KR20010087418A - Assembly of microencapsulated electronic display - Google Patents

Abstract

Electro-optical devices are manufactured by separately manufacturing electronic and optical components, and then integrating the electronic and optical components. By making the two components separately, each component can be prepared using a process that optimizes its own properties.

Description

Assembling method of microcapsule electronic display device {ASSEMBLY OF MICROENCAPSULATED ELECTRONIC DISPLAY}

Electronic displays include optical components such as liquid crystals and electrophoretic particles, and electronic components such as electrodes and driving circuits. Optical and electronic components have different performance categories. For example, it is desirable for electronic components to optimize conductivity, voltage-current relationship, capacitance, etc., or to have memory, logic, or other high-level electronic device capabilities, while optical components optimize reflectivity, contrast, and response time. It is preferable. Thus, the process of preparing the optical component may not be ideal for preparing the electronic component, and vice versa. For example, the process of manufacturing the electronic component may include treating at high temperature. The treatment temperature may range from 300 ° C to 600 ° C. However, bringing many optical components to such high temperatures can be detrimental to the optical components as they cause chemical damage or mechanical damage to components (eg, electrophoretic particles or liquid crystals).

Related Applications

This application was filed in the U.S.S.N. Provisional application filed December 15, 1998 in the United States. As claiming priority of 60 / 112,330, the entire disclosure is incorporated herein by reference. This application is a U.S. utility model U.S.S.N. 09 / 338,412 and U.S.S.N. filed April 9, 1999. As part of the continuing application (CIP application) of 09 / 289,036, the entire disclosure is incorporated herein by reference.

Technical Field

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to a method for manufacturing an electronic display device, and more particularly, to a method for assembling an electronic display device.

The foregoing and other objects, features, and advantages of the present invention, as well as the present invention itself, will be fully understood from the following description of the preferred embodiments with reference to the accompanying drawings.

1 is a cross-sectional view of a modulation layer of an electronic display device according to an embodiment of the present invention.

2 is a cross-sectional view of a pixel layer of an electronic display device according to an embodiment of the present invention.

3 is a cross-sectional view of a sub-assembly of the modulation layer of FIG. 1 and the pixel layer of FIG. 2 in accordance with an embodiment of the present invention.

4A illustrates the integration of the sub-assembly and circuit layer of FIG. 3 in accordance with an embodiment of the present invention.

FIG. 4B illustrates the integration of the sub-assembly and circuit layer of FIG. 3 in accordance with another embodiment of the present invention. FIG.

5 is a cross-sectional view of the electronic ink assembly according to an embodiment of the present invention.

FIG. 6A illustrates the integration of the electronic ink assembly and the second circuit layer of FIG. 5 in accordance with an embodiment of the present invention. FIG.

6B is a cross-sectional view of an electronic ink integrated using the method of FIG. 6A.

FIG. 7A illustrates a sub-assembly formed by integrating a pixel layer and a circuit layer according to an embodiment of the present invention. FIG.

FIG. 7B illustrates the integration of a sub-assembly of a pixel layer and a circuit layer into a modulation layer in accordance with an embodiment of the present invention. FIG.

8A is a partial cross-sectional view of an electronic display medium according to an embodiment of the present invention.

8B is a partial cross-sectional view of an electronic display medium according to an embodiment of the present invention.

8C is a partial cross-sectional view of an electronic display medium according to an embodiment of the present invention.

8D is a partial cross-sectional view of an electronic display medium according to an embodiment of the present invention.

9A illustrates a first surface of a pixel layer in accordance with one embodiment of the present invention.

9B illustrates a second surface of a pixel layer in accordance with one embodiment of the present invention.

10 is a partial cross-sectional view of a transistor for addressing an electronic display device according to an embodiment of the present invention.

11 illustrates a connection between a transistor and an electrode of an electronic display device according to an embodiment of the present invention.

Summary of the Invention

One way to solve this problem is to change the time-series arrangement of the display device manufacturing, so that the electronic components requiring high temperature treatment are processed first, and the optical components requiring low temperature treatment are processed second. Another way to solve this problem is to treat the optical and electronic components separately and combine the two components later.

The present invention relates to a method of manufacturing an electro-optical device. According to one embodiment, the electro-optical device is manufactured according to the following procedure. First, a modulation layer, a pixel layer, and a circuit layer are provided. The modulation layer comprises a first substrate and an electro-optical material provided in contact with the first substrate. The modulating layer can change the visible state depending on the application of the electric field. The pixel layer includes a second substrate. A plurality of pixel electrodes are provided on the front side of the second substrate, and a plurality of contact pads are provided on the back side of the second substrate. Each pixel electrode is connected to the contact pad through a via extending through the second substrate. The circuit layer includes a third substrate and at least one circuit element. The modulation layer, pixel layer, and circuit layer are integrated to form the electro-optical device.

In one embodiment, the pixel layer and modulation layer are first integrated to form a sub-assembly, and then the circuit layer and sub-assembly are integrated to form an electro-optical device. For example, the pixel layer and the modulation layer can be integrated through encapsulation. Alternatively, the edge portion of the pixel layer and the edge portion of the modulation layer may be sealed together. Circuit layer and sub-assembly can be integrated by adhering the two layers. For example, the circuit layer and sub-assembly can be bonded by inserting an adhesive layer comprising an anisotropic conductive material between the two layers.

In another embodiment, the pixel layer and the circuit layer are first integrated to form a sub-assembly, and then the modulation layer and sub-assembly are integrated to form an electro-optical device.

In one embodiment, the electro-optical material comprises a plurality of capsules, each capsule comprising a plurality of particles dispersed in a fluid. For example, the plurality of particles can be electrophoretic particles. In another embodiment, the electro-optical material comprises a liquid crystal. In another embodiment, the electro-optical material is a plurality of capsules, each capsule comprising a bichromal sphere dispersed in a fluid.

In one embodiment, the modulating layer comprises a flexible substrate. For example, the modulation layer may be an organic layer.

In one embodiment, the pixel layer includes an insulating substrate. By printing or evaporating the conductive material on the front surface of the substrate, a pixel electrode can be formed to form a pixel layer.

In one embodiment, the circuit layer may include one or more of the following elements; Data line drivers, select line drivers, power supplies, sensors, logic devices, memory devices, and communication devices. For example, the circuit layer may include a nonlinear device such as a transistor. Transistors can be made by printing organic-based field effect transistors on the front side of the circuit layer.

In one embodiment, the modulation layer, pixel layer and circuit layer are tested before integration.

In another embodiment, the invention features an electro-optical device made using the method described above. The electro-optical device may be an electronic display device.

The present invention relates to a method of packing or assembling an electronic display. Referring to FIG. 1, a modulation layer 10 is provided, which is manufactured using the method described to optimize the optical quality of the modulation layer 10. The modulation layer 10 includes a substrate 12 and a display medium 14 provided after the substrate 12. The substrate 12 comprises a front common electrode 16 deposited on the first surface 13 of the substrate 12 after the display medium 14. Display medium 14 comprises microcapsules 18 dispersed in a binder 20. Each microcapsule 18 comprises an electro-optical material. Electro-optical materials refer to materials that display optical properties in response to electrical signals. Examples of electro-optical materials may be liquid crystalline fluids or electrophoretic particles dispersed in a solvent. The electro-optical material may also be a dichroic sphere dispersed in a solvent. Details of the electro-optical material in the microcapsules 18 will be described in more detail with reference to FIGS. 8A-8D. An important property of the electro-optical material in the microcapsules 18 is that it is possible to display one field of view depending on the application of an electric field and to display another field of view according to the application of another field.

Referring to FIG. 2, a pixel layer 22 is provided, prepared using the method to be discussed that optimizes the electrical properties of the pixel layer 22. The pixel layer 22 is provided with a substrate 23, a pixel electrode 24 provided on the first surface 21 of the substrate 23, and a contact pad 26 provided on the second surface 25 of the substrate 23. ) Each pixel electrode 24 is electrically connected to the contact pad 26 through the via 28. In order to maximize the electrical contact probability between the pixel electrode 24 and the contact pads 26, as shown in FIG. 2, one or more vias 28 are provided between each pixel electrode 24 and its corresponding contact pads 26. Can be provided. The pixel layer 22 will be described in detail with reference to FIGS. 9A and 9B.

Separately prepared, the modulation layer 10 of FIG. 1 and the pixel layer 22 of FIG. 2 are integrated as shown in FIG. 3 to form the sub-assembly 30. The pixel electrode 24 is provided with a common electrode 12 after the first surface 13 of the display medium 14 and the pixel electrode 24 after the second surface 11 of the display medium 14. To be provided, it is in contact with the second surface 11 of the modulation layer 10. The pixel layer 22 can be combined into the modulation layer 10 by providing an adhesive material between the pixel layer 22 and the modulation layer 10. The adhesive material has electrical, mechanical and chemical properties compatible with the pixel layer 22 and the modulation layer 10. In order to facilitate the connection between the pixel layer 22 and the modulation layer 10, the sub-assembly 30 uses standard pressurization mechanisms known to those skilled in the art, such as vacuum laminators and thermal presses. Can be pressurized.

The edge portion of the sub-assembly 30 can be sealed using a seal 32, shown in FIG. 3. The edge seal material 32 may be selected from many commercial materials such as one-part or two-part epoxy. In another embodiment, sub-assembly 30 may be encapsulated with a protective material. The capsule material may be selected from a number of commercially transparent materials, such as vapor-deposited parylene. In this embodiment, the contact pads 26 are provided with electrical connections with the circuit layer exposed. Alternatively, it may be encapsulated in a protective material after the final assembly of the electronic display device is provided. Protective materials used in encapsulation protect the electro-optical materials and electronic devices from the environment.

4A and 4B, the sub-assembly 30 is integrated into the circuit layer 40. The circuit layer 40 comprises the substrate 41, the pixel circuit and the pixel electrode contacts 42 provided on the first surface 45 of the substrate 41, and the logic 44 provided on the substrate 41. Include. Details of the circuit layer 40 will be described with reference to FIGS. 10 and 11. In one embodiment, the sub-assembly 30 is bonded with the circuit layer 40 using bonding techniques known to those skilled in the art, such as thermocompression, thermosonic bonding or mechanical bonding. do.

In the embodiment of FIG. 4A, an adhesive layer 46 is provided between the second surface 25 of the pixel layer 22 of the sub-assembly 30 and the first surface 45 of the circuit layer 40. In order to improve adhesion and planarization, the adhesive layer 46 has a second surface 25 of the pixel layer 22 around the contact pad 26 and a first surface of the circuit layer 30 around the pixel electrode contact 42. 45 may be provided. For example, the adhesive layer 46 may be a film coated with an adhesive material on both sides. An example of such an adhesive layer is a double coated film tape Nos. Of 3M (St. Paul, MN, US). 9443, 443 and 444. In one embodiment, an adhesive layer 46 is printed on the second surface 25 of the pixel layer 22 and / or the first surface 45 of the circuit layer 40.

In the embodiment of FIG. 4B, an anisotropic conductive film 47 is provided between the second surface 25 of the pixel layer 22 and the first surface 45 of the circuit layer 40. The anisotropic conductive film 47 is, for example, conductive only on the z-axis, that is, only through one axis. The anisotropic conductive film 47 is a z-axis adhesive film Nos. Like 5303 and 7303, it may comprise silver particles dispersed within the adhesive matrix. The anisotropic conductive film 47 can provide a feed passage between the contact pad 26 and the pixel electrode contact 42.

After providing the adhesive layers 46 and 47 between the pixel layer 22 and the circuit layer 30, the sub-assembly 30 and the circuit layer 40 can be pressed to adhere to each other. As shown in FIG. 5, to assemble the sub-assembly 30 and the circuit layer 40 to form the assembly 50, standard equipment known to those skilled in the art such as a vacuum laminator and a thermopressor can be used. In one embodiment, pixel layer 22 and circuit layer 40 are connected via an edge connection in addition to via 28.

6A and 6B, the circuit layer 40 of the assembly 50 is further connected to the second circuit layer 70. The second circuit layer 70 further includes an electronic device for driving the electronic display device. The second circuit layer 70 may include a high performance integrated circuit 74 and a flexible printed circuit board 72 that perform a control function of the electronic display device. The first circuit layer 40 and the second circuit layer 70 can be connected via a ribbon cable 78. The second circuit layer 70 can be used to address the display medium 14. As an alternative, the second circuit layer 70 can be used to address the second display medium provided after the second circuit layer 70. In this embodiment, the electronic display includes two display surfaces.

The order of assembling the modulation layer 10, the pixel layer 22 and the circuit layer 40 is not limited to the order described with reference to FIGS. 1 to 3, 4A and 4B, and 5. Referring to FIGS. 7A and 7B, the pixel layer 22 is first stacked on the circuit layer 40 to form the sub-assembly 35, and then the modulation layer 10 is stacked to form the sub-assembly 35. Can be formed. The order of assembling the modulation layer 10, the pixel layer 22, and the circuit layer 40 is that the temperature and the compression pressure required for laminating the pixel layer 22 to the circuit layer 40 are controlled by the modulation layer 10. It is desirable outside the scope.

Alignment of the modulation layer 10, pixel layer 22, circuit layer 40 may be enabled by mechanical and / or photograph alignment markers. For example, the alignment marker is at the correct position on the second substrate 25 of the pixel layer 22 and the first surface 45 of the circuit layer 40, preferably on the pixel layer 22 and the circuit layer 40. Printed on the opposite corner, the relative position of the pixel layer 22 and the circuit layer 44 can be adjusted until all the markers are aligned. For plastic or deformable substrates, the alignment form can be embossed on one substrate and punched on another substrate to provide an alignment joint that engages each other.

The method for assembling an electronic display device according to the present invention allows each of the modulation layer, pixel layer, and circuit layer to be processed separately, thereby optimizing its performance characteristics. In addition, each of the modulation layer, pixel layer, and circuit layer can be tested post-assembly prior to assembly. Such capability leads to a reduction in manufacturing costs. In one embodiment, the sub-assembly of the modulation and pixel layers can be tested prior to assembly by simply contacting the sub-assembly with the circuit layer.

In one embodiment, the display medium used to form the electronic display device includes a particle based display medium. In one specific embodiment, the particle-based display medium includes an electronic ink. Electron ink is an optoelectronically active material comprising at least two states, two states of electrophoresis versus a medium and a coating / binding state. Electrophoretic conditions include, in some embodiments, a single type of electrophoretic particles dispersed in a clean or colored medium, or one or more types of electrophoretic particles having distinct physical and electrical properties, dispersed in a clean or colored medium. do. In some embodiments, the electrophoretic state is encapsulated, that is, there is a capsule wall state between the two states. In one embodiment, the coating / binding state comprises a polymer matrix surrounding the electrophoretic state. In this embodiment, the polymer of the polymer binder can be dried, crosslinked, or cured like a traditional ink, so that a printing process can be used to deposit the electron ink on the substrate.

The optical quality of electronic ink has very different properties from other electronic display materials. The most notable difference is that electronic inks provide very high reflectivity and contrast because they are based on coloration (like normal print inks). The light scattered from the electron ink comes from a very thin layer of pigment near the screen tip. For this reason, it is similar to a normal printed image. In addition, electronic inks can be easily viewed with a wide range of field of view, such as printed pages, which approximate a Lambertian contrast curve closer than other electronic display materials. Since electronic inks are printable, they can be included on the same surface with any other print material, including conventional inks. The electronic ink may be optically stable in all display states, that is, may be set to an optical state that is difficult to disassemble. Fabricating a display device by printing an electronic ink is particularly useful for low power applications because of its stability.

Electronic ink display devices are novel because they are addressed with a DC voltage and can draw very little current. That is, the conductive lead and the electrode used to transfer the voltage to the electronic ink display device may have a relatively high resistance. By using a resistive conductor substantially, the number and shape of materials that can be used as a conductor of an electronic ink display device are expanded. In particular, it is not necessary to use expensive vacuum-sputtered ITO conductors, which are standard materials for liquid crystal displays. Aside from cost savings, the replacement of ITO with other materials can provide benefits in appearance, throughput (printed conductors), flexibility and durability. In addition, the printed electrode is in contact only with the solid binder and not with the fluid layer (such as liquid crystal). This means that some conductive materials can be applied to the electronic ink that can be degraded or damaged by contact with the liquid crystal. These include both conductive transparent inks as well as opaque metallic inks (eg silver and graphite inks) of the back electrode. Such conductive coatings include conductive or semiconducting colloids, examples being antimony doped tin oxide and indium tin oxide. Organic conductors (polymer conductors and molecular organic conductors) can also be used. Polymers include polyaniline and its derivatives, polythiophene and its derivatives, poly 3,4-ethylenedioxythiopine (PEDOT) and its derivatives, polypyrrole and its derivatives, and polyphenylene Vinylene (PPV) and derivatives thereof, and the like. Organic molecular conductors include, but are not limited to, derivatives of phthalocyanine, pentacene and naphthalene. The polymer layer may be thinner and transparent than conventional display devices because the conductivity requirements are not stringent.

8A shows an electrophoretic display 130. The binder 132 includes a plurality of particles 136 and at least one capsule 134 filled with colored suspended fluid 138. In one embodiment, the particles 136 are titania particles. When a DC field of appropriate polarity is applied to the capsule 134, the particles 136 move to the visible surface of the display and scatter light. As the applied electric field is reversed, particles 136 move to the back of the display and the visible surface of the display appears dark.

8B shows another electrophoretic display 140. The display device includes a first particle set 142 and a second particle set 144 in the capsule 141. The first particle set 142 and the second particle set 144 have contrasting optical properties. For example, the first particle set 142 and the second particle set 144 may have different electrophoretic mobility. In addition, the first particle set 142 and the second particle set 144 may have contrasting colors. For example, the first particle set 142 may be white while the second particle set 144 may be black. Capsule 141 further includes a substantially clean fluid. The capsule 141 includes an electrode 146 and an electrode 146 ′ disposed in contact with the electrode 146. The electrodes 146, 146 ′ are connected to a voltage source 148, which may provide an alternating or direct current field to the capsule 441. When an electric field is applied between the electrodes 146, 146 ′, the first particle set 142 moves toward the electrode 146 ′, while the second particle set 144 moves toward the electrode 146.

8C shows a suspended particle display 150. Suspended particle display 150 includes acicular particles 152 of transparent fluid 154. Particle 152 changes its orientation in response to the application of an alternating electric field between electrodes 156 and 156 '. When an alternating electric field is applied, particles 152 are oriented perpendicular to the display surface, and the display appears transparent. When the alternating electric field is removed, the particles 152 are randomly oriented, and the display device 150 appears opaque.

The electrophoretic display devices provided in FIGS. 8A to 8C are merely exemplary, and other electrophoretic display devices may be used in accordance with the present invention. Examples of other electrophoretic displays are described in co-owned US patent applications Ser. Nos. 08 / 935,800 and 09 / 140,792, which are incorporated herein by reference.

Successful configurations of encapsulated electrophoretic displays include binders, electrophoretic particles, fluids (e.g., surrounding the electrophoretic particles and providing a medium for migration), and capsule thin films (e.g., electrical Proper interaction between the moving particles and the fluid). All of these components must be chemically compatible. The capsule thin film may introduce useful surface interactions with the electrophoretic particles and may serve as an inert physical boundary between the fluid and the binder. The polymer binder may be set as an adhesive between the capsule thin film and the electrode surface.

Various materials can be used to make the electrophoretic display. The choice of such material is based on the functional components of the display to be manufactured. Such functional components are, but are not limited to, particles, dyes, suspended fluids, stabilization / filling additives, binders, and the like. In one embodiment, the form of particles that can be used to make the suspended particle display includes scattering pigments, absorbing pigments, fluorescent particles. Such particles may be transparent. Examples of particles include titania coated with one or two metal oxide layers, for example aluminum oxide or silicon oxide. Such particles can be composed of corner cubes. The fluorescent particles may comprise zinc sulfide particles, for example. Zinc sulfide particles may be encapsulated with an insulating coating to reduce electrical conductivity. Light shielding or light absorbing particles may comprise, for example, pigments or pigments. Forms of pigments used in electrophoretic displays are known to those skilled in the art. Useful pigments are typically soluble in suspended fluids and may be part of the polymer chain. Pigments can be polymerized by thermal, photochemical and chemical diffusion processes. Single pigments or mixtures of pigments may be used.

Suspended (ie, electrophoretic) fluid may be a high resistivity fluid. The floating fluid can be a single fluid or a mixture of two or more fluids. Whether a single fluid or a mixed fluid, the suspended fluid may have a density that substantially matches the density of the particles in the capsule. Suspended fluids can be halogenated hydrocarbons such as, for example, tetrachloroethylene. Halogenated hydrocarbons may be low molecular weight polymers. One such low molecular weight polymer is poly (chlorotrifluoroethylene). The degree of polimerization of such polymers may be from about 2 to about 10.

In addition, capsules may be formed in the binder and dispersed later. Materials used in the binder include water soluble polymers, water-dispersed polymers, fat soluble polymers, thermosetting polymers, thermoplastic polymers, and UV curable or radiation cured polymers.

While the examples described below are enumerated using encapsulated electrophoretic displays, there are other particle-based display media that can operate well, including encapsulated suspended particles and rotating ball displays. . Other displays such as liquid crystals and magnetic particles may also be useful.

In some cases, no separate encapsulation procedure is needed during the process. The electrophoretic fluid is either dispersed or emulsified directly into a binder (or pre-additive to binder material) to form what is called a "polymer dispersed electrophoretic display". In such displays, the individual electrophoretic states are called capsules or microcapsules even if no capsule thin film is present. Such polymer dispersed electrophoretic displays are considered a subclass of encapsulated electrophoretic displays.

In an encapsulated electrophoretic display, a binder material surrounds the capsule and separates the two bounding electrodes. Such binder material should be compatible with the capsule and the bounding electrode, and should have properties that facilitate printing or coating. It may have barrier properties to water, oxygen, ultraviolet light, electrophoretic fluids, or other materials. In addition, it may include a surfactant and a crosslinking agent for coating aid or durability improvement. The polymer dispersed electrophoretic display may be of emulsion or phase seperation type.

In another detailed embodiment, the display medium may include a plurality of dichroic spheres shown in FIG. 8D. Dichroic spheres 160 typically have a positively charged hemisphere 162 of a first color and a negatively charged hemisphere 164 of a second color in a fluid medium 166. When an electric field is applied between the spheres 160 through the pair of electrodes 168 and 168 ', the spheres 160 rotate and display the color of one of the two hemispheres 162 and 164.

In one embodiment, an electronic display is generated by printing the entire display device or a portion of the display device. The term “print” is intended to include all forms of printing and coatings, including inkjet printing, premetered coatings such as patch die coating, slot or extrusion coating, slide or cascade coating, and curtain coating ; Roll coatings such as knife over roll coating, forward and reverse roll coating; Grabber coatings; Dip coating; Spray coating; Meniscus coatings; Spin coating; Brush coating; Air knife coating; Screen printing process; Electrostatic printing process; Thermal printing process; And other similar techniques.

9A and 9B, the pixel layer 200 is described in more detail. Pixel layer 200 includes a substrate 202 having a first surface 204 and a second surface 206. Substrate 202 can be, for example, polyethylene terephthalate (PET, polyester), polyethersulfone (PES), polyimide film (e.g. Upilex from Dupont (Wilington, DE) and Ube (japan)), or polycarbonate It may be made of an insulating polymer material such as. An advantage of the insulator substrate 202 is that the substrate 202 not only protects the pixel electrode 208 from the environment, but also protects the display medium. An array of pixel electrodes 208 is provided on the first surface 204 of the substrate 202. The pixel electrode 208 is arranged to obtain a high aperture ratio or fill factor. An electrically conductive material may be deposited or printed on the first surface 204 of the substrate 202 to form the pixel electrode 208. The pixel electrode 208 is connected to the second surface 206 of the substrate 202 through the electrical via 210. The electrical via 210 can be formed using one of several techniques. For example, holes may be formed in the pixel array 200 using any of pricking, laser drilling, or etching techniques. Next, the holes are filled by printing low-resistance slurries such as carbon, graphite, or silver particles mixed in the polymer compound. An array of contact pads 212 is provided on the second surface 206 of the pixel array 200. Contact pad 212 can be fabricated using one of many methods known to those skilled in the art. For example, a conductive material may be deposited or printed on the second surface 206 of the substrate 202 to form the contact pad 212.

The pixel layer can also be processed to include a variety of electrical, thermal, and optical layers to improve display performance. For example, a thermoelectric (TE) heater or cooler may be provided on both surfaces of the substrate to allow for space utilization so that the electro-optical material is within its thermal operating range. The thermoelectric heater may be integrated by providing a trace of the resistive material on the surface of the substrate 202. By passing current through this trace, the display temperature can be constant. Conversely, a thermoelectric cooler, such as a Peltier cooler, can be used to transfer thermal energy from the display to the appropriate heat sink.

The pixel layer may comprise grounded thin metal foils and / or reflective or opaque light shields. A grounded thin metal foil or light shield is used to enhance the optical performance of the display device and to optically shield the photosensitive microelectronic elements from light. For example, the pixel layer or circuit layer may comprise a semiconducting material, many of which are known as photosensitivity. Thin foils or light shields may be included on one or more surfaces of the pixel layer or circuit layer such that the photosensitive material is optically shielded from all incident light.

The circuit layer may include electrodes such as row electrodes and column electrodes, nonlinear elements, and driving circuits or logic elements for addressing the display device. For example, the circuit layer may include the transistors shown in FIGS. 10 and 11.

Referring to FIG. 10, the field effect transistor 210 of the organic substrate is formed on the substrate 212, the gate electrode 214 provided on the substrate 212, the dielectric layer 216 provided on the gate electrode 214, and the dielectric layer 216. An organic semiconductor 218 provided, and a drain electrode 222 and a source electrode 220 provided on the organic semiconductor 218. Transistor 210 is electrically connected to pixel electrode 200, column electrode 204, and row electrode 206. The pixel electrode 200 is connected to the drain electrode of the transistor 210. The column electrode 204 is connected to the source electrode of the transistor 210.

Substrate 212 may have flexibility. For example, the substrate 212 can be made of a polymer such as polyethylene terephthalate (PET, polyester), polyethersulfone (PES), polyimide film (Kapton, Upilex), or polycarbonate. Alternatively, substrate 212 may be made of an insulator, such as undoped silicon, glass, or other plastic. The substrate 212 may be patterned to function as an electrode. Alternatively, substrate 212 may be a metal foil insulated from gate electrode 214 by a non-conductive material. Gate electrode 214, source electrode 220, and drain electrode 222, such as metal, such as gold. Alternatively, the electrodes 214, 220, 222 may be made of a conductive conductor such as polythiopine or polyaniline, printed conductors such as polymer films containing metal particles such as silver or nickel, graphite or some other conductive carbon material, Or printed conductors such as polymer films containing conductive oxides such as tin oxide or indium tin oxide, or metal electrodes such as aluminum or gold.

For example, dielectric layer 216 may comprise a silicon dioxide layer. Alternatively, dielectric layer 216 may be a polyimide and its derivatives or poly-vinyl phenols, polymethylemethacrylate, polyvinylidene dimples of sol-gel organosilicon glass. Organic / inorganic synthetic materials such as polyvinyldenedifluorided, inorganic oxides such as metal oxides, inorganic nitrides such as silicon nitride, or organic-substituted silicon oxides. The dielectric layer 216 may include a benzocyclobutene (BCB) derivative, spin-on glass, or a dielectric colloidal material dispersed in a binder or solvent sold by Dow Chemical Company (Midland, US). have.

The semiconductor layer 218 may be an organic polymer. In one embodiment, the organic semiconductor comprises a polymer or oligomeric semiconductor. Examples of suitable polymer semiconductors include polythiopins, poly (3-alkyl), alkyl-substituted oligothioffins, polythienylenevinylene, poly (para-phenylenevinylene) and doped forms of such polymers, and the like. It includes, but is not limited to. Examples of suitable oligomeric semiconductors are alphahexathienylene. Organic Field-Effect Transistor, Adv. Master of Horowitz . , 10, No. 5, p. 365 (1998) describes the use of unsubstituted oligothioffins and alkyl-substituted oligothioffins in transistors. Field effect transistors composed of Reggioregular Poly (3-hexylthioffin) as a semiconductor layer include SOluble and Processable Regioregular Poly (3-hexylthiophene) for Thin Film Field-Effect Transistor Applications with High Mobility , Appl. Phys. Lett 69 (26), p. 4108 (December 1996). Field effect transistors of α-hexathienylene are described in US Pat. No. 5,659,181.

In another embodiment, organic semiconductor 218 includes a carbon based compound. Examples of suitable carbonaceous compounds include pentacene, phthalocyanine, benzodithiophene, fullerene, buckminsterfullerene, tetracyanonaphthoquinone, and tetrakisi Methylranimoethylene, and the like, but is not limited thereto. The materials provided above for forming a substrate, dielectric layer, electrode, or semiconductor layer are exemplary only. Other suitable materials known to those skilled in the art having the same properties as described above can also be used in accordance with the present invention.

The field effect transistor types provided in FIGS. 10 and 11 are merely exemplary. Other transistor designs known to those skilled in the art can be used in accordance with the present invention. For example, a top gate structure can be used in accordance with the present invention, wherein the source and drain electrodes are positioned in contact with the substrate, covered with a dielectric layer, and in turn covered by a semiconductor and gate electrode.

According to the present invention, the electrodes, nonlinear devices such as the transistors of FIGS. 10 and 11, logic and driving circuits, etc., are not limited thereto, but deposition, evaporation, lithography, printing, coating, etc. It may be prepared by a suitable manufacturing process known to those skilled in the art including. For example, the entire transistor of an organic substrate is co-owned and can be printed entirely as described in US patent application Ser. No. 09 / 289,036, which is incorporated by reference. As another example, a transistor can be fabricated on a first substrate and then removed, co-owned, and provided on a substrate of a circuit layer as described in US patent application Ser. No. 09 / 338,412, which is incorporated by reference. have.

Although the present invention has been described in detail with reference to certain preferred embodiments, those skilled in the art will recognize that various modifications may be made in form and detail without departing from the spirit and scope of the invention as defined by the appended claims. It will be appreciated.

Claims (34)

a) a modulation layer comprising a first substrate and an electro-optical material provided in contact with said first substrate, said modulation layer providing a modulation layer capable of changing the viewing state upon application of an electric field; b) a pixel layer comprising a second substrate, a plurality of pixel electrodes provided on the front side of the second substrate, and a plurality of contact pads provided on the back side of the second substrate, the pixel electrodes being connected to the contact pads with the second layer; Providing a pixel layer connected through a via extending through the substrate; c) providing a circuit layer comprising a third substrate and one or more circuit components; And d) integrating said modulation layer, said pixel layer, and said circuit layer to form an electro-optical device. The method of claim 1, Step d) is, d1) integrating the pixel layer and the modulation layer to form a sub-assembly; And d2) integrating said circuit layer and said sub-assembly to form an electro-optical device. The method of claim 1, Wherein said electro-optical material comprises a plurality of capsules, each capsule comprising a plurality of particles dispersed in a fluid. The method of claim 3, wherein Wherein the plurality of particles comprises electrophoretic particles. The method of claim 1, And said electro-optical material comprises a liquid crystal. The method of claim 1, Wherein said electro-optic material comprises a plurality of capsules, each capsule comprising a dichroic sphere dispersed in a fluid. The method of claim 1, And wherein said modulation layer comprises a flexible first substrate. The method of claim 1, And the modulation layer comprises an organic first substrate. The method of claim 1, And wherein said modulation layer comprises a first substrate and a transparent common electrode provided on said first substrate. The method of claim 1, And said pixel layer comprises an insulating second substrate. The method of claim 1, And forming the pixel layer by printing a conductive material on the front side of the second substrate to form the pixel electrode. The method of claim 1, Forming the pixel layer by depositing a conductive material on the front surface of the second substrate to form the pixel electrode. The method of claim 1, Providing the plurality of via holes through the second substrate and filling the via holes with a conductive material to form the pixel layer. The method of claim 2, Said step d1) comprises encapsulating said pixel layer and said modulation layer. The method of claim 2, And said step d1) comprises sealing together an edge portion of said pixel layer and an edge portion of said modulation layer. The method of claim 2, And said step d1) comprises integrating said pixel layer and said modulation layer by providing a front side of said pixel portion in contact with an electro-optical material of said modulation layer. The method of claim 2, And said step d2) comprises adhering said circuit board layer and said sub-assembly. The method of claim 2, And said step d1) comprises inserting an adhesive layer between said pixel layer and said modulation layer. The method of claim 2, Said step d2) comprising adhering said circuit layer to the back side of said pixel layer. The method of claim 19, Said step d2) comprising adhering said circuit layer and said sub-assembly through thermocompression bonding, thermal atom bonding, and mechanical bonding. The method of claim 19, Said step d2) comprising adhering said circuit layer and said sub-assembly by inserting an adhesive between said circuit layer and said sub-assembly. The method of claim 21, And said step d2) comprises inserting an adhesive layer comprising an anisotropic conductive material between said circuit layer and said sub-assembly. The method of claim 2, And printing the adhesive layer in contact with the back side of the pixel layer around the contact pad before performing step d2). The method of claim 1, Wherein the circuit layer comprises at least one data line driver, a selection line driver, a power supply, a sensor, a logic element, a memory device, and a communication device. The method of claim 2, Said step a) comprises providing a first modulation layer and a second modulation layer, Said step b) comprises providing a first pixel layer and a second pixel layer, The step d1) includes integrating the first pixel layer and the first modulation layer to form a first assembly, and integrating the second pixel layer and the second modulation layer to form a second assembly; , And said step d2) comprises positioning said circuit layer between said first assembly and said second assembly. The method of claim 1, Testing the modulation layer and the circuit layer prior to performing step d). The method of claim 1, And the circuit layer comprises a plurality of nonlinear elements. The method of claim 1, Wherein said circuit layer comprises a plurality of organic based field effect transistors. The method of claim 1, And printing a field effect transistor array of organic substrates on the front side of the third substrate of the circuit layer. The method of claim 2, The circuit layer includes a plurality of contacts provided on the front side of the third substrate, and step d2) integrates the modulation layer and the sub-assembly such that the contacts of the circuit layer are provided in contact with the contact pads of the pixel layer. The method comprising the step of. The method of claim 1, Step d) is, d1) integrating the pixel layer and the circuit layer to form a sub-assembly, and d2) integrating said modulation layer with said sub-assembly to form an electro-optical device. An electro-optical device made by the method of claim 1. An electro-optical device made by the method of claim 2. An electro-optical device made by the method of claim 31.