JP2006040801A - Organic el panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL panel in which connection reliability on a connecting member is enhanced. <P>SOLUTION: The organic EL panel is provided with: an organic EL element 2 which is arranged on a translucent plate board 21, and composed of an organic layer 25 including at least a luminescent layer that is nipped and held by a translucent anode line 22a and a non-translucent second electrode 26; a first electrode terminal 22d which is installed on the translucent plate board 21 and electrically connected to the anode line 22a and the second electrode 26; and a connecting member 4 equipped with a second electrode terminal 41b that is electrically connected to a first electrode terminal 22d. On the first electrode terminal 22d, a low resistance layer 22e having a smaller resistivity than that of the anode line 22a is formed so as to expose a part of the first electrode terminal 22d. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an organic EL panel in which an organic EL element in which an organic layer having at least a light emitting layer is sandwiched between a transparent electrode and a back electrode is disposed on a translucent substrate, and in particular, connected to the organic EL panel. The present invention relates to a connection structure with a member.

  Conventionally, as an organic EL panel, for example, a transparent electrode serving as an anode made of ITO (indium tin oxide) or the like, a hole injection layer, a hole transport layer, a light emitting layer, and an electron transport on a translucent substrate made of a glass material. An organic layer composed of layers and a non-translucent back electrode such as aluminum (Al) serving as a cathode are sequentially laminated to form an organic EL element which is a laminate, and the organic EL element is hermetically covered with glass. A sealing member made of a material is disposed on the light-transmitting substrate.

For connection with other devices (for example, a display control controller or a constant current source circuit) in the organic EL panel, for example, a connection member made of a flexible flexible substrate is used. For example, on one side of the glass substrate, lead portions each formed by being drawn out from the transparent electrode and the back electrode are concentratedly arranged, and a tip portion of the lead portion is electrically connected to the flexible substrate. Electrode terminals are formed. A low resistance layer made of chromium or the like having a resistance smaller than that of ITO is laminated on the electrode terminal in order to allow a constant current to flow through the light emitting portion satisfactorily. As a means for forming such a low resistance layer, for example, after patterning a transparent electrode on a translucent substrate, a low resistance film made of chromium is laminated on the entire surface, and a region where the low resistance layer is to be formed is covered with a resist, A means for selectively etching the low resistance film is employed. On the other hand, a predetermined circuit wiring is formed on the flexible substrate side, and a connection terminal electrically connected to the low resistance layer formed on the electrode terminal is provided at the end of the circuit wiring. An anisotropic conductive film (anisotropic conductive film) is used for electrical connection of the terminal groups between the organic EL panel and the flexible substrate (see, for example, Patent Document 1 below).
JP 2000-3793 A

  In the case of the organic EL panel described in Patent Document 1, after forming a transparent electrode on a translucent substrate, a low resistance layer is formed on the electrode terminal of the transparent electrode, and further an organic layer is formed on the transparent electrode It is the structure to do. By the way, in the process from the formation of the low resistance layer to the formation of the organic layer, the surface of the transparent electrode and the low resistance layer is smoothed, and foreign matter such as dust attached on the light transmitting substrate. In order to remove the transparent substrate, it is necessary to polish the surface of the translucent substrate on which the transparent electrode and the low resistance layer are formed, and then clean the translucent substrate.

However, the surface of the low-resistance layer made of chromium is oxidized by being exposed to the air when the translucent substrate is transported from the polishing process to the cleaning process, and thereby the entire surface of the low-resistance layer is oxidized. In some cases, an oxide film made of chromium oxide is formed. When the low resistance layer on which the oxide film is formed and the connection terminal of the flexible substrate as a connecting member are electrically connected via an anisotropic conductive film, the anisotropy film causes the anisotropy to occur. Since the adhesion between the conductive particles in the conductive film and the low resistance layer is lowered, there is a possibility that the conductive connection between the organic EL panel and the flexible substrate may be hindered, and there is room for improvement in terms of connection reliability. It was left.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an organic EL panel capable of improving connection reliability with respect to a connection member in order to cope with the above-described problems.

  The present invention provides an organic EL element disposed on a translucent substrate and sandwiching at least an organic layer including a light emitting layer between a transparent electrode and a back electrode, and electrically connected to the transparent electrode and the back electrode A first electrode terminal provided on the translucent substrate; and a connecting member including a second electrode terminal electrically connected to the first electrode terminal, the first electrode terminal being provided on the first electrode terminal. A low-resistance layer having a lower resistivity than the transparent electrode is formed so as to expose at least a part of the first electrode terminal.

  Further, the present invention is characterized in that the first electrode terminal and the second electrode terminal are electrically connected through an anisotropic conductive film or heat seal.

  In the invention, it is preferable that the connecting member is a flexible substrate having flexibility.

  In the invention, it is preferable that the first electrode terminal is made of ITO, and the low resistance layer is formed in a comb shape with respect to the ITO.

  ADVANTAGE OF THE INVENTION According to this invention, the organic EL panel which can achieve an initial objective and can improve the connection reliability with respect to a connection member can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings, taking a display device including an organic EL panel as an example.

  In FIG. 1, the display device includes a front frame 1, an organic EL panel 2 disposed behind the front frame 1, and a driving unit for driving the organic EL panel 2 disposed behind the organic EL panel 2. It is comprised from the board | substrate (circuit board | substrate) 3, and the connection member 4 which intervenes between the organic EL panel 2 and the drive board | substrate 3, and carries out the conductive connection.

  The front frame 1 is formed by pressing a plate made of a metal material into a box shape, and is a housing member that houses the organic EL panel 2, the driving substrate 3, and the connection member 4. 5, and a caulking portion 1 c having a plurality of caulking pieces 1 b formed in the lower end of each side surface and extending in a substantially “L” shape on the side of the driving substrate 3.

  As shown in FIGS. 2 to 4, the organic EL panel 2 includes a translucent substrate 21, a first electrode 22, an insulating layer 23, ribs (partition walls) 24, an organic layer 25, and a back surface made of a metal film. An electrode (second electrode) 26 and a sealing member 27 are provided.

  The translucent substrate 21 is made of a rectangular transparent glass material and is an electrically insulating substrate.

  The first electrode 22 is formed of, for example, a light-transmitting conductive material made of ITO and a metal conductive material made of chromium or the like. The first electrode 22 is made of ITO on the light-transmitting substrate 21 by means such as vapor deposition or sputtering. After sequentially forming the electrode film and the chromium metal film, the ITO and the chromium are removed by etching except for the anode line and the first electrode terminal described later (first etching step). This is obtained by etching away the chromium except for a portion to be a low resistance layer, which will be described later, partially formed on the first electrode terminal portion exposed from the sealing member 27 (second). Etching process).

  That is, the first electrode 22 includes a plurality of anode lines (transparent electrodes) 22a formed in a row at predetermined intervals with respect to the longitudinal direction of the light emitting display portion 5 in the light emitting display portion 5 by the first etching step. In the longitudinal direction of the light-emitting display portion 5, the first electrode terminal 22d including the electrode line 22b continuously drawn to the second electrode 26 group and the electrode line 22c continuously drawn to the anode line 22a group is provided. In this case, the electrode lines 22 b are concentrated and arranged on the left side of the light emitting display unit 5, and the electrode lines 22 c are concentrated and arranged below the light emitting display unit 5.

  Furthermore, on each first electrode terminal 22d portion exposed from the sealing member 27 in each first electrode terminal 22d, a low resistivity made of chromium, which has a lower resistivity than the ITO by the second etching step. The resistance layer 22e is laminated so as to partially expose the first electrode terminal 22d (see FIG. 5). In this case, each low-resistance layer 22e is formed on each first electrode terminal 22d so as to have a comb-tooth shape, and each first electrode is formed through the comb-shaped non-formation region (extracted portion). A part of the terminal 22d is exposed (see FIG. 6).

  The insulating layer 23 is made of, for example, a polyimide-based electrically insulating material, and is formed on the anode line 22a so as to be positioned between the anode line 22a and the second electrode 26, thereby preventing a short circuit between the electrodes 22a and 26. In addition, the outline of the organic EL element 7 (dot location) which is the light emitting portion 6 is clarified.

  The rib 24 is made of, for example, a phenol-based electrically insulating material, and is formed on the insulating layer 23. The rib 24 is formed by means such as a photolithography method so that the cross section thereof has an overhang shape such as an inverted trapezoidal shape. A plurality of ribs 24 are formed at equal intervals in a direction orthogonal to the anode line 22a. The rib 24 has a structure in which the organic layer 25 and the metal film are cut off due to an overhang shape when a metal film to be the organic layer 25 and the second electrode 26 is formed from above by a vapor deposition method, a sputtering method, or the like. Is.

  The organic layer 25 is formed by sequentially laminating a hole injection layer, a hole transport layer, a light emitting layer, and an electron transport layer on the anode line 22a by means of vapor deposition or sputtering. The organic layer 25 is formed on the anode line 22 a and the rib 24, but there is a layer that is cut off by the rib 24 and laminated on the upper surface of the rib 24.

  The second electrode 26 is obtained by using a metallic conductive material such as aluminum (AL) or magnesium silver (Mg: Ag) and forming these materials in a line shape by means such as sputtering or vapor deposition. In the same manner as the organic layer 25, the metal film formed of the above material is broken by the rib 24, and is divided into one laminated on the organic layer 25 and one laminated on the rib 24. The layer stacked on the organic layer 25 becomes the second electrode 26. The second electrode 26 is orthogonal to (intersects with) the anode line 22a of the first electrode 22 in the light-emitting display unit 5, and a cathode line 26a for obtaining the matrix-shaped organic EL element 7, and the cathode line 26a and the second electrode 26a. It has a cathode terminal 26b that is interposed between the electrode line 22b of one electrode 22 and electrically connects them.

  The sealing member 27 is a flat plate member made of, for example, a glass material, and houses the light emitting display unit 5 including the organic EL element 7 including the first electrode 22, the insulating layer 23, the organic layer 25, and the second electrode 26. It has the recessed part 27a and the support part 27b formed so that the perimeter of this recessed part 27a may be enclosed. And the sealing member 27 and the translucent board | substrate are arrange | positioned on the translucent board | substrate 21 airtightly via the adhesive agent (not shown) which consists of support parts 27b, for example. 21 forms an airtight space 8 in which the organic EL element 7 is accommodated.

  The sealing member 27 is configured to be slightly smaller than the translucent substrate 21 so that the electrode lines 22b and 22c of the first electrode 22 are exposed to the outside. As a result, the first step portion 9 exposing the electrode line 22b and the second step portion 10 exposing the electrode line 22c are formed by the translucent substrate 21 and the sealing member 27 (see FIG. (See FIG. 1).

  In addition, the organic EL panel 2 smoothes the surface of the translucent substrate 21 by polishing the translucent substrate 21 including the first electrode 22 before the insulating layer 23 is formed, and then polishes the surface. By cleaning the translucent substrate 21 thus formed, foreign matters such as dust adhering to the translucent substrate 21 are removed.

  The driving substrate 3 is made of, for example, a hard circuit board in which a wiring pattern (not shown) is provided on a glass epoxy base material, and is arranged so that the plate surface thereof is substantially parallel to the plate surface of the organic EL panel 2. ing. The driving substrate 3 is electrically connected to the wiring pattern by driving means (not shown) for driving and controlling the organic EL panel 2 and various circuit components (not shown) such as resistors and capacitors. .

  Reference numeral 31 denotes a spacer member for arranging the drive substrate 3 in parallel with the organic EL panel 2 when the organic EL panel 2 and the drive substrate 3 are connected via the connection member 4. The spacer member 31 is formed, for example, as a plate material having a substantially “L” -shaped elasticity, and is provided with, for example, a double-sided adhesive tape on three driving substrates at positions facing the electrode lines 22 b and 22 c of the organic EL panel 2. It is arranged via. Further, the spacer member 31 may be formed of, for example, a hard material instead of a member having elasticity.

  In addition, 32 is a first electrode portion formed in a row on the driving substrate 3 so as to face the electrode line 22b of the first electrode 22 in the organic EL panel 2, and 33 is a first electrode portion in the organic EL panel 2. A plurality of second electrode portions formed in a row on the driving substrate 3 so as to face the electrode line 22c of the electrode 22, each of the electrode portions 32 and 33 is formed of, for example, a carbon electrode, An electrode is conductively connected to the wiring pattern.

  The connection member 4 includes a first flexible substrate 41 for electrically connecting the electrode line 22b of the organic EL panel 2 and the first electrode portion 32 of the driving substrate 3, and the electrode line 22c of the organic EL panel 2. And a second flexible substrate 42 for electrically connecting the second electrode portion 33 of the driving substrate 3 to the second electrode portion 33. Since the basic configurations of the flexible substrates 41 and 42 in this embodiment are the same, the basic configuration will be described below by taking the first flexible substrate 41 as an example, and the description of the second flexible substrate 42 will be described. Omitted.

  On the first flexible substrate 41, as shown in FIG. 7, predetermined circuit wiring 41a is formed of a flexible insulating material. Then, on one side of the circuit wiring 41 a, first connection terminals (second electrode terminals) 41 b that are electrically joined to the electrode lines 22 b of the organic EL panel 2 are arranged in a row along the width direction of the flexible substrate 41. Are provided in plurality. A plurality of second connection terminals 41 c that are electrically joined to the first electrode portion 32 of the driving substrate 3 are provided in a row along the width direction of the flexible substrate 41 on the other side of the circuit wiring 41 a. ing. Each of the connection terminals 41b and 41c is obtained by laminating a conductive material such as silver or gold on a copper foil, for example.

  Next, an example of assembling the display device in this embodiment will be described.

  Note that when the organic EL panel 2 and the driving substrate 3 are electrically connected using the first and second flexible substrates 41 and 42, the configurations of the flexible substrates 41 and 42 are the same. Only the connection means between the organic EL panel 2 and the drive substrate 3 by the flexible substrate 41 will be described, and the description of the connection means between the organic EL panel 2 and the drive substrate 3 by the second flexible substrate 42 will be omitted.

  7 shows the group of electrode lines 22b of the organic EL panel 2 and the first connection terminal 41b group of the first flexible substrate 41, and the first electrode portion 32 group of the driving substrate 3 and the first flexible substrate 41. It is a figure which shows the positional relationship of the 2nd connection terminal 41c group.

  First, each end portion of the first flexible substrate 41 facing the driving substrate 3 is aligned using the predetermined positioning means so that the first electrode portion 32 group and the second connection terminal 41 c group overlap each other. As shown in FIG. 8, the first electrode portion group 32 is electrically connected to the second connection terminal 41 c group by the anisotropic conductive film 11. Next, the electrode line 22b group in which the low-resistance layer 22e is partially laminated using a predetermined positioning means and the first connection terminal 41b group are aligned so that the organic EL of the first flexible substrate 41 is aligned. By thermocompression bonding each end facing the panel 2, the group of electrode lines 22b in which the low resistance layer 22e is partially laminated by the anisotropic conductive film 11 as shown in FIG. Is electrically connected.

  Next, the electrode line 22c of the organic EL panel 2 and the second electrode portion 33 of the driving substrate 3 are connected via the second flexible substrate 42, and then integrated via the flexible substrates 41 and 42. The organic EL panel 2 and the driving substrate 3 are accommodated in the front frame 1 so that the light emitting display portion 5 of the organic EL panel 2 faces the opening 1 a of the front frame 1. At this time, each outer wall surface of the translucent substrate 21 and each inner wall surface of the front frame 1 are positioned, so that each member including the organic EL panel 2, the driving substrate 3, and the connecting member 4 is placed in the front frame 1. It is designed to be stored and held. Finally, when each member is housed in the front frame 1, the drive substrate 3 is fixed to the front frame 1 by caulking the caulking piece 1 b protruding behind the drive substrate 3 toward the opening 1 a. This completes the assembly of the display device.

  In such an embodiment, the organic EL panel 2 polishes the translucent substrate 21 provided with the first electrode 22 before forming the insulating layer 23, and the polished translucent substrate 21 is put in the air. Further, when transported to the cleaning process, the low resistance layer 22e made of chromium further formed on the first electrode terminal 22d is oxidized, and an oxide film made of chromium oxide is formed on the entire surface of the low resistance layer 22e. Will be. However, in the present embodiment, when the low resistance layer 22e is formed in advance, a part of the first electrode terminal 22d is exposed through the non-formation region of the low resistance layer 22e, so that the organic EL panel 2 and the connection member 4 are exposed. Since a part of the first connection terminal 41b of the connection member 4 is in close contact with the exposed portion of the first electrode terminal 22d through the conductive particles (not shown) in the anisotropic conductive film 11 at the time of connection, the first The electrode terminal 22d (low resistance layer 22e) and the first connection terminal 41b are stably connected to each other, whereby the connection reliability between the organic EL panel 2 and the connection member 4 can be improved.

  In the present embodiment, the low resistance layer 22e is laminated on the first electrode terminal 22d so as to have a comb shape, and a part of the first electrode terminal 22d is exposed from the low resistance layer 22e. As described above, in the invention according to the first aspect of the present invention, the shape of the low resistance layer 22e is arbitrary as long as at least a part of the first electrode terminal 22d is exposed. The low resistance layer 22e is formed in a frame shape so as to surround the electrode terminal 22d, and the first electrode terminal 22d is partially exposed through a non-formation region of the low resistance layer 22e surrounded by the frame portion. May be.

  In the present embodiment, the case where the low resistance layer 22e is made of chromium has been described. However, for example, the low resistance layer 22e may be formed of a metallic conductive material made of a titanium-based compound. Or you may comprise a low resistance layer by laminating | stacking the metal electroconductive material which consists of multiple layers on the 1st electrode terminal 22d. Specifically, a first low resistance layer made of copper is formed on the surface of the first electrode terminal 22d, and a second low resistance layer made of chromium is further formed on the surface of the first low resistance layer. It is also possible.

  Further, since flexible substrates 41 and 42 having flexibility are used as connecting members to the driving substrate 3, an extra load is applied to the connection portion between the organic EL panel 2 (driving substrate 3) and the flexible substrates 41 and 42. Therefore, the connection reliability between the organic EL panel 2 (drive substrate 3) and the flexible substrates 41 and 42 can be further improved.

  In this embodiment, the organic EL panel 2 formed by forming a plurality of dot-matrix organic EL elements 7 in a row on the translucent substrate 21 and the drive substrate 3 are each flexible substrate 41, However, the present invention is not limited to this. For example, a plurality of organic EL elements 7 of segment type are formed on the translucent substrate 21. The organic EL panel 2 and the driving substrate 3 may be electrically connected by a flexible substrate.

  In this embodiment, the electrode line 22b group and the first connection terminal 41b group, and the electrode line 22c group and the second connection terminal 41c group are electrically joined by the anisotropic conductive film 11. The present invention is not limited to this, and may be joined using, for example, heat sealing.

  In the present embodiment, the example in which the low resistance layer 22e is formed only at the first electrode terminal 22d exposed from the sealing member 27 has been described. For example, the electrode line 22c side of the first electrode terminal 22d is provided. In this case, the low resistance layer 22e may be laminated on the electrode line 22c covered with the sealing member 27.

It is a perspective view of the organic electroluminescent panel in embodiment of this invention. It is sectional drawing of the organic electroluminescent panel in the same embodiment. It is principal part sectional drawing which shows the lamination | stacking state of the translucent board | substrate and 1st electrode terminal in the same embodiment. It is CC sectional drawing of FIG. It is AA sectional drawing of FIG. FIG. 3 is an enlarged plan view showing a main part B in FIG. 2. It is a top view which shows the positional relationship of the organic electroluminescent panel in the same embodiment, a circuit board, and a flexible substrate. It is sectional drawing which shows the joining state of the circuit board and flexible substrate in the embodiment. It is sectional drawing which shows the joining state of the organic electroluminescent panel and flexible substrate in the same embodiment.

Explanation of symbols

1 Front frame 2 Organic EL panel 3 Drive board (circuit board)
Reference Signs List 4 connection member 5 light emitting display 7 organic EL element 21 translucent substrate 22 first electrode 22a anode line (transparent electrode)
22b, 22c electrode line 22d first electrode terminal 22e low resistance layer 25 organic layer 26 second electrode (back electrode)
32 1st electrode part 33 2nd electrode part 41 1st flexible substrate 41a Circuit wiring 41b 1st connection terminal (2nd electrode terminal)
41c 2nd connection terminal 42 2nd flexible substrate

Claims (4)

An organic EL element disposed on a light-transmitting substrate and having an organic layer including at least a light-emitting layer sandwiched between a transparent electrode and a back electrode;
A first electrode terminal electrically connected to the transparent electrode and the back electrode and provided on the translucent substrate;
A connection member including a second electrode terminal electrically connected to the first electrode terminal;
An organic EL panel, wherein a low resistance layer having a resistivity lower than that of the transparent electrode is formed on the first electrode terminal so as to expose at least a part of the first electrode terminal. The organic EL panel according to claim 1, wherein the first electrode terminal and the second electrode terminal are electrically connected through an anisotropic conductive film or heat seal. The organic EL panel according to claim 1, wherein the connecting member is made of a flexible substrate having flexibility. 2. The organic EL panel according to claim 1, wherein the first electrode terminal is made of ITO, and the low-resistance layer is formed in a comb shape with respect to the ITO.

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