JP2004069790A - Method for manufacturing substrate with recessing part, substrate with recessing part, substrate with recessing part for micro lens, micro lens substrate, counter substrate for liquid crystal panel, liquid crystal panel, and projection display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a substrate with recessing parts, by which desired aspheric recessing parts can easily and certainly be formed by applying a wet etching to the substrate, and to provide the substrate with the recessing parts, the substrate with the recessing parts for micro lenses, a micro lens substrate, a counter substrate for liquid crystal panel, a liquid crystal panel and a projection display device. <P>SOLUTION: The substrate with the recessing parts for the micro lenses is manufactured through a step to form a mask 6 consisting of a control film 61 and a mask film 62 on a surface of a glass substrate 5, a step to form openings 64 on the mask 6, a step to form the recessing parts on the glass substrate 5 with wet etching and a step to remove the mask 6. In this case, the desired aspheric recessing parts are formed with wet etching by suitably adjusting each of conditions of an etching rate of the openings 64 and the control film 61 with respect to an etching liquid, and etching time. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a substrate with a concave portion in which a concave portion is formed on a substrate, a substrate with a concave portion, a substrate with a concave portion for a microlens, a microlens substrate, a counter substrate for a liquid crystal panel, a liquid crystal panel, and a projection display device. is there.
[0002]
[Prior art]
2. Related Art A projection display device that projects an image on a screen is known.
[0003]
In such a projection display device, a liquid crystal panel (liquid crystal optical shutter) is mainly used for image formation.
[0004]
In this liquid crystal panel, for example, a liquid crystal driving substrate (TFT substrate) having a thin film transistor (TFT) for controlling each pixel and a pixel electrode, and an opposing substrate for a liquid crystal panel having a black matrix, a common electrode, and the like form a liquid crystal layer. It is configured to be joined via
[0005]
In a liquid crystal panel (TFT liquid crystal panel) having such a configuration, since a black matrix is formed in a portion other than a portion serving as a pixel of a counter substrate for a liquid crystal panel, an area of light transmitted through the liquid crystal panel is limited. For this reason, the light transmittance decreases.
[0006]
In order to increase the light transmittance, there is known a liquid crystal panel facing substrate provided with a large number of minute microlenses at positions corresponding to respective pixels. Accordingly, light transmitted through the opposite substrate for a liquid crystal panel is focused on the opening formed in the black matrix, and the light transmittance is increased.
[0007]
As a method of forming a concave portion on a substrate in order to form such a microlens, for example, a technique disclosed in JP-A-9-101401 is known.
[0008]
However, in such a technique, a counter substrate for a liquid crystal panel having excellent characteristics, particularly high light transmittance and a high contrast ratio, and furthermore, a liquid crystal panel is appropriately manufactured from a substrate in which a concave portion for forming a microlens is formed. It is difficult.
[0009]
In addition, only a hemispherical lens could be formed by the method using isotropic etching (wet etching). With a lens having a small radius of curvature, such as a microlens, the spherical aberration increases, and the projection transmittance and the projection contrast ratio cannot be obtained sufficiently.
[0010]
[Problems to be solved by the invention]
An object of the present invention is to provide a method of manufacturing a substrate with a concave portion that can easily and surely form a desired aspherical concave portion by performing wet etching on the substrate, a substrate with a concave portion, a substrate with a concave portion for a microlens, and a microlens. It is to provide a substrate, a counter substrate for a liquid crystal panel, a liquid crystal panel, and a projection display device.
[0011]
[Means for Solving the Problems]
Such an object is achieved by the present invention described in the following (1) to (25).
[0012]
(1) A control film having a higher etching rate with respect to an etching solution than a substrate and a mask film are provided on the substrate, and a mask having an opening of a predetermined pattern is placed on the substrate so that the control film is positioned on the substrate side. Forming,
Performing a wet etching using the mask, and forming a concave portion on the substrate, a method for manufacturing a substrate with concave portions,
A substrate having a concave portion, wherein a desired aspheric concave portion is formed by performing wet etching by appropriately adjusting the conditions of the opening, the etching rate of the control film with respect to an etching solution, and the etching time. Manufacturing method.
[0013]
(2) A control film having a higher etching rate with respect to an etching solution than the substrate and a mask film are provided on the substrate, and a mask having an opening of a predetermined pattern is placed on the substrate so that the control film is positioned on the substrate side. Forming,
Forming a hole extending in the thickness direction of the substrate at a position corresponding to the opening of the substrate;
Performing a wet etching using the mask, and forming a concave portion on the substrate, a method for manufacturing a substrate with concave portions,
The desired aspherical concave portion is formed by performing wet etching by appropriately adjusting the conditions of the opening, the hole, the etching rate of the control film with respect to the etchant, and the etching time. Manufacturing method of a substrate with a concave portion.
[0014]
(3) The method of manufacturing a substrate with concave portions according to (2), wherein the adjustment of the hole is an adjustment of the depth of the hole.
[0015]
(4) The method according to (2) or (3), wherein the hole is formed by dry etching.
[0016]
(5) The method for manufacturing a substrate with concave portions according to any one of (1) to (4), wherein the adjustment of the opening is an adjustment of the size of the opening.
[0017]
(6) The substrate with concave portions according to any one of (1) to (4), wherein the shape of the opening in plan view is substantially circular, and the adjustment of the opening is an adjustment of the diameter of the opening. Production method.
[0018]
(7) The method of manufacturing a substrate with concave portions according to any one of (1) to (6), wherein the plurality of concave portions are formed by forming a plurality of the openings.
[0019]
(8) Assuming that the etching rate of the control film with respect to the etching solution is a and the etching rate of the substrate with respect to the etching solution is b, the etching rate ratio a / b is adjusted to 1.01 or more. The method for producing a substrate with concave portions according to any one of (1) to (7).
[0020]
(9) The method according to any one of (1) to (8), wherein the control film is made of silicon oxide.
[0021]
(10) The method according to any one of (1) to (9), wherein the control film is formed by a chemical vapor deposition method.
[0022]
(11) The method according to any one of (1) to (10), wherein the mask film is made of polycrystalline silicon.
[0023]
(12) The method according to any one of (1) to (11), wherein the substrate is a quartz glass substrate.
[0024]
(13) The method according to any one of (1) to (12), wherein the respective conditions are adjusted such that at least a part of the aspheric surface of the formed concave portion includes a paraboloid or a surface similar thereto. A method for manufacturing a substrate with concave portions.
[0025]
(14) The method for manufacturing a substrate with concave portions according to any one of (1) to (13), further comprising a step of removing the mask.
[0026]
(15) The method according to any one of (1) to (14), wherein the recess is a microlens recess.
[0027]
(16) A substrate with concave portions manufactured by the method for manufacturing a substrate with concave portions according to any one of (1) to (15).
[0028]
(17) A substrate with concave portions for microlenses, manufactured by the method for manufacturing a substrate with concave portions according to (15).
[0029]
(18) A microlens substrate manufactured using the substrate with concave portions for microlenses according to (17) and having a plurality of microlenses.
[0030]
(19) The microlens substrate according to (18), wherein the microlens is a biconvex microlens.
[0031]
(20) The first microlens recessed substrate having a plurality of aspheric first microlens recesses described in (17) above, and the second having a plurality of aspheric second microlens recesses. The first microlens concave portion is bonded to the substrate with the microlens concave portion via a resin so that the first microlens concave portion and the second microlens concave portion face each other, thereby forming the first microlens concave portion. A microlens substrate comprising a biconvex microlens formed between a substrate with a concave portion and the second substrate with a concave portion for microlenses.
[0032]
(21) A counter substrate for a liquid crystal panel, comprising the microlens substrate according to any one of (18) to (20).
[0033]
(22) A liquid crystal panel comprising the liquid crystal panel counter substrate according to (21).
[0034]
(23) A liquid crystal driving substrate provided with a pixel electrode, the liquid crystal panel opposing substrate according to (21), which is joined to the liquid crystal driving substrate, and a gap between the liquid crystal driving substrate and the liquid crystal panel opposing substrate. A liquid crystal panel comprising: a sealed liquid crystal.
[0035]
(24) The liquid crystal panel according to the above (23), wherein the liquid crystal drive substrate is a TFT substrate.
[0036]
(25) A projection display device comprising the liquid crystal panel according to any one of (22) to (24).
[0037]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.
[0038]
The substrate with concave portions, the substrate with concave portions for microlenses, and the microlens substrate of the present invention include both an individual substrate and a wafer.
[0039]
In the following description, a case where the substrate with concave portions of the present invention is applied to a substrate with concave portions for a microlens will be described.
[0040]
1 to 8 are schematic longitudinal sectional views showing a method of manufacturing a substrate with concave portions for microlenses when the substrate with concave portions of the present invention is applied to a substrate with concave portions for microlenses. FIG. 10 is a schematic longitudinal sectional view showing a method for manufacturing a counter substrate for a liquid crystal panel, FIG. 10 is a schematic longitudinal sectional view showing a counter substrate for a liquid crystal panel of the present invention, and FIG. FIG. 3 is a schematic plan view showing a substrate.
[0041]
As shown in FIG. 10, the opposing substrate 1 for a liquid crystal panel is bonded to the substrate 2 with concave portions for microlenses and the substrate 2 with concave portions for microlenses via a transparent resin layer 14 having a predetermined refractive index. A cover glass 13, a black matrix 11 formed on the cover glass 13 and having a plurality of (many) openings 111, and a transparent conductive film 12 formed on the cover glass 13 so as to cover the black matrix 11. have. The substrate 2 with concave portions for microlenses is made of a glass substrate 5 having a plurality of (many) aspherical concave portions (recesses for microlenses) 3 formed on the surface. In the resin layer 14, the aspherical microlenses 8 are formed by the resin filled in the concave portions 3 of the substrate 2 with concave portions for microlenses.
[0042]
In the counter substrate 1 for a liquid crystal panel, the black matrix 11 having a light shielding function is provided so as to correspond to the position of the microlens 8. Specifically, the black matrix 11 is provided so that the optical axis Q of the microlens 8 passes through the opening 111 formed in the black matrix 11. Therefore, in the liquid crystal panel opposing substrate 1, the incident light L incident from the surface opposing the black matrix 11 is condensed by the microlenses 8 and passes through the openings 111 of the black matrix 11. The transparent conductive film 12 is a transparent electrode and transmits light. For this reason, when the incident light L passes through the opposite substrate 1 for a liquid crystal panel, a large attenuation of the light amount is prevented. That is, the opposing substrate 1 for a liquid crystal panel has a high light transmittance.
[0043]
In the counter substrate 1 for a liquid crystal panel, one micro lens 8 and one opening 111 of the black matrix 11 correspond to one pixel.
[0044]
The substrate 2 with concave portions for microlenses may have other components such as an antireflection layer.
[0045]
Prior to the description of the method of manufacturing the microlens substrate and the opposing substrate for a liquid crystal panel of the present invention, first, a first embodiment of the method of manufacturing the substrate with concave portions for microlenses (substrate with concave portions) of the present invention will be described. This will be described with reference to FIGS.
[0046]
In the present embodiment, an aspherical lens concave portion (aspherical microlens concave portion) is formed by performing wet etching using a mask including a control film and a mask film and having a predetermined pattern of openings. In particular, by appropriately adjusting the conditions of the opening, the etching rate of the control film with respect to the etching solution, and the etching time, wet etching is performed to obtain a desired (desired shape and size) for an aspherical microlens. A recess is formed. It should be noted that a large number of microlens concave portions are actually formed on the substrate, but here, for ease of explanation, only a part thereof will be illustrated and described.
[0047]
First, in manufacturing the substrate 2 with concave portions for microlenses, a glass substrate 5 is prepared.
[0048]
As the glass substrate 5, a glass substrate having a uniform thickness and having no bending or scratches is preferably used. Further, it is preferable that the surface of the glass substrate 5 is cleaned by washing or the like.
[0049]
Further, when the manufactured substrate 2 with concave portions for microlenses is used for manufacturing a liquid crystal panel, and the liquid crystal panel has a glass substrate other than the glass substrate 5, the thermal expansion coefficient of the glass substrate 5 is determined by the liquid crystal panel. It is preferable that the thermal expansion coefficient of the other glass substrate is substantially equal to that of the other glass substrate. As described above, assuming that the thermal expansion coefficients of the glass substrate 5 and the other glass substrates of the liquid crystal panel are substantially equal, the resulting liquid crystal panel is caused by a difference in thermal expansion coefficient between the two when the temperature changes. Warpage, deflection, etc. are prevented.
[0050]
From such a viewpoint, it is preferable that the glass substrate 5 and another glass substrate included in the liquid crystal panel are formed of the same material. This effectively prevents warpage, deflection, and the like due to differences in thermal expansion coefficients when the temperature changes.
[0051]
In particular, when the manufactured substrate 2 with concave portions for microlenses is used for manufacturing a TFT liquid crystal panel of high-temperature polysilicon, the glass substrate 5 is preferably made of quartz glass. The TFT liquid crystal panel has a TFT substrate as a liquid crystal driving substrate. For such a TFT substrate, quartz glass whose characteristics are hardly changed by the environment at the time of manufacturing is preferably used. Accordingly, by forming the glass substrate 5 from quartz glass in response to this, it is possible to obtain a TFT liquid crystal panel which is less likely to be warped or bent and has excellent stability.
[0052]
Although the thickness of the glass substrate 5 varies depending on various conditions such as a material constituting the glass substrate 5 and a refractive index, it is usually preferably about 0.3 to 3 mm, more preferably about 0.5 to 2 mm. When the thickness is within this range, a compact substrate 2 with concave portions for microlenses having necessary optical characteristics can be obtained.
[0053]
<1> First, as shown in FIG. 1A, a control film (control layer) 61 is formed on the glass substrate 5, and a mask film (mask layer) 62 is formed on the control film 61. At the same time, a back surface protective layer 69 is formed on the back surface of the glass substrate 5 (the surface opposite to the surface on which the control film 61 and the mask film 62 are formed). Of course, the mask film 62 and the back surface protective layer 69 can also be formed simultaneously by using, for example, a CVD method or the like.
[0054]
The control film 61 and the mask film 62 constitute the mask 6, and the control film 61 and the mask film 62 form an etching rate (hereinafter simply referred to as “etching rate”) for an etching solution used in wet etching in a step <3> described later. ) (Etching speed) is different, and the etching rate of the mask film 62 is smaller than the etching rate of the control film 61.
[0055]
That is, the mask film 62 is a portion that functions as a mask, and preferably has resistance to wet etching in the step <3> described later. In other words, it is preferable that the mask film 62 be configured so that the etching rate is substantially equal to or lower than that of the glass substrate 5.
[0056]
From this viewpoint, as a material forming the mask film 62, for example, a metal such as polycrystalline silicon (polysilicon), amorphous silicon, Au / Cr, Au / Ti, Pt / Cr, Pt / Ti, SiC, Silicon nitride and the like can be given.
[0057]
Among them, polycrystalline silicon is particularly preferable as a material forming the mask film 62. When the mask film 62 is made of polycrystalline silicon, a dense layer can be formed on the surface of the control film 61. Therefore, defects such as pinholes are less likely to occur in the mask film 62. Thereby, when the concave portion (recess for microlens) 3 is formed by performing wet etching on the glass substrate 5 in the step <3> described later, the etchant hardly enters unnecessary portions, which is ideal. It is possible to form the concave portions 3 corresponding to various lens shapes. Therefore, by forming the mask film 62 of polycrystalline silicon, it is possible to obtain a high-performance substrate 2 with concave portions for microlenses with a high yield.
[0058]
Although the thickness of the mask film 62 varies depending on the material constituting the mask film 62, when the mask film 62 is made of polycrystalline silicon, the thickness is preferably about 0.01 to 10 μm, and 0.2 to 1 μm. The degree is more preferred. If the thickness is less than the lower limit of this range, the masked portion of the glass substrate 5 may not be sufficiently protected when performing wet etching in the step <3> described below. The mask film 62 may be easily peeled off due to the internal stress of the film 62.
[0059]
When the mask film 62 is made of polycrystalline silicon, for example, the mask film 62 can be suitably formed by a chemical vapor deposition method (CVD method). This is because, according to the chemical vapor deposition method, monosilane gas (SiH ₄ ) Is allowed to react on the surface of the control film 61 to form a polycrystalline silicon film, so that defects such as pinholes, which are likely to occur when the film is formed by a sputtering method or the like, are effectively reduced. And a dense and adherent film can be formed.
[0060]
When the mask film 62 made of polycrystalline silicon is formed by the CVD method, the temperature at the time of forming the mask film 62 is not particularly limited, but is preferably about 300 to 800 ° C, and more preferably about 400 to 700 ° C. Further, the pressure at the time of forming the mask film 62 is not particularly limited, but is preferably about 30 to 160 Pa, and more preferably about 50 to 100 Pa. In addition, SiH ₄ The supply rate of the gas serving as a raw material for forming polycrystalline silicon is not particularly limited, but is preferably about 10 to 500 mL / min, and more preferably about 40 to 400 mL / min. When the conditions for forming the polycrystalline silicon layer are within such a range, the mask film 62 can be suitably formed.
[0061]
On the other hand, the control film 61 is configured so that the etching rate is higher than that of the glass substrate 5.
[0062]
As a result, the degree of etching of the glass substrate 5 when wet etching is performed on the glass substrate 5 in the step <3> described later varies depending on the position and the direction. That is, when the degree of etching in the thickness direction (vertical direction in the figure) of the glass substrate 5 is A, and the degree of etching in the direction perpendicular to the thickness direction (side direction) is B, As B becomes larger than A, the ratio B / A becomes larger toward the front side (upper side in the figure) of the glass substrate 5, whereby the aspherical concave portion 3 is formed on the glass substrate 5. You.
[0063]
Assuming that the etching rate of the control film 61 is a and the etching rate of the glass substrate 5 is b, the etching rate ratio a / b is appropriately set according to the target shape of the concave portion 3 to be formed. It is preferably 1.01 or more, more preferably about 1.05 to 2.0. Thereby, the concave portion 3 can be formed on the glass substrate 5 with higher accuracy.
[0064]
It should be noted that as the etching rate a of the control film 61 is larger, that is, as the ratio a / b of this etching rate is larger, the rate of change of the glass substrate 5 of B or B / A in the vertical direction in the figure (in the figure, The rate of increase toward the upper side) is large.
[0065]
Examples of a material constituting the control film 61 include metals such as Au, Pt, Cr, and Ti; metal film laminates such as Au / Cr, Au / Ti, Pt / Cr, and Pt / Ti; ₂ Silicon oxide (SiO _X ), Various resist materials, polyimide, acrylic resin, epoxy resin and the like. Among these, silicon oxide (SiO 2) _X Is preferred. And, in particular, SiO ₂ Sputtered film, SiO ₂ CVD film, SiO ₂ A TEOS film or the like is preferable.
[0066]
The thickness of the control film 61 varies depending on the material constituting the control film 61 and the target shape of the concave portion 3 to be formed, but when the control film 61 is formed of silicon oxide, the thickness is about 50 ° to 1 μm. Is preferably, and more preferably about 100 to 0.1 μm. If the thickness is less than the lower limit of this range, the etching rate may become unstable when performing wet etching in the step <3> described below. If the thickness exceeds the upper limit, only the control film 61 is etched. Unnecessary time required to perform the operation increases.
[0067]
When the control film 61 is made of silicon oxide, for example, the control film 61 can be suitably formed by a chemical vapor deposition method (CVD method). This is because, according to the chemical vapor deposition method, SiH ₄ Can react on the surface of the glass substrate 5 to form a silicon oxide film, so that defects such as pinholes, which are likely to occur when the film is formed by a sputtering method or the like, are effectively suppressed. And a dense and adherent film can be formed.
[0068]
Here, in the present embodiment, the conditions of the etching rate of the control film 61, the opening 64 of the mask 6 described later, and the etching time are appropriately adjusted (set), and wet etching is performed in a step <3> described later. As a result, a desired aspherical concave portion 3 is formed.
[0069]
In this case, it is preferable to adjust each of the conditions so that at least a part of the aspheric surface of the formed concave portion 3 includes a predetermined paraboloid or a surface similar thereto, and all of the aspheric surfaces are It is more preferable to adjust each of the above conditions so as to obtain a predetermined paraboloid or a surface similar thereto. Thereby, an aspherical concave portion 3 suitable for an aspherical lens is formed.
[0070]
The etching rate of the control film 61 is determined, for example, by the constituent material, thickness, density, porosity, forming method and forming conditions (for example, temperature) of the control film 61, presence or absence of heat treatment after film formation, and heat treatment conditions (for example, , Temperature, time, etc.) are adjusted to a predetermined value by setting necessary one or more conditions.
[0071]
Note that the back surface protection layer 69 is for protecting the back surface of the glass substrate 5 in the subsequent steps. The back surface protective layer 69 suitably prevents erosion, deterioration, and the like of the back surface of the glass substrate 5. The back surface protective layer 69 is made of, for example, the same material as the mask film 62. For this reason, the back surface protective layer 69 can be provided at the same time as the formation of the mask film 62, similarly to the mask film 62.
[0072]
<2> Next, as shown in FIG. 1B, an opening 64 is formed in the mask 6 including the control film 61 and the mask film 62. The opening 64 is formed, for example, by applying a resist (for example, a photoresist or the like) corresponding to the opening 64 on the mask 6, further applying a second mask 63 on the mask 6, and then applying the second mask 63. Is performed by removing the portion of the mask 6 which is not masked by the step (2), and then removing the second mask 63.
[0073]
The mask 6 may be removed when the mask film 62 is made of polycrystalline silicon or when the control film 61 is made of silicon oxide, for example, by dry etching with CF gas, chlorine-based gas, etc. + It can be performed by immersion (wet etching) in a stripping solution such as a nitric acid aqueous solution or an alkaline aqueous solution.
[0074]
Here, as described above, in the present embodiment, the condition (for example, size) of the opening 64 of the mask 6 is appropriately adjusted according to the target shape of the concave portion 3 to be formed.
[0075]
In this case, in the illustrated example, the shape of the opening 64 in a plan view is circular, and the diameter of the opening 64 is adjusted. The diameter of the opening 64 is preferably adjusted to about 0.2 to 5 μm. , And more preferably about 0.5 to 1 μm.
[0076]
It goes without saying that the shape of the opening 64 is not limited to a circle.
[0077]
<3> Next, as shown in FIGS. 2C and 2D, wet etching is performed on the glass substrate 5 using the mask 6 to form a large number of aspherical concave portions 3 on the glass substrate 5.
[0078]
At this time, as shown in FIG. 2C, the glass substrate 5 is etched from the portion where the mask 6 does not exist, that is, from the opening 64, and simultaneously (at the same time), the control film 61 is also etched from the opening 64. .
[0079]
As described above, since the etching rate of the control film 61 is higher than the etching rate of the glass substrate 5, the control film 61 precedes the glass substrate 5 near the surface (upper side in the figure) of the glass substrate 5. Then, the glass substrate 5 is etched at substantially the same etching rate as that of the control film 61.
[0080]
Therefore, the ratio B of the degree A of etching in the thickness direction (vertical direction in the figure) of the glass substrate 5 to the degree B of etching in the direction perpendicular to the thickness direction (side direction) B / A increases toward the front surface side (upper side in the figure) of the glass substrate 5, whereby the aspherical concave portions 3 are formed in the portions of the glass substrate 5 where the openings 64 are provided. The radius of curvature of the recess 3 gradually increases from near the center toward the peripheral edge.
[0081]
Here, as described above, in the present embodiment, the time (etching time) for performing this wet etching together with the etching rate of the control film 61 and the opening 64 of the mask 6 is appropriately determined according to the target shape of the concave portion 3 to be formed. adjust. Thereby, a desired aspherical concave portion 3 is formed on the glass substrate 5.
[0082]
When the wet etching method is used, the concave portion 3 can be suitably formed. When an etching solution containing hydrofluoric acid (a hydrofluoric acid-based etching solution) is used as the etching solution, the glass substrate 5 can be selectively etched, and the concave portion 3 can be suitably formed.
[0083]
Further, according to wet etching, processing can be performed with a simpler apparatus than in dry etching, and further, processing can be performed on many substrates at once. Thereby, productivity is improved and the substrate 2 with concave portions for microlenses can be provided at low cost.
[0084]
<4> Next, as shown in FIG. 3E, the mask 6 is removed. At this time, the back surface protective layer 69 is also removed together with the removal of the mask 6.
[0085]
When the mask film 62 or the like is made of polycrystalline silicon or when the control film 61 is made of silicon oxide, for example, dry etching with CF gas, chlorine-based gas, etc., hydrofluoric acid + nitric acid aqueous solution, alkali aqueous solution, etc. Can be carried out by immersion (wet etching) in a stripper.
[0086]
Although description is omitted, it is preferable to provide an alignment mark 4 as an index when positioning on the glass substrate 5 as shown in FIG. An opening 44 is formed in the alignment mark 4 in the illustrated example.
[0087]
As described above, as shown in FIG. 3E, the substrate 2 with concave portions for microlenses in which a large number of aspheric concave portions 3 are formed on the glass substrate 5 is obtained.
[0088]
As described above, the conditions such as the etching rate of the opening 64 of the mask 6, the etching rate of the control film 61, and the etching time are appropriately adjusted, and the wet etching is performed using the mask 6, so that the desired etching is performed on the glass substrate 5. The aspherical concave portion 3 can be formed, and the substrate 2 with concave portion for microlenses having the aspherical concave portion 3 suitable for an aspheric lens can be manufactured.
[0089]
That is, since the substrate 2 with concave portions for microlenses has the concave portion 3 of aspherical surface suitable for an aspherical lens, the aspherical lens formed using the substrate 2 with concave portions for microlenses has a spherical surface. Aberration is suppressed. The microlens substrate and the counter substrate for a liquid crystal panel using the substrate with concave portions for microlenses of the present embodiment have high light use efficiency, high contrast ratio, and excellent optical characteristics.
[0090]
In the above description, the glass substrate 5 is used as the substrate of the substrate 2 with concave portions for microlenses. However, in the present invention, the constituent material of the substrate is not limited to glass. It may be.
[0091]
The alignment mark 4 (see FIG. 11) formed on the substrate 2 with concave portions for microlenses is used as an index for positioning when the counter substrate 1 for liquid crystal panel is manufactured.
[0092]
The formation position of the alignment mark 4 is not particularly limited. For example, as shown in FIG. 11, the alignment mark 4 can be formed outside the region where the concave portion 3 is formed.
[0093]
The alignment marks 4 are preferably provided at a plurality of locations on the substrate 2 with concave portions for microlenses. In particular, it is preferable that a plurality of alignment marks 4 are provided at the corners of the substrate 2 with concave portions for microlenses. Thereby, positioning can be performed more easily.
[0094]
FIG. 11 shows an example in which the alignment mark 4 has a cross shape. The shape of the alignment mark 4 is not particularly limited, but preferably has a corner portion 41 forming a corner as shown in FIG. When the alignment mark 4 has the corners 41 as described above, positioning can be performed more accurately.
[0095]
Furthermore, as shown in FIG. 11, it is preferable that the alignment mark 4 has a mark (a circular opening 44 in FIG. 11) indicating the central portion thereof. Thereby, the positioning accuracy can be further improved.
[0096]
The configuration (structure) and forming method of the alignment mark 4 are not particularly limited. For example, as shown in FIG. 3E and FIG. 11, by forming a layer on the glass substrate 5, the alignment mark can be formed. A recess having a shape different from that of the recess 3 may be provided as an alignment mark on the glass substrate 5.
[0097]
The alignment mark 4 can be used for various positioning when assembling various types using the substrate 2 with concave portions for microlenses. For example, when manufacturing the liquid crystal panel counter substrate 1 having the black matrix 11 using the substrate 2 with concave portions for microlenses, the black matrix 11 is formed with the concave portions 3, that is, the microlenses 8 using the alignment mark 4 as an index. It can be positioned at a corresponding position.
[0098]
Next, a second embodiment of the method for manufacturing a substrate with concave portions for microlenses (substrate with concave portions) of the present invention will be described with reference to FIG.
[0099]
In the following description, differences from the above-described first embodiment will be mainly described, and description of similar items will be omitted.
[0100]
In the present embodiment, similarly to the first embodiment described above, the wet etching is performed by appropriately adjusting the conditions of the opening 64 of the mask 6, the etching rate of the control film 61, and the etching time. Although the aspherical concave portion 3 is formed, the pattern of the control film 61 is different from that of the first embodiment.
[0101]
That is, in the present embodiment, the control film 61 is formed in an annular shape on the glass substrate 5 as shown in FIG. Hereinafter, this will be described in more detail.
[0102]
<1A> First, as shown in FIG. 4 (f), a control film 61 composed of a plurality of annular unit films 611 having different diameters is concentrically (concentrically) formed on a glass substrate 5 at a predetermined interval. The mask film 62 is formed on the control film 61 (on each unit film 611) and on the glass substrate 5 between the adjacent unit films 611. At the same time, a back surface protective layer 69 is formed on the back surface of the glass substrate 5 (the surface opposite to the surface on which the control film 61 and the mask film 62 are formed).
[0103]
Here, in the present embodiment, in addition to the conditions of the opening 64 of the mask 6, the etching rate of the control film 61, and the etching time, for example, the number of the unit films 611, the width of the unit films 611, the adjacent unit films One or more necessary conditions, such as the interval between 611, are appropriately adjusted (set), and wet etching is performed in a later step to form a desired aspherical concave portion 3.
[0104]
Subsequent steps are the same as steps <2> to <4> of the above-described first embodiment, and detailed description thereof will be omitted. However, in the present embodiment, the mask 6 is used to attach the glass substrate 5 to the glass substrate 5. When wet etching is performed, the glass substrate 5 and the unit film 611 on the inner peripheral side in the figure are etched from the opening 64, respectively, and after the unit film 611 on the inner peripheral side is entirely etched, the etching of the glass substrate 5 is performed. When the notch, which is not shown, becomes larger and reaches the outer peripheral unit film 611 in the drawing, the etching liquid comes into contact with the outer peripheral unit film 611, and the outer peripheral unit film 611 is etched. Engraved. Thereafter, the same operation is repeated, and the aspheric concave portion 3 is formed on the glass substrate 5.
[0105]
According to the second embodiment, the same effects as those of the first embodiment can be obtained. It goes without saying that the pattern of the control film 61 is not limited to the illustrated example.
[0106]
Next, a third embodiment of the method of manufacturing a substrate with concave portions for microlenses (substrate with concave portions) of the present invention will be described with reference to FIGS.
[0107]
In the following description, differences from the above-described first embodiment will be mainly described, and description of similar items will be omitted.
[0108]
In the present embodiment, in addition to the steps of the first embodiment described above, a bottomed hole 55 extending in the thickness direction of the glass substrate 5 is further formed at a position corresponding to the opening 64 of the glass substrate 5. The wet etching is performed by appropriately adjusting the conditions of the etching rate and the etching time of the opening 64, the hole 55, and the control film 61 of the mask 6 to obtain a desired aspherical surface. Is formed. Hereinafter, this will be described in more detail.
[0109]
<1B> First, as shown in FIG. 5G, a control film 61 is formed on the glass substrate 5, and a mask film 62 is formed on the control film 61. At the same time, a back surface protective layer 69 is formed on the back surface of the glass substrate 5 (the surface opposite to the surface on which the control film 61 and the mask film 62 are formed).
[0110]
<2B-1> Next, as shown in FIG. 5H, an opening 64 is formed in the mask 6 composed of the control film 61 and the mask film 62. The opening 64 is formed, for example, by applying a resist (for example, a photoresist or the like) corresponding to the opening 64 on the mask 6, further applying a second mask 63 on the mask 6, and then applying the second mask 63. Is performed by removing the portion of the mask 6 which is not masked by the step (2), and then removing the second mask 63.
[0111]
Note that the process may proceed to a step <3B> to be described later with the second mask 63 remaining. In this case, in a step <3B> described later, a third mask 65 and the second mask 63 described later are removed.
[0112]
Here, as described above, in the present embodiment, the condition (for example, size) of the opening 64 of the mask 6 is appropriately adjusted according to the target shape of the concave portion 3 to be formed.
[0113]
In this case, in the illustrated example, the shape of the opening 64 in a plan view is circular, and the diameter of the opening 64 is adjusted. The diameter of the opening 64 is preferably about 2 to 15 μm, and preferably 3 to 7 μm. More preferably, it is about
It goes without saying that the shape of the opening 64 is not limited to a circle.
[0114]
<2B-2> Next, as shown in FIG. 6 (i), the glass substrate 5 extends in the thickness direction of the glass substrate 5 at a position corresponding to the opening 64 (the center of the opening 64 in the illustrated example). An existing bottomed hole 55 is formed. The holes 55 are formed, for example, by applying a resist (for example, a photoresist or the like) corresponding to the holes 55 on the mask 6 and the glass substrate 5 and further forming a third mask 65 on the mask 6 and the glass substrate 5. Then, the glass substrate 5 in a portion not masked by the third mask 65 is removed, and then the third mask 65 is removed.
[0115]
Note that various methods can be used to remove the glass substrate 5, but the glass substrate 5 can be removed by, for example, CHF. ₃ It is preferable to perform dry etching using a system gas or the like.
[0116]
Here, in the present embodiment, in addition to the conditions of the opening 64 of the mask 6, the etching rate of the control film 61, and the etching time, the condition of the hole 55 is appropriately adjusted (set), and a process described below is performed. The desired aspherical concave portion 3 is formed by performing wet etching in the step <1>.
[0117]
In this case, as a condition of the hole 55, in the present embodiment, the depth of the hole 55 (length in the vertical direction in the figure) is adjusted, but the depth of the hole 55 is adjusted to 10 μm or less. Preferably, the thickness is adjusted to about 1 to 5 μm.
[0118]
By adjusting the depth of the hole 55, the depth of the concave portion 3 (the maximum thickness of the lens) can be adjusted.
[0119]
In the illustrated example, the shape of the hole 55 in a plan view is a circle. The diameter of the hole 55 is not particularly limited, but is preferably about 0.2 to 5 μm, and more preferably about 0.5 to 1 μm.
Needless to say, the shape of the hole 55 is not limited to a circle.
[0120]
<3B> Next, as shown in FIGS. 6 (j), 7 (k) and (l), the glass substrate 5 is wet-etched using the mask 6 to form a large number of aspherical surfaces on the glass substrate 5. The recess 3 is formed.
[0121]
The operation at this time is substantially the same as that of the above-described first embodiment, and a detailed description thereof will be omitted. However, as shown in FIGS. 6 (j), 7 (k) and (l), the opening 64 The glass substrate 5 and the control film 61 are further etched, whereby the aspheric concave portions 3 are formed in the portions of the glass substrate 5 where the openings 64 are provided.
[0122]
<4B> Next, as shown in FIG. 8N, the mask 6 is removed. At this time, the back surface protective layer 69 is also removed together with the removal of the mask 6.
[0123]
As described above, as shown in FIG. 8 (n), the substrate 2 with concave portions for microlenses in which many aspheric concave portions 3 are formed on the glass substrate 5 is obtained.
[0124]
According to the third embodiment, the same effects as those of the first embodiment can be obtained. In the third embodiment, in addition to the conditions adjusted in the first embodiment described above, the depth of the hole 55 is further adjusted to perform wet etching. The degree increases.
[0125]
In the third embodiment, the control film 61 may be formed in an annular shape on the glass substrate 5 as in the above-described second embodiment.
[0126]
Hereinafter, a method for manufacturing the microlens substrate and the opposing substrate 1 for a liquid crystal panel using the substrate 2 with concave portions for microlenses will be described with reference to FIG.
[0127]
The substrate with concave portions for microlenses and the microlens substrate of the present invention may be, for example, various electro-optical devices such as CCDs and optical communication devices, and other devices, in addition to the opposing substrates and liquid crystal panels for liquid crystal panels described below. Needless to say, it can be used for
[0128]
<5> First, as shown in FIG. 9 (o), the cover glass 13 is bonded to the surface of the substrate 2 with concave portions for microlenses, on which the concave portions 3 are formed, via an adhesive.
[0129]
By curing (solidifying) the adhesive, a resin layer (adhesive layer) 14 is formed. Thus, the microlenses 8 which are formed of the resin filled in the concave portions 3 and function as convex lenses are formed in the resin layer 14.
[0130]
Note that an optical adhesive having a higher refractive index (for example, about n = 1.60) than the refractive index of the glass substrate 5 is suitably used as the adhesive.
[0131]
<6> Next, as shown in FIG. 9 (p), the thickness of the cover glass 13 is reduced.
[0132]
This can be performed by, for example, grinding, polishing, etching, or the like the cover glass 13.
[0133]
The thickness of the cover glass 13 is preferably about 10 to 1000 μm, more preferably about 20 to 150 μm, from the viewpoint of obtaining the opposing substrate 1 for a liquid crystal panel having necessary optical characteristics.
[0134]
If the laminated cover glass 13 has an optimum thickness for performing the subsequent steps, this step need not be performed.
[0135]
<7> Next, as shown in FIG. 9 (q), the black matrix 11 having the openings 111 formed thereon is formed on the cover glass 13.
[0136]
At this time, the black matrix 11 is formed so as to correspond to the position of the microlens 8, specifically, so that the optical axis Q of the microlens 8 passes through the opening 111 of the black matrix 11 (see FIG. 10).
[0137]
The black matrix 11 is composed of, for example, a metal film of Cr, Al, Al alloy, Ni, Zn, Ti, or the like, a resin layer in which carbon, titanium, or the like is dispersed. Among them, the black matrix 11 is preferably made of a Cr film or an Al alloy film. When the black matrix 11 is composed of a Cr film, the black matrix 11 having excellent light shielding properties can be obtained. When the black matrix 11 is made of an Al alloy film, the counter substrate 1 for a liquid crystal panel having excellent heat dissipation can be obtained.
[0138]
The thickness of the black matrix 11 is preferably about 0.03 to 1.0 μm, more preferably about 0.05 to 0.3 μm, from the viewpoint of suppressing the influence on the flatness of the counter substrate 1 for a liquid crystal panel.
[0139]
The black matrix 11 in which the openings 111 are formed can be formed, for example, as follows. First, a thin film to be the black matrix 11 is formed on the cover glass 13 by a vapor deposition method such as sputtering. Next, a resist film is formed on the thin film serving as the black matrix 11. Next, using the alignment mark 4 as an index, the resist film is exposed so that the opening 111 of the black matrix 11 comes to a position corresponding to the microlens 8 (the concave portion 3), and a pattern of the opening 111 is formed in the resist film. I do. Next, wet etching is performed to remove only the portion of the thin film that will become the opening 111. Next, the resist film is removed. In addition, as the stripping solution for performing the wet etching, for example, when the thin film to be the black matrix 11 is made of an Al alloy or the like, a phosphoric acid-based etching solution can be used.
[0140]
Note that the black matrix 11 in which the openings 111 are formed can also be suitably formed by dry etching using a chlorine-based gas or the like.
[0141]
<8> Next, a transparent conductive film (common electrode) 12 is formed on the cover glass 13 so as to cover the black matrix 11.
[0142]
Thereby, the opposing substrate 1 for a liquid crystal panel, or a wafer capable of taking a plurality of opposing substrates 1 for a liquid crystal panel can be obtained.
[0143]
This transparent conductive film 12 is made of, for example, indium tin oxide (ITO), indium oxide (IO), tin oxide (SnO). ₂ ).
[0144]
The thickness of the transparent conductive film 12 is preferably about 0.03 to 1 μm, and more preferably about 0.05 to 0.30 μm.
[0145]
This transparent conductive film 12 can be formed, for example, by sputtering.
[0146]
<9> Finally, the wafer of the opposing substrate 1 for a liquid crystal panel is cut into a predetermined shape and size using a dicing apparatus or the like (for example, as indicated by a dashed line in FIG. 11).
[0147]
Thereby, the counter substrate 1 for a liquid crystal panel as shown in FIG. 10 can be obtained. Since the micro lens 8 included in the liquid crystal panel facing substrate 1 is an aspheric lens, the spherical aberration is suppressed and the optical lens has excellent optical characteristics.
[0148]
This step may not be performed when cutting is not necessary, such as when the opposing substrate 1 for a liquid crystal panel is obtained in the step <8>.
[0149]
In the above-described embodiment, the alignment mark 4 is formed outside the region where the concave portion 3 is formed on the substrate 2 with concave portions for microlenses. However, the alignment mark 4 may be formed inside the region where the concave portion 3 is formed. Needless to say.
[0150]
In the case of manufacturing a counter substrate for a liquid crystal panel, for example, the transparent conductive film 12 may be formed directly on the cover glass 13 without forming the black matrix 11.
[0151]
In the above-described embodiment, the alignment mark 4 is used for positioning the black matrix 11. However, when the opposing substrate 1 for a liquid crystal panel or its wafer has other components, the alignment mark 4 is used for positioning the black matrix 11. May be used.
[0152]
Further, the alignment mark 4 may be used for positioning other than the constituent elements of the counter substrate 1 for a liquid crystal panel, for example, another substrate such as a TFT substrate (liquid crystal driving substrate).
[0153]
In the description of the method of manufacturing the opposing substrate 1 for a liquid crystal panel, a case where the resin 3 is filled in the concave portion 3 of the substrate 2 with concave portions for microlenses, sandwiched by the cover glass 13, and the microlenses 8 are formed of the resin. As described in the example, the microlens substrate can also be manufactured by a 2P method (photopolymerization) using the substrate 2 with concave portions for microlenses as a mold.
[0154]
Hereinafter, a method for manufacturing a microlens substrate by the 2P method will be described with reference to FIGS.
[0155]
First, as shown in FIG. 12A, a substrate 2 with concave portions for microlenses having concave portions 3 for microlenses formed according to the present invention is prepared. In this method, the substrate 2 with concave portions for microlenses in which the concave portions 3 are formed is used as a mold. The microlenses 8 are formed by filling the recesses 3 with resin. Note that, for example, a release agent or the like may be applied to the inner surface of the concave portion 3. Then, the substrate 2 with concave portions for microlenses is set, for example, so that the concave portions 3 open vertically upward.
[0156]
<C1> Next, an uncured resin constituting the resin layer 141 (microlens 8) is supplied onto the substrate 2 with concave portions for microlenses in which the concave portions 3 are formed.
<C2> Next, the transparent substrate 51 is bonded to the resin and pressed and adhered.
[0157]
<C3> Next, the resin is cured. This curing method is appropriately selected depending on the type of the resin, and examples thereof include ultraviolet irradiation, heating, and electron beam irradiation.
[0158]
Thereby, as shown in FIG. 12B, the resin layer 141 is formed, and the microlens 8 is formed by the resin filled in the recess 3.
[0159]
<C4> Next, as shown in FIG. 12C, the substrate 2 with concave portions for microlenses, which is a mold, is removed from the microlenses 8.
[0160]
<C5> Next, as shown in FIG. 13, for example, after setting the transparent substrate 51 so that the microlenses 8 face vertically upward, the uncured resin that forms the resin layer 142 is removed from the microlenses 8. Supply on top. Examples of the supply method include a coating method such as spin coating, and a 2P method using a flat plate mold or the like.
[0161]
<C6> Next, as shown in FIG. 14, the glass substrate (glass layer) 52 is bonded to the resin, pressed and adhered, and then the resin is cured to form the resin layer 142.
[0162]
<C7> Thereafter, if necessary, the thickness of the glass substrate 52 may be adjusted by grinding, polishing, or the like.
Thus, a microlens substrate as shown in FIG. 14 is obtained.
[0163]
Thereafter, a black matrix, a transparent conductive film, and the like are formed on the glass substrate 52 in the same manner as described above, whereby a counter substrate for a liquid crystal panel can be obtained.
[0164]
In the above description, a microlens substrate provided with a plano-convex lens (plano-convex microlens) constituted by using one substrate with a microlens concave portion is used. However, the present invention is not limited to this.
[0165]
Hereinafter, a microlens substrate provided with a biconvex lens (biconvex microlens) configured using two substrates with concave portions for microlenses will be described.
[0166]
FIG. 15 is a schematic longitudinal sectional view showing an embodiment of the microlens substrate.
[0167]
As shown in the figure, the microlens substrate includes a first microlens recessed substrate (first substrate) 21 and a second microlens recessed substrate (second substrate) manufactured according to the present invention. ), A resin layer 14, microlenses 8, and spacers 9.
[0168]
The first substrate 21 with concave portions for microlenses has a plurality of (many) first concave portions (microlenses) having an aspheric concave curved surface (lens curved surface) on a first glass substrate (first transparent substrate) 53. (Recess recess) 36 and a first alignment mark 42 are formed.
[0169]
The second substrate with microlens concave portions 22 has a plurality of (many) second concave portions (microlenses) having an aspheric concave curved surface (lens curved surface) on a second glass substrate (second transparent substrate) 54. (Recess recess) 37 and a second alignment mark 43 are formed.
[0170]
The microlens substrate is configured such that the first substrate 21 with concave portions for microlenses and the second substrate 22 with concave portions for microlenses face the first concave portion 36 and the second concave portion 37. It is configured to be joined via a resin layer (adhesive layer) 14. In this microlens substrate, the space between the first concave portion 36 and the second concave portion 37 is filled between the first microlens recessed substrate 21 and the second microlens recessed substrate 22. A microlens 8 composed of an aspherical biconvex lens is constituted by the resin thus obtained.
[0171]
This microlens substrate has two regions, an effective lens region 99 and a non-effective lens region 100. The effective lens region 99 is a region where the microlens 8 formed of the resin filled in the first concave portion 36 and the second concave portion 37 is effectively used as a microlens when used. On the other hand, the non-effective lens area 100 refers to an area other than the effective lens area 99.
[0172]
Such a microlens substrate is used, for example, by allowing light L to enter from the first microlens recessed substrate 21 side and emitting light L from the second microlens recessed substrate 22 side. .
[0173]
When the microlens 8 is formed of a biconvex lens like this microlens substrate, the aberration (particularly, spherical aberration) of the microlens 8 is further reduced. For this reason, the incident light L that has entered not only near the center of the microlens 8 but also near the edge of the microlens 8 is suitably collected by the microlens 8. That is, the light use efficiency of the micro lens 8 is high. Therefore, this microlens substrate can emit outgoing light L having high luminance.
[0174]
In addition, when the aberration of the microlens 8 is reduced, it is possible to appropriately prevent the outgoing light from being emitted in a direction largely shifted from the optical axis of the microlens 8. Therefore, when the microlens substrate is used for a liquid crystal panel, it is possible to appropriately prevent the outgoing light passing through the microlens 8 from entering adjacent pixels. That is, crosstalk between pixels is prevented. Therefore, when an image is formed using a liquid crystal panel provided with this microlens substrate, the luminance of black becomes extremely low.
[0175]
Since the microlens substrate having the above-described configuration has such advantages, when an image is formed using a liquid crystal panel including the microlens substrate, black is darker and white is brighter. Therefore, in a liquid crystal panel including a microlens substrate, a high contrast ratio can be obtained, and a more beautiful image can be formed.
[0176]
Then, such a microlens substrate can be manufactured, for example, as follows. Hereinafter, a method for manufacturing a microlens substrate will be described with reference to FIGS.
[0177]
When manufacturing the microlens substrate, first, the first substrate 21 with concave portions for microlenses and the second substrate 22 with concave portions for microlenses manufactured according to the present invention are prepared.
[0178]
In this case, the aspherical shape (for example, the radius of curvature) of the first concave portion 36 of the first microlens concave portion substrate 21 and the aspherical surface of the second concave portion 37 of the second microlens concave portion substrate 22. The shape may be different. By making the aspherical shape of the first concave portion 36 and the aspherical shape of the second concave portion 37 different, aberration can be effectively reduced.
[0179]
<D1> First, as shown in FIG. 16, a predetermined refractive index (not shown) is formed on the surface of the first substrate 21 with concave portions for microlenses where the first concave portions 36 are formed so as to cover at least the effective lens region 99. In particular, an uncured resin 143 having a refractive index higher than the refractive indexes of the first glass substrate 53 and the second glass substrate 54 is supplied, and the first concave portion 36 is filled with the resin 143. At this time, the uncured resin 144 including the spacer 9 is supplied onto the first substrate 21 with concave portions for microlenses. The resin 144 is supplied to, for example, a portion where the spacer 9 is installed.
[0180]
The resin 143 and the resin 144 are preferably made of the same type of material. Accordingly, in the microlens substrate to be manufactured, warpage, deflection, and the like due to the difference in the thermal expansion coefficient between the resin 143 and the resin 144 are preferably prevented.
[0181]
When the resin 143 is supplied onto the first substrate 21 with concave portions for microlenses, if the spacers 9 are dispersed in the resin 144, it is easy to uniformly dispose the spacers 9. Thereby, thickness unevenness of the formed resin layer 14 is suitably suppressed.
[0182]
<D2> Next, as shown in FIG. 16, a second substrate with a concave portion for microlenses (counterpart) 22 is set on the resin 143 and the resin 144 (the second substrate with a concave portion for microlens 22 is made of resin. Adhere to).
[0183]
At this time, the second concave substrate 22 with microlenses is placed on the resin such that the first concave portion 36 and the second concave portion 37 face each other. At this time, the second substrate 22 with microlens concave portions is placed on the resin so that the second substrate 22 with microlens concave portions abuts on the spacer 9. Thus, the distance between the opposing end faces of the first substrate 21 with concave portions for microlenses and the second substrate 22 with concave portions for microlenses is defined by the spacer 9. Therefore, the edge thickness and the maximum thickness of the micro lens 8 are defined with high accuracy.
[0184]
<D3> Next, the first concave portion 36 and the second concave portion 37 are aligned using the first alignment mark 42 and the second alignment mark 43. Thereby, the second recess 37 can be accurately positioned at a position corresponding to the first recess 36. For this reason, the shape and optical characteristics of the formed micro lens 8 become closer to the design values.
[0185]
<D4> Next, the resin 143 and the resin 144 are cured to form the resin layer 14.
[0186]
Thereby, the second substrate 22 with concave portions for microlenses is joined to the first substrate 21 with concave portions for microlenses via the resin layer 14. The micro lens 8 is formed of the resin that fills the space between the first concave portion 36 and the second concave portion 37 among the resins that make up the resin layer 14. The curing of the resin can be performed, for example, by irradiating the resin with an ultraviolet ray or an electron beam, or by heating the resin.
[0187]
<D5> Thereafter, if necessary, as shown in FIG. 17, grinding, polishing or the like may be performed to adjust the thickness of the second substrate 22 with concave portions for microlenses.
[0188]
Thus, a microlens substrate having a biconvex lens as shown in FIG. 15 can be obtained.
[0189]
Thereafter, a black matrix, a transparent conductive film, and the like are formed on the second glass substrate 54 in the same manner as described above, whereby the opposing substrate 1 for a liquid crystal panel can be obtained.
[0190]
Next, a liquid crystal panel (liquid crystal optical shutter) using the liquid crystal panel counter substrate 1 shown in FIG. 10 will be described with reference to FIG.
[0191]
As shown in FIG. 18, a liquid crystal panel (TFT liquid crystal panel) 16 of the present invention includes a TFT substrate (liquid crystal driving substrate) 17, an opposing substrate 1 for a liquid crystal panel joined to the TFT substrate 17, a TFT substrate 17 and a liquid crystal. And a liquid crystal layer 18 made of liquid crystal sealed in a gap between the counter substrate 1 for a panel.
[0192]
The TFT substrate 17 is a substrate for driving the liquid crystal of the liquid crystal layer 18, and is provided near a glass substrate 171, a large number of pixel electrodes 172 provided on the glass substrate 171, and the pixel electrode 172, A large number of thin film transistors (TFTs) 173 corresponding to each pixel electrode 172 are provided.
[0193]
In this liquid crystal panel 16, the TFT substrate 17 and the liquid crystal panel counter substrate 1 are formed such that the transparent conductive film (common electrode) 12 of the liquid crystal panel counter substrate 1 and the pixel electrode 172 of the TFT substrate 17 face each other. They are joined at a fixed distance.
[0194]
The glass substrate 171 is preferably made of quartz glass for the reasons described above.
[0195]
The pixel electrode 172 drives the liquid crystal of the liquid crystal layer 18 by charging and discharging with the transparent conductive film (common electrode) 12. The pixel electrode 172 is made of, for example, the same material as the transparent conductive film 12 described above.
[0196]
The thin film transistor 173 is connected to a corresponding pixel electrode 172 in the vicinity. The thin film transistor 173 is connected to a control circuit (not shown), and controls a current supplied to the pixel electrode 172. Thus, charging and discharging of the pixel electrode 172 are controlled.
[0197]
The liquid crystal layer 18 contains liquid crystal molecules (not shown), and the liquid crystal molecules, that is, the orientation of the liquid crystal changes in response to the charging and discharging of the pixel electrode 172.
[0198]
In the liquid crystal panel 16, usually, one micro lens 8, one opening 111 of the black matrix 11 corresponding to the optical axis Q of the micro lens 8, one pixel electrode 172, and one pixel electrode 172 And one thin film transistor 173 connected to one pixel corresponds to one pixel.
[0199]
The incident light L incident from the side of the substrate 2 with concave portions for microlenses passes through the glass substrate 5 and is condensed when passing through the microlenses 8, while the resin layer 14, the cover glass 13, the openings 111 of the black matrix 11, The light passes through the transparent conductive film 12, the liquid crystal layer 18, the pixel electrode 172, and the glass substrate 171. At this time, since a polarizing plate (not shown) is usually arranged on the incident side of the substrate 2 with concave portions for microlenses, when the incident light L passes through the liquid crystal layer 18, the incident light L It is polarized. At this time, the polarization direction of the incident light L is controlled according to the alignment state of the liquid crystal molecules in the liquid crystal layer 18. Therefore, by transmitting the incident light L transmitted through the liquid crystal panel 16 through a polarizing plate (not shown), the luminance of the emitted light can be controlled.
[0200]
Note that the polarizing plate includes, for example, a base substrate and a polarizing substrate laminated on the base substrate, and the polarizing substrate includes, for example, a polarizing element (an iodine complex, a dichroic dye, or the like) added thereto. Made of resin.
[0201]
As described above, the liquid crystal panel 16 has the microlenses 8, and the incident light L that has passed through the microlenses 8 is condensed and passes through the openings 111 of each black matrix 11. Moreover, the liquid crystal panel facing substrate 1 of the liquid crystal panel 16 is preferably positioned between the substrate 2 with concave portions for microlenses (that is, the microlenses 8 formed in the concave portions 3) and the black matrix 11 as described above. Matching has been made. Therefore, attenuation of the incident light L when passing through the liquid crystal panel 16, particularly the black matrix 11, is suppressed. That is, the liquid crystal panel 16 has a high light transmittance, and can form a bright image with a relatively small amount of light.
[0202]
In the liquid crystal panel 16, for example, after a TFT substrate 17 manufactured by a known method and an opposite substrate 1 for a liquid crystal panel are subjected to an alignment treatment, the two are joined via a sealing material (not shown). The liquid crystal is injected into the gap through a sealing hole (not shown) formed in the gap formed by the method described above, and then the sealing hole is closed. Thereafter, if necessary, a polarizing plate may be attached to the entrance side or the exit side of the liquid crystal panel 16.
[0203]
In the liquid crystal panel 16, a TFT substrate is used as a liquid crystal driving substrate. However, a liquid crystal driving substrate other than the TFT substrate, such as a TFD substrate or an STN substrate, may be used as the liquid crystal driving substrate.
[0204]
In the above-described embodiment, the alignment marks 4 are not left on the liquid crystal panel counter substrate 1 finally obtained. However, the alignment marks 4 are left on the liquid crystal panel counter substrate 1, 16 may be used for positioning when manufacturing.
[0205]
Hereinafter, a projection display device using the liquid crystal panel 16 will be described.
FIG. 19 is a diagram schematically showing the optical system of the projection display device of the present invention.
[0206]
As shown in the figure, the projection display device 300 includes a light source 301, an illumination optical system including a plurality of integrator lenses, a color separation optical system (a light guide optical system) including a plurality of dichroic mirrors, and the like. A liquid crystal light valve (for liquid crystal shutter array) 74 corresponding to red (for red), a liquid crystal light valve (for liquid crystal shutter array) 75 for green (for green), and a liquid crystal light valve (for liquid crystal shutter array) 75 for blue (for blue) A) a liquid crystal light valve (liquid crystal light shutter array) 76; a dichroic prism (color combining optical system) 71 having a dichroic mirror surface 711 that reflects only red light and a dichroic mirror surface 712 that reflects only blue light; A lens (projection optical system) 72.
[0207]
The illumination optical system has integrator lenses 302 and 303. The color separation optical system includes mirrors 304, 306, and 309, a dichroic mirror 305 that reflects blue light and green light (transmits only red light), a dichroic mirror 307 that reflects only green light, and a dichroic that reflects only blue light. A mirror (or a mirror that reflects blue light) 308 and condensing lenses 310, 311, 312, 313, and 314 are provided.
[0208]
The liquid crystal light valve 75 is a first polarized light joined to the liquid crystal panel 16 described above and the incident surface side of the liquid crystal panel 16 (the surface side where the substrate 2 with concave portions for microlenses is located, that is, the side opposite to the dichroic prism 71). Plate (not shown), and a second polarizing plate (not shown) bonded to the emission surface side of the liquid crystal panel 16 (the surface side facing the substrate 2 with concave portions for microlenses, that is, the dichroic prism 71 side). It has. The liquid crystal light valves 74 and 76 have the same configuration as the liquid crystal light valve 75. The liquid crystal panel 16 included in each of the liquid crystal light valves 74, 75, and 76 is connected to a drive circuit (not shown).
[0209]
In the projection display apparatus 300, the dichroic prism 71 and the projection lens 72 constitute an optical block 70. Further, a display unit 73 is constituted by the optical block 70 and liquid crystal light valves 74, 75 and 76 which are fixedly installed with respect to the dichroic prism 71.
[0210]
Hereinafter, the operation of the projection display device 300 will be described.
White light (white light flux) emitted from the light source 301 passes through the integrator lenses 302 and 303. The light intensity (luminance distribution) of this white light is made uniform by the integrator lenses 302 and 303.
[0211]
The white light transmitted through the integrator lenses 302 and 303 is reflected by the mirror 304 to the left in FIG. 19, and the blue light (B) and the green light (G) of the reflected light are respectively reflected by the dichroic mirror 305 in FIG. The red light (R), which is reflected downward, passes through the dichroic mirror 305.
[0212]
The red light transmitted through the dichroic mirror 305 is reflected by the mirror 306 downward in FIG. 19, and the reflected light is shaped by the condenser lens 310 and enters the liquid crystal light valve 74 for red.
[0213]
Of the blue light and the green light reflected by the dichroic mirror 305, the green light is reflected by the dichroic mirror 307 to the left in FIG. 18, and the blue light passes through the dichroic mirror 307.
[0214]
The green light reflected by the dichroic mirror 307 is shaped by the condenser lens 311 and enters the liquid crystal light valve 75 for green.
[0215]
The blue light transmitted through the dichroic mirror 307 is reflected by the dichroic mirror (or mirror) 308 to the left in FIG. 19, and the reflected light is reflected by the mirror 309 to the upper side in FIG. The blue light is shaped by the condenser lenses 312, 313, and 314, and enters the liquid crystal light valve 76 for blue.
[0216]
As described above, the white light emitted from the light source 301 is color-separated into three primary colors of red, green, and blue by the color separation optical system, respectively, guided to the corresponding liquid crystal light valves, and entered.
[0217]
At this time, each pixel (the thin film transistor 173 and the pixel electrode 172 connected thereto) of the liquid crystal panel 16 included in the liquid crystal light valve 74 is subjected to switching control by a driving circuit (driving means) that operates based on a red image signal. (On / off), ie, modulated.
[0218]
Similarly, the green light and the blue light enter the liquid crystal light valves 75 and 76, respectively, and are modulated by the respective liquid crystal panels 16, whereby a green image and a blue image are formed. At this time, each pixel of the liquid crystal panel 16 included in the liquid crystal light valve 75 is subjected to switching control by a driving circuit that operates based on an image signal for green, and each pixel of the liquid crystal panel 16 included in the liquid crystal light valve 76 is controlled for blue. The switching control is performed by a drive circuit that operates based on the image signal of.
[0219]
As a result, the red light, green light, and blue light are modulated by the liquid crystal light valves 74, 75, and 76, respectively, to form a red image, a green image, and a blue image, respectively.
[0220]
The image for red color formed by the liquid crystal light valve 74, that is, the red light from the liquid crystal light valve 74, enters the dichroic prism 71 from the surface 713, is reflected on the dichroic mirror surface 711 to the left in FIG. The light passes through the surface 712 and exits from the exit surface 716.
[0221]
The green image formed by the liquid crystal light valve 75, that is, the green light from the liquid crystal light valve 75 enters the dichroic prism 71 from the surface 714, passes through the dichroic mirror surfaces 711 and 712, and exits. Light exits from surface 716.
[0222]
The image for blue formed by the liquid crystal light valve 76, that is, the blue light from the liquid crystal light valve 76 enters the dichroic prism 71 from the surface 715, and is reflected on the dichroic mirror surface 712 to the left in FIG. The light passes through the dichroic mirror surface 711 and exits from the exit surface 716.
[0223]
Thus, the light of each color from the liquid crystal light valves 74, 75 and 76, that is, each image formed by the liquid crystal light valves 74, 75 and 76 is synthesized by the dichroic prism 71, thereby forming a color image. Is done. This image is projected (enlarged projection) on a screen 320 provided at a predetermined position by the projection lens 72.
[0224]
At this time, since the liquid crystal light valves 74, 75, and 76 include the liquid crystal panel 16 as described above, attenuation when light from the light source 301 passes through the liquid crystal light valves 74, 75, and 76 is suppressed, A bright image can be projected on the screen 320.
[0225]
In the above description, the case where the microlens substrate of the present invention is used for an opposing substrate for a liquid crystal panel, a liquid crystal panel, and a projection display device including the liquid crystal light valve has been described as an example. The present invention is not limited to this, and the microlens substrate of the present invention is used for various electro-optical devices such as a CCD and an optical communication device, an organic or inorganic EL (electroluminescence) display device, and other devices. It goes without saying that you can do it.
[0226]
Further, the display device is not limited to the rear projection type display device. For example, the microlens substrate of the present invention can be used for a front projection type display device.
[0227]
Further, in the above description, the case where the substrate with concave portions of the present invention is applied to a substrate with concave portions for microlenses has been described as an example, but the present invention is not limited to this, and the present invention is not limited thereto. The substrate can be applied to, for example, a reflecting mirror (reflecting plate) in various light emitting sources such as an organic EL (Electro Luminescence) element, a reflecting mirror that reflects light from the light emitting source, and the like.
[0228]
【Example】
(Example 1)
As the target shape of the aspherical surface of the concave portion formed by the substrate with the concave portion for the microlens, the vertical cross-sectional shape of the concave portion is a parabola (Y = 0.1X ² The bottom of -9.8), the depth of the concave portion is set to 7.2 μm, the diameter of the concave portion (diameter on the surface of the substrate) is set to 17.0 μm, and the micrometer provided with the concave portion for the aspherical lens as follows A substrate with a concave portion for a lens was manufactured.
[0229]
First, a quartz glass substrate having a thickness of 1 mm was prepared as a glass substrate.
The quartz glass substrate was immersed in a cleaning solution (80% sulfuric acid + 20% hydrogen peroxide solution) heated to 85 ° C. to perform cleaning and clean the surface.
[0230]
-1A- Next, a 0.08 μm thick SiO 2 was formed on the quartz glass substrate as a control film by a CVD method. ₂ A film was formed.
[0231]
The etching rate a of this control film with respect to the etching solution was adjusted to be 0.11 μm / min. The etching rate b of the quartz glass substrate with respect to the etching solution was 0.1 μm / min, and the etching rate ratio a / b was 1.1.
[0232]
-2A- Next, the quartz glass substrate was placed in a CVD furnace set at 600 ° C. and 80 Pa, and SiH ₄ Was supplied at a rate of 300 mL / min, and a polycrystalline silicon film having a thickness of 0.50 μm was formed as a mask film and a back surface protective layer by the CVD method.
[0233]
Thus, the control film (SiO 2) is formed on the front side of the quartz glass substrate. ₂ A film) and a mask film (polycrystalline silicon film) were laminated in this order to form a mask.
[0234]
-3A- Next, a resist having a microlens pattern is formed on the formed mask by using a photoresist, and then the mask is subjected to dry etching with CF gas, and then the resist is removed. Then, a circular opening was formed (see FIG. 1B).
The diameter of the opening was adjusted to be 1.0 μm.
[0235]
In Example 1, no hole was provided at a position corresponding to the opening of the quartz glass substrate.
[0236]
-4A- Next, wet etching was performed on the quartz glass substrate to form a large number of concave portions on the quartz glass substrate (see FIG. 2D).
[0237]
The etching time of this wet etching was set to 72 minutes, and a hydrofluoric acid-based etching solution was used as the etching solution.
[0238]
-5A- Next, dry etching was performed using CF gas to remove the mask and the back surface protective layer.
[0239]
As a result, a wafer-shaped substrate with concave portions for microlenses having a large number of concave portions for aspherical lenses formed on a quartz glass substrate was obtained. Although not described, a cross-shaped alignment mark having a circular opening at the center was also formed on the quartz glass substrate (see FIG. 11).
[0240]
FIG. 20 shows a longitudinal sectional shape (shown by a solid line in the figure) of a concave portion of the obtained substrate with a concave portion for a microlens, and a parabola (Y = 0.1X) as a target shape. ² -9.8) (shown by a dotted line in the figure).
[0241]
FIG. 20 also shows a mask having an opening before wet etching.
[0242]
In the graph of FIG. 20, the surface of the quartz glass substrate coincides with the X axis.
[0243]
(Example 2)
As the target shape of the aspherical surface of the concave portion formed by the substrate with the concave portion for the microlens, the vertical cross-sectional shape of the concave portion is a parabola (Y = 0.1X ² The bottom of -9.8), the depth of the concave portion was set to 10.0 μm, and the diameter of the concave portion (diameter on the surface of the substrate) was set to 20.0 μm. Except for (1) to (4), a substrate with concave portions for microlenses was obtained in the same manner as in Example 1.
[0244]
(1) Control film (SiO ₂ The etching rate a of the film) with respect to the etching solution was adjusted to be 0.108 μm / min. The etching rate b of the quartz glass substrate with respect to the etching solution was 0.1 μm / min, and the etching rate ratio a / b was 1.08.
[0245]
{Circle around (2)} The diameter of the opening of the mask was adjusted to be 6.0 μm.
{Circle around (3)} A bottomed hole extending in the thickness direction of the quartz glass substrate and having a circular shape in plan view is provided at the center of the opening of the quartz glass substrate.
[0246]
In this case, a resist having a predetermined pattern is formed by a photoresist on a mask and a quartz glass substrate. ₃ Dry etching with a gas was performed, and then the resist was removed to form a hole in the quartz glass substrate (see FIG. 6 (i)).
[0247]
The depth of the hole was adjusted to 3.5 μm, and the diameter was adjusted to 1 μm.
{Circle around (4)} The etching time was set to 65 minutes.
[0248]
FIG. 21 shows a vertical cross-sectional shape (shown by a solid line in the figure) of a concave portion of the obtained substrate with a concave portion for microlenses and a parabola (Y = 0.1X) as a target shape. ² -9.8) (shown by a dotted line in the figure).
[0249]
FIG. 21 also shows a mask having an opening before wet etching and a hole formed in a quartz glass substrate.
[0250]
In the graph of FIG. 21, the surface of the quartz glass substrate coincides with the X axis.
[0251]
(Evaluation)
In Example 1, the depth of the concave portion was set to 7.2 μm and the diameter of the concave portion was set to 17.0 μm. However, when the formed concave portions were measured, they agreed with the set values.
[0252]
Similarly, in Example 2, the depth of the concave portion was set to 10.0 μm, and the diameter of the concave portion was set to 20.0 μm. However, when the formed concave portions were measured, they matched the set values.
[0253]
Then, as shown in FIGS. 20 and 21, in Examples 1 and 2, the vertical cross-sectional shape of the concave portion was parabolic (Y = 0.1X ² −9.8), and a recess having a substantially target shape could be formed.
[0254]
Thus, according to the present invention, it is understood that a desired aspherical concave portion can be formed by performing wet etching while appropriately adjusting predetermined conditions.
[0255]
(Example 3)
Using the substrate with concave portions for microlenses obtained in Example 1, an opposing substrate for a liquid crystal panel was manufactured as follows.
[0256]
-1B- First, a cover glass was bonded to the surface of the substrate with concave portions for microlenses, on which the concave portions were formed, using an ultraviolet (UV) curable epoxy-based optical adhesive (refractive index: 1.59).
[0257]
In addition, thereby, the microlens made of the optical adhesive filled in the concave portion of the substrate with concave portions for microlenses was formed on the resin layer composed of the cured optical adhesive.
[0258]
-2B- Next, the joined cover glass was ground and polished to a thickness of 50 μm.
[0259]
-3B- Next, a black matrix having openings was formed on the cover glass. This was performed as follows. First, a 0.16 μm thick Cr film was formed on a cover glass by sputtering. Next, a resist film was formed on the Cr film. Next, using the alignment mark as an index, exposure was performed using an exposure machine such that each opening of the black matrix pattern coincided with the optical axis of each microlens, thereby forming a black matrix pattern on the resist film. Next, wet etching was performed using a cerium ammonium nitrate aqueous solution as a stripping solution to form an opening of a black matrix in the Cr film. Next, the resist film was removed.
At this time, the alignment mark was used as an index for positioning.
[0260]
-4B- Next, an ITO film (transparent conductive film) having a thickness of 0.15 μm was formed on the cover glass by sputtering so as to cover the black matrix.
Thus, a wafer including a plurality of opposing substrates for a liquid crystal panel was obtained.
[0261]
-5B- Finally, the wafer was cut using a dicing apparatus to obtain a counter substrate for a liquid crystal panel. When the substrate with concave portions for microlenses is obtained as an individual substrate, the counter substrate for a liquid crystal panel can also be obtained as an individual substrate, so there is no need to cut and separate the wafer.
[0262]
(Example 4)
A counter substrate for a liquid crystal panel was obtained in the same manner as in Example 3 using the substrate with concave portions for microlenses obtained in Example 2 above.
[0263]
(Comparative example)
In the manufacture of the substrate with concave portions for microlenses, a wet etching is performed by forming only a mask film without forming a control film as in Example 1, and a large number of concave portions (hemispherical concave portions) for spherical lenses are formed. The formed substrate with concave portions for microlenses was obtained, and a facing substrate for liquid crystal panel was obtained in the same manner as in Example 3 using the substrate with concave portions for microlenses.
[0264]
(Evaluation)
When light was made incident on the counter substrate for a liquid crystal panel obtained in Examples 3 and 4 from the side of the substrate with concave portions for microlenses and light was transmitted, the light was effectively transmitted to the openings of the black matrix. It was guided and a bright outgoing light could be obtained.
[0265]
The light transmittance of the liquid crystal panel opposing substrate of the comparative example (spherical lens) was 1.6 times that of the liquid crystal panel opposing substrate having no microlens, whereas Example 3 Excellent transmittance of 1.8 times for the liquid crystal panel opposing substrate (aspherical lens) and 1.9 times for the liquid crystal panel opposing substrate of Example 4 (aspherical lens). Was confirmed.
[0266]
(Example 5)
Further, using the opposing substrates for the liquid crystal panels obtained in Examples 3 and 4, TFT liquid crystal panels having the structure shown in FIG. 18 were assembled.
[0267]
All of the assembled TFT liquid crystal panels had high light transmittance similarly to the counter substrate for liquid crystal panel.
[0268]
Therefore, it is easily presumed that a projection display device using such a liquid crystal panel can project a bright image on a screen.
[0269]
As described above, the present invention has been described based on the illustrated embodiments and examples, but the present invention is not limited to this, and the configuration of each unit is replaced with an arbitrary configuration having a similar function. be able to.
[0270]
Further, in the present invention, any two or more configurations (features) of the above embodiments may be appropriately combined.
[0271]
【The invention's effect】
As described above, according to the present invention, a desired aspherical concave portion can be easily and reliably formed on a substrate by appropriately adjusting predetermined conditions and performing wet etching on the substrate. As a result, it is possible to obtain a substrate with a concave portion having a desired aspheric concave portion.
[0272]
Thus, for example, a substrate with concave portions for microlenses corresponding to an aspherical lens in which spherical aberration is suppressed can be easily and reliably manufactured.
[0273]
That is, a microlens concave portion (aspherical microlens concave portion) corresponding to a suitable aspherical lens can be formed on the substrate by wet etching, thereby reducing the spherical aberration of the microlens ( Or substantially eliminated).
[0274]
Further, according to the present invention, it is possible to provide a microlens substrate, a counter substrate for a liquid crystal panel, and a liquid crystal panel, which have reduced spherical aberration, high light transmittance, and excellent optical characteristics.
[0275]
Further, according to the present invention, it is possible to provide a projection display device capable of projecting a bright image.
[Brief description of the drawings]
FIG. 1 is a schematic longitudinal sectional view showing a first embodiment of a method for manufacturing a substrate with concave portions for microlenses when the substrate with concave portions of the present invention is applied to a substrate with concave portions for microlenses.
FIG. 2 is a schematic longitudinal sectional view showing a first embodiment of a method for manufacturing a substrate with concave portions for microlenses when the substrate with concave portions of the present invention is applied to a substrate with concave portions for microlenses.
FIG. 3 is a schematic longitudinal sectional view showing a first embodiment of a method for manufacturing a substrate with concave portions for microlenses when the substrate with concave portions of the present invention is applied to a substrate with concave portions for microlenses.
FIG. 4 is a schematic longitudinal sectional view showing a second embodiment of a method for manufacturing a substrate with concave portions for microlenses when the substrate with concave portions of the present invention is applied to a substrate with concave portions for microlenses.
FIG. 5 is a schematic longitudinal sectional view showing a third embodiment of a method for manufacturing a substrate with concave portions for microlenses when the substrate with concave portions of the present invention is applied to a substrate with concave portions for microlenses.
FIG. 6 is a schematic longitudinal sectional view showing a third embodiment of a method for manufacturing a substrate with concave portions for microlenses when the substrate with concave portions of the present invention is applied to a substrate with concave portions for microlenses.
FIG. 7 is a schematic longitudinal sectional view showing a third embodiment of a method for manufacturing a substrate with concave portions for microlenses when the substrate with concave portions of the present invention is applied to a substrate with concave portions for microlenses.
FIG. 8 is a schematic longitudinal sectional view showing a third embodiment of a method for manufacturing a substrate with concave portions for microlenses when the substrate with concave portions of the present invention is applied to a substrate with concave portions for microlenses.
FIG. 9 is a schematic longitudinal sectional view illustrating a method for manufacturing a counter substrate for a liquid crystal panel according to the present invention.
FIG. 10 is a schematic longitudinal sectional view showing a counter substrate for a liquid crystal panel of the present invention.
FIG. 11 is a schematic plan view showing a substrate with concave portions for microlenses of the present invention.
FIG. 12 is a schematic longitudinal sectional view showing a method for manufacturing a microlens substrate of the present invention.
FIG. 13 is a schematic longitudinal sectional view showing a method for manufacturing a microlens substrate according to the present invention.
FIG. 14 is a schematic longitudinal sectional view showing a microlens substrate of the present invention.
FIG. 15 is a schematic longitudinal sectional view showing a microlens substrate of the present invention.
FIG. 16 is a schematic longitudinal sectional view illustrating a method for manufacturing a microlens substrate of the present invention.
FIG. 17 is a schematic longitudinal sectional view illustrating the method for manufacturing a microlens substrate of the present invention.
FIG. 18 is a schematic longitudinal sectional view showing a liquid crystal panel of the present invention.
FIG. 19 is a diagram schematically showing an optical system of a projection display device of the present invention.
FIG. 20 is a vertical sectional view of a concave portion of the substrate with concave portions for microlenses of Example 1, and a parabolic curve (Y = 0.1X) as a target shape. ² -9.8).
FIG. 21 is a vertical sectional view of a concave portion of the substrate with concave portions for microlenses according to the second embodiment, and a parabola (Y = 0.1X) as a target shape. ² -9.8).
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Counter substrate for liquid crystal panels, 2 ... Substrate with concave part for microlenses, 21 ... Substrate with concave part for microlenses, 22 ... Substrate with concave part for second microlenses, 3 ... recess, 36 ... first recess, 37 ... second recess, 4 ... alignment mark, 41 ... corner, 42 ... first alignment mark, 43 ... 2nd alignment mark, 44 opening, 5 glass substrate, 51 transparent substrate, 52 glass substrate, 53 first glass substrate, 54 second , Glass substrate, 55 ... hole, 6 ... mask, 61 ... control film, 611 ... unit film, 62 ... mask film, 63 ... second mask, 64 ... -Opening, 65-Third mask, 69-Backside protective layer, 8-Microphone Lens, 9: spacer, 99: effective lens area, 100: non-effective lens area, 11: black matrix, 111: opening, 12: transparent conductive film, 13: Cover glass, 14 resin layer, 141, 142 resin layer, 143, 144 resin, 16 liquid crystal panel, 17 TFT substrate, 171 glass substrate, 172 ..Pixel electrode, 173 thin film transistor, 18 liquid crystal layer, 70 optical block, 71 dichroic prism, 711, 712 dichroic mirror surface, 713 to 715 surface, 716: Emission surface, 72: Projection lens, 73: Display unit, 74 to 76: Liquid crystal light valve, 300: Projection display device, 301: Light source, 3 2,303 ... integrator lens, 304,306,309 ... mirror, 305,307,308 ... dichroic mirror, 310-314 ... condenser lens, 320 ... screen

Claims (25)

Forming a mask having a predetermined pattern of openings on a substrate, the mask including a control film having a higher etching rate with respect to an etchant than the substrate, and a mask having a predetermined pattern; When,
Performing a wet etching using the mask, and forming a concave portion on the substrate, a method for manufacturing a substrate with concave portions,
A substrate having a concave portion, wherein a desired aspheric concave portion is formed by performing wet etching by appropriately adjusting the conditions of the opening, the etching rate of the control film with respect to an etching solution, and the etching time. Manufacturing method. Forming a mask having a predetermined pattern of openings on a substrate, the mask including a control film having a higher etching rate with respect to an etchant than the substrate, and a mask having a predetermined pattern; When,
Forming a hole extending in the thickness direction of the substrate at a position corresponding to the opening of the substrate;
Performing a wet etching using the mask, and forming a concave portion on the substrate, a method for manufacturing a substrate with concave portions,
The desired aspherical concave portion is formed by performing wet etching by appropriately adjusting the conditions of the opening, the hole, the etching rate of the control film with respect to the etchant, and the etching time. Manufacturing method of a substrate with a concave portion. The method according to claim 2, wherein adjusting the hole is adjusting a depth of the hole. 4. The method according to claim 2, wherein the formation of the hole is performed by dry etching. The method for manufacturing a substrate with concave portions according to claim 1, wherein adjusting the opening is adjusting the size of the opening. 5. The method according to claim 1, wherein a shape of the opening in a plan view is substantially circular, and the adjustment of the opening is an adjustment of a diameter of the opening. The method for manufacturing a substrate with concave portions according to claim 1, wherein the plurality of concave portions are formed by forming the plurality of openings. The ratio a / b of the etching rate is adjusted to 1.01 or more, where a is an etching rate of the control film with respect to an etching solution and b is an etching rate of the substrate with respect to the etching solution. A method for manufacturing a substrate with concave portions according to any one of the above. 9. The method according to claim 1, wherein the control film is made of silicon oxide. The method for manufacturing a substrate with concave portions according to claim 1, wherein the control film is formed by a chemical vapor deposition method. 11. The method according to claim 1, wherein the mask film is made of polycrystalline silicon. The method according to claim 1, wherein the substrate is a quartz glass substrate. The method for manufacturing a substrate with a concave portion according to claim 1, wherein each of the conditions is adjusted such that at least a part of the aspheric surface of the concave portion to be formed includes a paraboloid or a surface similar thereto. . 14. The method for manufacturing a substrate with concave portions according to claim 1, further comprising a step of removing the mask. The method according to claim 1, wherein the recess is a microlens recess. A substrate with concave portions manufactured by the method for manufacturing a substrate with concave portions according to claim 1. A substrate with concave portions for microlenses, manufactured by the method for manufacturing a substrate with concave portions according to claim 15. A microlens substrate manufactured using the substrate with concave portions for microlenses according to claim 17 and having a plurality of microlenses. The microlens substrate according to claim 18, wherein the microlens is a biconvex microlens. A substrate for a first microlens recess having a plurality of aspherical first microlens recesses according to claim 17, and a second microlens having a plurality of aspherical second microlens recesses. The substrate with the concave portion is bonded to the substrate with the concave portion for the first microlens via a resin such that the concave portion for the first microlens and the concave portion for the second microlens face each other. A microlens substrate, comprising: a biconvex microlens formed between the second microlens recessed substrate. An opposing substrate for a liquid crystal panel, comprising the microlens substrate according to claim 18. A liquid crystal panel comprising the counter substrate for a liquid crystal panel according to claim 21. 22. A liquid crystal driving substrate provided with pixel electrodes, a liquid crystal panel opposing substrate according to claim 21 joined to the liquid crystal driving substrate, and liquid crystal sealed in a gap between the liquid crystal driving substrate and the liquid crystal panel opposing substrate. A liquid crystal panel comprising: The liquid crystal panel according to claim 23, wherein the liquid crystal driving substrate is a TFT substrate. A projection type display device comprising the liquid crystal panel according to any one of claims 22 to 24.

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