Electroluminescent light-emitting device and manufacturing method therefor

TECHNICAL FIELD

0001Embodiments of the present invention relate to an electroluminescent device and its manufacture method.

BACKGROUND

0002Organic light emitting diode (OLED), also called organic electroluminescence display (OELD), has been widely applied to mobile communication terminal, personal digital assistant (PDA) and palmtop computer for their various excellent properties such as self-luminescence, backlight needlessness, high contrast, thinness, broad visual angle, fast response, broad applicable temperature range, simple structure and simple manufacture process and so on.

0003OLED devices can be sorted into two categories: passive matrix OLED and active matrix OLED. In the case of active matrix OLED, the electric current through every OLED is controlled by the thin film transistor (TFT) circuit. Active matrix OLED possesses properties such as high luminescent efficiency and good image display effect.

0004As shown in <figref idref="f0001">figure 1</figref>, an active matrix OLED display device comprises a color film substrate 20 and an array substrate 10 opposite to each other. The color film substrate 20 comprises: substrate 21, and a color filter layer, a flat layer 23, a first electrode 24, an organic electroluminescence layer 25 and a second electrode 26 disposed on the substrate 21 orderly. The color filter layer comprises a black matrix 221 and color blocks 222 separated by the black matrix 221. The array substrate 10 comprises: a second substrate 11 and an array of thin film transistors 12, a protection layer 13 and a connection electrode 14 disposed on the substrate 11 orderly. The connection electrode 14 connects the drain of the thin film transistor 12 through the VIA of the protection layer. A frame sealing glue 30 is applied at the edge of the color film substrate 20 or the array substrate 10. The color film substrate 20 and the array substrate 10 have been connected oppositely, and the second electrode 26 and the connection electrode 14 on the array substrate 10 have been contacted correspondingly to achieve electrical conncction.

0005<patcit id="pcit0001" dnum="JP2010287421A"><text>JP2010287421A</text></patcit> discloses an organic EL element substrate, having a first electrode layer formed on a first base material, barrier ribs formed on the first base material to divide the first electrode layer, an organic light emitting medium layer formed on the first electrode layer, and a second electrode layer formed on the organic light emitting medium layer, is pasted on a sealing base material with an adhesive agent layer in-between. The sealing base material includes a second base material and a protruded layer formed on the second base material, and the protruded layer is so formed as to be positioned at openings between the barrier ribs.

0006<patcit id="pcit0002" dnum="US7309957B2"><text>US7309957B2</text></patcit> discloses an organic electroluminescent display device which includes first and second substrates bonded together, the first and second substrates having a plurality of pixel regions, a plurality of driving elements on an inner surface of the first substrate within each of the plurality of pixel regions, a plurality of connection electrodes contacting the driving elements, a black matrix on an inner surface of the second substrate at a boundary of each of the plurality of pixel regions, a color filter layer including red, green, and blue color filters on the inner surface of the second substrate, each of the red, green, and blue color filters corresponding to each of the plurality of pixel regions, a first electrode on the black matrix and the color filter layer, an organic electroluminescent layer on the first electrode, and at least one second electrode on the organic electroluminescent layer, wherein the at least one second electrode contacts the connection electrodes.

0007<patcit id="pcit0003" dnum="US20120168796A1"><text>US20120168796A1</text></patcit> discloses an organic light emitting diode (OLED) display which includes a substrate, a pixel electrode on the substrate, an organic light emitting member on the pixel electrode, a common electrode on the organic light emitting member, a thin film encapsulation member covering the common electrode, a black matrix on the thin film encapsulation member, and an upper protection film on the black matrix. The black matrix has a color filter at a location corresponding to the organic light emitting member. A sum of a thickness of the color filter and a distance between the color filter and the organic light emitting member is smaller than a width of the organic light emitting member.

0008<patcit id="pcit0004" dnum="US20100096655A1"><text>US20100096655A1</text></patcit> discloses an organic electroluminescent device which includes a first substrate including a plurality of pixel regions; a thin film transistor on the first substrate and in each pixel region; a second substrate facing the first substrate; an organic electroluminescent diode on the second substrate and connected to the thin film transistor; a seal pattern at edges of the first and second substrates; and an adhesive layer including a plurality of conductive balls, an inner space defined by the first substrate, the second substrate and the seal pattern filled with the adhesive layer.

SUMMARY

0009At least one embodiment of the present invention provides an electroluminescent device and its manufacture method according to the claims, in which the reliability of the electrical connection between the thin film transistor and the second electrode can be assured, and at the same time, the production efficiency can be improved by reducing the etching difficulty and the film forming time during the manufacture process of the connection electrode.

0010At least one embodiment of the present invention provides an electroluminescent device comprising a color film substrate; said color film substrate comprises: a substrate and a color filter layer, a boss layer, a first electrode, an organic electroluminescence layer and a second electrode disposed on the substrate; said color filter layer comprises a black matrix and color blocks separated by the black matrix; said boss layer uninterruptedly is disposed between said color filter layer and said first electrode; the boss layer located above said color blocks protrudes towards the side away from the substrate to form a boss; said first electrode, said organic electroluminescence layer and said second electrode are disposed on said boss layer orderly, and said second electrode is located above said boss, wherein the electroluminescent device further comprises an array substrate, wherein, said array substrate comprises: a second substrate, and thin film transistors, a protection layer and a connection electrode disposed on the second substrate orderly; a protection layer VIA is arranged in the protection layer, and the setting position of the connection electrode corresponds to the second electrode of the color film substrate, and the connection electrode connects the drain of the thin film transistors through the protection layer VIA, wherein the connection electrode is in direct contact with the second electrode of the color film substrate.

0011At least one embodiment of the present invention further provides a manufacture method of an electroluminescent device, comprising: manufacturing a color film substrate, which comprises forming on a substrate a color filter layer which comprises a black matrix and color blocks separated by the black matrix; forming a boss layer uninterruptedly on the substrate on which the color filter layer has been formed, and forming a boss above the color blocks; and forming a first electrode, an organic electroluminescence layer and a second electrode on the boss layer orderly, wherein the second electrode is located above the boss; wherein the manufacture method of preparing an electroluminescent device further comprises a step of manufacturing an array substrate, wherein, said array substrate comprises: a second substrate, and thin film transistors, a protection layer and a connection electrode disposed on the second substrate orderly; a protection layer VIA is arranged in the protection layer, and the setting position of the connection electrode corresponds to the second electrode of the color film substrate, and the connection electrode connects the drain of the thin film transistors through the protection layer VIA, wherein the connection electrode is in direct contact with the second electrode of the color film substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

0012In order to more clearly explain the embodiments of the present invention, some drawings related to the embodiments of the invention will be briefly described. Apparently, the drawings described below merely involve some embodiments of the present invention, and should not be understood as limitations on the present invention. <ul id="ul0001" list-style="none" compact="compact"><li><figref idref="f0001">Figure 1</figref> is a structurally schematic diagram of an active matrix OLED display device;</li><li><figref idref="f0001">Figure 2</figref> is a structurally schematic diagram 1 of an electroluminescent display device provided by one embodiment of the present invention;</li><li><figref idref="f0001">Figure 3(a)</figref> is a structurally schematic diagram 2 of an electroluminescent display device provided by another embodiment of the present invention;</li><li><figref idref="f0002">Figure 3(b)</figref> is a structurally schematic diagram 3 of an electroluminescent display device not forming part of the present invention;</li><li><figref idref="f0002">Figure 4</figref> is a flow chat of manufacturing a color film substrate in the manufacture method of an electroluminescent display device provided by one embodiment of the present invention;</li><li><figref idref="f0002">Figure 5(a)</figref> is a structurally schematic diagram of a substrate set with a color filter layer in one embodiment of the present invention;</li><li><figref idref="f0003">Figure 5(b)</figref> is a schematic diagram of exposure of a boss layer in one embodiment of the present invention;</li><li><figref idref="f0003">Figure 5(c)</figref> is a structurally schematic diagram of a boss layer after a composition process in one embodiment of the present invention;</li><li><figref idref="f0003">Figure 5(d)</figref> is a structurally schematic diagram of a color film substrate in one embodiment of the present invention;</li></ul>

0013Reference signs: 10- array substrate, 11- second substrate, 12- thin film transistor, 13- protection layer, 14- connection electrode, 20- color film substrate, 21-substrate, 221- black matrix, 222- color blocks, 23- flat layer, 24- first electrode, 25- organic electroluminescence layer, 26-second electrode, 27-boss layer, 271- boss, 30- frame sealing glue, 40- mask plate.

DETAILED DESCRIPTION

0014In order to make the aim, the technical details and the advantages of the embodiments of the invention apparent, the technical solutions of the embodiments will be described in a clearly and fully understandable way in connection with the drawings related to the embodiments of the invention. Apparently, the described embodiments are just part of but not all of the embodiments of the invention. Based on the described embodiments herein, those skilled in the art can obtain other embodiments without any inventive work, which should be within the scope of the invention.

0015In the structure shown in <figref idref="f0001">figure 1</figref>, the connection electrode 14 is generally manufactured relatively thick (from 2 -to 3 µm) so as to fully contact the connection electrode 14 and the second electrode 26 after cell-assembling and improve the reliability of the electrical connection of the thin film transistor 12 and the second electrode 26. However, when the connection electrode 14 is manufactured, it takes a long time to form the thin film and it is difficult to etch the thin film.

0016At least one embodiment of the present invention provides an electroluminescent device, as shown in <figref idref="f0001">figure 2</figref>, which comprises a color film substrate 20. The color film substrate 20 comprises: a substrate 21, and a color filter layer, a first electrode 24, an organic electroluminescence layer 25 and a second electrode 26 disposed on the substrate 21. The color filter layer comprises: a black matrix 221 (BM) and color blocks 222 (for example the red, green and blue R/G/B in the figure) separated by the black matrix 221. The color film substrate 20 further comprises a boss layer 27; the boss layer 27 is disposed between the color filter layer and the first electrode 24; the boss layer 27 located above the color blocks (R/G/B) 222, protrudes towards the side away from the substrate 21 to form a boss 271. The first electrode 24, the organic electroluminescence layer 25 and the second electrode 26 arc disposed on the boss layer 27 orderly, and the second electrode 26 is located above the boss 271.

0017An active matrix electroluminescent device comprises a color film substrate 20 and an array substrate 10, and the color film substrate 20 is provided with a color filter layer and a luminescent OLED device. The luminescent OLED device comprises a first electrode 24, an organic electroluminescence layer 25 and a second electrode 26. The array substrate 10 is provided with TFT circuits (driving circuits) for driving and compensating the OLED. There are many ways to realize the driving circuits, however, the driving circuits should at least comprise a thin film transistor for driving. The thin film transistor 12 in at least one embodiment of the invention refers to a thin film transistor in driving circuits for driving. The drain of the thin film transistors 12 is introduced by the connection electrode 14. Through abutment of the second electrode 26 of the OLED and the connection electrode 14 on the array substrate 10 after combination of the color film substrate 20 with the array substrate 10, the electrical connection between the thin film transistor and the luminescent device is realized, and the electrical connection between the driving circuits and the luminescent device is realized.

0018At least one embodiment of the present invention raises up the second electrode 26 by adding the boss layer 27 with a boss, thus further reduces the thickness of the connection electrode 14 on the array substrate (e. g. the thickness can be reduced to from 0.3 to 1 micrometer). As a result, the film forming time in the manufacture process of the connection electrode 14 is reduced, and the difficulty of the etching is reduced, thereby improving the production efficiency. At the same time, through elevation of the second electrode 26, the reliability of the electrical connection between the thin film transistors and the second electrode 26 can be assured, and the damages caused by the crash and friction between the color film substrate and the array substrate during and after the cell-assembling process can be avoided, thereby improving the qualification yield.

0019It should be explained that, the realization mode of the driving circuit has no direct relation with the present invention, and dose not affect the implementation effects of the embodiments of the present invention, either. Therefore, the realization mode of the driving circuit is not limited in the embodiments of the present invention, and it can be any realization mode known by a person skilled in the art.

0020In at least one embodiment of the present invention, an electrode for docking with the connection electrode 14 can be further provided. For example, a protection layer is placed on the second electrode 26, and the second electrode 26 is introduced through the VIA provided in the protection layer to connect with the docking electrode. In this case, the second electrode in the present embodiment can further comprise a docking electrode connected to it.

0021The boss layer 27 can be manufactured from one of the following materials, or can be a composite film manufactured from a plurality of the following materials: silicon nitride, silicon oxide or photosensitive resin. Said photosensitive resin can be made of polyacrylic acid resin class, polyimide resin class or polyamide resin class. Refer to <figref idref="f0003">figure 5(c)</figref>, for example, the total thickness d2 of the obtained boss layer 27 is from 2 to 4 micrometers. The boss 271 is formed at the position of the boss layer 27 corresponding to the color blocks 222 (red/green/blue, i.e., R/G/B in the figure)through composition processes such as coating, exposure, developing and etching. The shoulder height d1 of the boss 271 is for example from 1.5 to 2.5 micrometers. In another embodiment, if the boss layer 27 is made of photosensitive resin, only the exposure and developing processes are needed to form the boss 271.

0022In at least one embodiment of the present invention, said color film substrate 20 may further comprise a flat layer 23, which is disposed between the color filter film and the boss layer 27.

0023In at least one embodiment of the present invention, as shown in <figref idref="f0001">figure 3(a)</figref>, after a flat layer 23 is manufactured on a color filter layer, a boss layer 27 may be formed on the flat layer 23, and the boss layer 27 is provided with a boss 271. In addition, as shown in <figref idref="f0002">figure 3(b)</figref>, after a flat layer 23 is manufactured on a color filter layer, a boss 271 may be formed on the flat layer 23, the flat layer 23 together with the boss 271 constitutes a boss layer 27 not forming part of the present invention.

0024In at least one embodiment of the present invention, the array substrate 10 may comprise: a second substrate 11, and thin film transistors 12, a protection layer 13 and a connection electrode 14 disposed on the second substrate 11 orderly; a VIA is arranged in the protection layer 13; the connection electrode 14 is placed at a position corresponding to the second electrode 26 of the color film substrate 20, and the connection electrode 14 connects the drain of the thin film transistors 12 through the VIA of the protection layer.

0025The thickness of the connection electrode 14 is for example from 0.3 to 1 micrometer. Compared with for example the connection electrode in <figref idref="f0001">figure 1</figref> with a thickness from 2 to 3 micrometers, the thickness of the connection electrode 14 has been significantly reduced, and thus the time of depositing the connection electrode has been saved. As a result, the production efficiency can be improved by reducing the etching difficulty and simplifying the process in the following etching step.

0026Said connection electrode 14 may be made from one or several materials selected from: copper, molybdenum, tin, aluminum and silver. Said protection layer 13 may be made from one or several materials selected from: silicon nitride, silicon oxide or photosensitive resin.

0027At least one embodiment of the present invention provides an electroluminescent device, in which the thickness of the connection electrode can be further reduced, thereby improving the production efficiency due to reducing the etching difficulty and the film forming time during the manufacture process of the connection electrode; at the same time, by elevating the connection electrode, the reliability of the electrical connection between the thin film transistor and the second electrode can be assured, and the damages caused by the crash and friction between the color film substrate and the array substrate during and after the cell-assembling process can be avoided, thereby improving the qualification yield.

0028The electroluminescent device provided by at least one embodiment of the present invention may be: any products or components with display function such as electronic paper, mobile phones, Flat PC, televisions, monitors, laptop computer, digital frames or navigators.

0029At least one embodiment of the present invention provides a manufacture method of electroluminescent device, which comprises: manufacturing the color film substrate, manufacturing the array substrate, and cell-assembling of the color film substrate and the array substrate. In one embodiment, as shown in <figref idref="f0002">figure 4</figref>, manufacturing the color film substrate may include the following steps: <ul id="ul0002" list-style="none" compact="compact"><li>Step 101: forming a color filter layer on the substrate 21, as shown in <figref idref="f0002">figure 5(a)</figref>, said color filter layer comprises: black matrix 221 and color blocks 222 (for example the R/G/B color blocks in the figure) separated by the black matrix 221;</li><li>Step 102: as shown in <figref idref="f0003">figure 5(c)</figref>, forming a boss layer 27 on the substrate 21 having the color filter layer, and forming a boss 271 above the color blocks 222 through a composition process.</li><li>Step 103: as shown in <figref idref="f0003">figure 5(d)</figref>, forming a first electrode 24, an organic electroluminescence layer 25 and a second electrode 26 on the boss layer 27 sequentially, wherein the second electrode 26 is located above the boss 271;</li></ul>

0030Forming the color filter layer in step 101, and forming the first electrode 24, the organic electroluminescence layer 25 and the second electrode 26 in step 103 will not be detailed herein for this embodiment again.

0031The boss layer 27 with the boss is formed in step 102. If the boss layer 27 is made from photosensitive resin, it may be realized for example by the following method: applying photosensitive resin to form the boss layer 27; as shown in <figref idref="f0003">figure 5(b)</figref>, controlling the exposure using a mask, and forming the boss 271 of the boss layer 27 on the color blocks 222 after the exposure and developing (the color blocks R/G/B as shown in the figure), as shown in <figref idref="f0003">figure 5(c)</figref>.

0032If non-photosensitive materials such as silicon nitride or silicon oxide are used, in order to from the boss 271 on the boss layer 27, several composition processes such as coating, exposure, developing and etching are required.

0033In addition, if the flatness of the color filter layer is not sufficient, the quality of the films produced in the succeeding steps will be harmed. Therefore, a flat layer may be manufactured on the color filter layer using silicon nitride or silicon oxide. In at least one embodiment of the present invention, the flat layer can be omitted if the boss layer 27 is arranged on the color filter layer. The flatness of the color filter substrate, especially the flatness of the pixel area having significant influence on the display quality, can be leveled by the boss layer 27 so as to satisfy the design requirements.

0034Of course, the flat layer may not be omitted in at least one embodiment of the present invention. For example: after the color filter layer being formed (step 101), and before step 102, the above method may further comprise: forming a flat layer 23 on the substrate with the color filter layer (refer to <figref idref="f0001">figure 3(a)</figref>). Then, step 102 may be carried out, forming the boss 271 on the flat layer 23. The other steps are the same as above.

0035The contents described above are related to manufacturing the color film substrate. Manufacturing the array substrate in at least one embodiment of the present invention may employ any processes known in the art. The position of the connection electrode 14 on the array substrate 10 is correlated with the boss 271 of the color film substrate 20, and the thickness of the connection electrode 14 is reduced (the thickness of the connection electrode 14 may be from 0.3 to 1 micrometer), and in the succeeding cell-assembling process of the color film substrate and the array substrate, the second electrode 26 arranged on the boss 271 contacts the thin film connection electrode 14 to realize electrical connection.

0036To sum up, in the manufacture method of the electroluminescent device according to the present embodiment, by adding a boss below the second electrode 26, the second electrode 26 can be elevated and the thickness of the connection electrode 14 can be reduced. Therefore, the production efficiency can be improved by reducing the etching difficulty and the film forming time during the manufacture process of the connection electrode 14; at the same time, by elevating the second electrode 26, the reliability of the electrical connection between the thin film transistor 22 and the second electrode 26 can be assured, and the damages caused by the crash and friction between the color film substrate 20 and the array substrate 10 during and after the cell-assembling process can be avoided, thereby improving the qualification yield.

0037It should be noted that, the technical features in the present embodiment can be used in any combination if there is no confliction.

0038The invention has been described with reference to some exemplary embodiments which are not limitative to the scope of the disclosure. The scope of the disclosure is defined by the accompanying claims.

0039The present application claims the benefits of the Chinese Application No. <patcit id="pcit0005" dnum="CN201310436163X"><text>201310436163.X filed on September 23, 2013</text></patcit>.