JP2011237708A - Electrophoresis display device, manufacturing method of the same and electronic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophoresis display device capable of reliably sealing an electrophoresis layer while improving the quality of display, and further to provide a manufacturing method of the electrophoresis display device and an electronic equipment.SOLUTION: An electrophoresis display device includes: a first substrate 31 and a second substrate 41 oppositely disposed to each other; an electrophoresis layer 33 interposed between the first substrate 31 and the second substrate 41; pixel electrodes 21 interposed between the first substrate 31 and the electrophoresis layer 33; a common electrode 22 interposed between the second substrate 41 and the electrophoresis layer 33; and partitions 35 for partitioning the electrophoresis layer 33 into each cell region. A second insulating layer 42 containing components similar or identical to main components of which the partitions 35 are composed is disposed on a surface of the second substrate 41 opposite to the partitions 35 through the common electrode 22.

Description

  The present invention relates to an electrophoretic display device, a method for manufacturing an electrophoretic display device, and an electronic apparatus.

  As the electrophoretic display device, one having a configuration in which a pair of substrates is partitioned into a plurality of spaces by partition walls and an electrophoretic dispersion liquid containing electrophoretic particles and a dispersion medium is sealed in each space is known.

  As a method for manufacturing the electrophoretic display device, a partition wall is formed on one substrate, and then an electrophoretic dispersion is placed in the space surrounded by the partition wall. Next, the whole on one substrate is sealed. As a sealing method, for example, one substrate and the other substrate are bonded using an adhesive, or electrophoretic dispersion injected into a region partitioned by a partition as described in Patent Document 1. A method is known in which a liquid that is incompatible with the electrophoretic dispersion liquid and cured by light, heat, or drying is applied onto both the liquid and the partition walls, and then cured and sealed as a top plate.

JP-A-2005-1079

  However, when dissolved in the dispersion medium, for example, there is a problem that the dispersibility of the electrophoretic particles is adversely affected. Thereby, the subject that the said adhesive agent and the said liquid for sealing are limited to the material which does not melt | dissolve in a dispersion medium occurs.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 An electrophoretic display device according to this application example includes a first substrate and a second substrate which are disposed to face each other, and an electrophoretic layer provided between the first substrate and the second substrate. A plurality of electrophoretic layers, a first electrode provided between the first substrate and the electrophoretic layer, a second electrode provided between the second substrate and the electrophoretic layer, and And an insulating layer including a component similar to the main component of the partition wall is provided on a surface of the second substrate in contact with the partition wall.

  According to this configuration, since the partition wall and the insulating layer (sealing layer) are composed of insulating layers containing similar main components, adhesion between the partition wall and the insulating layer can be improved without using an adhesive or the like. Can be improved. Therefore, it is possible to prevent the adhesive from being dissolved in the dispersion medium constituting the electrophoretic layer and adversely affecting the dispersibility of the electrophoretic particles as in the case of using an adhesive or the like.

  Application Example 2 In the electrophoretic display device according to the application example, it is preferable that the partition walls and the insulating layer have the same main component.

  According to this configuration, since the main components of the partition and the insulating layer are the same, the adhesion between the partition and the insulating layer can be improved.

  Application Example 3 In the electrophoretic display device according to the application example, it is preferable that the partition includes an olefin resin material as a main component.

  According to this structure, it becomes possible to weld an insulating layer and a partition, and can improve the adhesiveness of an insulating layer and a partition.

  Application Example 4 In the electrophoretic display device according to the application example described above, it is preferable that the insulating layer is in contact with the partition and has a larger planar area than the partition.

  According to this configuration, since the insulating layer has a larger planar area than the partition wall, the adhesion of the partition wall to the insulating layer can be improved. Therefore, the adhesion between the partition walls and the insulating layer can be improved without using an adhesive or the like. That is, the partition wall can be sealed.

  Application Example 5 In the electrophoretic display device according to the application example described above, the insulating layer includes at least the second electrode in one of the plurality of cells between the second electrode and the electrophoretic layer. It is preferable that it is provided so as to cover.

  According to this configuration, since the insulating layer is provided so as to cover the second electrode in one cell, it is possible to prevent the second electrode and the electrophoretic layer from directly contacting each other. Therefore, the electrophoretic particles contained in the electrophoretic layer can be easily moved by the electric field generated between the first electrode and the second electrode without adhering to the second electrode.

  Application Example 6 In the electrophoretic display device according to the application example, it is preferable that the insulating layer has a thickness of 100 nm to 100 μm.

  According to this configuration, by setting the thickness of the insulating layer as described above, it can function as an insulating film, and an effective voltage in an appropriate range can be applied to the electrophoretic layer. In addition, it is preferable that it is 10 micrometers-50 micrometers in the thickness of an insulating layer. According to this, adhesiveness (adhesion strength) with a partition can be improved.

  Application Example 7 In the electrophoretic display device according to the application example, it is preferable that the first electrode is a pixel electrode, and one of the plurality of cells is provided with a plurality of the first electrodes. .

  According to this configuration, since one cell includes a plurality of pixel electrodes, for example, the configuration of the partition walls can be simplified even if the pixel electrodes are provided with high definition.

  [Application Example 8] A method for manufacturing an electrophoretic display device according to this application example is provided between a first substrate and a second substrate which are arranged to face each other, and between the first substrate and the second substrate. An electrophoresis layer, a first electrode provided between the first substrate and the electrophoresis layer, a second electrode provided between the second substrate and the electrophoresis layer, and the electrophoresis And a partition provided on the first substrate for dividing the layer into a plurality of cells, wherein the main component of the partition is formed on a surface of the second substrate in contact with the partition. An insulating layer forming step of forming an insulating layer containing a component similar to the above, and an adhering step of arranging the first substrate and the second substrate facing each other and bonding the partition and the insulating layer to each other It is characterized by that.

  According to this method, since the partition and the insulating layer (sealing layer) are formed of an insulating material containing similar main components, the adhesion between the partition and the insulating layer can be improved without using an adhesive or the like. Can be improved. Therefore, it is possible to prevent the adhesive from being dissolved in the dispersion medium constituting the electrophoretic layer and adversely affecting the dispersibility of the electrophoretic particles, as in the case of using an adhesive or the like.

  Application Example 9 In the method for manufacturing an electrophoretic display device according to the application example, the partition is formed of a first photosensitive material, and the insulating layer forming step is a component similar to the main component of the partition. The insulating layer is formed using a second photosensitive material containing, and in the bonding step, the partition wall and the insulating layer are brought into contact with each other, and then the partition wall and the insulating layer are heated to form a resin. It is preferable to have a resinification step.

  According to this method, since heat is applied to the partition walls and the insulating layer (for example, post-baking treatment) to form a resin, the adhesion between the insulating layer and the partition walls can be improved.

  Application Example 10 In the method for manufacturing an electrophoretic display device according to the application example described above, it is preferable that the resinification step is heated from both the first substrate and the second substrate.

  According to this method, since heating is performed from both substrates (first substrate and second substrate), heat can be uniformly applied to the partition walls and the insulating layer. Therefore, the partition walls and the insulating layer can be uniformly made into resin, and the adhesion can be improved.

  Application Example 11 In the method for manufacturing an electrophoretic display device according to the application example, it is preferable that the partition wall includes an olefin resin material as a main component.

  According to this method, since the insulating material containing the olefin-based resin material is used, for example, by applying heat, the insulating layer and the partition wall can be welded, and the adhesion can be improved.

  Application Example 12 In the method for manufacturing an electrophoretic display device according to the application example, it is preferable that the insulating layer forming step forms the insulating layer so as to cover at least the second electrode.

  According to this method, since the insulating layer is provided so as to cover the second electrode in one cell, it is possible to prevent the second electrode and the electrophoretic layer from directly contacting each other. Therefore, the electrophoretic particles contained in the electrophoretic layer can be easily moved by the electric field generated between the first electrode and the second electrode without adhering to the second electrode.

  Application Example 13 An electronic apparatus according to this application example includes the electrophoretic display device described above.

  According to this configuration, since the electrophoretic display device described above is provided, it is possible to provide an electronic apparatus in which the dispersibility of the electrophoretic particles is prevented from being lowered and stable display quality can be obtained.

FIG. 3 is an equivalent circuit diagram illustrating an electrical configuration of the electrophoretic display device. FIG. 3 is a schematic cross-sectional view illustrating a structure of an electrophoretic display device. FIG. 3 is a schematic plan view of the electrophoretic display device shown in FIG. 2 viewed from above. The flowchart which shows the manufacturing method of an electrophoretic display device in order of a process. FIG. 6 is a schematic cross-sectional view illustrating a part of the manufacturing method of the electrophoretic display device. FIG. 6 is a schematic cross-sectional view illustrating a part of the manufacturing method of the electrophoretic display device. FIG. 6 is a schematic cross-sectional view illustrating a part of the manufacturing method of the electrophoretic display device. The chart which shows the relationship between the thickness of an insulating layer, and adhesive strength. The perspective view which shows typically the structure of electronic paper as an example of the electronic device provided with the electrophoretic display apparatus. FIG. 9 is a schematic cross-sectional view illustrating a structure of an electrophoretic display device that is a modified example.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings. Note that the drawings to be used are appropriately enlarged or reduced so that the part to be described can be recognized.

  In the following embodiments, “upper” indicates the direction in which the electrophoretic layer is disposed when viewed from the substrate. When “above” is described, it is disposed so as to be in contact with XX. Or when placed on XX via other components, or placed partially on XX and partly placed via other components Shall.

<Configuration of electrophoretic display device>
FIG. 1 is an equivalent circuit diagram showing an electrical configuration of the electrophoretic display device. Hereinafter, the electrical configuration of the electrophoretic display device will be described with reference to FIG.

  As shown in FIG. 1, the electrophoretic display device 11 includes a plurality of data lines 12 and a plurality of scanning lines 13, and pixels 14 are arranged at portions where the data lines 12 and the scanning lines 13 intersect. . Specifically, the electrophoretic display device 11 has a plurality of pixels 14 arranged in a matrix along the data lines 12 and the scanning lines 13. Each pixel 14 has a dispersion liquid 15 containing electrophoretic particles disposed between a pixel electrode 21 as a first electrode and a common electrode 22 as a second electrode.

  The pixel electrode 21 is connected to the data line 12 via the transistor 16. The gate electrode of the transistor 16 is connected to the scanning line 13. Note that FIG. 1 is an example, and other elements such as a storage capacitor may be incorporated as necessary.

  FIG. 2 is a schematic cross-sectional view showing the structure of the electrophoretic display device. FIG. 3 is a schematic plan view of the electrophoretic display device shown in FIG. 2 as viewed from above (opposite substrate side). Hereinafter, the structure of the electrophoretic display device will be described with reference to FIGS.

  As shown in FIG. 2, the electrophoretic display device 11 includes an element substrate 51, a counter substrate 52, and an electrophoretic layer 33. A pixel electrode 21 is disposed for each pixel 14 on a first substrate 31 that constitutes the element substrate 51 and is made of, for example, a transparent glass substrate. More specifically, as shown in FIG. 3, the pixels 14 (pixel electrodes 21) are formed in a matrix in a plane. As a material of the pixel electrode 21, for example, a light transmissive material such as ITO (Indium Tin Oxide added with tin) is used.

  A circuit unit (not shown) is provided between the first substrate 31 and the pixel electrode 21, and the transistor 16 and the like are formed in the circuit unit. The transistor 16 is electrically connected to each pixel electrode 21 through a contact portion (not shown). Although not shown, in the circuit portion, in addition to the transistor 16, various wirings (for example, the data line 12 and the scanning line 13) and elements (for example, capacitive elements) are arranged. A first insulating layer 32 is formed on the entire surface of the first substrate 31 including the pixel electrode 21.

  A common electrode 22 that is common to the plurality of pixels 14 is formed on the second substrate 41 that constitutes the counter substrate 52 and is made of, for example, a light-transmitting glass substrate. As the common electrode 22, for example, a light transmissive material such as ITO is used. A second insulating layer 42 (insulating layer) including a component similar to the main component of the material of the partition wall 35 is formed on the common electrode 22. Or the material and the main component of the partition 35 are the same.

  An electrophoretic layer 33 is provided between the first insulating layer 32 and the second insulating layer 42. The dispersion liquid 15 of the electrophoretic particles 34 constituting the electrophoretic layer 33 is filled in a space formed by the first insulating layer 32, the second insulating layer 42, and the partition walls 35. For example, as shown in FIG. 3, the partition walls 35 are arranged in a grid pattern and partition each pixel 14. In addition, it is preferable that the partition 35 is a translucent material.

  2 and 3, white particles and black particles are shown as the electrophoretic particles 34. For example, when a voltage is applied between the pixel electrode 21 and the common electrode 22, the electrophoretic particles 34 are electrophoresed toward one of the electrodes (the pixel electrode 21 and the common electrode 22) according to the electric field generated between them. To do. For example, when the white particles have a positive charge, if the pixel electrode 21 is set to a negative potential, the white particles move to the pixel electrode 21 side (lower side) and gather to display black.

  Conversely, when the pixel electrode 21 is set to a positive potential, the white particles move to the common electrode 22 side (upper side) and gather to display white. In this manner, desired information (image) is displayed according to the presence or absence or the number of white particles gathering on the display-side electrode. Here, although white particles or black particles are used as the electrophoretic particles 34, other colored particles may be used.

  Further, as the electrophoretic particles 34, inorganic pigment-based particles, organic pigment-based particles, polymer fine particles, or the like can be used, and two or more kinds of various particles may be mixed and used. The diameter of the electrophoretic particles 34 is, for example, about 0.05 μm to 10 μm, and preferably about 0.2 μm to 2 μm.

  Moreover, the ratio with respect to the dispersion liquid 15 is adjusted to about 5 wt% to 90 wt%, for example, and preferably adjusted to about 10 wt% to 80 wt%. Although there is no restriction | limiting in the dispersion medium which comprises the dispersion liquid 15, For example, aliphatic hydrocarbons, halogenated hydrocarbons, phosphoric acid, such as aromatic hydrocarbons, hexane, cyclohexane, kerosene, isopar, and paraffin hydrocarbons Esters, phthalic acid esters, carboxylic acid esters, chlorinated paraffin, silicones and the like can be used.

  The ratio of the dispersion medium to the dispersion liquid 15 is adjusted to, for example, about 20 wt% to 90 wt%, and preferably adjusted to about 40 wt% to 60 wt%. In addition to the dispersion medium, for example, various additives such as a charge control agent composed of an electrolyte, a surfactant, a lubricant, and a stabilizer may be added to the dispersion 15 as necessary. Various dyes may be dissolved.

  Hereinafter, the liquid portion other than the electrophoretic particles 34 in the dispersion 15 is referred to as a “dispersion medium”. A region surrounded by the partition walls 35 in a plan view is called a cell 36. One cell 36 includes a pixel electrode 21, a common electrode 22, and an electrophoretic layer 33.

  As described above, since the partition wall 35 and the second insulating layer 42 are made of the same main component material, the adhesion between the partition wall 35 and the second insulating layer 42 can be improved. That is, the element substrate 51 and the counter substrate 52 are bonded (bonded) when the partition wall 35 and the second insulating layer 42 are in close contact with each other, and the electrophoretic layer 33 provided on the element substrate 51 is sealed by the counter substrate 52. can do. Hereinafter, a method for manufacturing the electrophoretic display device 11 will be described.

<Method for Manufacturing Electrophoretic Display Device>
FIG. 4 is a flowchart showing a method of manufacturing the electrophoretic display device in the order of steps. 5 to 7 are schematic cross-sectional views illustrating some steps in the method of manufacturing the electrophoretic display device. Hereinafter, a method for manufacturing the electrophoretic display device will be described with reference to FIGS.

  First, a manufacturing method on the element substrate 51 side will be described. In step S11, the pixel electrode 21 made of a light transmissive material such as ITO is formed on the first substrate 31 made of a light transmissive material such as glass. Specifically, the pixel electrode 21, the wiring, and the like are formed on the first substrate 31 using a well-known film formation technique, photolithography technique, and etching technique. In the following description using the sectional views, description and illustration of the pixel electrode 21 and the like are omitted.

  In step S12 (see FIG. 5A), a first resist film 32a (first photosensitive material) to be the first insulating layer 32 containing an insulating material as a main component is applied on the first substrate 31. The application method is, for example, a spin coating method. The first resist film 32a is a negative resist film. The thickness of the first resist film 32a to be applied is 600 nm, for example. The viscosity of the first resist film 32a is, for example, 100 cp.

  The material of the first resist film 32a includes an olefin resin material. Other resin materials include, but are not limited to, for example, acrylate, methacrylate, cyanoacrylate, epoxy, paraffin, vinyl acetate, urethane, ionomer, elastomer, silicone, fluorine, and other monomers and oligomers. And polymers.

  Next, in the step (step S13) shown in FIG. 5B, a pre-baking process is performed on the applied first resist film 32a. Specific treatment conditions are as follows: the heating temperature is 60 ° C., and the heating time is 5 minutes. Furthermore, as the second time, the heating temperature is 90 ° C. and the heating time is 30 minutes. As a heating method, for example, a hot plate 43 is used.

  As described above, the first resist film 32a is subjected to heat treatment (pre-bake treatment) in two stages, so that not only the surface of the first resist film 32a but also the entire film is uniformly cured, and after the pre-bake treatment. The cured first resist film 32b can be obtained.

  Next, in the step shown in FIG. 5C (step S14), the entire surface of the first resist film 32b subjected to the pre-baking process is exposed. By exposing the negative first resist film 32b to light, the first resist film 32c is cured.

  Next, in the step shown in FIG. 5D (step S15), the first resist film 32c is baked to form an insulating layer precursor film 32d that is a stage before the first insulating layer 32. The baking conditions are a heating temperature of 90 ° C. and a heating time of 5 minutes.

  Next, in the step shown in FIG. 6E (step S21), a second resist film 35a to be a partition wall 35 is applied on the insulating layer precursor film 32d. The material of the second resist film 35a is, for example, the same as that of the first resist film 32a described above (assuming that the main components are similar). The thickness of the second resist film 35a to be applied is, for example, 45 μm to 50 μm. The viscosity of the second resist film 35a is, for example, 2000 cp.

  Next, in the step shown in FIG. 6F (step S22), the second resist film 35a is pre-baked. As specific treatment conditions, as the first time, the heating temperature is 60 ° C., and the heating time is 5 minutes. Furthermore, as the second time, the heating temperature is 90 ° C. and the heating time is 30 minutes. As a heating method, a hot plate 43 is used. Thereby, the entire second resist film 35b is cured.

  Next, in the step (step S23) shown in FIG. 6G, the second resist film 35b is exposed. Specifically, the second resist film 35c is patterned by exposing along the shape of the partition wall 35 using a mask.

  Next, in the step (step S24) shown in FIG. 6H, the second resist film 35c is baked. The baking conditions are a heating temperature of 90 ° C. and a heating time of 5 minutes. Thereby, the second resist film 35d, which is a stage before development, is formed.

  Next, in the step (step S25) shown in FIG. 7I, the second resist film 35d is developed. Thereby, a partition wall precursor film 35e having the shape of the partition wall 35 is formed from the second resist film 35d. The height of the partition wall precursor film 35e after development is, for example, 5 μm to 100 μm. In addition, it is preferable that it is 20 micrometers-60 micrometers from the point of the mobility of electrophoretic particle 34 and a display characteristic. Here, the height of the partition wall precursor film 35e (partition wall) is, for example, 45 μm. Further, since the insulating layer precursor film 32d is exposed in the process shown in FIG. 5C, the film is cured. Therefore, even if development is performed, the insulating layer precursor film 32d remains in that state.

  Next, in the step shown in FIG. 7J (step S26), the insulating layer precursor film 32d and the partition wall precursor film 35e are subjected to a post-bake treatment to form the insulating layer precursor film 32d and the partition wall precursor film 35e. Resin. As conditions for the post-bake treatment, for example, the heating temperature is 210 ° C. and the heating time is 60 minutes. Thereby, the resin-made first insulating layer 32 and the partition wall 35 are completed. The rib width of the partition wall 35 is, for example, 20 μm. By performing the post-bake treatment, the adhesion between the first insulating layer 32 and the partition wall 35 can be improved. Thus, the element substrate 51 side is completed.

  Next, a manufacturing method on the counter substrate 52 side will be described with reference to FIGS. 4 and 7 (k). In step S <b> 31, the common electrode 22 is formed on the second substrate 41. Specifically, the common electrode 22 is formed on the entire surface of the second substrate 41 made of a translucent material such as a glass substrate by using a well-known film forming technique.

  In step S <b> 32 (insulating layer forming step), the second insulating layer 42 is formed on the common electrode 22. The thickness of the second insulating layer 42 is, for example, 20 μm. The thickness of the second insulating layer 42 is, for example, 100 nm to 100 μm. Furthermore, from the viewpoint of the function as the second insulating layer 42 and the allowable range of the effective voltage applied to the electrophoretic layer 33, the thickness is preferably 10 μm to 50 μm.

  As the material of the second insulating layer 42, a material (second photosensitive material) containing a component similar to the main component of the first resist film 32a is used. Of course, the second photosensitive material and the first photosensitive material may be the same material. The formation method of the second insulating layer 42 is the same as that of the first resist film 32a. That is, a two-stage pre-bake treatment is performed, and curing is promoted uniformly. Thus, the counter substrate 52 side is completed. Subsequently, a method of bonding the element substrate 51 and the counter substrate 52 will be described with reference to FIGS. 4 and 7L.

  First, in step S41, the dispersion liquid 15 having the electrophoretic particles 34 is injected into a region surrounded by the partition walls 35 in the element substrate 51. As a method for injecting the dispersion liquid 15, it may be injected at once to the entire surface of the substrate, or may be discharged by a predetermined amount for each pixel 14 (cell 36) using a droplet discharge method or the like.

  Examples of the electrophoretic particles 34 constituting the dispersion 15 include colored or colorless (white) inorganic pigment particles, organic pigment particles, and polymer fine particles. These are used alone or in combination of two or more. The diameter of the electrophoretic particles 34 is 0.05 μm to 10 μm, more preferably 0.2 μm to 2 μm. The ratio with respect to the dispersion 15 is preferably 5 wt% to 90 wt%, and more preferably 10 wt% to 80 wt%.

  The dispersion medium constituting the dispersion 15 includes aromatic hydrocarbons, hexane, cyclohexane, kerosene, isopar, paraffin hydrocarbons and other aliphatic hydrocarbons, halogenated hydrocarbons, phosphate esters, and phthalate esters. , Carboxylic acid esters, chlorinated paraffin, silicones and the like, but are not limited thereto. The ratio of the dispersion medium to the dispersion 15 is preferably 20 wt% to 90 wt%, and more preferably 40 wt% to 60 wt%. The thickness of the electrophoretic layer 33 is, for example, 45 μm.

  In step S42 (adhesion process, resinification process), the element substrate 51 and the counter substrate 52 are bonded (bonded). Specifically, they are bonded using a hot plate. First, the counter substrate 52 is placed on the element substrate 51 and placed on the hot plate. Further, an approximately 30 g aluminum plate (not shown) is placed on the counter substrate 52 so that heat is also applied from the counter substrate 52 side. As processing conditions, the heating temperature is 90 ° C. and the heating time is 10 minutes. As a result, the partition wall 35 and the second insulating layer 42 are made into a resin while being in close contact with each other. As described above, the space sandwiched between the element substrate 51 and the counter substrate 52 is sealed, and the electrophoretic display device 11 is completed.

  In this way, the partition wall 35 and the second insulating layer 42 are formed of the same insulating material and are bonded to each other by applying heat. Therefore, the partition wall 35 and the second insulating layer are not used without using an adhesive or the like. Adhesion with 42 can be improved. As described above, an insulating material having a similar main component may be used. Therefore, it is possible to prevent the adhesive from being dissolved in the dispersion medium constituting the electrophoretic layer 33 and adversely affecting the dispersibility of the electrophoretic particles 34 as in the case of using an adhesive or the like.

  In one cell 36, the common electrode 22 is covered with the second insulating layer 42, so that the electrophoretic particles 34 are not in direct contact with the common electrode 22. Therefore, the electrophoretic particles 34 are not attached to the common electrode 22 so that the electrophoretic particles do not move, and good electrophoresis can be obtained. Although not shown, in order to electrically connect the common electrode 22 and the drive circuit, a region where the second insulating layer 42 is not provided is provided in a region where the dispersion liquid 15 is not provided. Yes.

  FIG. 8 is a chart showing the relationship between the thickness of the insulating layer (second insulating layer) and the adhesive strength. Hereinafter, the relationship between the thickness of the insulating layer and the adhesive strength will be described with reference to FIG.

  The chart shown in FIG. 8 shows the effective voltage applied to the electrophoretic display device 11 when the thickness of the second insulating layer 42 used in the electrophoretic display device 11 is changed in five stages, and the second insulating layer 42 and the partition wall 35. Are evaluated with “◯”, “×”, and “Δ”. Here, the effective voltage is a voltage necessary for driving the electrophoretic display device 11 with a necessary contrast. The longitudinal direction for evaluating the adhesive strength is, for example, the direction of the force applied so as to peel off the element substrate 51 and the counter substrate 52. The lateral direction is a direction of a force applied so that the element substrate 51 and the counter substrate 52 are shifted from each other.

  As shown in FIG. 8, when the thickness of the second insulating layer 42 is 10 nm, the effective voltage applied to the electrophoretic display device 11 is 20 V, and the adhesive strength is x. Specifically, the strength in the vertical direction and the strength in the horizontal direction for evaluating the adhesive strength are both x.

  When the thickness of the second insulating layer 42 is 100 nm, the effective voltage is 30 V and the adhesive strength is Δ. In addition, the intensity | strength of a vertical direction is (triangle | delta) and the intensity | strength of a horizontal direction is (circle). When the thickness of the second insulating layer 42 is 600 nm, the effective voltage is 40 V and the adhesive strength is Δ. In addition, the intensity | strength of a vertical direction is (triangle | delta) and the intensity | strength of a horizontal direction is (circle).

  When the thickness of the second insulating layer 42 is 5 μm, the effective voltage is 40V to 60V and the adhesive strength is Δ. In addition, the intensity | strength of a vertical direction is (triangle | delta) and the intensity | strength of a horizontal direction is (circle). When the thickness of the second insulating layer 42 is 20 μm, the effective voltage is 60 V and the adhesive strength is ◯. The vertical and horizontal strengths are both ◯.

  Thus, as the thickness of the second insulating layer 42 increases, the effective voltage for driving the electrophoretic display device 11 increases. In addition, it can be seen that when the thickness of the second insulating layer 42 is increased, the adhesive strength between the element substrate 51 and the counter substrate 52 (the partition wall 35 and the second insulating layer 42) becomes good.

  However, if the second insulating layer 42 becomes thicker than the above thickness, there is a problem that the partition wall 35 enters the second insulating layer 42 and the space that becomes the electrophoretic layer 33 becomes narrow. In addition, if the material of the second insulating layer 42 is inappropriately selected, the second insulating layer 42 and the dispersion medium are mixed, or the adhesive strength between the second insulating layer 42 and the partition wall 35 is weakened. Problems arise.

  The thickness of the first insulating layer 32 is 100 nm to 100 μm, similar to the second insulating layer 42, from the viewpoint of the adhesive strength between the first insulating layer 32 and the partition wall 35 and the effective voltage. Preferably, it is further desirable that it is 10 micrometers-50 micrometers.

<Configuration of electronic equipment>
FIG. 9 is a perspective view schematically illustrating a configuration of an electronic paper (EPD) as an example of an electronic apparatus including the above-described electrophoretic display device. Hereinafter, the configuration of the electronic paper including the electrophoretic display device will be described with reference to FIG.

  As shown in FIG. 9, the electronic paper 61 includes a main body 62 composed of a rewritable sheet having the same texture and flexibility as paper, and a display unit 63. In such an electronic paper 61, the display unit 63 is configured by the electrophoretic display device 11 as described above.

  As described above in detail, according to the electrophoretic display device 11, the manufacturing method of the electrophoretic display device 11, and the electronic apparatus of the present embodiment, the following effects can be obtained.

  (1) According to the present embodiment, since the partition wall 35 and the second insulating layer 42 are made of an insulating material containing the same or similar main components, the partition wall 35 and the second insulating layer 42 are not used without using an adhesive or the like. Adhesion with the insulating layer 42 can be improved. Therefore, it is possible to prevent the adhesive from being dissolved in the dispersion liquid 15 constituting the electrophoretic layer 33 and adversely affecting the dispersibility of the electrophoretic particles 34 as in the case of using an adhesive or the like.

  (2) According to the present embodiment, since the entire surface of the common electrode 22 is covered with the second insulating layer 42, it is possible to prevent the common electrode 22 and the electrophoretic layer 33 from being in direct contact. Therefore, the electrophoretic particles 34 included in the electrophoretic layer 33 can be easily moved by the electric field generated between the pixel electrode 21 and the common electrode 22 without adhering to the common electrode 22.

  (3) According to the present embodiment, since the electrophoretic display device 11 described above is provided in the electronic paper 61, it is possible to suppress the dispersibility of the electrophoretic particles 34 from being lowered and to obtain a stable display quality. it can.

  In addition, embodiment is not limited above, It can also implement with the following forms.

(Modification 1)
As described above, the second insulating layer 42 is not limited to be provided so as to cover the common electrode 22 in one cell 36. For example, a form as shown in FIG. FIG. 10 is a schematic cross-sectional view showing the structure of the electrophoretic display device.

  In the electrophoretic display device 111 shown in FIG. 10, the second insulating layer 42 is not provided so as to cover the common electrode 22 in one cell 36, but overlaps the partition wall 35 on the second substrate 41 in plan view. The part formed only in the region and its periphery is different from the above-described embodiment.

  According to this, although the part of the common electrode 22 provided on the second substrate 41 and the electrophoretic layer 33 are in contact with each other, the partition 35 and the second insulating layer 142 are the same main component material. Therefore, the adhesion (sealing property) between the second insulating layer 142 and the partition wall 35 can be improved. Further, since the entire surface of the common electrode 22 in the cell 36 is not covered with the second insulating layer 142, the effective voltage applied to the electrophoretic layer 33 can be reduced.

(Modification 2)
As in the above-described embodiment, the partition 35 is not limited to using the photolithography method, and for example, the partition 35 and the first insulating layer 32 are formed using a halftone mask or a double patterning method. You may make it form. Specifically, the resist film is exposed to the first intensity on the portion that becomes the partition wall 35, and the resist film is exposed to the second intensity that is lower than the first intensity on a part of the resist film that becomes the first insulating layer 32. To do. Moreover, it is not limited to these methods, You may make it form by printing processes, such as a screen printing method, a relief printing method, and a gravure printing method.

(Modification 3)
As described above, the first substrate 31 and the second substrate 41 may be made of a light-transmitting material on the display side, and may be a flexible substrate made of plastic or metal in addition to a glass substrate. In the case of using plastic, for example, the temperature of the above-described post-bake treatment is lowered to about 150 ° C. and the heating time is performed for 2 to 3 hours. In this case, the electrophoretic display device 11 is preferably provided with an organic thin film transistor (organic TFT) having flexibility as a thin film transistor.

(Modification 4)
As described above, the partition wall 35 and the second insulating layer 42 are not limited to being composed of the same main component materials, and may be configured by combining similar materials as follows. For example, for acrylate, a polyolefin-based material typified by polypropylene or polyethylene may be combined. In addition, the thing which does not have a benzene ring in a composition is good. Similarly, an epoxy material may be combined with a polyolefin material typified by polypropylene or polyethylene. In addition, the thing which does not have a benzene ring in a composition is good.

(Modification 5)
As described above, the shape of the partition wall 35 is not limited to a planar lattice shape (see FIG. 3), and may be, for example, a honeycomb shape, a polygonal shape, a round shape, a triangular shape, or the like. .

(Modification 6)
As described above, the electrophoretic display device 11 is not limited to a monochrome display structure, and may have a structure capable of color display. For example, a configuration may be adopted in which a plurality of pixel electrodes 21 are included in one cell 36, and each color is displayed by inserting respective electrophoretic particles having three colors. Further, by providing the plurality of pixel electrodes 21 in one cell 36, the configuration of the partition wall 35 can be simplified and high-definition display can be performed.

  DESCRIPTION OF SYMBOLS 11,111 ... Electrophoretic display apparatus, 12 ... Data line, 13 ... Scan line, 14 ... Pixel, 15 ... Dispersion liquid, 16 ... Transistor, 21 ... Pixel electrode as 1st electrode, 22 ... Common as 2nd electrode Electrode 31 ... first substrate 32 ... first insulating layer 32a, 32b, 32c ... first resist film as first photosensitive material 32d ... insulating layer precursor film 33 ... electrophoretic layer 34 ... electricity Electrophoretic particles, 35 ... barrier ribs, 35a, 35b, 35c, 35d ... second resist film, 35e ... barrier rib precursor film, 36 ... cell, 41 ... second substrate, 42, 142 ... second insulating layer as insulating layer, DESCRIPTION OF SYMBOLS 43 ... Hot plate, 51 ... Element board | substrate, 52 ... Opposite board | substrate, 61 ... Electronic paper as an electronic device, 62 ... Main body, 63 ... Display unit.

Claims (13)

A first substrate and a second substrate disposed opposite to each other;
An electrophoretic layer provided between the first substrate and the second substrate;
A first electrode provided between the first substrate and the electrophoretic layer;
A second electrode provided between the second substrate and the electrophoretic layer;
A partition wall dividing the electrophoretic layer into a plurality of cells;
Have
An electrophoretic display device, wherein an insulating layer containing a component similar to a main component of the partition wall is provided on a surface of the second substrate in contact with the partition wall. The electrophoretic display device according to claim 1,
The electrophoretic display device, wherein the partition wall and the insulating layer have the same main component. The electrophoretic display device according to claim 1 or 2,
The partition includes an olefin resin material as a main component. An electrophoretic display device according to any one of claims 1 to 3,
The electrophoretic display device, wherein the insulating layer is in contact with the partition wall and has a larger plane area than the partition wall. An electrophoretic display device according to any one of claims 1 to 4,
The electrophoretic display, wherein the insulating layer is provided between the second electrode and the electrophoretic layer so as to cover at least the second electrode in one of the plurality of cells. apparatus. An electrophoretic display device according to any one of claims 1 to 5,
The electrophoretic display device, wherein the insulating layer has a thickness of 100 nm to 100 μm. An electrophoretic display device according to any one of claims 1 to 6,
The electrophoretic display device, wherein the first electrode is a pixel electrode, and a plurality of the first electrodes are provided in one of the plurality of cells. A first substrate and a second substrate disposed opposite to each other;
An electrophoretic layer provided between the first substrate and the second substrate;
A first electrode provided between the first substrate and the electrophoretic layer;
A second electrode provided between the second substrate and the electrophoretic layer;
A partition provided on the first substrate for dividing the electrophoretic layer into a plurality of cells;
A method for producing an electrophoretic display device comprising:
An insulating layer forming step of forming an insulating layer containing a component similar to the main component of the partition wall on a surface of the second substrate in contact with the partition wall;
An adhesion step in which the first substrate and the second substrate are arranged to face each other and the partition and the insulating layer are adhered to each other;
A method for producing an electrophoretic display device, comprising: A method for manufacturing an electrophoretic display device according to claim 8,
The partition is made of a first photosensitive material,
The insulating layer forming step forms the insulating layer using a second photosensitive material containing a component similar to the main component of the partition wall,
The method of manufacturing an electrophoretic display device, wherein the bonding step includes a resinification step in which the partition wall and the insulating layer are brought into contact with each other and then the partition wall and the insulating layer are heated to form a resin. . A method of manufacturing an electrophoretic display device according to claim 9,
The method for producing an electrophoretic display device is characterized in that the resinification step heats both the first substrate and the second substrate. A method for manufacturing an electrophoretic display device according to any one of claims 8 to 10,
The method for manufacturing an electrophoretic display device, wherein the partition wall includes an olefin resin material as a main component. A method for manufacturing an electrophoretic display device according to any one of claims 8 to 11,
In the method for manufacturing an electrophoretic display device, the insulating layer forming step forms the insulating layer so as to cover at least the second electrode.   An electronic apparatus comprising the electrophoretic display device according to claim 1.

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