Patent Application
20240057389
The present disclosure relates to a field of display technology, and particularly to a display panel and a manufacturing method of the display panel.
Manufacturing methods of light-emitting functional layers of organic light emitting diode (OLED) display devices generally include two types of vacuum thermal evaporation and ink-jet printing (IJP). Among them, in a preparation of the organic functional layers of the OLED display devices, UP technology has many advantages such as material saving, mild process conditions, and more uniform film formation compared with traditional vacuum thermal evaporation, so it has more application potential.
The UP technology directly drips the ink dissolved with OLED materials into a pre-made pixel definition layer and form a desired pattern after the solvent is volatilized. The pixel definition layer includes dams and a plurality of printing grooves arranged in an array surrounded by the dams, the printing grooves are used to limit the ink, and after drying and baking, the ink limited in the printing grooves forms a thin film.
However, as resolutions of display panels increase, pixels are designed to be smaller and smaller, which corresponds to higher and higher precision requirements of the inkjet printing, and printing precision and ink droplet volume are more and more difficult to control. During a process of the inkjet printing, various external factors, such as deterioration of nozzle stability, may lead to a phenomenon that an ink volume in the printing groove is too large, thus causing the ink in two adjacent printing grooves to be bridged on the dams, which in turn causes mura of the display device.
The present disclosure provides a new display panel and a manufacturing method of the display panel, so as to prevent bridging on dams of the ink in two adjacent printing grooves during a manufacturing process.
Technical solutions provided by the present disclosure are as follows:
A display panel, wherein the display panel includes:
A manufacturing method of a display panel, including:
Beneficial effects of the present disclosure are: in the display panel and the manufacturing method of the display panel provided by the present disclosure, diversion grooves passing through with each other are defined on the dams, when an ink volume in a single printing groove is too large and the ink overflows on the dams, the ink will flow into the diversion grooves, that is, the overflowing ink will be diverted away by the diversion grooves, and will not overflow into the adjacent printing grooves, so as to prevent two different inks in the adjacent printing grooves from bridging and causing poor display.
In order to explain technical solutions in embodiments of the present disclosure more clearly, the following will introduce briefly the drawings used in the description of the embodiments of the present disclosure. Obviously, the drawings in the following description are merely several embodiments of the present disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.
Description of reference numbers and/or reference letters in the drawings is as follows:
The technical solutions in the embodiments of the present disclosure will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, but not all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative work fall into protection scope of the present disclosure. Additionally, it should be understood that the specific embodiments described here are merely intended to illustrate and interpret the invention and are not intended to limit the invention. In the present disclosure, without contrary statement, orientational terms such as “up” and “down” are normally used to refer to up and down of the device in actual use or operation, specifically the orientations shown in the drawings; and “inside” and “outside” refer to contours of the device.
The specific embodiments of the display panel provided by the present disclosure will be described below.
Referring to
The light-emitting structural layer 20 includes a first electrode layer 21, a pixel definition layer 22, a light-emitting functional layer 23, and a second electrode layer 24. The pixel definition layer 22 is disposed on a side of the substrate 10 and includes a plurality of intersecting dams 220, and a plurality of printing grooves 221 arranged in an array are defined and surround by the dams 220. The light-emitting functional layer 23 is disposed in the printing grooves 221 to form a plurality of sub-pixel units. The first electrode layer 21 is disposed between the light-emitting functional layer 23 and the substrate 10, that is, the pixel definition layer 22 is disposed on the substrate 10 and the first electrode layer 21, the printing grooves 221 correspond to the first electrode layer 21, and the light-emitting functional layer 23 is disposed on the first electrode layer 21. Specifically, the first electrode layer 21 is disposed on a side of the driving circuit layer 12 facing away from the base layer 11, and the pixel definition layer 22 is disposed on sides of the driving circuit layer 12 and the first electrode layer 21 facing away from the base layer 11. Specifically, the first electrode layer 21 is an anode layer, and the second electrode layer 24 is a cathode layer.
A specific structure (not shown in figures) of the driving circuit layer 12 may adopt a structure in the prior art, at least including a gate metal layer, a gate insulating layer, a source-drain metal layer, and an interlayer insulating layer. The first electrode layer 21 is disposed on the interlayer insulating layer and is electrically connected to the source-drain metal layer. The driving circuit layer 12 merely needs to be able to satisfy its basic functions, and a positional relationship of its specific structure will not be repeated here. It can be understood that, in other embodiments, according to actual requirements, the specific structure of the driving circuit layer 12 may further include other functional layers other than the above, which are not limited here.
A material of the light-emitting functional layer 23 is a printing ink added with light-emitting functional materials, and the printing ink is dropped into the printing grooves 221 through the UP technology, and after a solvent evaporates, sub-pixels of a desired light-emitting functional layer 23 are formed.
At least one diversion groove 222 is defined on each of the dams 220. The diversion groove 222 includes an opening on a side surface of the dam 220 facing away from the substrate 10, that is, the diversion groove 222 is recessed inwardly from a side surface (i.e., a platform surface of the dam 220) of a corresponding one of the dams 220 facing away from the substrate 10. For convenience of subsequent descriptions, it is defined that the side surface of the dam 220 facing away from the substrate 10 is the platform surface 2200. At a same time, an extension direction of the diversion groove 222 is same as an extension direction of the corresponding one of the dams 220, and a plurality of the diversion grooves 222 pass through at intersections, thereby forming a whole through network, which facilitates drainage of overflowing ink when the light-emitting functional layer 23 is printed.
Specifically, the present disclosure does not limit a quantity of the diversion grooves 222 provided on each of the dams 220, which may be one as shown in
Specifically, the present disclosure does not limit a cross-sectional shape of the diversion groove 222, which may be an inverted trapezoid as shown in
Specifically, in a plane perpendicular to a thickness direction of the display panel 100, as shown in
Specifically, a depth of the diversion groove 222 is less than a depth of the printing groove 221, that is, the diversion groove 222 does not penetrate the dam 220, so, during a process of drying the ink, because the ink in the diversion groove 222 is not in contact with the first electrode layer 21 and does not emit light by itself, the ink drying in the diversion groove 222 does not affect a display of the panel. Preferably, in the thickness direction of the display panel 100, a distance between a bottom of the diversion groove 222 and the first electrode 21 is greater than 100 nm.
In the display panel 100 of the present disclosure, the diversion grooves 222 passing through with each other are defined on the dams 220, when the ink volume in a single printing groove 221 is too large and the ink overflows on the dams 220, the ink will flow into the diversion grooves 222, that is, the overflowing ink will be diverted away by the diversion grooves 222, and will not overflow into the adjacent printing grooves 221, so as to prevent two different inks in the adjacent printing grooves 221 from bridging and causing poor display.
Preferably, in some embodiments, the side surface of the dam 220 facing away from the substrate 10, that is, the platform surface 2200, may be a flat surface, or may be a convex arched surface facing away from the substrate 10, as shown in
Specifically, each of the dams 220 includes a first subsection 2201 and a second subsection 2202 separated by the diversion groove 222. A side surface of the first subsection 2201 facing away from the substrate 10 is a flat surface or a convex arched surface facing away from the substrate 10, and a side surface of the second subsection 2202 facing away from the substrate 10 is a flat surface or a convex arched surface facing away from the substrate 10. Understandably, when the side surfaces of the dams 220 facing away from the substrate 10 are flat, it is beneficial to manufacturing design and can save manufacturing processes compared to an arch design; when the side surfaces of the dams 220 facing away from the substrate 10 are convex arched surfaces facing away from the substrate 10, due to a design of the arched surfaces, when the ink in the printing grooves 221 overflows, a design of climbing and descending slopes increases difficulty of the ink overflowing and ease of the ink flowing into the diversion grooves 222 after overflowing, thereby improving a bad phenomenon of ink bridging to a certain extent.
Specifically, a distance between a vertex of a side of the first subsection 2201 of the dam 220 facing away from the substrate 10 and the substrate 10 and a distance between a vertex of a side of the second subsection 2202 of the dam 220 facing away from the substrate 10 and the substrate 10 may be the same, as shown in
It can be understood that
Referring to
It is well known that in the OLED display devices in prior art, the ink used in the inkjet printing is organic materials dissolved in a solvent of lipids or alcohols, and it has two properties: water-based and oil-based, and during the manufacturing process, the ink needs to be dried, and the dried ink should spread evenly on the substrate 10. A material that is hydrophilic means the ink can have a smaller contact angle on the material and is easy to level; a material that is hydrophobic means the ink will have a large contact angle on the material and is not easy to spread. Therefore, only a hydrophilic material can make the ink dry on the material to maintain a film with a uniform thickness. When the ink dries on a hydrophobic material, protrusions will be formed, which will seriously affect a uniformity of the film thickness.
In the embodiment, a surface of the first annular sidewall 2211 of the printing groove 221 close to the substrate 10 is hydrophilic, so that the printing ink can be quickly spread in the printing groove 221, and it is beneficial to maintain the uniformity of the film thickness after drying. At a same time, in the embodiment, a surface of the second annular sidewall 2212 of the printing groove 221 away from of the substrate 10 is hydrophobic, so that an accumulation effect of the printing ink in the printing groove 221 is enhanced, and the bad phenomenon of the ink bridging is improved to a certain extent.
Preferably, in some embodiments, the surfaces (i.e., the platform surfaces 2200) of the dams 220 facing away from the substrate 10 have hydrophobicity. That is, materials of the surfaces of the dams 220 facing away from the substrate 10 are hydrophobic materials. In this way, when the ink in the printing grooves 221 overflows, the ink has large contact angles with the surfaces of the dams 220 facing away from the substrate 10, so it will not overflow quickly, thereby preventing the overflowing ink from overflowing into the adjacent printing grooves 221 due to too fast flow rate, which improves the bad phenomenon of ink bridging to a certain extent.
Preferably, in some embodiments, inner wall surfaces 2221 and inner bottom surfaces 2222 of the diversion grooves 222 are all hydrophilic. That is, surface materials of the inner walls and the inner bottoms of the diversion grooves 222 are both hydrophilic materials. It is designed in this way that when the ink in the printing grooves 221 overflows, the ink overflows the surfaces of the dams 220 facing away from the substrate 10, and then flows instantaneously and smoothly in the diversion grooves 222, to prevent the overflowing ink from overflowing into the adjacent printing grooves 221, which further improves the bad phenomenon of the ink bridging.
In order to realize the above-mentioned hydrophilic and hydrophobic design, in an embodiment, the dams 220 are made of a hydrophilic photoresist material. The hydrophilic photoresist material is formed by mixing a resin, a sensitizer, and a solvent, and hydrophilic groups are added into the resin. The hydrophilic groups here can be ether bonds composed of oxygen-containing groups, hydroxyl groups and carboxylate esters, block polyethers, etc., which are not specifically limited, as long as basic functions can be satisfied. In addition, during the manufacturing process, in order to realize a hydrophobic design of the surface of the second annular sidewall 2212, the second annular sidewall 2212 is subjected to a plasma surface treatment containing fluorine ions or fluorine groups. The plasma containing fluorine ions or fluorine groups will bombard the surface of the photoresist material during the plasma surface treatment. At this time, the old bonds will break and new bonds will be formed on the photoresist surface, which will allow the fluorine groups or the fluorine ions to form bonding energy with the photoresist. In this way, the surface of the second annular sidewall 2212 has the fluoride ions or the fluorine groups, and exhibits hydrophobic and oleophobic properties, that is, hydrophobic properties.
It can be understood that, in other embodiments, the dams 220 can also be made of other alternative materials, as long as final requirements can be met. Similarly, the material of the dams 220 can also be made of hydrophobic materials, and then part of the surfaces can be made hydrophilic through a surface treatment, which is also within the scope of protection of the present disclosure.
Referring to
Specifically:
Referring to
Referring to
Specifically, a specific structure (not shown in figures) of the driving circuit layer 12 may adopt a structure in the prior art, at least including a gate metal layer, a gate insulating layer, a source-drain metal layer, and an interlayer insulating layer. The first electrode layer 21 is disposed on the interlayer insulating layer and is electrically connected to the source-drain metal layer. The driving circuit layer 12 merely needs to be able to satisfy its basic functions, and the positional relationship of its specific structure is not repeated here. It can be understood that, in other embodiments, according to actual requirements, the specific structure of the driving circuit layer 12 may further include other functional layers other than the above, which are not limited here.
Referring to
Specifically, before the photoetching process, according to the manufacturing process and actual demands, it is necessary to design a quantity, structures, and sizes of the dams 220, the printing grooves 221, and the diversion grooves 222 in advance. After the photoetching process is completed, the quantity, the structures, and the sizes of the dams 220, the printing grooves 221, and the diversion grooves 222 are same as the structures in the display panel 100 described above and will not be repeated here.
Referring to
Specifically, during the manufacturing process, the printing ink (Ink) is firstly dripped into the printing grooves 221 by using the UP technology, and during the dripping process, the printing ink (Ink) that overflows the printing grooves 221 flows into the diversion grooves 222, as shown in
Referring to
It is well known that, in the OLED display devices in prior art, the ink used in the inkjet printing is that organic materials dissolved in a solvent of lipids or alcohols, and there are two properties of water-based and oily, and during the manufacturing process, the ink needs to be dried, and the dried ink should be spread evenly on the substrate 10. That a material is hydrophilic means the ink can have a smaller contact angle on the material and is easy to level; That a material is hydrophobic means the ink will have a large contact angle on the material and is not easy to spread. Therefore, only a hydrophilic material can make the ink dry on the material to maintain a film with a uniformity thickness. When the ink dries on a hydrophobic material, protrusions will be formed, which will seriously affect a uniformity of the film thickness.
Therefore, in the embodiment, the first photoresist P1 is made of a hydrophilic photoresist material. Thus, a surface of the first annular sidewall 2211 of the printing groove 221 close to the substrate 10 is hydrophilic, so that the printing ink can be quickly spread in the printing grooves 221, and it is beneficial to maintain the uniformity of the film thickness after drying. At a same time, in the embodiment, inner side surfaces 2221 and inner bottom surfaces 2222 of the diversion grooves 222 are all hydrophilic. When the ink in the printing grooves 221 overflows, the ink overflows the surfaces of the dams 220 facings away from the substrate 10 and is then instantly leveled in the diversion grooves 222 to prevent the overflowing ink from overflowing into the adjacent printing grooves 221, which further improves the bad phenomenon of the ink bridging.
Understandably, in order to further improve the undesirable phenomenon of the ink bridging, the present embodiment also includes steps after the step S3 and before the step S4:
The processes of above-mentioned step S301 to step S304 are carried out before the step S4 of the inkjet printing, which makes the surfaces of the second annular sidewalls 2212 of the printing grooves 221 away from of the substrate 10 hydrophobic after the surface treatment. It enhances an accumulation effect of the printing ink in the printing grooves 221 and improves the bad phenomenon of the ink bridging to a certain extent. At a same time, the side surfaces (i.e., the platform surface 2200) of the dams 220 facing away from the substrate 10 are also hydrophobic after the surface treatment. When the ink in the printing grooves 221 overflows, the ink has a large contact angle with the side surfaces of the dams 220 facing away from the substrate 10, so it will not overflow quickly, thereby preventing the overflowing ink from overflowing into the adjacent printing grooves 221 due to the too fast flow rate, which improves the bad phenomenon of the ink bridging to a certain extent.
It can be understood that, in other embodiments, the dams 220 can also be made of other alternative materials, as long as the final requirements can be met. Similarly, the material of the dams 220 can also be made of hydrophobic materials, and then part of the surfaces can be made hydrophilic through a surface treatment, which is also within the scope of protection of the present disclosure.
In summary, although the present disclosure has been disclosed as above in preferred embodiments, the above-mentioned preferred embodiments are not intended to limit the present disclosure. Those of ordinary skills in the art, without departing from the spirit and scope of the present disclosure, various changes and modifications can be made, so the protection scope of the present disclosure is subject to the scope defined by the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202210145844.X | Feb 2022 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2022/077885 | 2/25/2022 | WO |
