate using the 2P method described above is excellent in mass productivity because the lens shape is transferred to the resin layer 45 by the stamper 41. However, it is difficult to control the pattern size of the microlens array due to thermal shrinkage when the resin layer 45 is cured. Further, since the concave portion 46 is formed in the resin layer 45, the boundary portion between the adjacent concave portions 46, that is, the top portion 53 (see FIG. 11) is rounded without maintaining an acute angle. As a result, the boundary portion becomes a non-lens region. End up. In particular, when the microlens itself is miniaturized in order to increase the resolution, the ratio increases in the non-lens area, and it becomes difficult to form a microlens array. Further, since two types of resins are used, there are limits to heat resistance and light resistance.

  In the manufacturing method of the microlens array substrate using the wet etching method, since the isotropic etching is used, the shape of the microlens is only spherical and other microspherical microlenses cannot be formed. That is, there is no controllability of the lens shape.

  On the other hand, conventionally, the cover surface layer thickness, that is, the thickness from the resin layer at the apex of the concave lens to the surface layer of the cover glass plate is limited to 30 μm and cannot be formed thinner than this. The reason is that the resin layer cannot be thinly formed due to the effect of the viscosity of the resin when forming the resin layer (actually, a resin having a viscosity higher than 100 cp was used).

In view of the above-mentioned points, the present invention is suitable for high resolution, a microlens substrate having a precise microlens array, and a microlens array substrate manufacturing method capable of manufacturing such a microlens array substrate with a high yield. Is to provide.
The present invention provides a liquid crystal panel, a liquid crystal projector, a display device, and an illumination device having the microlens array substrate.

  The microlens array substrate according to the present invention has a microlens array composed of a plurality of continuous concave lens-shaped microlenses on the surface of a quartz substrate or a glass substrate, and an alignment mark formed outside the microlens array region. The microlens array and the alignment mark are formed simultaneously by a transfer method using dry etching.

  As a preferred embodiment according to the present invention, it is preferable to form a microlens by filling a resin layer having a refractive index different from that of a quartz substrate or a glass substrate into a lens-shaped recess formed on the surface of the quartz substrate or the glass substrate. For example, by filling a lens-shaped recess with a resin having a refractive index larger than that of a quartz substrate or a glass substrate, light incident from the glass substrate side is refracted at the boundary between the glass substrate and the resin layer, and serves as a condenser lens. Can have a function. The microlens array is preferably formed with no non-lens area at the boundary between adjacent microlenses. The microlens can be formed in a spherical shape or an aspherical shape. A cover glass member having a required thickness is bonded to the surface side on which the microlens array is formed. The cover surface layer thickness from the apex of the microlens to the cover glass surface is preferably 30 μm or less, and the resin layer thickness is preferably 10 μm or less. It is preferable that a light shielding layer is formed on the surface of the cover glass member at a position corresponding to the boundary portion between the adjacent microlenses. Furthermore, it is preferable that a transparent protective layer is formed on the surface of the cover glass member so as to cover the light shielding layer.

The liquid crystal panel according to the present invention has the microlens array substrate described above.
A liquid crystal projector according to the present invention has the microlens array substrate.
A display device according to the present invention includes the microlens array substrate.
An illumination device according to the present invention includes the above-described microlens array substrate.

  The method of manufacturing a microlens array substrate according to the present invention includes forming a resist layer having a plurality of continuous lens-shaped recesses and a groove pattern on a surface of a quartz substrate or a glass substrate, dry-etching the resist layer, and A microlens array and an alignment mark are simultaneously formed by transferring the concave and groove patterns onto the surface of a quartz substrate or a glass substrate.

  The method of manufacturing a microlens array substrate according to the present invention includes forming a resist layer having a plurality of continuous lens-shaped recesses and a groove pattern on a surface of a quartz substrate or a glass substrate, dry-etching the resist layer, and The concave and groove patterns are transferred to the surface of the quartz substrate or glass substrate to form the microlens array and the alignment mark at the same time, and the refractive index different from the quartz substrate or glass substrate is formed in the lens-shaped recess on the quartz substrate or glass substrate surface. The resin is injected.

  The method of manufacturing a microlens array substrate according to the present invention includes forming a resist layer having a plurality of continuous lens-shaped recesses and a groove pattern on a surface of a quartz substrate or a glass substrate, dry-etching the resist layer, and The concave and groove patterns are transferred to the surface of the quartz substrate or glass substrate to form the microlens array and the alignment mark at the same time, and the refractive index different from the quartz substrate or glass substrate is formed in the lens-shaped recess on the quartz substrate or glass substrate surface. The resin is injected, the cover glass member is bonded together, and the cover glass member is polished to a required thickness.

  As a preferred embodiment of the method for manufacturing the microlens array substrate having the cover glass member, a light shielding layer is formed at a position that coincides with a boundary portion of adjacent microlenses on the surface of the cover glass member. It is preferable to form a transparent protective layer so as to cover the light shielding layer. Polish the cover glass member so that the film thickness of the resin from the top of the microlens to the cover glass member is 10 μm or less, and the cover surface layer thickness from the top of the microlens to the surface of the cover glass member is 30 μm or less. Is preferred.

  As a preferred embodiment of the manufacturing method of the microlens array substrate, a plurality of continuous lens-shaped concave portions of the resist layer are formed without a non-lens region.

  According to the microlens array substrate of the present invention, a plurality of continuous concave lens-shaped microlens arrays are directly formed on the surface of a quartz substrate or glass substrate by a transfer method using dry etching, which is suitable for high resolution. It is possible to provide a microlens array substrate having a precise microlens array with good pattern dimensional accuracy. Since the alignment mark formed by the transfer method at the same time as the microlens array is provided outside the microlens array area on the surface of the quartz substrate or glass substrate, an alignment mark with high positional accuracy can be obtained, and the alignment in the subsequent process can be accurately performed. It can be carried out. Further, since it is not necessary to form this alignment mark in a separate process, the manufacturing process can be simplified.

  Since the microlens array is formed by filling a resin layer having a different refractive index into a lens-shaped recess formed on the surface of a quartz substrate or glass plate, the structure can be simplified with less material used. The boundary portion between adjacent microlenses is formed without a non-lens region, and the boundary portion is also formed as a lens region, so that a microlens array substrate with high light collection efficiency is obtained. Since the microlens array can be formed as a spherical surface or aspherical surface as a lens curved surface, it is possible to provide a microlens array substrate having a lens curved surface suitable for the purpose.

  When a cover glass member having a required thickness is bonded to the surface side on which the microlens array is formed, for example, when used in a liquid crystal panel, the formation of a transparent electrode and an alignment film is improved. By forming the light shielding layer at a position corresponding to the boundary portion between the adjacent microlenses 11 on the surface of the cover glass plate, the light shielding layer is formed at a position closest to the microlens. By having such a light shielding layer, for example, when a liquid crystal panel is configured, even if stray light components are generated by irradiating light to the sharp apex of the boundary between adjacent microlenses, the light shielding layer causes the stray light components Can be reliably prevented from entering the TFT circuit side.

By forming the transparent protective layer by covering the light shielding layer on the surface of the cover glass member, the light shielding layer can be prevented from being oxidized even if the light shielding layer is formed of an easily oxidizable member such as Al. Further, since the transparent protective layer functions as an antireflection film, the light transmittance can be improved.
Even if the microlens becomes finer as the resolution increases, the cover surface layer thickness from the top of the microlens to the surface of the cover glass is 30 μm or less and the resin layer is 10 μm or less. Can be focused on the target area. That is, the lens focal depth of the microlens that has been miniaturized can be adjusted to the target region.

According to the liquid crystal panel according to the present invention, since the microlens array substrate is provided, a high-resolution and highly reliable liquid crystal panel can be provided.
According to the liquid crystal projector according to the present invention, since the microlens array substrate is provided, a high-resolution and highly reliable liquid crystal projector can be provided.
According to the display device according to the present invention, since the microlens array substrate is provided, a display device with high resolution and high reliability, with improved luminance, or with a wide viewing angle can be provided.
According to the illuminating device of the present invention, since the microlens array substrate is provided, an illuminating device with improved brightness can be provided.

  According to the method for manufacturing a microlens array substrate according to the present invention, the lens-shaped concave portion of the resist layer is transferred to the surface of the quartz substrate or the glass substrate by dry etching to form the microlens array. Since the quartz substrate or the glass substrate does not undergo dimensional changes during the process, a microlens array with good pattern dimensional accuracy can be formed. In addition, since the alignment mark is formed simultaneously by transferring the groove pattern of the resist layer to the surface of the quartz substrate or the glass substrate simultaneously with the transfer of the lens-shaped recess, the alignment mark 7 with high positional accuracy can be formed. The subsequent mask alignment of the stepper device can be performed with high accuracy.

  According to another method for manufacturing a microlens array substrate according to the present invention, a lens-shaped concave portion and a groove pattern of a resist layer are transferred onto a surface of a quartz substrate or a glass substrate by dry etching, so that a microlens array and an alignment mark are transferred. At the same time, a microlens array is formed by injecting a resin layer having a different refractive index into a lens-shaped recess of a quartz substrate or a glass substrate. This manufacturing method has the same effects as the manufacturing method described above, such as the ability to form a microlens array with good pattern dimensional accuracy and an alignment mark with high positional accuracy. Furthermore, since a microlens array is formed by injecting a resin layer into a lens-shaped recess of a quartz substrate or a glass substrate, it is possible to manufacture a microlens array substrate with a simple structure with fewer materials and fewer steps. it can. Since only one type of resin layer is used as the resin layer, it is excellent in heat resistance and light resistance.

  According to still another method for manufacturing a microlens array substrate according to the present invention, the lens-shaped concave portion and groove pattern of the resist layer are transferred to the surface of the quartz substrate or the glass substrate by dry etching, so that the lens shape of the quartz substrate or the glass substrate After injecting a resin layer having a different refractive index into the recess and bonding the cover glass member, the cover glass member is polished to a required thickness. This manufacturing method has the same effects as the manufacturing method described above, such as the ability to form a microlens array with good pattern dimensional accuracy and an alignment mark with good positional accuracy. Further, after the cover glass member is bonded, the cover glass member is polished to a required thickness, thereby enabling the subsequent formation of a light shielding layer.

By forming the light shielding layer at a position that coincides with the boundary portion between adjacent microlenses on the surface of the cover glass member, the light shielding layer can be formed at a position closest to the microlens array. Therefore, for example, when a liquid crystal panel is constructed, even if a steep light component is generated by irradiating light to the sharp apex of the boundary portion between adjacent microlenses, the stray light component is incident on the TFT circuit side by this light shielding layer. Ensure prevention.
In addition, by forming the alignment mark with the above positional accuracy on the surface of the quartz substrate or the glass substrate, the light shielding layer can be precisely formed at the position of the boundary portion between the adjacent microlenses. Further, the alignment mark forming process is not required separately, and the process can be simplified.

  By forming the transparent protective layer so as to cover the light shielding layer, even if the light shielding layer is formed of a material that is easily oxidized such as Al, the light shielding layer is not oxidized over a long period of time, and stray light can be blocked. Incidentally, when the light shielding layer is oxidized, pinholes are easily generated in the light shielding layer, and the reliability as the light shielding layer is lowered. In the subsequent steps, the counter electrode and the like can be formed without worrying about the oxygen atmosphere. Furthermore, since the transparent protective layer acts as an antireflection film, it is possible to manufacture a microlens array substrate with better light transmittance.

  A microlens is made with high resolution by polishing the cover glass member so that the thickness of the resin layer is 10 μm or less and the cover surface layer thickness from the top of the microlens to the surface of the cover glass member is 30 μm or less. Even when the size of the lens is miniaturized, it can be adjusted to the focal depth of the lens, and a microlens array substrate corresponding to high resolution can be manufactured.

  Since the lens-shaped concave portion of the resist layer is formed in a continuous state without a non-lens region, the lens boundary portion of the lens-shaped concave portion after transfer onto the quartz substrate or the glass substrate can be formed as a lens region. Therefore, it is possible to form a microlens array with good light collection efficiency.

AE is process drawing (the 1) which shows 1st Embodiment of the manufacturing method of the microlens board | substrate which concerns on this invention. F to I are process diagrams (part 2) illustrating the first embodiment of the method of manufacturing the microlens substrate according to the present invention. A to D are process diagrams (part 1) illustrating a second embodiment of a method for manufacturing a microlens substrate according to the present invention. EG is process drawing (the 2) which shows 2nd Embodiment of the manufacturing method of the micro lens board | substrate which concerns on this invention. It is sectional drawing which shows 3rd Embodiment of the manufacturing method of the microlens board | substrate which concerns on this invention. It is a pattern figure which shows the exposure mask of a multiple exposure method. It is an enlarged view of the principal part of a micro lens array board | substrate. A to B are process diagrams (part 1) showing an embodiment of a method of manufacturing a liquid crystal panel for a liquid crystal projector manufactured using the microlens array substrate according to the present invention. It is process drawing (the 2) which shows one Embodiment of the manufacturing method of the liquid crystal panel for liquid crystal projectors manufactured using the micro lens array board | substrate which concerns on this invention. A to D are methods of manufacturing a microlens array substrate using a conventional wet etching method. A to E are methods for manufacturing a microlens array substrate using a conventional 2P method.

Embodiments of the present invention will be described below with reference to the drawings.
<First embodiment>
1 and 2 show an embodiment of a microlens array substrate and a manufacturing method thereof according to the present invention. In this example, a microlens array substrate for a liquid crystal panel constituting a liquid crystal projector will be described.
First, as shown in FIG. 1A, a parallel plate quartz substrate or glass substrate, which is a transparent substrate, in this example, a quartz substrate 2 is prepared. A photoresist layer 3a having a required thickness is formed on the surface of the parallel plate quartz substrate. In this example, the photoresist layer 3a is formed by spin coating.

  Next, as shown in FIG. 1B, a photolithographic process (pattern exposure, development process) is performed on the photoresist layer 3a, whereby a plurality of continuous microlens-shaped concave shapes that become the prototype of the microlens array are formed on the surface. A resist layer having a curved surface (hereinafter referred to as a lens-shaped recess) 4 and a vertical groove pattern 5 corresponding to an alignment mark for a stepper located outside a display region (a region of the lens-shaped recess 4 serving as a so-called microlens array) 3b is formed. In this photolithography process, as shown in FIG. 6, pattern exposure 62 is sequentially performed on the photoresist layer 3a using a plurality of exposure masks (multiple masks) 61 [611, 612, 613, 614, 615]. A multiple exposure method that performs [621, 622, 623, 624, 625] is used. The exposure amount increases in the order of pattern exposures 621 to 625. Multiple exposure can be performed using, for example, an i-line stepper device. Development processing is performed after this multiple exposure. By this multiple exposure method, the curved surface shape of the lens-shaped recess 4 can be arbitrarily controlled, and it is possible to form, for example, a spherical shape or an aspherical shape that matches the target lens shape.

Next, as shown in FIG. 1C, the lens-shaped concave portion 4 and the vertical groove pattern 5 formed on the surface side of the resist layer 3b are formed on the quartz substrate 2 by dry etching by anisotropic etching from the resist layer 3b. Transfer to the surface. In this dry etching, an etching gas that selects the same etching selectivity between the resist layer 3b and the quartz substrate 2 is selected. As an etching gas, for example, a gas such as CF ₄ , CF ₃ H, CH ₂ H ₂ , C ₃ F ₈ , SF ₆ can be used. By this dry etching, a plurality of continuous lens-shaped concave portions 6 serving as a microlens array and a vertical groove-shaped alignment mark 7 for a stepper located on the outside thereof are formed on the surface of the quartz substrate 2. In this case, the entire surface of each curved surface of each lens-shaped recess 6 is formed into a lens shape. Therefore, at the boundary portion between the adjacent lens-shaped recesses 6, the apex 18 is sharp so that both curved surfaces are abutted.

  Next, as shown in FIG. 1D, a resin layer 9 having a refractive index different from that of the quartz substrate 2 is formed on the surface of the quartz substrate 2 so as to be filled in the lens-shaped recess 6 and the alignment mark 7 for the stepper. A parallel flat cover glass plate 10 having a required thickness d1 is bonded onto the resin layer 9 that has been formed. As the resin layer 9 here, a resin having a refractive index larger than that of the quartz substrate 2 is used. As the resin layer 9, for example, episulfide type, other epoxy type, acrylic type resin can be used. In this example, for example, a thermosetting resin 9 is injected onto the surface of the quartz substrate 2, that is, in a state where the resin glass 9 is dripped and placed on the cover glass plate 10. Fill inside. Thereafter, the cover glass plate 10 is bonded to the quartz substrate 2 by thermosetting. A microlens array 8 in which a plurality of microlenses 11 are continuously arranged is formed by the quartz substrate 2 and the resin layer 9 filled in the lens-shaped recess 6. The continuous microlenses 11 constituting the microlens array 8 are continuous microlenses having no non-lens area at the boundary between adjacent microlenses 11. At the same time, the alignment mark 7 in which the longitudinal groove pattern 5 is filled with the resin layer 9 is formed outside the microlens array region.

  Next, as shown in FIG. 1E, the cover glass plate 10 is polished to reduce the cover surface thickness d2 from the top of the concave microlens to the cover glass surface. The cover surface layer thickness d2 can be 5 μm or more and 30 μm or less, preferably less than 20 μm, more preferably 10 μm or less. Further, the thickness d3 of the resin layer 9 from the apex of the microlens to the back surface of the cover glass can be set to 1 μm or more and 10 μm or less. The viscosity of the resin at this time may be 1 cp or more and 100 cp or less. In this example, a resin having a viscosity of about 30 cp is used.

  Here, when the cover surface layer thickness d2 exceeds 30 μm, when the microlens 11 is miniaturized as the resolution is increased, the depth of focus of the microlens 11 cannot be adjusted to the target position, so Light efficiency decreases. As d2 is reduced to less than 20 μm and 10 μm or less, the microlens can be further miniaturized. The cover surface layer thickness d2 is 5 μm, which is a lower limit for manufacturing, in consideration of variation in the thickness d2 in the substrate surface. On the other hand, it is desirable to make the thickness d3 of the resin layer 9 as thin as possible, but 1 μm is the lower limit for making a microlens with good reproducibility. If the thickness d3 exceeds 10 μm, the cover surface layer thickness d2 will be affected, making it difficult to achieve high resolution when applied to a liquid crystal panel or the like.

  Next, as shown in FIG. 2F, a light shielding film made of a metal film or the like that becomes a so-called black matrix, in this example, an aluminum (Al) film 13 is formed on the cover glass plate 10 by vapor deposition or sputtering.

  Next, as shown in FIG. 2G, a portion of the aluminum film 13 corresponding to the alignment mark 7 is removed by selective etching so that the alignment mark 7 formed on the quartz substrate 2 can be read, and an opening (so-called marker window) is obtained. ) 14 is formed. The opening 14 can be formed with rough accuracy.

  Next, as shown in FIG. 2H, alignment with the exposure mask of the i-line stepper apparatus is performed with reference to the alignment mark 7, and the black film 15 is formed by patterning the aluminum film 13 by selective etching using a lithography technique. To do. As shown in FIG. 7, the black matrix 15 is formed in a lattice pattern so as to leave a boundary portion between the continuous microlenses 11. In this case, since the alignment mark 7 is formed on the quartz substrate 2, the position of the alignment mark 7 can be obtained with high accuracy. Therefore, when the microlens 11 has a substantially square shape with a side of 10 μm, for example, the black matrix 15 is ± It can be formed with an alignment accuracy of about 1 μm. At the time of patterning the black matrix 15, an alignment mark 16 made of an aluminum film 13, that is, an alignment mark 16 for bonding a so-called TFT substrate on which a pixel electrode and a thin film transistor (TFT) constituting a liquid crystal panel described later are formed.

  Next, as shown in FIG. 2I, a counter electrode 17 made of a transparent conductive film, for example, an ITO (indium tin oxide) film is formed on the cover glass plate 10 on which the black matrix 15 and the alignment mark 16 are formed. A parallel plate microlens array substrate 1 is obtained. Note that the pixel pitch of the microlens array substrate 1 in the present embodiment is a high-definition one of 10 μm × 10 μm.

  According to the microlens array substrate 1 according to the above-described embodiment, the lens-shaped recess 6 is directly formed on the surface of the quartz substrate 2 by a transfer method using dry etching, and the lens-shaped recess is filled with resin. A microlens array 8 composed of a plurality of microlenses 11 arranged in series is directly formed in the surface of the quartz substrate 2. In this configuration, since the microlens array 8 is formed directly in the surface of the quartz substrate, it is possible to provide the microlens array substrate 1 having the precise microlens array 8 with good pattern dimensional accuracy.

Further, the boundary portion between the adjacent microlenses 11 is formed with no non-lens region. That is, since the lens-shaped concave portion 6 is formed in the quartz substrate 2, the boundary portion is formed as a sharp apex 18 without falling, and the boundary portion is also formed as a lens region. Therefore, a microlens array substrate with high light collection efficiency is obtained.
Since the microlens array 8 is formed using the multiple exposure method, a spherical surface or an aspherical surface can be obtained as a lens curved surface, and a microlens array substrate having a lens curved surface suitable for the purpose can be provided.

Since the quartz substrate 2 is integrally provided with the lens-shaped recess 6 and the alignment mark 7 for the stepper, the alignment mark 7 with high positional accuracy can be obtained. Further, it is not necessary to form in a separate process, and the manufacturing process can be simplified.
A cover glass plate 10 having a required thin thickness is formed on the surface side where the microlens array 8 is formed, and a black matrix 15 is formed on the surface of the cover glass plate 10 at a position corresponding to the boundary portion of the adjacent microlenses 11. By being formed, the black matrix 15 is formed at a position closest to the microlens 11. By having such a black matrix 15, when a liquid crystal panel is configured, even if stray light components are generated by irradiating light to the sharp apex of the boundary portion between adjacent microlenses 11, the black matrix 15 The stray light component can be reliably prevented from entering the TFT circuit side.
The cover surface layer thickness d2 is reduced to 5 μm or more and 30 μm or less, and the resin thickness d3 is reduced to 1 μm or more and 5 μm or less, so that the light is condensed in the target region even when the microlens 11 is miniaturized as the resolution increases. Can be made. That is, the lens focal depth of the microlens 11 that has been miniaturized can be adjusted to the target region. That is, the degree of freedom in designing the optical path increases.

  According to the method for manufacturing a microlens array substrate according to the present embodiment, the lens-shaped recess 6 is formed by transferring the lens-shaped recess 4 of the resist layer 3b to the surface of the quartz substrate 2 by dry etching. The microlens array 8 is formed by filling the resin layer 9 in the recess 6. The quartz substrate 2 itself does not shrink like the resin layer, and the microlens array 8 with good pattern dimensional accuracy can be formed. Further, since the lens-shaped recess 6 is directly transferred to the quartz substrate 2, the lens boundary portion between the adjacent microlenses 11 can be used as a lens region. That is, since the lens-shaped recess 6 is not deformed at the boundary portion between the adjacent microlenses, the microlens array 8 having no non-lens area can be formed. Therefore, it is possible to form the microlens array 8 with good light collection efficiency.

  As the exposure for forming the lens-shaped recess 4 on the surface of the photoresist layer 3a, the curved surface shape of the lens-shaped recess 4 can be arbitrarily controlled by using a multiple exposure method. That is, the lens curved surface and the lens depth of the microlens array 8 can be designed freely and arbitrarily, and the spherical or aspherical lens-shaped recess 6 is formed on the surface of the quartz substrate 2 according to the purpose. Can do. Therefore, the controllability of the lens shape is excellent.

  Since the alignment mark 7 for the stepper is formed simultaneously with the transfer of the lens-shaped recess 6 on the surface of the quartz substrate 2, the alignment mark 7 having a high positional accuracy can be formed, and the mask alignment of the stepper device can be performed with high accuracy. Thereby, the black matrix 15 can be precisely formed in a portion corresponding to the boundary between the adjacent microlenses 11. Further, the alignment mark forming process is not required separately, and the process can be simplified.

  The cover glass plate 10 can be formed as thin as a cover surface layer thickness d2 of 5 μm or more and 30 μm or less, and a resin thickness d3 of 1 μm or more and 10 μm or less. Therefore, even when the microlens 11 is miniaturized as the resolution increases. The cover glass plate 10 can be made thin according to the depth of focus, and the microlens array substrate 1 corresponding to high resolution can be manufactured.

  In the microlens array substrate 1, a black matrix 15 is integrally formed on the surface of the cover glass plate 10 closest to the microlens array 8. Moreover, the black matrix 15 is formed so as to match the apex 18 of the continuous lens-shaped recess 6. Thus, when a liquid crystal panel is configured, even if stray light components are generated by the light incident on the sharp apex 18 at the boundary portion between the adjacent microlenses 11, the incidence to the TFT circuit side is surely prevented. I'm going.

  Since only one type of resin layer 9 is used as the resin layer, the resin layer is excellent in heat resistance and light resistance. Since the microlens array 8 is formed by filling the lens-shaped recess 6 of the quartz substrate 2 with the resin layer 9, it is possible to manufacture the microlens array substrate 1 having a simple structure with a small amount of materials and processes. it can.

  In the manufacturing method of the microlens array substrate according to the above-described embodiment, the multiple exposure method is applied. However, as the pattern exposure by the photolithography technique, the multiple exposure method is used in accordance with the lens shape in one mask. You may carry out by the gray mask method of exposing using what is called a gray mask which changed the light transmittance toward the periphery from the center.

<Second Embodiment>
Next, FIGS. 3 to 4 show other embodiments of the microlens array substrate and the manufacturing method thereof according to the present invention. This example is also a case where the present invention is applied to a microlens array substrate for a liquid crystal panel constituting a liquid crystal projector.
In the present embodiment, the steps from FIG. 3A to FIG. 3C are the same as the steps from FIG. 1A to FIG.

  In the present embodiment, after the step of FIG. 3C, as shown in FIG. 3D, an alignment mark 16 for attaching the TFT substrate is formed on the surface of the quartz substrate 2. For example, as described above, for example, an aluminum film is formed on the entire surface of the quartz substrate 2, and the aluminum film is selectively removed by etching at a portion corresponding to the alignment mark 7 for the stepper to form an opening. Next, alignment with the exposure mask of the i-line stepper device is performed using the alignment mark 7 as a reference, and the alignment mark 16 is formed by patterning the aluminum film by selective etching using a lithography technique.

  Next, as shown in FIG. 4E, a resin layer 9 having a refractive index different from that of the quartz substrate 2 is formed on the surface of the quartz substrate 2 so as to be filled in the lens-shaped recess 6 and the alignment mark 7 for the stepper. A parallel flat cover glass plate 10 having a required thickness d1 is bonded onto the resin layer 9 that has been formed. As the resin layer 9 here, a resin having a refractive index larger than that of the quartz substrate 2 is used. In this example, for example, a thermosetting resin 9 is dropped on the surface of the quartz substrate 2 and the cover glass plate 10 is placed, and spin rotation is performed to fill the resin 9 into the lens-shaped recess 6 and the alignment mark 7. . Thereafter, the cover glass plate 10 is bonded to the quartz substrate 2 by thermosetting. A microlens array 8 in which a plurality of microlenses 11 are continuously arranged is formed by the quartz substrate 2 and the resin layer 9 filled in the lens-shaped recess 6. The continuous microlenses 11 constituting the microlens array 8 are continuous microlenses having no non-lens area at the boundary between adjacent microlenses 11. At the same time, the alignment mark 7 in which the longitudinal groove pattern 5 is filled with the resin layer 9 is formed outside the microlens array region.

  Next, as shown in FIG. 4F, the cover glass plate 10 is polished to reduce the cover surface thickness d2 from the top of the microlens to the cover glass surface. As described above, the cover surface layer thickness d2 may be 5 μm or more and 30 μm or less, preferably less than 20 μm, more preferably 10 μm or less. Moreover, as thickness d3 of the resin layer 9, it can be set as the thickness of 1 micrometer or more and 10 micrometers or less. The viscosity of the resin may be 1 cp or more and 100 cp or less. In this example, a resin having a viscosity of 30 cp is used.

  Next, as shown in FIG. 4G, a counter electrode 17 made of a transparent conductive film, for example, an ITO (indium tin oxide) film is formed on the cover glass plate 10 to obtain a target microlens array substrate 71.

  In the microlens array substrate 71 and the manufacturing method thereof according to the present embodiment, other configurations and manufacturing methods are the same as those of the microlens array substrate 1 except that the black matrix is not formed on the cover glass plate 10. is there. Therefore, the microlens array substrate 71 and the manufacturing method thereof according to the present embodiment also have the same effects as the above-described microlens array substrate 1 except for the black matrix effect.

<Third Embodiment>
FIG. 5 shows a third embodiment of a microlens array substrate 81 according to the present invention.
This example is also a case where the present invention is applied to a microlens array substrate for a liquid crystal panel constituting a liquid crystal projector.
In the present embodiment, the steps from FIG. 1A to FIG.

  In the present embodiment, after the step of FIG. 2H, as shown in FIG. 5, a transparent protective layer such as a silicon oxide film (SiO 2 film) 19 is formed on the cover glass plate 10 on which the black matrix 15 and the alignment mark 16 are formed. And a counter electrode 17 made of a transparent conductive film, for example, an ITO (indium tin oxide) film, is formed as an upper layer to obtain a target parallel flat microlens array substrate 81.

  In the microlens array substrate and the manufacturing method thereof according to the present embodiment, except that the silicon oxide film 19 is formed on the cover glass plate 10 on which the black matrix 15 and the alignment mark 16 are formed, The configuration and the manufacturing method are the same as those of the microlens array substrate 1 described above. According to the present embodiment, for example, by covering the black matrix 15 and the alignment mark 16 formed of Al with the silicon oxide film 19, the oxidation of Al can be prevented and used as the black matrix 15 over a long period of time. be able to. In addition, the silicon oxide film 19 serving as a transparent protective layer acts as an antireflection film, can increase the light transmittance, and improve the light collection efficiency. In addition, the microlens array substrate and the manufacturing method thereof according to the present embodiment also have the same effects as the microlens array substrate 1 described above.

Next, a liquid crystal panel for a liquid crystal projector manufactured using the microlens array substrate 81 described above with reference to FIGS. 8 and 9 will be described.
As shown in FIG. 8A, the microlens array substrate 81 obtained in FIG. 5 is divided by a dividing line (not shown) to form a microlens array substrate 101 corresponding to each liquid crystal panel. That is, the cover glass plate 10 is bonded to the quartz substrate 2 on which the microlens array 8 composed of a plurality of continuous microlenses 11 is formed by filling the resin-like layer 9 in the lens-like concave portion 6 on the surface side, and the cover glass plate A microlens array substrate 101 is prepared in which a grid-like black matrix 15 is formed on the substrate 10, and a silicon oxide film 19 as a transparent protective layer and a counter electrode 17 are further formed.

  On the other hand, as shown in FIG. 8B, a TFT substrate 102 on which a thin film transistor (TFT) and a pixel electrode are formed is formed on a transparent substrate on which a microlens array is formed using the same manufacturing method. That is, a resin layer having a refractive index different from that of the quartz substrate 112 is formed on the lens-shaped recess 116 by using a process similar to that shown in FIGS. A microlens array 118 including a plurality of continuous microlenses 117 filled with 119 is formed. Further, a cover glass plate 120 polished to a required thickness is bonded onto the resin layer 119. A grid-like black matrix 121 serving as a light shielding film similar to that described above with reference to FIG. 2H is formed on the cover glass plate 120 so as to surround each microlens 117, that is, along the periphery of each pixel region. Next, after a silicon oxide film 122 as a transparent protective layer is formed on the cover glass plate 120 in a state where the black matrix 121 is embedded, the surface of the interlayer insulating film 126 is planarized by, for example, a CMP (Chemical Mechanical Polishing) method. Next, a semiconductor thin film 123 made of polycrystalline silicon is selectively formed. The semiconductor thin film 123 is made amorphous by implanting Si ions, and then heat-treated and solid-phase grown to be polycrystallized.

  Next, a capacitor upper electrode 125 is formed on the semiconductor thin film 123 via the gate insulating film 124. Next, after forming the interlayer insulating film 126, a signal line 127 connected to one source / drain region of the semiconductor thin film 123 is formed, and a lead line 128 is formed in the other source / drain region. Next, an interlayer insulating film 129 is formed, and a wiring pattern 130 connected to the lead line 128 is formed. Further, an interlayer insulating film 131 is formed, and a pixel electrode 132 connected to the lower wiring pattern 130 is formed on the interlayer insulating film 131. Each of the interlayer insulating films 126, 129, and 131 can be formed of, for example, a silicon oxide film. In this manner, the TFT substrate 102 provided with the thin film transistor (TFT) circuit 133 for driving the pixel electrode 132 is manufactured.

  Then, as shown in FIG. 9, the microlens array substrate 101 and the TFT substrate 102 are aligned with respect to the alignment mark 16 (see FIG. 2H) formed on the microlens array substrate 101 side as described above, so that a required space is obtained. A liquid crystal panel 140 is manufactured by injecting the liquid crystal 135 into the space and sealing it. The liquid crystal panel 140 is a so-called double microlens liquid crystal panel having microlens arrays 8 and 118 on both substrates 101 and 102. Although not shown, alignment films are formed on the surface of the counter electrode 17 of the microlens array substrate 102 and the surface of the TFT substrate 102 on the pixel electrode 132 side, respectively.

  According to the liquid crystal panel 140, the microlens arrays 8 and 118 of the microlens array substrate 101 and the TFT substrate 102 are directly formed on the surfaces of the quartz substrates 2 and 112 by a transfer method using dry etching, so that the accuracy is high. You will have a good precision microlens array. In addition, since the lens-shaped concave portions are formed on the quartz substrates 2 and 112 by the transfer method, the boundary portion between the adjacent microlenses 11 and the boundary portion between the adjacent microlenses, that is, the apex portions of the lenses do not come off. Formed with regions. That is, the microlens arrays 8 and 118 having no non-lens area are formed. By having the microlens arrays 8 and 118 with high accuracy, light can be efficiently condensed on each pixel. Further, since the black matrix 15 is formed at the position corresponding to the boundary portion of each microlens 11 on the microlens array substrate 102 side, incident light is irradiated to the boundary portion, that is, the edge portion of the lens, and stray light components are generated. However, this stray light component is shielded by the black matrix 15 and can be prevented from entering the TFT circuit 133 side. As a result, it is possible to prevent image quality problems such as occurrence of light leakage current, flicker, and contrast reduction.

  Since the liquid crystal panel 140 of the present embodiment uses the above-described microlens array substrate 101, even when the microlens itself is miniaturized for high resolution, there is no non-lens area as the microlens array. This effectively acts as a microlens array, and can improve the light collection efficiency. Further, by making the cover surface layer thickness as thin as 5 μm or more and 30 μm or less and the resin layer thickness as 1 μm or more and 10 μm or less, it is possible to form a micro lens having a short focal length. Therefore, a liquid crystal panel for a liquid crystal projector with high resolution and high reliability can be provided.

In the above liquid crystal panel, the microlens array substrate 81 is used. However, the microlens array substrate 81 shown in FIG. 2I may be used. Moreover, it can comprise using the microlens array board | substrate 71 of FIG. 4G. In this case, a black matrix serving as a light shielding film for preventing light from entering the TFT circuit 133 is formed on the interlayer insulating film 129 in FIG.
In addition, a TFI substrate having a configuration in which the microlens array 118 is omitted as a TFT substrate can be used to form a liquid crystal panel in combination with the microlens array substrate of the present invention.

  In the above example, the microlens array substrate according to the present invention is applied to a liquid crystal panel. However, in order to improve the luminance or expand the viewing angle, plasma display (PDP), organic EL monitor, field emission (FPD), etc. The display device can also be used by changing the refractive index and shape of the lens array. Furthermore, the microlens array substrate of the present invention can be applied to a lighting device.

  That is, in the present invention, a liquid crystal panel, a liquid crystal projector, a display device, and an illumination device having the above-described microlens array substrate can be configured. The present invention can provide a liquid crystal panel and a liquid crystal projector with high resolution and high reliability. The present invention can provide a display device with high resolution and high reliability, with improved luminance or an increased viewing angle. In the present invention, an illumination device with improved luminance can be provided.

  1 .. Microlens array substrate, 2 .. Quartz substrate, 3a .. Photoresist layer, 3b .. Resist layer, 4 .. Lens-shaped recess, 5 .. Vertical groove pattern, 6 .. Lens-shaped recess, 7 Alignment mark, 8 ... Micro lens array, 9 ... Resin layer, 10 ... Cover glass plate, 11 ... Micro lens, 13 ... Aluminum film, 14 ... Opening, ... 15 Black matrix, 16 ... Alignment mark, 17 ... Counter electrode, 18 ... Sharp apex, 31 ... Substrate, 32 ... Resist mask, 32a ... Opening, 33 ... Recess, 34 ... Resin, 35 ... Micro lens, 36 ..Microlens array 37..Cover glass plate 38..Transparent electrode 39..Microlens array substrate 41..Stamper 42..Microlens shape, 3 .. Microlens array shape, 44 ... Glass substrate, 45 ... First resin layer, 46 ... Recess, 47 ... Second resin, 48 ... Multiple microlens, 49 ... Microlens array , 50 .. Cover glass plate, 51 .. Transparent electrode, 52 .. Micro lens array substrate, 61 [611, 612, 613, 614, 615] .. Exposure mask (multiple mask), 62 [621, 622, 623 , 624, 625] ... Pattern exposure, 71, 81 ... Micro lens array substrate, 102 ... TFT substrate, 112 ... Quartz substrate, 116 ... Lens-shaped recess, 117 ... Micro lens, 118 ... Micro lens Array, 119, ... Resin layer, 120, Cover glass plate, 121, Black matrix, 122, Silicon oxide film, 123, Semiconductor Thin film, 124, gate insulating film, 125, upper electrode, 126, interlayer insulating film, 127, signal line, 128, lead wire, 129, interlayer insulating film, 130, wiring pattern, 131 Interlayer insulating film, 132 .. pixel electrode, 133 .. Thin film transistor (TFT) circuit, 140 .. liquid crystal panel

Claims (19)

In the surface of the quartz substrate or the glass substrate, having a microlens array composed of a plurality of continuous concave lens-shaped microlenses, and an alignment mark formed outside the microlens array region,
The microlens array substrate and the alignment mark are simultaneously formed by a transfer method using dry etching. The lenticular recess formed on the surface of the quartz substrate or glass substrate is filled with a resin layer having a refractive index different from that of the quartz substrate or glass substrate to form the microlens. 1. The microlens array substrate according to 1. The microlens array substrate according to claim 1 or 2, wherein the microlens array is formed without a non-lens region at a boundary portion between adjacent microlenses. The microlens array substrate according to any one of claims 1 to 3, wherein the microlens is formed in a spherical shape or an aspherical shape. The microlens array substrate according to any one of claims 1 to 4, wherein a cover glass member having a required thickness is bonded to the surface side on which the microlens array is formed. The microlens array substrate according to claim 5, wherein a light shielding layer is formed on the surface of the cover glass member at a position corresponding to a boundary portion between the adjacent microlenses. The microlens array substrate according to claim 6, wherein a transparent protective layer is formed on the surface of the cover glass member so as to cover the light shielding layer. 8. The micro according to claim 5, wherein a cover surface layer thickness from a top of the micro lens to a surface of the cover glass is 30 μm or less, and a thickness of the resin layer is 10 μm or less. Lens array substrate.   A liquid crystal panel comprising the microlens array substrate according to claim 1.   A liquid crystal projector comprising the microlens array substrate according to claim 1.   A display device having a microlens array substrate manufactured by the manufacturing method according to claim 1.   A lighting device having a microlens array substrate manufactured by the manufacturing method according to claim 1. A resist layer having a plurality of continuous lens-shaped concave portions and a groove pattern is formed on the surface of a quartz substrate or a glass substrate,
The microlens array substrate, wherein the resist layer is dry-etched, and the lens-shaped concave portion and the groove pattern are transferred to the surface of the quartz substrate or glass substrate to simultaneously form a microlens array and an alignment mark. Manufacturing method. A resist layer having a plurality of continuous lens-shaped concave portions and a groove pattern is formed on the surface of a quartz substrate or a glass substrate,
The resist layer is dry-etched, the lens-shaped recess and the groove pattern are transferred to the surface of the quartz substrate or glass substrate, and a microlens array and an alignment mark are formed simultaneously.
A method of manufacturing a microlens array substrate, wherein a resin having a refractive index different from that of the quartz substrate or the glass substrate is injected into the lens-shaped recess on the surface of the quartz substrate or the glass substrate. A resist layer having a plurality of continuous lens-shaped concave portions and a groove pattern is formed on the surface of a quartz substrate or a glass substrate,
The resist layer is dry-etched, the lens-shaped recess and the groove pattern are transferred to the surface of the quartz substrate or glass substrate, and a microlens array and an alignment mark are formed simultaneously.
Injecting a resin having a refractive index different from that of the quartz substrate or the glass substrate into the lens-shaped recess on the surface of the quartz substrate or the glass substrate, and bonding the cover glass member,
The method for manufacturing a microlens array substrate, wherein the cover glass member is polished to a required thickness. The method for manufacturing a microlens array substrate according to claim 15, wherein a light shielding layer is formed at a position corresponding to a boundary portion between adjacent microlenses on the surface of the cover glass member. A method for producing a microlens array substrate according to claim 16, wherein a transparent protective layer is formed so as to cover the light shielding layer. The thickness of the resin from the top of the microlens to the cover glass member is 10 μm or less, and the cover surface layer thickness from the top of the microlens to the surface of the cover glass is 30 μm or less. The method for producing a microlens array substrate according to any one of claims 15 to 17, wherein the glass member is polished. The method of manufacturing a microlens array substrate according to any one of claims 13 to 18, wherein the plurality of continuous lens-shaped concave portions of the resist layer are formed in a continuous state without a non-lens region.

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