JP2015169904A - Method for manufacturing reflection type display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a reflection type display device capable of significantly suppressing uneven filling of a display medium by preventing an inner edge part of an outer peripheral seal from forming an irregularly corrugated contour in a plan view.SOLUTION: A method for manufacturing a reflection type display device comprises the steps of: forming a partition wall in a display region of one substrate; forming an adhesive layer on the partition wall; arranging a fluid-like display medium on the display region of the one substrate or on a display region of the other substrate; arranging an outer peripheral seal surrounding the fluid-like display medium on the outside of the display region of the one substrate or on the outside of the display region of the other substrate; and mutually bonding the one substrate and the other substrate. In the outer peripheral seal arranging step, the outer peripheral seal is arranged so that the height from the bottom surface to the top surface of the outer peripheral seal becomes higher than the height from the bottom surface of the partition wall to the top surface of the adhesive layer, and less than three times the height from the bottom surface of the partition wall to the top surface of the adhesive layer.

Description

  The present invention relates to a manufacturing method of a reflective display device applied to electronic paper or the like.

  Recently, as a reflective display device, an electrophoretic display device using an electrophoretic material as an electroresponsive material contained in a display medium has been widely used. An electrophoretic display device is a device that displays information by using electrophoretic migration, that is, particle movement, of an electrophoretic body (usually electrophoretic particles) in air or in a solvent. In general, an electrophoretic state is controlled by applying an electric field between two substrates, thereby realizing a desired display. As the electrophoretic body, charged powder as well as charged particles can be used. In that case, the charged powder electrophoreses in the gas.

  In recent years, the electrophoretic display device has attracted attention especially as an electronic paper. When applied as an electronic paper, it is possible to enjoy advantages such as visibility at the printed matter level (easy for eyes), ease of information rewriting, low power consumption, and light weight.

  However, in an electrophoretic display device, display failure, particularly contrast reduction, may occur due to sedimentation or uneven distribution of fluid or powder. In order to prevent this phenomenon, it is used to form partition walls between the upper and lower electrode substrates and divide the migration space of the particles and powder to be electrophoresed, that is, the movement space into minute spaces. This minute space is called a cell or a pixel. In each cell, ink or gas (display medium) containing an electrophoretic body is enclosed. For example, Japanese Unexamined Patent Application Publication No. 2005-202245 discloses a conventional example of such an electrophoretic display device.

  Japanese Patent Application Laid-Open No. 2011-164300 discloses a manufacturing method for manufacturing a display panel as an electrophoretic display device by bonding upper and lower substrates. In addition, in Patent Document 3 (Japanese Patent Laid-Open No. 2012-013790) filed by the present applicant, an electrophoretic display is provided in which an adhesive is applied only on the partition walls partitioning the cells to ensure adhesion between the partition walls and the substrate. An apparatus manufacturing method is disclosed.

  When adhering the top surface of the partition provided on one substrate and the other substrate, it is strongly avoided from the viewpoint of display quality that bubbles enter into each cell formed by the partition. desired. For this reason, the bonding process in which a display medium exceeding the volume of the cell is placed on one of the substrates in advance and the two substrates are bonded (bonded together) while the fluid display medium overflows from the cell. It has been implemented. This point is disclosed in, for example, Patent Document 4 (Japanese Patent No. 2733679).

  In addition to adhering the top surface of the partition provided on one substrate and the other substrate, an outer peripheral seal surrounding the fluid display medium is disposed between the two substrates, and the outer peripheral seal is cured. It is also common to increase the adhesive strength between the two substrates. Further, in the outer peripheral seal arrangement step before the substrate bonding step, the outer peripheral seal is generally arranged at a height of four times or more the height of the partition wall on one substrate or the other substrate. .

  In Patent Document 5 (Japanese Patent Application Laid-Open No. 2011-64789), a second electrophoretic layer is provided as a separator between the display region and the outer peripheral seal in order to prevent the outer peripheral seal from entering the display region. It is disclosed.

JP-A-2005-202245 JP 2011-164300 A JP 2012-013790 A Japanese Patent No. 2733679 JP 2011-066489 A

  However, when the two substrates are bonded while causing the display medium to overflow from the cell, uneven filling of the display medium may occur.

  As a result of intensive studies on this cause, the present inventors have obtained the following knowledge.

  That is, when the two substrates are bonded while the display medium overflows from the cell, the outer peripheral seal disposed between the two substrates is expanded in the width direction of the outer peripheral seal. Here, the inner edge portion of the spread outer peripheral seal may enter the display area. In addition, the inner edge of the outer peripheral seal that has been spread out may have an irregular wavy outline in plan view. In this case, since the pressing force acting on the display medium from the spread outer peripheral seal varies irregularly according to the irregular shape of the inner edge of the outer peripheral seal, flow disturbance occurs in the display medium, and as a result. As a result, uneven filling of the display medium occurs.

  In the method described in Patent Document 5, the presence of the second electrophoretic layer can suppress the inner edge of the spread outer peripheral seal from entering the display area, but the inner edge of the spread outer peripheral seal It is impossible to prevent the formation of an irregular wavy contour in a plan view, and therefore it is not possible to suppress the occurrence of uneven filling of the display medium.

  The present invention has been made in consideration of such points, and the object thereof is to create an irregular wavy contour in the plan view of the inner edge of the outer peripheral seal that is spread when bonding two substrates together. It is an object of the present invention to provide a method for manufacturing a reflective display device that can prevent the occurrence of filling irregularities and remarkably suppress the occurrence of uneven filling of a display medium.

  According to the present invention, a fluid display medium including at least one kind of electrophoretic material is sealed between two opposing substrates, at least one of which has a light-transmitting property, and a predetermined amount is provided between the two substrates. A method of manufacturing a reflective display device that displays information when an electric field is applied, comprising a partition forming step of forming a partition in a display region of one substrate, and an adhesion forming an adhesive layer on the partition A layer forming step, a display medium disposing step of disposing a fluid display medium on one substrate or the other substrate, and a display region on the outer side of one substrate or the display region of the other substrate An outer peripheral seal disposing step of disposing an outer peripheral seal surrounding the fluid display medium, and a substrate adhering step of adhering the one substrate and the other substrate to each other, the outer peripheral seal disposing step Then, the outer peripheral seal The height from the bottom surface to the top surface of the outer peripheral seal is greater than the height from the bottom surface of the partition wall to the top surface of the adhesive layer and less than 3 times the height from the bottom surface of the partition wall to the top surface of the adhesive layer. It is the manufacturing method of the reflection type display apparatus characterized by being arrange | positioned.

  According to the present invention, a fluid display medium containing at least one kind of electrophoretic material is sealed between two opposing substrates, at least one of which is translucent, and the two substrates are interposed between the two substrates. A method of manufacturing a reflective display device that displays information when a predetermined electric field is applied, comprising a partition formation step of forming a partition in a display region of one substrate, and on one substrate or the other A display medium disposing step of disposing a fluid display medium on the substrate, and an outer periphery surrounding the fluid display medium on the outside of the display area of one substrate or on the outside of the display area of the other substrate An outer peripheral seal arranging step of arranging a seal, and a substrate bonding step of adhering the one substrate and the other substrate to each other. In the outer peripheral seal arranging step, the outer peripheral seal is formed from a bottom surface of the outer peripheral seal. High to the top The reflective display device manufacturing method according to claim 1, wherein the height is larger than the height from the bottom surface to the top surface of the partition wall and less than three times the height from the bottom surface to the top surface of the partition wall. is there.

  Preferably, in the outer peripheral seal arranging step, the outer peripheral seal is applied in a plurality of times so as to be arranged without leaving a gap in the width direction of the outer peripheral seal.

  Preferably, in the outer peripheral seal arrangement step, the outer peripheral seal is applied using a dispenser.

  According to the present invention, it is possible to prevent the inner edge portion of the outer peripheral seal that is spread when bonding two substrates from forming an irregular wave-shaped outline in a plan view, and to generate uneven filling of the display medium. It is possible to provide a method for manufacturing a reflective display device that can be significantly suppressed.

FIG. 1 is a cross-sectional view schematically showing a configuration of a reflective display device manufactured by a method for manufacturing a reflective display device according to an embodiment of the present invention. FIG. 2 is a flowchart schematically showing a manufacturing method of the reflective display device according to the embodiment of the present invention. FIG. 3 is a diagram schematically showing an example of the partition wall forming step. FIG. 4 is a diagram schematically showing an example of the adhesive layer forming step. FIG. 5 is a diagram schematically showing an example of the display medium arranging step. FIG. 6 is a diagram schematically illustrating an example of the outer peripheral seal arrangement process. FIG. 7 is a diagram schematically showing an example of the substrate bonding step. FIG. 8 is a diagram schematically showing an example of a substrate bonding process of a comparative example in which the outer peripheral seal is arranged at a height four times as high as that of the partition wall. FIG. 9 is a flowchart schematically showing a manufacturing method of the reflective display device according to the second embodiment of the present invention. FIG. 10 is a diagram for explaining an example of the display medium arranging step.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

<Configuration of reflective display device>
FIG. 1 is a cross-sectional view schematically showing a configuration of a reflective display device manufactured by a method for manufacturing a reflective display device according to an embodiment of the present invention. This reflective display device is a fluid-like material containing at least one kind of electrically responsive material between two opposing substrates 11 and 16 on which at least one has translucency and each has electrodes formed thereon. A display medium 13 is enclosed, and a desired display is performed when a predetermined electric field is applied between the two substrates 11 and 16. The display medium 13 is surrounded by the outer peripheral seal 61. Here, the “fluid state” includes a gaseous state and a liquid state.

  The reflective display device of the present embodiment has a rectangular shape, and the outer peripheral seal 61 is correspondingly arranged in a rectangular shape (see FIGS. 6 and 7).

  Here, in the specification and claims of the present application, “translucent” means a property of transmitting light. In the present embodiment, the substrate (one substrate 11) arranged on the viewing side has a light-transmitting property such that the total light transmittance is 50% or more, preferably 80% or more, more preferably 90% or more. have.

  1 to 7, electrodes are provided on the surfaces of one substrate 11 and the other substrate 16, but the electrodes are not shown. In the present embodiment, one substrate 11 is disposed on the viewing side, and the other substrate 16 is disposed on the non-viewing side.

  One substrate 11 includes a light-transmitting film such as polyethylene (PE), polyethylene terephthalate (PET), polyethersulfone (PES), polyethylene naphthalate (PEN), or light-transmitting glass, and indium tin oxide (ITO). ), Zinc oxide (ZnO), tin oxide (SnO) or the like having a light-transmitting electrode (translucent electrode) so as to cover at least the display region 60 of one substrate 11 is typically used. Can be. Here, the “display area” refers to an area used for desired display in the reflective display device. In the present embodiment, one substrate 11 is flexible, but may be rigid. Here, in the specification and claims of the present application, “flexibility” means a degree that can be flexed. Further, “rigidity” means a property that a dimensional deformation with respect to a bending or twisting force is small.

  The translucent electrode can be formed by a coating method, a vapor deposition method, or the like. Since the translucent electrode is used as a common electrode in the case of active matrix driving and segment driving, it is not always necessary to form a pattern, and the entire surface of the substrate may be an electrode. On the other hand, in the case of passive matrix driving, since both opposing substrates need to be pattern electrodes, the translucent electrode is also formed in a pattern such as a stripe.

  The thickness of one substrate 11 is preferably 10 μm to 1 mm. If it is thinner than 10 μm, the strength as the panel 81 cannot be obtained and the risk of breakage increases. On the other hand, if it is thicker than 1 mm, the weight of the panel 81 becomes too heavy and the handling becomes inconvenient. Because it becomes higher. A suitable thickness range that is difficult to break and easy to handle is about 50 μm to 300 μm.

  One substrate 11 can be applied in either a roll shape or a sheet shape.

  As the other substrate 16, a substrate such as a resin film, a resin plate, glass, epoxy glass (glass epoxy) or the like can be used. The other substrate 16 may be a translucent base material. Furthermore, it may be an opaque base material that is translucent, but an opaque glass base material, resin film, resin plate, glass, epoxy glass with the other surface different from the electrode surface roughened. (Garaepo) or the like can be used. In the present embodiment, since the other substrate 16 is disposed at a position opposite to the viewing side, there is no necessity of having translucency. However, when the same physical properties as the one substrate 11 such as thermal expansion characteristics are required, a light-transmitting member similar to the one substrate 11 can be used. In the present embodiment, the other substrate 16 is also flexible, but may be rigid.

  As the electrode, a pattern electrode is used in the case of segment drive and passive matrix drive, and a pixel electrode in which a TFT (Thin Film Transistor) is arranged in the case of active matrix drive.

  The thickness of the other substrate 16 is preferably 10 μm to 1 mm, similarly to the thickness of the one substrate 11. If it is thinner than 10 μm, the strength as the panel 81 cannot be obtained and the risk of breakage increases. On the other hand, if it is thicker than 1 mm, the panel 81 becomes too heavy and inconvenient to handle. Because it becomes higher. A suitable thickness range that is difficult to break and easy to handle is about 50 μm to 300 μm.

The other substrate 16 can be applied in either a roll shape or a sheet shape.
An outer peripheral seal 61 that surrounds the display medium 13 is coated on one substrate 11 or the other substrate 16 with an adhesive such as an ultraviolet curable resin in a rectangular shape using a dispenser, and then with ultraviolet rays. It is formed by curing. In addition to the ultraviolet curable resin, it can be constituted by a thermosetting resin, a room temperature curable resin, a heat seal resin, or the like. In addition to the dispenser, the outer peripheral seal 61 can be arranged by various printing methods or by thermocompression bonding.

<Method for manufacturing reflective display device>
FIG. 2 is a flowchart schematically showing a manufacturing method of the reflective display device according to the embodiment of the present invention. FIG. 3 is a diagram schematically showing an example of the partition wall forming step.

  As shown in FIG. 3, first, a partition wall having a predetermined pattern is formed on the upper surface of one substrate 11 generally placed in a horizontal direction by, for example, photolithography (exposure by ultraviolet (UV) irradiation → development → firing). 12 is formed (partition wall forming step: step (1) in FIG. 2).

  In the present embodiment, one substrate 11 is arranged on the viewing side and functions as a viewing side substrate. Therefore, one substrate 11 needs to be transparent. Correspondingly, the other substrate 16 is arranged on the non-viewing side and functions as a non-viewing side substrate. On the other hand, the partition wall 12 is a member that defines a plurality of cells to be described later. For example, the pattern of the partition walls 12 has a honeycomb shape. The height of the partition wall 12 (height from the bottom surface to the top surface) is 5 μm to 50 μm, preferably 10 μm to 50 μm. The cell size depends on the size of the display panel, but is 0.05 mm to 1 mm pitch, preferably 0.1 mm to 0.5 mm pitch. But the shape of the cell formed of the partition 12 does not necessarily need to be the same for all cells. For example, a pattern made up of a plurality of randomly shaped polygons may be employed.

  The partition wall 12 can be composed of an ultraviolet curable resin, a thermosetting resin, a room temperature curable resin, or the like, and is preferably formed to a height of 5 μm to 50 μm as described above. If the thickness is 5 μm or less, the amount of ink to be filled is small, and sufficient display characteristics, in particular, contrast cannot be obtained. On the other hand, if the thickness is 50 μm or more, the panel is too thick and the drive voltage increases excessively. From the viewpoint of obtaining good display characteristics at a low driving voltage, a height in the range of 10 μm to 50 μm is preferable.

  The pattern shape of the partition walls 12 is basically arbitrary, such as a circle, a lattice, a honeycomb shape (hexagon), and other polygons. The aperture ratio is preferably 70% or more, and particularly preferably 90% or more. The higher the aperture ratio, the wider the displayable area, so that high contrast can be obtained.

  As a method for forming the partition wall 12, a mold transfer method such as embossing as well as a photolithography method may be employed. Further, a method of manufacturing a structure having a desired pattern as a partition and sticking the structure to one substrate 11 may be employed.

  Returning to FIG. 2, next, an adhesive layer 22 is formed on the partition wall 12 (adhesive layer forming step: step (2) in FIG. 2). In this adhesive layer forming step, an adhesive layer (heat sealant) 22 such as a polyester-based thermoplastic adhesive is formed with a thickness of 1 μm to 100 μm by, for example, a transfer method or a printing method. Preferably, it is formed with a thickness of 1 μm to 50 μm, particularly preferably with a thickness of 1 μm to 20 μm.

  Supplementing a specific description of an example of a typical thermal transfer method as a transfer method, for example, as shown in FIG. 4, a heat seal agent 22 such as a polyester-based thermoplastic adhesive having a thickness of 20 μm on a PET film 21. Is prepared, and the surface of the heat sealant 22 of the transfer sheet 20 is laminated on the partition wall 12 at a normal temperature and a pressure of 1 kPa. This is heated for 1 minute on a hot plate maintained at, for example, 120 °, which is equal to or higher than the softening temperature of the heat sealant 22, and then the transfer sheet 20 is peeled off. Thereby, an adhesive layer 22 of about 6 μm, for example, is formed on the partition wall 12.

  The adhesive layer (heat sealant) 22 is preferably made of a thermoplastic material, has a property of softening by heating and solidifying when cooled, and the composition is reversible when cooling and heating are repeated. It is a material that is kept in a safe manner.

  When the heat sealant 22 made of a thermoplastic material is used as an adhesive layer, the heat sealant 22 solidified on the transfer film substrate is softened by heating to a temperature exceeding its softening temperature, The heat sealing agent 22 can be reliably thermally transferred only to the top surface of the partition wall 12. Further, since the heat sealant 22 after heat transfer is cooled to room temperature and solidified again, tackiness, that is, stickiness is eliminated, so that it is very convenient to handle. Further, since there is no tack, that is, no stickiness, the display medium 13 filled in the cell is not bonded to the adhesive. Then, the adhesive on the top surface of the partition wall 12 is again heated to a temperature exceeding its softening temperature and softened, so that it has tack, that is, stickiness, so that it is securely bonded to the other substrate 16. . Since the heat sealant 22 after being bonded to the other substrate 16 is not tacked again at room temperature, i.e., is not sticky, the display medium 13 is not bonded to the heat sealant 22 again, and the display quality is deteriorated. There is no fear of it.

  Specific examples of the adhesive layer (heat sealant) 22 include thermoplastic base polymers such as ethylene-vinyl acetate copolymer, polyester, polyamide, polyolefin, polyurethane, natural rubber, and styrene-butadiene block copolymer. Mainly thermoplastic elastomers such as styrene-isoprene block copolymer, styrene-ethylene-butylene-styrene block copolymer, styrene-ethylene-propylene-styrene copolymer, and compounded tackifier resin and plasticizer The used resin is mainly used.

  In order to improve the adhesion between the partition wall 12 and the adhesive layer 22, the partition wall 12 may be subjected to a surface treatment by ultraviolet irradiation, plasma treatment, or the like, or a primer may be formed. Alternatively, a silane coupling agent may be added to the adhesive layer 22.

  Returning to FIG. 2, next, the partition 12 or each region partitioned by the partition 12 and the adhesive layer 22 is defined as a cell, and liquid ink 13 as a display medium is disposed in each cell (display medium). Arrangement step: step (3) in FIG.

  FIG. 5 is a diagram schematically showing an example of the display medium arranging step. Here, (1) Ink 13 is dripped from the dispenser 31 or inkjet or die coat (ink application process, (2) Ink 13 is applied in-plane by the applicator 32 or doctor blade, doctor knife, and central squeegee to be uniform. However, even in this state, there is an amount of ink 13 that exceeds the volume of each cell, that is, there is an excess of ink 13.

  The display medium (ink) 13 includes at least one or more kinds of electrically responsive materials. Examples of the electroresponsive material include a charged particle material and a liquid crystal material. The charged particle material is a so-called electrophoretic material in which colored particles such as white, black, and color move in response to an electric field, or a material typified by a twist ball that is colored in two colors and rotated by the electric field. Or a nanoparticle material that moves by an electric field. On the other hand, liquid crystal materials include materials known for PDLC (Polymer Dispersed Liquid Crystal) that electrically control transmission and scattering, materials in which liquid crystals are mixed with dyes, and cholesteric liquid crystal materials. These materials that change optical characteristics in response to an electric response need to be isolated into cells regardless of the type, and are within the scope of the present invention.

  Returning to FIG. 2, next, the outer peripheral seal 61 surrounding the fluid display medium 13 is arranged in a rectangular shape on the outside of the display area 60 of the other substrate 16 (peripheral seal arrangement step: step of FIG. 2). (4)). In the present embodiment, the outer peripheral seal 61 has a height H1 from the bottom surface to the top surface of the outer peripheral seal 61 that is greater than a height H2 from the bottom surface of the partition wall 12 to the top surface of the adhesive layer 22 and from the bottom surface of the partition wall 12. It arrange | positions so that it may become less than 3 times the height H2 to the top face of the contact bonding layer 22 (namely, it becomes H2 <H1 <3xH2).

  Here, with regard to the height from the bottom surface to the top surface of the partition wall 12 and the height from the bottom surface of the partition wall 12 to the top surface of the adhesive layer 22, for example, a fully automatic fine shape measuring machine (Surfcoder ET4000L: manufactured by Kosaka Laboratory). ) Is used to measure a plurality of arbitrary locations, and an arithmetic average of a plurality of measured values can be obtained. For the height from the bottom surface to the top surface of the outer peripheral seal 61, for example, a high precision non-contact level difference measuring device (Hismet IIDHII: manufactured by Union Optics) is used to measure a plurality of arbitrary positions, and a plurality of measured values are arithmetically calculated. It can be obtained by averaging.

  Supplementing a specific description of an example of the arrangement method of the outer peripheral seal 61, as shown in FIG. 6, the outer peripheral seal 61 uses an adhesive such as an ultraviolet curable resin, for example, by using the dispenser 41. It arrange | positions by apply | coating to a linear form along the outer periphery of this. When the dispenser 41 is used, it is easy to arrange the outer peripheral seal 61 at a desired height by adjusting conditions such as the diameter of the application needle, the dispensing pressure, and the application speed.

  In addition, the outer peripheral seal 61 of the present embodiment is applied in a plurality of times so as to be arranged without leaving a gap in the width direction of the outer peripheral seal 61. Specifically, for example, as shown in FIG. 6, after the first pattern is applied by moving the dispenser 41 so as to go around the outer periphery of the display area 60 of the other substrate 16, the first pattern is applied. The dispenser 41 is further rounded the outer periphery of the display area 60 so that the next pattern is arranged without leaving a gap on the outer side in the width direction of the pattern, so that the outer peripheral seal 61 is applied in a total of two times. Alternatively, after the first pattern is applied, the dispenser 41 is further rotated once around the outer periphery of the display area 60 so that the next pattern is arranged without leaving a gap inside the first pattern in the width direction. The outer peripheral seal 61 may be applied in a total of two times. Moreover, the frequency | count of application | coating may be more than twice.

  As described above, the outer peripheral seal 61 is applied in a plurality of times, so that the height H1 from the bottom surface to the top surface of the outer peripheral seal 61 is set to the height H2 from the bottom surface of the partition wall 12 to the top surface of the adhesive layer 22. The width of the outer peripheral seal 61 can be widened while suppressing to less than three times. Further, since the outer peripheral seal 61 is applied in a plurality of times without leaving a gap in the width direction, the display medium 13 is not confined between the outer peripheral seals 61 adjacent in the width direction in the substrate bonding step. The outer peripheral seal 61 is prevented from being broken by the pressure of the confined display medium 13.

  In the present embodiment, the outer peripheral seal 61 is disposed on the outer periphery of the display area 60 of the other substrate 16, but the present invention is not limited to this, and the outer peripheral seal 61 is provided on the outer periphery of the display area 60 of the one substrate 11. May be arranged. In this case, the outer peripheral seal 61 should be arranged before the display medium 13 is arranged on one substrate 11.

  Next, the adhesive layer 22 on the partition wall 12 is bonded to the other substrate 16 facing the one substrate 11 (substrate bonding step: step (5) in FIG. 2). Thereby, the display medium 13 is sealed in each cell.

  In the substrate bonding step, the heat sealing agent and the outer peripheral seal 61 applied as the adhesive layer 22 are heated to obtain an adhesive force. Specifically, while applying a predetermined thermocompression pressure (laminate pressure) by the laminator 91, the adhesive layer 22 and the outer peripheral seal 61 are heated from the periphery to a temperature exceeding the softening temperature to be softened, whereby the partition wall 12. And the other substrate 16 are bonded. However, other thermocompression bonding modes may be employed.

  Here, in the substrate bonding process of the present embodiment, the other substrate 16 is curled so that no bubbles remain in the cell between the one substrate 11 and the other substrate 16, and the rectangular shape of the outer peripheral seal 61 is obtained. From one side of the shape (the right side in FIG. 7) to the other side (the left side in FIG. 7) facing each other, a portion where the one substrate 11 and the other substrate 16 are pressed against each other by the laminator 91 The excess display medium 13 on one substrate 11 is bonded while being pushed out from the region surrounded by the outer peripheral seal 61.

  In the present embodiment, in the outer periphery seal arrangement step, the height H1 from the bottom surface to the top surface of the outer periphery seal 61 is greater than the height H2 from the bottom surface of the partition wall 12 to the top surface of the adhesive layer 22. In addition, since it is arranged to be less than three times the height H2 from the bottom surface of the partition wall 12 to the top surface of the adhesive layer 22 (H2 <H1 <3 × H2), a laminator 91 is used in the substrate bonding step. When the outer peripheral seal 61 is spread by the deformation amount of the outer peripheral seal 61 is relatively small. Therefore, a part of the outer peripheral seal 61 that has been spread out is prevented from entering the display area 60. Further, it is possible to prevent the inner edge portion of the outer peripheral seal 61 that has been spread out from forming an irregular wavy contour in plan view. Thereby, the variation in the pressing force that acts on the display medium 13 from the spread outer peripheral seal 61 is reduced, and the flow disturbance of the display medium 13 is suppressed. As a result, occurrence of filling unevenness in the display medium 13 can be suppressed.

  Subsequently, the region where the outer peripheral seal 61 is disposed is irradiated with ultraviolet rays, and the outer peripheral seal 61 is cured.

  Then, returning to FIG. 2, the panel 81 is cut to a predetermined size by a cutting device 51 such as a guillotine, an upper blade slide device, a laser cutting device, or a laser cutter, and the manufacture of a desired reflective display device is completed (cutting). Step: Step (6) in FIG.

  According to the present embodiment as described above, in the outer peripheral seal arranging step, the height H1 from the bottom surface to the top surface of the outer peripheral seal 61 is from the bottom surface of the partition wall 12 to the top surface of the adhesive layer 22. And the height H2 from the bottom surface of the partition wall 12 to the top surface of the adhesive layer 22 is less than three times (that is, H2 <H1 <3 × H2). In the substrate bonding step, the deformation amount of the outer peripheral seal 61 is reduced, and the inner edge portion of the outer peripheral seal 61 that has been spread out is prevented from forming an irregular wavy contour in plan view. Therefore, the variation in the pressing force acting on the display medium 13 from the spread outer peripheral seal 61 is reduced, the flow disturbance of the display medium 13 is suppressed, and as a result, the occurrence of uneven filling of the display medium 13 is significantly suppressed. can do.

  On the other hand, when the height from the bottom surface to the top surface of the outer peripheral seal 161 is not less than three times the height from the bottom surface of the partition wall 12 to the top surface of the adhesive layer 22 as in the comparative example shown in FIG. In the process, when the outer peripheral seal 161 is expanded by the laminator 91, the deformation amount of the outer peripheral seal 161 is relatively large. Therefore, the inner edge of the outer peripheral seal 161 that has been spread out may enter the display area 60. Moreover, the inner edge part of the outer peripheral seal 161 that has been spread out may form an irregular wavy contour in plan view. In this case, since the pressing force acting on the display medium 13 from the spread outer peripheral seal 161 changes irregularly according to the irregular shape of the inner edge portion of the outer peripheral seal 161, flow disturbance occurs in the display medium 13. As a result, there is a problem that uneven filling occurs in the display medium 13.

  Further, according to the present embodiment, in the outer peripheral seal arranging step, the outer peripheral seal 61 is applied in a plurality of times so as to be arranged without leaving a gap in the width direction of the outer peripheral seal 61. The width of the outer peripheral seal 61 can be increased while suppressing the height H1 from the bottom surface to the top surface to be less than three times the height H2 from the bottom surface of the partition wall 12 to the top surface of the adhesive layer 22. Further, since the outer peripheral seal 61 is applied in a plurality of times without leaving a gap in the width direction, the display medium 13 is not confined between the outer peripheral seals 61 adjacent in the width direction in the substrate bonding step. The outer peripheral seal 61 is prevented from being broken by the pressure of the confined display medium 13.

  Moreover, according to this Embodiment, since the outer periphery seal 61 is apply | coated using the dispenser 41 in an outer periphery seal arrangement | positioning process, it is easy to arrange | position the outer periphery seal 61 by desired height.

  In the present embodiment, an adhesive layer forming step is performed on the top of the partition wall 12, but the panel 81 is sealed and bonded by the outer peripheral seal 61 arranged on the outer periphery of the display region 60. As shown in FIG. 2, the adhesive layer forming step for the top of the partition wall 12 can be omitted (second embodiment). In this case, as shown in FIG. 9, in the outer peripheral seal placement step, the height H1 from the bottom surface to the top surface of the outer periphery seal 61 is greater than the height H3 from the bottom surface to the top surface of the partition wall 12. And it arrange | positions so that it may become less than 3 times the height H3 from the bottom face of the partition 12 to a top face (namely, it becomes H3 <H1 <3 * H3). Also according to such an aspect, the same effect as the first embodiment can be obtained.

  The above embodiment can also be applied to the case where a plurality of reflective display devices are manufactured from a mother substrate. In this case, the outer peripheral seal placement step shown in FIG. 6 is performed on each display area of the reflective display device. That is, the outer periphery seal arrangement process shown in FIG. 6 is performed for each display area.

  Note that the above embodiment can be applied in principle when the electrophoretic body is a charged powder and the display medium is a gas.

  Further, the display medium 13 is not limited to the one that electrically changes the optical characteristics, but may be one that responds to an external field caused by magnetism or heat. It can be applied regardless. Further, the display medium arranging step is not limited to the above-described embodiment as shown in FIG. 10A, and the arrangement of the one substrate 11 and the other substrate 16 is reversed so that the display area of the other substrate 16 is displayed. The display medium 13 may be disposed on 60 (see FIG. 10B). If the display medium 13 has a certain degree of viscosity (fluidity is not excessively high), instead of disposing the display medium 13 on the display area 60 of the one substrate 11 on which the partition walls 12 are formed, The display medium 13 may be disposed on the display area 60 of the other substrate 16 that is to be opposed to the display area 60 of the substrate 11 (see FIG. 10C). The display medium 13 may be arranged on the display area 60 of one substrate 11 by reversing the arrangement of (see FIG. 10D).

  Next, practical examples actually performed will be described.

<Example 1>
As one substrate 11, an indium tin oxide (ITO) vapor deposition film (thickness 0.2 μm) was provided as a transparent electrode on one surface of a 300 mm × 400 mm × 0.125 mm thick PET film (Toyobo A4100). A substrate was prepared.

Next, a negative photosensitive resin material (a dry film resist manufactured by DuPont MRC Dry Film Resist Co., Ltd.) is laminated on the one substrate 11 to a thickness of 20 μm and heated at 100 ° C. for 1 minute. Then, exposure is performed using an exposure mask (exposure amount: 500 mJ / cm ² ), and thereafter development using a 1% KOH aqueous solution is performed for 30 seconds, followed by baking at 200 ° C. for 60 minutes. The honeycomb-shaped pattern partition walls 12 having a top width of 15 μm and a cell pitch of 300 μm were formed.

  Next, using a pressure-sensitive adhesive substrate in which a heat sealant (Byron 550 manufactured by Toyobo Co., Ltd.) is formed on the PET film 21 with a thickness of 10 μm, and a silicone sheet is bonded to a glass substrate with a thickness of 2 mm as an anti-distortion substrate, The PET film 21 with a heat seal layer is fixed flatly, and after the heat seal layer is thermocompression-bonded (130 ° C., 1 kPa) to the top of the partition wall 12, the PET film 21 is separated from the partition wall 12, so that the entire top surface of the partition wall 12 is formed. An adhesive layer (heat seal layer) 13 was formed. Here, the height H2 from the bottom surface of the partition wall 12 to the top surface of the adhesive layer 22 was 30 μm. The height H2 from the bottom surface of the partition wall 12 to the top surface of the adhesive layer 22 is the hexagonal side of the partition wall 12 forming any one cell among the hexagonal cells formed by the partition wall 12. It is a value obtained by measuring five locations in the vicinity of the midpoint using a fully automatic fine shape measuring machine (Surfcoder ET4000L: manufactured by Kosaka Laboratory) and arithmetically averaging all measured values.

  Subsequently, ink having the following components is used as the display medium 13, dropped from the dispenser, squeezed with a central squeegee (Neurong squeegee: urethane resin), and filled into each cell. It was.

(Ink component)
・ Electrophoretic particles (titanium dioxide): 60 parts by weight ・ Dispersion liquid: 40 parts by weight

  Next, as the other substrate 16, a non-alkali glass (OA-10G manufactured by Nippon Electric Glass Co., Ltd.) having a size of 300 mm × 400 mm × thickness 0.7 mm and various electrodes such as Cu electrodes formed in a pattern were used. . Various electrode patterns were formed by a general etching method.

  Subsequently, along the outer periphery of the display area 60 of the other substrate 16, an ultraviolet curable resin (manufactured by Three Bond Co., Ltd .: acrylic sealant 3052D) is applied without any break using a dispenser, so that the outer peripheral seal 61 is The height H1 from the bottom surface to the top surface was 60 μm with a rectangular shape in plan view of 200 mm × 300 mm. More specifically, the dispenser is moved so as to make one round of the outer periphery of the display area 60 of the other substrate 16 under the conditions of an inner diameter of the coating needle of 0.4 mm, a dispensing pressure of 0.2 MPa, and a coating speed of 15 mm / s. After the first pattern has been applied, the dispenser is placed so that the next pattern is arranged in order without leaving a gap outside the first pattern (ie, on the side opposite the display area side with respect to the first pattern). By making the outer periphery of the display area 60 five more times, the outer peripheral seal 61 was applied in a total of six times. The height H1 from the bottom surface to the top surface of the outer peripheral seal 61 is measured at a midpoint on each side of the rectangular shape using a high-precision non-contact level difference measuring machine (Hismet IIDHII: manufactured by Union Optics). It is a value obtained by arithmetically averaging the measured values at four locations.

Thereafter, in the atmosphere, the other substrate 16 is aligned and superposed on the adhesive layer 22 on the partition wall 12 of one substrate 11, and a constant thermocompression pressure is applied by the laminator 91 to keep the inside of the partition wall 12. The partition 12 of one substrate 11 and the other substrate 16 were brought into close contact with each other while extruding the surplus of the display medium 13 exceeding the cell volume (see FIG. 7). At this time, the other substrate 16 was in close contact with the partition wall 12 so that no bubbles remained in the cell. The temperature during thermocompression bonding was 100 ° C. Moreover, the thermocompression bonding pressure was 0.1 MPa. Thereafter, the outer peripheral seal 61 was exposed to ultraviolet rays (exposure amount 3000 mJ / cm ² ), and the outer peripheral seal 61 was cured.

  When the quality of the display panel obtained as described above was evaluated, neither penetration of the outer peripheral seal 61 into the display region 60 nor occurrence of uneven filling of the display medium 13 was confirmed.

<Example 2>
The outer peripheral seal arrangement step was changed with respect to Example 1, and the outer peripheral seal 61 had a rectangular shape of 200 mm × 300 mm in plan view, and a height H1 from the bottom surface to the top surface was formed to 80 μm. More specifically, the dispenser is moved so as to make one round of the outer periphery of the display area 60 of the other substrate 16 under the conditions of an inner diameter of the coating needle of 0.57 mm, a dispensing pressure of 0.1 MPa, and a coating speed of 15 mm / s. After the first pattern has been applied, the dispenser is placed so that the next pattern is arranged in order without leaving a gap outside the first pattern (ie, on the side opposite the display area side with respect to the first pattern). The outer periphery of the display area 60 was further rotated once, so that the outer periphery seal 61 was applied in a total of two times. The other steps were the same process to create a display panel.

  As a result of evaluating the quality of the display panel thus obtained, neither penetration of the outer peripheral seal 61 into the display region 60 nor occurrence of uneven filling of the display medium 13 was confirmed.

<Comparative Example 1>
The outer peripheral seal arrangement step was changed with respect to Example 1, and the outer peripheral seal 61 had a rectangular shape of 200 mm × 300 mm in plan view, and the height H1 from the bottom surface to the top surface was formed to 100 μm. More specifically, the dispenser is moved so as to make one round of the outer periphery of the display area 60 of the other substrate 16 under the conditions of an inner diameter of the coating needle of 0.78 mm, a dispensing pressure of 0.1 MPa, and a coating speed of 15 mm / s. The outer periphery seal 61 was applied without dividing the application multiple times. The other steps were the same process to create a display panel.

  When the quality of the display panel thus obtained was evaluated, it was confirmed that the outer peripheral seal 61 entered the display area 60 and the display medium 13 was filled unevenly.

  It is considered that as the height of the outer peripheral seal 61 arranged in the outer peripheral seal arranging step becomes larger, the deformation amount of the outer peripheral seal 61 in the substrate bonding step becomes larger, so that uneven filling of the display medium 13 is likely to occur. From the verification result, when the height H1 of the outer peripheral seal 61 arranged in the outer peripheral seal arrangement step is 100/30 = 3.3 times or more of the height H2 from the bottom surface of the partition wall 12 to the top surface of the adhesive layer 22, display is performed. It has been found that the outer peripheral seal 61 enters the region 60 and the filling unevenness of the display medium 13 occurs.

11 One substrate 12 Partition 13 Display medium 16 Other substrate 20 Transfer sheet 21 PET film 22 Adhesive layer (heat seal agent)
31 Dispenser 32 Applicator 41 Dispenser 51 Cutting device 60 Display area 61 Perimeter seal 91 Laminator H1 Height from bottom surface to top surface of outer periphery seal H2 Height from bottom surface of partition wall to top surface of adhesive layer H3 Top from bottom surface of partition wall Height to face

Claims (4)

A fluid display medium containing at least one kind of electrophoretic body is sealed between two opposing substrates, at least one of which has translucency, and a predetermined electric field is applied between the two substrates. A method of manufacturing a reflective display device that displays information when
A partition formation step of forming a partition in the display region of one substrate;
An adhesive layer forming step of forming an adhesive layer on the partition;
A display medium disposing step of disposing a fluid display medium on one substrate or the other substrate;
An outer peripheral seal disposing step of disposing an outer peripheral seal surrounding a fluid display medium on the outer side of the display region of one substrate or the outer side of the display region of the other substrate;
A substrate bonding step of bonding the one substrate and the other substrate to each other;
With
In the outer peripheral seal arranging step, the height of the outer peripheral seal from the bottom surface to the top surface of the outer peripheral seal is greater than the height from the bottom surface of the partition wall to the top surface of the adhesive layer, and from the bottom surface of the partition wall to the adhesive layer. A method for manufacturing a reflective display device, characterized in that the reflective display device is disposed so as to be less than three times the height to the top surface of the display. A fluid display medium containing at least one kind of electrophoretic body is sealed between two opposing substrates, at least one of which has translucency, and a predetermined electric field is applied between the two substrates. A method of manufacturing a reflective display device that displays information when
A partition formation step of forming a partition in the display region of one substrate;
A display medium disposing step of disposing a fluid display medium on one substrate or the other substrate;
An outer peripheral seal disposing step of disposing an outer peripheral seal surrounding a fluid display medium on the outer side of the display region of one substrate or the outer side of the display region of the other substrate;
A substrate bonding step of bonding the one substrate and the other substrate to each other;
With
In the outer peripheral seal arrangement step, the outer peripheral seal has a height from the bottom surface to the top surface of the outer peripheral seal that is greater than a height from the bottom surface to the top surface of the partition wall and a height from the bottom surface to the top surface of the partition wall. A method of manufacturing a reflective display device, wherein the reflective display device is arranged so as to be less than three times. 3. The reflection according to claim 1, wherein in the outer peripheral seal arranging step, the outer peripheral seal is applied in a plurality of times so as to be arranged without leaving a gap in the width direction of the outer peripheral seal. Manufacturing method of type display device. 4. The method of manufacturing a reflective display device according to claim 1, wherein in the outer peripheral seal arranging step, the outer peripheral seal is applied using a dispenser.

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