DISPLAY ELEMENT AND ELECTRONIC DEVICE

The present disclosure provides a display element that is capable of reducing the area of a substrate including light emitting elements and has an enhanced stability of connection of a drive integrated circuit to the substrate and a flexible substrate, and also provides an electronic device using the display element. The display element includes: a substrate that includes a light emitting element disposed therein, and has a light emitting surface; a drive integrated circuit including a drive circuit that controls driving of the light emitting element; and a flexible substrate having a connecting terminal. In the display element, the drive integrated circuit is disposed on one surface of the substrate, and the flexible substrate is disposed on the side of a surface of the drive integrated circuit, the surface not facing the substrate.

TECHNICAL FIELD

The present disclosure relates to a display element and an electronic device.

BACKGROUND ART

A known display element includes a substrate having light emitting elements on a base substrate, and further includes a drive integrated circuit and a flexible substrate (flexible integrated circuit; FPC) disposed on the same surface of the substrate. In such a display element, the area of the substrate is required to be sufficiently large to ensure the region for accommodating the drive integrated circuit and the flexible substrate, in addition to the region for accommodating the light emitting elements. Therefore, there is room for improvement in the display element, in terms of a smaller area for the substrate including the light emitting elements.

An electro-optical device disclosed in Patent Document 1 includes: an electro-optical panel in which a plurality of EL elements is arranged; an IC element that is connected to the electro-optical panel and includes a circuit for driving or controlling the EL elements; and an FPC on which the IC is mounted, and wiring lines electrically connected to the circuit in the IC element are provided. The IC element in the electro-optical device has first terminal pads connected to the wiring lines on the FPC, and second terminal pads connected to the wiring lines on the electro-optical panel.

CITATION LIST

Patent Document

SUMMARY OF THE INVENTION

Problems to be Solved by the Invention

In the electro-optical device disclosed in Patent Document 1, dimensional accuracy is required for the first terminal pads and the second terminal pads. Further, to stabilize a state in which the FPC and the IC element are pressure-bonded to the electro-optical panel with an anisotropic conductive film, it is required to consider the difference in elastic modulus between the FPC and the IC element. Therefore, in the electro-optical device disclosed in Patent Document 1, there is room for improvement in the stability of connection of the IC element to both the electro-optical panel and the FPC.

The present disclosure has been made in view of the aspects described above, and an object of the present disclosure is to provide a display element that is capable of reducing the area of a substrate including light emitting elements and has an enhanced stability of connection of a drive integrated circuit to the substrate and a flexible substrate, and an electronic device using the display element.

Solutions to Problems

The present disclosure relates to, for example,(1) a display element including:a substrate that includes a light emitting element disposed therein, and has a light emitting surface;a drive integrated circuit including a drive circuit that controls driving of the light emitting element; and a flexible substrate, in which the drive integrated circuit is disposed on one surface of the substrate, and the flexible substrate is disposed on a surface of the drive integrated circuit, the surface not facing the substrate.

The present disclosure also relates to(2) a display element including:a substrate that includes a light emitting element disposed therein, and has a light emitting surface;a drive integrated circuit including a drive circuit that controls driving of the light emitting element; anda flexible substrate,in which the drive integrated circuit is disposed on one surface of the substrate, andthe flexible substrate is disposed on a surface of the substrate, the surface being opposite to the light emitting surface.

The present disclosure may relates to(3) a display element including:a substrate that includes a light emitting element disposed therein, and has a light emitting surface;a drive integrated circuit including a drive circuit that controls driving of the light emitting element; anda conductive connecting member that relays electrical connection with outside,in which the drive integrated circuit is disposed on one surface of the substrate, andthe conductive connecting member is disposed on a surface of the drive integrated circuit, the surface not facing the substrate.

The present disclosure may also relates to, for example, (4) an electronic device including the above display device of (1).

MODE FOR CARRYING OUT THE INVENTION

In the description below, an example and the like according to the present disclosure will be described with reference to the drawings. Note that explanation will be made in the following order. In the present specification and the drawings, components having substantially the same functional configurations are denoted by the same reference signs, and explanation of them will not be repeated.

Note that the explanation will be made in the following order.1. First Embodiment2. Second Embodiment3. Third Embodiment4. Fourth Embodiment5. Fifth Embodiment6. Sixth Embodiment7. Example Applications

The following description concerns preferred specific examples of the present disclosure, and the contents of the present disclosure are not limited to these embodiments and the like. Also, in the following description, directions such as forward and backward, rightward and leftward, and upward and downward directions are used for ease of explanation, but the contents of the present disclosure are not limited by these directions. In examples inFIGS.1and2, it is assumed that the Z-axis direction is the upward and downward directions (the upper side is the +Z direction, and the lower side is the −Z direction), the X-axis direction is the forward and backward directions (the front side is the +X direction, and the back side is the −X direction), and the Y-axis direction is the rightward and leftward directions (the right side is the +Y direction, and the left side is the −Y direction). The explanation will be made on the basis of these directions. The same applies inFIGS.3to9. A relative dimensional ratio of the size and thickness of each layer illustrated in each drawing ofFIG.1and the like is shown for convenience, and does not limit any actual dimensional ratio. This applies in each drawing ofFIGS.2to9regarding the definitions of these directions and the dimensional ratios.

Examples of display elements according to the present disclosure include a display module, an illumination module, and the like. In the following first to sixth embodiments, cases where a display element is a display module will be described.

In a display element according to the present disclosure, a light emitting element provided in the display region described later is not limited to any particular light emitting element, and examples thereof include a light emitting diode (LED), an organic light emitting diode (OLED), and the like. In the following first to sixth embodiments, cases where a light emitting element is an OLED will be described as examples. In the present disclosure, an OLED is referred to as an organic electroluminescence (EL) element in some cases. Further, a display element including an OLED as a light emitting element is referred to as an organic EL display element in some cases.

1 First Embodiment

[1-1 Configuration of a Display Element]

An organic EL (OLED) display element (hereinafter referred to simply as a “display element10”) as an example of a display element according to an embodiment of the present disclosure is described below with reference toFIGS.1and2and others.FIG.1is an exploded perspective view illustrating an example configuration of the display element10.FIG.2is a cross-sectional view for explaining the display element. As illustrated inFIGS.1and2, the display element10includes a substrate11that has a light emitting element104and a light emitting surface D.

(Display Region and Outer Region)

In the display element10, a light emitting region10A and an outer region10B are defined on the side of the light emitting surface D. The light emitting region10A is defined as the region where light generated from a plurality of light emitting elements104is emitted to the outside. The outer region10B is defined as a region outside the light emitting region10A on the surface of the substrate11on the side of the light emitting surface D. In the example inFIG.1, the light emitting region10A is formed as a rectangular region, and the region defined as a rectangular annular region outside the light emitting region10A is the outer region10B. The position of the outer edge of the light emitting region10A is the position of the inner peripheral edge of the outer region10B, and the light emitting region10A and the outer region10B are in contact with each other at the boundary. Note that, among the surfaces of the substrate11, the light emitting surface D indicates the surface from which light generated from the light emitting elements104is extracted to the outside in the display element10.

In the description below, a case where the display element10performs display by a top emission method is explained as an example. The top emission method indicates a method by which the light emitting elements104are disposed on the side of the light emitting surface D rather than the side of a base substrate11A. Accordingly, in the display element10, the base substrate11A is located on the back surface side of the display element10, and the direction (+Z direction) from the base substrate11A toward the light emitting elements104described later is the direction toward the front surface side (upper surface side) of the display element10. In the display element10, light generated from the light emitting elements104is directed in the +Z direction, and is emitted to the outside. In the description below, in each of the layers constituting the display element10, the surface on the display surface side in the display region (light emitting region10A) of the display element10will be referred to as the first surface (upper surface), and the surface on the back surface side of the display element10will be referred to as the second surface (lower surface). Note that this does not prohibit any case where the display element10according to the present disclosure is of a bottom emission type. The display element10is also applicable to a bottom emission type. By a bottom emission method, light generated from the light emitting elements104is directed in the −Z direction, and is emitted to the outside.

In the example of the display element10illustrated inFIG.1, one pixel is formed with a combination of a plurality of sub-pixels corresponding to a plurality of color types. In this example, the three colors of red, green, and blue are defined as the plurality of color types, and the three types of sub-pixel101R, sub-pixel101G, and sub-pixel101B are provided as sub-pixels. The sub-pixel101R, the sub-pixel101G, and the sub-pixel101B are a red sub-pixel, a green sub-pixel, and a blue sub-pixel, respectively, and display the red color, the green color, and the blue color, respectively. However, the example inFIG.1is an example, and does not limit the color types of the plurality of sub-pixels. Further, the wavelengths of light beams corresponding to the respective color types of red, green, and blue can be determined as wavelengths in the range of 610 nm to 650 nm, the range of 510 nm to 590 nm, and the range of 440 nm to 480 nm, respectively, for example. Furthermore, examples of layouts of the individual sub-pixels101R,101G, and101B include a layout in which combinations of sub-pixels101formed in a striped shape are arranged in a matrix. In the example inFIG.1, the sub-pixels101R,101G, and101B are two-dimensionally disposed in the light emitting region10A.

In the description below, the term “sub-pixels101” is used in a case where the sub-pixels101R,101G, and101B are not particularly distinguished from one another.

The substrate11(hereinafter also referred to as the principal board) includes a circuit board15in which a circuit layer12for driving a plurality of light emitting elements104is provided on the base substrate11A, and the plurality of light emitting elements104on the circuit board15.

The circuit layer12formed on the circuit board15forming the principal board includes a circuit structure13forming a circuit, and an insulating layer14. Examples of the circuit formed by the circuit structure13include a control circuit that controls driving of the light emitting elements104, and a power supply circuit that supplies power to the plurality of light emitting elements104(neither the control circuit nor the power supply circuit is shown in the drawings). InFIG.2, for ease of explanation, the circuit structure13is comprehensively illustrated as one layer. The circuit board15forming the substrate11as the principal board corresponds to a so-called backplane. This also applies inFIGS.4to9.

The base substrate11A may be formed with glass or resin having low moisture and oxygen permeability, or may be formed with a semiconductor in which a transistor or the like is easily formed, for example. Specifically, the base substrate11A may be a glass substrate, a semiconductor substrate, a resin substrate, or the like. The glass substrate contains high strain point glass, soda glass, borosilicate glass, forsterite, lead glass, quartz glass, or the like, for example. The semiconductor substrate contains amorphous silicon, polycrystalline silicon, monocrystalline silicon, or the like, for example. The resin substrate contains at least one material selected from the group consisting of polymethyl methacrylate, polyvinyl alcohol, polyvinyl phenol, polyethersulfone, polyimide, polycarbonate, polyethylene terephthalate, polyethylene naphthalate, and the like, for example.

A plurality of contact plugs17for connecting the light emitting elements104and the circuit in the circuit structure13of the circuit layer12is provided on the first surface of the base substrate11A. The insulating layer14is formed around the circuit structure13and the contact plugs17formed on the base substrate11A.

The insulating layer14is formed with an organic material or an inorganic material, for example. The organic material contains at least one material of polyimide or acrylic resin, for example. The inorganic material contains at least one material of silicon oxide, silicon nitride, silicon oxynitride, and aluminum oxide, for example.

A contact plug17can be formed as a portion in which a conductive structure is formed in a hole portion formed in the insulating layer14, for example. The contact plug17make the light emitting element104and the circuit structure13electrically continuous with each other. In the conductive structure, a layer of a conductive material is formed on the inner peripheral surface of the hole portion in some cases, and the hole portion is filled with a conductive material in other cases. As the conductive material, a conductive material that is similar to the conductive material forming a through hole115A to be the first conductive structure115described later can be used. InFIG.2, a contact plug17is formed for each pixel, for ease of explanation. However, a contact plug17is preferably formed for each sub-pixel101.

In the display element10, a plurality of light emitting elements104is disposed on the first surface side of the substrate11. In the examples inFIG.2and others, the light emitting elements104are organic electroluminescence elements (organic EL elements or OLED elements). Also, in the example inFIG.2, for ease of explanation, the plurality of light emitting elements104is formed for each pixel. However, the plurality of light emitting elements104is normally provided for each sub-pixel so as to correspond to the individual sub-pixels101R,101G, and101B. The plurality of light emitting elements104is two-dimensionally arranged in a prescribed arrangement pattern such as a matrix form or the like, for example.

The light emitting elements104each include a first electrode, an organic layer, and a second electrode (not shown in the drawings). The first electrode, the organic layer, and the second electrode are stacked in this order from the side of the base substrate11A in the direction from the second surface toward the first surface.

A plurality of first electrodes is provided on the side of the first surface of the base substrate11A. The first electrodes are electrically connected to the contact plugs17(not illustrated). The first electrodes are connected for the respective sub-pixels101. The first electrodes are electrically separated from each other for the respective sub-pixels101by an insulating layer described later. The first electrodes are anode electrodes. The first electrodes each include at least one of a metal layer or a metal oxide layer. The first electrodes may each include a single layer film of a metal layer or a metal oxide layer, or a film stack of a metal layer and a metal oxide layer.

The metal layer contains at least one metal element selected from the group consisting of chromium (Cr), gold (Au), platinum (Pt), nickel (Ni), copper (Cu), molybdenum (Mo), titanium (Ti), tantalum (Ta), aluminum (Al), magnesium (Mg), iron (Fe), tungsten (W), and silver (Ag), for example. The metal layer may contain the at least one metal element described above as a constituent element of an alloy. Specific examples of the alloy include an aluminum alloy and a silver alloy. Specific examples of the aluminum alloy include AlNd and AlCu, for example.

The metal oxide layer contains at least one of a mixture of indium oxide and tin oxide (ITO), a mixture of indium oxide and zinc oxide (IZO), or titanium oxide (TiO), for example.

The organic layer is disposed between the first electrode and the second electrode. The organic layer may be provided as a layer common to the sub-pixels101, or may be provided as an independent layer for each of the sub-pixels101R,101G, and101B. As the organic layer, an organic layer that generates red light, an organic layer that generates blue light, an organic layer that generates green light, or the like may be adopted in accordance with the sub-pixel101R,101G, or101B. Alternatively, in a case where the organic layer is a layer common to the sub-pixels101, an organic layer that generates white light may be adopted as the organic layer, for example.

The organic layer has a configuration in which a hole injection layer, a hole transport layer, a light emitting layer, and an electron transport layer are stacked in this order in the direction from the first electrode toward the second electrode, for example. An electron injection layer may be disposed between the electron transport layer and the second electrode. The electron injection layer is for enhancing electron injection efficiency. Note that the configuration of the organic layer is not limited to this, and layers other than the light emitting layer are provided as necessary. The hole injection layer is a buffer layer for enhancing efficiency of hole injection into the light emitting layer and reducing leakage. The hole transport layer is for enhancing efficiency of hole transport to the light emitting layer. The electron transport layer is for enhancing efficiency of electron transport to the light emitting layer.

The light emitting layer generates light when recombination of electrons and holes is caused by an electric field. The light emitting layer is an organic light emitting layer containing an organic light emitting material.

In the light emitting element104, the second electrode is disposed to face the first electrode. The second electrode may be provided for each sub-pixel101, or may be provided as an electrode common to a plurality of sub-pixels101. The second electrode is a cathode electrode. The second electrode is preferably a transparent electrode having transparency to light generated in the organic layer. The transparent electrode herein may be a transparent electrode formed with a transparent conductive layer, or a transparent electrode formed with a stack structure including a transparent conductive layer and a semi-transmissive reflective layer.

The transparent conductive layer can be formed with a metal oxide, for example. Specifically, an example of the material of the transparent conductive layer can be a material containing at least one of a mixture of indium oxide and tin oxide (ITO), a mixture of indium oxide and zinc oxide (IZO), or zinc oxide (ZnO).

The semi-transmissive reflective layer can be formed with a metal layer, for example. Specifically, examples of the material of the semi-transmissive reflective layer can include a material including at least one metal element selected from the group consisting of magnesium (Mg), aluminum (Al), silver (Ag), gold (Au), and copper (Cu). The metal layer may contain the at least one metal element described above as a constituent element of an alloy. Specific examples of the alloy include an MgAg alloy, an AgPdCu alloy, and the like.

As illustrated inFIG.2, a protective layer18is formed so as to cover the first surfaces of the light emitting elements104. The protective layer18shields the light emitting elements104from the outside air, and reduces moisture infiltration into the light emitting elements104from the external environment.

The protective layer18is formed with an insulating material. As the insulating material, thermosetting resin or the like can be used, for example. Other than that, the insulating material may be SiO, SiON, AlO, TiO, or the like. In this case, examples of the protective layer18include a CVD film containing Sio, SiON, or the like, and an ALD film containing AlO, TiO, SiO, or the like. Note that a CVD film means a film formed by chemical vapor deposition. An ALD film means a film formed by atomic layer deposition. Note that, inFIG.2, for ease of explanation, the protective layer18, the insulating layer formed between the adjacent first electrodes, and the layer filling the gap between color filters16and a counter substrate19are described as an integrated layer structure. That is, as illustrated inFIG.2, the protective layer18is also formed on the second surface side of the light emitting elements104, and is also formed between the color filters16and the counter substrate19.

The color filters16may be provided on the light emitting elements104, as necessary. In the example inFIG.2, the color filters16corresponding to the color types of the sub-pixels101are provided. In a sub-pixel101R, a red-color filter16R is provided as the color filter16. In a sub-pixel101G, a green-color filter16G is provided as the color filter16. In a sub-pixel101B, a blue-color filter16B is provided as the color filter16. Also, lenses or the like may be further provided. Note that a layer structure similar to that of the protective layer18may also be formed between the color filters16and the counter substrate19.

As illustrated in the examples inFIGS.1and2and others, the counter substrate19may be provided on the first surface side of the light emitting elements104. As the material of the counter substrate19, the material of the base substrate11A of the substrate11or the like can be used. For example, a glass substrate can be used as the counter substrate19. The material of the glass substrate is not limited to any particular material, as long as the glass substrate is formed with a material that transmits light emitted from the organic layer. Examples of the material of the glass substrate include various glass substrates such as high strain point glass, soda glass, borosilicate glass, and lead glass, and quartz substrates.

(Electrode Pads on the Substrate Side)

Electrode pads21electrically connected to the drive integrated circuit110described later are formed on the first surface side of the substrate11. The electrode pads21on the side of the substrate11are provided so as to be electrically connectable to the drive integrated circuit110at a position where the drive integrated circuit110is disposed in the outer region10B in a planar view of the substrate11. Each electrode pad21is formed in a layer-like form in the example inFIG.2. Such electrode pads21can be formed by a sputtering method and an etching method, for example. The material of the electrode pads21connected to the drive integrated circuit110can be formed with a conductive material, for example. Examples of the conductive material include metal materials such as copper, aluminum, and silver. The electrode pads21are provided in the insulating layer14disposed on the base substrate11A. Further, at least a partial region (an exposed surface21A) of each electrode pad21is exposed on the upper surface side (the same surface side as the light emitting surface D) of the electrode pad21. On the exposed surface21A of the electrode pad21, the electrode pad21is electrically connected to the drive integrated circuit110described later, as illustrated inFIG.2. In the example inFIG.2, the electrode pads21are electrically connected to the drive integrated circuit110via projecting electrodes118.

The display element10includes the drive integrated circuit110on one surface side of the substrate11. In the examples inFIGS.1and2, the drive integrated circuit110is provided on the side of the light emitting surface D of the substrate11. The drive integrated circuit110is an integrated circuit (IC) in which a drive circuit that controls driving of the light emitting elements104is formed. In the examples inFIGS.1,2, and3, the drive integrated circuit110is a display driver integrated circuit (DDIC) that controls driving of the circuit of the substrate11. The DDIC controls a light-emitting state of the light emitting surface D. In the examples inFIG.1and others, the drive integrated circuit110is disposed in the outer region10B.

In the example inFIG.3, the drive integrated circuit110includes a substrate111(sometimes referred to as a sub board) having a structure in which a drive circuit layer112is formed on a base substrate111A. That is, the substrate111is a substrate on which a drive circuit formed in the drive circuit layer112is mounted. As the base substrate111A, a glass substrate, a semiconductor substrate, a resin substrate, or the like may be used, like the base substrate11A forming the substrate11. As the base substrate111A, a silicon substrate or the like can be suitably used.

As illustrated inFIG.3, the drive circuit layer112has a structure in which a drive circuit is disposed inside the insulating layer114.FIG.3shows wiring lines113that constitute the drive circuit, for example. As the material of the insulating layer114, a material similar to the insulating layer14provided on the base substrate11A may be used.

Conductive structures that relay electrical connection with a flexible substrate150are provided in the drive integrated circuit110. The conductive structures ire referred to as first conductive structures115. The first conductive structures115electrically connect the drive circuit of the drive integrated circuit110and the circuit of the flexible substrate150. In the display element10according to the first embodiment, through holes115A are formed as the first conductive structures115.

The through holes115A as the first conductive structures115each have a structure that makes one end115A1and the other end115A2thereof electrically continuous with each other in the thickness direction (Z-axis direction) of the drive integrated circuit110. Each through hole115A extends in the direction from the side of an opposing surface110A (a so-called active surface) facing the substrate11toward the side of a non-opposing surface110B (the surface opposite to the active surface). The through holes115A are connected to the wiring lines113constituting the drive circuit at the tip portion on the side of the opposing surface110A, and the tip portion on the side of the non-opposing surface110B extends to the non-opposing surface110B of the drive integrated circuit110or to a position in the vicinity thereof. In the examples inFIGS.2and3, the through holes115A are formed as holes penetrating the base substrate111A. The through holes115A form through electrodes having conductivity. In a case where the base substrate111A is a silicon substrate, the through holes115A are so-called through-silicon vias (TSVs).

The number and the positions of the through holes115A are determined in accordance with the number and the positions of electrode pads117on the side of the non-opposing surface110B.

The through holes115A shown as examples inFIGS.2and3each have a solid structure. Such a through hole115A can have a structure in which a layer (metal layer) of a metal material is formed inside the hole constituting the through hole115A, and the inner peripheral surface side of the metal layer is further filled with a metal material of the same type as or a different type from the material of the metal layer, for example. The metal material is not limited to any particular material as long as the metal material is a conductive material, and examples thereof include copper, tungsten, and the like. However, the materials mentioned herein are merely examples. The through holes115A are only required to be through electrodes, and the structure of each through hole115A is not limited to any particular one. For example, each through hole115A may have a hollow structure in which a metal layer is formed inside a hole. The same applies to through holes136A, first substrate through hole125A, second substrate through hole130A, third substrate through hole145A, and vias145B, which will be described later.

(Electrode Pads of the Drive Integrated Circuit)

In the drive integrated circuit110illustrated inFIG.2, electrode pads116and117are provided on the side of the opposing surface110A and the side of the non-opposing surface110B, respectively. The electrode pads116provided on the side of the opposing surface110A are electrically connected to the projecting electrodes118on one surface side (second surface side) thereof. Also, the electrode pads116are electrically connected to the drive circuit of the drive circuit layer112on the other surface side (first surface side).

The structure of each of the electrode pad116provided on the side of the opposing surface110A is not limited to any particular structure, and a metal layer formed with a metal material such as aluminum can be used, for example. In the examples inFIGS.2and3, a plurality of electrode pads116on the side of the opposing surface110A is provided at positions corresponding to the electrode pads21of the substrate11.

The electrode pads117provided on the side of the non-opposing surface110B are electrically connected to the through holes115A on one surface side (second surface side). Also, the electrode pads117are electrically connected to the flexible substrate150on the other surface side (first surface side), which is the side of exposed surfaces117A.

The structure of each of the electrode pads117on the side of the non-opposing surface110B may be a structure similar to that of each electrode pad116on the side of the opposing surface110A. Further, each electrode pads117on the side of the non-opposing surface110B may include a layer formed with a metal material forming the through holes115A. In this case, the electrode pads117may be formed integrally with the through holes115A. Also, in this case, the electrode pads117are preferably subjected to nickel/gold plating on the side of the exposed surfaces117A. In this manner, stability of the bonding between the electrode pads117and the flexible substrate150can be enhanced.

The projecting electrodes118are disposed between the substrate11and the drive integrated circuit110. As the projecting electrodes118, so-called bumps are suitably used. The projecting electrodes118are preferably disposed on the electrode pads116on the side of the opposing surface110A of the drive integrated circuit110. In the example inFIG.2, the projecting electrodes118are disposed on a predetermined region including exposed surfaces116A of the electrode pads116, and are electrically connected to the electrode pads116. The projecting electrodes118are preferably structures formed by a method selected from among electrolytic plating, electroless plating, and a stud bump forming method. However, this does not exclude the projecting electrodes118being formed by a method other than those methods.

Examples of the material of the projecting electrodes118include Au-, Cu-, Al-, Ni-, and Sn-based solder alloys, a stack structure of a plurality of these metals, and the like.

An insulating layer119is provided on the side of the opposing surface110A of the drive integrated circuit110. The insulating layer119fills the gaps between the adjacent electrode pads116in a planar view of the drive integrated circuit110. Further, as illustrated inFIG.2, the insulating layer119may be formed so as to protrude onto the surfaces (second surfaces) of the electrode pads116so as to cover the outer peripheral edges of the electrode pads116. However, openings119A are formed in the insulating layer119, and the electrode pads116are exposed through the openings119A. The surface portions of the electrode pads116exposed through the openings119A are the exposed surfaces116A.

(Method of Connection between the Drive Integrated Circuit and the Substrate)

The drive integrated circuit110is electrically connected to the circuit of the circuit layer12of the substrate11. The method of connection between the substrate11and the drive integrated circuit110is not limited to any particular method. Examples of the connection method include a method that uses an anisotropic conductive film120(ACF) formed with a resin film containing conductive particles120A, as illustrated inFIG.2, for example. This method can be implemented as described below, for example. The drive integrated circuit110is positioned so that the projecting electrodes118of the drive integrated circuit110face the electrode pads21on the side of the substrate11via the anisotropic conductive film120. The projecting electrodes118and the electrode pads21are then pressure-bonded via the anisotropic conductive film120. At the time of the pressure bonding, the circuit of the substrate11and the drive circuit of the drive integrated circuit110are electrically connected via the conductive particles120A contained in the anisotropic conductive film120. Note that, at this point of time, the surface (active surface) of the drive integrated circuit110on which the drive circuit layer112is formed is directed to the side of the substrate11, and the drive integrated circuit110is flip-chip mounted on the substrate11.

Note that the method of connection between the substrate11and the drive integrated circuit110is not limited to the above method using the anisotropic conductive film120. As the method of connection between the substrate11and the drive integrated circuit110, a method that uses a non-conductive adhesive film (non-conductive film; NCF) to secure the projecting electrodes118and the electrode pads21that are connected directly to each other, a method that uses an anisotropic conductive film and a non-conductive adhesive film in combination, solder connection, or the like may be used, for example.

The flexible substrate150is a so-called flexible printed circuit board (flexible printed circuits; FPC). The flexible substrate150relays electrical connection with an external device or the like. An example of the flexible substrate150may be a stack sheet including a base material layer151, a circuit unit152formed on the base material layer151, and a cover layer153covering the circuit unit152, as illustrated inFIG.1. An exposed portion154is formed in the cover layer153at a predetermined position on one end side of the flexible substrate150. In the flexible substrate150, wiring portions of the circuit unit152are exposed through the exposed portion154, and the exposed wiring portions serve as connecting terminals155. The connecting terminals155are then electrically connected to the electrode pads117on the side of the non-opposing surface110B of the drive integrated circuit110. The connecting terminals155of the flexible substrate150are formed in conformity with the layout of the electrode pads117on the side of the non-opposing surface110B. Note that it is preferable that the flexible substrate150has an external connecting terminal (not illustrated) connected to the outside on the end side opposite to the connecting terminals155described above. Note that, inFIG.2andFIGS.4to9, the base material layer151, the circuit unit152, and the cover layer153are shown, for ease of explanation.

(Method of Connection between the Flexible Substrate and the Drive Integrated Circuit)

The flexible substrate150is disposed on the non-opposing surface110B that does not face the substrate11among the surfaces of the drive integrated circuit110. In this case, the connecting terminals155of the flexible substrate150are connected to the electrode pads117of the drive integrated circuit110. The method of connection between the connecting terminals155of the flexible substrate150and the electrode pads117of the drive integrated circuit110is not limited to any particular method. As the method of connection between the connecting terminals155of the flexible substrate150and the electrode pads117, a method that uses an anisotropic conductive film121may be adopted, for example, as in the description of the method of connection between the drive integrated circuit110and the substrate11. This method can be implemented as described below, for example. The connecting terminals155of the flexible substrate150are made to face the electrode pads117of the drive integrated circuit110. The anisotropic conductive film121is interposed between the electrode pads117of the drive integrated circuit110and the connecting terminals155of the flexible substrate150. The drive integrated circuit110, the anisotropic conductive film121, and the flexible substrate150are then pressure-bonded to one another, so that the electrode pads117are electrically connected to the connecting terminals155via conductive particles121A contained in the anisotropic conductive film121. As the drive integrated circuit110and the flexible substrate150are connected in this manner, the circuit unit152of the flexible substrate150is electrically connected to the through holes115A corresponding to the first conductive structures115, and is further electrically connected to the drive circuit layer112of the drive integrated circuit110via the first conductive structures115.

[1-2 Method for Manufacturing the Display Element]

Next, an example of a method for manufacturing the display element10according to the first embodiment is described in detail.

(Preparation of the Substrate)

The base substrate11A is prepared. The circuit layer12, the light emitting elements104, the electrode pads21, and the like are formed on the base substrate11A by a technique such as a sputtering method, a lithography method, etching, or a vapor deposition method as necessary, for example. Thus, the substrate11can be obtained.

(Preparation of the Drive Integrated Circuit)

The base substrate111A is prepared, and the drive circuit layer112is formed by a technique similar to that used in the preparation of the substrate11as appropriate. The electrode pads116are formed on the drive circuit layer112by a sputtering method and an etching technique, for example, and the insulating layer119is formed so as to fill the gaps between the adjacent electrode pads116. At this point of time, the electrode pads116are exposed through the openings119A of the insulating layer119.

The projecting electrodes118are formed at the positions where the electrode pads116are formed, so as to cover the exposed surfaces116A of the electrode pads116. Examples of the method for forming the projecting electrodes118include an electrolytic plating method, an electroless plating method, a stud bump forming method, and the like as described above.

The through holes115A are formed in the drive integrated circuit110. The method for forming the through holes115A is not limited to any particular method. For example, a method that can be adopted is a method by which, before or after the drive circuit layer112is formed on the base substrate111A, a structure in which plugs are embedded in the base substrate111A in a layout corresponding to the layout of the through holes115A from the side of the surface (the opposing surface110A) having the drive circuit layer112formed thereon is formed by an etching method or the like, and the side of the surface (the non-opposing surface110B) opposite to the surface having the drive circuit layer112formed thereon is ground, to expose the plugs. Other than this method, a method by which plugs are formed in the base substrate111A from a surface not having the drive circuit layer112formed thereon may be used, for example. The plugs are columnar structures extending in the thickness direction of the base substrate111A, and have conductivity. Examples of the material of the plugs include metal materials such as copper and tungsten.

The electrode pads117are formed on the side of the surface of the drive integrated circuit110on which the drive circuit layer112is not formed. The electrode pads117can be formed by a sputtering method and an etching method, for example. The electrode pads117are formed in a layout to be in contact with the plugs.

The substrate11and the drive integrated circuit110are then electrically connected. Also, the drive integrated circuit110and the flexible substrate150are electrically connected. The methods described above can be used as the method of connection between the substrate11and the drive integrated circuit110, and the method of connection between the drive integrated circuit110and the flexible substrate150. Thus, the display element10can be obtained.

[1-3 Functions and Effects]

In the display element10according to the first embodiment, the drive integrated circuit110serving as the sub board is provided on the substrate11serving as the principal board, and the flexible substrate150is further provided on the non-opposing surface110B (the surface on the side opposite to the active surface) of the drive integrated circuit110. Thus, according to the first embodiment, the area of the substrate11including the light emitting elements104can be reduced. Also, in the display element10according to the first embodiment, it is easy to form the projecting electrodes118as structures of substantially uniform sizes, and the stability of the connection between the substrate11and the drive integrated circuit110can be enhanced even in a case where the substrate11and the drive integrated circuit110are connected via the anisotropic conductive film120. Further, in a case where the drive integrated circuit110and the flexible substrate150are connected via the anisotropic conductive film120, the stability of the connection between the drive integrated circuit110and the flexible substrate150can also be enhanced.

Also, in the display element10according to the first embodiment, the transmission distance for an electric signal from the circuit of the flexible substrate150to the integrated circuit of the drive integrated circuit110can be shortened, and the transmission rate can be increased. Further, in a case where the first conductive structures115are the through holes115A, the through holes115A easily have structures each having a large cross-sectional area. Accordingly, it is also easy to lower the resistance of the signal transmission path in the display element10, and thus, the transmission rate can be increased.

2 Second Embodiment

[2-1 Configuration of a Display Element]

A display element10according to a second embodiment has a first conductive structure as illustrated inFIG.4.FIG.4is a cross-sectional view schematically illustrating an example of the display element10according to the second embodiment. In the second embodiment, the first conductive structure115has a side-surface wiring line115B1as a wiring line formed on a side surface110C of a drive integrated circuit110. The display element10according to the second embodiment may be designed in a manner similar to that according to the first embodiment, except for the configuration of the first conductive structures115. Therefore, in the description of the second embodiment, explanation of the other components except for the configuration of the first conductive structures115is not made.

As illustrated inFIG.4, the first conductive structure115includes the side-surface wiring line115B1. Also, in the example inFIG.4, the first conductive structure115includes, on the side of the opposing surface110A (the active surface side) with respect to the substrate11, a wiring line (first coupling wiring line115B2) that continues to one end of the side-surface wiring line115B1and is coupled to an electrode pad116on the side of the opposing surface110A. The first conductive structure115includes, on the surface side opposite to the active surface (the side of the non-opposing surface110B), a wiring line (second coupling wiring line115B3) that continues to the other end of the side-surface wiring line115B1and is coupled to an electrode pad117on the side of the non-opposing surface110B. However, this does not prohibit any case where the first conductive structure115excludes at least one of the first coupling wiring line115B2and the second coupling wiring line115B3. The first coupling wiring line115B2illustrated inFIG.4is connected to a side surface of the electrode pad116, and the second coupling wiring line115B3is interposed between the electrode pad117and the base substrate111A. However, this is merely an example, and the position of connection between the first coupling wiring line115B2and the electrode pad116, and the position of connection between the second coupling wiring line115B3and the electrode pad117are not limited to this example.

In the first conductive structure115illustrated in the example inFIG.4, the side-surface wiring line115B1, the first coupling wiring line115B2, and the second coupling wiring line115B3are formed with a metal wiring layer formed on an outer peripheral surface of the drive integrated circuit110. To form such a metal wiring layer, wiring line formation may be performed after dicing as in a molded interconnect device (MID), for example, or a wafer having a through hole formed therein may be cut along the center portion of the through hole, to obtain individual pieces.

The material of the side-surface wiring line115B1, the first coupling wiring line115B2, and the second coupling wiring line115B3is not limited to any particular material, and examples thereof may include aluminum, silver, copper, and the like.

In the example of the display element10according to the second embodiment illustrated inFIG.4, the through hole115A according to the first embodiment is not shown. However, in the display element10according to the second embodiment, the through hole115A may be used in conjunction with the side-surface wiring line115B1as the first conductive structure115.

[2-2 Functions and Effects]

With the display element10according to the second embodiment, effects similar to those of the first embodiment can be achieved.

[3-1 Configuration of a Display Element]

In a display element10according to a third embodiment, as illustrated inFIG.5, a flexible substrate150is provided on the surface side (second surface side) opposite to a light emitting surface D among the surfaces of a substrate11.FIG.5is a cross-sectional view schematically illustrating an example of the display element10according to the third embodiment. In the third embodiment, second conductive structures125, and electrode pads126connected to the second conductive structures125are disposed in the substrate11, and the flexible substrate150is electrically connected to the second conductive structures125via the electrode pads126. Also, in this example, the first conductive structures115and the electrode pads117described in the first embodiment are not shown. Except for these components, the display element10according to the third embodiment may be designed in a manner similar to that according to the first embodiment. Therefore, in the description of the third embodiment, explanation of the other components, except for the configuration of the second conductive structures125and the electrode pads126, and the structure of connection between the flexible substrate150and the second conductive structures125, is not made.

In the substrate11, the second conductive structures125are disposed at positions corresponding to the positions to which the flexible substrate150is connected. The second conductive structures125are conductive structures that have conductivity and relay electrical connection with the drive integrated circuit110. In the display element10according to the third embodiment, substrate through holes are formed as the second conductive structures125. The substrate through holes are called first substrate through holes125A.

The first substrate through holes125A as the second conductive structures125each have a structure that makes one end125A1and the other end125A2of the first substrate through hole125A electrically continuous with each other in the thickness direction of the substrate11. The first substrate through holes125A extend in the direction from the side of the light emitting surface D (first surface side) toward the surface side (second surface side) opposite to the light emitting surface D of the surfaces of the substrate11. The first substrate through holes125A are connected to the electrode pads21connected to the projecting electrodes118of the drive integrated circuit110at the end on the side of the light emitting surface D, and are connected to the electrode pads126connected to the flexible substrate150at the end on the surface side opposite to the light emitting surface D. In the example inFIG.5, the first substrate through holes125A are formed as holes penetrating the base substrate11A, and further continue to the electrode pads21through the insulating layer14.

The first substrate through holes125A form through electrodes having conductivity. In a case where the base substrate11A is a silicon substrate, the first substrate through holes125A are so-called through-silicon vias. The first substrate through holes125A may have a structure similar to that of the through holes115A described in the first embodiment. Also, the first substrate through holes125A can be formed in a manner similar to that for the through holes115A.

The number and the positions of the first substrate through holes125A are determined in accordance with the number and the positions of the electrode pads126.

The electrode pads126are formed on the second surface side of the substrate11. The electrode pads126are formed in a layout corresponding to the connecting terminals155of the flexible substrate150. The electrode pads126are electrically connected to the first substrate through holes125A. The material of the electrode pads126may be similar to the material of the electrode pads117on the first surface of the drive integrated circuit110. Further, the electrode pads126may be formed in a manner similar to that for the electrode pads117.

(Method of Connection between the Flexible Substrate and the Second Conductive Structures)

As the connecting terminals155of the flexible substrate150are connected to the electrode pads126, the connecting terminals155of the flexible substrate150are electrically connected to the second conductive structures125of the substrate11. The method of connection between the connecting terminals155of the flexible substrate150and the electrode pads126is not limited to any particular method. As the method of connection between the connecting terminals155and the electrode pads126, a method that uses an anisotropic conductive film127may be adopted, for example, as in the description of the method of connection between the flexible substrate150and the drive integrated circuit110in the first embodiment. This method can be implemented as described below, for example. The connecting terminals155of the flexible substrate150are made to face the electrode pads126of the substrate11. The anisotropic conductive film127is interposed between the electrode pads126and the connecting terminals155of the flexible substrate150. The substrate11, the anisotropic conductive film127, and the flexible substrate150are then pressure-bonded to one another, so that the electrode pads126are electrically connected to the connecting terminals155via conductive particles127A contained in the anisotropic conductive film127. At this point of time, the circuit of the flexible substrate150is electrically connected to the second conductive structures125, and is further electrically connected to the drive circuit of the drive integrated circuit110from the second conductive structures125via the projecting electrodes118.

[3-2 Method for Manufacturing the Display Element]

Next, an example of a method for manufacturing the display element10according to the third embodiment is described.

(Preparation of the Substrate)

The substrate11can be obtained in a manner similar to that in the first embodiment. In the third embodiment, however, the first substrate through holes125A serving as the second conductive structures125, and the electrode pads126are further formed. For the first substrate through holes, a method similar to the method for forming the through holes115A explained in the description of the method for manufacturing the display element10according to the first embodiment can be used.

(Preparation of the Drive Integrated Circuit)

The drive integrated circuit110can be obtained in a manner similar to that in the first embodiment. In the third embodiment, however, explanation of the method for forming the through holes115A explained in the description of the method for manufacturing the display element10according to the first embodiment is skipped, and explanation of the formation of the electrode pads117is skipped.

The projecting electrodes118are formed at the positions where the electrode pads116are formed, so as to cover the exposed surfaces116A of the electrode pads116. Examples of the method for forming the projecting electrodes118include an electrolytic plating method, an electroless plating method, a stud bump forming method, and the like as described above.

The substrate11and the drive integrated circuit110are then electrically connected. The method of connection between the substrate11and the drive integrated circuit110can be implemented in a manner similar to the method of connection described in the first embodiment. After that, the drive integrated circuit110is bonded to the second surface side of the substrate11, so that the drive integrated circuit110and the flexible substrate150are electrically connected via the second conductive structures125. The method of connection between the drive integrated circuit110and the flexible substrate150via the second conductive structures125may be the method described above. Thus, the display element10can be obtained.

(Relationship between the Thickness of the Counter Substrate and the Thickness of the Drive Integrated Circuit)

In the display element10according to the third embodiment, the counter substrate19and the drive integrated circuit110are disposed on the same surface side of the substrate11(the side of the light emitting surface D in the example inFIG.5). In the display element10, with respect to the position in the vertical direction (the thickness direction (Z-axis direction) of the substrate11), the position of the non-opposing surface110B that does not face the substrate11(the position on the first surface side of the drive integrated circuit110) among the surfaces of the drive integrated circuit110, and the position of the exposed surface of the counter substrate19(the position on the first surface side of the counter substrate19) are preferably aligned. In this case, the distance H1from the first surface (light emitting surface D) of the substrate11to the first surface (non-opposing surface110B) of the drive integrated circuit110is substantially equal to the distance H2from the first surface of the substrate11to the first surface (the surface that does not face the light emitting elements104) of the counter substrate19. Further, since the thickness of the light emitting elements104and the size (height) of the projecting electrodes118are normally of very small values with respect to the thicknesses of the counter substrate19and the drive integrated circuit110in many cases, it is preferable that the thickness of the counter substrate19and the thickness of the drive integrated circuit110are substantially equal. In the process of manufacturing the display element10, the drive integrated circuit110and the flexible substrate150are electrically connected as described above. In this case, the drive integrated circuit110and the flexible substrate150are normally placed on the same stage. At this point of time, the distance H1and the distance H2are almost equal, and thus, the connection between the drive integrated circuit110and the flexible substrate150via the second conductive structures125can be efficiently realized.

[3-3 Functions and Effects]

In the display element10according to the third embodiment, the area of the substrate11can be reduced, the stability of the electrical connection between the substrate11and the drive integrated circuit110can be enhanced, and the stability of the electrical connection between the drive integrated circuit110and the flexible substrate150can also be enhanced, as in the first embodiment.

Also, in the display element10according to the third embodiment, the transmission distance for an electric signal from the circuit of the flexible substrate150to the integrated circuit of the drive integrated circuit110can be shortened, and the transmission rate can be increased.

[4-1 Configuration of a Display Element]

A display element10according to a fourth embodiment differs from the display elements according to the first to third embodiments in that the one surface of the substrate11on which the drive integrated circuit110is disposed is the surface on the side opposite to the light emitting surface D, as illustrated inFIG.6. That is, the drive integrated circuit110is disposed on the surface opposite to the light emitting surface D among the surfaces of the substrate11.FIG.6is a cross-sectional view schematically illustrating an example of the display element10according to the fourth embodiment.

In the display element10according to the fourth embodiment, third conductive structures130, and electrode pads131connected to the third conductive structures130are disposed on the substrate11, and the drive integrated circuit110is electrically connected to the third conductive structures130via the electrode pads131. One end portion of each second conductive structure125described in the third embodiment is connected to the flexible substrate150, but the other end portion of the second conductive structure125is electrically connected to the circuit of the circuit layer12of the substrate11. Except for these components, the display element10according to the fourth embodiment may be designed in a manner similar to that according to the third embodiment. Therefore, in the description of the fourth embodiment, explanation of the other components, except for the configuration of the third conductive structures130and the electrode pads131, and the structure of connection between the drive integrated circuit110and the third conductive structures130, is not made. Note that, in the fourth embodiment, the first conductive structures115described in the first embodiment are not explained, as in the third embodiment. Further, the electrode pads21described in the first embodiment are not explained.

In the substrate11, the third conductive structures130are disposed at positions corresponding to the positions to which the drive integrated circuit110is connected. Like the second conductive structures125described in the third embodiment, the third conductive structures130have conductivity. The third conductive structures130are conductive structures that relay electrical connection with the circuit of the substrate11. In the display element10according to the fourth embodiment, substrate through holes are formed as the third conductive structures130. The substrate through holes are called second substrate through holes130A.

The second substrate through holes130A as the third conductive structures130each have a structure that makes one end and the other end of the second substrate through hole130A electrically continuous with each other in the thickness direction of the substrate11. Like the first substrate through holes125A described in the third embodiment, the second substrate through holes130A extend in the direction from the side of the light emitting surface D (first surface side) toward the surface side (second surface side) opposite to the light emitting surface D of the surfaces of the substrate11. The second substrate through holes130A are connected to the circuit of the circuit layer12at the end on the side of the light emitting surface D, and are connected to the projecting electrodes118of the drive integrated circuit110via the electrode pads131at the end on the surface side opposite to the light emitting surface D. In the example inFIG.5, the second substrate through holes130A are formed as holes penetrating the base substrate11A. In the fourth embodiment, the first substrate through holes125A described above in the third embodiment, and the second substrate through holes130A are formed as substrate through holes in the substrate11. However, the first substrate through holes125A are connected to the connecting terminals155of the flexible substrate150at the end on the surface side opposite to the light emitting surface D, but, unlike those in the case of the third embodiment, the first substrate through holes125A are connected to the circuit of the circuit layer12at the end on the side of the light emitting surface D.

The second substrate through holes130A form through electrodes having conductivity. Like the first substrate through holes125A described in the third embodiment, the second substrate through holes130A are so-called through-silicon vias in a case where the base substrate11A is a silicon substrate. Like the first substrate through holes125A, each of the second substrate through holes130A may have a structure similar to that of the through holes115A described in the first embodiment. Also, the second substrate through holes130A can be formed in a manner similar to that for the through holes115A.

The number and the positions of the second substrate through holes130A are determined in accordance with the number and the positions of the electrode pads131.

In addition to the electrode pads126, the electrode pads131are formed on the second surface side of the substrate11. The electrode pads131are formed in a layout corresponding to the projecting electrodes118of the drive integrated circuit110. The electrode pads131are electrically connected to the second substrate through holes130A. The material of the electrode pads131may be similar to the material of the electrode pads126. Further, the electrode pads131may be formed in a manner similar to that for the electrode pads126.

(Method of Connection between the Drive Integrated Circuit and the Third Conductive Structures)

As the projecting electrodes118of the drive integrated circuit110are connected to the electrode pads131, the drive integrated circuit110is electrically connected to the third conductive structures130. The method of connection between the projecting electrodes118of the drive integrated circuit110and the electrode pads131is not limited to any particular method. As the method of connection between the projecting electrodes118of the drive integrated circuit110and the electrode pads131, a method that uses an anisotropic conductive film132may be adopted, for example, as in the description of the method of connection between the drive integrated circuit110and the substrate11in the first embodiment. This method can be implemented as described below, for example. The projecting electrodes118of the drive integrated circuit110are made to face the electrode pads131of the substrate11. The anisotropic conductive film132is interposed between the substrate11and the drive integrated circuit110, which are then pressure-bonded to each other, so that the electrode pads131are electrically connected to the projecting electrodes118via conductive particles132A contained in the anisotropic conductive film132. As the electrode pads131of the substrate11are connected to the drive integrated circuit110in this manner, the drive circuit of the drive integrated circuit110is electrically connected to the third conductive structures130, and is further electrically connected from the third conductive structures130to the circuit forming the circuit layer12of the substrate11.

[4-2 Functions and Effects]

In the display element10according to the fourth embodiment, the area of the substrate11can be reduced, the stability of the connection between the substrate11and the drive integrated circuit110can be enhanced, and the stability of the connection between the drive integrated circuit110and the flexible substrate150can also be enhanced, as in the first embodiment. The number of channels between the drive integrated circuit110and the display element10can be increased, and the transmission rate can be made higher.

[5-1 Configuration of a Display Element]

As illustrated inFIG.7, a display element10according to a fifth embodiment includes conductive connecting members135that relay electrical connection with the outside.FIG.7is a cross-sectional view illustrating an example of the display element10according to the fifth embodiment. The display element10according to the fifth embodiment includes a drive integrated circuit110. The drive integrated circuit110has fourth conductive structures136as conductive structures that relay electrical connection with the drive circuit. The fourth conductive structures136of the drive integrated circuit110are electrically connected to the conductive connecting members135. Except for these aspects, the display element10according to the fifth embodiment is formed in a manner similar to that according to the first embodiment. Therefore, detailed explanation of other components, except for the conductive connecting members135, the fourth conductive structures136, and the structure of connection between the conductive connecting members135and the drive integrated circuit110, is not made herein. Note that, like the display element10according to the first embodiment, the display element10according to the fifth embodiment has a structure in which the drive integrated circuit110is disposed on one surface (on the light emitting surface D) of the substrate11.

The conductive connecting members135are conductive members that relay electrical connection with the outside. One end of each conductive connecting member135is located on the non-opposing surface110B not facing the substrate11among the surfaces of the drive integrated circuit110. The conductive connecting members135are members different from the flexible substrate150, and are wires135A in the example illustrated inFIG.7.FIG.7is an example, and does not prohibit any case where the conductive connecting members135differ from the wires135A. In the description of the fifth embodiment, however, a case where the conductive connecting members135are the wires135A is explained as an example.

In the example inFIG.7, each wire135A is electrically connected to an electrode pad of the drive integrated circuit on one end side thereof. The material of the wires135A is not limited to any particular material, and a metal material such as silver, gold, or copper can be used. The wires135A are normally connected to the respective electrode pads137, in accordance with the layout of the electrode pads.

The fourth conductive structures136that relay electrical connection with the conductive connecting members135are provided in the drive integrated circuit110. The fourth conductive structures136may be formed in a manner similar to that for the first conductive structures115formed in the display element10according to the first embodiment. The fourth conductive structures136are disposed in the drive integrated circuit110, and electrically connect the conductive connecting members135to the drive circuit. In the display element10according to the fifth embodiment, through holes136A are formed as the fourth conductive structures136, as illustrated inFIG.7. Each through hole136A has a structure that makes one end and the other end electrically continuous with each other in the thickness direction of the drive integrated circuit110. Each through hole136A may have the same structure as the through holes115A formed as the first conductive structures115.

In the fifth embodiment, like the electrode pads117of the first embodiment, the electrode pads137are formed on the non-opposing surface110B (the surface on the side opposite to the surface facing the light emitting surface D) of the drive integrated circuit110, and the electrode pads137are electrically connected to the through holes136A. The electrode pads137may be formed with a material similar to that of the electrode pads117. Further, the electrode pads137may be formed in a manner similar to that for the electrode pads117.

(Method of Connection between the Conductive Connecting Members and the Drive Integrated Circuit)

The method of electrical connection between the conductive connecting members135and the drive integrated circuit110is not limited to any particular method. However, in a case where the conductive connecting members135are the wires135A as illustrated inFIG.7, wire bonding can be adopted as an example of the method of electrical connection between the conductive connecting members135and the drive integrated circuit. In this case, one end portion of each wire135A is secured onto the corresponding electrode pad137by a wire bonding method. Note that, inFIG.7, reference numeral149indicates a bonding material for securing the wire135A to the electrode pad137. The portion fixed by the bonding material149is a connecting portion139A.

In the display element10according to the fifth embodiment, a sealing layer138is preferably provided as illustrated inFIG.7, for example. The sealing layer138covers the connecting portions139A between the conductive connecting members135and the drive integrated circuit110. In the example inFIG.7, the sealing layer138covers the connecting portions139A and the wires135A. The sealing layer138reduces breakage of the connecting portions139A and disconnection of the wires135A. The material of the sealing layer138may be a resin material or the like, for example.

[5-2 Functions and Effects]

With the display element10according to the fifth embodiment, effects similar to those of the first embodiment can be achieved.

A modification of the display element10according to the fifth embodiment is now described.

As illustrated inFIG.8, a display element10according to a modification of the fifth embodiment includes a first substrate140formed with the substrate11and a second substrate141different from the first substrate140, and the other end of each conductive connecting member135is electrically connected to the second substrate141.FIG.8is a cross-sectional view illustrating an example of the display element10according to the modification of the fifth embodiment.FIG.8also illustrates an example of the display element10in a case where the conductive connecting members135are the wires135A.

As illustrated inFIG.8, the second substrate141is a printed wiring board in which a circuit is formed in a base substrate141A. InFIG.8, as for the second substrate141, some of the wiring lines142forming the circuit are shown, and a view of the entire circuit is not shown. More specifically, the second substrate may be a so-called motherboard or the like, for example. The second substrate141is a substrate different from the flexible substrate150described above. The second substrate141may be a rigid substrate, for example. The second substrate141is bonded to the surface (second surface) of the first substrate140on the side opposite to the light emitting surface D. The method of bonding between the second substrate141and the first substrate140is not limited to any particular method, and may be a die bonding method or the like, for example.

(Method of Connection between the Conductive Connecting Members and the Second Substrate)

One end side of each conductive connecting member135is electrically connected to the drive integrated circuit110, and the other end side is electrically connected to the second substrate141. The method of electrical connection between the conductive connecting members135and second substrate141is not limited to any particular method. As illustrated inFIG.8, in a case where the conductive connecting members135are the wires135A, the wires135A and second substrate141may be electrically connected by a wire bonding method. In the example inFIG.8, conductive connecting terminals142A formed with wiring lines142formed in the circuit of the second substrate141are exposed through the side of the opposing surface (first surface side) facing the first substrate140among the surfaces of the second substrate141. The other end of each wire135A is then electrically connected to the corresponding connecting terminal142A of the second substrate141by a wire bonding method. Note that, as illustrated inFIG.8, in the display element10according to the modification of the fifth embodiment, both the connecting portions139A between the wires135A and the drive integrated circuit110, and connecting portions139B between the wires135A and the second substrate141are preferably sealed with the sealing layer138.

[6-1 Configuration of a Display Element]

In a display element10according to a sixth embodiment, as illustrated inFIG.9, conductive connecting members135are provided on the surface side (second surface side) opposite to a light emitting surface D among the surfaces of a substrate11.FIG.9is a cross-sectional view schematically illustrating an example of the display element10according to the sixth embodiment.

In the sixth embodiment, fifth conductive structures145, and electrode pads146connected to the fifth conductive structures145are disposed in the substrate11, and the conductive connecting members135are electrically connected to the fifth conductive structures145via the electrode pads146. In the example illustrated inFIG.9, the conductive connecting members135are connectors135B. Also, in this example, the fourth conductive structures136provided in the fifth embodiment, and the sealing layer138provided as appropriate are not shown. Except for these components, the display element10according to the sixth embodiment may be designed in a manner similar to that according to the fifth embodiment. Therefore, in the description of the sixth embodiment, explanation of the other components, except for the configuration of the conductive connecting members135, the fifth conductive structures145, and the electrode pads146, and the structure of connection between the conductive connecting members135and the fifth conductive structures145, is not made.

As described in the fifth embodiment, the conductive connecting members135are conductive connecting members that relay electrical connection with the outside. The conductive connecting members135are members different from the flexible substrate150, and are the connectors135B in the example illustrated inFIG.9.FIG.9is an example, and does not prohibit any case where the conductive connecting members135differ from the connectors135B. In the description of the sixth embodiment, however, explanation of an example case where the conductive connecting members135are the connectors135B is continued.

In the example inFIG.9, a connector135B includes a body147, and a wiring line148disposed on the outer peripheral surface of the body147. The material of the wiring line148is not limited to any particular material, and a metal material such as silver, gold, or copper can be used. The wiring line148continuously extends on the side surface of the substrate11from the side of the non-opposing surface (second surface side) not facing the substrate11among the surfaces of the body147, toward the side of the surface facing the substrate11. In the connector135B, an end portion of the wiring line148extending toward the side of the surface facing the substrate11is electrically connected to an electrode pad146of the substrate11. The shape of the body147of the connector135B is not limited, and is formed to have a trapezoidal cross-sectional shape in the example inFIG.9. Further, the material of the body147of the connector135B is preferably formed with an insulating material, and specifically, may be a resin material or the like, for example.

In the substrate11, the fifth conductive structures145are provided as conductive structures at the positions corresponding to the positions to which the connectors135B as an example of the conductive connecting members135are connected. The fifth conductive structures145may be the same structures as the second conductive structures125described in the third embodiment. The fifth conductive structures145may be formed with a material similar to and by a method similar to those for the second conductive structures125. Each fifth conductive structure145has a structure that makes one end and the other end electrically continuous with each other in the thickness direction of the substrate11. In the example inFIG.9, substrate through holes (referred to as third substrate through holes145A) having the same structure as the second conductive structures125are provided in the fifth conductive structures145. Note that, as illustrated inFIG.9, unlike the second conductive structures125, the fifth conductive structures145may be formed with holes (vias145B) that are electrically disconnected from the electrode pads21connected to the drive integrated circuit110, and have conductivity.

The electrode pads146are formed on the second surface side of the substrate11. The electrode pads146may be formed with a material similar to and by a method similar to those for the electrode pads126described in the third embodiment.

(Method of Connection between the Conductive Connecting Members and the Fifth Conductive Structures)

As the wiring lines148of the conductive connecting members135are connected to the electrode pads146, the wiring lines148are electrically connected to the fifth conductive structures145of the substrate11. The method of connection between the wiring lines148of the conductive connecting members135and the electrode pads146is not limited to any particular method. The method of connection between the wiring lines148of the conductive connecting members135and the electrode pads146may be a die bonding method or the like.

[6-2 Functions and Effects]

In the display element10according to the sixth embodiment, the area of the substrate11can be reduced, as in the first embodiment.

Also, in the display element10according to the sixth embodiment, the transmission distance for an electric signal from the conductive connecting members135such as the connectors135B to the integrated circuit of the drive integrated circuit110can be shortened, and the transmission rate can be made higher.

7 Example Applications

A display element10according to the present disclosure may be included in various electronic devices. For example, a display element (display element10) according to one of the embodiments (any one of the first to sixth embodiments) described above may be included in various electronic devices. Especially, a display element according to one of the above embodiments is preferably included in an electronic viewfinder of a video camera or a single-lens reflex camera, a head mounted display, or the like in which high resolution is required, used for enlarging near the eyes.

Specific Example 1

FIG.10Ais a front view illustrating an example of an external appearance of a digital still camera310.FIG.10Bis a rear view illustrating an example of an external appearance of the digital still camera310. The digital still camera310is of a lens interchangeable single-lens reflex type, and includes an interchangeable imaging lens unit (interchangeable lens)312substantially at the center on the front surface of a camera main body (camera body)311, and a grip313to be held by the photographer on the front left side.

A monitor314is provided at a position shifted to the left side from the center of the rear surface of the camera main body311. An electronic viewfinder (eyepiece window)315is provided above the monitor314. By looking through the electronic viewfinder315, the photographer can visually recognize an optical image of the subject guided from the imaging lens unit312, and determine a picture composition. As the electronic viewfinder315, a display element10according to any one of the above embodiments and modifications thereof can be used.

Specific Example 2

FIG.11is a perspective view illustrating an example of an external appearance of a head-mounted display320. The head-mounted display320includes ear hooking portions322to be worn on the head of the user on both sides of a display unit321in the shape of eyeglasses, for example. As the display unit321, a display element10according to any one of the above embodiments and modifications thereof can be used.

Specific Example 3

FIG.12is a perspective view illustrating an example of an external appearance of a television device330. The television device330includes a video display screen unit331including a front panel332and a filter glass333, and the video display screen unit331is formed with a display element10according to any one of the above embodiments and modifications thereof, for example.

The display elements according to the first to sixth embodiments of the present disclosure and the modifications of the embodiments, and the example applications have been specifically described so far. However, the present disclosure is not limited to the display elements according to the first to sixth embodiments and the modifications thereof, and the example applications described above, and various modifications based on the technical idea of the present disclosure can be made.

For example, the configurations, methods, steps, shapes, materials, numerical values, and the like given in the display elements according to the first to sixth embodiments and the modifications thereof, and the example applications are merely examples, and different configurations, methods, steps, shapes, materials, numerical values, and the like may be used as necessary.

The configurations, methods, steps, shapes, materials, numerical values, and the like of the display elements according to the first to sixth embodiments and the modifications thereof, and the example applications can be combined with one another without departing from the gist of the present disclosure.

The materials mentioned as examples in the display elements according to the first to sixth embodiments and the modifications thereof, and the example applications can be used independently of one another or in combination of two or more, unless otherwise specified.

Further, the present disclosure can also adopt the following configurations.(1) A display element including:a substrate that includes a light emitting element disposed therein, and has a light emitting surface;a drive integrated circuit including a drive circuit that controls driving of the light emitting element; anda flexible substrate having a connecting terminal, in which the drive integrated circuit is disposed on one surface of the substrate, andthe flexible substrate is disposed on a surface of the drive integrated circuit, the surface not facing the substrate.

(2) The display element of (1), in whicha first conductive structure that relays electrical connection with the drive circuit is disposed in the drive integrated circuit, andthe flexible substrate is electrically connected to the first conductive structure.

(3) The display element of (2), in whichthe first conductive structure includes a through hole that has conductivity and is electrically continuous in a thickness direction of the drive integrated circuit.

(4) The display element of (2), in whichthe first conductive structure includes a wiring line formed on a side surface of the drive integrated circuit.

(5) The display element of any one of (1) to (4), in whichthe drive integrated circuit is formed with a sub board on which the drive circuit is mounted.

(6) A display element including:a substrate that includes a light emitting element disposed therein, and has a light emitting surface;a drive integrated circuit including a drive circuit that controls driving of the light emitting element; anda flexible substrate,in which the drive integrated circuit is disposed on one surface of the substrate, andthe flexible substrate is disposed on a surface of the substrate, the surface being opposite to the light emitting surface.

(7) The display element of (6), in whicha second conductive structure that relays electrical connection with the drive integrated circuit is disposed in the substrate, andthe flexible substrate is electrically connected to the second conductive structure.

(8) The display element of (7), in whichthe second conductive structure includes a first substrate through hole that has conductivity and is electrically continuous in a thickness direction of the substrate.

(9) The display element of any one of (6) to (8), in whicha counter substrate that covers the light emitting surface of the substrate is provided, andthe drive integrated circuit is disposed on a side of the light emitting surface of the substrate, anda position of a surface not facing the substrate among surfaces of the drive integrated circuit is aligned with a position of an exposed surface of the counter substrate.

(10) The display element of any one of (6) to (8), in whichthe drive integrated circuit is disposed on a surface of the substrate, the surface being opposite to the light emitting surface.

(11) The display element of (10), in whichthe substrate includes a circuit,a third conductive structure that relays electrical connection with the circuit is disposed in the substrate, andthe drive integrated circuit is electrically connected to the third conductive structure.

(12) The display element of (11), in whichthe third conductive structure includes a second substrate through hole that has conductivity and is electrically continuous in a thickness direction of the substrate.

(13) A display element including:a substrate that includes a light emitting element disposed therein, and has a light emitting surface;a drive integrated circuit including a drive circuit that controls driving of the light emitting element; anda conductive connecting member that relays electrical connection with outside,in which the drive integrated circuit is disposed on one surface of the substrate, andthe conductive connecting member is disposed on a surface of the drive integrated circuit, the surface not facing the substrate.

(14) The display element of (13), in whicha fourth conductive structure that relays electrical connection with the drive circuit is disposed in the drive integrated circuit, andthe conductive connecting member is electrically connected to the fourth conductive structure.

(15) The display element of (14), in whichthe fourth conductive structure includes a through hole that has conductivity and is electrically continuous in a thickness direction of the drive integrated circuit.

(16) The display element of any one of (13) to (15), in whichthe conductive connecting member includes a wire.

(17) The display element of any one of (13) to (16), including:a first substrate formed with the substrate; anda second substrate that is different from the first substrate, and is disposed on a side of a surface opposite to the side of the light emitting surface with respect to the first substrate,in which one end of the conductive connecting member is electrically connected to the drive integrated circuit, and the other end of the conductive connecting member is electrically connected to the second substrate.

(18) A display element including:a substrate that includes a light emitting element disposed therein;a drive integrated circuit including a drive circuit that controls driving of the light emitting element; anda conductive connecting member that relays electrical connection with outside,in which the drive integrated circuit is disposed on one surface of the substrate, andthe conductive connecting member is disposed on a side of a surface of the substrate, the surface being opposite to a light emitting surface.

(19) The display element of (18), in whicha fifth conductive structure that relays electrical connection with the drive integrated circuit is disposed in the substrate, andthe conductive connecting member is electrically connected to the fifth conductive structure.

(20) The display element of (19), in whichthe fifth conductive structure includes a substrate through hole that has conductivity and is electrically continuous in a thickness direction of the substrate.

(21) The display element of any one of (18) to (20), in whichthe conductive connecting member is a connector.

(22) An electronic device includingthe display element of any one of (1) to (21).

REFERENCE SIGNS LIST