JP2011215298A - Electrophoretic display device and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophoretic display device in which maldistribution of electrophoretic bodies is prevented in a region where no electrodes are disposed, and which maintains high display quality, and to provide a method for manufacturing the electrophoretic display device.SOLUTION: A fundamental arrangement pattern of cells is a honeycomb-like pattern, and an arrangement pattern of electrodes is a lattice-like pattern. Electrode boundary partitions standing from on a lower substrate are formed in portions where no electrodes are formed. Cell boundary partitions standing from on the lower substrate or electrodes are formed in an arrangement pattern which is designed in consideration of a formation pattern of the electrode boundary partitions on the basis of the prescribed fundamental arrangement pattern of a cell.

Description

  The present invention relates to an electrophoretic display device applied to electronic paper and the like, and a manufacturing method for manufacturing the electrophoretic display device.

  The electrophoretic display device is a device that displays information by using electrophoretic migration (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.

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

  However, in an electrophoretic display device, display defects (particularly, a decrease in contrast) may occur due to particle sedimentation or uneven distribution. In order to prevent this phenomenon, it is used to form partition walls between the upper and lower electrode substrates to divide the migration (movement) space of the particles to be electrophoresed into minute spaces. This minute space is called a cell (or pixel). In each cell, an electrophoretic body (or ink containing the electrophoretic body) that performs electrophoresis is enclosed.

  Here, when the material used as the substrate is a film, the film is relatively easily deformed, so that there is a problem that a gap is easily generated between the partition wall and the electrode substrate. Therefore, it is important to securely bond between the partition wall and the electrode substrate to prevent ink from passing and moving between the partition wall and the electrode substrate.

  Japanese Patent Laid-Open No. 2006-184893 (Patent Document 1) discloses a technical information display panel (one aspect of an electrophoretic display device) by forming an adhesive layer on a top surface of a partition formed on a substrate with high accuracy and low cost. Is disclosed. Specifically, a method is disclosed in which a roll coated with an adhesive (ultraviolet curable resin or thermosetting resin) is rotated to transfer the adhesive onto partition walls at room temperature.

JP 2006-184893 A JP 2004-4773 A

  Even if the inventor prevents the ink from passing between the partition wall and the electrode substrate, if the electrode arrangement pattern and the partition arrangement pattern are different, the display quality deteriorates in the region where both patterns intersect. I found out. That is, as shown in FIG. 10, when the partition arrangement pattern is a honeycomb shape and the electrode arrangement pattern is a pattern other than the honeycomb shape, the present inventors have found that the electrophoretic body is unevenly distributed in a region where no electrode is arranged. It was found that occurs.

  An electrophoretic display described in Japanese Patent Application Laid-Open No. 2004-4773 (Patent Document 2) employs an elongated rectangular electrode arrangement pattern and a grid-like partition wall pattern. The elongated rectangular pattern completely overlaps with the grid pattern, and thus the above-described problem does not occur.

  The present invention has been made based on such circumstances, and an object of the present invention is to prevent the electrophoretic body from being unevenly distributed in a region where no electrode is disposed and to maintain high display quality. An electrophoretic display device and a method for manufacturing the same are provided.

  The present invention has a plurality of cells between two opposing substrates, at least one of which is transparent, and each cell contains a display medium containing at least one or more electrophores, A method of manufacturing an electrophoretic display device in which a display medium displays predetermined information when a predetermined electric field is applied between the two substrates, wherein a plurality of electrodes are formed on one substrate. An electrode formation step of forming an arrangement pattern; an electrode boundary partition formation step of forming an electrode boundary partition wall in a portion where the electrode is not formed on the one substrate; and a predetermined cell arrangement pattern on the one substrate or the A cell boundary partition forming step for forming a cell boundary partition on the electrode, a display medium filling step for filling the display medium with each region partitioned by the cell boundary partition as a cell, and / or on the electrode boundary partition and / or A substrate bonding step of sealing the display medium by bonding the other substrate onto the cell boundary partition wall, wherein the cell arrangement pattern is a circular or polygonal pattern, and the electrode arrangement The pattern is a method of manufacturing an electrophoretic display device, wherein the pattern is different from the cell arrangement pattern.

  According to the present invention, high display quality can be maintained due to the difference between the cell arrangement pattern and the electrode arrangement pattern. On the other hand, by providing the electrode boundary partition wall on the substrate in the portion where the electrode is not formed, Uneven distribution can be effectively suppressed, and as a result, high display quality can be obtained.

  Here, the electrode boundary partition wall is preferably formed with the same width as the gap where the electrode is not formed in order to fill the gap portion where the electrode is not formed, but a width narrower than the gap where the electrode is not formed may be adopted. .

  Further, in order to maintain a higher display quality, it is preferable that the line width of the cell boundary partition is formed narrower than the line width of the electrode boundary partition.

  In general, the electrode boundary partition wall forming step and the cell boundary partition wall forming step are performed simultaneously.

  Preferably, the method for manufacturing an electrophoretic display device according to the present invention further includes an adhesive layer forming step of forming an adhesive layer on the electrode boundary partition wall and / or the cell boundary partition wall. The heat sealing agent is thermally transferred using a transfer substrate on which a heat sealing agent using a thermoplastic material is formed, and the display medium filling step is performed after the adhesive layer is formed. And the substrate bonding step includes a heating step of re-softening the heat sealant transferred as an adhesive layer to obtain an adhesive force, on the electrode boundary partition and on the adhesive layer on the cell boundary partition The display medium is sealed by bonding the other substrate.

  In this case, by using a heat sealant using a thermoplastic material as an adhesive, the partition and the other substrate can be reliably bonded to each other with a simple process. In addition, by using a transfer substrate when the heat sealant is thermally transferred, high-precision alignment on the partition walls is unnecessary, but the heat seal agent can be reliably thermally transferred only to the partition wall upper surface.

  Further, a heat sealant using a thermoplastic material thermally transferred as an adhesive layer has no tack (stickiness) at room temperature, and is very convenient to handle. Further, since there is no tack (stickiness), the subsequent display medium filling process is easy. For example, even if the display medium is filled with a squeegee or the like, the display medium does not adhere to the heat sealant.

  And since the other board | substrate is adhere | attached reliably by heat-sealing agent being heated, even if the other board | substrate deform | transforms, an adhesion part does not peel, ie, a display medium moves undesirably. Such a void does not occur. Further, since there is no possibility that impurities enter the cell when the other substrate is bonded, there is no risk of deterioration in display quality. And since the heat sealant after bonding the other substrate has no tack at room temperature, the display medium will not adhere to the heat sealant, which also reduces the display quality. There is no fear.

  Preferably, the substrate bonding step further includes a heating laminating step of applying a predetermined pressing force to obtain an adhesive force. In this case, the other substrate is more reliably bonded.

  Preferably, the heat sealing agent has a thickness of 1 to 100 μm. More preferably, it is 1-50 micrometers, Most preferably, it is 1-10 micrometers.

  Preferably, the partition wall has a thickness of 5 to 100 μm. More preferably, it is 10-50 micrometers.

  Alternatively, the present invention has a plurality of cells between two opposing substrates, at least one of which is transparent, and each cell contains a display medium containing at least one or more electrophores. An electrophoretic display device in which the display medium displays predetermined information when a predetermined electric field is applied between the two substrates, the electrodes disposed in a predetermined pattern on one substrate; And an electrode boundary partition disposed in a portion where the electrode is not formed, and a cell boundary partition disposed in a predetermined cell layout pattern on the one substrate or on the electrode, and is partitioned by the cell boundary partition. In addition, each region is a cell, and the display medium is included in the cell. The cell arrangement pattern is a circular or polygonal pattern, and the electrode arrangement pattern is different from the cell arrangement pattern. It is an electrophoretic display device which is a pattern.

  According to the present invention, high display quality can be maintained due to the difference between the cell arrangement pattern and the electrode arrangement pattern, while the electrode boundary partition walls are provided on the substrate in the portion where the electrode is not formed. The uneven distribution of the migrating body can be effectively suppressed, and as a result, high display quality can be obtained.

  The electrode boundary partition wall is preferably formed with the same width as the gap where the electrode is not formed in order to fill the gap portion where the electrode is not formed, but a width narrower than the gap where the electrode is not formed may be adopted.

  Further, in order to maintain higher display quality, it is preferable that the cell boundary partition is formed thinner than the electrode boundary partition.

  High display quality can be maintained due to the difference between the cell arrangement pattern and the electrode arrangement pattern. On the other hand, by providing an electrode boundary partition on the substrate where no electrode is formed, it is possible to effectively suppress the uneven distribution of the electrophoretic body. As a result, high display quality can be obtained.

FIG. 1 is a diagram schematically showing an initial process of a method for manufacturing an electrophoretic display device according to an embodiment of the present invention. FIG. 2 is a diagram schematically showing an arrangement pattern of electrodes. FIG. 3 is a diagram schematically showing a basic arrangement pattern of cells. FIG. 4 is a diagram schematically showing another example of the basic arrangement pattern of cells. FIG. 5 is a diagram schematically showing an electrode boundary partition and a cell boundary partition. FIG. 6 is a diagram schematically showing a middle step of the method of manufacturing the electrophoretic display device according to the present embodiment. FIG. 7 is a diagram schematically showing an example of the adhesive layer forming step. FIG. 8 is a diagram schematically showing the final stage of the manufacturing method of the electrophoretic display device according to the present embodiment. FIG. 9 is a schematic diagram for explaining the function of the conductive paste. FIG. 10 is a schematic diagram for explaining the uneven distribution of the electrophoretic body.

  FIG. 1 is a diagram schematically showing an initial process of a method for manufacturing an electrophoretic display device according to an embodiment of the present invention.

  As shown in FIG. 1, an electrode arrangement pattern for applying a predetermined electric field between two substrates is first designed (electrode pattern design process). In this case, the arrangement pattern of the electrodes 11a is a lattice pattern as shown in FIG.

  Next, in the portion 11b where the electrode 11a is not formed, an arrangement pattern of the electrode boundary partition 12a is designed on the substrate (electrode boundary partition design step), and the arrangement of the electrode boundary partition 12a is based on the predetermined cell arrangement pattern. In consideration of the pattern, the cell arrangement pattern, that is, the arrangement pattern of the cell boundary partition 12b is designed (cell pattern design process).

  The predetermined cell arrangement pattern is a honeycomb pattern as shown in FIG. 3, or a polygonal pattern such as a circular pattern or a lattice, which is most suitable for display quality. Here, in the specification and claims of the present application, the honeycomb-shaped pattern includes a pattern that includes other patterns in a weighted manner. For example, a pattern as shown in FIG. 4 is also included in the “honeycomb pattern” in the specification and claims of the present application. In the specification and claims of the present application, “different” patterns mean that the patterns are not identical to each other and one does not have a relationship including the other. In the present embodiment, the arrangement pattern of the electrode boundary partitions 12a is the same as the width of the gap 11b where no electrode is formed so as to fill the gap portion where the electrode 11a is not formed. The cell arrangement pattern, that is, the arrangement pattern of the cell boundary partition wall 12b is a honeycomb pattern as shown in FIG. 5 in consideration of the formation pattern of the electrode boundary partition wall 12a. Further, the cell boundary partition 12b is designed to be thinner than the electrode boundary partition 12a. As a result, the opening area of each cell partitioned by the cell boundary partition 12b is increased and the displayable area is widened, so that high contrast can be obtained. In addition, since the width of the cell boundary partition wall 12b is narrowed, the partition wall is hardly visible when the display device is formed.

The reason why the honeycomb pattern is selected as the arrangement pattern of the cell boundary partition walls 12b will be described below. With almost the same aperture ratio, an adhesive layer is formed on the partition provided on one substrate for the lattice pattern, honeycomb pattern, and circular pattern, and the adhesive layer is bonded to the other base material As a result of comparison, the adhesive strength was stronger when the honeycomb pattern or the circular pattern was adopted. Moreover, when the ease of mixing of bubbles at the time of bonding was compared, it was confirmed that the honeycomb pattern tends to be less likely to be mixed than the lattice pattern and the circular pattern. Based on these results, a honeycomb pattern was selected. In addition, about the adhesive force of the base material, it measured by the 180 degree | times tensile test (JISK6854-2 conformity) using the peeling tester (made by A & D). In addition, the suitability of the bonding process is confirmed by visual check, and almost no bubbles are mixed (◎), bubbles are mixed but inconspicuous (○), and bubbles are conspicuous (△). Was evaluated.

  Next, a plurality of electrodes 11a are formed on one substrate 11 with the designed electrode arrangement pattern (electrode formation step).

  Then, the electrode boundary partition wall 12a and the cell boundary partition wall 12b are formed according to the designed arrangement pattern of the electrode boundary partition wall 12a and the similarly designed layout pattern of the cell boundary partition wall 12b. In the present embodiment, the electrode boundary partition 12a and the cell boundary partition 12b are formed simultaneously.

  Hereinafter, the electrode boundary partition 12 a and the cell boundary partition 12 b are collectively expressed as the partition 12. In short, the partition 12 is a pattern shown in FIG.

  FIG. 6 is a diagram schematically showing a middle step of the method of manufacturing the electrophoretic display device according to the present embodiment. As shown in FIG. 6, the upper surface (on the substrate 11 or on the electrode 11a) of one substrate 11 (backplane base material: BP) on which the electrode 11a is formed is exposed by, for example, photolithography (ultraviolet (UV) irradiation). The partition 12 is formed in the pattern of FIG. 5 by (development → firing) (partition forming step). The partition wall 12 is a member that defines lower surfaces and side surfaces of a plurality of cells to be described later. The thickness of the partition wall is 5 to 100 μm, preferably 10 to 50 μm.

  Next, an adhesive layer is formed on the partition wall 12 (adhesive layer forming step). FIG. 7 is a diagram schematically showing an example of the adhesive layer forming step. In the adhesive layer forming step shown in FIG. 7, first, a transfer film 20 (=) is applied by applying a heat sealant 22 using a thermoplastic material to a transfer film substrate 21 (for example, polyethylene terephthalate (PET) film). Transfer substrate) is created. The heat sealing agent 22 is applied with a thickness of 1 to 100 μm. Preferably, it is applied with a thickness of 1 to 50 μm, particularly preferably with a thickness of 1 to 10 μm.

  The surface of the transfer film 20 on the side of the heat sealant is placed on the partition wall 12, and only the weight of the transfer film 20 is applied to the heat sealant or while receiving a predetermined pressing force. Heated to a temperature exceeding the softening temperature (heat bonding: thermal transfer). Thereafter, when the transfer film 20 is peeled off, the heat sealant 22 remains in a state of being thermally transferred onto the partition wall 12.

  The pressing force here is preferably 0.01 to 0.7 MPa, and particularly preferably 0.1 to 0.4 MPa.

  In addition, as long as the effect of the present invention is exhibited, the heat sealant 22 may be thermally transferred onto all the partition walls 12, or the heat sealant 22 may be thermally transferred only onto some of the partition walls 12. For example, the heat sealant 22 may be thermally transferred only onto the peripheral partition wall 12.

  Returning to FIG. 6, after the adhesive layer (= heat sealant) 22 is formed, each region partitioned by the partition wall 12 and the adhesive layer 22 is filled with ink 13 as a display medium (display medium (ink ) Filling step). Here, (1) the ink 13 is dropped from the dispenser 31 (or inkjet, die coat), and (2) the ink 13 is applied by the central squeegee (or doctor blade, doctor knife) 32 so as to be in-plane uniform, 3) Further, the excess ink that protrudes is scraped off by both-end squeegees (or doctor blade, doctor knife, material is urethane rubber, silicon rubber, synthetic rubber, metal, plastic, etc.) 33a, 33b. (4) Finally, wiper 34 As a result, excess ink collected on one side is wiped off.

  FIG. 8 is a diagram schematically showing the final stage of the manufacturing method of the electrophoretic display device according to the present embodiment. As shown in FIG. 8, a conductive paste application step is performed after the ink filling step. The conductive paste 14 is a metal paste such as a silver paste, and is applied to a predetermined position by, for example, a dispenser 41 (or ink jet, tampo printing, pad printing, or stacking printing). As shown in FIG. 9, the conductive paste 14 functions as a wiring for applying a voltage to the other substrate 16 (front plane base material: FP) described later.

  Thereafter, as shown in FIG. 8, the other substrate 16 facing the one substrate 11 is bonded onto the adhesive layer 22 on the partition wall 12 (substrate bonding step). Thereby, each upper surface of a some cell is prescribed | regulated and a display medium (ink 13) is sealed in each cell. Here, in the substrate bonding step, the adhesive force is obtained by heating to a temperature exceeding the temperature at which the heat sealant 22 using the thermoplastic material transferred as the adhesive layer is softened. Specifically, in a state where only the weight of the other substrate 16 is applied, or while receiving a predetermined laminating pressure, it is heated and softened from the periphery to a temperature exceeding the temperature at which the heat sealing agent 22 softens, and the partition wall 12 is softened. And upper substrate 16 are firmly bonded.

  Thereafter, as shown in FIG. 8, the sheet is cut into a predetermined size by a cutting device 51 such as a guillotine, an upper blade sliding device, a laser cutting device, or a laser cutter, and further subjected to outer periphery sealing processing to obtain a desired electric power. Manufacturing of the electrophoretic display device is completed.

  According to the present embodiment, high display quality can be maintained because the cell arrangement pattern and the electrode arrangement pattern are different. On the other hand, by providing the electrode boundary partition wall 12b on the substrate in the portion where the electrode 11a is not formed, the uneven distribution of the electrophoretic body can be effectively suppressed, and as a result, high display quality can be obtained.

  In addition, according to the present embodiment, by using the heat sealant 22 using a thermoplastic material as an adhesive, the partition 12 and the other substrate 16 can be reliably bonded to each other with a simple process. In addition, by using the transfer film 20 when the heat sealant 22 is thermally transferred, high-precision alignment on the partition wall 12 is unnecessary, but the heat seal agent 22 can be reliably thermally transferred only to the upper surface of the partition wall 12.

  In addition, the heat sealant 22 using a thermoplastic material thermally transferred as an adhesive layer has no tack (stickiness) at room temperature, and is very convenient to handle. Further, since there is no tack (stickiness), the subsequent display medium filling process is easy. Specifically, even if the display medium is filled with a squeegee (or doctor blade, doctor knife) or the like, the display medium (ink 13) does not adhere to the heat sealant 22.

  Since the other substrate 16 is securely bonded to the partition wall 12 by heating the heat sealant 22, the bonded portion does not peel even when the other substrate 16 is deformed. There are no gaps that would undesirably move. Further, since there is no possibility of impurities entering the cell when the other substrate 16 is bonded, there is no risk of deterioration in display quality. Since the heat sealant 22 after the other substrate 16 is bonded does not have tack (stickiness) at room temperature, the display medium does not adhere to the heat sealant 22, and display quality is also observed in this respect. There is no risk of deterioration.

  Next, an example actually performed to confirm that there is no deterioration in display quality will be described.

  One substrate 11 of this example was a polyethylene terephthalate (PET) film (manufactured by Teijin DuPont) having a thickness of 100 μm, and an electrode 11a as a Cu electrode was formed in a lattice pattern.

  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 30 μm, prebaked at 100 ° C. for 1 minute, and then exposed. The barrier ribs 12 are formed by performing exposure using a mask (exposure amount: 500 mJ / cm 2), followed by spray development using a 1% KOH aqueous solution for 30 seconds, and post baking at 200 ° C. for 60 minutes. It was. The formed partition walls 12 are an electrode boundary partition wall 12a having a grid pattern (line width: 100 μm) with a width to fill the gap of the electrode 11a, and a cell boundary partition wall 12b having a honeycomb pattern (line width: 35 μm) with an opening of 90%. And consisted of. The line width of the partition wall 12 was measured by measuring the line width on the upper surface of the partition wall 12 using a two-dimensional coordinate measuring device (manufactured by Sokkia).

  A polyethylene terephthalate (PET) film (manufactured by Teijin DuPont) having a thickness of 50 μm is used as the transfer film substrate 21, and a heat seal agent 22 (Byron UR1400, manufactured by Toyobo Co., Ltd.) using a thermoplastic material is used as the die coater. Applied and dried. Thus, a roll-shaped transfer film 20 having a 10 μm adhesive layer 22 was produced.

  Then, in a state where the transfer film 20 is placed on the upper surface of the partition wall 12, while further applying a predetermined pressing force, the temperature around the heat seal agent 22 exceeds the temperature at which the heat seal agent 22 softens, for example, about 100 degrees. As a result, the heat sealant 22 was thermally transferred onto the partition wall 12.

  The thickness of the heat sealant 22 was 10 μm. The partition wall 12 had a thickness of 29 μm.

  Subsequently, an ink 13 having the following components is used as a display medium, dropped from the dispenser 31, and squeezed with a central squeegee 32 (Neurong squeegee 1: made of urethane resin), and in each cell. Filled. Excess ink that protruded in the substrate width direction was scraped off by another squeegee 33a, 33b (Nelogue Squeegee 2: made of urethane resin), and further wiped off by a roll wiper 34.

<Ink component>
・ Electrophoretic particles (titanium dioxide): 60 parts by weight ・ Dispersion liquid: 40 parts by weight Subsequently, a silver paste (manufactured by Fujikura Kasei) is dispensed on a part of the outer periphery of the pattern (square area of 2 mm × 2 mm). Spot application by 41.

  Next, an indium tin oxide (ITO) vapor deposition film (thickness 0.2 μm) is provided as a transparent electrode on one surface of a 100 μm thick polyethylene terephthalate (PET) film (manufactured by Teijin DuPont) as the other substrate 16. The obtained electrode substrate was used and placed on the adhesive layer 22. Then, the surroundings of the adhesive layer (heat seal agent) 22 are heated to about 100 degrees while further applying a predetermined pressing force under atmospheric pressure (normal pressure atmosphere). As a result, the adhesive layer 22 is The partition wall 12 and the other substrate 16 were firmly bonded. As the transparent electrode of the substrate, indium tin oxide (ITO), zinc oxide (ZnO), tin oxide (SnO), or the like is formed by a general film forming method such as sputtering, vacuum evaporation, or CVD. .

  The pressing force here is preferably 0.01 to 0.7 MPa, and particularly preferably 0.1 to 0.4 MPa.

  After that, it is cut into a predetermined size, and an ultraviolet curable resin (LCB-610, manufactured by EACH Sea Co., Ltd.) is applied around the two electrode substrates 11 and 16 using a dispenser (not shown). And then cured by exposure to ultraviolet rays (exposure amount 700 mJ / cm 2) (peripheral sealing treatment).

  With respect to the electrophoretic display device obtained as described above, the contrast after applying a DC voltage of 80 V between the upper and lower electrodes was observed, but it was very good.

  Next, materials and characteristics of each member of the electrophoretic display device as a manufacturing object of the present invention will be described in more detail.

  As the substrate 11, a substrate in which an electrode 11 a is formed of a conductive material such as a metal on the surface of a resin film, a resin plate, glass, epoxy glass (glass epoxy), ceramics, or the like can be used. Alternatively, a metal plate or a light transmissive substrate may be used. As an opaque base material, an opaque glass base material having a rough surface on the other surface different from the electrode surface, an opaque base material with a metal film deposited on the other surface different from the electrode surface, dyes and pigments An opaque resin base material kneaded with can be used.

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

  The surface of one substrate 11 may be subjected to an oxidation preventing process by a plating process. Further, a barrier layer may be provided on the back surface (outside) of one substrate 11. The function of the barrier layer is to prevent display deterioration caused by the ink adsorbing moisture. The barrier layer is obtained by vapor-depositing an inorganic film (the other substrate 16 may be transparent and the other substrate 11 may be transparent or opaque). Or the film in which the barrier layer was previously formed may be bonded together. The formation of the electrode 11a on one substrate 11 can be performed by a photolithography method, a laser drawing method, an ink jet method, a screen printing method, a flexographic printing method, or the like. A TFT substrate may be used as the one substrate 11.

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

  The partition wall 12 can be made of an ultraviolet curable resin, a thermosetting resin, a room temperature curable resin, or the like, and is preferably formed to a thickness of 5 to 100 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 (contrast) cannot be obtained. On the other hand, if the thickness is 100 μm or more, the panel is too thick and the drive voltage is excessively increased. From the viewpoint that good display characteristics can be obtained at a low driving voltage, a thickness in the range of 10 to 50 μm is preferable.

  The opening ratio of the partition wall 12 is preferably 60% or more, more 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.

  In addition to the photolithography method, a mold transfer (embossing) method can be adopted as a method for forming the partition wall 12. Furthermore, a method of manufacturing a mesh-processed structure as a partition and sticking the structure to one substrate 11 may be employed.

  As the heat sealant 22, a material using a thermoplastic material is preferable. It has a property of being softened by heating and solidifying when cooled, and the plasticity is reversibly maintained when cooling and heating are repeated. Material. Specifically, polyester resins (amorphous and crystalline) that are thermoplastic resins, polyamide resins, amorphous styrene acrylic / polyester resins, crystalline polyurethane resins, aqueous (polyolefin resin emulsion) resins, etc. Can be used.

  The temperature at which the heat sealing agent 22 is softened may be the glass transition temperature (Tg) or the melting temperature (Tm) of the heat sealing agent 22 depending on the type of the heat sealing agent 22, and is preferably 150 ° C. or lower, more preferably 120 ° C. or lower. 80 ° C. or lower is particularly preferable. In particular, if the temperature at which the heat sealing agent 22 softens is higher than the glass transition temperature of the base films 11 and 16, the base films 11 and 16 may shrink and wrinkles may occur, which is not preferable. Further, the thermal decomposition temperature of the ink 13 (here, the thermal decomposition means that the chemical properties (modes) of the ink 13 change due to volatilization of the solvent, additives, particles, etc. contained in the ink 13 by heating. If the temperature at which the heat sealant 22 softens is higher than that of the heat sealant 22, the display performance may be deteriorated due to thermal decomposition of the ink 13.

  As described above, the heat sealing agent 22 is preferably formed to a thickness of 1 to 100 μm. If it is 1 μm or less, sufficient adhesion performance cannot be obtained. On the other hand, when the thickness is 100 μm or more, the thickness of the panel is too thick, and the drive voltage increases too much. From the viewpoint of good adhesion and good display characteristics at a low driving voltage, a thickness in the range of 1 to 50 μm is preferable, and a thickness in the range of 1 to 10 μm is particularly preferable.

  In order to improve the adhesion between the partition wall 12 and the heat sealant 22, the partition wall 12 may be subjected to surface treatment (such as ultraviolet irradiation or plasma treatment), or a primer may be formed. Alternatively, a silane coupling agent may be added to the heat sealing agent 22.

  Various known materials can be used for the display medium (ink 13).

  As the other substrate 16, a transparent film such as PE, PET, PES, PEN or the like provided with a transparent electrode such as ITO or ZnO can be typically used. The transparent electrode can be formed by a coating method, a vapor deposition method, or the like.

  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 a panel cannot be obtained and the risk of breakage increases. On the other hand, if it is thicker than 1 mm, the panel weight becomes too heavy and the handling becomes inconvenient and the cost also increases. Because. A suitable thickness range that is difficult to break and easy to handle is about 50 μm to 300 mm.

  Further functional layers can be added to the other substrate 16. For example, a barrier film can be attached to the surface of the other substrate 16. Even if a transparent film in which a barrier layer of a transparent inorganic film is previously formed by vapor deposition or the like is employed as the other substrate 16, the same function as this can be exhibited. Alternatively, an ultraviolet cut film can be attached to the surface of the other substrate 16. Even if the other substrate 16 is subjected to other ultraviolet cut processing, the same function can be exhibited. As other surface coat layers, an AG layer (antiglare layer), an HC layer (scratch prevention layer), an AR layer (antireflection layer) and the like can be added.

  The other substrate 16 can be applied in either a roll shape or a sheet shape.

  The peripheral sealant can be constituted by a thermosetting resin, a room temperature curable resin, a heat seal resin, or the like in addition to the ultraviolet curable resin. They are applied to the periphery of the two electrode substrates 11 and 16 by a dispenser, by various printing methods, or by thermocompression bonding.

11 One substrate (backplane base material)
11a electrode 12 partition 12a electrode boundary partition 12b cell boundary partition 13 ink (display medium)
16 Other board (front plane base material)
20 Transfer film 21 Transfer film substrate 22 Heat seal agent (adhesive layer)
31 Dispenser 32 Central Squeegee (Squeegee 1)
33a, 33b Both-end squeegee (squeegee 2)
34 Roll wiper 41 Dispenser 51 Cutting device

Claims (7)

A plurality of cells are provided between two opposing substrates, at least one of which is transparent, and a display medium containing at least one or more electrophores is enclosed in each cell, and the two sheets A method of manufacturing an electrophoretic display device, wherein the display medium displays predetermined information when a predetermined electric field is applied between substrates,
An electrode forming step of forming a plurality of electrodes in a predetermined arrangement pattern on one substrate;
An electrode boundary partition forming step of forming an electrode boundary partition in a portion where the electrode is not formed;
A cell boundary partition forming step of forming a cell boundary partition on the one substrate or electrode in a predetermined cell arrangement pattern; and
A display medium filling step of filling the display medium with each region partitioned by the cell boundary partition as a cell,
A substrate bonding step of sealing the display medium by bonding the other substrate on the electrode boundary partition and / or the cell boundary partition;
With
The cell arrangement pattern is a circular or polygonal pattern,
The method for manufacturing an electrophoretic display device, wherein the electrode arrangement pattern is different from the cell arrangement pattern. 2. The method of manufacturing an electrophoretic display device according to claim 1, wherein the line width of the cell boundary partition is formed narrower than the line width of the electrode boundary partition. 3. The method for manufacturing an electrophoretic display device according to claim 1, wherein the cell arrangement pattern is a honeycomb pattern. An adhesive layer forming step of forming an adhesive layer on the electrode boundary partition and / or the cell boundary partition;
The adhesive layer forming step is performed by thermally transferring the heat sealant using a transfer substrate on which a heat sealant using a thermoplastic material is formed,
The display medium filling step is performed after the adhesive layer is formed,
The substrate bonding step includes a heating step in which the heat sealant transferred as an adhesive layer is softened again to obtain an adhesive force, and the other side of the electrode boundary partition and / or the cell boundary partition on the adhesive layer. 4. The method of manufacturing an electrophoretic display device according to claim 1, wherein the display medium is sealed by bonding a substrate. A plurality of cells are provided between two opposing substrates, at least one of which is transparent, and a display medium containing at least one or more electrophores is enclosed in each cell, and the two sheets An electrophoretic display device in which the display medium displays predetermined information when a predetermined electric field is applied between substrates,
Electrodes arranged in a predetermined pattern on one substrate;
An electrode boundary partition disposed in a portion where the electrode is not formed;
A cell boundary partition arranged in a predetermined cell arrangement pattern on the one substrate or electrode;
Each region defined by the cell boundary partition walls is a cell, and the display medium is included in the cell.
The cell arrangement pattern is a circular or polygonal pattern,
2. The electrophoretic display device according to claim 1, wherein the electrode arrangement pattern is different from the cell arrangement pattern. 6. The electrophoretic display device according to claim 5, wherein the line width of the cell boundary partition is narrower than the line width of the electrode boundary partition. The electrophoretic display device according to claim 5, wherein the cell arrangement pattern is a honeycomb pattern.

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