Display panel and preparation method thereof

Abstract

The invention discloses a display panel and a preparation method thereof. The display panel comprises a substrate, a pixel definition layer and a lyophobic layer, the pixel definition layer is arranged on the substrate, the pixel definition layer comprises a dam and a pixel opening defined by the dam, and the dam comprises a side wall close to one side of the pixel opening; the lyophobic layer is arranged on the side wall of the dam; the side wall comprises a first sub-side wall and a second sub-side wall which are adjacent to each other, the first sub-side wall is arranged close to the substrate, the second sub-side wall is located on one side, deviating from the substrate, of the first sub-side wall, the lyophobic layer covers the second sub-side wall, and the lyophobic layer is connected with the second sub-side wall at least through a carbon-sulfur single bond. According to the display panel, the problem of device performance reduction caused by upward climbing of the ink material in the pixel opening can be effectively improved or avoided, so that the display quality of the display panel is improved, the manufacturing process difficulty of the lyophobic layer can be effectively reduced, and the manufacturing cost of the display panel is reduced.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a display panel and a method for manufacturing the same. Background Technology

[0002] Organic light-emitting diodes (OLEDs) have advantages such as fast response speed, high contrast and wide viewing angle, and are easy to realize flexible display, making them the mainstream product of the next generation of display technology.

[0003] OLED devices have an anode, an organic functional layer, and a cathode sequentially formed on a substrate. The organic functional layer typically includes a hole injection layer (HIL), a hole transport layer (HTL), an emitting layer (EML), an electron injection layer (EIL), and an electron transport layer (ETL). The hole injection layer, hole transport layer, emitting layer, and electron transport layer are sequentially formed within the pixel opening using inkjet printing (IJP). Due to limitations in ink materials and processing techniques, the edges of the hole injection layer, hole transport layer, and emitting layer may accumulate on the sidewalls of the "bank," forming a sloping structure. This can cause the printed film to form brown rings inside the pixel, reducing the uniformity of film thickness and thus degrading the performance of the OLED device. Furthermore, if the printed film slopes too high on the sidewalls of the bank, it may come into contact with other film layers, creating leakage paths and further degrading the OLED device's performance. Summary of the Invention

[0004] This application provides a display panel and its manufacturing method, which can effectively improve or avoid the problem of device performance degradation caused by ink material climbing up the pixel opening, thereby improving the display quality of the display panel. It can also effectively reduce the manufacturing difficulty of the hydrophobic layer, thereby reducing the manufacturing cost of the display panel.

[0005] To achieve the above objectives, according to a first aspect of this application, a display panel is provided, comprising: substrate; A pixel definition layer is disposed on the substrate; the pixel definition layer includes a dam and a pixel opening formed by the dam; the dam includes a sidewall near the pixel opening; and A liquefying layer is disposed on the sidewall of the dam; The sidewall includes a first sub-sidewall and a second sub-sidewall that are adjacent to each other. The first sub-sidewall is disposed close to the substrate, and the second sub-sidewall is located on the side of the first sub-sidewall that is away from the substrate. The hydrophobic layer covers the second sub-sidewall, and the hydrophobic layer and the second sub-sidewall are connected at least by carbon-sulfur single bonds.

[0006] Optionally, the material of the dam includes a first organic compound containing a thiol group, the first organic compound being free of fluorine, and the first organic compound being present in the dam at a mass percentage ranging from 1% to 10%.

[0007] Optionally, the first organic compound includes any one or more combinations of mercaptopropyltriethoxysilane, alkyl thiols, aromatic cyclothiols, silyl thiols, terpene thiols, mercaptostyrene, mercaptolactic acid, mercaptocaprolactone, mercaptoacrylates, mercapto-containing polystyrene, mercapto-containing polylactic acid, mercapto-containing polycaprolactone, and mercapto-containing acrylate polymers.

[0008] Optionally, the material of the hydrophobic layer includes a second organic compound containing terminal double bonds, the second organic compound being fluorine-free, and the terminal double bonds of the second organic compound forming carbon-sulfur single bonds with the thiol groups of the first organic compound through an addition reaction.

[0009] Optionally, the second organic compound further comprises any one or more of the following: a polysiloxane group having a long-chain alkyl group with more than 3 carbon atoms, a silane bond having a long hydrocarbon alkyl group with more than 3 carbon atoms, an acrylate group having a long hydrocarbon alkyl group with more than 3 carbon atoms, and a polysilsesquialkyl group.

[0010] Optionally, the second organic compound includes any one or more of the following: acryloyloxypropyl-terminated polydimethylsiloxane, tris(trimethylsiloxy)silylethyl acrylate, acrylate having a long-chain alkyl group with 12 or more carbon atoms, methacrylate having a long-chain alkyl group with 12 or more carbon atoms, isobornyl acrylate, α,ω-bis(meth)acryloyloxypropyl-terminated polydimethylsiloxane, mono-terminated (meth)acrylate-terminated polydimethylsiloxane, polyurethane acrylate oligomers, and methacryloyloxypropyl cage-type polysilsesquioxane.

[0011] Optionally, in the thickness direction of the substrate, the ratio of the height of the first sub-sidewall to the total height of the first sub-sidewall and the second sub-sidewall ranges from 0.1 to 0.2.

[0012] Optionally, the dam further includes a top surface connected to the second sub-sidewall on the side away from the substrate, wherein the second sub-sidewall is divided into a plurality of hydrophobic regions in a direction extending toward the top surface; The materials of the hydrophobic layers located within the same hydrophobic region are the same, while the materials of the hydrophobic layers located in different hydrophobic regions are different, and the hydrophobicity of the plurality of hydrophobic regions gradually increases in the direction extending from the second sub-sidewall toward the top surface.

[0013] Optionally, at least the dam in the region where the first sub-sidewall is located is hydrophilic.

[0014] According to a second aspect of this application, a method for manufacturing the above-described display panel is provided, comprising the following steps: A pixel definition layer is formed on one side of a substrate; the pixel definition layer includes a dam and a pixel opening formed by the dam, the dam including a sidewall near the pixel opening, the sidewall including a first sub-sidewall disposed near the substrate and a second sub-sidewall located on the side of the first sub-sidewall facing away from the substrate, and the material of the dam having thiol groups; A hydrophilic layer is formed on the second sub-sidewall, the material of which has terminal double bonds; and The lyophobic layer is subjected to photo-irradiation treatment so that the thiol groups react with the terminal double bonds to form carbon-sulfur single bonds.

[0015] The display panel and its fabrication method provided in this application utilize a hydrophobic layer formed on the second sub-sidewall of a dam, with the hydrophobic layer and the second sub-sidewall connected by carbon-sulfur (CS) single bonds. This hydrophobicity of the second sub-sidewall prevents ink material printed in the pixel opening from overflowing and also improves or prevents ink material from climbing up the sidewall of the dam. This avoids leakage caused by the film layer formed at the bottom of the pixel opening contacting other film layers, thus improving the display quality of the display panel. Furthermore, the carbon-sulfur (CS) single bond can be obtained through an addition reaction between a thiol group and a carbon-carbon double bond, allowing the hydrophobic layer to be directly prepared using coating or vapor deposition combined with photolithography. The distribution range of the hydrophobic layer can be adjusted using a photomask, effectively simplifying the fabrication process and reducing the manufacturing cost of the display panel while achieving hydrophobic properties.

[0016] Therefore, by setting a hydrophobic layer on the second sub-sidewall of the dam and connecting it to the second sub-sidewall via carbon-sulfur (CS) single bonds, this application can effectively improve or avoid the problem of device performance degradation caused by ink material climbing uphill in the pixel opening, thereby improving the display quality of the display panel and effectively reducing the manufacturing process difficulty of the hydrophobic layer, thus reducing the manufacturing cost of the display panel.

[0017] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0019] Figure 1 This is a schematic diagram of the structure of an exemplary OLED display panel provided in this application; Figure 2 This is a schematic diagram of the structure of a display panel provided in an embodiment of this application; Figure 3 This is a schematic diagram of the cross-sectional structure of a dam provided in an embodiment of this application; Figure 4 This is a top view of a dam structure provided in an embodiment of this application; Figure 5 This is a schematic flowchart of a method for manufacturing a display panel according to an embodiment of this application; Figure 6 This is a schematic diagram of the structure of a display device provided in an embodiment of this application. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0021] Typically, both the organic functional layer and the cathode metal layer in OLED devices are fabricated using a vacuum thermal evaporation process. However, the high cost of vacuum thermal evaporation limits the widespread commercialization of OLED displays. Compared to traditional vacuum thermal evaporation, inkjet printing (IJP) technology offers numerous advantages, including high material utilization, mild process conditions, and more uniform film formation, making it more promising for applications.

[0022] Specifically, IJP technology uses multiple nozzles to drop ink material (or ink) containing dissolved functional materials into predetermined pixel openings, and then obtains a thin film with the desired pattern through drying. On the substrate used in the IJP film deposition process, grooves are usually made to confine the ink material, allowing ink droplets to flow into the grooves. After drying and baking, the ink material shrinks within the confinement area of ​​the grooves to form a thin film.

[0023] Figure 1 This is a schematic diagram of an exemplary OLED display panel 1'. The OLED display panel 1' includes a substrate 2' and, sequentially disposed on the substrate 2', a first electrode layer (i.e., anode) 3', a pixel definition layer 4', a hole injection layer (HIL) 10a', a hole transport layer (HTL) 10b', a light-emitting layer (EML) 10c', an electron transport layer (ETL) 10d', an electron injection layer (EIL) 10e', and a second electrode layer (i.e., cathode) 11'. The pixel definition layer 4' includes a dam 5' and a pixel opening 6' formed by the dam 5', and the pixel opening 6' is aligned with the first electrode layer 3'. The hole injection layer 10a', the hole transport layer 10b', and the light-emitting layer 10c' are sequentially formed within the pixel opening 6' by inkjet printing. Due to the varying hydrophilicity of different ink materials, inks with higher hydrophilicity tend to have a higher creepage on the sidewall 7' of the dam 5', causing the printed film to form a coffee-colored ring within the pixel opening 6'. For example, the edges of the hole injection layer 10a', hole transport layer 10b', and light-emitting layer 10c' accumulate on the sidewall 7' of the dam 5', forming a creepage structure with consistent creepage height, making it impossible for the upper film layer to completely cover the edge of the lower film layer. Moreover, when the creepage of the bottom hole injection layer 10a' is high, the hole injection layer 10a' and the electron transport layer 10d' will overlap at the creepage point, forming a leakage path and causing a decrease in the performance of the OLED device.

[0024] To address the aforementioned issues, this application improves the structure of a display panel containing OLED devices. By providing a hydrophobic layer on the upper half of the sidewall of the dam in the pixel definition layer, and connecting the hydrophobic layer to the sidewall of the dam via carbon-sulfur single bonds, the portion of the dam covered with the hydrophobic layer exhibits strong hydrophobicity. This effectively confines the ink material within the pixel opening and effectively mitigates or prevents the ink material from climbing up the sidewall of the dam during film formation. This results in a film layer with a more uniform thickness, preventing the edge of the bottom hole injection layer from contacting other film layers above the light-emitting layer. Consequently, this improves or prevents leakage problems caused by ink material climbing up the dam.

[0025] like Figure 2 As shown, this application embodiment provides a display panel 1, which includes a substrate 2, a pixel definition layer 4 and a hydrophobic layer 9; the pixel definition layer 4 is disposed on the substrate 2, and the pixel definition layer 4 includes a dam 5 and a pixel opening 6 formed by the dam 5, and the dam 5 includes a sidewall 7 near the pixel opening 6; the hydrophobic layer 9 is disposed on the sidewall 7 of the dam 5.

[0026] The sidewall 7 includes a first sub-sidewall 7a and a second sub-sidewall 7b that are adjacent to each other. The first sub-sidewall 7a is disposed close to the substrate 2, and the second sub-sidewall 7b is located on the side of the first sub-sidewall 7a away from the substrate 2. The hydrophobic layer 9 covers the second sub-sidewall 7b, and the hydrophobic layer 9 and the second sub-sidewall 7b are connected at least by carbon-sulfur (CS) single bonds.

[0027] Understandably, the hydrophilic layer 9 does not cover the first sub-sidewall 7a; that is, the hydrophilic layer 9 is only provided on the upper half of the dam 5. Furthermore, the hydrophilic layer 9 has hydrophilic properties, such as hydrophobicity and / or oleophobicity.

[0028] In some embodiments, the display panel 1 further includes an organic functional layer 10 disposed in the pixel opening 6. The organic functional layer 10 is composed of a plurality of sub-film layers, and at least some of the sub-film layers in the organic functional layer 10 are formed by inkjet printing technology. During the inkjet printing process, ink material containing organic functional materials is dripped into the preset pixel opening 6 and at least contacts the first sub-sidewall 7a of the dam 5.

[0029] It should be noted that the above-mentioned hydrophobicity refers to the contact angle between the surface of the hydrophobic layer 9 and the ink material printed in the pixel opening 6 being greater than 90°.

[0030] In this embodiment, by providing a hydrophobic layer 9 on the second sub-sidewall 7b of the dam 5, and connecting the hydrophobic layer 9 to the second sub-sidewall 7b via carbon-sulfur (CS) single bonds, the second sub-sidewall 7b of the dam 5 becomes hydrophobic. This prevents ink material printed in the pixel opening 6 from overflowing and also improves or prevents ink material from climbing up the sidewall 7 of the dam 5, thus avoiding leakage caused by the film layer formed at the bottom of the pixel opening 6 contacting other film layers. This improves the display quality of the display panel 1. Furthermore, the carbon-sulfur (CS) single bond can be obtained through an addition reaction between a thiol group and a carbon-carbon double bond, allowing the hydrophobic layer 9 to be directly prepared by coating or vapor deposition combined with photolithography. The distribution range of the hydrophobic layer 9 can be adjusted using a photomask, effectively simplifying the preparation process of the hydrophobic layer 9 and reducing the manufacturing cost of the display panel 1 while achieving hydrophobic properties.

[0031] Therefore, by providing a hydrophobic layer 9 on the second sub-sidewall 7b of the dam 5, which is connected to the second sub-sidewall 7b by carbon-sulfur (CS) single bonds, this embodiment of the application can effectively improve or avoid the problem of device performance degradation caused by ink material climbing uphill in the pixel opening 6, thereby improving the display quality of the display panel 1 and effectively reducing the manufacturing process difficulty of the hydrophobic layer 9, thereby reducing the manufacturing cost of the display panel 1.

[0032] In some embodiments, the dam 5 further includes a top surface 8 connected to the side of the second sub-sidewall 7b away from the substrate 2, and the hydrophobic layer 9 extends from the second sub-sidewall 7b to the top surface 8. That is, the hydrophobic layer 9 also covers the top surface 8. This design can further prevent ink material printed in the pixel openings 6 from overflowing and avoid crosstalk between inks in adjacent pixel openings 6, which would affect the display effect.

[0033] In some embodiments, the material of the hydrophobic layer 9 does not contain fluorine.

[0034] Although fluorinated materials exhibit excellent hydrophobic properties, these properties rely on strong CF bonds. Most fluorinated materials decompose at high temperatures (above 260°C), releasing toxic gases such as hydrogen fluoride (HF). Furthermore, the recovery and degradation of fluorinated materials are difficult, leading to environmental accumulation, health risks, and disposal challenges. In addition, the availability of fluorine raw materials is difficult, purification costs are high, and the synthesis process of fluoropolymers is complex, resulting in fluorinated hydrophobic materials being significantly more expensive than traditional hydrophobic materials (such as silicon-based hydrophobic materials).

[0035] Currently, the scientific community is dedicated to developing low-toxicity, biodegradable fluorinated analogs or non-fluorinated alternatives to balance hydrophobic properties and environmental safety. The embodiments of this application, by setting a fluorine-free hydrophobic layer 9 on the dam 5, can effectively balance hydrophobic properties and environmental safety, while also reducing the manufacturing cost of the display panel 1.

[0036] In some embodiments, the display panel 1 further includes a first electrode layer 3 disposed between the substrate 2 and the organic functional layer 10, and a second electrode layer 11 disposed on the side of the organic functional layer 10 opposite to the first electrode layer 3.

[0037] In some embodiments, the pixel opening 6 is aligned with the first electrode layer 3, and at least a portion of the first electrode layer 3 is exposed in the pixel opening 6. The organic functional layer 10 includes a hole injection layer 10a, a hole transport layer 10b, a light-emitting layer 10c, an electron transport layer 10d, and an electron injection layer 10e sequentially disposed in the pixel opening 6. At least the hole injection layer 10a, the hole transport layer 10b, and the light-emitting layer 10c can be fabricated using an inkjet printing process.

[0038] In some embodiments, the first electrode layer 3 is an anode layer, the second electrode layer 11 is a cathode layer, and the second electrode layer 11 can cover the entire pixel definition layer 4 and the organic functional layer 10, but is not limited thereto.

[0039] Understandably, the first electrode layer 3, the organic functional layer 10, and the second electrode layer 11 constitute an OLED device.

[0040] In some embodiments, the substrate 2 includes a substrate layer 2a and a driving layer 2b disposed on the substrate layer 2a.

[0041] In some embodiments, the substrate 2a can be either a flexible substrate or a rigid substrate, and this application does not limit the type of substrate. When the substrate 2a is a flexible substrate, the material of the substrate 2a includes, but is not limited to, polyimide. When the substrate 2a is a rigid substrate, the material of the substrate 2a includes, but is not limited to, glass.

[0042] In some embodiments, the driving layer 2b includes multiple driving circuits for driving the OLED device to emit light. It is understood that the embodiments of this application do not limit the structure of the driving circuits.

[0043] In some embodiments, the first electrode layer 3 is disposed on the side of the driving layer 2b away from the substrate layer 2a, and the first electrode layer 3 is electrically connected to the driving circuit in the driving layer 2b.

[0044] In some embodiments, the first electrode layer 3 includes a plurality of anode units 12. The plurality of anode units 12 are electrically connected to a plurality of drive circuits in a one-to-one configuration.

[0045] In some embodiments, the pixel definition layer 4 is disposed on the side of the driving layer 2b opposite to the substrate layer 2a. Specifically, the number of pixel openings 6 in the pixel definition layer 4 is the same as the number of anode units 12 in the first electrode layer 3. Each pixel opening 6 is aligned with an anode unit 12, and at least a portion of the anode unit 12 is exposed in the corresponding pixel opening 6.

[0046] In some embodiments, the dam 5 covers the driving layer 2b and extends to the edge portion covering the anode unit 12, such that the anode unit 12 is partially exposed in the pixel opening 6, but is not limited thereto.

[0047] In some embodiments, the material of the dam 5 includes materials containing thiol groups ( The first organic compound of SH), the material of the liquefaction layer 9 includes those containing terminal double bonds (e.g. The first organic compound is a second organic compound containing CH=CH2. Neither the first nor the second organic compound contains fluorine, and the terminal double bond of the second organic compound reacts with the thiol group of the first organic compound to form a carbon-sulfur single bond through an addition reaction.

[0048] Understandably, the thiol group in the first organic compound is a terminal thiol group, that is... SH.

[0049] Specifically, the addition reaction formulas for the first and second organic compounds are shown below: R'—SH + H2C=CH—R” → R’—S—H2C—CH2—R”; In this context, R'—SH represents the first organic compound, H2C=CH—R” represents the second organic compound, R' and R” represent organic groups, and the conditions for the addition reaction are light irradiation (e.g., ultraviolet light) and a photoinitiator.

[0050] In some embodiments, the mass percentage of the first organic compound in the dam 5 ranges from 1% to 10%. For example, in the dam 5, the mass percentage of the first organic compound is a value between any two endpoints of 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, or more.

[0051] In this embodiment of the application, by adding the above-mentioned amount of the first organic compound to the dam 5, the first organic compound can be uniformly distributed inside the dam 5 and on the sidewall 7 without affecting the normal function of the dam 5. Thus, during the fabrication of the liquid-repellent layer 9, a liquid-repellent layer 9 of uniform thickness can be formed on the second sub-sidewall 7b of the dam 5. Furthermore, the terminal double bonds in the liquid-repellent layer 9 material and the thiol groups of a sufficient amount of the first organic compound form carbon-sulfur single bonds on the second sub-sidewall 7b of the dam 5 through an addition reaction, thereby strengthening the connection between the liquid-repellent layer 9 and the second sub-sidewall 7b of the dam 5.

[0052] It should be noted that the materials of dam 5 also include resin, solvent, monomer, initiator and other additives. These materials are conventional dam 5 materials. This application adds a first organic compound to the conventional dam 5 materials. Therefore, this application does not limit the specific materials of resin, solvent, monomer, initiator and other additives.

[0053] In some embodiments, the first organic compound includes any one or more combinations of mercaptopropyltriethoxysilane, alkyl thiols, aromatic cyclothiols, silane thiols, terpene thiols, mercaptostyrene, mercaptolactic acid, mercaptocaprolactone, mercaptoacrylates, mercapto-containing polystyrene (polystyrene-mercapto, PS-SH), mercapto-containing polylactic acid (polylactic acid-mercapto, PLA-SH), mercapto-containing polycaprolactone (polycaprolactone-mercapto, PCL-SH), and mercapto-containing acrylate polymers, but is not limited thereto.

[0054] Specifically, the first organic compound can be a small organic molecule or an organic polymer. Among them, small organic molecule compounds containing terminal thiol groups include the above-listed mercaptopropyltriethoxysilane, alkyl thiols, aromatic cyclothiols, silane thiols, mercaptoacrylates, mercaptostyrene, mercaptolactic acid, and mercaptocaprolactone. Organic polymers containing terminal thiol groups include the above-listed thiol-containing polystyrene, thiol-containing polylactic acid, thiol-containing polycaprolactone, and thiol-containing acrylate polymers.

[0055] Understandably, the molecular weight limit between small organic molecules and large organic molecules is 500. That is, the molecular weight of small organic molecules is less than 500, and the molecular weight of large organic molecules is greater than or equal to 500.

[0056] Specifically, mercaptopropyltriethoxysilanes include, but are not limited to, 3-mercaptopropyltriethoxysilane (MPTES).

[0057] Specifically, alkyl thiols include, but are not limited to, n-alkyl thiols, such as 1-hexanethiol, 1-octanethiol, 1-dodecathiol, 1-hexadecathiol, or 1-octadecathiol. Understandably, the longer the carbon chain of the alkyl group in an alkyl thiols, the stronger the liquefaction of the first organic compound.

[0058] Specifically, aromatic cyclothiols include, but are not limited to, thiophene, naphthiol or p-tert-butylbenzylthiol.

[0059] Specifically, silyl mercaptans include, but are not limited to, trimethylsilyl ethyl mercaptan.

[0060] Specifically, terpene thiols include, but are not limited to, α-terpinen thiols.

[0061] Specifically, mercaptostyrene includes, but is not limited to, p-mercaptostyrene or o-mercaptostyrene.

[0062] Specifically, mercaptolactic acid includes, but is not limited to, 2-mercaptopropionic acid-3-hydroxy or 3-mercaptolactic acid.

[0063] Specifically, mercaptocaprolactones include, but are not limited to, ε-4-mercaptocaprolactone or ε-3-mercaptocaprolactone.

[0064] Specifically, mercaptoacrylates include, but are not limited to, methyl mercaptomethacrylate, methyl mercaptoacrylate, or methyl mercaptoethyl acrylate.

[0065] Specifically, thiol-containing acrylate polymers include, but are not limited to, polymethyl methacrylate-thiol (PMMA-SH) or polybutyl acrylate-thiol (PBA-SH).

[0066] Understandably, polystyrene-thiol (PS-SH), polymethyl methacrylate-thiol (PMMA-SH), polybutyl acrylate-thiol (PBA-SH), polylactic acid-thiol (PLA-SH), and polycaprolactone-thiol (PCL-SH) are all thiol-functionalized polymers. The core of their design is the introduction of thiol groups (-SH) onto polymer molecules with different main chain structures, combining the inherent properties of the main chain polymer with the crosslinking reactivity of thiol groups. Furthermore, the thiol groups in these polymers can crosslink with resins containing double bonds (such as isobornyl acrylate and long-chain alkyl acrylates) through thiol-olefin addition reactions, forming a stable CS bond network, thereby improving the material's hydrophobicity, solvent resistance, and mechanical strength.

[0067] In some embodiments, the second organic compound further includes any one or more of the following: a polysiloxane group having a long-chain alkyl group having more than 3 carbon atoms, a silane bond having a long hydrocarbon alkyl group having more than 3 carbon atoms, an acrylate group having a long hydrocarbon alkyl group having more than 3 carbon atoms, and a polysilsesquialkyl group.

[0068] In some embodiments, the second organic compound includes any one or more of the following: acryloyloxypropyl-terminated polydimethylsiloxane, tris(trimethylsiloxy)silylethyl acrylate (TSA), acrylates having a long-chain alkyl group with 12 or more carbon atoms (referred to as long-chain alkyl acrylates), methacrylates having a long-chain alkyl group with 12 or more carbon atoms (referred to as long-chain alkyl (meth)acrylates), isobornyl acrylate, α,ω-bis(meth)acryloyloxypropyl-terminated polydimethylsiloxane, mono-terminated (meth)acrylate-terminated polydimethylsiloxane, polyurethane acrylate oligomers, and methacryloyloxypropyl cage-like polysilsesquioxane (Methacryloxypropyl POSS, MAPASS).

[0069] In some embodiments, the second organic compound includes, but is not limited to, a fluorine-free small organic molecule compound containing a terminal double bond that is hydrophobic or oleophobic, such as silicone acrylates, long-chain alkyl (meth) acrylates, isobornyl acrylate (IBOA).

[0070] Specifically, silicone acrylates include, but are not limited to, acryloxypropyl-terminated polydimethylsiloxanes, such as monomethacryloxypropyl-terminated polydimethylsiloxane (mPDMS) or tris(trimethylsiloxy)silylethyl acrylate (TSA).

[0071] Specifically, long-chain alkyl (meth)acrylates include lauryl methacrylate, hexadecyl methacrylate, and octadecyl methacrylate, but are not limited to these.

[0072] In some embodiments, the second organic compound includes, but is not limited to, a fluorine-free organic polymer containing terminal double bonds that is hydrophobic or oleophobic, such as a silicone terminal double bond polymer or a hydrophobic polyurethane acrylate oligomer.

[0073] Specifically, silicone-terminated double-bond polymers include, but are not limited to, α,ω-bis(meth)acryloyloxypropyl-terminated polydimethylsiloxanes and mono(meth)acrylate-terminated polydimethylsiloxanes.

[0074] Specifically, hydrophobic polyurethane acrylate oligomers include, but are not limited to, polybutadiene polyurethane acrylates.

[0075] In some embodiments, the ratio of the height of the first sub-sidewall 7a to the total height of the first sub-sidewall 7a and the second sub-sidewall 7b in the thickness direction of the substrate 2 ranges from 0.1 to 0.2. That is, the height of the first sub-sidewall 7a not covered by the hydrophobic layer 9 accounts for one-tenth to one-fifth of the total height of the sidewall 7 of the dam 5. This design allows for a larger distribution area of ​​the hydrophobic layer 9 on the sidewall 7 of the dam 5, thereby increasing the area of ​​hydrophobicity on the sidewall 7 of the dam 5. This helps reduce pinning points of the ink printed in the pixel opening 6, thereby improving the thickness uniformity of the organic functional layer 10 and avoiding leakage current problems caused by series connection between different film layers in the organic functional layer 10, thus improving the performance of the display panel 1.

[0076] In some embodiments, the thickness of the dam 5 ranges from 0.5 micrometers to 2.5 micrometers, with the specific thickness designed according to the thickness of the printed film layer.

[0077] In some embodiments, a double-layer or multi-layer sub-dam structure can be designed based on the slurry height and slurry degree on the sidewall 7 of the dam 5.

[0078] For example, the dam 5 includes a first sub-dam 5a and a second sub-dam 5b stacked on the substrate 2. The first sub-sidewall 7a is the sidewall 7 of the first sub-dam 5a near the pixel opening 6, and the second sub-sidewall 7b is the sidewall 7 of the second sub-dam 5b near the pixel opening 6. The first sub-sidewall 7a and the second sub-sidewall 7b are located on the same plane or curved surface. The first sub-dam 5a and the second sub-dam 5b can be manufactured independently or integrally formed.

[0079] In some embodiments, at least the dam 5 in the region where the first sub-sidewall 7a is located is hydrophilic.

[0080] In other words, when the dam 5 is composed of the first sub-dam 5a and the second sub-dam 5b, the first sub-sidewall 7a in the lower half is hydrophilic, while the second sub-sidewall 7b in the upper half, which has a hydrophobic layer 9, is hydrophobic. This design allows the second sub-sidewall 7b with the hydrophobic layer 9 of the second sub-dam 5b to be hydrophobic when printing ink material in the pixel opening 6, so as to prevent ink material from overflowing and preventing ink material from climbing up the sidewall 7 of the dam 5. The first sub-sidewall 7a of the first sub-dam 5a is hydrophilic so that the ink material can be fully spread, thereby obtaining an organic functional layer 10 (e.g., hole injection layer 10a) with uniform film thickness, improving or avoiding the risk of leakage caused by the edge of the organic functional layer 10 (e.g., hole injection layer 10a) climbing up the sidewall 7 of the dam 5.

[0081] In some embodiments, the first sub-dam 5a and the second sub-dam 5b are made of the same material, both of which are highly hydrophilic materials. For example, the material of dam 5 includes acrylic resin, phenolic resin, epoxy resin, etc., such as at least one of polymethyl methacrylate (PMMA) and polyhydroxystyrene (PHS).

[0082] like Figure 3 As shown, if it is necessary to design the hydrophobicity of the sidewall 7 of the dam 5 to exhibit a gradient distribution with the height of the sidewall 7, the number of layers of the second sub-dam 5b can be increased, and the material of the hydrophobic layer 9 on the surface of each second sub-dam 5b can be adjusted. It can be understood that when there are multiple layers of the second sub-dam 5b, the side of the multiple second sub-dams 5b closest to the pixel opening 6 is the second sub-sidewall 7b, and the side of the uppermost second sub-dam 5b facing away from the substrate 2 is the top surface 8.

[0083] For example, in the direction extending from the second sub-sidewall 7b toward the top surface 8, the second sub-sidewall 7b is divided into multiple hydrophobic regions 13. The hydrophobic layers 9 within the same hydrophobic region 13 are made of the same material, while the hydrophobic layers 9 in different hydrophobic regions 13 are made of different materials. In the direction extending from the second sub-sidewall 7b toward the top surface 8, the hydrophobicity of the multiple hydrophobic regions 13 gradually increases. This design allows the strength of the hydrophobicity of the hydrophobic surfaces on the second sub-sidewall 7b at different heights of the dam 5 to be adjusted according to the different hydrophilicities of the ink material to be printed, resulting in a relatively more uniform film thickness for each printed layer.

[0084] In some embodiments, when there are multiple layers of the second sub-dam 5b, the material of each second sub-dam 5b can be the same as that of the first sub-dam 5a, and the first sub-dam 5a and the multiple second sub-dams 5b can be integrally formed. This design can reduce the manufacturing difficulty of the dam 5, thereby saving manufacturing costs.

[0085] It is understandable that since the material of the dam 5 is hydrophilic, the second sub-sidewall 7b is also hydrophilic. However, since the second sub-sidewall 7b is provided with a hydrophobic layer 9, the hydrophobic surface formed by the hydrophobic layer 9 and the second sub-sidewall 7b is hydrophobic.

[0086] In some embodiments, the dam 5 can be fabricated using photolithography, and the dam 5 can be a linear dam, a matrix dam, or a circular dam, etc., which are not limited in this application.

[0087] It should be noted that matrix-type dikes are generally arranged in an array, consisting of multiple first and second dikes. The first and second dikes enclose multiple pixel openings. The first and second dikes are usually strip-shaped structures, extending along a specific direction and intersecting each other to form a matrix-like shape. Linear dikes are dikes set along the row or column direction. There are usually no dikes between pixel light-emitting units of the same color, but only linear dikes are set between pixel light-emitting units of different colors to separate them. Circular dikes are set around circular pixel openings, usually in a circular or near-circular annular structure, used to define circular sub-pixel regions.

[0088] For straight embankments, a liquid-repellent layer can be applied to the embankment along the row direction and / or along the column direction, depending on the properties of the ink material. In other words, a liquid-repellent layer can be applied to the sidewall of the embankment on any side, or on one or more sides, depending on the specific requirements.

[0089] Understandably, compared to linear dams, matrix dams can precisely define each sub-pixel area, effectively preventing the mixing of luminescent materials between adjacent pixels. This helps improve the independence of pixel luminescence and the accuracy of displayed colors, making them more suitable for inkjet printing processes, allowing ink to accurately drip into pixel pits to form organic functional layers.

[0090] like Figure 5 As shown, this application embodiment also provides a method for preparing the display panel described in the foregoing embodiment, the method including steps S501 to S503.

[0091] S501: A pixel definition layer is formed on one side of the substrate; the pixel definition layer includes a dam and a pixel opening formed by the dam, the dam includes a sidewall near the pixel opening, the sidewall includes a first sub-sidewall disposed near the substrate and a second sub-sidewall located on the side of the first sub-sidewall away from the substrate, and the material of the dam has thiol groups.

[0092] In some embodiments, the pixel definition layer is fabricated using photolithography, but is not limited thereto.

[0093] Specifically, the materials used for the dam are as described in the foregoing embodiments, and will not be repeated here. It is understood that the thiol group is located in the aforementioned first organic compound.

[0094] S502: A hydrophobic layer is formed on the second sub-sidewall, and the material of the hydrophobic layer has terminal double bonds.

[0095] In some embodiments, the hydrophobic layer is fabricated using a vapor deposition method, but is not limited thereto.

[0096] It is understood that the material of the lyophobic layer is as described in the foregoing embodiments and will not be repeated here. It is understood that the terminal double bond is located in the foregoing second organic compound.

[0097] S503: The lyophobic layer is phototreated to cause the thiol groups to react with the terminal double bonds to form carbon-sulfur single bonds.

[0098] In some embodiments, the lyophobic layer is phototreated with ultraviolet light (UV) to induce an addition reaction between the thiol group in the first organic compound and the terminal double bond in the second organic compound, forming a carbon-sulfur single bond.

[0099] Understandably, the thiol group reacts with the terminal double bond to form a carbon-sulfur single bond located on the second subsidence sidewall, that is, at the interface between the dam and the hydrophilic layer. Display panels prepared using this method include... Figure 2 As shown.

[0100] This application describes in detail the fabrication process of the dam and hydrophobic layer in two or more of the above-described display panels through Examples 1 and 2.

[0101] Example 1 The fabrication process of the aforementioned dam and hydrophobic layer in the display panel is as follows: Multiple first dams with a thickness of 0.5 micrometers and extending along a first direction are fabricated on a substrate on which a first electrode layer is formed using photolithography. Multiple second dams, each 0.8 micrometers thick and extending along a second direction, were fabricated on the basis of the first dam using photolithography. The first and second directions were perpendicular to each other, and 5% by mass of MPTES (i.e., the aforementioned first organic compound) was added to the second dams. A layer of MAPOSS was vapor-deposited onto the upper half of the second dam; and The second dam was irradiated with ultraviolet (UV) light, which caused MPTES and MAPOSS to undergo an addition reaction to form a hydrophobic film.

[0102] Understandably, MPTES undergoes an addition reaction with MAPOSS, which is the process of adding mercapto groups to carbon-carbon double bonds, thereby generating carbon-sulfur (CS) single bonds, so that the lyophobic layer and the upper part of the dam are connected at least through carbon-sulfur (CS) single bonds.

[0103] Specifically, such as Figure 4 As shown, the first dam 14 and the second dam 15 are arranged to intersect each other, for example, to be arranged perpendicular to each other.

[0104] Example 2 Another process for fabricating the aforementioned display panel's dams and microstructures is as follows: A matrix-shaped or circular dam with a thickness of 1.2 micrometers is fabricated on a substrate with a first electrode layer using photolithography; wherein, 10% by mass of mercaptoacrylate is added to the dam; A layer of MAPOSS is vapor-deposited onto the upper part of the dam; and The dam was irradiated with UV light to induce an addition reaction between mercaptoacrylate and MAPOSS, forming a hydrophobic layer.

[0105] Understandably, thioacrylate undergoes an addition reaction with MAPOSS, which is the process of thiol group adding to carbon-carbon double bond, thereby generating carbon-sulfur (CS) single bond, so that the lyophobic layer and the upper part of the dam are connected at least through carbon-sulfur (CS) single bond.

[0106] It should be noted that in Examples 1 and 2, the distribution range of the liquefaction layer on the sidewall of the dam is limited according to the film thickness of the cavitation injection layer.

[0107] In the pixel opening 6 enclosed by the dam 5 prepared in Examples 1 and 2, the hole injection layer 10a, hole transport layer 10b, and light-emitting layer 10c prepared by inkjet printing technology are as follows: Figure 2 As shown. Comparison Figure 1 and Figure 2 It is understood that by providing a hydrophobic layer 9 on the upper half of the surface of the dam 5, this application can effectively prevent the edges of the hole injection layer 10a and the hole transport layer 10b from climbing up along the side wall 7 of the dam 5 to contact the edge of the light-emitting layer 10c. This can effectively improve or prevent the formation of leakage paths, thereby effectively improving or preventing leakage problems caused by ink material climbing, and thus improving the display quality of the display panel 1.

[0108] As shown in Figure 6, this application embodiment also provides a display device 16, which includes the display panel 1 described in the foregoing embodiment.

[0109] In some embodiments, the display panel 1 further includes an encapsulation layer 17 covering the second electrode layer 11. The encapsulation layer 17 may be a thin film encapsulation layer 17, but is not limited thereto.

[0110] In some embodiments, the display device 16 further includes a touch layer 18 disposed on the light-emitting side of the display panel 1 and a protective layer 19 disposed on the side of the touch layer 18 facing away from the display panel 1, wherein the protective layer 19 includes, but is not limited to, ultra-thin glass.

[0111] In some embodiments, the display device 16 further includes a housing 20 disposed on the back and sides of the display panel 1 for protecting the display panel 1.

[0112] In this embodiment, by providing a fluorine-free hydrophobic layer 9 on the second sub-sidewall 7b of the dam 5, the hydrophobic performance and environmental safety can be effectively balanced, effectively improving or avoiding leakage problems caused by ink material climbing upwards, thereby improving the display quality of the display device 16.

[0113] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0114] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0115] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0116] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A display panel, characterized in that, include: substrate; A pixel definition layer is disposed on the substrate; The pixel definition layer includes a dam and pixel openings formed by the dam; The dam includes a sidewall near the pixel opening; as well as A liquefying layer is disposed on the sidewall of the dam; The sidewall includes a first sub-sidewall and a second sub-sidewall that are adjacent to each other. The first sub-sidewall is disposed close to the substrate, and the second sub-sidewall is located on the side of the first sub-sidewall that is away from the substrate. The hydrophobic layer covers the second sub-sidewall, and the hydrophobic layer and the second sub-sidewall are connected at least by carbon-sulfur single bonds.

2. The display panel according to claim 1, characterized in that, The material of the dam includes a first organic compound containing thiol groups, the first organic compound being free of fluorine, and the first organic compound having a mass fraction in the dam ranging from 1% to 10%.

3. The display panel according to claim 2, characterized in that, The first organic compound includes any one or more combinations of mercaptopropyltriethoxysilane, alkyl thiols, aromatic cyclothiols, silyl thiols, terpene thiols, mercaptostyrene, mercaptolactic acid, mercaptocaprolactone, mercaptoacrylate, mercapto-containing polystyrene, mercapto-containing polylactic acid, mercapto-containing polycaprolactone, and mercapto-containing acrylate polymers.

4. The display panel according to claim 2, characterized in that, The material of the hydrophobic layer includes a second organic compound containing terminal double bonds, the second organic compound being fluorine-free, and the terminal double bonds of the second organic compound forming carbon-sulfur single bonds with the thiol groups of the first organic compound through an addition reaction.

5. The display panel according to claim 4, characterized in that, The second organic compound further contains any one or more of the following: a polysiloxane group having a long-chain alkyl group with more than 3 carbon atoms, a silane bond having a long hydrocarbon alkyl group with more than 3 carbon atoms, an acrylate group having a long hydrocarbon alkyl group with more than 3 carbon atoms, and a polysilsesquialkyl group.

6. The display panel according to claim 5, characterized in that, The second organic compound includes any one or more of the following: acryloyloxypropyl-terminated polydimethylsiloxane, tris(trimethylsiloxy)silylethyl acrylate, acrylate having a long-chain alkyl group with 12 or more carbon atoms, methacrylate having a long-chain alkyl group with 12 or more carbon atoms, isobornyl acrylate, α,ω-bis(meth)acryloyloxypropyl-terminated polydimethylsiloxane, mono-terminated (meth)acrylate-terminated polydimethylsiloxane, polyurethane acrylate oligomers, and methacryloyloxypropyl cage-type polysilsesquioxane.

7. The display panel according to any one of claims 1 to 6, characterized in that, In the thickness direction of the substrate, the ratio of the height of the first sub-sidewall to the total height of the first sub-sidewall and the second sub-sidewall ranges from 0.1 to 0.

2.

8. The display panel according to claim 7, characterized in that, The dam also includes a top surface connected to the second sub-sidewall on the side away from the substrate, and the second sub-sidewall is divided into a plurality of hydrophobic regions in the direction in which the second sub-sidewall extends toward the top surface; The materials of the hydrophobic layers located within the same hydrophobic region are the same, while the materials of the hydrophobic layers located in different hydrophobic regions are different, and the hydrophobicity of the multiple hydrophobic regions gradually increases in the direction extending from the second sub-sidewall toward the top surface.

9. The display panel according to claim 1, characterized in that, At least the dam in the region where the first sub-sidewall is located is hydrophilic.

10. A method for manufacturing a display panel as described in any one of claims 1 to 9, characterized in that, Includes the following steps: A pixel definition layer is formed on one side of a substrate; the pixel definition layer includes a dam and a pixel opening formed by the dam, the dam including a sidewall near the pixel opening, the sidewall including a first sub-sidewall disposed near the substrate and a second sub-sidewall located on the side of the first sub-sidewall facing away from the substrate, and the material of the dam having thiol groups; A hydrophobic layer is formed on the second sub-sidewall, the material of which has terminal double bonds; as well as The lyophobic layer is subjected to photo-irradiation treatment so that the thiol groups react with the terminal double bonds to form carbon-sulfur single bonds.

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