Mask assembly and method for manufacturing the same and display device

Patent metadata

Field	Value
Publication number	US-10648070-B2
Application number	US-201715745401-A
Country	US
Kind code	B2
Filing date	May 17, 2017
Priority date	Jun 15, 2016
Publication date	May 12, 2020
Grant date	May 12, 2020

Abstract

The present disclosure provides a mask assembly and a method for manufacturing the same, and a display device. The mask assembly includes a frame, a first mask and a second mask, and the first mask and the second mask are superposed on the frame; the first mask includes an opening region, the second mask includes an evaporation region in which a first evaporation hole is provided for allowing an evaporation material to pass therethrough and a buffer region surrounding the evaporation region and configured to block off the evaporation material, and an orthographic projection of the boundary of the opening region onto the second mask is located within the buffer region.

First claim

What is claimed is:

1. A mask assembly, comprising a frame, a first mask and a second mask, the first mask and the second mask being superposed on the frame;
wherein the first mask comprises an opening region, the second mask comprises an evaporation region in which a first evaporation hole is provided for allowing an evaporation material to pass therethrough and a buffer region surrounding the evaporation region and configured to block off the evaporation material, and an orthographic projection of a boundary of the opening region onto the second mask is located within the buffer region,
wherein a plurality of first recesses are provided in the buffer region and spaced from each other, and
wherein an area of an opening face of the first evaporation hole is equal to an area of an opening face of each of the first recesses.

2. The mask assembly according to claim 1 , wherein,
the plurality of first recesses function as a first buffer structure and are configured to reduce a stress difference between the buffer region and the evaporation region.

3. The mask assembly according to claim 1 , wherein,
opening faces of the first recesses are located at a face of the second mask facing away from the first mask.

4. The mask assembly according to claim 1 , wherein the buffer region has an annular shape.

5. The mask assembly according to claim 1 , wherein,
the first mask further comprises a first peripheral region surrounding the opening region and configured to block off the evaporation material; and
the second mask further comprises a second peripheral region surrounding the buffer region, and an orthographic projection of the second peripheral region onto the first mask is located within the first peripheral region.

6. The mask assembly according to claim 5 , wherein,
a second buffer structure is provided in the second peripheral region and configured to reduce a stress difference between the second peripheral region and the evaporation region, and the second buffer structure comprises a second evaporation hole and/or a second recess formed in the second peripheral region.

7. The mask assembly according to claim 1 , wherein,
the mask assembly comprises at least one of following items (1) to (9):
(1) a plurality of evaporation holes are provided in the evaporation region, and opening faces of all the evaporation holes have areas equal to each other;
(2) opening faces of all the first recesses have areas equal to each other;
(3) a plurality of evaporation holes are provided in the evaporation region, and an area of an opening face of each of the evaporation holes is equal to an area of an opening face of each of the first recesses;
(4) a depth of each of the first recesses is larger than or equal to a half of a thickness of the second mask and smaller than the thickness of the second mask;
(5) the opening region has a circular shape;
(6) the evaporation region has a circular shape;
(7) the buffer region has an annular shape;
(8) a radius of an inner ring of the buffer region is equal to a radius of the evaporation region; and
(9) a radius of the opening region is larger than the radius of the inner ring of the buffer region and smaller than a radius of an outer ring of the buffer region.

8. The mask assembly according to claim 1 , wherein,
the frame is a metal frame, the second mask is a fine metal mask, and the first mask and the second mask are welded onto the frame respectively.

9. A method for manufacturing a mask assembly, comprising steps of:
providing a frame;
forming a first mask comprising an opening region;
forming a second mask, the second mask comprising an evaporation region in which a first evaporation hole is provided for allowing an evaporation material to pass therethrough and a buffer region surrounding the evaporation region and configured to block off the evaporation material; and
superposing the first mask and the second mask on the frame, such that an orthographic projection of a boundary of the opening region onto the second mask is located within the buffer region,
wherein a plurality of first recesses are provided in the buffer region and spaced from each other, and
wherein an area of an opening face of the first evaporation hole is equal to an area of an opening face of each of the first recesses.

10. The method according to claim 9 , wherein the step of forming a second mask comprises forming, in the buffer region, the plurality of first recesses as a first buffer structure, the plurality of first recesses being configured to reduce a stress difference between the buffer region and the evaporation region.

11. The method according to claim 9 , wherein,
opening faces of the first recesses are located at a face of the second mask facing away from the first mask.

12. The method according to claim 9 , wherein the buffer region has an annular shape.

13. The method according to claim 9 , wherein,
the first mask further comprises a first peripheral region surrounding the opening region and configured to block off the evaporation material;
the second mask further comprises a second peripheral region surrounding the buffer region, and
the step of superposing the first mask and the second mask on the frame further comprises:
superposing the first mask and the second mask on the frame such that an orthographic projection of the second peripheral region onto the first mask is located within the first peripheral region.

14. The method according to claim 13 , wherein, a second buffer structure is provided in the second peripheral region and configured to reduce a stress difference between the second peripheral region and the evaporation region, and the second buffer structure comprises a second evaporation hole and/or a second recess formed in the second peripheral region.

15. The method according to claim 13 , wherein,
the mask assembly is manufactured such that it comprises at least one of following items (1) to (9):
(1) a plurality of evaporation holes are provided in the evaporation region, and opening faces of all the evaporation holes have areas equal to each other;
(2) opening faces of all the first recesses have areas equal to each other;
(3) a plurality of evaporation holes are provided in the evaporation region, and an area of an opening face of each of the evaporation holes is equal to an area of an opening face of each of the first recesses;
(4) a depth of each of the first recesses is larger than or equal to a half of a thickness of the second mask and smaller than the thickness of the second mask;
(5) the opening region has a circular shape;
(6) the evaporation region has a circular shape;
(7) the buffer region has an annular shape;
(8) a radius of an inner ring of the buffer region is equal to a radius of the evaporation region; and
(9) a radius of the opening region is larger than the radius of the inner ring of the buffer region and smaller than a radius of an outer ring of the buffer region.

16. The method according to claim 9 , wherein,
the frame is a metal frame, and the second mask is a fine metal mask, and
the step of superposing the first mask and the second mask on the frame comprises:
welding the first mask and the second mask onto the frame respectively such that the first mask and the second mask are superposed on each other.

17. A display device, comprising a pattern formed by using the mask assembly of claim 1 .

18. The mask assembly according to claim 6 , wherein,
the mask assembly comprises at least one of following items (1) to (9):
(1) a plurality o

Assignees

• Boe Technology Group Co Ltd
• Ordos Yuansheng Optoelectronics Co Ltd

Inventors

• Li Dongwei
• Li Baojun
• Huang Chun Chieh

Classifications

• C23C14/24 Primary

  Vacuum evaporation · CPC title

• C23C14/042 Primary

  using masks · CPC title

• C23C14/04 Primary

  Coating on selected surface areas, e.g. using masks · CPC title

• H01L27/3223

  Electricity · mapped topic

• H10K59/00

  Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00 · CPC title