JP2004362788A - Organic EL display device and manufacturing method thereof - Google Patents

Abstract

The present invention provides an organic EL display device which facilitates wiring connection, can be reduced in cost, has a narrow frame, and can be made thinner, and a method of manufacturing the same.
Kind Code: A1 An organic EL display body in which a protective film for protecting an organic EL structure is applied to the entire surface of a substrate opposite to a display side, and a wiring support substrate on which driving semiconductor elements are mounted. 2, the wirings 13 and 14 connected to the electrodes 112 and 114 of the organic EL structure 11 are formed on the protective film 12, and the wiring and the wiring support substrate respectively serve as the driving semiconductor element. It has connection electrode portions 15 and 26 for connection, and these connection electrode portions are electrically connected to each other through elastic connection means 3.
[Selection diagram] FIG.

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an organic electroluminescence (hereinafter, referred to as organic EL) display device and a method for manufacturing the same.
[0002]
[Prior art]
The organic EL display is a display utilizing an electroluminescence phenomenon in which the luminous body emits light when an electric field is applied to the luminous body made of an organic compound. Organic EL is a self-luminous type and has many features such as high brightness, high viewing angle, high-speed response, light weight, and thin shape, and has been actively researched and developed in recent years. The results have emerged as a number of proposals.
Among them, Patent Literatures 1 and 2 disclose a wiring structure for connecting a driving circuit of an organic EL.
[0003]
[Patent Document 1]
JP-A-2000-223267 (paragraphs [0040] to [0048], FIGS. 1 to 3)
[Patent Document 2]
JP-A-2000-3140 (paragraphs [0014]-[0017], FIGS. 1 and 6)
[0004]
Patent Literature 1 discloses that an organic EL driving circuit is disposed inside a sealing member (cap), and wiring for connecting to the driving circuit is provided from the inside of the sealing member to the back side of the organic EL display body (that is, sealing). It discloses a wiring structure that is led out to the front side of a member). Therefore, a mounting hole for a connector is provided in the sealing member, and the drive circuit inside the sealing member is connected to an external substrate on which the IC is mounted via the connector.
Patent Literature 2 discloses that a part of a driving circuit of an organic EL is formed on a sealing member (cap), and a wiring structure for connecting a part of the driving circuit and another driving circuit is formed around the sealing member. Discloses a wiring structure arranged on a substrate.
[0005]
[Problems to be solved by the invention]
The above prior art has the following problems.
In the wiring structure of Patent Document 1, the organic EL drive circuit and the connector must be connected by wiring, and the connection with the connector requires a smaller wiring pitch. There is a problem. The large number of wiring connection steps also contributes to high cost and reduced reliability.
In addition, the connector must have at least an airtight structure, and furthermore, it is necessary to ensure sufficient sealing with a mounting hole provided in the cap. Therefore, the operation of attaching the connector is complicated and the cost is inevitably increased.
On the other hand, in the wiring structure of Patent Document 2, a special wiring structure is provided to connect a drive circuit of the organic EL and a wiring on a sealing member (cap). It is necessary to make it for every body size, and there is a problem that the cost is high.
[0006]
SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems of the related art, and an organic EL display device which facilitates wiring connection, can be reduced in cost, has a narrow frame wiring, and can be made thinner, and its manufacture. It is intended to provide a way.
[0007]
[Means for Solving the Problems]
The organic EL display device according to the present invention includes an organic EL display body in which a protective film for protecting the organic EL structure is applied to the entire surface of the substrate on the side opposite to the display side, and a wiring support substrate on which a driving semiconductor element is mounted. A wiring connected to the electrode of the organic EL structure is formed on the protective film, and the wiring and the wiring support substrate each have a connection electrode portion for connecting the driving semiconductor element. The connection electrodes are electrically connected to each other via elastic connection means.
[0008]
The organic EL display device of the present invention is one in which the organic EL display is electrically connected to the wiring supporting substrate on which the driving semiconductor element is mounted via elastic connection means. On the organic EL display, a protective film for protecting the organic EL structure is applied to the entire surface of the substrate opposite to the display side, and wiring for connecting to the electrodes of the organic EL structure is formed on the protective film. Therefore, the wiring pattern width can be widened, the degree of freedom in wiring pattern arrangement is high, such as the freedom of pitch conversion, and the connection with the driving semiconductor element on the wiring support substrate can be easily performed. In both cases, since the contact area of the connection electrode portion can be increased, the reliability of connection with the driving semiconductor element can be improved. Further, since the connection means for connecting the electrode of the organic EL structure and the wiring on the protective film can be arranged at the edge of the substrate, the wiring with a narrow frame can be provided. Furthermore, since the organic EL display device of the present invention has a simple wiring structure, it can be reduced in cost and thickness.
[0009]
Further, in the organic EL display device of the present invention, a holder member is engaged with a side end of the organic EL display and the wiring support substrate.
With this holder member, the connection state of the connection electrode portion by the elastic connection means can be stably held.
As the elastic connection means, it is suitable to use a conductive ball, a conductive elastic body, or a conductive rubber sheet or an anisotropic conductive sheet.
[0010]
The method for manufacturing an organic EL display device according to the present invention includes a wiring step for an organic EL display, a wiring step for a wiring support substrate, and a connecting step for connecting the organic EL display and the wiring support substrate after wiring.
The wiring step of the organic EL display body includes a step of applying a protective film for protecting the organic EL structure over the entire surface of the substrate opposite to the display side, and a step of forming a wiring having a connection electrode portion on the protective film. Forming, and forming a connection means for electrically connecting the electrode of the organic EL structure and the wiring, respectively,
The wiring step of the wiring support substrate includes a step of connecting a driving semiconductor element on a wiring support substrate having a connection electrode portion on the back surface,
The step of connecting the organic EL display body after the wiring and the wiring support substrate includes a step of electrically connecting a connection electrode portion on the protective film and a connection electrode portion on the back surface of the wiring support substrate via elastic connection means. It is characterized by having.
With this configuration, the narrow frame, thin organic EL display device of the present invention can be manufactured at low cost.
[0011]
In the step of forming the connection means, a connection hole reaching the electrode of the organic EL structure is formed in the protective film, and connection is made by filling the inside of the connection hole with a conductor.
The conductor is, for example, a conductive paste discharged by an ink-jet method, and the first and second connection means are formed by filling the connection holes with the conductive paste. Therefore, connection of the first and second wirings for connection to the drive circuit of the organic EL structure can be easily and accurately performed. Further, since the connection holes are sealed with a conductor, there is no problem of contamination by outside air.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. It goes without saying that the present invention is not limited to the illustrated example.
Embodiment 1 FIG.
1 is a perspective view showing an outline of an organic EL display device according to a first embodiment of the present invention, FIG. 2 is a schematic plan view of the organic EL body of FIG. 1, and FIG. 3 is an enlarged cross-sectional view taken along line AA of FIG. 4 is an enlarged sectional view taken along line BB of FIG. 2, and FIG. 5 is a sectional view showing an assembled state of the organic EL display device.
The organic EL display device 10 includes an organic EL display 1 constituting a main body of the device, and a wiring support substrate 2 which is in contact with the organic EL display 1 to perform electrical connection. On the wiring support substrate 2, first and second driving semiconductor elements 21 and 22 composed of a driving IC and the like of the organic EL display 1 are mounted, and are connected to an external substrate (not shown). The wiring 25 is formed.
[0013]
The organic EL display 1 includes an organic EL structure (organic EL element) 11 and an insulating material applied to the entire back surface of the organic EL structure 11 (the surface opposite to the display side and the upper surface in FIG. 1). Protective film 12, and an anode wiring 13 and a cathode wiring 14 formed on the protection film 12 and electrically connected to the internal wiring of the organic EL structure 11. The wiring 13 for the anode and the wiring 14 for the cathode are connected to the connection electrode portions 24 of the first and second driving semiconductor elements 21 and 22 formed on the wiring support substrate 2 via the respective elastic connection means 3. The connection electrode part 15 is formed. In this example, the connection electrode portion 15 is disposed at a position substantially facing the terminal portion 23 or the connection electrode portion 24 of the first and second driving semiconductor elements 21 and 22. The anode wiring 13 and the cathode wiring 14 are connected to the respective anode (first electrode) 112 and cathode (second electrode) 114 constituting the internal wiring by first and second connection means 16. , 17 are connected. The positions of the first and second connection means 16 and 17 are not particularly limited, but it is preferable that at least one of the connection means is arranged at the edge of the substrate. Thus, the organic EL display 1 having a narrow frame can be manufactured.
[0014]
A connection electrode portion 24 connected to the terminal portion 23 of the first and second driving semiconductor elements 21 and 22 is formed on the wiring support substrate 2 so as to penetrate the wiring support substrate 2. Further, an electrode terminal 26 to which an external substrate (not shown) such as a flexible substrate is connected is formed on the wiring 25 on the wiring support substrate 2. As the wiring support substrate 2, a general printed wiring board may be used. A hard substrate such as an epoxy resin containing glass fiber is suitable.
[0015]
Then, as shown in FIG. 5, the organic EL display 1 and the wiring support substrate 2 are connected via the elastic connection means 3 composed of, for example, conductive balls 31. The conductive sphere 31 is formed by forming a metal film on a surface layer of a resin sphere, and is electrically connected between wiring conductors by being deformed under pressure. The conductive spheres 31 are adhered and arranged on the connection electrode portions 15 of the anode wiring 13 and the cathode wiring 14 with, for example, a conductive paste, and are connected by pressing the wiring support substrate 2 from above. In order to stably maintain the elastic connection state of the conductive spheres 31, a U-shaped or channel-shaped holder member 4 is engaged with both side end portions of the organic EL display 1 and the wiring support substrate 2. ing.
[0016]
The main configuration of the organic EL structure 11 includes a transparent substrate 111 made of glass, synthetic resin, or the like, and a plurality of striped anodes (first electrodes) arranged on the substrate 111 at predetermined intervals in a column direction. A plurality of striped cathodes (second electrodes) arranged in parallel in the row direction at predetermined intervals with the light emitting layer 113 interposed between the anode 112 and the light emitting layer 113 disposed on the anode 112; Electrode 114 and the anode 112 and between the light emitting layers 113, the cathode 114 is disposed on the upper surface thereof, and an insulating material acting as a sealing material for preventing invasion of outside air. And a layer 115.
[0017]
The anode 112 is formed of a transparent electrode, for example, an ITO (Indium Tin Oxide) thin-film electrode because it is necessary to transmit light here. Cathode 114 arranged in a matrix with respect to anode 112 is made of a metal electrode such as aluminum. The light emitting layer 113 sandwiched between the anode 112 and the cathode 114 arranged in a matrix may be a single layer made of one or more kinds of organic materials, or a hole injection layer, a hole transport layer, an electron transport layer, Any of a multilayer structure including a plurality of layers including an electron injection layer and the like may be used. For example, depending on the use, performance, cost, etc. of the organic EL display, (a) anode-light-emitting layer-cathode, (b) anode-hole injection layer-light-emitting layer-cathode, (c) anode-light-emitting layer- An appropriate combination may be selected from electron injection layer-cathode, (d) anode-hole injection layer-light-emitting layer-electron injection layer-cathode, and the like.
The light emitting layer 113 forms one pixel at each intersection of the anode 112 and the cathode 114, and emits light by applying an electric field between the anode 112 and the cathode 114. When the anode 112 is a data line electrode and the cathode 114 is a scanning line electrode, by transmitting a desired image data signal to the anode 112 and a scanning signal to the cathode 114, characters, images, and the like can be displayed. it can.
Further, by arranging the light-emitting layers 113 in a dot matrix that emits three colors of red (R), green (G), and blue (B), a so-called full-color display is possible.
[0018]
Here, the insulating layer 115 is formed of a material (for example, epoxy resin, SiO _2, or the like) having electrical insulation and airtightness (gas impermeable), and is coated so as to surround the anode 112 and the light emitting layer 113. ing. Further, a sealing cap may be attached so as to surround the insulating layer 115 in order to improve airtightness.
Note that the present invention is applicable to both the passive type and the active type of the organic EL display 1. In the case of the active system, a TFT (thin film transistor) provided for each pixel is disposed on the substrate 111.
[0019]
6 to 10 are schematic process diagrams for explaining a wiring method or a manufacturing method of the organic EL display 1. Hereinafter, the wiring method of the organic EL display 1 will be described with reference to these process schematic diagrams.
[0020]
A. Step of applying protective film (see FIG. 6)
First, as shown in FIG. 6, in order to protect the organic EL structure 11, a protective film 12 made of an insulating film is disposed (deposited) on the entire substrate on the back surface of the organic EL structure 11. The protective film 12 may be any material that can suppress or prevent the deterioration of the organic EL structure 11 by, for example, depositing SiO ₂ or SiN. The protective film 12 is disposed on the entire surface of the substrate including the internal electrode terminals 116 and 117 of the anode 112 and the cathode 114, thereby protecting the organic EL structure 11 and facilitating the steps described later. . As such a protective film 12, for example, a gas impermeable film, a resin coating film, or glass is used in addition to the above-described vapor-deposited film. Further, the protective film 12 may be formed by a sputtering method, a spin coating method, or the like.
[0021]
B. Wiring forming process (see FIG. 7)
Next, as shown in FIG. 7, an anode wiring 13 and a cathode wiring 14 are formed on the protective film 12 in a required wiring pattern. For example, an etching method, a printing method, an electroless plating method, an electrolytic plating method, or an ink jet method for discharging a conductive adhesive can be used to create a wiring pattern. It is desirable to use metal wiring such as copper in order to keep the temperature low. Further, it is preferable to determine the pattern area or the conductor volume in order to keep the resistance value of each wiring constant.
At the time of this wiring processing, connection electrode portions 15 for connecting to the first and second driving semiconductor elements 21 and 22, respectively, are formed at one end of each of the wirings 13 and 14. The connection electrode portion 15 is disposed on the wiring support substrate 2 at a position substantially corresponding to the connection electrode portion 24 of the first and second driving semiconductor elements 21 and 22.
[0022]
C. Connection hole processing (see Fig. 8)
Next, as shown in FIGS. 8, 12, and 13, on the protective film 12 near the wirings 13 and 14 (for example, within 500 μm from one end of the wiring), the anode and the cathode are pierced through the protective film 12. A connection hole 118 reaching each of the electrode terminals 116 and 117 is provided. 12 and 13 are a perspective view and a sectional view showing a certain connecting means 16 in an enlarged manner.
The connection hole 118 can be processed by etching, laser, electron beam, or the like. Further, the connection holes 118 may be directly formed on the conductor ends of the wirings 13 and 14.
[0023]
D. Wiring connection process (see Fig. 9)
After the processing of the connection hole 118, as shown in FIGS. 9, 12, and 13, the conductive paste 119 is accurately spotted inside and near the connection hole 118 by, for example, an ink jet method to form the wirings 13 and 14. Each one end portion (an electrode terminal portion may be formed) is electrically connected to each of the electrode terminal portions 116 and 117 of the anode 112 and the cathode 114, respectively. As a result, the wiring 13 and the anode 112 and the wiring 14 and the cathode 114 are connected to be in an electrically conductive state. Further, since the inside of the connection hole 118 is filled with a conductor such as the conductive paste 119, outside air does not enter the connection hole 118.
The connection means 16 and 17 shown in FIGS. 1 to 5 are, for example, the connection holes 118 and the conductive paste 119 or the like which is dropped inside and near the holes 118 to conduct the internal wiring and the wirings 13 and 14. It is an electrical connection means made of a conductive adhesive. The connection means 16 and 17 are not limited to the parallel arrangement but may be a staggered arrangement.
In addition, as the connection means, in addition to the above-described ink jet method, connection may be performed by electroless plating, thermal spraying of metal, solder, or the like, using an appropriate pattern and mask only at the connection portion.
As described above, the organic EL display 1 having the wiring structure shown in FIGS. 1 to 5 can be manufactured.
[0024]
E. FIG. Wiring process of wiring support substrate (see FIGS. 10 and 11)
The wiring (manufacturing) of the wiring support substrate 2 is performed separately from the organic EL display 1 described above. FIG. 10 is a top view of the wiring support substrate, and FIG. 11 is a cross-sectional view. Since a printed wiring board is generally used, the connection of the first and second driving semiconductor elements 21 and 22 is mainly performed here.
Wiring 25 and connection holes 27 formed by through-hole plating or the like are arranged at appropriate positions on the wiring support substrate 2, and connection electrode portions 24 that conduct to the connection holes 27 are formed on the back surface of the wiring support substrate 2. I have. Similarly to the connection electrode portion 15 on the protective film 12, the connection electrode portion 24 can be freely arranged with a wider pitch and area than the terminal interval between the driving semiconductor elements 21 and 22.
Then, the first driving semiconductor element 21 of the anode driver and the second driving semiconductor element 22 of the cathode driver are connected to the wiring 25 on the wiring supporting substrate 2 by conductive paste or soldering.
[0025]
In this way, the wiring connection of the wiring support substrate 2 is performed. Then, as described above, the organic EL display 1 and the wiring support substrate 2 on which the wiring is made are connected as shown in FIG. 5 using the conductive balls 31 and the holder member 4.
The connection method (mounting method) of the driving semiconductor elements 21 and 22 is not limited to flip chip mounting of bare chips, but may be wire bonding or soldering, or a normal method such as conductive paste or anisotropic conductive film. It is not limited.
In addition, the driving semiconductor elements 21 and 22 may use a package in the form of TCP (Tape Carrier Package), COF (Chip On Film), or resin-sealed SOP (Small Outline Package).
[0026]
Thus, the organic EL display device 10 having the wiring structure shown in FIGS. 1 to 5 can be manufactured. Then, the electrode terminal portions 26 on the wiring support substrate 2 and an external substrate (not shown) such as a flexible substrate are electrically connected by ordinary soldering, a conductive paste, an anisotropic conductive film, a connector, or the like. Further, one driving semiconductor element may be mounted on an external substrate.
[0027]
Since the organic EL display device 10 is configured as described above, the entire surface of the substrate of the organic EL structure 11 is sufficiently protected by the protective film 12, and then the internal organic EL driving circuit is mounted on the protective film 12. Wiring circuits (13 to 17) for driving can be provided. Therefore, the space for forming the wiring circuits (13 to 17) can be made sufficiently large, and the wiring pattern can be formed at an arbitrary connection pitch. The electrode area can be freely designed. Therefore, the connection reliability when the connection electrode portion 15 on the protective film 12 and the connection electrode portion 24 on the back surface of the wiring support substrate 2 are connected via the elastic connection means 3 can be improved, and the driving semiconductor element can be improved. 21 and 22 are very easy to mount. Further, since at least one of the connection means 16 and 17 for connecting the wirings 13 and 14 to the anode 112 and the cathode 114 is arranged at the edge of the substrate, the organic EL display device 10 having a narrow frame can be easily realized. Can be. Further, since the wiring structure is simple, the cost can be reduced and the thickness can be reduced.
Further, since the organic EL display 1 and the wiring support substrate 2 are manufactured separately, it is possible to suppress the occurrence of defects in the organic EL display 1 and to manufacture the wiring support substrate 2 with a high degree of freedom in the wiring pattern. Since it becomes easy, disconnection and malfunction are suppressed, and the yield is improved.
[0028]
Embodiment 2 FIG.
FIG. 14 is a top view of the organic EL display 1 according to the second embodiment of the present invention, and FIG. 15 is a bottom view of the wiring support substrate 2.
As shown in FIG. 14, the connection electrodes 15 on the protective film 12 can be freely designed in arrangement, interval, and electrode area. Then, the connection electrode portion 24 is arranged on the back surface of the wiring support substrate 2 in a pattern facing the connection electrode portion 15.
According to such an arrangement configuration of the connection electrode portions 15 and 24, the contact area can be increased, so that the connection reliability is further improved.
[0029]
Embodiment 3 FIG.
16 and 17 are sectional views of an organic EL display device according to another embodiment of the present invention.
FIG. 16 shows the connection electrode portion 15 of the organic EL display 1 and the wiring support substrate 2 using an elastic body 32 such as a conductive metal spring terminal or a spring terminal in which the surface of a resin leaf spring is coated with a metal such as gold plating. FIG. 17 shows an example in which the connection electrode portion 15 of the organic EL display 1 is connected to the connection electrode portion 24 of the wiring support substrate 2 using a conductive rubber sheet 33. It is. The conductive rubber sheet 33 conducts electrical conduction by pressurization, but may be an anisotropic conductive sheet in which only the pressing portions 34 scattered as shown in FIG. 18 have conductivity.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view of an organic EL display device according to a first embodiment of the present invention.
FIG. 2 is a schematic plan view of the organic EL display of FIG.
FIG. 3 is an enlarged sectional view taken along line AA of FIG. 2;
FIG. 4 is an enlarged sectional view taken along line BB of FIG. 2;
FIG. 5 is a sectional view of an assembled state of the organic EL display device.
FIG. 6 is a process schematic diagram showing a wiring method of the organic EL display.
FIG. 7 is a process schematic diagram following FIG. 6;
FIG. 8 is a process schematic diagram following FIG. 7;
FIG. 9 is a schematic view of the process following FIG. 8;
FIG. 10 is a schematic top view showing a wiring method of a wiring support substrate.
FIG. 11 is a sectional view of FIG. 10;
FIG. 12 is a perspective view of a connection unit.
FIG. 13 is a sectional view of FIG.
FIG. 14 is a top view of the organic EL display according to the second embodiment of the present invention.
FIG. 15 is a bottom view of the wiring support substrate according to the second embodiment.
FIG. 16 is a sectional view of an organic EL display device according to a third embodiment of the present invention.
FIG. 17 is a sectional view of an organic EL display device according to another embodiment of the present invention.
FIG. 18 is a plan view of a conductive rubber sheet.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 organic EL display, 2 wiring support substrate, 3 elastic connecting means, 4 holder member, 10 organic EL display, 11 organic EL structure, 12 protective film, 13 anode wiring, 14 cathode wiring, 15 connection electrode section , 16 first connecting means, 17 second connecting means, 21 first driving semiconductor element, 22 second driving semiconductor element, 23 terminal section, 24 connecting electrode section, 25 wiring, 26 electrode terminal section, 27 connection hole, 31 conductive ball, 32 elastic body, 33 conductive rubber sheet, 111 substrate, 112 anode, 113 light emitting layer, 114 cathode, 115 insulating layer, 116, 117 electrode terminal part, 118 connection hole, 119 conductive paste

Claims (5)

An organic EL display body in which a protective film for protecting the organic EL structure is applied to the entire surface of the substrate on the side opposite to the display side; and a wiring support substrate on which a driving semiconductor element is mounted. Wiring connected to the electrode of the organic EL structure is formed, and the wiring and the wiring support substrate each have a connection electrode portion for connecting the driving semiconductor element, and the connection electrode portions are elastically connected to each other. An organic EL display device electrically connected via means. 2. The organic EL display device according to claim 1, wherein a holder member is engaged with a side end portion of the organic EL display body and the wiring support substrate. 3. The organic EL display device according to claim 1, wherein any one of a conductive sphere, a conductive elastic body, a conductive rubber sheet, and an anisotropic conductive sheet is used as the elastic connection means. A wiring process of the organic EL display, a wiring process of the wiring support substrate, and a connection process of the organic EL display and the wiring support substrate after wiring,
The wiring step of the organic EL display body includes a step of applying a protective film for protecting the organic EL structure over the entire surface of the substrate opposite to the display side, and a step of forming a wiring having a connection electrode portion on the protective film. Forming, and forming a connection means for electrically connecting the electrode of the organic EL structure and the wiring, respectively,
The wiring step of the wiring support substrate includes a step of connecting a driving semiconductor element on a wiring support substrate having a connection electrode portion on the back surface,
The step of connecting the organic EL display body after the wiring and the wiring support substrate includes a step of electrically connecting a connection electrode portion on the protective film and a connection electrode portion on the back surface of the wiring support substrate via elastic connection means. A method for manufacturing an organic EL display device, comprising: 5. The connection step according to claim 4, wherein, in the step of forming the connection means, a connection hole reaching the electrode of the organic EL structure is formed in the protective film, and the connection is made by filling the inside of the connection hole with a conductor. Method for manufacturing an organic EL display device.

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