JP2005141155A - Substrate for electrooptic device and its manufacturing method, electrooptic device and its manufacturing method, exposure mask and electronic appliance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a reflecting layer having a favorable light scattering effect by a simple manufacturing process. <P>SOLUTION: An exposure mask 7a is used for an exposure process to roughen a region 511 to be processed of a film body 51. The exposure mask 7a has a first region 71 and a second region 72. The first region 71 functions as a light transmitting region to transmit light incident to the periphery of the region 511 to be processed; the second region 72 includes a plurality of dot regions 721 having each having a light shielding portion 84 to cut the light incident to the region 511 to be processed, and has a semitransmitting portion 86 in a region excluding the dot region 721, with the semitransmitting portion transmitting the light incident to the region 511 to be processed with a lower transmittance than in the transmitting region 81. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a technique for scattering reflected light by making the surface of a reflective layer rough.

  In a so-called reflective liquid crystal display device, a reflective layer having light reflectivity is formed on a plate surface of a substrate holding liquid crystal. Then, external light such as sunlight and indoor illumination light incident from the observation side is reflected on the surface of the reflective layer, and this reflected light is used for image display. In this configuration, if the surface of the reflective layer is a perfect plane, the incident light on the liquid crystal display device is specularly reflected by the surface of the reflective layer and viewed by an observer. In this case, in addition to the original display image, there is a problem that an image of a person or an object facing the display surface of the liquid crystal display device is visually recognized, making it difficult to see the display.

  In order to prevent such reflection of the background, a large number of fine protrusions and depressions (hereinafter referred to as “scattering structures”) are formed on the surface of the reflective layer. According to this configuration, reflected light on the surface of the reflective layer is appropriately scattered and emitted to the observation side, so that reflection of the background can be prevented. Patent Document 1 discloses a method for forming this scattering structure. In this method, first, a large number of fine resin pieces are formed dispersed on the plate surface of the substrate, and secondly, in order to smooth the steps between these protrusions and the plate surface of the substrate. A film body covering the protrusion is provided, and third, a reflective layer is formed so as to cover the film body.

Japanese Patent Laying-Open No. 2003-75987 (paragraph 0073 and paragraph 0074 and FIG. 12)

  However, this method requires a process of forming a film body covering each protrusion in addition to the process of forming a large number of fine resin pieces on the substrate, which complicates the manufacturing process and increases the manufacturing cost. The problem can arise. As a measure for solving this problem, it is conceivable to form a reflective layer so as to directly cover each resin piece without forming a film body. However, when this method is used, a flat surface reflecting the plate surface of the substrate exposed between the resin pieces and the flat surface at the top of each resin piece appears on the surface of the reflective layer, so that light is scattered. This may cause a problem that the effect (hereinafter referred to as “light scattering effect”) cannot be sufficiently obtained. This invention is made | formed in view of such a situation, The objective is to obtain the reflection layer which has a favorable light-scattering effect by a simple manufacturing process.

  In order to solve the above problems, an exposure mask according to the present invention has the following configuration. First, the exposure mask is opposed to a processing region and a first region that is opposed to the periphery of the processing region whose surface is to be roughened (that is, a region other than the processing region). A second region. Among these, the second region further has a plurality of dot regions. These regions (that is, three types of regions including the first region, each dot region, and the second region excluding each dot region) include a light transmitting portion that transmits light and a light blocking portion that blocks light. In addition, a semi-transmissive portion that transmits light with a light transmittance lower than that of the light-transmissive portion is provided. Whether a light-transmitting part, a light-shielding part, or a semi-transmitting part is provided in each region is determined depending on the type (positive type or negative type) of the photosensitive material used to form the film body to be processed and finally created. It selects suitably according to the form of the rough surface.

  For example, by removing areas other than a plurality of dot areas from a processed area of a film body made of a positive photosensitive material, a rough surface (that is, a rough surface in which an area corresponding to the dot area of the film body is a projection) is formed. The exposure mask for forming the surface is provided with a plurality of first regions each having a light-transmitting portion that transmits light toward the periphery of the region to be processed and a light shielding portion that blocks light toward the region to be processed. And a second region provided in a region other than each dot region, and a semi-transmissive portion that transmits light toward the region to be processed with a light transmittance lower than that of the light-transmitting portion. A specific example of this configuration will be described later as the first embodiment. On the other hand, a rough surface (that is, a rough surface in which a region corresponding to the dot region of the film body is recessed) is removed by removing a plurality of dot regions from the processed region of the film body made of a positive photosensitive material. The exposure mask to be formed transmits a first region having a translucent portion that transmits light toward the periphery of the region to be processed, and transmits light toward the region to be processed with a light transmittance lower than that of the translucent portion. The semi-transmission part has a plurality of dot areas provided in each, and the light-shielding part that blocks the light toward the process area has a second area provided in an area other than each dot area. A specific example of this configuration will be described later as a second embodiment.

  Since the first region of these exposure masks is a translucent portion, light can be applied to the entire region of the film body around the region to be processed in the thickness direction. On the other hand, in the second region of the exposure mask, a light-shielding portion is provided in one of the dot regions and the other regions, and a semi-transmissive portion is provided in the other region. According to this configuration, the amount of light transmitted from the light source toward the film body through the second region is limited, and therefore, the region around the processing region of the film body is photodecomposed over the entire thickness direction. Even if a sufficient amount of light is irradiated from the light source, only a part of the film body in the thickness direction can be selectively photodecomposed. For this reason, even if the film body is developed, the processed region is not completely removed, so that the surface of the substrate provided with the film body is not exposed in the processed region. Therefore, the electro-optical device substrate (reflective substrate) using the base layer obtained by developing the film body exposed through the exposure mask has no flat surface reflecting the flat surface of the substrate and has a good light scattering effect. To demonstrate. Moreover, according to the exposure mask of the present invention, the light acts only on the part of the film body where the light acts completely over the entire thickness direction, the part where the exposure is not performed, and a part of the thickness direction. Can be obtained in a common process.

  In other aspects of these exposure masks, a peripheral light-transmitting portion is provided so as to be in contact with the entire periphery of each dot region or a part of the periphery. Each peripheral translucent portion is a portion that transmits light with substantially the same light transmittance as the translucent portion of the first region. According to this configuration, the light transmitted from the light source to the film body and transmitted through the peripheral light transmitting portion is diffracted at the periphery of each dot region, and the diffracted light reaches the surface of the film body and strengthens it. Accordingly, in addition to the portion irradiated with light transmitted through the semi-transmissive portion of the film body, the portion irradiated with diffracted light transmitted through the peripheral light transmitting portion is also photodegraded, and thus obtained by developing this film body. A minute depression will be formed in the region corresponding to the dot region in the underlying layer. If the reflective layer is formed in a thin film on such a rough surface of the underlayer, the light is better than when the reflective layer is formed on the rough surface where the top of the protrusion or the bottom of the recess is a flat surface. A scattering effect is obtained.

  On the other hand, by removing areas other than the plurality of dot areas from the processed area of the film body made of the negative photosensitive material, the rough surface (that is, the rough area in which the area corresponding to the dot area of the film body is a projection). The exposure mask for forming the surface is provided with a first region provided with a light blocking portion that blocks light traveling toward the periphery of the processing region and a light transmitting portion that transmits light traveling toward the processing region. A plurality of dot regions, and a second region provided in a region other than each dot region, wherein a semi-transmissive portion that transmits light toward the processing region with a light transmittance lower than that of each light-transmitting portion is provided. . A specific example of this configuration will be described later as a third embodiment. Further, by removing a plurality of dot regions from the processed region of the film body made of a negative photosensitive material, a rough surface (that is, a rough surface in which the region corresponding to the dot region of the film body is recessed) is obtained. The exposure mask to be formed includes a plurality of first regions each provided with a light-shielding portion that blocks light traveling toward the periphery of the processing region, and semi-transmission portions that transmit light traveling toward the processing region. The translucent part which has a dot area and transmits light toward the work area is a second area provided in an area other than each dot area, and the light transmittance of the semi-transmissive part is the light transmission of the translucent part. And a second region lower than the rate. A specific example of this configuration will be described later as a fourth embodiment. Even with these exposure masks, the underlayer of the reflective layer having a good light scattering effect can be formed by a simple process in the same manner as the exposure mask for exposing the positive photosensitive material described above. it can.

  By the way, it is necessary to irradiate a sufficient amount of light from the light source in order to completely remove the periphery of the region to be processed in the film body. If the light transmittance of the semi-transmissive portion in the exposure mask used in such an exposure process is relatively high, the amount of light that passes through the semi-transmissive portion and reaches the region to be processed increases. There is a possibility of photolysis over the entire thickness direction. However, if the region to be processed is removed as described above, the plate surface of the substrate is exposed and may cause a reduction in the light scattering effect. In order to prevent this problem, it is desirable that the light transmittance of the semi-transmissive portion is sufficiently lower than the light transmittance of the light-transmissive portion. According to the test by the inventor of the present application, a rough surface capable of realizing a particularly good light scattering effect is formed by setting the light transmittance of the semi-transmissive portion with respect to the irradiation light from the light source to 10% (percent) or more and 40% or less. It came to obtain the knowledge that it is done. Therefore, it is desirable that the light transmittance of the semi-transmissive portion in the exposure mask according to the present invention be 10% or more and 40% or less.

  In addition, if it has a light transmittance lower than a translucent part, the specific structure of a semi-transmissive part is arbitrary. For example, if a light-shielding film body is formed very thin, part of the light irradiated to the thin film is absorbed or reflected, while the other part transmits the thin film. Such a light-shielding thin film may be used as the semi-transmissive portion. Alternatively, a plurality of micro light-shielding portions having light shielding properties and a plurality of micro light-transmitting portions having translucency may be used as a semi-transmissive portion. With this configuration as well, a part of the light emitted from the light source is shielded by the minute light shielding part, while the other part can be transmitted from the minute light transmitting part. The arrangement of the micro light-shielding part and the micro light-transmitting part is arbitrary, but from the viewpoint of uniformizing the amount of light transmitted through the semi-transmissive part and reaching the film body in the plane of the semi-transmissive part, It is desirable to use a semi-transmissive portion having a configuration in which the micro light-shielding portions and the micro light-transmitting portions are alternately arranged in the first direction and the second direction (that is, a configuration arranged in a checkered pattern). In this configuration, in order to prevent the light transmitted through the minute light-transmitting portion from being diffracted at the periphery of the minute light-shielding portion and interfering with each other, each minute light-shielding portion and each side of each minute light-transmitting portion are prevented. The length is desirably 2 μm (micrometer) or less, more preferably 1.5 μm or less. On the other hand, as another aspect of the semi-transmissive portion, a configuration in which the micro light-shielding portions and the micro light-transmitting portions each extending in the first direction are alternately arranged in the second direction orthogonal to the first direction ( That is, a configuration in which minute light-shielding portions and minute light-transmitting portions are arranged in a stripe shape may be employed. Also in this configuration, in order to prevent interference of diffracted light, the width of each minute light-shielding portion and each minute light-transmitting portion is desirably 2 μm or less, and more preferably 1.5 μm or less.

  In another aspect of the exposure mask according to the present invention, the planar shape of each dot region is a polygon. Here, if the area of each dot region is too large, a flat surface appears at the top of the protrusion constituting the rough surface of the film body or at the bottom of the recess, so that the light scattering effect of the reflective layer formed on the rough surface Will be damaged. On the other hand, if the area of each dot region is too small, the light from the diffracted light source interferes in the vicinity of the boundary between each dot region and the other region in the second region, and the surface shape of the film body is expected. The shape may not be According to the test by the inventors of the present application, it has been found that the diameter of the circumscribed circle of each polygon is desirably 8 μm or more and 11 μm or less. Therefore, the diameter of the polygon circumscribed circle of each dot region is desirably 8 μm or more and 11 μm or less, and more preferably 9 μm or more and 10 μm or less.

  Also, if each dot area is too dense or extremely sparse, the flatness of the rough surface obtained by development after exposure increases, and this reduces the light scattering effect of the reflective layer on the rough surface. There is no doubt. According to the test by the inventor of the present application, it has been found that the ratio of the area of the plurality of dot regions to the total area of the first region and the second region is desirably 30% or more and 60% or less.

  The present invention can also be specified as a method of manufacturing an electro-optical device substrate using the exposure mask described above. More specifically, the first feature of the method for manufacturing a substrate for an electro-optical device according to the present invention is that a film body is formed using a positive photosensitive material, and the film body is exposed through a mask. The light from the light source that goes to one of the region that should become a projection on the rough surface and the region that should become a depression is blocked by the light shielding portion of the exposure mask, and the light from the light source that goes to the other of these regions An exposure step in which the light is allowed to act on only a part in the thickness direction of the film body by transmitting the light through the translucent portion of the exposure mask, and a development step in which the film body that has undergone the exposure process is developed to form a base layer And a reflective layer forming step of forming a reflective layer having light reflectivity on the rough surface of the underlayer obtained by the developing step. Furthermore, the second feature of the method for manufacturing the substrate for an electro-optical device according to the present invention is that a film body is formed using a negative photosensitive material, and the film body is exposed through an exposure mask. A step of transmitting light from a light source directed to one of a region to be a rough projection and a region to be a depression to the whole thickness direction of the film body by transmitting the light from the light transmitting portion of the exposure mask. An exposure step of causing light to act on only a part in the thickness direction of the film body by transmitting light from a light source directed to the other of these regions through a semi-transmissive portion of the exposure mask; A developing step of developing the film body after the exposure step to form a base layer, and a reflective layer forming step of forming a reflective layer having light reflectivity on the rough surface of the base layer obtained by the developing step It is in. According to these manufacturing methods, for the same reason as described above for the exposure mask according to the present invention, an electro-optical device substrate having a good light scattering effect can be obtained by a simple manufacturing process.

  An electro-optical device is manufactured by arranging an electro-optical material so as to face the reflective layer of the electro-optical device substrate obtained by these manufacturing methods. According to this manufacturing method, an electro-optical device having a good display quality with less reflection of the background is manufactured by a simple process. The electro-optical material in the present invention is a material that converts an electrical action such as voltage application or current supply into a change in optical characteristics such as a change in light transmittance or luminance. A typical example of the electro-optical material is liquid crystal, but the applicable range of the present invention is not limited to this.

  In addition, the electro-optical device substrate according to the present invention includes a base layer having a plurality of protrusions each having a depression formed on the top thereof, and light provided on the surface of the base layer having the plurality of protrusions. And a reflective layer having reflectivity. Here, if the surface of the protrusion of the underlayer is a smooth surface as described in Patent Document 1, the same smooth surface appears on the surface of the reflective layer provided on the surface. On such a smooth surface, light is specularly reflected, so that even if the surface of the reflective layer is rough, a good light scattering effect is not always obtained. On the other hand, since the base layer of the substrate for an electro-optical device according to the present invention has a plurality of protrusions with depressions formed on the top of each, the ratio of the flat surface on the surface of the reflective layer is disclosed in Patent Document 1. Less than the reflective layer described in. Therefore, the electro-optical device substrate according to the present invention can provide a good light scattering effect. The underlayer of the electro-optical device substrate according to the present invention can be obtained, for example, by developing after exposing a film body using the above-described exposure mask in which a peripheral light-transmitting portion is provided in a dot region.

  The substrate for an electro-optical device according to the present invention is used as a substrate for an electro-optical device. In other words, the electro-optical device includes a first substrate and a second substrate that face each other and sandwich an electro-optical material, and layers provided on a plate surface of the second substrate that faces the electro-optical material. A base layer having a plurality of protrusions with depressions formed on the top thereof, and a reflective layer having light reflectivity provided on the surface of the base layer having the plurality of protrusions. According to this electro-optical device, incident light from the first substrate side can be favorably scattered by the reflective layer and then reflected to the first substrate side, so that a good display quality with reduced reflection of the background can be achieved. Is obtained. Furthermore, the present invention is also specified as an electronic apparatus including the electro-optical device as a display device. As this type of electro-optical device, various electro-optical devices such as a mobile phone and a personal computer are conceivable.

  As described above, according to the present invention, a reflective layer having a good light scattering effect can be obtained by a simple manufacturing process.

  Embodiments of the present invention will be described with reference to the drawings. In the following, a mode in which the present invention is applied to a liquid crystal display device using liquid crystal as an electro-optical material will be exemplified, but the scope to which the present invention can be applied is not limited to this. In the drawings shown below, the dimensions and ratios of the constituent elements are different from actual ones for convenience of explanation.

<A: First Embodiment>
<A-1: Configuration of liquid crystal display device>
FIG. 1 is a cross-sectional view illustrating a configuration of a liquid crystal display device according to the present embodiment, and FIG. 2 is a perspective view illustrating a part of the liquid crystal display device in an enlarged manner. A sectional view taken along line II in FIG. 2 corresponds to FIG. As shown in these drawings, the liquid crystal display device 100 includes a first substrate 10 and a second substrate 20 arranged so as to face each other through a sealing material 34 formed in a substantially rectangular frame shape. Have. These substrates are plate-like or film-like members made of a light-transmitting material such as glass or plastic. For example, a TN (Twisted Nematic) type liquid crystal 35 is sealed in a space surrounded by both substrates and the sealing material 34. In the following, as shown in FIGS. 1 and 2, the first substrate 10 side as viewed from the liquid crystal 35 is referred to as “observation side”. That is, it means the side where an observer who visually recognizes a display image by the liquid crystal display device 100 is located. On the other hand, when viewed from the liquid crystal 35, the second substrate 20 side is referred to as “back side”. A retardation plate 311 for improving the contrast of a display image and a polarizing plate 312 for polarizing incident light are attached to the observation-side plate surface of the first substrate 10. A similar retardation plate 321 and polarizing plate 322 are attached on the rear plate (not shown in FIG. 2). Further, the second substrate 20 has a portion (hereinafter referred to as “projected portion”) 20 a that projects from the periphery of the first substrate 10. An IC chip 38 having a circuit for driving the liquid crystal display device 100 is mounted on the overhanging portion 20a by a COG (Chip On Glass) technique.

  A plurality of pixel electrodes 11 are arranged in a matrix on the surface of the first substrate 10 facing the liquid crystal 35. Each pixel electrode 11 is a substantially rectangular electrode made of a conductive material having optical transparency such as ITO (Indium Tin Oxide). A scanning line 12 extending in the Y direction is formed in the gap between the pixel electrodes 11 adjacent in the X direction. Each pixel electrode 11 is connected to the scanning line 12 via a TFD (Thin Film Diode) element 13. The TFD element 13 is a two-terminal switching element having non-linear current-voltage characteristics. The plate surface of the first substrate 10 on which these elements are formed is covered with an alignment film 14 that has been subjected to a rubbing process (not shown in FIG. 2).

  On the other hand, a plurality of data lines 27 extending in the X direction are formed on the plate surface of the second substrate 20 facing the liquid crystal 35. Each data line 27 is an electrode made of a light-transmitting conductive material such as ITO, like the pixel electrode 11, and faces the plurality of pixel electrodes 11 that are arranged in the X direction on the first substrate 10. The plate surface of the second substrate 20 on which the data lines 27 are formed is covered with an alignment film 28 similar to the alignment film 14. With this configuration, the liquid crystal 35 sandwiched between the first substrate 10 and the second substrate 20 corresponds to the voltage applied from the IC chip 38 between each pixel electrode 11 and the data line 27 opposed thereto. The orientation direction changes. As shown in FIG. 2, each of the regions (hereinafter referred to as “sub-pixels”) Gs in which the orientation direction changes is assigned one of red, green, and blue.

  On the plate surface of the second substrate 20 facing the liquid crystal 35, the base layer 21, the reflective layer 22, the color filter 24, and the insulating layer 26 are laminated in this order from the second substrate 20 side. The data line 27 and the alignment film 28 described above are formed on the surface of the insulating layer 26. The color filter 24 is a resin layer provided corresponding to each sub-pixel Gs, and is colored in the color of each sub-pixel Gs by a pigment or a dye. The sub-pixel Gs corresponding to the three color filters 24 of red, green and blue constitutes a pixel which is the minimum unit of the display image. In addition, a light shielding layer 25 is formed in the gap between the color filters 24 of each color (that is, the gap between adjacent subpixels Gs). The light shielding layer 25 is formed of a resin material in which carbon black is dispersed or a metal material having a light shielding property such as chromium, and plays a role of shielding the gap between the sub-pixels Gs. The insulating layer 26 is a film body formed so as to cover the color filter 24 and the light shielding layer 25 with various resin materials such as epoxy and acrylic. The insulating layer 26 has a role of flattening the step between the color filter 24 and the light shielding layer 25 and a role of preventing the pigment and dye of the color filter 24 from leaking into the liquid crystal 35.

  On the other hand, the foundation layer 21 is a film body provided on the plate surface of the second substrate 20 and is made of a photosensitive resin material such as acrylic or epoxy. The underlayer 21 is selectively provided only in the region surrounded by the sealing material 34 on the surface of the second substrate 20 and does not exist in the overhanging portion 20a on which the IC chip 38 is mounted. Here, under the configuration in which the base layer 21 is formed over the entire surface of the second substrate 20 including the overhanging portion 20a (that is, the configuration in which the IC chip 38 is mounted on the surface of the base layer 21), the IC chip 38 is provided. There is a problem that the base layer 21 easily peels off from the second substrate 20 together with the IC chip 38 when an external force is applied. On the other hand, as in the present embodiment, the base layer 21 is completely removed from the overhanging portion 20a (that is, a configuration in which the IC chip 38 is mounted on the second substrate 20 without the base layer 21). According to this, there is an advantage that such a problem can be avoided.

  As shown in FIGS. 1 and 2, an opening 211 that penetrates the base layer 21 in the thickness direction is provided in a portion of the base layer 21 corresponding to the vicinity of the center of each sub-pixel Gs. Yes. On the other hand, the reflective layer 22 is a thin film formed on the surface of the base layer 21 by a material having light reflectivity such as a single metal such as aluminum or silver or an alloy containing these metals as a main component. The light-transmitting portion 221 is opened to correspond to the opening 211. Accordingly, a part of each color filter 24 laminated on the base layer 21 and the reflective layer 22 reaches the surface of the second substrate 20 through the light transmitting part 221 of the reflective layer 22 and the opening 211 of the base layer 21. With the configuration described above, the light emitted from the backlight unit that has entered the second substrate 20 from the back side of the liquid crystal display device 100 is transmitted through the opening 211 of the base layer 21 and the light transmitting portion 221 of the reflective layer 22. Through the color filter 24 and the liquid crystal 35, and further through the first substrate 10 to be emitted to the observation side. In this way, transmissive display is realized by the transmitted light from the back side of the liquid crystal display device 100 to the observation side. On the other hand, outside light such as room illumination light and sunlight incident on the first substrate 10 from the observation side of the liquid crystal display device 100 passes through the liquid crystal 35 and the color filter 24 and reaches the surface of the reflective layer 22. The light is reflected from the surface and emitted from the first substrate 10 to the observation side. Thus, the reflective display is realized by the light emitted to the observation side after being reflected by the reflective layer 22.

  Here, if the surface of the reflective layer 22 is a perfect plane, the incident light from the observation side with respect to the liquid crystal display device 100 is specularly reflected on the surface of the reflective layer 22. There may be a problem that a background image opposite to the image appears in the display image. In order to solve this problem, a scattering structure for appropriately scattering the reflected light is formed on the surface of the reflective layer 22 in the present embodiment. More specifically, the surface of the base layer 21 is a rough surface having a number of fine protrusions (convex portions) or depressions (concave portions), and the surface of the reflective layer 22 formed in a thin film shape on the rough surface. In the figure, fine undulations (that is, scattering structures) reflecting the rough surface of the underlayer 21 appear. FIG. 3 is an enlarged perspective view showing the surface shape of the foundation layer 21 in the present embodiment. As shown in the figure, the surface of the base layer 21 is a rough surface on which a number of fine protrusions 213 are formed. Alternatively, if the plane including the tops of these protrusions 213 is used as a reference, the surface of the base layer 21 can be regarded as a rough surface on which a large number of fine depressions 214 are formed. FIG. 4 is an enlarged cross-sectional view showing the protrusion 213 of the base layer 21. As shown in the figure, when the distance from the top of the protrusion 213 to the bottom of the depression 214 is the height H of the protrusion 213 (or the depth of the depression 214), the height H of each protrusion 213 is the base layer 21. Is less than the thickness T (the distance between the contact surface with the second substrate 20 and the top of the protrusion 213). That is, the depth of the depression 214 on the surface of the foundation layer 21 is smaller than the thickness T of the foundation layer 21, and thus each depression 214 does not penetrate the foundation layer 21. Thus, the depth of the depression 214 on the surface of the base layer 21 is selected so that the second substrate 20 is not exposed at the bottom of the depression 214.

  As shown in FIGS. 3 and 4, a depression (concave portion) 213 a is formed in the vicinity of the top of each protrusion 213. The depth D of each recess 213a is smaller than the height H of the protrusion 213 (or the depth of the recess 214). Since the surface of the base layer 21 in this embodiment is such a rough surface, the surface of the reflective layer 22 formed on the surface has a depression at the top as shown in FIG. A large number of fine protrusions are formed. Here, if the top of each protrusion constituting the scattering structure of the reflective layer 22 is a flat surface, the incident light from the observation side is specularly reflected on the flat surface, so that the reflection of the background is reflected. A sufficient light scattering effect to avoid it is not always obtained. On the other hand, according to the scattering structure according to the present embodiment shown in FIGS. 3 and 4, the reflected light from the reflection layer 22 can be scattered even at the top of each protrusion, so that the reflection of the background is completely achieved. A good light scattering effect that can be avoided is obtained.

<A-2: Manufacturing Method of Liquid Crystal Display Device 100>
Next, a method for manufacturing the liquid crystal display device 100 according to the present embodiment will be described with particular attention paid to the step of forming the base layer 21 and the reflective layer 22 on the second substrate 20. FIG. 5 is a process diagram (corresponding to the cross section shown in FIG. 1) showing the configuration of elements on the second substrate 20 in each manufacturing process.

  First, as shown in FIG. 5A, a film body 51 to be the base layer 21 is formed on the plate surface on the second substrate 20. The film body 51 is obtained by applying a positive resin material having photosensitivity on the second substrate 20 by a method such as a spin coat method. Next, the film body 51 is dried in a reduced pressure environment and then heated (pre-baked) at a temperature in the range of 85 ° C. to 105 ° C.

  Thereafter, as shown in FIG. 5B, the film body 51 is exposed through a mask (hereinafter referred to as “exposure mask”) 7a. More specifically, after the exposure mask 7a is arranged with a gap (proximity gap) of about 60 μm from the surface of the film body 51, the light emitted from the light source (for example, i-line) to the film body 51 ) Is irradiated. As shown in FIG. 5B, in the present embodiment, a region (that is, the sealing material 34) around the region (hereinafter referred to as “processed region”) 511 of the film body 51 to be left as a base layer. 513, a region 515 corresponding to the opening 211 of the base layer 21, and a region to be a depression 214 on the surface of the base layer 21 in the processed region 511. Are exposed together. Here, FIG. 6 is a diagram showing a portion that undergoes photolysis by this exposure. In the figure, the vicinity of the boundary between the work area 511 and the peripheral area 513 is shown enlarged, and the hatched area corresponds to a portion photodecomposed by exposure. As shown in FIG. 5 and FIG. 6, in this embodiment, the film body 51 is photodegraded over the entire thickness direction in the peripheral region 513 and the region 515 corresponding to the opening 211, while the underlayer 21. In the region 517 to be the depression 214, only a part in the thickness direction of the film body 51 is photodecomposed. The specific configuration of the exposure mask 7a used in this exposure step will be described in detail later.

  Next, the film body 51 is developed. By this development, as shown in FIG. 5C, the portion of the film body 51 that has been photolyzed by exposure is selectively removed. Subsequently, the film body 51 is heated (melt-baked) at a temperature in the range of 120 ° C. to 130 ° C. By this step, only the surface layer portion of the film body 51 is partially melted, and the uneven corners appearing on the surface of the film body 51 by development are rounded. Thereafter, the film body 51 is baked (post-baked) at a temperature of about 220 ° C. Through these steps, as shown in FIG. 5D, the surface shape of the entire film body 51 is determined, and the underlayer 21 is obtained. Here, the heating of the film body 51 after the development is performed in two stages. If the film body 51 after the development is immediately heated to a temperature of about 220 ° C., the unevenness on the surface thereof is excessively melted. This is because the surface has many flat portions, and as a result, the light scattering effect is impaired. That is, it can be said that the step of heating the film body 51 in the range of 120 ° C. to 130 ° C. prior to post-baking is a process for maintaining and stabilizing the surface shape of the film body 51 in an intended shape.

  Next, as illustrated in FIG. 5E, the reflective layer 22 having the light transmitting portion 221 is formed on the surface of the base layer 21. That is, a thin film made of a light-reflective material is formed on the surface of the base layer 21 by a film formation method such as sputtering, and the thin film is patterned by a photolithography technique and an etching technique to obtain the reflection layer 22. . As described above, a scattering structure reflecting the rough surface of the base layer 21 is formed on the surface of the reflective layer 22.

  Subsequently, the color filter 24 and the light shielding layer 25 are formed, and the insulating layer 26 is formed so as to cover them. Further, after the data line 27 is formed on the surface of the insulating layer 26, an alignment film 28 is formed by an organic thin film such as polyimide and subjected to a rubbing process. Meanwhile, each element on the first substrate 10 can be manufactured by various known techniques. Next, the first substrate 10 and the second substrate 20 that have undergone the above-described processes are bonded together with the sealing material 34 in a state where the alignment films 14 and 28 face each other. Further, a liquid crystal 35 is sealed in a space surrounded by both substrates and the sealing material 34, and this space is sealed with a sealing material (not shown). Thereafter, the retardation plates 311 and 321 and the polarizing plates 312 and 322 are attached to the first substrate 10 and the second substrate 20, respectively, and the IC chip 38 is mounted on the overhanging portion 20a of the second substrate 20, The liquid crystal display device 100 shown in FIG. 1 is obtained.

<A-3: Configuration of Exposure Mask 7a>
Next, the configuration of the exposure mask 7a used in the exposure step (hereinafter simply referred to as “exposure step”) in FIG. FIG. 7 is a plan view showing the structure of the exposure mask 7a. As shown in the figure, the exposure mask 7a in the present embodiment is divided into a first region 71 and a second region 72 in plan view. Among these, the first region 71 is a region that is opposed to the peripheral region 513 (that is, a region that is removed by development as not constituting the underlayer 21) in the exposure process. On the other hand, the second region 72 is a region that faces the processing region 511 of the film body 51 in the exposure process. The second region 72 includes a large number of dot-like regions (hereinafter referred to as “dot regions”) 721 that are distributed at random positions and a region corresponding to the opening 211 of the base layer 21 (hereinafter referred to as “opening formation”). 724) (referred to as “region”). Each dot region 721 in the present embodiment is a region corresponding to the protrusion 213 on the surface of the base layer 21.

  Next, FIG. 8 is a sectional view showing the structure of the exposure mask 7a. Focusing on the cross-sectional structure as shown in the figure, the exposure mask 7 a has a base material 70, and a light shielding portion 84 and a semi-transmissive portion 86 formed on the plate surface of the base material 70. Among these, the base material 70 is a plate-like member that transmits almost all of the irradiation light from the light source. That is, the light transmittance of the base material 70 itself with respect to the light emitted from the light source in the exposure processing is about 100%. On the other hand, the light-shielding portion 84 is a film body that shields (absorbs or reflects) substantially all of the light emitted from the light source, and is formed of a light-shielding material such as chromium. On the other hand, the semi-transmissive portion 86 is a portion that transmits the irradiation light from the light source with a light transmittance lower than that of the base material 70. In other words, the semi-transmissive portion 86 transmits only a part of the light emitted from the light source, while the other part is shielded (absorbed or reflected). As a specific form of the semi-transmissive portion 86, any of the following halftone and gray tone can be adopted. However, the semi-transmissive portion in the present invention is not limited to the configuration shown below.

The halftone is made of a light-shielding material such as chromium oxide (Cr ₂ O ₃ ) or molybdenum silicide (MoSi or MoSi ₂ ). By forming these materials on the base material 70 in a thin film shape, only a part of the irradiation light from the light source is transmitted and reaches the film body 51, while the other part is shielded.

  On the other hand, in gray tone, a large number of fine light-shielding portions (hereinafter referred to as “micro-light-shielding portions”) and a large number of fine light-transmitting portions (hereinafter referred to as “micro-light-transmitting portions”) are arranged on the substrate 70 in a planar shape. Do it. Among these, each minute light-shielding part is a part formed in the same process as the light-shielding part 84, and shields substantially all of the irradiation light from the light source. On the other hand, each micro light-transmitting portion is a portion where the base material 70 is exposed (that is, a portion where no light-shielding member is provided), and therefore transmits almost all of the irradiation light from the light source. Since each of these regions is arranged in a plane, a part of the irradiation light from the light source passes through the minute light transmitting part and reaches the film body 51, while the other part is caused by the minute light shielding part. Shaded. In the semi-transmissive portion 86 that employs this gray tone, the minute light-shielding portion and the minute light-transmissive portion are in the plane of the semi-transmissive portion 86 so that the intensity of the transmitted light is substantially uniform over the surface of the semi-transmissive portion 86. It is desirable to disperse and arrange in FIG. FIG. 9 and FIG. 10 are plan views showing desirable arrangement modes of the minute light-shielding portions and the minute light-transmitting portions.

  In FIG. 9, the substantially square-shaped micro light-shielding portions 861 and the substantially square-shaped micro light-transmitting portions 862 are staggered in the x and y directions orthogonal to each other (that is, between the micro light-shielding portions 861 or the micro-transparent portions). A mode in which the light portions 862 are arranged so that the light portions 862 are not adjacent to each other is illustrated. Here, depending on the length of each side of each micro light shielding portion 861 and each micro light transmitting portion 862, the light transmitted through the micro light transmitting portion 862 is diffracted at the periphery of the micro light shielding portion 861 and interferes with each other. As a result, it is possible to prevent the intended region 511 from being irradiated with the desired amount of light. In order to solve this problem, the length L of each side of each micro light-shielding portion 861 and each micro light-transmissive portion 862 is preferably 1.0 μm or more and 2.0 μm or less, and is preferably 1.5 μm or less. Further preferred.

  On the other hand, in FIG. 10, linear micro light-shielding portions 865 extending in the y direction and linear micro light-transmitting portions 866 extending in the y direction are alternately arranged in the x direction orthogonal to the y direction. In other words, a mode in which the micro light shielding portions 865 or the micro light transmitting portions 866 are not adjacent to each other is illustrated. Even in this mode, from the viewpoint of preventing problems due to interference of diffracted light, the width W of each micro light-shielding portion 865 and each micro light-transmissive portion 866 is preferably 1.0 μm or more and 2.0 μm or less. More preferably, it is 1.5 μm or less.

  Of the two types of semi-transmissive portions 86 described above, the semi-transmissive portion 86 employing a halftone has a light transmitted through the semi-transmissive portion 86 as compared with the semi-transmissive portion 86 employing a gray tone. There is an advantage that the diffraction of the above cannot be generated in principle. However, the semi-transmissive portion 86 in which halftone is adopted is formed in a separate process from the light shielding portion 84 of the exposure mask 7a. On the other hand, according to the semi-transmission part 86 employing the gray tone, there is an advantage that the semi-transmission part 86 can be formed in the same process as the light shielding part 84 of the exposure mask 7a.

  In FIG. 7, the hatched area indicates that the light shielding portion 84 is provided, and the hatched area indicates that the semi-transmissive portion 86 is provided. The hatched area indicates that neither the light-shielding portion 84 nor the semi-transmissive portion 86 is provided (the same applies to FIGS. 13 to 15 described below). As shown in FIG. 7, neither the light shielding part 84 nor the semi-transmissive part 86 is provided in the first region 71 of the exposure mask 7 a according to this embodiment. That is, the first region 71 is a region where only the base material 70 exists, and functions as a light transmitting part 81 that transmits light from the light source toward the peripheral region 513. Similarly to the first area 71, the opening formation area 724 is an area of only the base material 70 and functions as the light transmitting portion 81. Therefore, as shown in FIG. 6, the peripheral region 513 of the film body 51 to which the transmitted light of the first region 71 reaches and the region 515 of the film body 51 to which the transmitted light of the opening formation region 724 reach have the thickness. Photolysis will occur over the entire direction. On the other hand, as shown in FIG. 7, a semi-transmissive portion 86 is provided in a region excluding each dot region 721 and the opening formation region 724 in the second region 72. Accordingly, only a part of the light traveling from the light source toward the processing region 511 of the film body 51 toward the region to be the depression 214 in the base layer 21 reaches the surface of the film body 51. Therefore, as shown in FIG. 6, only a part in the thickness direction of the film body 51 to be the depression 214 of the base layer 21 is photodecomposed.

  Further, as shown in FIG. 7, each dot region 721 of the second region 72 is covered with a light shielding portion 84. Therefore, a region of the processing region 511 that is prevented from being irradiated with light by each dot region 721 becomes a protrusion 213 of the base layer 21 without being removed by development. FIG. 11 is an enlarged plan view showing one dot region 721. As shown in the figure, the shape of each dot region 721 in the present embodiment is a substantially polygon (here, a hexagon), and therefore the planar shape of each light shielding portion 84 is also a substantially polygon. Here, if the diameter d of the circumscribed circle C of each dot area 721 shown in FIG. 11 is too small, it may be difficult to accurately control the area actually exposed in the exposure process. On the other hand, if the diameter d of the circumscribed circle C of each dot region 721 is too large, the top of the protrusion 213 of the base layer 21 becomes a flat surface, and the light scattering effect by the reflective layer 22 formed on the surface is reduced. To do. Therefore, the diameter d of the circumscribed circle C of each dot region 721 is preferably set to 8.0 μm to 11.0 μm, and more preferably set to 9.0 μm to 10.0 μm.

  Here, the ratio of the total area of the plurality of dot regions 721 in the area of the entire plate surface of the exposure mask 7a (that is, the total area of the first region 71 and the second region 72) is selected as follows. It is desirable that That is, since the dot region 721 in the present embodiment corresponds to the region of the film body 51 that becomes the protrusion 213 in the base layer 21, the proportion of the dot region 721 in the entire plate surface of the exposure mask 7a is too small. In this case, the area of the protrusion 213 occupying the surface of the base layer 21 is reduced, the flat portion is increased, and the light scattering effect by the reflective layer 22 is reduced. On the other hand, when the ratio of the dot region 721 to the entire plate surface of the exposure mask 7a is too large, the flat portion increases as a result of the area of the projection 213 occupying the surface of the base layer 21 increasing. The light scattering effect by the reflective layer 22 is reduced. Therefore, in order to obtain a good light scattering effect by the reflective layer 22, it is desirable that the ratio of the total area of the dot regions 721 in the entire area of the exposure mask 7a is 30% or more and 60% or less.

  On the other hand, as shown in FIG. 11, a peripheral translucent portion 88 is provided around each dot region 721 so as to be in contact with the entire periphery of the dot region 721 (the entire periphery of the light shielding portion 84). Similar to the light transmitting portion 81, the peripheral light transmitting portion 88 is a portion where neither the light shielding portion 84 nor the semi-transmissive portion 86 is provided (that is, the portion where the base material 70 is exposed). The incident light passes through the peripheral light transmitting portion 88 with the same light transmittance as the light transmitting portion 81 (about 100%) and reaches the film body 51. FIG. 12 is a diagram showing a state of transmitted light in the vicinity of each dot region 721. As shown in the figure, the light transmitted through the peripheral light transmitting portion 88 provided around one dot region 721 is diffracted at the periphery of the light shielding portion 84 covering the dot region 721 and then the surface of the film body 51. To. Here, since the optical path length of each diffracted light Li passing through the peripheral light transmitting portion 88 and reaching the surface of the film body 51 is equal, the phase difference of the diffracted light Li on the surface of the film body 51 becomes zero, and each diffracted light Li strengthens each other on the surface of the film body 51. As a result, a region 518 corresponding to the top of the protrusion 213 in the film body 51 is partially photodegraded and then developed, whereby a depression at the top of the protrusion 213 as shown in FIGS. 3 and 4 is obtained. 213a.

  As described above, the exposure mask 7a according to this embodiment has the semi-transmissive portion 86 so as to overlap the region to be the depression 214 in the base layer 21 in the region to be processed 511. Only a part in the thickness direction is photodegraded. Therefore, since the surface of the second substrate 20 is not exposed at the bottom of the recess 214 of the base layer 21, the reflective layer 22 provided on the surface of the base layer 21 provides a good light scattering effect. . Moreover, according to this exposure mask 7a, the exposure for removing the periphery of the region to be processed 511 and the partial exposure of the region corresponding to the depression 214 of the underlayer 21 are performed in a common process. Therefore, the manufacturing process can be simplified and the manufacturing cost can be reduced as compared with the conventional technique.

<B: Second Embodiment>
In the first embodiment, the configuration in which the protrusions 213 of the base layer 21 are formed so as to correspond to the dot regions 721 of the exposure mask 7a is illustrated. On the other hand, in this embodiment, the depression 214 of the base layer 21 is formed so as to correspond to the dot region 721 of the exposure mask 7b. The exposure mask 7b according to the present embodiment is used for exposing the positive type film body 51 as in the first embodiment. In addition, in the present embodiment, the description common to the first embodiment will be omitted as appropriate.

  FIG. 13 is a plan view showing the configuration of the exposure mask 7b according to this embodiment. As shown in the figure, the exposure mask 7b is common to the exposure mask 7a according to the above embodiment in that the first region 71 and the opening formation region 724 are the light transmitting portion 81, but the light shielding portion. The positional relationship between 84 and the semi-transmissive portion 86 is reverse to that of the exposure mask 7a. That is, the semi-transmissive portion 86 is provided in a region corresponding to the plurality of dot regions 721 in the second region 72 of the exposure mask 7b, and the light shielding portion 84 is provided in a region other than the dot region 721. In the exposure mask 7b, a peripheral light transmitting portion 88 is provided at the periphery of the dot region 721 (periphery of the semi-transmissive portion 86) as in the first embodiment.

  The manufacturing method of the liquid crystal display device 100 according to the present embodiment is the same as the manufacturing method described in the above embodiment, except that the exposure mask 7b is used in the exposure step shown in FIG. In the exposure step shown in FIG. 5B, as in the first embodiment, the peripheral region 513 and the region 515 of the film body 51 are in the thickness direction by the light transmitted through the first region 71 of the exposure mask 7b. All of the photodecomposes. In addition, light that has passed through the semi-transmissive portion 86 provided in the dot region 721 of the exposure mask 7b is irradiated to the region of the processed region 511 of the film body 51 that becomes the depression 214 of the base layer 21, and the thickness thereof is irradiated. Photolytic over part of direction. On the other hand, since the light which goes to the area | region which overlaps with areas other than the dot area | region 721 among the process area | regions 511 is interrupted | blocked by the light-shielding part 84, this area | region is not removed by development. Therefore, the surface of the base layer 21 obtained through the exposure process using the exposure mask 7b is a rough surface formed by dispersing a large number of depressions 214 at random positions. This embodiment can provide the same effects as those of the first embodiment.

<C: Third Embodiment>
In the said 1st and 2nd embodiment, the case where the base layer 21 was formed by processing the film body 51 which consists of a positive photosensitive material was illustrated. On the other hand, in this embodiment, the film body 51 is formed of a negative photosensitive material. Note that, in the present embodiment, the description of matters common to the first embodiment is omitted as appropriate.

  FIG. 14 is a plan view showing the configuration of the exposure mask 7c according to this embodiment. In this embodiment, since the film body 51 made of a negative photosensitive material is exposed, the exposure mask 7c has a positional relationship between the light shielding portion 84 and the light transmitting portion 81 as shown in FIG. This is opposite to the exposure mask 7a (see FIG. 7) shown in the embodiment. That is, the light shielding portion 84 is formed in the first region 71 and the opening formation region 724 of the exposure mask 7 c, while each dot region 721 included in the second region 72 is a light transmitting portion 81. The semi-transmissive portion 86 is formed in the second area 72 other than the dot areas 721, similar to the exposure mask 7a according to the first embodiment.

  In the method of manufacturing the liquid crystal display device 100 according to the present embodiment, the film body 51 is formed of a negative photosensitive material in the step shown in FIG. 5A, and the step shown in FIG. The manufacturing method shown in FIG. 1 is the same as that of the first embodiment except that the exposure mask 7c is used. In the exposure process shown in FIG. 5B, since the light directed to the peripheral region 513 and the region 515 of the film body 51 is blocked by the light blocking portion 84, these regions are removed by development. On the other hand, the portion of the film body 51 that is irradiated with the light that has passed through each dot region 721 of the exposure mask 7c is exposed throughout the thickness direction and is insoluble in the developer. Therefore, a region that overlaps each dot region 721 in the processing region 511 of the film body 51 becomes a protrusion 213 on the surface of the base layer 21. On the other hand, the light transmitted through the semi-transmissive portion 86 in the area other than the dot areas 721 of the second area 72 in the exposure mask 7c reaches the film body 51 and exposes only a part in the thickness direction. Therefore, only a part in the thickness direction is removed by this development, and this portion becomes a recess 214 of the base layer 21. This embodiment can provide the same effects as those of the first embodiment.

<D: Fourth Embodiment>
In the said 3rd Embodiment, the structure in which the processus | protrusion 213 of the base layer 21 was formed corresponding to the dot area | region 721 of the mask 7c for exposure was illustrated. On the other hand, in this embodiment, the depression 214 of the underlayer 21 is formed so as to correspond to the dot region 721 of the exposure mask 7d. The underlayer 21 according to the present embodiment is formed of a negative photosensitive material as in the third embodiment. That is, the present embodiment is common to the second embodiment except for the type of photosensitive material constituting the film body 51 and the configuration of the exposure mask 7d resulting therefrom.

  FIG. 15 is a plan view showing the configuration of the exposure mask 7d according to this embodiment. As shown in the figure, the exposure mask 7d has the positional relationship between the light shielding portion 84 and the light transmitting portion 81 reversed from the exposure mask 7b shown in the second embodiment. That is, the light shielding portion 84 is formed in the first region 71 and the opening formation region 724 in the exposure mask 7d, while the region other than the dot regions 721 in the second region 72 is the light transmitting portion 81. Yes. The point that the semi-transmissive portion 86 is formed in each dot region 721 in the second region 72 is the same as the exposure mask 7b according to the second embodiment.

  In the method of manufacturing the liquid crystal display device 100 according to the present embodiment, the film body 51 is formed of a negative photosensitive material in the step shown in FIG. 5A, and the step shown in FIG. The manufacturing method is the same as that of the first embodiment except that the exposure mask 7d is used. In the exposure step shown in FIG. 5B, the light directed to the peripheral region 513 and the region 515 of the film body 51 is blocked by the light shielding portion 84, and thus this region is removed by development. On the other hand, the portion of the film body 51 that is irradiated with the light transmitted through the region other than the dot regions 721 of the exposure mask 7d is exposed throughout the thickness direction and is insoluble in the developer. Further, the light transmitted through the semi-transmissive portion 86 in each dot region 721 of the second region 72 in the exposure mask 7d reaches the film body 51 and exposes only a part in the thickness direction. Therefore, only a part in the thickness direction is removed by this development, and this portion becomes a recess 214 of the base layer 21. This embodiment can provide the same effects as those of the first embodiment.

<E: Modification>
The embodiment described above is merely an example. Various modifications can be made to this embodiment without departing from the spirit of the present invention. Specifically, the following modifications can be considered.

(1) In each of the above embodiments, the configuration in which the opening 211 is provided in the base layer 21 so as to correspond to each pixel is illustrated. However, as shown in FIG. 16, the opening 211 is provided in the base layer 21. Configurations that are not possible may also be employed. However, in the configuration shown in FIG. 16, part of the light traveling from the second substrate 20 side to the first substrate 10 side is absorbed by the base layer 21 in the transmissive display. Therefore, from the viewpoint of suppressing the loss of the amount of light used for the transmissive display, a configuration in which the opening 211 is provided in the base layer 21 as in the above embodiments is desirable. In each of the above embodiments, the so-called transflective liquid crystal display device 100 capable of both reflective display and transmissive display has been exemplified. However, the present invention also applies to the liquid crystal display device 100 capable of only reflective display. Can be applied. In this case, the opening 211 of the reflective layer 22 and the light transmitting part 221 of the reflective layer 22 are not provided. Accordingly, the opening formation region 724 is not provided in the exposure mask 7 (7a, 7b, 7c, and 7d).

(2) In each of the above embodiments, the light-shielding portion 84 is configured by a single layer. However, the light-shielding portion 84 is formed by laminating a light-shielding layer such as chrome and a semi-transmissive portion 86 employing a halftone. Also good. According to this configuration, the light shielding performance by the light shielding unit 84 can be enhanced.

(3) In each of the above embodiments, the dot area 721 of the exposure mask 7 (7a, 7b, 7c and 7d) is a polygon, but the planar shape of each dot area 721 is arbitrary, for example, other than a regular polygon It may be a polygon or a circle. In addition, when the planar shape of the dot area | region 721 is made into a polygon, it is desirable for each of the vertex angle to be an obtuse angle. This is because if the apex angle of the dot region 721 is an acute angle, light is diffracted in the vicinity of the dot region 721, and the intended exposure may be hindered.

(4) In the first and second embodiments, the configuration in which the peripheral light-transmitting portion 88 is provided so as to contact the entire periphery of each dot region 721 has been illustrated. However, as shown in FIG. A configuration may also be employed in which 88 is provided so as to be in partial contact with the periphery of each dot region 721 (here, the light shielding portion 84). In the figure, a configuration in which the peripheral translucent portion 88 is provided along only three sides that are not adjacent to each other among the sides of the substantially hexagonal dot region 721 is illustrated. In the configuration shown in FIG. 11, since the amount of light that passes through the peripheral light transmitting portion 88 over the entire periphery of the dot region 721 and reaches the region 518 of the film body 51 is large, the depression 213a at the top of the protrusion 213 is formed. It may be too deep. On the other hand, according to the configuration according to the present modification, the amount of diffracted light that passes through the peripheral light transmitting portion 88 and reaches the region 518 of the film body 51 can be reduced as compared with the case of FIG. Can be prevented from becoming too deep. Thus, it is desirable that the shape of the peripheral translucent portion 88 is selected so that the depth of the recess 213a is optimal.

(5) Although the liquid crystal display device has been exemplified in each of the above embodiments, the present invention can be applied to other electro-optical devices. That is, the present invention can be applied to any device that displays an image using an electro-optical material that converts an electrical action of supplying an image signal into an optical action such as a change in luminance and light transmittance. For example, an electrophoretic display device using a microcapsule including a colored liquid and white particles dispersed in the liquid as an electro-optical material, and a twist ball that is separately applied in different colors for different regions of polarity. The present invention can be applied to various electro-optical devices such as a twist ball display used as an electro-optical material or a toner display using black toner as an electro-optical material. It can be said that the electro-optical device substrate according to the present invention is particularly suitable for an electro-optical material that displays an image using an electro-optical material that itself does not emit light, as exemplified above. However, the present invention can also be applied to an electro-optical device using an electro-optical material that emits light (that is, a self-luminous electro-optical material). For example, when the electro-optic device substrate according to the present invention is provided on the back side of a self-luminous electro-optic material, a bright display is realized by reflecting light emitted from the electro-optic material to the back side to the observation side. Is done. The electro-optical device using the self-luminous electro-optical material includes a display device using an organic light emitting diode (OLED) element such as an organic EL or a light-emitting polymer as an electro-optical material, or a high-pressure gas such as helium or neon. For example, a plasma display panel (PDP) using a phosphor as an electro-optical material, and a field emission display (FED) using a phosphor as an electro-optical material.

<F: Electronic equipment>
Next, an electronic apparatus including the electro-optical device according to the invention as a display device will be described. FIG. 18 is a perspective view showing a configuration of a mobile phone using the liquid crystal display device 100 according to each of the above embodiments. As shown in this figure, the mobile phone 1200 includes the liquid crystal display device 100 described above together with a plurality of operation buttons 1202, an earpiece 1204, and a mouthpiece 1206.

  FIG. 19 is a perspective view showing a configuration of a digital still camera in which the liquid crystal display device 100 according to each of the above embodiments is applied to a viewfinder. The liquid crystal display device 100 according to each of the above embodiments is provided on the back surface of the main body 1302 in the digital still camera 1300. Since the liquid crystal display device 100 performs display based on the imaging signal, it functions as a finder for displaying the subject. A light receiving unit 1304 including an optical lens and a CCD is provided on the front side of the main body 1302 (the back side in FIG. 19). When the photographer confirms the subject image displayed on the liquid crystal display device 100 and presses the shutter button 1306, the CCD image pickup signal at that time is transferred and stored in the memory of the circuit board 1308. Further, in the digital still camera 1300, a video signal output terminal 1312 for external display and an input / output terminal 1314 for data communication are provided on the side surface of the case 1302.

  Note that examples of electronic equipment in which the electro-optical device according to the present invention can be used as a display device include a notebook computer, a liquid crystal television, a mobile phone shown in FIG. 18 and a digital still camera shown in FIG. Examples include a viewfinder type (or monitor direct view type) video recorder, a car navigation device, a pager, an electronic notebook, a calculator, a word processor, a workstation, a videophone, a POS terminal, and a device equipped with a touch panel.

It is sectional drawing which shows the structure of the liquid crystal display device which concerns on 1st Embodiment of this invention. It is a perspective view which expands and shows the structure of the principal part of a liquid crystal display device. It is a perspective view which shows the surface shape of a base layer among liquid crystal display devices. It is sectional drawing which expands and shows the protrusion in a base layer. It is sectional drawing which shows the manufacturing process of each element on a 2nd board | substrate among liquid crystal display devices. It is sectional drawing which shows the part photodecomposed in an exposure process among film bodies. It is a top view which shows the structure of the mask for exposure. It is sectional drawing which shows the structure of the mask for exposure. It is a top view which shows the specific structure of the semi-transmission part which employ | adopted the gray tone. It is a top view which shows the specific structure of the semi-transmission part which employ | adopted the gray tone. It is a top view which expands and shows the dot area | region of the mask for exposure. It is sectional drawing which shows the path | route of the light emitted from the light source and having reached the vicinity of the dot area | region. It is a top view which shows the structure of the mask for exposure which concerns on 2nd Embodiment of this invention. It is a top view which shows the structure of the mask for exposure which concerns on 3rd Embodiment of this invention. It is a top view which shows the structure of the mask for exposure which concerns on 4th Embodiment of this invention. It is sectional drawing which shows the structure of the liquid crystal display device which concerns on a modification. It is a top view which expands and shows the dot area | region of the mask for exposure which concerns on a modification. It is a perspective view which shows the structure of the mobile telephone which is an example of the electronic device which concerns on this invention. 1 is a perspective view illustrating a configuration of a digital still camera which is an example of an electronic apparatus according to the invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Liquid crystal display device, 10 ... 1st board | substrate, 11 ... Pixel electrode, 12 ... Scanning line, 13 ... TFD element, 14 ... Alignment film, 20 ... 2nd board | substrate, 21 ... Underlayer , 211... Opening, 213... Projection, 213 a .. depression on top of projection, 214... Depression, 22 .. reflective layer, 221 .. translucent portion, 24 .. color filter, 25. 26, insulating layer, 27 ... data line, 34 ... sealing material, 35 ... liquid crystal, 38 ... IC chip, 51 ... film body, 511 ... processed area, 513 ... peripheral area, 515... Region of the film body that serves as an opening of the underlayer 517... Region of the film body that serves as a depression of the underlayer, 7 a, 7 b, 7 c, 7 d. 72... 2nd region, 721... Dot region, 81. ...... semi-transmission part, 861,865 ...... fine light-shielding portions, 862,866 ...... minute light transmitting portions, 88 ...... peripheral transparent portion.

Claims (21)

In the mask used for the exposure process for making the work area of the film body a rough surface,
A first region having a light transmitting portion that transmits light toward the periphery of the region to be processed;
A semi-transmissive portion that has a plurality of dot regions each provided with a light shielding portion that blocks light traveling toward the processing region, and transmits light traveling toward the processing region with a light transmittance lower than that of the light transmitting portion. And a second region provided in a region other than each of the dot regions. In the mask used for the exposure process for making the work area of the film body a rough surface,
A first region having a light transmitting portion that transmits light toward the periphery of the region to be processed;
A light-shielding portion that has a plurality of dot regions each provided with a semi-transmissive portion that transmits light toward the processing region at a light transmittance lower than that of the light-transmitting portion, and blocks light traveling toward the processing region And a second region provided in a region other than each of the dot regions. 3. The exposure mask according to claim 1, further comprising a peripheral translucent portion that is provided in a region in contact with the entire periphery of each dot region and transmits light at substantially the same light transmittance as the translucent portion. 3. The exposure mask according to claim 1, further comprising a peripheral light-transmitting portion that is provided in a region in contact with a part of the periphery of each dot region and transmits light at substantially the same light transmittance as the light-transmitting portion. . In the mask used for the exposure process for making the work area of the film body a rough surface,
A first region provided with a light-shielding part that shields light toward the periphery of the region to be processed;
The light-transmitting portion that transmits light toward the processing region has a plurality of dot regions provided respectively, and transmits light toward the processing region with a light transmittance lower than that of each light-transmitting portion. An exposure mask having a semi-transmissive portion and a second region provided in a region other than each of the dot regions. In the mask used for the exposure process for making the work area of the film body a rough surface,
A first region provided with a light-shielding part that shields light toward the periphery of the region to be processed;
A plurality of dot regions each having a semi-transmission portion that transmits light toward the region to be processed is provided, and a light-transmitting portion that transmits light toward the region to be processed is provided in a region other than each dot region. And a second region having a light transmittance of the semi-transmissive portion lower than a light transmittance of the light-transmissive portion. The exposure mask according to any one of claims 1 to 6, wherein the light transmittance of the semi-transmissive portion is 10% or more and 40% or less. The exposure mask according to any one of claims 1 to 7, wherein the semi-transmissive portion includes a plurality of minute light shielding portions that block light and a plurality of minute light transmissive portions that transmit light. The semi-transmissive portion is formed by alternately arranging the micro light-shielding portions and the micro light-transmitting portions across a first direction and a second direction different from the first direction. Exposure mask. The exposure mask according to claim 9, wherein each of the minute light-shielding portions and each of the minute light-transmitting portions has a rectangular shape with each side having a length of 2 μm or less. The semi-transmissive portion is formed by alternately arranging the minute light-shielding portions and the minute light-transmitting portions extending in a first direction in a second direction orthogonal to the first direction. The exposure mask according to 8. The exposure mask according to claim 11, wherein a width of each of the minute light shielding portions and each of the minute light transmitting portions is 2 µm or less. The exposure mask according to any one of claims 1 to 12, wherein a planar shape of the dot region is a polygon, and a circumscribed circle has a diameter of 8 µm or more and 11 µm or less. 14. The exposure mask according to claim 1, wherein a ratio of the area of the plurality of dot regions to a total area of the first region and the second region is 30% or more and 60% or less. In a method for manufacturing a substrate for an electro-optical device comprising a base layer having a rough surface and a reflective layer provided on the rough surface of the base layer,
A film body forming step of forming a film body from a positive photosensitive material;
A step of exposing the film body through an exposure mask, wherein light from a light source directed to one of a region to be a projection on the rough surface and a region to be a depression is blocked by a light shielding portion of the exposure mask. And the exposure process which makes the light act on only a part of the thickness direction of the film body by transmitting the light from the light source which goes to the other of these regions through the semi-transmission part of the exposure mask, and
A development step of developing the film body that has undergone the exposure step to form the underlayer;
And a reflective layer forming step of forming the reflective layer having light reflectivity on the rough surface of the underlayer obtained by the developing step. In the exposure step, the light directed to the region to be the projection of the rough surface is blocked by the light shielding portion, and the light toward the region to be the depression of the rough surface is transmitted by the semi-transmissive portion, while the exposure 16. The light transmitted through the peripheral light-transmitting portion provided around the light-shielding portion in the mask for use is diffracted at the periphery of the light-shielding portion, and this diffracted light is applied to the portion that should be the top of the projection. The manufacturing method of the board | substrate for electro-optical apparatuses of description. In a method for manufacturing a substrate for an electro-optical device comprising a base layer having a rough surface and a reflective layer provided on the rough surface of the base layer,
A film body forming step of forming a film body from a negative photosensitive material;
A step of exposing the film body through an exposure mask, wherein light from a light source directed to one of a region to be a projection on the rough surface and a region to be a depression is passed through a light transmitting portion of the exposure mask. By transmitting the light, the light acts on the entire thickness direction of the film body, and transmits the light from the light source toward the other of these regions through the semi-transmissive portion of the exposure mask. An exposure step of causing the light to act on only a part of the thickness direction of
A development step of developing the film body that has undergone the exposure step to form the underlayer;
And a reflective layer forming step of forming the reflective layer having light reflectivity on the rough surface of the underlayer obtained by the developing step. In a method of manufacturing an electro-optical device including a substrate for an electro-optical device including a base layer having a rough surface and a reflective layer provided on the rough surface of the base layer,
A step of manufacturing a substrate for an electro-optical device by the method according to claim 15;
And a step of disposing an electro-optic material so as to face the reflective layer of the substrate for the electro-optic device. A base layer having a plurality of protrusions each having a depression formed on the top thereof, on the surface;
A substrate for an electro-optical device, comprising: a reflective layer having light reflectivity provided on a surface of the base layer having the plurality of protrusions. A first substrate and a second substrate that face each other and sandwich the electro-optic material;
A base layer having a plurality of protrusions formed on the surface of the second substrate on the surface of the second substrate facing the electro-optic material, each of which has a depression formed on the top,
An electro-optical device comprising: a reflective layer having light reflectivity provided on a surface of the base layer having the plurality of protrusions.   An electronic apparatus comprising the electro-optical device according to claim 20 as a display device.

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