Manufacturing method of display substrate, display substrate and display device

Provided are a manufacturing method of a display substrate, a display substrate and a display device, which belongs to the field of display technologies. The manufacturing method of the display substrate includes: forming a first planarization layer on a base substrate on which a patterned film layer is formed; forming a first buffer layer on the side, away from the base substrate, of the first planarization layer; forming a second buffer layer on the side, away from the base substrate, of the first buffer layer; and forming a Wire Grid Polarizer (WGP) on the side, away from the base substrate, of the second buffer layer.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Chinese Patent Application No. 201810834939.6 filed on Jul. 26, 2018 and entitled “MANUFACTURING METHOD OF DISPLAY SUBSTRATE, DISPLAY SUBSTRATE AND DISPLAY DEVICE”, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to the field of display technology, and in particular to a manufacturing method of a display substrate, a display substrate and a display device.

BACKGROUND

During manufacture of a liquid crystal display device, a Wire Grid Polarizer (WGP) is usually adopted to replace a polarizer disposed on a conventional display substrate, to realize ultra-thinness of the liquid crystal display device.

The process of forming a display substrate in a liquid crystal display device includes: first, forming a planarization layer on a base substrate on which a patterned film layer is formed; forming a buffer layer on the side, away from the base substrate, of the planarization layer; and forming a WGP on the side, away from the base substrate, of the buffer layer.

SUMMARY

The present disclosure provide a manufacturing method of a display substrate, a display substrate and a display device. The technical solutions are as follows.

In an aspect, there is provided a manufacturing method of a display substrate, comprising:

forming a first planarization layer on a base substrate on which patterned film layer is formed;

forming a first buffer layer on a side, away from the base substrate, of the first planarization layer;

forming a second buffer layer on a side, away from the base substrate, of the first buffer layer; and

forming a Wire Grid Polarizer (WGP) on a side, away from the base substrate, of the second buffer layer.

Optionally, the first buffer layer and the second buffer layer are made from different materials.

Optionally, the material for forming the first buffer layer comprises silicon nitride, and the material for forming the second buffer layer comprises silicon dioxide.

Optionally, prior to forming the first buffer layer on the side, away from the base substrate, of the first planarization layer, the method further comprises:

forming a second planarization layer on the side, away from the base substrate, of the first planarization layer, wherein the second planarization layer and the first planarization layer are made from different materials.

Optionally, after forming the second planarization layer on the side, away from the base substrate, of the first planarization layer, the method further comprises:

performing ashing on a side, away from the base substrate, of the second planarization layer.

Optionally, forming the second planarization layer on the side, away from the base substrate, of the first planarization layer comprises:

coating the side, away from the base substrate, of the first planarization layer with a planarization material; and

curing the planarization material to form the second planarization layer.

Optionally, the material for forming the first planarization layer comprises a resin material, and the planarization material for forming the second planarization layer comprises a fluorine-containing resin material.

Optionally, forming the WGP on the side, away from the base substrate, of the second buffer layer comprises:

forming a conductive thin film on the side, away from the base substrate, of the second buffer layer;

forming a hard mask on a side, away from the base substrate, of the conductive thin film;

coating a side, away from the base substrate, of the hard mask with an imprint resist;

imprinting the imprint resist with a nano imprint template to form an imprint pattern; and

etching the hard mask and the conductive thin film based on the imprint pattern, and stripping the residual hard mask to form the WGP.

Optionally, after forming the WGP on the side, away from the base substrate, of the second buffer layer, the method further comprises:

forming a protective layer on a side, away from the base substrate, of the WGP.

Optionally, the patterned film layer is a color film layer.

Optionally, the patterned film layer is a color film layer, the first planarization layer is made from a resin material, the first buffer layer is made from silicon nitride, and the second buffer layer is made from silicon dioxide;

before forming the first buffer layer on the side, away from the base substrate, of the first planarization layer, the method further comprises:

coating the side, away from the base substrate, of the first planarization layer with a planarization material which is a fluorine-containing resin material;

photocuring the planarization material to form the second planarization layer;

performing ashing on the side, away from the base substrate, of the second planarization layer; and

after forming the WGP on the side, away from the base substrate, of the second buffer layer, the method further comprises: forming a protective layer on the side, away from the base substrate, of the WGP.

In another aspect, there is provided a display substrate, comprising:

a patterned film layer on a base substrate and a first planarization layer on a side, away from the base substrate, of the patterned film layer;

a first buffer layer on a side, away from the base substrate, of the first planarization layer;

a second buffer layer on a side, away from the base substrate, of the first buffer layer; and

a WGP on a side, away from the base substrate, of the second buffer layer.

Optionally, the first buffer layer and the second buffer layer are made from different materials.

Optionally, the material for forming the first buffer layer comprises silicon nitride, and the material for forming the second buffer layer comprises silicon dioxide.

Optionally, the display substrate further comprises:

a second planarization layer between the first planarization layer and the first buffer layer, wherein the second planarization layer and the first planarization layer are made from different materials.

Optionally, the material for forming the first planarization layer comprises a resin material, and the planarization material for forming the second planarization layer comprises a fluorine-containing resin material.

Optionally, the display substrate further comprises:

a protective layer on a side, away from the base substrate, of the WGP.

Optionally, the patterned film layer is a color film layer.

Optionally, the patterned film layer is a color film layer, the material for forming the first buffer layer comprises silicon nitride, and the material for forming the second buffer layer comprises silicon dioxide; and

the display substrate further comprises: a protective layer on a side, away from the base substrate, of the WGP.

In yet another aspect, there is provided a display device, comprising the display substrate described in the above aspect.

DETAILED DESCRIPTION

Embodiments of the present disclosure will be described in further detail with reference to the accompanying drawings, to present the objects, technical solutions, and advantages of the present disclosure more clearly.

In the related art, during formation of a WGP, the material of a buffer layer chemically reacts with the material of a planarization layer, which damages the surface of the planarization layer and affects the planarization of the planarization layer.

An embodiment of the present disclosure provides a manufacturing method of a display substrate. As shown inFIG. 1, the method may include the following steps.

In step101, a first planarization layer is formed on a base substrate on which a patterned film layer is formed.

In the embodiment of the present disclosure, a patterned film layer may be formed on the base substrate first. Then, the first planarization layer130may be formed on the base substrate120on which the patterned film layer110is formed. Referring toFIG. 2for a schematic diagram of the base substrate120on which the first planarization layer130is formed. Exemplarily, the thickness of the first planarization layer130may be 2 μm and the first planarization layer130may be made from a resin material.

When the display substrate is a color film substrate, the patterned film layer110may be a color film layer. When the display substrate is an array substrate, the patterned film layer110may be a film layer including a TFT (Thin Film Transistor) therein. For example, the patterned film layer110may include a gate layer, a gate insulating layer, an active layer, a source/drain layer, etc. A gate of the TFT is formed in the gate layer. A source and a drain of the TFT are formed in the source/drain layer.

In step102, a first buffer layer is formed on the side, away from the base substrate, of the first planarization layer.

The first buffer layer140may be formed on the side, away from the base substrate120, of the first planarization layer130. Referring toFIG. 3for a schematic diagram of the base substrate120on which the first buffer layer140is formed.

In step103, a second buffer layer is formed on the side, away from the base substrate, of the first buffer layer.

The second buffer layer150may be formed on the side, away from the base substrate120, of the first buffer layer140. Referring toFIG. 4for a schematic diagram of the base substrate120on which the second buffer layer150is formed. Here, the material for forming the second buffer layer150may be the same as or different from the material for forming the first buffer layer140.

For example, both of the two buffer layers may be made from a silicon dioxide material. Alternatively, the first buffer layer140may be made from a silicon nitride material and the second buffer layer150may be made from a silicon dioxide material.

In step104, a WGP is formed on the side, away from the base substrate, of the second buffer layer.

In the embodiment of the present disclosure, the WGP160is formed on the side, away from the base substrate120, of the second buffer layer150by a nano imprinting process. Referring toFIG. 5for a schematic diagram of the base substrate120on which the WGP160is formed.

In summary, according to the manufacturing method of the display substrate, provided in the embodiment of the present disclosure, a first planarization layer may be formed on the base substrate on which a patterned film layer is formed. A first buffer layer is formed on the side, away from the base substrate, of the first planarization layer. Then, a second buffer layer is formed on the side, away from the base substrate, of the first buffer layer. At last, a WGP is formed on the side, away from the base substrate, of the second buffer layer. By forming two buffer layers on the base substrate, the thickness of the buffer layer increases. Thus, during formation of the WGP, the surface of the first planarization layer will not be damaged. In comparison with the related art, the planarization of the planarization layer is improved.

An embodiment of the present disclosure provides another manufacturing method of a display substrate. As shown inFIG. 6, the method may include the following steps.

In step201, a first planarization layer is formed on a base substrate on which a patterned film layer is formed.

In the embodiment of the present disclosure, when the display substrate is a color film substrate, the patterned film layer110may be a color film layer. When the display substrate is an array substrate, the patterned film layer110may be a film layer including a TFT therein.

Exemplarily, by taking the color film substrate as an example, as shown inFIG. 7, the color film layer110which includes a red color film1101, a green color film1102and a blue color film1103may be formed on the base substrate by a photoetching process. Here, the photoetching process may include photoresist coating, exposure, developing, etching and stripping of the photoresist. The color film layer110may have a thickness of 2.1 μm.

Optionally, during formation of the first planarization layer, the side, away from the base substrate120, of the patterned film layer110may be coated with a resin material. Then, thermocuring is performed on the resin material to form the first planarization layer130. Referring toFIG. 7for a schematic diagram of the base substrate120on which the first planarization layer130is formed. The first planarization layer may have a thickness of 2 μm.

In step202, a second planarization layer is formed on the side, away from the base substrate, of the first planarization layer.

Referring toFIG. 8for a schematic diagram of the base substrate120on which the second planarization layer170is formed. The second planarization layer170and the first planarization layer130may be made from different materials. For example, the material for forming the first planarization layer130may include a resin material, and the planarization material for forming the second planarization layer170may include a fluorine-containing resin material, to ensure that the second planarization layer and the first planarization layer have relatively strong adhesion. Thus, the planarization effect of the planarization layers (namely, the first planarization layer130and the second planarization layer170) is improved, which ensures that a WGP can be normally formed later. However, in the related art, after a planarization layer is formed on a base substrate on which a patterned film layer is formed, as planarization effect of the planarization layer is relatively poor, a WGP is difficult to be formed later.

Optionally, during formation of the second planarization layer170, the side, away from the base substrate120, of the first planarization layer130may be coated with a planarization material first. The planarization material may be a fluorine-containing resin material. After that, photocuring may be performed on the planarization material to form the second planarization layer170.

Exemplarily, photocuring may be performed on the planarization material by ultraviolet light to form the second planarization layer170. In the embodiment of the present disclosure, by performing photocuring on the planarization material, the strength of the second planarization layer may be improved, which facilitates follow-up formation of the WGP by a nano imprinting process.

In step203, asking is performed on the side, away from the base substrate, of the second planarization layer.

Optionally, the side, away from the base substrate120, of the second planarization layer170may be bombarded with oxygen plasma gas to change the structure on the surface of the second planarization layer170.

In step204, a first buffer layer is formed on the side, away from the base substrate, of the second planarization layer.

In the embodiment of the present disclosure, a first buffer layer140may be formed on the side, away from the base substrate120, of the second planarization layer170. Referring toFIG. 9for a schematic diagram of the base substrate120on which the first buffer layer140is formed.

Exemplarily, silicon nitride may be deposited on the side, away from the base substrate120, of the second planarization layer170to form the first buffer layer140. Here, silicon nitride may have a thickness of 1,000 Å (angstrom).

In the related art, a buffer layer is generally made from silicon dioxide, and the planarization layer is generally made from a resin material which contains carbon atoms. During follow-up formation of a WGP, since oxygen ions in the material of the buffer layer chemically reacts with the carbon atoms in the material of the planarization layer, the surface of the planarization layer is damaged, which affects the planarization of the planarization layer. In addition, since the adhesion between the buffer layer and the planarization layer is weak, during removal of a nano imprinting template, the buffer layer and the planarization layer may separate from each other easily.

In the embodiment of the present disclosure, since the first buffer layer140is made from silicon nitride, during follow-up formation of the WGP160, the material of the first buffer layer140does not chemically react with the material of the second planarization layer170. Thus, the surface of the second planarization layer170will not be damaged. In comparison with the related art, the planarization of the planarization layers is improved.

Moreover, by performing asking on the second planarization layer170, a contact angle between the second planarization layer170and the first buffer layer140is reduced. The contact angle refers to an angle between a liquid and the second planarization layer170after the liquid is dropped on the surface of the second planarization layer170. Thus, the adhesion between the second planarization layer170and the first buffer layer140is enhanced, and the first buffer140and the second planarization layer170are prevented from separation during follow-up removal of the nano imprinting template.

In step205, a second buffer layer is formed on the side, away from the base substrate, of the first buffer layer.

The second buffer layer150may be formed on the side, away from the base substrate120, of the first buffer layer140. Referring toFIG. 10for a schematic diagram of the base substrate120on which the second buffer layer150is formed.

Silicon dioxide may be deposited on the side, away from the base substrate120, of the first buffer layer140to form the second buffer layer150. Here, silicon dioxide may have a thickness of 800 Å.

Since the refraction index of the material of the upper film and lower film of the WGP160has a great impact on the transmittance of the WGP160, when the refraction index of the material of the upper film and lower film is 1.5, relatively excellent transmittance of the WGP160can be guaranteed. In the embodiment of the present disclosure, silicon dioxide is deposited on the side, away from the base substrate120, of the first buffer layer140, to serve as the second buffer layer150, which can guarantee that the WGP160has a relatively excellent transmittance and polarizing characteristic.

In step206, a conductive thin film is formed on the side, away from the base substrate, of the second buffer layer.

The conductive thin film001may be formed on the side, away from the base substrate120, of the second buffer layer150. The conductive thin film001may be made of aluminum. Referring toFIG. 11for a schematic diagram of the base substrate120on which the conductive thin film001is formed.

In step207, a hard mask is formed on the side, away from the base substrate, of the conductive thin film.

The hard mask002may be formed on the side, away from the base substrate120, of the conductive thin film001. Referring toFIG. 12for a schematic diagram of the base substrate120on which the hard mask002is formed.

Exemplarily, a layer of silicon dioxide is deposited on the side, away from the base substrate120, of the conductive thin film001, to serve as the hard mask002.

In step208, the side, away from the base substrate, of the hard mask is coated with an imprint resist.

Optionally, the side, away from the base substrate120, of the hard mask002may be coated with the imprint resist003by means of spin-coating. The imprint resist003may be a high polymer. Referring toFIG. 13for a schematic diagram of the base substrate120coated with the imprint resist003.

In step209, the imprint resist is imprinted by a nano imprintin template to form an imprint pattern.

The imprint resist003may be imprinted for multiple times by a nano imprinting template, to form the imprint pattern0031. Referring toFIG. 14for a schematic diagram of the base substrate120on which the imprint pattern0031is formed.

In step210, the hard mask and the conductive thin film are etched based on the imprint pattern and the residual hard mask is stripped to form the WGP.

In the embodiment of the present disclosure, the hard mask002may be etched first based on the imprint pattern0031, and the residual imprint resist003is stripped. That is, the imprint pattern0031is stripped to obtain a hard mask pattern0021shown inFIG. 15. Then, the conductive thin film001may be etched based on the hard mask pattern0021, and the residual hard mask002is stripped. That is, the hard mask pattern0021is stripped to form the WGP160. Referring toFIG. 16for a schematic diagram of the base substrate120on which the WGP160is formed.

In step211, a protective layer is formed on the side, away from the base substrate, of the WGP.

In the embodiment of the present disclosure, silicon dioxide may be deposited on the side, away from the base substrate120, of the WGP160, and silicon nitride may be deposited on the side, away from the base substrate120, of the deposited silicon dioxide to form the protective layer180. Referring toFIG. 17for a schematic diagram of the base substrate120on which the protective layer180is formed.

In summary, according to the manufacturing method of the display substrate provided in the embodiment of the present disclosure, a first planarization layer is formed on the base substrate on which a patterned film layer is formed. A second planarization layer is formed on the side, away from the base substrate, of the first planarization layer, and ashing is performed on the second planarization layer. A first buffer layer is formed on the side, away from the base substrate, of the second planarization layer. A second buffer layer is formed on the side, away from the base substrate, of the first buffer layer. A WGP is formed on the side, away from the base substrate, of the second buffer layer. By adding the second planarization layer and the first buffer layer, the planarization of the planarization layers is improved. In addition, by performing ashing on the second planarization layer, the adhesion between the second planarization layer and the first buffer layer increases, and the first buffer layer and the second planarization layer are prevented from separation during follow-up removal of the nano imprinting template.

An embodiment of the present disclosure provides a display substrate which may be manufactured by the manufacturing methods provided in the above embodiments. As shown inFIG. 1, the display substrate may include: a patterned film layer110on a base substrate120, a first planarization layer130on the side, away from the base substrate120, of the planarization front film layer110, a first buffer layer140on the side, away from the base substrate120, of the first planarization layer130, a second buffer layer150on the side, away from the base substrate120, of the first buffer layer140, and a WGP160on the side, away from the base substrate120, of the second buffer layer150.

The material for forming the first planarization layer130may include a resin material. The material for forming the first buffer layer140may include silicon nitride. The material for forming the second buffer layer150may include silicon dioxide.

In summary, a display substrate is provided in the embodiment of the present disclosure. The display substrate includes a patterned film layer on the base substrate, a first planarization layer on the side, away from the base substrate, of the patterned film layer, a first buffer layer on the side, away from the base substrate, of the first planarization layer, a second buffer layer on the side, away from the base substrate, of the first buffer layer and a WGP on the side, away from the base substrate, of the second buffer layer. By disposing two buffer layers on the base substrate, the thickness of the buffer layer increases. Thus, during formation of the WGP, the surface of the planarization layer will not be damaged. In comparison with the related art, the planarization of the planarization layer is improved.

Optionally, as shown inFIG. 17, the display substrate may further include: a second planarization layer170between the first planarization layer130and the first buffer layer140and a protective layer180on the side, away from the base substrate120, of the WGP160.

The patterned film layer110may be a color film layer. That is, the display substrate may be a color film substrate. The material for forming the first planarization layer130may include a resin material. The material for forming the second planarization layer170may include a fluorine-containing resin material. The first buffer layer140may be made from silicon nitride. The second buffer layer150may be made from silicon dioxide. The material for forming the protective layer180may include silicon dioxide and silicon nitride.

In summary, a display substrate is provided in the embodiment of the present disclosure. The display substrate includes a patterned film layer on the base substrate, a first planarization layer on the side, away from the base substrate, of the patterned film layer, a first buffer layer on the side, away from the base substrate, of the first planarization layer, a second buffer layer on the side, away from the base substrate, of the first buffer layer and a WGP located on the side, away from the base substrate, of the second buffer layer. By disposing two buffer layers on the base substrate, the thickness of the buffer layer increases. Thus, during formation of the WGP, the surface of the planarization layer will not be damaged. In comparison with the related art, the planarization of the planarization layer is improved.

An embodiment of the present disclosure provides a display device. The display device may include the display substrate provided in the above embodiments. For example, the display device may include the display substrate shown inFIG. 1orFIG. 17. The display device may be any product or component with a display function, such as a liquid crystal panel, a piece of electronic paper, a mobile phone, a tablet PC, a television, a display, a laptop computer, a digital photo frame or a navigator.

The foregoing descriptions are merely exemplary embodiments of the present disclosure, and are not intended to limit the present disclosure. Within the spirit and principles of the disclosure, any modifications, equivalent substitutions, improvements, etc., are within the protection scope of the present disclosure.