Patent Description:
In recent years, OLED (OLED hereinafter) panels have gradually become the mainstream of mobile display terminal screens and display screens. An OLED panel includes a plurality of sub-pixels arranged in an array, where each sub-pixel includes a pixel driving circuit and a light-emitting element electrically connected to the pixel driving circuit.

In the related art, each light-emitting element includes multiple layers stacked up in sequence: an anode, a hole transport layer, a light-emitting layer, an electron transport layer and a cathode. In order to achieve high sub-pixel density in a display panel or to manufacture a display panel on a tiny silicon chip, a convenient approach is to continuously deposit the hole transport layer, the light-emitting layer, the electron transport layer and the cathode without pixeled shadow mask. The separation of sub-pixels is realized by a pixel definition layer. Furthermore, to prevent or reduce lateral charge diffusion in the hole transport layer, some unique structures, such as sidewall with inversed slope, are created in the pixel definition layer to disrupt the continuity of the hole transport layer.

The thickness of the cathode film is generally made relatively thin to allow OLED light passing through. Uneven surface topology of the OLED panel is another cause to make the cathode film even thinner at the sidewalls or slopes of the pixel definition layer. Large resistance of cathode film is therefore inevitable with ordinary design. External supplied voltage for OLED bias will be attenuated across the entire OLED panel, which is a "voltage drop" mechanism similar to what is frequently observed along power supply line of OLED. It is therefore a primary objective of this disclosure to provide a solution to overcome the said voltage drop on the cathode film. <CIT> introduces about a display device having a light-emitting layer disposed between electrodes. <CIT> introduces about an organic electroluminescence display panel having elastomers located on the pixel defining layer. <CIT> introduces about an electroluminescent device having an auxiliary electrode layer in contact with the first electrode for electrical connection. <CIT> introduces an organic electroluminescent display panel in which the problem of pixel crosstalk caused by transverse electric conduction of a charge generation layer is alleviated or avoided.

An OLED panel and a manufacturing method thereof are provided in embodiments of the present disclosure to minimize the nonuniformity of light emission caused by the voltage drop on the cathode film. The invention provides an organic light-emitting display, OLED, panel, comprising a light-emitting substrate (<NUM>) and a color filter substrate (<NUM>) disposed in parallel to the light-emitting substrate (<NUM>); wherein.

In a first aspect, an OLED panel is provided and includes a light-emitting and a color filter substrate disposed in parallel to the light-emitting.

The light-emitting substrate includes: a first substrate, a first electrode layer, a pixel definition layer, a light-emitting layer including a hole injection layer and a second electrode layer; the first electrode layer includes a plurality of first electrodes and is disposed on the first substrate; the pixel definition layer is disposed on the first electrodes and includes a plurality of first opening structures, to exposes part of the first electrodes; the hole transport layer, light-emitting layer, electron transport layer and the second electrode layer are successively disposed on the exposed first electrodes.

The color filter substrate includes: a second substrate, a conductive layer, a color filter layer, a wall-shaped elastic conductor wearing a metal cap; the conductive layer is disposed on a surface of the second substrate facing towards the light-emitting substrate; the color filter layer is disposed on the same surface and overlapped on the conductive layer; the color filter layer includes a plurality of sub-pixel color filters arranged in an array with a gap between each two adjacent color filters, that a portion of the conductive layer is then exposed through the gap; the elastic conductor is sitting on the conductive layer at the gaps, so as to have a same voltage as the conductive layer; the metal cap is disposed on the top of the elastic conductor facing towards the light-emitting substrate.

By aligning the light-emitting substrate and the color filter substrate in such a manner that a vertical projection of the elastic conductor on the first substrate is overlapped with a vertical projection of the pixel definition layer on the first substrate.

Disclosed herein but not recited by the wording of the claims is a manufacturing method of an OLED panel is provided in the embodiments of the present disclosure and includes steps described below.

A first electrode layer, a pixel definition layer, a hole transport layer, a light-emitting layer including a hole injection layer, an electron transport layer and a second electrode layer are successively formed on a first substrate, where the first electrode layer includes a plurality of isolated first electrodes, the pixel definition layer includes a plurality of first opening structures allowing the hole transport layer to contact to the first electrodes.

A conductive layer and a color filter layer are formed on a second substrate, where the color filter layer includes a plurality of sub-pixel color filters, and a gap between any two adjacent sub-pixel color filters is created to expose the conductive layer in the gap region.

A wall-shaped elastic conductor wearing a metal cap is formed on the second substrate, that the bottom of the elastic conductor is in contact with the conductive layer and the metal cap is in direct contact with the second electrode above the pixel definition layer.

According to the OLED panel provided in the embodiments of the present disclosure, the second electrode layer on the light-emitting substrate is electrically connected, at each subpixel, to the conductive layer on the color filter substrate via the metal cap and then the elastic conductor route. As results, the total resistance of the second electrode, i.e. the cathode of the OLED, is reduced significantly, and the voltage drop on cathode and associated display image artifacts can be minimized to a level below what a human can conceive.

Hereinafter the present disclosure is further described in detail in conjunction with the drawings and embodiments. It is to be understood that the embodiments set forth below are intended to illustrate and not to limit the present disclosure. Additionally, it is to be noted that for ease of description, only part, not all, of the structures related to the present disclosure are illustrated in the drawings.

<FIG> depicts a plane view of an OLED panel according to embodiments of the present disclosure, its cross-sectional view is illustrated in <FIG> along a cross section A-A'. As shown in <FIG> and <FIG>, the OLED panel includes a light-emitting substrate <NUM> and a color filter substrate <NUM> disposed in parallel to the light-emitting substrate.

The light-emitting substrate <NUM> includes: a first substrate <NUM>, a first electrode layer <NUM>, a pixel definition layer <NUM>, a light-emitting layer <NUM> including a hole injection layer (not shown) and a second electrode layer <NUM>. The first electrode layer <NUM> includes a plurality of isolated first electrodes <NUM> and is disposed on the first substrate <NUM>. The pixel definition layer <NUM> is disposed on the first electrodes <NUM> and includes a plurality of first opening structures <NUM> to expose part of the first electrodes <NUM>. The hole transport layer, the light-emitting layer <NUM> and the second electrode layer <NUM> are successively disposed on the exposed first electrodes <NUM>.

The color filter substrate <NUM> includes: a second substrate <NUM>, a conductive layer <NUM>, a color filter layer <NUM>, a wall-shaped elastic conductor <NUM> wearing a metal cap <NUM>. The conductive layer <NUM> is disposed on a surface of the second substrate <NUM> facing towards the light-emitting substrate <NUM>. The color filter layer <NUM> is disposed on the same surface and overlapped on the conductive layer <NUM>. The color filter layer <NUM> includes a plurality of sub-pixel color filters <NUM> arranged in an array with a gap between each two adjacent sub-pixel color filters <NUM> that a portion of the conductive layer <NUM> is then exposed through the gap. The elastic conductor <NUM> is sitting on the conductive layer at the gaps, so as to have a same voltage as the conductive layer <NUM>. The metal cap <NUM> is disposed on the top of the wall-shaped elastic conductor <NUM> facing towards the light-emitting substrate <NUM>. In a cross-sectional view the vertical projection of the wall-shaped elastic conductor <NUM> on the first substrate <NUM> is overlapped with the vertical projection of the pixel definition layer <NUM> on the first substrate <NUM>.

In conjunction with <FIG> and <FIG>, the position corresponding to a first opening structure <NUM> is a sub-pixel region. In this region, the first electrode <NUM>, the light-emitting layer <NUM> and the second electrode layer <NUM> form a light-emitting element. The light-emitting layer <NUM> may include, for example, a film layer such as a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer and an electron injection layer. To achieve a high sub-pixel density in a display panel or manufacture a display panel on a tiny silicon chip, the light-emitting layer <NUM> including a hole injection layer of the light-emitting element is provided as an integral film layer, that is, the electron transport layer, the hole transport layer, the light-emitting layer, the electron injection layer and the hole injection layer of all light-emitting elements are not interrupted and each film layer in the light-emitting element cross pixel definition layers <NUM> between any two adjacent sub-pixels, thus avoiding the use of a plurality of masks to separately evaporate various layers of different light-emitting elements. Further, to prevent or reduce lateral charge diffusion or lateral crosstalk in the hole injection layer or the hole transport layer, a groove structure <NUM> may also be provided on the pixel definition layer <NUM> between two adjacent sub-pixels to increase the transmission path of the leakage current in the two adjacent sub-pixel regions in the film layer such as the hole injection layer, thereby blocking the lateral leakage current and further improving the display effect of the display panel.

It is to be noted that whether the groove structure <NUM> is provided at the pixel definition layer <NUM> is not limited in the embodiments of the present disclosure. The second electrode layer <NUM> crossing the pixel definition layer <NUM> is easy to break when the groove structure <NUM> is provided in the pixel definition layer <NUM>, so the solution provided by the embodiments of the present disclosure is also applicable to the case where the groove structure <NUM> is provided in the pixel definition layer <NUM>.

According to the embodiments of the present disclosure, the conductive layer <NUM>, the wall-shaped elastic conductor <NUM> wearing the metal cap <NUM> are configured in the color filter substrate <NUM>, and the second electrode layer <NUM> is electrically connected to the conductive layer <NUM> through the metal cap <NUM> and the wall-shaped elastic conductor <NUM>. In a cross-sectional view, a vertical projection of the wall-shaped elastic conductor <NUM> on the light-emitting substrate <NUM> completely covers a vertical projection of the groove structure <NUM> on the light-emitting substrate. The second electrode layer <NUM> on the light-emitting substrate <NUM> above the groove structure <NUM> and on both sides of the groove structure <NUM>)is reconnected to the conductive layer <NUM> via the metal cap and the wall-shaped elastic conductor <NUM>. On one hand, the problem that the resistance of the second electrode layer <NUM> is too large due to the thinner second electrode layer <NUM> can be solved. On the other hand, if the second electrode layer <NUM> is broken at the position of the pixel definition layer <NUM>, since the second electrode layer <NUM> can also be electrically connected to the conductive layer <NUM> sequentially through the metal cap <NUM> and the wall-shaped elastic conductor <NUM>, the voltage drop at the broken position of the second electrode layer <NUM> can also be avoided. In addition, the wall-shaped elastic conductor <NUM> has elasticity, and can provide support between the light-emitting substrate and the color filter substrate, absorb mechanical pressure during encapsulation of the light-emitting substrate <NUM> and the color filter substrate <NUM>, and maintain close contact of film layers in various regions to be maintained after the encapsulation. In addition, the metal cap <NUM> is deposited and grown on the wall-shaped elastic conductor <NUM>, so the metal cap <NUM> can be closely connected to the wall-shaped elastic conductor <NUM> to obtain reliable electrical connection at the atomic or molecular level. In addition, since the second electrode layer <NUM> is generally made of a metal material or a metal oxide material, the connection between the elastic conductor <NUM> and the second electrode layer <NUM> through the metal cap <NUM> can reduce relatively large contact resistance caused by different chemical and physical properties of the surfaces of the elastic conductor <NUM> and the second electrode layer <NUM>.

The conductive layer <NUM> may also extend to the non-display region of the color filter substrate <NUM> to form a second electrode connection pad so as to be conveniently connected to an external voltage control electrode on the underlying light-emitting substrate <NUM> during a subsequent bonding process.

According to the OLED panel provided in the embodiments of the present disclosure, the second electrode layer on the light-emitting substrate is electrically connected, at each subpixel, to the conductive layer on the color filter substrate via the metal cap and then the elastic conductor route. As results, the total resistance of the second electrode, i.e. the cathode of the OLED, is reduced significantly, and the voltage drop on cathode and associated display image artifacts can be minimized to a level below what a human can conceive. Since the wall-shaped elastic conductor has resilience, the wall-shaped elastic conductor at each position can also be in close contact with the second electrode layer through the metal cap, avoiding a gap between part of the second electrode layer at the region of the pixel definition layer and the color filter substrate caused by resonant cavity structures of different sub-pixels in the related art. In addition, the metal cap is deposited and grown on the wall-shaped elastic conductor, so the metal cap can be closely connected to the wall-shaped elastic conductor to obtain reliable electrical connection at the atomic or molecular level. Since the second electrode layer is generally made of a metal material or a metal oxide material, the connection between the wall-shaped elastic conductor and the second electrode layer through the metal cap can reduce the problem of relatively large contact resistance caused by different chemical and physical properties of the surfaces of the wall-shaped elastic conductor and the second electrode layer.

In one embodiment, the wall-shaped elastic conductor <NUM> includes an organic and conductive base material and an organic base material mixed with conductive particles.

The wall-shaped elastic conductor <NUM> is disposed between two adjacent sub-pixel color filters <NUM>, so that each pixel can be isolated into an independent closed or semi-closed space. An organic material has certain elasticity. The wall-shaped elastic conductor <NUM> is selected to include the organic and conductive base material, so that the wall-shaped elastic conductor <NUM> may have vertical elasticity in the direction perpendicular to the second substrate <NUM>, thus ensuring good resilience of the wall-shaped elastic conductor <NUM>. Further, the conductivity of the wall-shaped elastic conductor <NUM> can be improved by doping conductive ions in the wall-shaped elastic conductor <NUM>.

In one embodiment, the organic and conductive base material includes a poly ethylene material, a polyvinyl chloride material, a polystyrene material, a polypropylene material or a resin material.

In one embodiment, the organic material mixed with conductive particles includes at least one of following materials: a carbon nanoparticle, a carbon nanotube, a graphene particle, a silicon nanoparticle or a metal nanoparticle.

A high proportion of carbon nanoparticles, carbon nanotubes, graphene particles, silicon nanoparticles or metal nanoparticles are directly doped into the organic base material of the wall-shaped elastic conductor <NUM>, so that the conductivity of the wall-shaped elastic conductor <NUM> is further improved. Moreover, the doped material mixed with conductive particles can also reduce the light transmittance of the wall-shaped elastic conductor <NUM>, thus preventing the problem of light emission crosstalk in two adjacent sub-pixel regions.

In one embodiment, a volume ratio of the carbon nanoparticles or the carbon nanotubes in the wall-shaped elastic conductor <NUM> ranges from <NUM>% to <NUM>%.

Conductive particles are doped in the wall-shaped elastic conductor <NUM>, so that better conductivity and lower light transmittance of the wall-shaped elastic conductor <NUM> are realized. Amount of conductive particles mixed in the wall-shaped elastic conductor <NUM> will modulate the physical properties of the elastic conductor, that excessive amount of conductive particles will result in higher conductivity and less elasticity, while deficiency in conductive particles will lead to better elasticity but lower conductivity. It is found through analysis by the inventor, that a volume ratio of carbon nanoparticles or carbon nanotubes in the wall-shaped elastic conductor <NUM> ranging from <NUM>% to <NUM>% is preferred, considering a balance among the conductivity, light transmittance, elasticity and manufacturability. For example, <NUM>% to <NUM>% volume ratio of carbon nanoparticles in poly ethylene (PE), results a better conductivity and acceptable elasticity. If carbon nanotubes with better conductivity are adopted , the volume ratio of the doped carbon nanotubes can be reduced <NUM>% to <NUM>%, resulting better conductivity and elasticity of the wall-shaped elastic conductor.

It is to be noted that the organic and conductive base material includes a poly ethylene material, a polyvinyl chloride material, a polystyrene material, a polypropylene material or a resin material, and may be another organic material. The material of the organic and conductive base material is not specifically limited in the embodiments of the present disclosure. The conductive particles mixed in the base material include at least one of following materials: the carbon nanoparticle, the carbon nanotube, the graphene particle, the silicon nanoparticle and the metal nanoparticle, and the mixed conductive particles may be another particles having a conductive property. The property of the material mixed with conductive particles is not specifically limited in the embodiments of the present disclosure. In an actual design process, the balance between the resilience and conductivity of the wall-shaped elastic conductor may be comprehensively weighed, so that an appropriate organic and conductive base material may be selected, and the appropriate material and volume ratio of material mixed with conductive particles can be determined.

In one embodiment, the length of the carbon nanotube is less than <NUM> and the diameter of the carbon nanotube is less than <NUM>.

The thickness of the wall-shaped elastic conductor <NUM> is generally set between <NUM> micron and <NUM> microns, so after the volume ratio range of the carbon nanoparticles or carbon nanotubes in the wall-shaped elastic conductor <NUM> is selected, the length of the carbon nanotube is set to be less than <NUM> and the diameter of the carbon nanotube is set to be less than <NUM>, and thereby it is relatively easy to achieve a wall-shaped elastic conductor <NUM> with a low resistance value while satisfying the thickness of the wall-shaped elastic conductor <NUM>. Therefore, the manufactured wall-shaped elastic conductor <NUM> has better conductivity and resilience while having smaller resistance, avoiding the impact of too large resistance of the wall-shaped elastic conductor <NUM> on the electron transmission from the second electrode layer <NUM> to the wall-shaped elastic conductor <NUM>.

In one embodiment, the wall-shaped elastic conductor <NUM> includes a conducting macromolecule polymer.

Further, the wall-shaped elastic conductor <NUM> may be configured to include the conducting macromolecule polymer. The conducting macromolecule polymer is selected as the main material of the wall-shaped elastic conductor <NUM>, so that on one hand, the electrical connection between the conductive layer <NUM> and the metal cap <NUM> can be achieved by using the high conductivity of the material itself, and on the other hand, the potential conductive particle contamination existing in the manufacturing process of the wall-shaped elastic conductor <NUM> by using the etching process due to the doping of conductive particles such as carbon powder in the wall-shaped elastic conductor <NUM>.

In one embodiment, the wall-shaped elastic conductor <NUM> includes conducting macromolecule polyaniline, polyacetylene or polybutadiene.

The high molecular polymer material with relatively high conductivity, such as polyaniline, polyacetylene or polybutadiene, is adopted. In the molecular structure of the type of polyaniline, polyacetylene or polybutadiene, single bonds and double bonds are alternately arranged between carbon and carbon molecules: -CH=CH-, and π electrons in the double bonds of the carbon molecules are delocalized. The movement of π electrons along a conjugated chain forms the conductive mechanism of the high molecular polymer. The longer the molecular chain of the conjugated polymer, the greater the number of π electrons, the lower the activation energy of the electrons, and the better the conductivity.

In one embodiment, the wall-shaped elastic conductor <NUM> further includes at least one of the followings: carbon nanoparticle, carbon nanotube, graphene particle, silicon nanoparticle and metal nanoparticle.

When the wall-shaped elastic conductor <NUM> is made of a conducting macromolecule polymer, the conductivity of the wall-shaped elastic conductor <NUM> can be further improved by doping particles such as carbon nanoparticles, carbon nanotubes, graphene particles, silicon nanoparticles or metal nanoparticles into the wall-shaped elastic conductor <NUM>.

On the basis of the above solution, <FIG> shows a cross-sectional view of another OLED panel according to embodiments of the present disclosure. As shown in <FIG>, the OLED panel further includes a reflective layer <NUM>, and the reflective layer <NUM> is disposed on one sidewall of the wall-shaped elastic conductor <NUM>.

<FIG> exemplarily illustrates that the reflective layer <NUM> is disposed on the sidewall of the wall-shaped elastic conductor <NUM>. Since the reflective layer <NUM> is disposed on the sidewall of the wall-shaped elastic conductor <NUM>, the light emitted from each sub-pixel is limited in the closed space of the pixel, most of the light is directly emitted upward, part of the light with large angle reaches the reflective layer <NUM> on the sidewall of the wall-shaped elastic conductor <NUM> and is emitted after one or more reflections. Compared with the case of using an opaque wall-shaped elastic conductor <NUM>, the light absorbed by the sidewall of the pixel definition layer in this embodiment is negligible, and the loss of light in the sub-pixel is relatively small. That is, almost all the light emitted from the light-emitting element of each sub-pixel is reflected, and the light-emitting efficiency of the OLED panel is improved.

Further, <FIG> illustrates a sectional view of another OLEDOLED panel according to embodiments of the present disclosure, where the metal cap <NUM> extends to the sidewall of the wall-shaped elastic conductor <NUM> to form the reflective layer <NUM>.

The reflective layer <NUM> is formed by extension of the metal cap <NUM> to the wall-shaped elastic conductor <NUM>, so that on one hand, the metal cap <NUM> and the reflective layer <NUM> can be formed in one process, thereby avoiding the use of a plurality of masks to prepare the metal cap <NUM> and the reflective layer <NUM>, and reducing the complexity of the manufacturing process. On the other hand, due to the reflective layer <NUM>, the wall-shaped elastic conductor <NUM> itself does not need to absorb light leaking at a large angle, so more choices are provided for the material of the wall-shaped elastic conductor <NUM> and the conductive particles doped in material mixed, and the wall-shaped elastic conductor doped with conductive particles may be transparent or opaque.

In one embodiment, as shown in <FIG> and <FIG>, the reflective layer <NUM> is disposed on one side of the metal cap <NUM> facing towards or facing away from the light-emitting substrate <NUM>. <FIG> exemplarily illustrates that the reflective layer <NUM> is disposed on the side of the metal cap <NUM> facing towards the light-emitting substrate <NUM>, and <FIG> exemplarily illustrates that the reflective layer <NUM> is disposed on the side of the metal cap <NUM> facing away from the light-emitting substrate <NUM>.

In one embodiment, the working function difference between the reflective layer <NUM> and the metal cap <NUM> is less than <NUM> V.

Referring to <FIG> and <FIG>, the reflective layer may be disposed on the side of the metal cap facing towards the light-emitting substrate, or may be disposed on the side of the metal cap facing away from the light-emitting substrate. The working function difference between the reflective layer <NUM> and the metal cap <NUM> is set to be less than <NUM> V, so that it is possible to effectively prevent the metal cap <NUM> and the reflective layer <NUM> from having relatively large contact resistance due to the material difference therebetween.

In one embodiment, the conductive layer <NUM> includes chromium, chromium oxide or indium tin oxide.

The conductive layer <NUM> is disposed on the side of the wall-shaped elastic conductor <NUM> facing towards the second substrate <NUM>, the conductive structure <NUM> is located between adjacent sub-pixel color filters <NUM>, and the wall-shaped elastic conductor <NUM> is electrically connected to the conductive layer <NUM> through a gap between adjacent color filter of sub-pixels <NUM>. The material selected for the conductive layer <NUM> includes chromium, chromium oxide or indium tin oxide, which can ensure that the conductive layer <NUM> has relatively low reflectivity, prevent the visible reflection of ambient light, and improve the display effect of the display panel.

It is to be noted that the conductive layer <NUM> may also be another conductive material with low reflectivity. The material of the conductive layer <NUM> is not specifically limited in the embodiments of the present disclosure.

In one embodiment, the conductive layer <NUM> is in a grid shape; or the conductive layer <NUM> includes a plurality of parallel conductive strips <NUM>. <FIG> exemplarily illustrates that the conductive layer <NUM> is in a grid shape, and <FIG> exemplarily illustrates that the conductive structure <NUM> includes a plurality of parallel conductive strips <NUM>.

A plurality of sub-pixels are defined in the OLED panel by a plurality of scanning lines and a plurality of data lines, the conductive layer <NUM> is disposed on the scanning line and the data line between adjacent sub-pixels, and the conductive layer <NUM> is in a grid shape. In this way, the conductive layer <NUM> can block the scanning line and the data line between adjacent sub-pixels, avoiding light leakage between two adjacent sub-pixels, and improving the display effect of the display panel.

Further, the conductive layer <NUM> is configured to include a plurality of parallel conductive strips <NUM>. For example, the conductive layer <NUM> may be a plurality of conductive strips <NUM> parallel to the data lines of the display panel or a plurality of conductive strips <NUM> parallel to the scanning lines of the display panel. As shown in <FIG> exemplarily illustrates that the conductive layer <NUM> is a plurality of parallel conductive strips <NUM>. Through an increase in the thickness of the conductive strip, the material cost can be saved on the premise of ensuring the conductivity requirement of the conductive layer <NUM>, and the preparation process is simple.

Another embodiment is illustrated in <FIG>, which shows a cross-sectional view of the OLED panel illustrated in <FIG> along B-B' cross-section. As shown in <FIG>, the plurality of sub-pixel color filters <NUM> is arranged in an array, and in a direction parallel to an array row and/or in a direction parallel to an array column, the wall-shaped elastic conductor <NUM> includes a protrusion portion <NUM> and a recess portion <NUM> which are spaced apart.

As shown in <FIG>, the wall-shaped elastic conductor <NUM> includes a protrusion portion <NUM> and a recess portion <NUM>. When the light-emitting substrate <NUM> and the color filter substrate <NUM> in the OLED panel are bonded, lateral circulation of the internal airflow between the light-emitting substrate <NUM> and the color filter substrate <NUM> can be achieved. Furthermore, it is ensured that the wall-shaped elastic conductor <NUM> at each position can be in close contact with the second electrode layer <NUM> through the metal cap <NUM>, avoiding a gap between part of the second electrode layer <NUM> at the region of the pixel definition layer <NUM> and the color filter substrate <NUM> due to the resonant cavity structures of different sub-pixels the related art.

The color filter substrate further includes a planarization layer, and the planarization layer is disposed on the surface of the color filter layer facing towards the light-emitting substrate. First, a wall-shaped elastic conductor is formed in a manner of linear coating or spin coating at a place where the conductive layer is exposed between adjacent sub-pixel color filters, and includes a protrusion portion <NUM> and a recess portion <NUM>, and then a planarization layer is formed in a manner of coating. Since the formed wall-shaped elastic conductor <NUM> includes the protrusion portion and the recess portion, the wall-shaped elastic conductors formed on different pixel definition layers have different heights. The planarization layer is formed on the wall-shaped elastic conductor in the manner of coating, and the planarization layer in a liquid state before curing can flow laterally between adjacent sub-pixels through the protrusion portion and the recess portion, thus achieving the purpose of planarization of the uneven surface of the entire wall-shaped elastic conductor, and ensuring the close contact of the film layers in each region when the light-emitting substrate <NUM> and the color filter substrate <NUM> are mechanically press-fitted.

In one embodiment, still referring to <FIG>, D1 represents a thickness of the recess portion and D2 represents a thickness of the protrusion portion. In a direction in which the recess portion and the protrusion portion are spaced apart, L1 represents a length of the protrusion portion and L2 represents a length of the recess portion, where <NUM> ≤ D2/D1 ≤ <NUM>, and <NUM> ≤ L2/L1 ≤ <NUM>.

When the height difference between the recess portion <NUM> and the protrusion portion <NUM> of the wall-shaped elastic conductor <NUM> is set to be too large, it is easy to cause large-angle light in the current pixel to pass through the gap and enter the cavity of the adjacent sub-pixel, thus causing light crosstalk and color mixing. However, when the height difference between the recess portion <NUM> and the protrusion portion <NUM> of the wall-shaped elastic conductor <NUM> is set to be too small, the lateral circulation of the airflow inside the wall-shaped elastic conductor <NUM> will be affected and the obstruction of the lateral circulation of the airflow will be increased. Considering the difficulty in manufacturing process, the mechanical pressure during encapsulation of the light-emitting substrate and the color filter substrate, and the elasticity characteristic of the wall-shaped elastic conductor, the thickness D1 of the recess portion and the thickness D2 of the protrusion portion may be set to satisfy <NUM> ≤ D2/D1 ≤ <NUM>, and the length L1 of the protrusion portion and the length L2 of the recess portion may be set to satisfy <NUM> ≤ L2/L1 ≤ <NUM>.

On the basis of the above embodiment, <FIG> is a flowchart illustrating a manufacturing method of an OLED panel according to embodiments of the present disclosure. The method includes steps described below.

In S110, a first electrode layer, a pixel definition layer, a light-emitting layer and a second electrode layer are successively formed on a first substrate, the first electrode layer includes a plurality of first electrodes, the pixel definition layer includes a plurality of first opening structures to expose part of the first electrodes.

In S120, a conductive layer and a color filter layer are formed on a second substrate, the color filter layer includes a plurality of sub-pixel color filters, and a gap between two adjacent sub-pixel color filters that a portion of the conductive layer is exposed through the gap.

In S130, a wall-shaped elastic conductor and a metal cap are formed, where the wall-shaped elastic conductor is in contact with the conductive layer through the gap between the two adjacent sub-pixel color filters, and the metal cap is disposed on the top of the wall-shaped elastic conductor facing away from the second substrate.

In S140, the surface of the first substrate formed with the second electrode layer and the surface of the second substrate formed with the wall-shaped elastic conductor and the metal cap are press-fitted and encapsulated.

The manufacturing process of the light-emitting substrate includes the following step: the first electrode layer, the pixel definition layer, the light-emitting layer and the second electrode layer are successively formed on the first substrate, the first electrode layer includes the plurality of first electrodes, the pixel definition layer includes the plurality of first opening structures to expose part of the first electrodes.

The manufacturing process of the color filter substrate includes the following steps: first, a layer of conductive layer is deposited on the second substrate, where the material of the conductive layer includes chromium, chromium oxide, indium tin oxide, and the like, and then the light sensitive resin doped with red (R), green (G) and blue (B) dyes is used on the conductive layer to form pixel color filter arrays of three colors, i.e., R, G and B, respectively through three processes. Since the thickness of each pixel color filter layer is different, a planarization layer is formed in a manner of coating. The planarization film layer between adjacent sub-pixel color filters is provided with a hole to expose the conductive layer, and then a linear coating or spin coating manner is adopted at the place where the conductive layer is exposed between the adjacent sub-pixel color filters, for example, a wall-shaped elastic conductor with a thickness of not less than <NUM> micron is coated. After the coating process is completed, thermal bake or UV curing process is performed in an oven at no lower than <NUM>, or an organic film hardening process with equal emphasis on thermal bake and UV is performed. A metal film layer with high conductivity is plated on the hardened and formed wall-shaped elastic conductor in a manner of sputtering or thermal evaporation. A relatively stable high-conductivity material, such as gold, silver, copper or alloy, may be selected, or the same metal material as the second electrode layer may be directly used to perform photolithography on the metal film layer in a manner of photolithography to form a metal cap.

After the manufacturing processes of the light-emitting substrate and color filter substrate are respectively completed, the surface of the first substrate formed with the second electrode layer and the surface of the second substrate formed with the wall-shaped elastic conductor and the metal cap are press-fitted and encapsulated.

According to the manufacturing method of the OLED panel provided in the embodiments of the present disclosure, the first electrode layer, the pixel definition layer, the light-emitting layer and the second electrode layer are formed on the light-emitting substrate side, the conductive layer, the color filter layer, the wall-shaped elastic conductor and the metal cap are formed on the color filter substrate side, and then the side of the light-emitting substrate formed with the second electrode layer and the side of the color filter substrate formed with the wall-shaped elastic conductor and the metal cap are mechanically press-fitted and encapsulated. The second electrode layer on the light-emitting substrate is electrically connected to the conductive structure sequentially through the metal cap and the wall-shaped elastic conductor. Therefore, on one hand, the problem that the resistance of the second electrode layer is too large due to the thinner second electrode layer can be solved. On the other hand, if the second electrode layer is broken at the position of the pixel definition layer, since the second electrode layer can also be electrically connected to the conductive layer sequentially through the metal cap and the wall-shaped elastic conductor, the problem that light-emitting efficiency and light-emitting uniformity are affected due to an increase in the voltage drop at the broken position of the second electrode layer can also be avoided. In addition, since the wall-shaped elastic conductor has resilience, the wall-shaped elastic conductor at each position can also be in close contact with the second electrode layer through the metal cap, avoiding a gap between part of the second electrode layer at the region of the pixel definition layer and the color filter substrate due to the resonant cavity structures of different sub-pixels in the related art. Further, the metal cap is deposited and grown on the wall-shaped elastic conductor, so the metal cap can be closely connected to the wall-shaped elastic conductor to obtain reliable electrical connection at the atomic or molecular level. Since the second electrode layer is generally made of a metal material or a metal oxide material, the wall-shaped elastic conductor being connected to the second electrode layer through the metal cap can reduce the problem of relatively large contact resistance caused by different chemical and physical properties of the surfaces of the wall-shaped elastic conductor and the second electrode layer, improving light-emitting efficiency and light-emitting uniformity of the OLED panel.

In one embodiment, on the basis of the above embodiment, <FIG> is a flowchart illustrating another manufacturing method of an OLED panel according to embodiments of the present disclosure. The step of forming the wall-shaped elastic conductor and the metal cap includes steps described below.

In S210, a wall-shaped elastic conductor material layer is formed.

In S220, a metal cap material layer is formed on the side of the wall-shaped elastic conductor material layer facing away from the second substrate.

In S230, the metal cap material layer is etched to form a plurality of metal caps.

In S240, a plurality of wall-shaped elastic conductors are formed by using the metal cap or photoresist for etching the metal cap as a mask.

Claim 1:
An organic light-emitting display, OLED, panel, comprising a light-emitting substrate (<NUM>) and a color filter substrate (<NUM>) disposed in parallel to the light-emitting substrate (<NUM>); wherein
the light-emitting substrate (<NUM>) comprises: a first substrate (<NUM>), a first electrode layer (<NUM>) includes a plurality of first electrodes (<NUM>) and is disposed on the first substrate (<NUM>), a pixel definition layer (<NUM>) disposed on the first electrodes (<NUM>) and includes a plurality of first opening structures (<NUM>) defining sub-pixels and exposing part of the first electrodes (<NUM>), a light-emitting layer (<NUM>) including a hole injection layer and a second electrode layer (<NUM>) disposed on the first electrodes (<NUM>) and the pixel definition layer (<NUM>) and integrally formed between adjacent the first opening structures (<NUM>);
the color filter substrate (<NUM>) comprises: a second substrate (<NUM>), a color filter layer (<NUM>) formed by a plurality of sub-pixel color filters (<NUM>), a conductive layer (<NUM>) that is electrically connected to a wall-shaped elastic conductor (<NUM>) wearing a metal cap;
in a cross-sectional view, a vertical projection of the wall-shaped elastic conductor (<NUM>) on the first substrate (<NUM>) is overlapped with the vertical projection of the pixel definition layer (<NUM>) on the first substrate (<NUM>);
and the light-emitting substrate (<NUM>) and the color filter substrate (<NUM>) are laminated in a manner that the second electrode layer (<NUM>) on the light-emitting substrate (<NUM>) is electrically connected to the conductive layer (<NUM>) on the color filter substrate (<NUM>) via the metal cap and the wall-shaped elastic conductor (<NUM>);
wherein a groove structure (<NUM>) is provided on the pixel definition layer (<NUM>) between two adjacent sub-pixels to increase a transmission path of leakage current in the two adjacent sub-pixel regions for reducing lateral leakage current;
in a cross-sectional view, a vertical projection of the wall-shaped elastic conductor (<NUM>) on the light-emitting substrate (<NUM>) completely covers a vertical projection of the groove structure (<NUM>) on the light-emitting substate, and the second electrode layer (<NUM>) on the light-emitting substrate (<NUM>) above the groove structure (<NUM>) and on both sides of the groove structure (<NUM>) is reconnected to the conductive layer (<NUM>) via the metal cap and the wall-shaped elastic conductor (<NUM>).