HK40059722A - Display device substrate, display device, electronic apparatus, and method for manufacturing - Google Patents

Description

Substrate for display device, electronic apparatus, and method for manufacturing the same

The present application is a divisional application entitled "substrate for display device, electronic device, and method for manufacturing the same" filed on 2016, 9, 14, 9, and 201610825873.5.

Technical Field

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

Background

An electrophoretic display device in which particles having electric charges are moved in a dispersion medium is widely used. Since the screen of the electrophoretic display device has less flicker, the electrophoretic display device is applied to a display device for viewing electronic books and the like. This electrophoretic display device is disclosed in patent document 1. According to the description, the electrophoretic display device includes a pair of substrates provided with electrodes. Then, a dispersion medium containing colored charged particles is provided between the electrodes. Partition walls are provided in a lattice shape between the substrates, and spaces are partitioned by the partition walls. Also, the distance between the substrates is maintained by the partition walls.

The colored charged particles are charged in the space. Then, a voltage is applied to a pair of electrodes provided on the opposing substrates, thereby inducing colored charged particles to the one electrode. Next, the position of the colored charged particles is changed by changing the voltage of the electrode.

A pixel electrode is provided on one side of the substrate, and the pixel electrode becomes one pixel. Then, by controlling the positions of the colored charged particles in units of pixels, a predetermined pattern can be displayed.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2007-240679

Disclosure of Invention

(problems to be solved by the invention)

In patent document 1, an insulating film covered with an inorganic material is provided on a surface of one substrate. Then, a partition wall is provided on the insulating film. The material of the partition wall is fluorene ring (cardo) polymer, and is one of resin materials. After the dispersion medium is provided to the space inside the partition wall, the pair of substrates are integrated. When the pair of substrates are integrated, a load is applied between the substrates. At this time, since the partition wall and the insulating film are materials of different properties, they cannot be firmly bonded. Therefore, there is a possibility that the partition wall is peeled off from the insulating film or displaced when a load is applied to the partition wall. In this case, since the partition walls are collapsed or crushed, a substrate for a display device is desired which can suppress collapse or crushing of the partition walls even when a load is applied between the substrates.

(means for solving the problems)

The present invention has been made to solve at least the above problems, and can be realized as the following embodiments or application examples.

[ application example 1]

The present application example relates to a substrate for a display device, the substrate for a display device including: a substrate provided with an insulating layer; and a partition wall provided on the insulating layer, the insulating layer and the partition wall being formed of a resin material, the partition wall having a hardness higher than that of the insulating layer.

According to this application example, the substrate for a display device includes a substrate, and an insulating layer is provided on the substrate. Then, a partition wall is provided on the insulating layer. The insulating layer and the partition walls are formed of a resin material. Therefore, the insulating layer and the partition wall can be fixed with higher strength than when one of the insulating layer and the partition wall is made of an inorganic material. Also, the partition wall has higher hardness than the insulating layer, and thus has strength. As a result, the partition wall can be prevented from toppling or crushing even when a load is applied to the partition wall.

[ application example 2]

In the substrate for a display device of the above application example, it is preferable that a protective film for protecting the insulating layer is provided on a surface of the insulating layer.

According to the present application example, a protective film for protecting the insulating layer is provided on the surface of the insulating layer. Therefore, since the insulating layer does not contact the chemical liquid constituting the display device, the chemical liquid and the insulating layer can be prevented from being damaged.

[ application example 3]

In the substrate for a display device of the above application example, preferably, the protective film has an opening, and the partition is provided so as to close the opening.

According to the present application example, the partition wall is provided so as to close the opening of the protective film, whereby the protective film can prevent the chemical liquid constituting the display device from coming into contact with the insulating layer, and the partition wall of the resin can be fixed in contact with the insulating layer of the resin.

[ application example 4]

In the substrate for a display device according to the above-described application example, the substrate preferably includes one pixel electrode corresponding to one pixel, and the partition wall is provided so as to surround the pixel electrode.

According to the present application example, one pixel electrode is provided for each pixel on the substrate. Then, the partition walls are disposed to surround the pixel electrodes. In this case, the area surrounded by the partition wall is smaller than that when the partition wall surrounds the plurality of pixel electrodes. Therefore, since the area inside the partition wall is small, the strength of the partition wall can be improved. As a result, the partition wall can be prevented from toppling or crushing even if a load is applied to the partition wall.

[ application example 5]

In the substrate for a display device according to the above-described application example, it is preferable that a circuit portion electrically connected to the pixel electrode is provided between the substrate and the insulating layer.

According to the present application example, the circuit portion electrically connected to the pixel electrode is provided between the substrate and the insulating layer. Therefore, the circuit portion can be prevented from being eroded by a chemical solution or the like constituting the display device.

[ application example 6]

In the display device substrate according to the above-described application example, the insulating layer is preferably a planarization layer.

According to the present application example, the insulating layer is a planarizing layer, whereby the pixel electrode can be formed in a flat shape, and display quality can be improved.

[ application example 7]

The present application example relates to a display device, including: the substrate for a display device described above; a transparent sealing member supported by the partition wall; a counter electrode provided on the transparent sealing member; a circuit section connected to the pixel electrode between the substrate and the insulating layer; and an electrophoretic dispersion liquid sealed by a space formed by the partition wall, the transparent sealing member, and the substrate.

According to this application example, the display device includes a substrate for display device, and the transparent sealing member is supported by the partition wall. Then, a counter electrode is provided on the transparent sealing member. Partition walls are provided on a substrate for a display device, and an electrophoretic dispersion liquid is provided in a pixel region surrounded by the partition walls. Therefore, the partition wall is located between the display device substrate and the counter electrode. Since the partition wall is less likely to fall or be crushed even if a load is applied to the partition wall, the substrate for a display device, the transparent sealing member, and the counter electrode can be easily assembled.

[ application example 8]

This application example relates to an electronic device, which is characterized by comprising: the display device described above; and a control unit for controlling the display device.

According to the present application example, in the electronic apparatus, the control unit controls the display device. Further, even if the display device applies a load to the partition wall, the partition wall is hard to fall or break, and thus the display device substrate and the transparent sealing member can be easily assembled. Therefore, the electronic apparatus can be a device including a display device in which the display device substrate and the transparent sealing member are easily assembled.

[ application example 9]

The present application relates to a method for manufacturing a substrate for a display device, wherein an insulating layer of a resin material is provided on a substrate, a protective film is provided on the insulating layer, a part of the protective film is removed, and a partition wall of a resin material is provided at a position where the part of the protective film is removed so as to cover the insulating layer.

According to the present application example, an insulating layer of a resin material is provided on a substrate. Then, a protective film is provided on the insulating layer, and a part of the protective film is removed. Thus, a part of the insulating layer is exposed. A partition wall of a resin material is provided so as to cover the exposed insulating layer. Therefore, since the insulating layer of the resin material and the partition wall of the resin material are connected, the insulating layer and the partition wall can be firmly connected. As a result, even if a load is applied to the partition wall in the subsequent process, the partition wall can be prevented from falling or being crushed.

Drawings

Fig. 1 is a schematic perspective view showing the structure of an electrophoretic display device according to a first embodiment.

Fig. 2 is a schematic plan view showing the structure of the electrophoretic display device.

Fig. 3 is a partially schematic exploded perspective view showing the structure of the electrophoretic display device.

Fig. 4 is a schematic side sectional view showing the structure of the electrophoretic display device.

Fig. 5 is a schematic plan view of a main portion for explaining a relationship between pixels and partition walls.

Fig. 6 is an electrical control block diagram of the electrophoretic display device.

Fig. 7 is a schematic side sectional view showing the structure of the electrophoretic display device.

Fig. 8 is a schematic side sectional view showing the structure of the electrophoretic display device.

Fig. 9 is a flowchart of a method of manufacturing an electrophoretic display device.

Fig. 10 is a schematic diagram for explaining a method of manufacturing an electrophoretic display device.

Fig. 11 is a schematic diagram for explaining a method of manufacturing an electrophoretic display device.

Fig. 12 is a schematic diagram for explaining a method of manufacturing an electrophoretic display device.

Fig. 13 is a schematic diagram for explaining a method of manufacturing an electrophoretic display device.

Fig. 14 is a schematic diagram for explaining a method of manufacturing an electrophoretic display device.

Fig. 15 is a schematic diagram for explaining a method of manufacturing an electrophoretic display device.

Fig. 16 is a schematic diagram for explaining a method of manufacturing an electrophoretic display device.

Fig. 17 is a schematic diagram for explaining a method of manufacturing an electrophoretic display device.

Fig. 18 is a schematic diagram for explaining a method of manufacturing an electrophoretic display device.

Fig. 19 is a schematic side sectional view showing the structure of an electrophoretic display device according to the second embodiment.

Fig. 20 is a schematic perspective view showing a structure of an electronic book according to the third embodiment.

Fig. 21 is a schematic perspective view showing the structure of the wristwatch.

Description of the reference numerals

1. An electrophoretic display device as a display device; 2. a first substrate as a substrate for a display device; 5. a partition wall; 6. a pixel region; 7. a first semiconductor element as a circuit portion; 10. a first base material as a substrate; 12. an insulating layer; 13. a protective film; 14. a pixel electrode; 15. electrophoretic dispersion liquid; 22. a common electrode as a counter electrode; 23. a sealing layer as a transparent sealing member; 26. 44, 53, a control unit; 38. an electronic book as an electronic device; 43. a display unit 52 serving as a display device; 45. 54, a signal driving part as a driving device; 48. as a wristwatch for electronic equipment.

Detailed Description

In this embodiment, an electrophoretic display device and a characteristic example of manufacturing the electrophoretic display device will be described with reference to the drawings. Since each member in each drawing is a size that can be recognized in each drawing, each member is illustrated in a different scale.

(first embodiment)

An electrophoretic display device according to a first embodiment will be described with reference to fig. 1 to 18. Fig. 1 is a schematic perspective view showing a structure of an electrophoretic display device, and fig. 2 is a schematic plan view showing the structure of the electrophoretic display device.

As shown in fig. 1, an electrophoretic display device 1 as a display device has a structure in which a first substrate 2 and a second substrate 3 as substrates for the display device are stacked. The thickness direction of the first substrate 2 and the second substrate 3 is defined as the Z direction, and the directions along the side surfaces of the first substrate 2 are defined as the X direction and the Y direction. The second substrate 3 is located on the + Z direction side. When the viewer views the electrophoretic display device 1, the viewer views the electrophoretic display device from the + Z direction side. The surface of the second substrate 3 on the + Z direction side is an image display surface 3 a. The first substrate 2 is longer in the-Y direction than the second substrate 3. On the-Y direction side of the first substrate 2, a flexible cable 4 is provided on the + Z direction side surface. The flexible cable 4 is connected to a drive circuit, not shown, and is supplied with power and drive signals via the flexible cable 4.

As shown in fig. 2, the electrophoretic display device 1 is provided with a partition wall 5 between the first substrate 2 and the second substrate 3. The partition walls 5 have a lattice-like shape and divide the pixel region 6. The dimension of the partition walls 5 is not particularly limited, but in the present embodiment, for example, the width is 3 to 5 μm and the height is 30 μm.

In the figure, 15 pixel regions 6 are arranged in the X direction and 10 pixel regions are arranged in the Y direction for easy viewing of the figure. The number of pixel regions 6 is not particularly limited, but in the present embodiment, for example, 320 pixel regions are arranged in the X direction and 250 pixel regions are arranged in the Y direction. The size of the pixel region 6 is not particularly limited, but in the present embodiment, for example, the length in the X direction is 50 to 100 μm, and the length in the Y direction is 50 to 100 μm. The size of the electrophoretic display device 1 is not particularly limited, but in the present embodiment, for example, the length of the first substrate 2 in the X direction is 30 to 50mm, and the length in the Y direction is 20 to 40 mm.

On the first substrate 2, a first semiconductor element 7 as a circuit portion is provided in each pixel region 6. The first semiconductor element 7 is a switching element that switches a voltage applied to the pixel region 6. Since the first semiconductor elements 7 are located in the respective pixel regions 6, the number of the first semiconductor elements 7 is the same as the number of the pixel regions 6. Then, when a predetermined pattern is displayed on the image display surface 3a, one pixel region 6 becomes one pixel 8. On the + Z direction side surface of the first substrate 2, a signal distributing portion 9 is provided between the second substrate 3 and the flexible cable 4. The signal distributing section 9 switches the signal output to the first semiconductor element 7.

Fig. 3 is a partially schematic exploded perspective view showing the structure of the electrophoretic display device, and is a view in which a part of the electrophoretic display device 1 is exploded in the Z direction. As shown in fig. 3, the first substrate 2 has a first base material 10. As a material of the first substrate 10, glass, plastic, ceramic, silicon, or the like can be used. The first base material 10 may be an opaque material because it is disposed on the opposite side of the image display surface 3a as viewed from the + Z direction.

An element layer 11 is provided on the first substrate 10. The element layer 11 is provided with a voltage supply line 7a, a control signal line 7b, a first semiconductor element 7, a first through electrode 7d, and the like. The first semiconductor element 7 is a tft (thin Film transistor) element, and is an element that performs switching. An insulating layer 12 is provided on the element layer 11, and a protective film 13 and a pixel electrode 14 are sequentially provided on the insulating layer 12. The insulating layer 12 is a layer for insulating the element layer 11 from the pixel electrode 14. The protective film 13 is a layer for protecting the insulating layer 12. The first through electrode 7d of the element layer 11 is connected to the pixel electrode 14. The pixel electrodes 14 are separated in units of the pixel regions 6. The first substrate 2 is constituted by the partition wall 5, the first base 10, the element layer 11, the insulating layer 12, the protective film 13, the pixel electrode 14, and the like.

The material of the element layer 11 is not particularly limited as long as it can form a semiconductor, and silicon, germanium, gallium arsenide phosphide, silicon nitride, silicon carbide, or the like can be used. The material of the insulating layer 12 is not particularly limited as long as it has insulation properties and is easily molded, and a resin material can be used. In the present embodiment, for example, a positive photosensitive acrylic resin is used as a material of the insulating layer 12. The opening portion for exposing a part of the insulating layer 12 can be easily formed by using a positive type. The insulating layer 12 functions as a planarizing layer that does not reflect the irregularities of the element layer 11 in the pixel region 6.

The material of the pixel electrode 14 is not particularly limited as long as it is a material having conductivity, and a material in which a nickel film and a gold film are laminated on a copper foil, and a material in which a nickel film and a gold film are laminated on an aluminum foil can be used in addition to copper, aluminum, nickel, gold, silver, and ITO (indium tin oxide). In the present embodiment, for example, ITO is used as a material of the pixel electrode 14.

Partition walls 5 are provided on the protective film 13 and the insulating layer 12, and an electrophoretic dispersion liquid 15 is filled in the pixel region 6 partitioned by the partition walls 5. The material of the partition 5 is not particularly limited as long as it has appropriate strength, is easy to form, and does not elute into the electrophoretic dispersion liquid 15. A material obtained by adding a crosslinking agent to a resin material such as a polyester resin, a polyolefin resin, an acrylic resin, or an epoxy resin can be used. In the present embodiment, for example, a negative photosensitive epoxy resin is used as a material of the partition wall 5. The convex shape can be easily formed by using a negative type. The partition wall 5 is provided to close the opening of the protective film 13. As can be seen from fig. 3, the width of the opening of the protective film 13 is narrower than the width of the bottom of the partition wall 5. This results in a portion where the partition wall 5 and the insulating layer 12 are not joined to each other through the protective film 13, and the joining can be made firm. The partition wall 5 and the insulating layer 12 are bonded to each other with the protective film 13 interposed therebetween on both sides of the opening, and the insulating layer 12 can be prevented from being damaged by the electrophoretic dispersion liquid 15 from the opening.

The material of the protective film 13 is not particularly limited as long as it has insulation properties and does not elute into the electrophoretic dispersion liquid 15. In this embodiment, for example, silicon nitride is used as a material of the protective film 13. The protective film 13 prevents the insulating layer 12 from being eluted into the electrophoretic dispersion liquid 15. Thereby, the electrophoretic dispersion liquid 15 is prevented from being deteriorated, and the insulating layer 12 is prevented from being deteriorated.

The electrophoretic dispersion liquid 15 has white charged particles 16 as charged particles and black charged particles 17 as charged particles, and the white charged particles 16 and the black charged particles 17 are dispersed in a dispersion medium 18. The material of the white charged particles 16 is not particularly limited as long as it is white, can be charged, and can be formed into fine particles. As the material of the white charged particles 16, for example, particles, polymers, and colloids made of white pigments such as titanium dioxide, zinc white, and antimony trioxide can be used. In the present embodiment, for example, titanium dioxide particles are used as the white charged particles 16 with a positive charge.

The black charged particles 17 are not particularly limited as long as they are black, can be charged, and can be formed into fine particles. As the material of the black charged particles 17, for example, particles, polymers, and colloids made of black pigments such as aniline black, carbon black, and titanium oxynitride can be used. In the present embodiment, for example, titanium oxynitride is used as the black charged particles 17 to charge the negative. As the white charged particles 16 and the black charged particles 17, charge control agents such as electrolytes, surfactants, metal soaps, resins, rubbers, oils, varnishes, and composites can be used as necessary. In addition, a dispersant such as a titanium-based coupling agent, an aluminum-based coupling agent, or a silane-based coupling agent, a lubricant, a stabilizer, or the like may be added to the white charged particles 16 and the black charged particles 17.

The dispersion medium 18 is not particularly limited as long as it is a material that has fluidity and is less likely to change its quality. As the material of the dispersion medium 18, water, an alcohol solvent such as methanol, ethanol, isopropanol, butanol, octanol, or methyl cellosolve, an ester such as ethyl acetate or butyl acetate, a ketone such as acetone, methyl ethyl ketone, or methyl isobutyl ketone, an aliphatic hydrocarbon such as pentane, hexane, or octane, or an alicyclic hydrocarbon such as cyclohexane or methylcyclohexane can be used. In addition, aromatic hydrocarbons such as benzene, toluene, xylene, and benzenes having a long-chain alkyl group can be used as the material of the dispersion medium 18. As the benzene having a long chain alkyl group, hexyl benzene, heptyl benzene, octyl benzene, nonyl benzene, decyl benzene, undecyl benzene, dodecyl benzene, tridecyl benzene, tetradecyl benzene, and the like can be used. In addition, as the dispersion medium 18, a halogenated hydrocarbon such as dichloromethane, chloroform, carbon tetrachloride, 1, 2-dichloroethane, or the like can be used. In addition, oils and silicone oils can be used as the material of the dispersion medium 18. These can be used alone or as a mixture, and a surfactant such as a carboxylate may be blended.

The second substrate 3 is provided on the partition wall 5 and the electrophoretic dispersion liquid 15. The second substrate 3 has a second base material 21. A common electrode 22 as a counter electrode is provided on the second substrate 21, and a sealing layer 23 as a transparent sealing member for sealing the electrophoretic dispersion liquid 15 is provided on the common electrode 22. The common electrode 22 is a common electrode provided over the plurality of pixel regions 6. Therefore, the common electrode 22 faces the plurality of pixel electrodes 14. The sealing layer 23 side of the second substrate 3 is bonded to the partition walls 5. The sealing layer 23 has a function of insulating the partition wall 5 and the common electrode 22.

The material of the second substrate 21 is not particularly limited as long as it has light transmittance, strength, and insulation properties. As the material of the second base 21, glass or a resin material can be used. In the present embodiment, for example, a glass plate is used as the material of the second base material 21.

The common electrode 22 is not particularly limited as long as it is a transparent conductive film. For example, MgAg, IGO (Indium-gallium oxide), ito (Indium Tin oxide), ICO (Indium-cerium oxide), IZO (Indium-zinc oxide), or the like can be used as the common electrode 22. In the present embodiment, for example, ITO is used as the common electrode 22.

The material of the sealing layer 23 is not particularly limited as long as it can be bonded to the partition wall 5, and has light transmittance and insulation properties without causing deterioration of the electrophoretic dispersion liquid 15. For example, as a material of the sealing layer 23, an acrylic resin such as polyurethane, polyurea-polyurethane, urea-formaldehyde, melamine-formaldehyde resin, polyamide, polyester, polysulfonamide, polycarbonate, polysulfonate, epoxy resin, polyacrylate, or the like, polymethacrylate, polyvinyl acetate, gelatin, phenol resin, vinyl resin, or the like can be used. In the present embodiment, for example, an ultraviolet curable acrylic resin or epoxy resin is used.

Fig. 4 is a schematic side sectional view showing the structure of the electrophoretic display device. As shown in fig. 4, the electrophoretic display device 1 is used by applying a voltage between the pixel electrode 14 and the common electrode 22. Then, a voltage is switched between the pixel electrode 14 and the common electrode 22.

The common electrode 22 is set to a low voltage with respect to the pixel electrode 14. At this time, the charged black particles 17 have a negative voltage, and thus the charged black particles 17 are induced to the pixel electrode 14. The white charged particles 16 are charged with a positive voltage, and thus the white charged particles 16 are induced to the common electrode 22. As a result, the black charged particles 17 are collected on the first substrate 2, and the white charged particles 16 are collected on the second substrate 3. When the electrophoretic display device 1 is viewed from the second substrate 3 side, the white charged particles 16 can be seen through the second substrate 3. Therefore, white display is performed in the pixel region 6.

The first semiconductor element 7 is provided in the element layer 11. The first semiconductor element 7 includes a semiconductor film 7e, and a source region 7h, a channel formation region 7k, and a drain region 7j are formed in the semiconductor film 7e in this order. A gate insulating film 7f is provided on the semiconductor film 7e, and a gate electrode 7g is provided on the gate insulating film 7 f. The source region 7h is connected to a source electrode 7n, and the source electrode 7n is connected to a voltage supply line 7 a. A first drain electrode 7p is provided in contact with the drain region 7j, and a first through electrode 7d is provided in contact with the first drain electrode 7 p. Since the first through electrode 7d is connected to the pixel electrode 14, the first semiconductor element 7 is electrically connected to the pixel electrode 14. The gate electrode 7g is connected to the control signal line 7 b.

The main material of the partition wall 5 is an epoxy resin, and the main material of the insulating layer 12 is an acrylic resin. Further, the insulating layer 12 is joined to a part of the partition wall 5. Therefore, the insulating layer 12 and the partition wall 5 are bonded to each other with the same resin material, and the insulating layer 12 and the partition wall 5 can be fixed with higher strength than when one of the insulating layer 12 and the partition wall 5 is an inorganic material. The hardness of the partition wall 5 is 2GPa and the hardness of the insulating layer 12 is 0.5 GPa. The partition wall 5 has higher hardness than the insulating layer 12 and thus has strength. Therefore, even when a load is applied to the partition wall 5 in the step of assembling the first substrate 2 and the second substrate 3, the partition wall 5 is prevented from being deformed or the like and is formed into a shape of being bitten into the insulating layer 12 side, and therefore the partition wall 5 is not easily peeled off from the insulating layer 12. As a result, the partition wall 5 can be prevented from toppling or crushing.

The hardness of the insulating layer 12 before curing was about 15mPa/s, and the hardness of the partition wall 5 before curing was about 2000 mPa/s. Therefore, the material of the insulating layer 12 can be easily formed to be thinner than the material of the partition wall 5. However, since the insulating layer 12 is more easily eluted into the electrophoretic dispersion liquid 15 than the partition wall 5, the protective film 13 is provided to cover the insulating layer 12. Since the insulating layer 12 is not in contact with the electrophoretic dispersion liquid 15 by the protective film 13, the electrophoretic dispersion liquid 15 and the insulating layer 12 can be prevented from being damaged.

A portion of the protective film 13 is located between the partition wall 5 and the insulating layer 12. Specifically, the width of the partition wall 5 on the insulating layer 12 side is set to the first width 5 a. Then, the partition wall 5 is joined to the insulating layer 12 at the center of the partition wall 5 in the width direction of the partition wall 5. The width of the partition wall 5 joined to the insulating layer 12 is set to the second width 5 b. For example, the second width 5b is 1/3 the length of the first width 5 a. Then, the protective film 13 enters between the partition wall 5 and the insulating layer 12 from both side surfaces of the partition wall 5. The length of the portion of the protective film 13 that enters between the partition wall 5 and the insulating layer 12 from the side surface of the partition wall 5 is set to the third width 5 c. For example, the third width 5c is 1/3 of the first width 5 a. At this time, the protective film 13 is present on the insulating layer 12, and a part of the partition wall 5 is present on the protective film 13. Therefore, since the insulating layer 12 is covered with the partition wall 5 and the protective film 13, the insulating layer 12 is not exposed on the surface in contact with the electrophoretic dispersion liquid 15. As a result, the insulating layer 12 can be prevented from contacting the electrophoretic dispersion liquid 15.

Fig. 5 is a schematic plan view of a main part for explaining a relationship between pixels and partition walls, and is a view of the first substrate 2 viewed from the image display surface 3a side. As shown in fig. 5, the first substrate 2 includes one pixel electrode 14 corresponding to one pixel 8. Then, the partition wall 5 is disposed to surround the pixel electrode 14 with respect to one pixel 8. The partition walls 5 may be partially broken instead of surrounding the entire circumference of the pixel electrode 14. Then, the electrophoretic dispersion liquid 15 may be moved between the pixels 8 at the defective position. The partition walls 5 are disposed to surround the pixel electrodes 14. In this case, the area surrounded by the partition wall 5 can be reduced as compared with the case where the partition wall 5 surrounds the plurality of pixel electrodes 14. Then, the strength of the partition wall 5 can be improved. Therefore, even if a load is applied to the partition wall 5, the partition wall 5 can be suppressed from toppling or crushing.

Fig. 6 is an electrical control block diagram of the electrophoretic display device. As shown in fig. 6, the electrophoretic display device 1 is connected to a control device 24 for use. The control device 24 includes an input unit 25, and the input unit 25 is connected to a device that outputs an image signal representing an image displayed on the electrophoretic display device 1, and inputs the image signal. The input unit 25 is connected to the control unit 26. The control unit 26 is connected to the storage unit 27, the first waveform forming unit 28, the second waveform forming unit 29, and the signal distribution unit 9.

The control unit 26 controls the first waveform forming unit 28, the second waveform forming unit 29, and the signal distributing unit 9. The storage unit 27 stores information used when forming a signal to be output to the electrophoretic display device 1 from the image signal, in addition to the image signal. The first waveform forming unit 28 is connected to the first semiconductor element 7 via the flexible cable 4, the signal distributing unit 9, and the control signal line 7b, and outputs a data signal in units of pixels to the first semiconductor element 7. The first semiconductor element 7 is connected to the pixel electrode 14, and outputs a voltage corresponding to a data signal to the pixel electrode 14. The second waveform forming unit 29 is connected to the common electrode 22 via the flexible cable 4 and the signal distributing unit 9, and outputs a voltage waveform to the common electrode 22.

The signal distributing section 9 distributes a drive signal to the first semiconductor element 7 and switches a voltage waveform output to the pixel electrode 14. The signal distributing section 9 transmits the voltage waveform output to the common electrode 22.

Fig. 7 and 8 are schematic side sectional views showing the structure of the electrophoretic display device. As shown in fig. 7, the common electrode 22 is set to a low voltage with respect to the pixel electrode 14. At this time, the charged black particles 17 have a negative voltage, and thus the charged black particles 17 are induced to the pixel electrode 14. The white charged particles 16 are charged with a positive voltage, and thus the white charged particles 16 are induced to the common electrode 22. As a result, the black charged particles 17 are collected on the first substrate 2, and the white charged particles 16 are collected on the second substrate 3. When the electrophoretic display device 1 is viewed from the second substrate 3 side, the white charged particles 16 can be seen through the second substrate 3. Therefore, white display is performed in the pixel region 6.

As shown in fig. 8, the common electrode 22 is set to a high voltage with respect to the pixel electrode 14. At this time, the black charged particles 17 are charged with a negative voltage, and thus the black charged particles 17 are induced to the common electrode 22. Since the white charged particles 16 are charged with a positive voltage, the white charged particles 16 are induced to the pixel electrode 14. As a result, the white charged particles 16 are collected on the first substrate 2, and the black charged particles 17 are collected on the second substrate 3. When the electrophoretic display device 1 is viewed from the second substrate 3 side, the black charged particles 17 can be seen through the second substrate 3. Therefore, black display is performed in the pixel region 6.

Next, a method for manufacturing the electrophoretic display device 1 will be described with reference to fig. 9 to 18. Fig. 9 is a flowchart of a method of manufacturing an electrophoretic display device, and fig. 10 to 18 are schematic diagrams for explaining the method of manufacturing the electrophoretic display device. In the flowchart of fig. 9, step S1 corresponds to the upper electrode setting step. This step is a step of providing the common electrode 22 and the sealing layer 23 on the second substrate 21.

Next, the process proceeds to step S2. Step S2 is a component setting process. This step is a step of providing the element layer 11 on the first substrate 10.

Next, the process proceeds to step S3. Step S3 is an insulating layer setting process. This step is a step of providing the insulating layer 12 on the element layer 11.

Next, the process proceeds to step S4. Step S4 is a protective film setting process. This step is a step of providing the protective film 13 on the insulating layer 12.

Next, the process proceeds to step S5. Step S5 is a lower electrode setting process. This step is a step of providing the first through electrode 7d and the pixel electrode 14 on the protective film 13.

Next, the process proceeds to step S6. Step S6 is a partition wall setting process. This step is a step of providing the partition walls 5 on the first substrate 2.

Next, the process proceeds to step S7. Step S7 is a dispersion filling step. This step is a step of filling the electrophoretic dispersion liquid 15 in the pixel region 6.

Next, the process proceeds to step S8. Step S8 is a substrate assembling process. This step is a step of bonding the partition walls 5 and the second substrate 3.

Through the above steps, the step of manufacturing the electrophoretic display device 1 is completed.

Next, the manufacturing method will be described in detail corresponding to the steps shown in fig. 9 with reference to fig. 10 to 18.

First, the second substrate 3 is manufactured. Fig. 10 corresponds to the upper electrode setting step of step S1. As shown in fig. 10, a second substrate 21 is prepared. A plate in which the surface roughness is reduced by grinding and polishing a glass plate to a predetermined thickness is used as the second base material 21. Next, the common electrode 22 is provided on the second base material 21. An ITO film having a thickness of about 100nm is formed on the second substrate 21 by a film forming method such as a sputtering method. Next, the ITO film is patterned by photolithography and etching to form the common electrode 22.

Next, the sealing layer 23 is provided on the common electrode 22. The sealing layer 23 can be provided by various printing methods such as an ink jet method, relief printing such as offset printing, screen printing, and flexographic printing, and intaglio printing such as intaglio (printing). In addition, spin coating, roll coating, die coating, slit coating, curtain coating, spray coating, cross coating, dip coating, and the like may be used.

Next, the first substrate 2 is manufactured. Fig. 11 is a diagram corresponding to the element disposing step of step S2. As shown in fig. 11, the first base material 10 is prepared in step S2. The first substrate 10 also uses a plate in which the surface roughness is reduced by grinding and lapping a glass plate to a predetermined thickness. An element layer 11 is formed on the first substrate 10. Since the method of forming the element layer 11 is well known, a detailed description thereof will be omitted, and a general manufacturing method will be described. There are a variety of methods for forming the element layer 11, and there are no particular limitations thereon.

First, SiO (not shown) is formed on the first base material 10 by a CVD (chemical vapor deposition) method₂The base insulating film 30. Next, an amorphous silicon film having a thickness of about 50nm is formed on the base insulating film by a CVD method or the like. This amorphous silicon film is crystallized by a laser crystallization method or the like to form a polycrystalline silicon film. After that, a semiconductor film 7e which is an island-shaped polysilicon film is formed by photolithography, etching, or the like.

Next, SiO with a film thickness of about 100nm is formed by a CVD method or the like so as to cover the semiconductor film 7e and the base insulating film₂A gate insulating film 7f is provided. A Mo film having a thickness of about 500nm is formed on the gate insulating film 7f by a sputtering method or the like, and an island-shaped gate electrode 7g is formed by a photolithography method and an etching method.Impurity ions are implanted into the semiconductor film by ion implantation to form a source region 7h, a drain region 7j, and a channel formation region 7 k. SiO with a film thickness of about 800nm is formed to cover the gate insulating film 7f and the gate electrode 7g₂The film is a first interlayer insulating film 11 m.

Next, a contact hole reaching the source region 7h and a contact hole reaching the drain region 7j are formed in the first interlayer insulating film 11 m. Then, a Mo film having a film thickness of about 500nm is formed on the first interlayer insulating film 11m and in the contact hole and the contact hole by a sputtering method or the like, and patterned by a photolithography method and an etching method to form the source electrode 7n, the first drain electrode 7p, and a wiring not shown.

Si having a thickness of about 800nm is formed so as to cover the first interlayer insulating film 11m, the source electrode 7n, the first drain electrode 7p, and the wiring₃N₄The film is a second interlayer insulating film 11 r. Patterning is performed by photolithography and etching, and a contact hole is formed in the second interlayer insulating film 11 r.

Fig. 12 corresponds to the insulating layer providing step of step S3. As shown in fig. 12, in step S3, an insulating layer 12 is provided on the second interlayer insulating film 11 r. First, a resin film to be a material of the insulating layer 12 is provided. On the element layer 11, a solution in which an acrylic resin is dissolved is applied to the element layer 11 and dried to be cured. The resin film can be provided by various printing methods such as ink jet printing, relief printing such as offset printing, screen printing, and flexographic printing, and intaglio printing such as intaglio (printing). In addition, spin coating, roll coating, die coating, slit coating, curtain coating, spray coating, cross coating, dip coating, and the like may be used. Next, the resin film is patterned by photolithography and etching. In this way, the outline shape of the insulating layer 12 and the shape of the through hole 12a are patterned. Next, the insulating layer 12 is etched using an etching solution to form a through hole 12 a.

Fig. 13 and 14 correspond to the protective film providing step of step S4. As shown in fig. 13, in step S4, a SiN film having a thickness of about 500nm is formed on the insulating layer 12 and in the through-hole 12a by a film formation method such as vapor deposition or CVD. Next, as shown in fig. 14, the SiN film is patterned and etched to form a protective film 13. The first drain electrode 7p is exposed in the through hole 12 a. The insulating layer 12 is exposed at the position where the partition wall 5 is provided. The etching method is not particularly limited, but a dry etching method is used in the present embodiment.

Fig. 15 corresponds to the lower electrode setting step of step S5. As shown in fig. 15, in step S5, an ITO film having a thickness of about 500nm is formed on the insulating layer 12, the protective film 13, and the through-hole 12a by a film formation method such as sputtering. Then, the ITO film is etched by photolithography and etching to form the pixel electrode 14 and the first through electrode 7 d. The insulating layer 12 and the protective film 13 are exposed at predetermined positions where the partition walls 5 are provided. The etching method is not particularly limited, but a dry etching method is used in the present embodiment.

Fig. 16 is a diagram corresponding to the partition wall setting process of step S6. As shown in fig. 16, in step S6, the partition walls 5 are provided on the exposed insulating layer 12 and the protective film 13. First, a photosensitive resin material to be a material of the partition wall 5 is applied on the pixel electrode 14. As the coating method, various printing methods such as offset printing, screen printing, and relief printing can be used. In addition, a coating method such as a spin coating method or a roll coating method may be used. Subsequently, the photosensitive resin material is heated and dried to be cured. Next, the photosensitive resin material is patterned by photolithography and etched to form the partition walls 5. The partition walls 5 made of a resin material are provided by covering the insulating layer 12 at positions where a part of the protective film 13 is removed. The first substrate 2 is completed by this process.

Fig. 17 corresponds to the dispersion filling step of step S7. As shown in fig. 17, in step S7, the first substrate 2 provided with the partition wall 5 is set in a container not shown. Then, the white charged particles 16 and the black charged particles 17 are added to the dispersion medium 18 and stirred to prepare an electrophoretic dispersion liquid 15. Next, the electrophoretic dispersion liquid 15 is supplied to the pixel region 6 using a supply instrument such as a syringe. Various printing methods and inkjet methods may be used for supplying the electrophoretic dispersion liquid 15. The electrophoretic dispersion liquid 15 is supplied to the extent of overflowing from the pixel region 6.

Fig. 18 corresponds to the substrate assembly process of step S8. As shown in fig. 18, in step S8, the second substrate 3 is provided on the partition wall 5. First, the first substrate 2 supplied with the electrophoretic dispersion liquid 15 is set in a reduced pressure chamber. Next, the second substrate 3 is mounted on the partition wall 5. Subsequently, the pressure in the decompression chamber is reduced, and the second substrate 3 is pressurized toward the first substrate 2. The sealing layer 23 is irradiated with ultraviolet rays while maintaining this state. The sealant 23 is ultraviolet-curable, and may function as an adhesive to temporarily fix the partition wall 5 and the second substrate 3. Next, the second substrate 3 is fixed to the partition walls 5 by heating the first substrate 2 provided with the second substrate 3 and curing the sealing layer 23. The electrophoretic display device 1 is completed through the above steps.

As described above, according to the present embodiment, the following effects are obtained.

(1) According to the present embodiment, the insulating layer 12 is provided on the first substrate 10. Then, the partition wall 5 is provided on the insulating layer 12. The insulating layer 12 and the partition walls 5 are each formed of a resin material. Therefore, the insulating layer 12 and the partition wall 5 can be fixed with high strength as compared with when one of the insulating layer 12 and the partition wall 5 is an inorganic material and the other is a resin material. Further, the partition wall 5 has higher hardness than the insulating layer 12 and thus higher strength. As a result, even when a load is applied to the partition wall 5, the partition wall 5 can be prevented from peeling off from the insulating layer 12 and falling or crushing.

(2) According to the present embodiment, the protective film 13 for protecting the insulating layer 12 is provided on the surface of the insulating layer 12. Therefore, the electrophoretic dispersion liquid 15 is prevented from contacting the insulating layer 12. Further, the electrophoretic dispersion liquid 15 and the insulating layer 12 can be prevented from being damaged.

(3) According to the present embodiment, a part of the protective film 13 is located between the partition wall 5 and the insulating layer 12. That is, the partition wall 5 is shaped to close the opening of the protective film 13. Therefore, the insulating layer 12 is not exposed in the pixel region 6. As a result, the electrophoretic dispersion liquid 15 can be prevented from contacting the insulating layer 12.

(4) According to the present embodiment, one pixel electrode 14 is provided on the first substrate 2 so as to correspond to one pixel 8. Then, the partition wall 5 is disposed to surround the pixel electrode 14. In this case, the area of the portion surrounded by the partition wall 5 is smaller than that when the partition wall 5 surrounds the plurality of pixel electrodes 14, and therefore the strength of the partition wall 5 can be increased. Thus, the partition wall 5 can be suppressed from toppling or crushing even if a load is applied to the partition wall 5.

(5) According to the present embodiment, the insulating layer 12 and the partition wall 5 are made of a resin material, and the thermal expansion coefficient is close to a value. Therefore, even when the temperature change is large in the manufacturing process of the electrophoretic display device 1, the partition walls 5 can be made less likely to be peeled off from the insulating layer 12.

(6) According to the present embodiment, the insulating layer 12 has a high adhesion force to the partition wall 5. Therefore, even when the electrophoretic dispersion liquid 15 is heated and expanded, the separation of the partition wall 5 from the insulating layer 12 can be suppressed.

(second embodiment)

Next, an embodiment of the electrophoretic display device will be described with reference to fig. 19. Fig. 19 is a schematic side sectional view showing the structure of the electrophoretic display device. The present embodiment is different from the first embodiment in that the protective film 13 is not located between the insulating layer 12 and the partition wall 5. Note that, the description of the same points as those in the first embodiment is omitted.

That is, in the present embodiment, as shown in fig. 19, the electrophoretic display device 33 includes the first substrate 34 and the second substrate 3, and has a structure in which the electrophoretic dispersion liquid 15 is sandwiched between the first substrate 34 and the second substrate 3. In the first substrate 34, the protective film 35 is provided on the insulating layer 12, and is provided on the upper portion of the partition wall 5 and the side surface of the partition wall 5. The protective film 35 on the side surface of the partition wall 5 is not necessarily provided on the entire side surface of the partition wall 5 as long as the insulating layer 12 is not exposed at the boundary between the partition wall 5 and the insulating layer 12. The protective film 35 is not sandwiched by the insulating layer 12 and the partition walls 5. Therefore, the entire bottom surface of the partition wall 5 is connected and fixed to the insulating layer 12. Therefore, the area where the bottom surface of the partition wall 5 contacts the insulating layer 12 is larger than that of the first substrate 2 of the first embodiment, and therefore, the partition wall 5 can be made less likely to be peeled off from the insulating layer 12.

After providing the partition walls 5 to the insulating layer 12, a protective film 35 is formed by a CVD method or the like. After that, the pixel electrode 14 is formed after exposing the first drain electrode 7p in the contact hole. In fig. 19, the protective film 35 is also provided on the upper portion of the partition wall 5, but the protective film 35 on the upper portion of the partition wall 5 may be deleted.

(third embodiment)

Next, an embodiment of an electronic device having an electrophoretic display device mounted thereon will be described with reference to fig. 20 and 21. Fig. 20 is a schematic perspective view showing a structure of an electronic book, and fig. 21 is a schematic perspective view showing a structure of a wristwatch. As shown in fig. 20, an electronic book 38 as an electronic device has a plate-like housing 39. A lid 41 is provided to the housing 39 via a hinge 40. The housing 39 is provided with an operation button 42 and a display unit 43 as a display device. The operator can operate the operation buttons 42 to operate the contents displayed on the display unit 43.

A control unit 44 and a signal driving unit 45 for driving a data signal to the display unit 43 are provided inside the housing 39. The control section 44 outputs the display data to the signal driving section 45, and also outputs a timing signal when the display data is converted into a data signal. The signal driving unit 45 generates a data signal from the display data and outputs the data signal to the display unit 43. The control unit 44 outputs a display control signal synchronized with the data signal output from the signal driving unit 45 to the display unit 43. The display unit 43 generates a signal necessary for electrophoretic display in a signal unit assignment circuit provided in the display unit 43 based on the input display control signal and data signal, and can perform display in accordance with the display data output from the control unit 44 to the display unit 43. The operation of the operator by the operation button 42 is signaled to the control unit 44 at a proper timing, and is reflected in the output signal of the control unit 44. Either one of the electrophoretic display device 1 and the electrophoretic display device 33 is used in the display unit 43. Therefore, the electrophoretic display device having the structure in which the partition walls 5 are difficult to tilt and easy to assemble can be applied to the display unit 43.

As shown in fig. 21, the wristwatch 48 as an electronic device has a plate-like case 49. The case 49 includes a band 50, and the operator can wrap the band 50 around the wrist to fix the wristwatch 48 to the wrist. The casing 49 is provided with an operation button 51 and a display unit 52 as a display device. The operator can operate the operation buttons 51 to operate the contents displayed on the display unit 52.

A control unit 53 for controlling the wristwatch 48 and a signal driving unit 54 for driving a signal to the display unit 52 are provided inside the case 49. The control unit 53 outputs display data and necessary timing signals to the signal driving unit 54. The necessary timing signals may include a signal directly output from the control unit 53 to the display unit 52. The signal driving unit 54 outputs a signal necessary for display to the display unit 52, thereby enabling the display unit 52 to display the content corresponding to the display data. In addition, either the electrophoretic display device 1 or the electrophoretic display device 33 is used in the display unit 52. Therefore, the electrophoretic display device having the structure in which the wristwatch 48 is difficult to tilt and easy to assemble can be applied to the display unit 52.

The present embodiment is not limited to the above-described embodiments, and various changes and modifications can be made by a person having ordinary knowledge in the art within the technical idea of the present invention. The modifications are described below.

(modification 1)

In the first embodiment, the electrophoretic dispersion liquid 15 is provided with white charged particles 16 and black charged particles 17. Instead of the white charged particles 16 and the black charged particles 17, charged particles such as red, green, and blue may be used. With this configuration, color display can be performed by displaying red, green, blue, and the like. In addition, only one color of charged particles may be used in the electrophoretic dispersion liquid 15.

(modification 2)

In the first embodiment, one pixel electrode 14 is provided in one pixel region 6. A plurality of pixel electrodes 14 may be provided in one pixel region 6. The display can be subdivided.

(modification 3)

In the first embodiment, the white charged particles 16 are positively charged, and the black charged particles 17 are negatively charged. The white charged particles 16 may be negatively charged and the black charged particles 17 may be positively charged. The charging state can be easily controlled.

(modification 4)

In the first embodiment, the pixel region 6 has a quadrangular shape. The shape of the pixel region 6 may also be a circle, an ellipse, a polygon, and a shape including a circular arc and a straight line. At this time, the partition wall 5 is formed of a resin material, and thus the shape of the partition wall 5 can be easily matched with the shape of the pixel region 6.

(modification 5)

In the first embodiment, the first substrate 2 and the second substrate 3 are bonded after the electrophoretic dispersion liquid 15 is provided to the pixel region 6 of the first substrate 2. In addition, the electrophoretic dispersion liquid 15 may be provided in the pixel region 6 after the first substrate 2 and the second substrate 3 are bonded to each other with the pixel region 6 in communication with each other. The process sequence can be easily manufactured.

(modification 6)

In the first embodiment, the first semiconductor element 7 is provided on the first substrate 2. The first substrate 2 may be provided with only the pixel electrode 14 without the first semiconductor element 7. Further, a drive circuit for directly applying a voltage to the pixel electrode 14 may be provided. The first substrate 2 has a simple structure and can be easily manufactured.

Japanese patent application 2015-184810 filed on 2015, 9, 18 and 18 to this franchise is incorporated herein in its entirety.

Claims (19)

1. A substrate for a display device, which is brought into contact with an electrophoretic dispersion liquid, comprising in this order:

a substrate including an insulating layer formed of a resin material;

a protective film disposed on a surface of the insulating layer to protect the insulating layer from contact with the electrophoretic dispersion liquid;

a partition wall disposed on the insulating layer, the partition wall being formed of a resin material, the partition wall forming a partitioned space.

2. The substrate for a display device according to claim 1, wherein the insulating layer is formed using a positive photosensitive acrylic resin.

3. The substrate for a display device according to claim 1, wherein the partition walls comprise a polyester resin, a polyolefin resin, an acrylic resin, or an epoxy resin.

4. The substrate for a display device according to claim 1, wherein the partition walls comprise a crosslinked resin.

5. The substrate for display device according to claim 3, wherein the partition wall comprises a negative-type photosensitive epoxy resin.

6. The substrate for a display device according to claim 1, wherein a hardness of the partition walls is higher than a hardness of the insulating layer.

7. The substrate for a display device according to claim 1, wherein the substrate comprises a pixel electrode corresponding to a pixel, and the partition wall is provided so as to surround the pixel electrode.

8. The substrate for a display device according to claim 7, wherein a circuit portion is electrically connected to the pixel electrode, and the insulating layer is provided between the circuit portion and the pixel electrode.

9. The substrate for a display device according to claim 1, wherein the insulating layer is a planarization layer.

10. The substrate for a display device according to claim 1, wherein the protective film has an opening portion, and wherein the partition wall is provided so as to close the opening portion.

11. The substrate for a display device according to claim 10, wherein a width of the opening of the protective film is narrower than a width of a bottom portion of the partition wall.

12. A display device comprising, in order:

the substrate for a display device according to claim 1;

a transparent sealing member supported by the partition wall; and

a counter electrode provided on the transparent sealing member;

wherein the electrophoretic dispersion liquid is sealed in a space formed by the partition wall, the transparent sealing member, and the substrate.

13. An electronic device, comprising:

the display device according to claim 12; and

and a control unit for controlling the display device.

14. A method for manufacturing a display device, comprising the steps of:

providing a first substrate comprising a first base material and an element layer;

an insulating layer of a positive photosensitive acrylic resin material is provided on the element layer;

providing a protective film on a surface of the insulating layer;

removing a portion of the protective film; and

providing a partition wall of a resin material covering the insulating layer at a position from which a portion of the protective film is removed, the partition wall forming a partitioned space;

filling the partitioned space with an electrophoretic dispersion;

providing a second substrate including a second base material, a common electrode, and a transparent sealing member in this order;

bonding the transparent sealing member of the second substrate to the partition wall.

15. The method of claim 14, wherein the partition wall comprises a polyester resin, a polyolefin resin, an acrylic resin, or an epoxy resin.

16. The method of claim 15, wherein the partition walls comprise a negative-type photosensitive epoxy material.

17. The method of claim 16, further comprising the steps of:

the photosensitive resin material of the partition walls is patterned using photolithography.

18. The method of claim 14, further comprising the steps of:

patterning the photosensitive resin material of the insulating layer using photolithography.

19. The method of claim 14, wherein the protective film comprises silicon nitride (SiN).