CN113061840A

CN113061840A - Evaporation mask plate, manufacturing method thereof and display panel

Info

Publication number: CN113061840A
Application number: CN202110275316.1A
Authority: CN
Inventors: 解洋; 徐景华; 孟维欣; 郭钟旭; 郭建
Original assignee: BOE Technology Group Co Ltd; Chongqing BOE Display Technology Co Ltd
Current assignee: BOE Technology Group Co Ltd; Chongqing BOE Display Technology Co Ltd
Priority date: 2021-03-15
Filing date: 2021-03-15
Publication date: 2021-07-02
Anticipated expiration: 2041-03-15
Also published as: CN113061840B

Abstract

The invention provides an evaporation mask plate, a manufacturing method thereof and a display panel, and belongs to the technical field of display. The vapor plating mask plate is arranged between the vapor plating source and the substrate to be vapor plated; at least one spacer is arranged on one side of the substrate to be evaporated, which is close to the evaporation source; the coating by vaporization mask plate includes: a mask plate body; the mask plate comprises a mask plate body and at least one groove arranged on the mask plate body, wherein elastic buffer materials are filled in the groove and are used for being in contact with a spacer and supporting the mask plate body. The technical scheme of the invention can solve the problem that the spacer in the substrate to be evaporated is scratched by the evaporation mask.

Description

Evaporation mask plate, manufacturing method thereof and display panel

Technical Field

The invention relates to the technical field of display, in particular to an evaporation mask plate, a manufacturing method thereof and a display panel.

Background

An Organic Light-Emitting Diode (OLED) display device has been classified as a next-generation display technology with great development prospect because of its advantages of thinness, lightness, wide viewing angle, active Light emission, continuously adjustable Light emission color, low cost, fast response speed, low energy consumption, low driving voltage, wide working temperature range, simple production process, high Light-Emitting efficiency, flexible display, etc.

Disclosure of Invention

The invention aims to provide an evaporation mask plate, a manufacturing method thereof and a display panel, and can solve the problem that a spacer in a substrate to be evaporated is scratched by the evaporation mask plate.

To solve the above technical problem, embodiments of the present invention provide the following technical solutions:

on one hand, the evaporation mask plate is arranged between an evaporation source and a substrate to be evaporated; at least one spacer is arranged on one side of the substrate to be evaporated, which is close to the evaporation source; the coating by vaporization mask plate includes:

a mask plate body;

the mask plate comprises a mask plate body and at least one groove arranged on the mask plate body, wherein elastic buffer materials are filled in the groove and are used for being in contact with a spacer and supporting the mask plate body.

In some embodiments, the grooves correspond to the spacers one to one; or the grooves correspond to the spacers in the edge area of the substrate to be evaporated one by one.

In some embodiments, a side surface of the elastic buffer material away from the groove bottom of the groove is flush with the mask body.

In some embodiments, the elastic buffer material is made of photoresist.

In some embodiments, a cross section of the groove in a direction perpendicular to the mask body is rectangular or semi-elliptical.

In some embodiments, when the elastic buffer material is in contact with the spacer, an orthographic projection of the spacer on the mask body is located in the corresponding groove.

In some embodiments, the depth of the groove is greater than 2 um.

The embodiment of the invention also provides a manufacturing method of the evaporation mask plate, wherein the evaporation mask plate is arranged between the evaporation source and the substrate to be evaporated; at least one spacer is arranged on one side of the substrate to be evaporated, which is close to the evaporation source; the manufacturing method of the evaporation mask plate comprises the following steps:

forming a mask plate body;

at least one groove is formed in the mask plate body, elastic buffer materials are filled in the groove, and the elastic buffer materials are used for being in contact with the spacer and supporting the mask plate body.

In some embodiments, the forming at least one groove on the mask body includes:

and coating photoresist on the mask plate body, exposing the photoresist, developing to form a photoresist retention area and a photoresist removal area, and etching the mask plate body in the photoresist removal area to form the groove.

In some embodiments, filling the groove with a resilient buffer material comprises:

elastic buffer material coats on the mask plate body, it is right elastic buffer material exposes, forms elastic buffer material retention area and elastic buffer material after the development and gets rid of the region, elastic buffer material retention area is in orthographic projection on the mask plate body with the recess coincidence adopts laser or mechanical grinding mode to get rid of elastic buffer material and surpasss the part of recess makes elastic buffer material keeps away from a side surface of the tank bottom of recess with the mask plate body flushes.

The embodiment of the invention also provides a display panel, which comprises a Thin Film Transistor (TFT) backboard and a pixel defining layer arranged on the TFT backboard; wherein the pixel defining layer includes a plurality of opening portions; the display panel also comprises an organic functional layer arranged in the opening part and a spacer arranged on the surface of the TFT backboard; at least one part of the organic functional layer is subjected to evaporation by adopting the evaporation mask plate.

The embodiment of the invention has the following beneficial effects:

according to the scheme, at least one groove is formed in a mask plate body of the evaporation mask plate, elastic buffer materials are filled in the groove, when the evaporation mask plate provided by the embodiment of the invention is used for evaporation, the evaporation mask plate is arranged between an evaporation source and a substrate to be evaporated, at least one spacer is arranged on one side, close to the evaporation source, of the substrate to be evaporated, and the spacer is in contact with the elastic buffer materials; in addition, it is possible to avoid vapor deposition drift and color mixing failure. Furthermore, the evaporation mask is generally made of metal and has a relatively large weight, and the evaporation mask is grooved and filled with an elastic buffer material, so that the weight of the evaporation mask can be reduced, and further, the evaporation PPA is reduced, wherein the evaporation PPA represents the position deviation between the actual evaporation position and the anode pattern of the TFT backboard.

Drawings

FIG. 1 is a schematic diagram of vapor deposition using a conventional vapor deposition mask;

fig. 2-5 are schematic cross-sectional views of an evaporation mask according to an embodiment of the invention;

FIG. 6 is a schematic diagram of vapor deposition using a vapor deposition mask according to an embodiment of the invention;

FIG. 7 is a schematic plan view of an evaporation mask according to an embodiment of the present invention;

fig. 8 to 13 are schematic views illustrating the fabrication of an evaporation mask according to an embodiment of the present invention.

Reference numerals

1 substrate base plate

2 thin film transistor array

3 spacer

4 vapor plating mask plate

41 groove

42 elastic buffer material

43 opening

44 mask plate body

Detailed Description

In order to make the technical problems, technical solutions and advantages to be solved by the embodiments of the present invention clearer, the following detailed description will be given with reference to the accompanying drawings and specific embodiments.

In the vapor deposition, as shown in fig. 1, a vapor deposition mask 4 is attached to a display substrate (including a substrate 1 and a thin film transistor array layer 2), and a spacer 3 is provided on the display substrate to support the vapor deposition mask. However, due to the non-uniformity of the spacer 3 and the wrinkles of the evaporation mask plate 4, the evaporation mask plate 4 is not in sufficient contact with the spacer 3 in the evaporation process, and the spacer 3 is easily scratched to generate foreign matters when being pressed or rubbed by the evaporation mask plate 4, so that the packaging layer can be punctured, and poor packaging can be caused; in addition, vapor deposition shifts and color mixing defects occur.

The embodiment of the invention provides an evaporation mask plate, a manufacturing method thereof and a display panel, and can solve the problem that a spacer in a substrate to be evaporated is scratched by the evaporation mask plate.

The embodiment of the invention provides an evaporation mask plate which is arranged between an evaporation source and a substrate to be evaporated; at least one spacer is arranged on one side of the substrate to be evaporated, which is close to the evaporation source; the coating by vaporization mask plate includes:

a mask plate body;

In the embodiment, at least one groove is formed in a mask plate body of the evaporation mask plate, and the groove is filled with an elastic buffer material, when the evaporation mask plate provided by the embodiment of the invention is used for evaporation, the evaporation mask plate is arranged between an evaporation source and a substrate to be evaporated, at least one spacer is arranged on one side, close to the evaporation source, of the substrate to be evaporated, and the spacer is in contact with the elastic buffer material; in addition, it is possible to avoid vapor deposition drift and color mixing failure. Furthermore, the evaporation mask is generally made of metal and has a relatively large weight, and the evaporation mask is grooved and filled with an elastic buffer material, so that the weight of the evaporation mask can be reduced, and further, the evaporation PPA is reduced, wherein the evaporation PPA represents the position deviation between the actual evaporation position and the anode pattern of the TFT backboard.

The grooves formed in the evaporation mask plate can correspond to the spacers arranged on the substrate to be evaporated one by one, in order to ensure the evaporation effect, when the elastic buffer material is contacted with the spacers, the orthographic projections of the spacers on the mask plate body are positioned in the corresponding grooves, so that the full contact between all the spacers and the evaporation mask plate can be ensured, the contact area between all the spacers and the evaporation mask plate is increased, the friction force is increased, the evaporation mask plate is not easy to slide during evaporation, foreign matters caused by scratches of the spacers are avoided, and the packaging effect is ensured; in addition, it is possible to avoid vapor deposition drift and color mixing failure. Moreover, the weight of the evaporation mask plate can be reduced to the greatest extent, and then the PPA is reduced.

Because the sliding of treating the evaporation substrate of evaporation mask plate generally takes place in marginal area, consequently, can only set up the recess at the marginal area of evaporation mask plate, the recess with treat the spacer one-to-one in evaporation substrate marginal area, in order to guarantee the coating by vaporization effect, when elastic buffer material and spacer contact, the orthographic projection of spacer on the mask plate body is located the recess that corresponds.

In order to ensure the sufficient contact between the spacer and the elastic buffer material, the maximum deformation of the elastic buffer material after being pressed by the spacer should not be less than the maximum height difference between the spacers, so that the spacer can be ensured to be in contact with the elastic buffer material in the corresponding groove during evaporation, and in order to ensure the maximum deformation of the elastic buffer material, the depth of the groove should be large enough to be filled with enough elastic buffer material, otherwise, the deformation of the elastic buffer material is small or the elastic buffer material is ineffective, and particularly, the depth of the groove can be larger than 2 um. Certainly, the degree of depth of recess should not too deeply, otherwise can make elastic buffer material's deformation too big, lead to the coating by vaporization mask plate and treat the coating by vaporization base plate and contact to also can have the mobility problem when coating elastic buffer material on the mask plate body, still can influence the structural strength of coating by vaporization mask plate, consequently, the degree of depth of recess should not be greater than 3 um.

In some embodiments, the elastic buffer material can be made of photoresist, the material has high photosensitivity, good elasticity after molding, high temperature resistance, water and oxygen resistance, good stability, difficulty in falling from the groove, and high mass production performance. Of course, the elastic buffer material is not limited to the above materials, and other materials having elasticity may be used.

In this embodiment, as shown in fig. 2 to 5, the evaporation mask includes an opening 43 for performing evaporation of the organic light emitting functional layer; the openings 43 correspond to pixel regions of a substrate to be vapor-deposited, and since spacers of the substrate to be vapor-deposited are disposed between the pixel regions, as shown in fig. 7, the grooves 41 disposed corresponding to the spacers and the elastic buffer material 42 filled therein are located between the openings 43, and thus the disposition of the openings 43 is not affected. The area of the groove needs to be larger than the area of the end of the spacer, but the arrangement of the groove does not affect the arrangement of the opening 43.

As shown in fig. 2, in some embodiments, a cross section of the groove in a direction perpendicular to the mask body is rectangular; the cross section of the groove in the direction vertical to the mask plate body can also be semi-elliptical. In some embodiments, as shown in fig. 4, the cross section of the groove in the direction perpendicular to the mask body may also be a combination of a rectangular shape and a semi-elliptical shape. The shape of the elastic buffer material 42 is matched with that of the groove 41, and in order to ensure the flatness of the evaporation mask plate, the surface of one side, away from the groove bottom of the groove 41, of the elastic buffer material 42 is flush with the mask plate body.

As shown in fig. 6, when the evaporation mask provided by the embodiment of the present invention is used for evaporation, the evaporation mask is disposed between an evaporation source and a substrate to be evaporated, a spacer 3 on the substrate to be evaporated contacts an elastic buffer material 42, and the elastic buffer material is compressed under the pressure of the spacer, so that the spacer can be sufficiently contacted with the evaporation mask, and the evaporation mask is not easy to slide.

forming a mask plate body;

In some embodiments, the forming at least one groove on the mask body includes:

In a specific example, as shown in fig. 8, a mask body 44 is provided, wherein the mask body 44 includes an opening 43 for evaporating an organic light-emitting functional layer; the mask body 44 is coated with a photoresist 5.

As shown in fig. 9, the photoresist 5 is exposed by using a mask plate, and a photoresist retention region and a photoresist removal region are formed after development, wherein the photoresist 5 can be exposed by using the mask plate for manufacturing the spacer, so that an additional mask plate is not required to be manufactured.

As shown in fig. 10, the mask body in the photoresist removal region is etched to form a groove.

The remaining photoresist is stripped as shown in fig. 11.

In a specific example, as shown in fig. 12, an elastic buffer material 6 is coated on the mask body 44 shown in fig. 11, and the elastic buffer material 6 is made of a photosensitive material.

As shown in fig. 13, the elastic buffer material 6 is exposed by using a mask plate, and an elastic buffer material retaining region and an elastic buffer material removing region are formed after development, wherein the elastic buffer material 6 can be exposed by using the mask plate for manufacturing the spacer, so that an additional mask plate does not need to be manufactured.

And then, removing the part of the elastic buffer material exceeding the groove by adopting a mechanical grinding mode, so that the surface of one side of the elastic buffer material, which is far away from the groove bottom of the groove, is flush with the mask plate body, and thus the evaporation mask plate of the embodiment is obtained. Or, the part of the elastic buffer material exceeding the groove can be removed in a laser mode, so that the side surface of the elastic buffer material, which is far away from the groove bottom of the groove, is flush with the mask plate body, and the evaporation mask plate of the embodiment is obtained.

When the part of the elastic buffer material exceeding the groove is removed by adopting a laser mode, carbon dioxide laser can be adopted, the laser energy is 0-10 uj, and the laser frequency is 0-100 KHZ; or a femtosecond laser is adopted, the laser energy is 0-20 uj, and the laser frequency is 0-200 KHZ; or a dye laser is adopted, the laser energy is 0-30 uj, and the laser frequency is 0-300 KHZ.

The display panel of the present embodiment is applied to a display device, which includes but is not limited to: radio frequency unit, network module, audio output unit, input unit, sensor, display unit, user input unit, interface unit, memory, processor, and power supply. It will be appreciated by those skilled in the art that the above described configuration of the display device does not constitute a limitation of the display device, and that the display device may comprise more or less of the components described above, or some components may be combined, or a different arrangement of components. In the embodiment of the present invention, the display device includes, but is not limited to, a display, a mobile phone, a tablet computer, a television, a wearable electronic device, a navigation display device, and the like.

The Display device provided by the embodiment of the invention is an electroluminescent Display device, and the electroluminescent Display device can be an Organic Light-Emitting Diode Display (OLED for short) or a Quantum Dot electroluminescent Display device (Quantum Dot Light Emitting Diodes (QLED for short)). Taking the organic electroluminescent display device as an example, the organic electroluminescent display device may be a PMOLED (Passive organic electroluminescent diode) or an AMOLED (Active organic electroluminescent diode).

The display panel includes a display substrate and an encapsulation layer for encapsulating the display substrate. Here, the encapsulation layer may be an encapsulation film; or may be a package substrate. When the sealing layer is a sealing film, the number of layers of the sealing film included in the sealing layer is not limited, and the sealing layer may include one layer of the sealing film, or may include two or more layers of the sealing films stacked. In some embodiments, the encapsulation layer comprises three layers of encapsulation films disposed one on top of the other.

In a case that the encapsulation layer includes three encapsulation films sequentially stacked, optionally, the encapsulation film located in the middle layer is made of an organic material, and the encapsulation films located at both sides are made of an inorganic material.

Here, the organic material is not limited, and the organic material may be, for example, pmma. The inorganic material is not limited, and may be one or more of SiNx (silicon nitride), SiOx (silicon oxide), or SiOxNy (silicon oxynitride), for example.

On the basis, the encapsulation film located in the intermediate layer can be manufactured by using an Ink Jet Printer (IJP for short). Further, the encapsulation films on both sides can be formed by Chemical Vapor Deposition (CVD).

The display substrate comprises a TFT backboard and light-emitting devices which are arranged on the TFT backboard and are arranged in an array.

The light emitting device includes an anode, an organic functional layer, and a cathode. The display substrate further comprises a pixel defining layer arranged on the TFT backboard, wherein the pixel defining layer comprises a plurality of opening parts; a light emitting device is disposed in one of the opening portions. The display substrate further includes spacers.

The substrate for display provided in the embodiment of the invention can be of a top-emission type, in which case the anode is in a non-light-transmitting state and the cathode is in a light-transmitting state. The display substrate may be a bottom emission type substrate, in which case the anode is in a light transmissive state and the cathode is in a light opaque state. The display substrate may be of a double-sided light emitting type, and in this case, the anode and the cathode are both in a light transmitting state.

In some embodiments, the organic functional layer comprises a light emitting layer. In other embodiments, the organic functional layer may further include one or more of an Electron Transport Layer (ETL), an Electron Injection Layer (EIL), a Hole Transport Layer (HTL), and a Hole Injection Layer (HIL) in addition to the light emitting layer.

Here, the electron injection layer, the electron transport layer, the hole injection layer, and the hole transport layer may be located only in the opening portion of the pixel defining layer; the electron injection layer, the electron transport layer, the hole injection layer, and the hole transport layer may be located not only in the opening of the pixel defining layer but also covering the surface of the pixel defining layer away from the TFT backplane, i.e., the electron injection layer, the electron transport layer, the hole injection layer, and the hole transport layer may be an entire layer.

It should be understood that one light emitting device corresponds to one sub-pixel. Illustratively, the sub-pixels include a red sub-pixel, a green sub-pixel, and a blue sub-pixel. On the basis, the light-emitting layer comprises a red light-emitting pattern positioned in a red sub-pixel, a green light-emitting pattern positioned in a green sub-pixel and a blue light-emitting pattern positioned in a blue sub-pixel.

In some embodiments, the electroluminescent display panel is produced by mainly forming an organic functional layer by an evaporation coating (vapor deposition) method. In the evaporation process, an evaporation mask is needed to deposit red, green, blue and other film layers to ensure that the organic material is evaporated at a specified position.

During the coating by vaporization, coating by vaporization mask plate and demonstration are laminated with the base plate, and at this moment, the spacer that base plate for demonstration includes plays the effect of supporting coating by vaporization mask plate. The mask plate body comprises a plurality of openings and a shielding part located on the periphery of the openings.

The shape of the opening is not limited. The shape of the opening is the same as that of the opening portion of the pixel defining layer, that is, the opening of the sub-pixel. Illustratively, the shape of the opening portion of the pixel defining layer is a hexagon, and in this case, the shape of the opening is also a hexagon; of course, the shape of the opening of the pixel defining layer may be rectangular, and the shape of the opening may also be rectangular.

In addition, when the electron injection layer, the electron transport layer, the hole injection layer, and the hole transport layer in the organic functional layer are only located in the opening of the pixel defining layer, the electron injection layer, the electron transport layer, the hole injection layer, and the hole transport layer may be evaporated by using the evaporation mask provided in the embodiment of the present invention. That is to say, the evaporation mask provided by the embodiment of the invention can be used for evaporating the light-emitting layer, and also can be used for evaporating the electron injection layer, the electron transport layer, the hole injection layer and the hole transport layer.

It should be noted that, in the present specification, all the embodiments are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the embodiments, since they are substantially similar to the product embodiments, the description is simple, and the relevant points can be referred to the partial description of the product embodiments.

Unless otherwise defined, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure belongs. The use of "first," "second," and similar terms in this disclosure is not intended to indicate any order, quantity, or importance, but rather is used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.

It will be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" or "under" another element, it can be "directly on" or "under" the other element or intervening elements may be present.

In the foregoing description of embodiments, the particular features, structures, materials, or characteristics may be combined in any suitable manner in any one or more embodiments or examples.

The above description is only for the specific embodiments of the present disclosure, but the scope of the present disclosure is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present disclosure, and all the changes or substitutions should be covered within the scope of the present disclosure. Therefore, the protection scope of the present disclosure shall be subject to the protection scope of the claims.

Claims

1. An evaporation mask plate is characterized by being arranged between an evaporation source and a substrate to be evaporated; at least one spacer is arranged on one side of the substrate to be evaporated, which is close to the evaporation source; the coating by vaporization mask plate includes:

a mask plate body;

2. An evaporation mask according to claim 1, wherein the grooves correspond to the spacers one to one; or the grooves correspond to the spacers in the edge area of the substrate to be evaporated one by one.

3. An evaporation mask according to claim 1, wherein the surface of one side of the elastic buffer material away from the groove bottom of the groove is flush with the mask body.

4. An evaporation mask according to claim 1, wherein the elastic buffer material is photoresist.

5. An evaporation mask according to claim 1, wherein the cross section of the groove in the direction perpendicular to the mask body is rectangular or semi-elliptical.

6. An evaporation mask according to claim 2 or 3, wherein when the elastic buffer material is in contact with the spacer, the orthographic projection of the spacer on the mask body is located in the corresponding groove.

7. An evaporation mask according to claim 1, wherein the depth of the grooves is greater than 2 um.

8. The manufacturing method of the evaporation mask plate is characterized in that the evaporation mask plate is arranged between an evaporation source and a substrate to be evaporated; at least one spacer is arranged on one side of the substrate to be evaporated, which is close to the evaporation source; the manufacturing method of the evaporation mask plate comprises the following steps:

forming a mask plate body;

9. The method of claim 8, wherein the forming at least one groove on the mask body comprises:

10. The method of claim 8, wherein filling the recess with an elastic buffer material comprises:

11. A display panel is characterized by comprising a Thin Film Transistor (TFT) backboard and a pixel defining layer arranged on the TFT backboard; wherein the pixel defining layer includes a plurality of opening portions; the display panel also comprises an organic functional layer arranged in the opening part and a spacer arranged on the surface of the TFT backboard; at least one part of the organic functional layer is evaporated by adopting the evaporation mask plate as claimed in any one of claims 1 to 7.