JP2005050773A - Organic led element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To leave no uncured resin component in an ultraviolet curing type resin in securing stability and weatherability of connection by applying a reinforcing resin (especially ultraviolet curing type resin) to a connecting part of a terminal part of an organic LED element and the external circuit board. <P>SOLUTION: After the external circuit board (flexible wiring circuit board) 50 is connected to the terminal part 10a of the organic LED element via an anisotropic conductive film 60, when the ultraviolet curing type resin 70 is applied to that connecting part, so that the ultraviolet cure type resin 70 may not enter the connecting part, barriers 110, 120 composed of the resin is installed between the terminal part 10a and the external circuit board 50. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an organic LED element in which an anode electrode and a cathode electrode are arranged on both sides of an EL forming layer containing an organic light emitting material. More specifically, the reliability of a connection portion between the terminal portion and an external circuit board is described. It is about the technology which raises.

  An organic LED element (Organic Light Emitting Diode Device) is also referred to as an organic EL (Electro Luminescence) element, and includes a light-transmitting substrate (in many cases, a glass substrate) 10 as shown in FIG. The light-transmitting substrate 10 has a configuration in which an anode electrode 20, an EL formation layer 30 containing an organic light emitting material, and a cathode electrode 40 are sequentially stacked on one side of the light-transmitting substrate 10.

  An example of the configuration will be described more specifically with reference to FIGS. 7A to 7C. First, as shown in FIG. 7A, ITO (indium tin oxide) is formed on one surface of the glass substrate 10. ) After the anode electrode 20 made of a material is formed in a stripe shape, an opening insulating film 11 is formed on the anode electrode 20 so as to partially leave a window frame-like opening and cover other portions. A partition wall 12 is formed on the insulating film 11 in a direction orthogonal to the anode electrode 20.

  Next, as shown in FIG. 7B, an EL forming layer 30 containing an organic light emitting material is deposited between the partition walls 12 via the metal mask 13 by vapor deposition, and then as shown in FIG. 7C. Then, the cathode electrode 40 is deposited on the EL forming layer 30.

  As shown in FIG. 8, the glass substrate 10 includes a terminal portion 10a connected to an external circuit substrate, and the electrode terminals of the anode electrode 20 and the cathode electrode 40 are drawn out to the terminal portion 10a. For convenience, only the electrode terminal 41 of the cathode electrode 40 is shown.

  For example, as described in Patent Document 1, since the organic LED element is a current injection type element, the light emission efficiency greatly depends on the resistance value of the electrode wiring. In particular, since a large amount of current flows instantaneously through the cathode electrode, an auxiliary electrode 41a made of a metal material is provided at the electrode terminal 41 of the cathode electrode 40 in order to reduce the resistance of the wiring.

  In many cases, the external circuit board connected to the terminal portion 10a is the flexible wiring board 50 as in the case of the liquid crystal display element. That is, the flexible wiring board 50 is used as a relay board that connects a display drive control circuit board (not shown) and the organic LED element, and a lead electrode (not shown) corresponding to the electrode terminal on the organic LED element side is connected to the connection terminal portion. ).

  An anisotropic conductive film (ACF) 60 is often used for connection between the terminal portion 10a and the flexible wiring board 50. The anisotropic conductive film 60 is, for example, a film in which conductive particles are contained in a thermosetting resin, and electrically and mechanically connects the terminal portion 10a and the flexible wiring board 50 through thermocompression bonding.

  After the connection, reinforcing resin is applied to the connection portion between the terminal portion 10a and the flexible wiring board 50 in order to maintain reliability, that is, to secure the stability and weather resistance of the connection. As the reinforcing resin, an ultraviolet curable resin 70 is generally used because the organic LED element dislikes heat and can be cured in a short time.

  When the ultraviolet curable resin is cured, an unreacted resin component is left if the amount of ultraviolet irradiation is insufficient. In the connecting portion between the terminal portion 10a and the flexible wiring board 50, the base film of the flexible wiring board 50 is opaque, and the auxiliary electrode 41a formed on the electrode terminal 41 is also made of a metal material and has a light shielding property. Therefore, the resin entering between them (resin in the circled portion A in FIG. 8) tends to have an insufficient ultraviolet irradiation amount.

As described above, when an uncured ultraviolet curable resin is left at the connection portion between the terminal portion 10a and the flexible wiring board 50, the moisture resistance performance is lowered, and the electrode terminal may be corroded due to intrusion of moisture. Another undesired phenomenon is that the unreacted resin component and the metal material of the auxiliary electrode 41a cause a chemical reaction to cause corrosion at the electrode terminal.
JP 11-317292 A

  Therefore, the problem of the present invention is that when the reinforcing resin is applied to the connection portion between the terminal portion of the organic LED element and the external circuit board to ensure the stability and weather resistance of the connection, the uncured resin component of the reinforcing resin is The purpose is to prevent the connection part from entering.

  In order to solve the above-described problems, the present invention includes a light-transmitting substrate including a light-emitting display region and a terminal portion, and includes an anode electrode and an organic light-emitting material in the light-emitting display region. An EL forming layer and a cathode electrode are formed, and each electrode terminal of the anode electrode and the cathode electrode is drawn out to the terminal portion, and an external electrode having a lead electrode corresponding to each electrode terminal in the terminal portion In an organic LED element in which a circuit board is connected via an anisotropic conductive adhesive, and a reinforcing resin is provided to reinforce a connection portion by the anisotropic conductive adhesive, the terminal portion and the external circuit board A barrier is provided between them to prevent the reinforcing resin from entering the connecting portion.

The present invention includes several embodiments described below. That is, claim 2 includes an aspect in which the barrier is disposed at a connection portion between the electrode terminal having at least a metallic auxiliary electrode among the electrode terminals and the external circuit board.
According to a third aspect of the present invention, the barrier is disposed at least on the edge side of the external circuit board between the terminal portion and the external circuit board.
According to a fourth aspect of the present invention, the barrier is disposed on both the edge side of the external circuit board and the edge side of the terminal part between the terminal part and the external circuit board.
The aspect arrange | positioned so that the said barrier arrange | positioned at the edge side of the said terminal part may be covered so that the end surface of the said electrode terminal may be covered as Claim 5.
A sixth aspect of the present invention includes an aspect in which the barrier is disposed so as to enter between the electrode terminals.
A seventh aspect of the present invention includes an aspect in which the barrier is formed on the terminal portion side by a constituent material together with the partition wall or the opening insulating film included in the EL formation layer.
An aspect in which the barrier is integrally formed on the external circuit board side is included.
The ninth aspect includes an aspect in which the barrier is made of a resist resin that covers the surface of the external circuit board.
Further, as the tenth aspect, in the case where the barrier is arranged on both the edge side of the external circuit board and the edge side of the terminal part between the terminal part and the external circuit board, one barrier is The aspect formed in the said terminal part side and the other barrier is formed in the said external circuit board side is contained.
Further, claim 11 includes an embodiment in which the reinforcing resin is an ultraviolet curable resin.
A twelfth aspect includes an aspect in which the auxiliary electrode is a metal material containing molybdenum or a molybdenum alloy.

  According to the present invention, the presence of the barrier prevents the reinforcement resin from entering between the connection portion between the terminal portion and the external circuit board, and there is almost no possibility that an unreacted resin component remains in the connection portion. The stability and weather resistance of the connection can be ensured over a long period of time.

  Next, some embodiments of the present invention will be described with reference to FIGS. 1 to 5, but the present invention is not limited thereto. In the description of this embodiment, the same reference numerals are used for components that may be regarded as the same as or the same as those of the conventional example described with reference to FIGS.

  First, a first embodiment of the present invention will be described with reference to FIGS. 1 (a) and 1 (b). FIG. 1A is a cross-sectional view showing a connection portion between the terminal portion 10a and the flexible wiring board 50, and FIG. 1B is a plan view showing the terminal portion 10a before connection.

  In the present invention, the configuration on the light emitting unit side including the anode electrode, the EL formation layer, and the cathode electrode may be the same as the conventional example described above. 1 (a) and 1 (b) show only the electrode terminal 41 on the cathode electrode side made of an ITO material on which a metal auxiliary electrode 41a is formed in order to reduce the resistance of the wiring. Does not exclude electrode terminals made of ITO material on the anode electrode side.

  The terminal portion 10 a and the flexible wiring board 50 are electrically and mechanically connected via the anisotropic conductive film 60. An anisotropic conductive resin liquid may be used instead of the anisotropic conductive film. In order to ensure the stability and weather resistance of the connection, an ultraviolet curable resin 70 as a reinforcing resin is applied along both ends of the connection portion between the terminal portion 10a and the flexible wiring board 50. In order to prevent entry into the barrier, a barrier is provided in the connecting part.

  In the first embodiment, barriers 110 and 120 are provided on both sides of the connection portion, respectively. That is, one barrier 110 is disposed on the edge 50E side of the flexible wiring board 50, and the other barrier 120 is disposed on the edge 10aE side of the terminal portion 10a. As shown in FIG. 1B, the barriers 110 and 120 are arranged in parallel to each other so as to cross the electrode terminal 41.

  In some cases, the barrier 110 may not be disposed on the end edge 10aE side of the terminal portion 10a, but the barrier 110 may be disposed only on the end edge 50E side of the flexible wiring board 50. include.

  The terminal portion 10a and the flexible wiring board 50 are connected via the anisotropic conductive film 60 in a state where the barriers 110 and 120 are formed on the terminal portion 10a side. The barriers 110 and 120 are not particularly limited as long as they are formed of a resin material and can prevent the ultraviolet curable resin 70 from entering, but from the viewpoint of reducing the number of manufacturing steps, It is preferably formed from the same material as the opening insulating film 11 or the partition 12 described in (a).

  As a modified example, as shown in FIG. 2, in addition to the pair of left and right barriers 110 and 120 described above, a barrier 130 is further formed between the electrode terminals 41 so that only the contact portion of the electrode terminal 41 has a window shape. You may open it. As another modification, as shown in FIG. 3, the width of the barrier 120 arranged on the end edge 10aE side of the terminal portion 10a is widened so that the end surface 41E of the electrode terminal 41 is covered with the one end portion 121 thereof. It is preferable to do.

  In the first embodiment, the barriers 110 and 120 are formed on the terminal portion 10a side. However, as the second embodiment of the present invention, as shown in FIG. Barriers 210 and 220 corresponding to the barriers 110 and 120 can also be formed. In this case, the barriers 210 and 220 can be formed of a predetermined resin material, but are preferably formed of a resist resin that covers the wiring of the flexible wiring board 50.

  The second embodiment can be modified as shown in FIGS. 4B and 4C. That is, as shown in FIG. 4B, one barrier 210 may be formed on the edge 50E side of the flexible wiring board 50, and the other barrier 120 may be formed on the edge 10aE side of the terminal portion 10a. Further, as shown in FIG. 4C, one barrier 110 may be formed on the terminal portion 10a side, and the other barrier 220 may be formed on the flexible wiring board 50 side.

  Next, with reference to Fig.5 (a)-(e), the manufacturing process of one board | substrate by the side which has the terminal part of the organic LED element which concerns on this invention is demonstrated. In FIG. 5A, assuming that the right side portion of the dotted line of the glass substrate 10 is assigned to the terminal portion 10a and the left side portion is assigned to the light emitting display region 10b, first, the anode electrode 20 and the cathode electrode side on the glass substrate 10 The electrode terminal 41 is formed of an ITO material. At that time, one end side of the anode electrode 20 is pulled out as an electrode terminal 21 to the terminal portion 10a side. The electrode terminal 41 on the cathode electrode side is also drawn out from the lead wiring portion on the light emitting display region 10b side to the terminal portion 10a side. The film thickness of the ITO material is about 0.16 μm.

  Next, as shown in FIG. 5B, the auxiliary electrode 41a made of a laminated film of molybdenum (Mo) or Mo alloy and Al is formed on the electrode terminal 41 on the cathode electrode side, including the routing wiring portion. . The same type of auxiliary electrode may be formed on the electrode terminal 21 on the anode electrode side. Then, as shown in FIG. 5C, in the light emitting display region 10b, the opening insulating film 11 is formed to a thickness of about 0.8 μm with, for example, polyimide resin.

  The opening insulating film 11 is for providing a window-like opening 11a as a pixel unit on the anode electrode 20, and covers the edge of the anode electrode 20 in order to prevent a short circuit between the anode electrodes 20. It is preferable to form. Subsequently, a plurality of rows of partition walls 12 having a thickness of about 3.5 μm are formed on the opening insulating film 11 in a direction orthogonal to the anode electrode 20 by using, for example, cresol resin.

  When forming this partition 12, the barrier 110 is formed in the terminal part 10a with the same material (cresol resin) as the partition 12 simultaneously. In this example, in FIG. 1A, only the barrier 110 located on the edge 50E side of the flexible wiring board 50 is formed over the electrode terminal 21 on the anode electrode side and the electrode terminal 41 on the cathode electrode side. You may arrange | position only on the electrode terminal 41 by the side of the cathode electrode which has the electrode 41a. Preferably, the other barrier 120 is also formed.

  In addition to this, when forming the opening insulating film 11, a barrier may be formed of polyimide resin at the same time. In any case, a minimum film thickness of 0.5 μm is necessary as a barrier.

  Next, as illustrated in FIG. 5D, an EL formation layer 30 is formed between the partition walls 12. In the case of a low molecular light emitting device, the EL formation layer 30 includes a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer. Then, as a final step in this description, as shown in FIG. 5E, a cathode electrode 40 having a thickness of 0.15 μm is formed on the EL formation layer 30 by using, for example, an Al material so as to be connected to the electrode terminal 41. Note that a thermosetting resin may be used as the reinforcing resin instead of the ultraviolet curable resin.

As an embodiment of the present invention, first, an anode electrode made of an ITO material is patterned on a glass substrate so as to include an electrode terminal extending to the terminal portion, and an auxiliary electrode made of a molybdenum (Mo) alloy is formed on the electrode terminal. Formed. Next, a barrier was formed with a photosensitive polyimide resin at a predetermined position of the terminal portion at the same time as a partition was formed with photosensitive polyimide resin between the pixels in the light emitting display region.
Then, an EL formation layer including a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer is formed on the anode electrode serving as a pixel, and a cathode electrode made of aluminum is formed on the EL formation layer. One substrate was formed by forming. This board | substrate and the glass substrate as a counter substrate were bonded together through the periphery sealing material, and the organic LED element was obtained.
Next, after crimping and connecting a flexible wiring board to the terminal portion of the organic LED element via an anisotropic conductive film, an ultraviolet curable resin is applied to reinforce the connection portion, Both were cured by irradiating with ultraviolet rays.
In parallel with this, an organic LED element as a comparative example in which a flexible wiring board is connected through the same process as the above example except that a barrier is not formed in the terminal portion was produced.
The example of the present invention and the comparative example were left in a high-temperature and high-humidity environment at 80 ° C. and a relative humidity of 90% to examine whether or not the auxiliary electrode was corroded. In this case, no corrosion was observed even after 1000 hours. On the other hand, in the comparative example, the auxiliary electrode was corroded when about 250 hours passed, and the auxiliary electrode almost disappeared after about 500 hours.

The principal part expanded sectional view which shows 1st Embodiment of this invention. The top view which shows typically the terminal part of Fig.1 (a). The top view which shows typically the terminal part which concerns on the modification of the said 1st Embodiment. The principal part expanded sectional view which shows another modification of the said 1st Embodiment. The principal part expanded sectional view which shows 2nd Embodiment of this invention. The principal part expanded sectional view which shows the modification of the said 2nd Embodiment. The principal part expanded sectional view which shows another modification of the said 2nd Embodiment. The top view which shows typically the 1st process in the manufacturing process of one board | substrate with which the organic LED element of this invention is provided. The top view which shows typically the 2nd process in the manufacturing process of one board | substrate with which the organic LED element of this invention is provided. The top view which shows typically the 3rd process in the manufacturing process of one board | substrate with which the organic LED element of this invention is provided. The top view which shows typically the 4th process in the manufacturing process of one board | substrate with which the organic LED element of this invention is provided. The top view which shows typically the 5th process in the manufacturing process of one board | substrate with which the organic LED element of this invention is provided. The schematic diagram which shows the basic composition of an organic LED element. The typical perspective view which shows the 1st manufacturing process of the light emission part of an organic LED element. Typical sectional drawing which shows the 2nd manufacturing process of the light emission part of an organic LED element. Typical sectional drawing which shows the 3rd manufacturing process of the light emission part of an organic LED element. Sectional drawing which shows the prior art example of the connection part of an organic LED element and an external circuit board.

Explanation of symbols

10 Light transmissive substrate (glass substrate)
DESCRIPTION OF SYMBOLS 10a Terminal part 10b Light emission display area 11 Opening insulating film 12 Partition 20 Anode electrode 21 Electrode terminal on the anode electrode side 30 EL formation layer 40 Cathode electrode 41 Electrode terminal on the cathode electrode side 41a Auxiliary electrode 50 External circuit board (flexible wiring board)
60 Anisotropic conductive film 70 UV curable resin 110, 120, 130, 210, 220 Barrier

Claims (12)

A light-transmitting substrate including a light-emitting display region and a terminal portion, and an anode electrode, an EL formation layer including an organic light-emitting material, and a cathode electrode are formed in the light-emitting display region; Each electrode terminal of the cathode electrode is drawn out, and an external circuit board having a lead electrode corresponding to each electrode terminal is connected to the terminal portion via an anisotropic conductive adhesive, and the anisotropic conductive bond In the organic LED element provided with a reinforced resin that reinforces the connection part by the material,
An organic LED element, wherein a barrier is provided between the terminal portion and the external circuit board to prevent the reinforcing resin from entering the connecting portion.   2. The organic LED element according to claim 1, wherein the barrier is disposed at a connection portion between the electrode terminal having at least a metallic auxiliary electrode among the electrode terminals and the external circuit board.   The organic LED element according to claim 1, wherein the barrier is disposed at least on an edge side of the external circuit board between the terminal portion and the external circuit board.   3. The organic LED element according to claim 1, wherein the barrier is disposed both on an edge side of the external circuit board between the terminal part and the external circuit board and on an edge side of the terminal part.   The organic LED element according to claim 4, wherein the barrier disposed on the edge side of the terminal portion is disposed so as to cover the end surface of the electrode terminal.   The organic LED element according to claim 4 or 5, wherein the barrier is disposed so as to penetrate between the electrode terminals.   The organic LED element according to any one of claims 1 to 6, wherein the barrier is formed on the terminal portion side by a constituent material together with a partition wall or an opening insulating film included in the EL formation layer.   The organic LED element according to any one of claims 1 to 6, wherein the barrier is integrally formed on the external circuit board side.   The organic LED element according to claim 8, wherein the barrier is made of a resist resin covering a surface of the external circuit board.   When the barrier is disposed on both the edge side of the external circuit board and the edge side of the terminal part between the terminal part and the external circuit board, one barrier is formed on the terminal part side. The organic LED element according to claim 4, wherein the other barrier is formed on the external circuit board side.   The organic LED element according to any one of claims 1 to 10, wherein the reinforcing resin is an ultraviolet curable resin.   The organic LED element according to claim 2, wherein the auxiliary electrode is a metal material containing molybdenum or a molybdenum alloy.

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