CN110724905B

CN110724905B - Mask sheet, mask sheet and preparation method of mask sheet

Info

Publication number: CN110724905B
Application number: CN201911012834.3A
Authority: CN
Inventors: 曾佳; 陈奎; 贺雪英; 曹东旭; 张雷
Original assignee: BOE Technology Group Co Ltd; Chengdu BOE Optoelectronics Technology Co Ltd
Current assignee: BOE Technology Group Co Ltd; Chengdu BOE Optoelectronics Technology Co Ltd
Priority date: 2019-10-23
Filing date: 2019-10-23
Publication date: 2023-09-12
Anticipated expiration: 2039-10-23
Also published as: CN110724905A

Abstract

The invention provides a mask, a mask and a preparation method thereof, relates to the technical field of display, and can improve the evaporation effect of the mask. The mask plate comprises a frame and a plurality of mask plates which are spanned on the frame. The mask piece comprises a main body part, a first splicing part and a second splicing part, wherein the first splicing part and the second splicing part are positioned at two sides of the main body part along the width direction of the mask piece; the main body portion is provided with a plurality of first pixel holes. The sum of the thicknesses of the first splicing part and the second splicing part is equal to the thickness of the main body part; the lower surface of the first splicing part is flush with the lower surface of the main body part, and the upper surface of the second splicing part is flush with the upper surface of the main body part; in any adjacent mask sheet, the first splice of one mask sheet overlaps the second splice of the other mask sheet. The region between the main body parts of any adjacent mask sheets is provided with a plurality of second pixel holes, and all the first pixel holes and all the second pixel holes are integrally and uniformly arranged in an array.

Description

Mask sheet, mask sheet and preparation method of mask sheet

Technical Field

The invention relates to the technical field of display, in particular to a mask sheet, a mask plate and a preparation method of the mask sheet.

Background

An Organic Light-Emitting Diode (OLED) is also called an Organic laser display, and has advantages of self-luminescence, wide viewing angle, high contrast ratio, low power consumption, and high reaction speed.

Various film layers are often included in OLED display devices, including, for example, anodes, cathodes, light-emitting layers, and the like. Therefore, when preparing an OLED display device, each film layer in the OLED display device needs to be evaporated onto a glass substrate to be evaporated by an evaporation process, and for the evaporation of some film layers, an FMM (Fine Metal MASK) is required to be used, so that an evaporation material is evaporated to a designed position through a through hole on the FMM to form a designed film layer pattern.

Disclosure of Invention

The embodiment of the invention provides a mask, a mask and a preparation method thereof, which can improve the evaporation effect of the mask and reduce the maintenance cost of the mask.

In order to achieve the above purpose, the embodiment of the present invention adopts the following technical scheme:

in one aspect, a mask is provided, including a main body portion, a first splicing portion and a second splicing portion, where the first splicing portion and the second splicing portion are located at two sides of the main body portion along a width direction of the mask; the main body portion is provided with a plurality of first pixel holes.

The sum of the thicknesses of the first splicing part and the second splicing part is equal to the thickness of the main body part; the lower surface of the first splicing part is flush with the lower surface of the main body part, and the upper surface of the second splicing part is flush with the upper surface of the main body part.

Optionally, the thickness of the first splice is equal to the thickness of the second splice.

On the other hand, a mask plate is provided, which comprises a frame and a plurality of mask plates spanned on the frame.

The mask piece comprises a main body part, a first splicing part and a second splicing part, wherein the first splicing part and the second splicing part are positioned at two sides of the main body part along the width direction of the mask piece; the main body portion is provided with a plurality of first pixel holes.

The sum of the thicknesses of the first splicing part and the second splicing part is equal to the thickness of the main body part; the lower surface of the first splicing part is flush with the lower surface of the main body part, and the upper surface of the second splicing part is flush with the upper surface of the main body part; in any adjacent mask sheets, the first splicing part of one mask sheet overlaps with the second splicing part of the other mask sheet.

And a plurality of second pixel holes are formed in the area between the main body parts of any adjacent mask pieces, and all the first pixel holes and all the second pixel holes are integrally and uniformly arranged in an array.

Optionally, the width of the second splice is greater than the width of the first splice.

In the region between the main body parts of any adjacent mask, part of the second pixel holes only penetrate through the second splicing part, and part of the second pixel holes penetrate through the second splicing part and the first splicing part at the same time.

Optionally, in any two adjacent mask sheets, a space is provided between the second splicing portion of one mask sheet and the main body portion of the other mask sheet.

The distance between two adjacent first pixel holes is smaller than the distance between two adjacent first pixel holes along the width direction of the mask.

Optionally, the pitch ranges from 10 μm to 500 μm.

In still another aspect, a method for manufacturing a mask is provided, the mask includes: a plurality of masking sheets; the mask piece comprises a main body part, a first splicing part and a second splicing part, wherein the first splicing part and the second splicing part are positioned at two sides of the main body part along the width direction of the mask piece; the main body portion is provided with a plurality of first pixel holes.

The sum of the thicknesses of the first splicing part and the second splicing part is equal to the thickness of the main body part, the lower surface of the first splicing part is flush with the lower surface of the main body part, and the upper surface of the second splicing part is flush with the upper surface of the main body part.

The preparation method of the mask plate comprises the following steps:

and sequentially screen-welding a plurality of mask sheets on a frame, and overlapping the first splicing part of one mask sheet with the second splicing part of the other mask sheet in any two adjacent mask sheets.

And forming a plurality of second pixel holes in the area between the main body parts of any adjacent mask pieces, wherein all the first pixel holes and all the second pixel holes are integrally and uniformly arranged in an array.

Optionally, forming a plurality of second pixel holes in a region between the main body portions of any adjacent mask sheet includes:

and placing the frame on a laser processing machine, and enabling the mask to be clung to the laser processing machine through a magnetic force generating device positioned below the laser processing machine.

And punching holes in the area between the main body parts of any adjacent mask sheets by using a laser emitter to form a plurality of second pixel holes.

Placing the frame on a laser processing machine, comprising:

and turning the frame 180 degrees and placing the frame on a laser processing machine table so that the second splicing part is in contact with the laser processing machine table.

Optionally, forming the mask sheet includes:

dividing the mask body into three areas, namely a middle area and edge areas respectively positioned at two sides of the middle area.

Etching the edge area of the mask body through a half-etching technology to form the first splicing part and the second splicing part respectively; the mask body located in the middle area is the main body.

The embodiment of the invention provides a mask, a mask and a preparation method thereof, wherein the mask comprises a plurality of masks, and a first splicing part and a second splicing part are arranged on two sides of a main body part of the mask; in any adjacent mask sheets, the first splicing part of one mask sheet overlaps the second splicing part of the other mask sheet, and a plurality of second pixel holes are formed in the area between the main body parts of any adjacent mask sheets. On the one hand, a plurality of mask plates are arranged, only the damaged mask plates are needed to be replaced, and the mask plates are small in size, small in gravity and small in sagging amount along the thickness direction, so that the color mixing defect can be improved, and the evaporation effect is improved; meanwhile, as the width of the mask is smaller, wrinkles are not easy to occur when the expanded mesh is stretched, the color mixing defect can be further improved, and the evaporation effect is improved. On the other hand, in any adjacent mask, the first splicing part of one mask overlaps with the second splicing part of the other mask, when the lower surface of the first splicing part is flush with the lower surface of the main body part, the upper surface of the second splicing part is flush with the upper surface of the main body part, and the sum of the thicknesses of the first splicing part and the second splicing part is equal to the thickness of the main body part, when the mask is aligned and stretched and welded, only the width of the area between the main body parts of any adjacent mask is required to be controlled, and the requirements on the alignment precision, the stretching precision and the processing precision of the mask are lower. In still another aspect, a plurality of second pixel holes are formed in an area between the main body portions of any adjacent mask, and each second pixel hole can be machined once after the mask is welded to the frame, so that requirements on machining precision and alignment precision of the mask are low. Therefore, the mask plate provided by the embodiment of the invention can solve the problems of larger sagging amount, more folds, higher production and maintenance cost and poorer evaporation effect of the mask plate in the related technology.

Drawings

In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1a is a schematic structural diagram of an OLED display panel according to an embodiment of the present invention;

fig. 1b is a schematic structural diagram of a light emitting device according to an embodiment of the present invention;

fig. 1c is a schematic structural diagram of a light-emitting functional layer according to an embodiment of the present invention;

fig. 2a is a schematic top view of a mask according to an embodiment of the present invention;

FIG. 2b is a schematic cross-sectional view taken along line A-A' in FIG. 2 a;

fig. 3a is a schematic top view of another mask according to an embodiment of the present invention;

FIG. 3B is a schematic cross-sectional view in the direction B-B' of FIG. 3 a;

fig. 4a is a schematic top view of another mask according to an embodiment of the present invention;

FIG. 4b is a schematic cross-sectional view taken in the direction C-C' of FIG. 4 a;

fig. 5a is a schematic top view of another mask according to an embodiment of the present invention;

FIG. 5b is a schematic cross-sectional view in the direction D-D' of FIG. 5 a;

fig. 6a is a schematic top view of another mask according to an embodiment of the present invention;

FIG. 6b is a schematic cross-sectional view in the E-E' direction of FIG. 6 a;

FIG. 7 is a schematic top view of a mask plate according to the related art;

FIG. 8a is a schematic top view of another related art mask;

FIG. 8b is a schematic cross-sectional view in the direction G-G' of FIG. 8 a;

FIG. 8c is another schematic cross-sectional view in the direction G-G' of FIG. 8 a;

fig. 9a is a schematic flow chart of a method for preparing a mask according to an embodiment of the present invention;

fig. 9b is a schematic diagram of a preparation process of a mask according to an embodiment of the present invention;

FIG. 9c is a schematic cross-sectional view in the H-H' direction of FIG. 9 b;

fig. 9d is a schematic diagram of a preparation process of another mask according to an embodiment of the present invention;

FIGS. 10a to 10d are schematic views illustrating a preparation process of another mask plate according to an embodiment of the present invention;

FIG. 11a is a schematic diagram illustrating a preparation process of a mask sheet according to an embodiment of the present invention;

fig. 11b is a schematic structural diagram of a mask according to an embodiment of the present invention;

FIG. 11c is a schematic cross-sectional view in the direction I-I' of FIG. 11 b.

Reference numerals:

a 1-OLED display panel; 10-a substrate; 11-a light emitting device; 110-an anode; a 111-cathode; 112-a light emitting functional layer; 1120 a light emitting layer; 12-a filter unit; 13-a pixel driving circuit; 2-mask plate; 20-frame; 21-masking sheet; 210-a body portion; 2100—first pixel aperture; 211-a first splice; 212-a second splice; 213-the area between the body parts; 2130-second pixel holes; 214-pixel aperture; 214-stretching part; 22-first mask stripes; 23-second mask stripes; 24-pixel aperture; 3-a laser processing device; 31-a laser processing machine; 32-a magnetic force generating device; 33-a laser emitter; 4-mask body; 41-middle region; 42-edge area; 5-connecting part.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

With the development of display technology, flexible display technology represented by an OLED (Organic Light-Emitting Diode) display device has been attracting more and more attention. Compared with a liquid crystal display device, the OLED display device has the excellent characteristics of self-luminescence, no need of a backlight source, high contrast, thin thickness, wide visual angle, high response speed, flexibility, wide use temperature range, simpler structure and manufacturing process and the like, and is considered as an emerging application technology of the next-generation flat panel display.

In the OLED display device, the quality of the OLED display panel is the most important factor determining the quality of the OLED display device, and thus, attention is paid to the manufacturing process of the OLED display panel.

As shown in fig. 1a, the OLED display panel 1 includes a substrate 10, and a light emitting device 11 disposed on the substrate 10 and located in each subpixel.

The substrate 10 may be a flexible substrate, and the material thereof may be polyimide, for example.

As shown in fig. 1b, the light emitting device 11 includes an anode 110, a cathode 111, and a light emitting functional layer 112 between the anode 110 and the cathode 111. The light emitting device 11 may be classified into a bottom emission type, a top emission type, and a double-sided emission type. Taking the example that the anode 110 is close to the substrate 10 and the cathode 111 is located on the side of the anode 110 away from the substrate 10, when the light emitting device 11 is a bottom light emitting type, the material of the anode 110 may be a transparent conductive material such as ITO (Indium Tin Oxides, indium tin oxide); the material of the cathode 111 is a metal, which may be silver, for example; when the light emitting device 11 is a top emission type, the structure of the anode 110 is a multilayer laminated structure including a transparent conductive layer and an opaque metal layer, for example, a three-layer laminated structure of ITO/Ag/ITO, and the material of the cathode 111 is metal, in which case the thickness of the cathode 111 is thin and semi-transparent; when the light emitting device 11 is of a double-sided light emitting type, the material of the anode 110 is a transparent conductive material, the material of the cathode 111 is a metal, and the thickness of the cathode 111 is thin and semi-transparent.

The light emitting functional layer 112 includes at least a light emitting layer. The light emitting layer serves to generate light under the action of the anode 110 and the cathode 111.

As shown in fig. 1c, the light emitting functional layer 112 may include ETL (election transporting layer, electron transport layer) 1121, EIL (election injection layer, electron injection layer) 1122, HTL (hole transporting layer, hole transport layer) 1123, and HIL (hole injection layer ) 1124, in addition to the light emitting layer 1120. Note that the light emitting functional layer 112 is not limited to include only the combination of the light emitting layer 1120 and the ETL1121, EIL1122, HTL1123, HIL1124, but may include other functional layers.

The material of the light emitting layer 1120 may be, for example, an organic light emitting material, and the material of the light emitting layer 1120 determines the light emitting color of the light emitting device 11.

The light emitting device 11 may have one of three primary colors, for example, red, green, and blue. As illustrated in fig. 1a, the plurality of subpixels includes a red subpixel R, a green subpixel G, and a blue subpixel B. One light emitting device 11 is included in each of the red subpixel R, the green subpixel G, and the blue subpixel B. Wherein, in the red subpixel R, the light emitting device 11 is for emitting red light; in the green subpixel G, the light emitting device 11 is for emitting green light; in the blue subpixel B, the light emitting device 11 is for emitting blue light.

It will be appreciated that the light emitting devices 11 in each sub-pixel are formed simultaneously in fabrication.

At least when the light emitting layer 1120 in the light emitting device 11 is fabricated, a mask made of metal is used to deposit an organic light emitting material by vacuum evaporation technology to form the light emitting layer 1120.

Based on the above, as shown in fig. 2a to 6b, an embodiment of the present invention proposes a mask 2, which includes a frame 20 and a plurality of mask sheets 21 straddling the frame 20.

The mask sheet 21 includes a main body portion 210, a first splice portion 211, and a second splice portion 212, the first splice portion 211 and the second splice portion 212 being located on both sides of the main body portion 210 in the width direction of the mask sheet 21; the body portion 210 is provided with a plurality of first pixel holes 2100.

The sum of the thicknesses of the first and second splice parts 211 and 212 is equal to the thickness of the main body part 210; the lower surface of the first splicing part 211 is flush with the lower surface of the main body part 210, and the upper surface of the second splicing part 212 is flush with the upper surface of the main body part 210; in any adjacent mask sheets 21, the first stitch portion 211 of one mask sheet 21 overlaps the second stitch portion 212 of the other mask sheet 21.

The region 213 between the main body portions 210 of any adjacent mask sheets 21 is provided with a plurality of second pixel holes 2130, and all the first pixel holes 2100 and all the second pixel holes 2130 are arrayed and uniformly arranged as a whole.

As shown in fig. 2a to 6b, the main body 210 is provided with a plurality of first pixel holes 2100 which are uniformly arranged in an array, and the plurality of first pixel holes 2100 may be formed by etching, laser, or the like.

The sum of the thicknesses of the first and second spliced portions 211 and 212 disposed at both sides of the width direction of the main body portion 210 is equal to the thickness of the main body portion 210, including three cases in which the thickness of the first spliced portion 211 is greater than the thickness of the second spliced portion 212, the thickness of the first spliced portion 211 is equal to the thickness of the second spliced portion 212, and the thickness of the first spliced portion 211 is less than the thickness of the second spliced portion 212.

Optionally, the thickness of the first splice 211 is equal to the thickness of the second splice 212.

The following describes, by way of example, the first mask and the second mask respectively as any two adjacent masks 21, and the region 213 between the main body portions 210 and the second pixel hole 2130 of the two adjacent masks 21, respectively, including the following cases:

first kind: as shown in fig. 2a and 2b, the width of the first joint portion 211 is equal to the width of the second joint portion 212, and the orthographic projections of the first joint portion 211 of the second mask sheet and the second joint portion 212 of the first mask sheet completely coincide in the thickness direction of the mask sheet 21. In this case, the region 213 between the main portions 210 of the two adjacent mask sheets 21 is the region of the first mask sheet where the second splicing portion 212 of the second mask sheet is located. As can be seen, each of the second pixel holes 2130 penetrates the stacked first and second splice portions 211 and 212 in the region 213 between the body portions 210 of any adjacent mask sheets 21.

Second kind: as shown in fig. 3a and 3b, the width of the first spliced portion 211 is equal to the width of the second spliced portion 212, and the orthographic projection portions of the first spliced portion 211 of the second mask sheet and the second spliced portion 212 of the first mask sheet overlap in the thickness direction of the mask sheet 21. In this case, the region 213 between the main body portions 210 of the adjacent two mask pieces 21 includes: the orthographic projection overlapping area of the second stitching portion 212 of the first mask sheet and the first stitching portion 211 of the second mask sheet, the spacing H between the main body portion 210 of the first mask sheet and the first stitching portion 211 of the second mask sheet, and the spacing H between the main body portion 210 of the second mask sheet and the second stitching portion 212 of the first mask sheet. In order to ensure that the second pixel holes 2130 are formed in the region 213 between the body portions 210 of any two adjacent mask sheets 21, and that the second pixel holes 2130 and the first pixel holes 2100 are uniformly distributed, H may be smaller than the distance L between any two adjacent first pixel holes 2100.

Based on this, in the width direction of the mask sheet 21, according to the width of the orthographic projection overlapping region of the second joint 212 of the first mask sheet and the first joint 211 of the second mask sheet 21, and the size of h, the second pixel hole 2130 may be provided in the orthographic projection overlapping region of the second joint 212 of the first mask sheet and the first joint 211 of the second mask sheet 21, at which time the second pixel hole 2130 penetrates the stacked first joint 211 and second joint 212; and/or, the second pixel hole 2130 may be disposed between the main body portion 210 of the first mask and the first joint portion 211 of the second mask, where the second pixel hole 2130 only penetrates the second joint portion 212 of the first mask.

Third kind: as shown in fig. 4a and 4b, the width of the first spliced portion 211 is smaller than the width of the second spliced portion 212, and the orthographic projection portions of the first spliced portion 211 of the second mask sheet and the second spliced portion 212 of the first mask sheet overlap in the thickness direction of the mask sheet 21. In this case, the region 213 between the main body portions 210 of the adjacent two mask pieces 21 includes: the orthographic projection overlapping area of the second stitching portion 212 of the first mask sheet and the first stitching portion 211 of the second mask sheet, the spacing H between the main body portion 210 of the first mask sheet and the first stitching portion 211 of the second mask sheet, and the spacing H between the main body portion 210 of the second mask sheet and the second stitching portion 212 of the first mask sheet. In order to ensure that the second pixel holes 2130 are formed in the region 213 between the main portions 210 of any two adjacent mask sheets 21, and the second pixel holes 2130 and the first pixel holes 2100 are uniformly distributed in an array, H may be smaller than the distance L between any two adjacent first pixel holes 2100.

Fourth kind: as shown in fig. 5a and 5b, the width of the first spliced portion 211 is smaller than the width of the second spliced portion 212, and the orthographic projection portions of the first spliced portion 211 of the second mask sheet and the second spliced portion 212 of the first mask sheet overlap in the thickness direction of the mask sheet 21. In this case, the region 213 between the main body portions 210 of the adjacent two mask pieces 21 includes: the orthographic projection overlapping area of the second splicing part 212 of the first mask sheet and the first splicing part 211 of the second mask sheet, and the distance h between the main body part 210 of the first mask sheet and the first splicing part 211 of the second mask sheet.

Fifth: as shown in fig. 6a and 6b, the width of the first spliced portion 211 is larger than the width of the second spliced portion 212, and the orthographic projection portions of the first spliced portion 211 of the second mask sheet and the second spliced portion 212 of the first mask sheet overlap in the thickness direction of the mask sheet 21. In this case, the region 213 between the main body portions 210 of the adjacent two mask pieces 21 includes: the orthographic projection overlapping area of the second spliced portion 212 of the first mask sheet and the first spliced portion 211 of the second mask sheet, and the space H between the main body portion 210 of the second mask sheet and the second spliced portion 212 of the first mask sheet. In order to ensure that the second pixel holes 2130 are formed in the region 213 between the body portions 210 of any two adjacent mask sheets 21, and that the second pixel holes 2130 and the first pixel holes 2100 are uniformly distributed, H may be smaller than the distance L between any two adjacent first pixel holes 2100.

Based on this, in the width direction of the mask sheet 21, the second pixel hole 2130 is provided in the orthographic projection overlapping region of the second joint 212 of the first mask sheet and the first joint 211 of the second mask sheet 21 according to the width of the orthographic projection overlapping region of the second joint 212 of the first mask sheet and the first joint 211 of the second mask sheet 21, and the size of H, and at this time, the second pixel hole 2130 penetrates the stacked first joint 211 and second joint 212.

On the basis of the above, since all the first pixel holes 2100 and all the second pixel holes 2130 are arrayed and uniformly arranged as a whole, it is understood that the plurality of second pixel holes 2130 provided in the region 213 between the main body portions 210 of any adjacent mask sheets 21 are arrayed and uniformly arranged while the distance between any adjacent two second pixel holes 2130 is equal to the distance between any adjacent two first pixel holes 2100. That is, the distance between any adjacent two of the second pixel holes 2130 in the width direction of the mask sheet 21 is also equal to L.

The above-described pitch H is smaller than the distance L between any adjacent two of the first pixel holes 2100, that is, also smaller than the distance L between any adjacent two of the second pixel holes 2130, in which case it can be ensured that when the second pixel holes 2130 are formed in the region 213 between the main body portions 210 of any adjacent mask sheets 21, the second pixel holes 2130 can be uniformly distributed, and when the distance between the adjacent second pixel holes 2130 is equal to L, the distance between the second pixel holes 2130 and the adjacent first pixel holes 2100 is also equal to L, thereby ensuring that the second pixel holes 2130 and the first pixel holes 2100 are uniformly distributed in an array as a whole. The second pixel hole 2130 located in the region 213 between the main body portions 210 of any adjacent mask sheets 21 may penetrate only the second joint portion 212, or may penetrate both the first joint portion 211 and the second joint portion 212.

Alternatively, the top views of the first and second pixel holes 2100 and 2130 may be, for example, quadrangular, hexagonal, circular, and the like. By way of example, the top view of the first and second pixel holes 2100 and 2130 is a quadrangle, and its longitudinal section may be, for example, a trapezoid, i.e., the structure of the second pixel hole 2130 as shown in fig. 2b, 3b, 4b, 5b, and 6 b.

In the use of the mask 2, as shown in fig. 2a to 6b, the surface of the upper surface of the second splicing portion 212 and the surface of the upper surface of the main body portion 210 may be a surface of the mask 2 that is close to a side of the glass substrate to be vapor deposited during use.

As shown in fig. 2a to 6b, the main body 210 has 3 rows of first pixel holes 2100, and the region 213 between the main body 210 of two adjacent mask sheets 21 has 2 rows of second pixel holes 2130, which is only an example, but the embodiment of the present invention is not limited thereto. Here, since the width of the main body portion 210 is much larger than the width of the region 213 between the main body portions 210 of the adjacent two mask sheets 21, the number of the first pixel holes 2100 located in the main body portion 210 is actually much larger than the number of the second pixel holes 2130. The present invention presents structural features of the main body portion 210 and the region 213 between the main body portions 210 of two adjacent mask sheets 21 for clarity, thus reducing the variability in the widths of the two.

As shown in fig. 7, in one related art, the mask plate 2 includes a frame 20 and a first mask bar 22, and a plurality of pixel holes 24 are formed in the first mask bar 22. The first mask strip 22 is fixed to the frame 20 by stretching the first mask strip and then welding the first mask strip. When the expanded mesh is stretched, a tensile stress is generated in the first mask strip 22, and the tensile stress is used for counteracting a thermal stress generated when the first mask strip 22 is heated by evaporation, and the thermal stress is generated by expansion of the first mask strip 22 after being heated. The first mask bar 22 is welded to the frame 20 on both sides in the width direction, and is not stretched in the width direction, that is, in the X direction shown in fig. 7, but is stretched in the width direction, that is, in the length direction of the first mask bar 22, and is welded to the frame 20 on both sides in the length direction of the first mask bar 22, that is, in the Y direction shown in fig. 7. That is, during the stretching process of the expanded metal, the first mask strip 22 is not stressed in the width X direction, and is only stressed in the length Y direction. In vapor deposition, the width of the first mask strip 22 is increased due to the thermal stress and the gravity influence of the first mask strip 22, so that a larger sagging amount occurs along the thickness direction of the first mask strip 22, and the sagging amount can influence the tightness degree of the mask plate 2 and the glass substrate to be vapor deposited, thereby causing color mixing defects. In the length Y direction of the first mask strip 22, although the tensile stress generated during stretching of the expanded mesh can counteract the thermal stress, the length increase of the first mask strip 22 in the Y direction is reduced to avoid a larger sagging amount along the thickness direction of the first mask strip 22. However, since the first mask strip 22 has a larger size, the required tensile stress is also larger, and since the thickness of the first mask strip 22 is smaller, the first mask strip 22 is thinner, when the tensile stress generated during the stretching of the expanded mesh is greater than the buckling critical load of the first mask strip 22, a plurality of folds extending and distributed along the X direction will be generated in the first mask strip 22, and the probability of occurrence of color mixing will be further increased by the folds, thereby affecting the vapor deposition effect of the mask plate 2. Meanwhile, in the related art, a large-sized first mask bar 22 is used, and when the first mask bar 22 is partially damaged, the entire first mask bar 22 needs to be replaced, and the maintenance cost of the mask plate 2 is high.

As shown in fig. 8a, in another related art, a plurality of second mask strips 23 are straddled on the frame 20, and half of pixel holes 24 are respectively formed at edges of adjacent second mask strips 23, and after the two second mask strips 23 are spliced, two half of pixel holes 24 at edges of the two second mask strips can be spliced to form a complete pixel hole 24. In this related art, since one pixel hole 24 is divided into two parts, there is a high demand for processing accuracy at the edge of the second mask bar 23. As shown in fig. 8b, when the machining precision is high, the net stretching precision and the alignment precision are high, the pixel holes 24 having the shape conforming to the design requirements can be spliced, but even then, the cost expenditure increased when the machining precision is improved, the net stretching precision and the alignment precision are improved is not neglected. However, even if the processing precision can be achieved, the edges of the second mask strips 23 are easily deformed due to the influence of transportation and stretching of the expanded mesh, and the edges of the two deformed second mask strips 23 cannot be spliced to form the pixel holes 24 with shapes meeting the design requirements. As shown in fig. 8c, when the processing precision, the net-opening precision and the alignment precision are low, and the edges of the second mask strips 23 are deformed, the two second mask strips 23 cannot be spliced to form the pixel holes 24 with shapes conforming to the design requirements, and when the mask plate 2 is used for vapor deposition, the vapor deposition effect is poor.

With the development of OLED technology, the display panel prepared by the OLED can be applied to small-size mobile phones and large-size display devices such as notebook computers and vehicle-mounted displays. However, as the size of the display panel increases, the size of the mask plate which is inevitably used to manufacture the display panel increases, and as shown in fig. 7, there are mainly two problems if the first mask stripes 22 are used in an excessively large size as a whole: firstly, along the thickness direction of the mask plate 2, the sagging amount of the first mask strip 22 increases; secondly, when the width of the first mask strip 22 increases along the X direction, the risk of wrinkling of the first mask strip 22 during stretching increases. Or, as shown in fig. 8a, if the mask plate 2 is prepared by splicing the plurality of second mask strips 23, the requirements on the processing precision, the net-opening precision and the alignment precision are higher, the product yield is liable to be reduced, the production cost is increased, and the risk of color mixing is also liable to be increased when the above various precision are lower. Therefore, both of the above two related technologies increase the risk of color mixing during vapor deposition, and the vapor deposition effect is poor, thereby affecting the final quality of the display panel.

Therefore, in order to solve the above problems in the related art, in the mask plate 2 provided in the embodiment of the present invention, a plurality of mask plates 21 are included, and a first splicing portion 211 and a second splicing portion 212 are provided at both sides of a main body portion 210 of the mask plate 21; in any adjacent mask sheets 21, the first stitching 211 of one mask sheet 21 overlaps the second stitching 212 of the other mask sheet 21, and the region 213 between the main body portions 210 of any adjacent mask sheets 21 is provided with a plurality of second pixel holes 2130. On the one hand, a plurality of mask sheets 21 are arranged, only the damaged mask sheets 21 need to be replaced, and the plurality of mask sheets 21 are smaller in size and smaller in gravity and sag along the thickness direction, so that the color mixing defect can be improved, and the evaporation effect is improved; meanwhile, due to the small width of the mask sheet 21, wrinkles are not easy to occur during the stretching of the expanded mesh, and the color mixing defect can be further improved, so that the evaporation effect is improved. On the other hand, in any adjacent mask sheet 21, the first splicing portion 211 of one mask sheet 21 overlaps the second splicing portion 212 of the other mask sheet 21, so that when the lower surface of the first splicing portion 211 is flush with the lower surface of the main body portion 210, the upper surface of the second splicing portion 212 is flush with the upper surface of the main body portion 210, and the sum of the thicknesses of the first splicing portion 211 and the second splicing portion 212 is equal to the thickness of the main body portion 210, only the width of the region 213 between the main body portions 210 of any adjacent mask sheet 21 needs to be controlled during alignment and expanded metal stretch welding, and the requirements on alignment accuracy, expanded metal accuracy and machining accuracy of the mask sheet 21 are low. In still another aspect, the region 213 between the main portions 210 of any adjacent mask sheets 21 is provided with a plurality of second pixel holes 2130, and each second pixel hole 2130 may be finished at a time after the mask sheet 21 is welded to the frame 20, and the processing precision and alignment precision of the mask sheet 21 are also required to be low. Therefore, the mask plate 2 provided by the embodiment of the invention can solve the problems of larger sagging amount, more folds, higher production and maintenance cost and poorer evaporation effect of the mask plate 2 in the related art.

Alternatively, as shown in fig. 4b and 5b, the width of the second splice 212 is greater than the width of the first splice 211. In the region 213 between the main body portions 210 of any adjacent mask sheets 21, part of the second pixel holes 2130 penetrate only the second joint portions 212, and part of the second pixel holes 2130 penetrate both the stacked second joint portions 212 and first joint portions 211.

Since the upper surface of the second splicing portion 212 is closer to the glass substrate to be evaporated during evaporation, and since the hole wall of the second pixel hole 2130 has a certain gradient, the side of the second pixel hole 2130 closer to the glass substrate to be evaporated has a larger influence on evaporation. Therefore, in the present invention, the second pixel hole 2130 penetrates at least the second joint 212, and in order to facilitate the processing of the second pixel hole 2130, the width of the overlapping region between the first joint 211 and the second joint 212 is reduced, so that more second pixel holes 2130 penetrate only the second joint, so that the width of the second joint 212 is set to be greater than the width of the first joint 211.

Alternatively, as shown in fig. 3b, 4b, and 6b, in any two adjacent mask sheets 21, a space H is provided between the second spliced portion 212 of one mask sheet 21 and the main body portion 210 of the other mask sheet 21. The pitch H is smaller than the distance L between two adjacent first pixel holes 2100 in the width direction of the mask sheet 21.

In stretch-welding the mask sheet 21 to the frame, it is only necessary to control the spacing H between the second splice 212 and the main body 210 of the adjacent mask sheet 21. The method for controlling the alignment of the two adjacent mask sheets 21 is realized by controlling the single factor of the spacing H, so that the alignment difficulty is reduced, and the net-stretching precision of the mask sheets 21 is also reduced. The length of the first splicing part 211 positioned at the lower side of the second splicing part 212 does not affect the evaporation effect, so that the first splicing part 211 and the second splicing part 212 can be aligned more conveniently.

When the pitch H is smaller than the distance L between the two first pixel holes 2100, the pitch H does not affect the fabrication of the second pixel holes 2130 located at one side of the pitch H, so that the second pixel holes 2130 can be formed at one time during the fabrication.

Alternatively, the pitch H may range from 10 μm to 500 μm.

The pitch H is in the pixel hole level, and when set in the above range, the first pixel hole 2100 and the second pixel hole 2130 can be easily manufactured.

Optionally, the frame 20 and the mask 21 are made of metal, and the metal includes elemental metal and alloy, and the metal alloy may be invar, for example.

The embodiment of the invention also provides a method for preparing the mask plate 2, as shown in fig. 2a, 3a, 4a, 5a and 6a, the mask plate 2 comprises: a plurality of mask sheets 21; wherein, the mask sheet 21 includes a main body portion 210, a first splicing portion 211 and a second splicing portion 212, and the first splicing portion 211 and the second splicing portion 212 are located at two sides of the main body portion 210 along the width direction of the mask sheet 21; the body portion 210 is provided with a plurality of first pixel holes 2100.

The sum of the thicknesses of the first and second splice parts 211 and 212 is equal to the thickness of the main body part 210, and the lower surface of the first splice part 211 is flush with the lower surface of the main body part 210, and the upper surface of the second splice part 212 is flush with the upper surface of the main body part 210.

As shown in fig. 9a, the method for preparing the mask plate 2 includes:

s1, as shown in fig. 9b and 9c, a plurality of mask sheets 21 are sequentially welded on the frame 20 in a net-like manner, and the first joint portion 211 of one mask sheet 21 overlaps the second joint portion 212 of the other mask sheet 21 in any two adjacent mask sheets 21.

For example, as shown in fig. 9d, each mask sheet 21 is stretched and welded to the frame 20 in sequence. During the web stretching, the stretching jig is in contact with the stretching portion of each mask sheet 21. After all the mask sheets 21 are welded to the frame 20, the stretched portions 214 of all the mask sheets 21 are sheared, and the structure of the sheared semi-finished mask sheet is shown in fig. 9 b.

As illustrated in fig. 9b and 9c, the width of the first splicing portion 211 is equal to the width of the second splicing portion 212, and in the thickness direction of the mask sheet 21, the second splicing portion 212 of one mask sheet 21 completely coincides with the orthographic projection of the first splicing portion 211 of the other mask sheet 21 in the adjacent two mask sheets 21.

Note that, the relationship between the widths and the overlapping positions of the first and second splice parts 211 and 212 is not limited to the relationship shown in fig. 9c, and other cases refer to the relationship between the widths and the overlapping positions of the first and second splice parts 211 and 212 shown in fig. 2a to 6b, and only the relationship shown in fig. 9c is illustrated here.

S2, as shown in fig. 2b, a plurality of second pixel holes 2130 are formed in the region 213 between the main portions 210 of any adjacent mask sheets 21, and all the first pixel holes 2100 and all the second pixel holes 2130 are arrayed and uniformly arranged as a whole.

Illustratively, a plurality of second pixel holes 2130 are formed in the region 213 between the body portions 210 of any adjacent mask sheets 21 by means of laser etching.

Since the width of the region 213 between the main body portions 210 of any adjacent mask sheets 21 is small, the time required for laser processing is short, the processing efficiency is high, and the processing accuracy is high.

According to the preparation method of the mask sheets 21 provided by the embodiment of the invention, the first splicing part 211 and the second splicing part 212 are arranged on the two sides of the main body part 210 of each mask sheet 21, so that when the mask sheets 21 are welded on the frame 20 in a net-like manner, the first splicing part 211 and the second splicing part 211 of the adjacent mask sheets 21 are overlapped; then, a second pixel hole 2130 is formed in the region 213 between the main portions 210 of any two adjacent mask sheets 21 by means of laser etching. On the one hand, the second pixel holes 2130 are processed by laser etching, and each second pixel hole 2130 is formed at one time, so that the processing efficiency is high. On the other hand, the processing is performed in the region 213 between the main body portions 210 of any two adjacent mask sheets 21, and the alignment accuracy requirements for the two adjacent mask sheets 21 are low, so that the alignment efficiency of the plurality of mask sheets 21 can be improved. On the other hand, by adopting a mode of splicing a plurality of mask plates 21, the sagging amount of the mask plates 21 in the width direction during vapor plating can be reduced, and the mask plates 21 are not easy to generate wrinkles during the stretching of a net, so that the probability of occurrence of color mixing defects is reduced, the vapor plating effect is ensured, and meanwhile, the maintenance cost of the mask plates 2 can be reduced. Therefore, the preparation method of the mask plate 2 provided by the embodiment of the invention can prepare the mask plate with small sagging amount, difficult generation of wrinkles, good evaporation effect and low production and maintenance cost.

Optionally, a plurality of second pixel holes 2130 are formed in the area 213 between the body portions 210 of any adjacent mask sheets 21, including:

s10, as shown in fig. 10a, the frame 20 welded with the mask sheet 21 is placed on the laser processing machine 31, and the mask sheet 21 is brought into close contact with the laser processing machine 31 by the magnetic force generating device 32 located below the laser processing machine 31.

The frame 20 welded with the mask sheet 21 is placed on the laser processing machine 31 in the laser processing device 3, the surface of the second joint 212 is brought into contact with the laser processing machine 31, and the magnetic force generating device 32 located below the laser processing machine 31 can generate magnetic force, so that the mask sheet 21 made of metal can be adsorbed on the laser processing machine 31.

S11, as shown in fig. 10b, a plurality of second pixel holes 2130 are formed by punching holes in the region 213 between the main body portions 210 of any adjacent mask sheets 21 by the laser emitter 33.

The laser is utilized for punching, the operation is simple, and the processing efficiency and the processing precision are high.

Alternatively, as shown in fig. 10c, the width of the second splice 212 is greater than the width of the first splice 211.

Placing the frame 20 on the laser processing machine 31 includes:

the frame 20 is turned 180 ° and placed on the laser processing machine 31 so that the second splice 212 is in contact with the laser processing machine 31.

The longitudinal section of the second pixel hole 2130 is, for example, trapezoidal. Because the hole walls of the second pixel holes 2130 have a certain gradient, and in each second pixel hole 2130, the size of the opening near one end of the second joint 212 is smaller than the size of the opening near one end of the first joint 211, the frame 20 is turned 180 ° to facilitate the processing of the inclination angle of the hole walls of the second pixel holes 2130. Meanwhile, the second pixel holes 2130 are processed after the frame 20 is turned over by 180 degrees, so that burrs on the edges of the second pixel holes 2130 on one side, close to the glass substrate to be evaporated, of the mask plate 2 during evaporation can be reduced, and the risks of scratching and scratching the glass substrate to be evaporated by the mask plate 2 are reduced.

Since the second pixel hole 2130 always penetrates the second joint 212 and may or may not penetrate the first joint 211, the width of the first joint 211 has little effect on processing the second pixel hole 2130, and thus the width of the second joint 212 is larger than that of the first joint 211, so that the overall width of the mask 21 can be reduced and the production cost of the mask 21 can be reduced without affecting the processing of the second pixel hole 2130.

It should be noted that, when the second pixel hole 2130 is processed, the half-sheet mask plate may not be turned over, but the positional relationship between the laser processing apparatus 3 and the half-sheet mask plate is shown in fig. 10d, that is, the laser emitter 33 may always process the second pixel hole 2130 from the side where the first joint 211 is located (the opposite side of the mask plate 2 near the glass substrate to be evaporated during evaporation), regardless of the position between the laser processing apparatus 3 and the half-sheet mask plate.

In the structure shown in fig. 10a to 10d, when the second joint portion 212 of the one mask sheet 21 located at the rightmost end is connected to the frame 20, since a gap is provided between the second joint portion 212 and the frame 20, the second joint portion 212 and the frame 20 need to be connected to each other by the connecting portion 5. For example, the connection portion 5 may be, for example, solder, or may be integrally formed with the second joint portion 212, or may be integrally formed with the frame 20, which is not limited thereto.

Optionally, forming the mask sheet 21 includes:

as shown in fig. 11a, the mask body 4 is divided into three regions, namely a middle region 41 and edge regions 42 located on both sides of the middle region 41.

As shown in fig. 11b, the edge area 42 of the mask body 4 is etched by a half-etching technology to form a first splicing part 211 and a second splicing part 212 respectively; the mask body 4 located in the intermediate region 41 is a main body 210. The main body portion 210 is provided with a plurality of first pixel holes 2100 arranged in an array.

For example, the half-engraving technique may be implemented using an ashing process or a half-tone mask plate 2.

The embodiment of the present invention further provides a mask sheet 21, as shown in fig. 11b, including a main body portion 210, a first splicing portion 211, and a second splicing portion 212, where the first splicing portion 211 and the second splicing portion 212 are located at two sides of the main body portion 210 along the width direction of the mask sheet 21; the body portion 210 is provided with a plurality of first pixel holes 2100.

As shown in fig. 11c, the sum of the thicknesses of the first and second spliced portions 211 and 212 is equal to the thickness of the main body portion 210; the lower surface of the first splice 211 is flush with the lower surface of the main body 210, and the upper surface of the second splice 212 is flush with the upper surface of the main body 210.

It will be appreciated that in the embodiment of the present invention, for each mask sheet 21, when the mask sheet 2 is not assembled, the thicknesses of the portions of the areas where the first and second spliced portions 211 and 212 are located are identical, and no hole exists.

The mask 21 can be used for manufacturing the mask 2, so that it has the same beneficial effects as the mask 2, and therefore will not be described again.

Optionally, the thickness of the first splice 211 is equal to the thickness of the second splice 212. The first and second joints 211 and 212 are conveniently formed by half-engraving techniques, respectively.

The foregoing is merely illustrative of the present invention, and the present invention is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. The mask plate is characterized by comprising a frame and a plurality of mask plates which are spanned on the frame;

the mask piece comprises a main body part, a first splicing part and a second splicing part, wherein the first splicing part and the second splicing part are positioned at two sides of the main body part along the width direction of the mask piece; one mask sheet only comprises one first splicing part and one second splicing part; the first splicing part is strip-shaped, and the length of the first splicing part is equal to the length of the mask sheet; the second splicing part is strip-shaped, and the length of the second splicing part is equal to the length of the mask sheet; the main body part is provided with a plurality of first pixel holes;

the sum of the thicknesses of the first splicing part and the second splicing part is equal to the thickness of the main body part; the lower surface of the first splicing part is flush with the lower surface of the main body part, and the upper surface of the second splicing part is flush with the upper surface of the main body part; in any adjacent mask sheets, the first splicing part of one mask sheet overlaps with the second splicing part of the other mask sheet; the width of the second splicing part is larger than that of the first splicing part;

A plurality of second pixel holes are formed in the area between the main body parts of any adjacent mask sheets, part of the second pixel holes only penetrate through the second splicing parts, and part of the second pixel holes penetrate through the second splicing parts and the first splicing parts at the same time; all the first pixel holes and all the second pixel holes are integrally and uniformly arranged in an array.

2. The mask plate according to claim 1, wherein in any two adjacent mask plates, a space is provided between the second splicing part of one mask plate and the main body part of the other mask plate;

3. The mask plate according to claim 2, wherein the pitch ranges from 10 μm to 500 μm.

4. A preparation method of a mask plate is characterized in that the mask plate comprises the following steps: a plurality of masking sheets; the mask piece comprises a main body part, a first splicing part and a second splicing part, wherein the first splicing part and the second splicing part are positioned at two sides of the main body part along the width direction of the mask piece; one mask sheet only comprises one first splicing part and one second splicing part; the first splicing part is strip-shaped, and the length of the first splicing part is equal to the length of the mask sheet; the second splicing part is strip-shaped, and the length of the second splicing part is equal to the length of the mask sheet; the main body part is provided with a plurality of first pixel holes;

The sum of the thicknesses of the first splicing part and the second splicing part is equal to the thickness of the main body part, the lower surface of the first splicing part is flush with the lower surface of the main body part, and the upper surface of the second splicing part is flush with the upper surface of the main body part;

the preparation method of the mask plate comprises the following steps:

sequentially screen-welding a plurality of mask sheets on a frame, and overlapping the first splicing part of one mask sheet with the second splicing part of the other mask sheet in any two adjacent mask sheets; the width of the second splicing part is larger than that of the first splicing part;

forming a plurality of second pixel holes in the area between the main body parts of any adjacent mask sheets, wherein part of the second pixel holes only penetrate through the second splicing parts, and part of the second pixel holes penetrate through the second splicing parts and the first splicing parts at the same time; all the first pixel holes and all the second pixel holes are integrally and uniformly arranged in an array.

5. The method of manufacturing a mask plate according to claim 4, wherein forming a plurality of second pixel holes in a region between the body portions of any adjacent mask plates, comprises:

Placing the frame on a laser processing machine, and enabling the mask to be closely attached to the laser processing machine through a magnetic force generating device positioned below the laser processing machine;

6. The method of claim 5, wherein placing the frame on a laser processing tool comprises:

7. The method for preparing a mask plate according to claim 4, wherein forming the mask plate comprises:

dividing the mask body into three areas, namely a middle area and edge areas respectively positioned at two sides of the middle area;