TWI805984B - Metal mask - Google Patents

Abstract

A metal mask includes at least one working section and a peripheral blank section. The working section includes a peripheral part and a central part. The peripheral part has a plurality of first openings, whereas the central part has a plurality of second openings, in which the peripheral part surrounds and is connected to the central part, and the thickness of the peripheral part is thicker than that of the central part. The peripheral blank section surrounds and is connected to the working sections.

Description

metal mask

The present invention relates to a mask, and in particular to a metal mask suitable for making a patterned film layer.

At present, some organic light-emitting diode display panels (Organic Light-Emitting Diode Display Panel, OLED Display Panel) are manufactured by evaporation process, wherein the evaporation process usually uses a metal mask to make a plurality of organic light-emitting diode display panels. The light-emitting diode element, and the metal mask can be formed by lithography and wet etching of the metal plate. The metal mask has openings that are typically formed by wet etching.

Affected by the loading effect of wet etching, the etching rate is not the same everywhere on the metal plate, so that the size of these openings is not uniform. For example, in the same metal mask, the openings at the edges have a significantly larger size, but the openings at the center have a significantly smaller size. These openings with inconsistent sizes are not conducive to the manufacture of high-resolution OLED display panels, so that it is difficult to further improve the resolution of most OLED display panels.

At least one embodiment of the present invention provides a metal mask suitable for making a patterned film layer.

The metal mask provided by at least one embodiment of the present invention includes at least one working area and peripheral blank areas. The working block includes a peripheral part and a central part. The peripheral portion has a plurality of first openings, and the central portion has a plurality of second openings, wherein the peripheral portion surrounds and connects the central portion, and the peripheral portion has a thickness greater than that of the central portion. The peripheral blank block surrounds and connects with the working block.

In at least one embodiment of the present invention, the metal mask has a first surface and a second surface opposite to the first surface, and the first openings and the second openings both extend to the first surface and the second surface. Each first opening has a first annular rib and a first side wall. The first annular rib is located between the first surface and the second surface. The first side wall is connected between the first surface and the first annular ribs, wherein the first annular ribs are substantially located on the reference plane. A first included angle is formed between the first side wall and the reference plane, wherein the first included angle is less than 90 degrees. Each second opening has a second annular rib and a second side wall. The second annular rib is located between the first surface and the second surface, and the second side wall is connected between the first surface and the second annular rib, wherein the second annular ribs are substantially located on the reference plane. A second included angle is formed between the second side wall and the reference plane, wherein the second included angle is smaller than the first included angle.

In at least one embodiment of the present invention, the changes of the first included angles in the above-mentioned peripheral portion decrease gradually from the peripheral blank area toward the central portion.

In at least one embodiment of the present invention, the metal mask has a first surface and a second surface opposite to the first surface, and the first openings and the second openings both extend to the first surface and the second surface. The first surface has a plurality of dot-like planes, and these dot-like planes are distributed in the surrounding portion, and are not distributed in the peripheral blank area.

In at least one embodiment of the present invention, the above-mentioned first surface further has a plurality of endpoints, and these endpoints are only distributed in the central portion, and not distributed in the peripheral portion and the peripheral blank area.

In at least one embodiment of the present invention, at least one end point is located between four adjacent second openings.

In at least one embodiment of the present invention, at least one point-shaped plane is located between four adjacent first openings.

In at least one embodiment of the present invention, the first openings and the second openings are arranged in an array.

Based on the above, using the first openings and the second openings, the metal mask of at least one embodiment of the present invention is suitable for making patterned film layers, and is especially suitable for making multiple light emitting layers of OLED display panels.

In the following text, in order to clearly present the technical features of this application, the dimensions (such as length, width, thickness, and depth) of elements (such as layers, films, substrates, and regions) in the drawings will be enlarged in a non-proportional manner. Therefore, the description and explanation of the following embodiments are not limited to the size and shape of the elements in the drawings, but should cover the deviations in size, shape and both caused by actual manufacturing process and/or tolerances. For example, a planar surface shown in the drawings may have rough and/or non-linear features, while acute angles shown in the drawings may be rounded. Therefore, the components shown in the drawings of this case are mainly for illustration, and are not intended to accurately depict the actual shape of the components, nor are they used to limit the scope of the patent application of this case.

Secondly, words such as "about", "approximately" or "substantially" appearing in the content of this case not only cover the clearly stated values and numerical ranges, but also cover The allowable deviation range, wherein the deviation range can be determined by the error generated during measurement, and this error is caused by the limitation of the measurement system or process conditions, for example. Additionally, "about" can mean within one or more standard deviations of the above numerical values, eg, within ±30%, ±20%, ±10%, or ±5%. Words such as "about", "approximately" or "substantially" appearing in this text can choose the acceptable deviation range or standard deviation according to optical properties, etching properties, mechanical properties or other properties, not a single The standard deviation is used to apply all properties such as the above optical properties, etching properties, mechanical properties and other properties.

FIG. 1A is a schematic bottom view of a metal mask according to at least one embodiment of the present invention. Please refer to FIG. 1A , the metal mask 100 includes at least one working block 110 . In the embodiment shown in FIG. 1A , the metal mask 100 may include a plurality of working blocks 110 , while in other embodiments, the metal mask 100 may include only one working block 110 . Therefore, although the metal mask 100 of FIG. 1A includes a plurality of working blocks 110 , FIG. 1A does not limit the number of working blocks 110 included in the metal mask 100 .

The working blocks 110 can be arranged regularly. Taking FIG. 1A as an example, the working blocks 110 can be arranged in a row. In other embodiments, the working blocks 110 can also be arranged in an array. Therefore, FIG. 1A does not limit the arrangement of the working blocks 110 . In addition, the metal mask 100 also includes a peripheral blank area 120 , wherein the peripheral blank area 120 surrounds and surrounds the working areas 110 .

FIG. 1B is an enlarged schematic view of area 1B in FIG. 1A . Referring to FIG. 1B , each working block 110 includes a peripheral portion 111 and a central portion 112 , wherein the peripheral portion 111 surrounds and connects the central portion 112 . The peripheral portion 111 has a plurality of first openings H1, and the central portion 112 has a plurality of second openings H2, wherein the first openings H1 and the second openings H2 can be arranged in an array, and the first openings H1 and the second openings H2 Both dimensions may be substantially the same or similar. For example, the maximum difference between the apertures of the first opening H1 and the second opening H2 may be less than or equal to 0.3 μm. In addition, the peripheral blank area 120 may not have any openings, so as to maintain or enhance the structural strength of the metal mask 100 .

The metal mask 100 is suitable for making a patterned film layer, and can be applied to semiconductor manufacturing process or display panel manufacturing. For example, the metal mask 100 can be applied to a method of manufacturing an organic light emitting diode display panel, wherein the metal mask 100 is suitable for manufacturing a plurality of light-emitting layers, which may include physical vapor deposition (Physical Vapor Deposition) such as evaporation or sputtering. Vapor Deposition, PVD). During the process of vapor deposition or sputtering to form a light-emitting layer on the substrate to be coated (such as a glass plate), the metal mask 100 can block the coating material from the coating source and deposit the coating material on the first opening H1 and the surface of the plated substrate exposed by the second opening H2. In this way, these light-emitting layers can be respectively formed on the surface of the substrate to be coated exposed by the first opening H1 and the second opening H2.

The light emitting layer can be used as a subpixel, so the size of each of the first opening H1 and the second opening H2 can be equivalent to the size of a subpixel. In addition, the size of each working block 110 may be equivalent to the size of a display panel. For example, the size of the working block 110 may be equivalent to the size of a display panel in a smart phone or a tablet computer. According to different sizes of various display panels, the working block 110 can use different sizes to manufacture display panels (such as organic light emitting diode display panels).

Since the dimensions of the first opening H1 and the second opening H2 can be substantially the same or similar, for example, the maximum difference between the apertures of the first opening H1 and the second opening H2 can be less than or equal to 0.3 microns, so the first opening H1 is formed The light emitting layers in the second opening H2 have substantially the same or similar dimensions. Compared with the existing metal mask, the metal mask 100 of at least one embodiment of the present invention can produce a plurality of light-emitting layers with the same size or similar size, which is beneficial to manufacture a high-resolution display panel, thereby improving the resolution of the display panel.

In addition, the metal mask 100 may have a plurality of dotted planes 101s and a plurality of end points 101p, wherein the dotted planes 101s and the end points 101p are located on the same side of the metal mask 100 . Taking this embodiment as an example, both the point plane 101s and the end point 101p are located on the lower surface of the metal mask 100 . These dotted planes 101s are distributed in the peripheral portion 111 , but not in the peripheral blank area 120 , and these dotted planes 101s may not be distributed in the central portion 112 , as shown in FIG. 1B . In addition, it should be noted that FIG. 1B is not used to limit the distribution of the point planes 101s and the end points 101p.

At least one dotted plane 101s is located between four adjacent first openings H1. Taking FIG. 1B as an example, among the plurality of dotted planes 101s adjacent to the peripheral blank area 120 , each dotted plane 101s is located between four adjacent first openings H1 . In other words, the four adjacent first openings H1 surround a dotted plane 101s. In addition, the four adjacent first openings H1 surrounding the dotted plane 101s may be arranged in a 2×2 matrix.

FIG. 1C is an enlarged schematic view of area 1C in FIG. 1A . Referring to FIG. 1C , in this embodiment, at least one end point 101p is located between four adjacent second openings H2 . Taking FIG. 1C as an example, each end point 101p is located between four adjacent second openings H2. Referring to FIG. 1B and FIG. 1C , it can be seen from FIG. 1B and FIG. 1C that the endpoints 101 p are only distributed in the central portion 112 , but not distributed in the peripheral portion 111 and the peripheral blank area 120 .

FIG. 2 is a schematic cross-sectional view taken along the line 2-2 in FIG. 1B. Referring to FIG. 1B and FIG. 2 , the metal mask 100 has a first surface 101 and a second surface 102 , wherein the first surface 101 and the second surface 102 are opposite to each other. Taking FIG. 2 as an example, the first surface 101 and the second surface 102 may be the lower surface and the upper surface of the metal mask 100 respectively. Both the first openings H1 and the second openings H2 extend to the first surface 101 and the second surface 102 . In other words, both the first opening H1 and the second opening H2 are formed through the metal mask 100 , so the first surface 101 and the second surface 102 both expose the first opening H1 and the second opening H2 .

It can be seen from FIG. 2 that the thickness of the metal mask 100 is not uniform, and the thickness T1 of the peripheral portion 111 is significantly greater than the thickness T2 of the central portion 112 . In addition, in this embodiment, the thickness variation of the peripheral portion 111 in the same working block 110 may increase from the central portion 112 toward the peripheral blank block 120, as shown in FIG. 2 , wherein the thickness T1 shown in FIG. 2 It may be the minimum thickness of the peripheral portion 111 instead of the maximum thickness of the peripheral portion 111 .

In particular, FIG. 1A is a schematic bottom view of the metal mask 100 , so both FIG. 1B and FIG. 1C are partial bottom views of the metal mask 100 . That is to say, FIG. 1B is drawn looking at the metal mask 100 from the first surface 101 in FIG. 2 . It can be seen from FIG. 1B and FIG. 2 that the first surface 101 has these dotted planes 101s and these end points 101p, so these dotted planes 101s and these end points 101p are located on the lower surface of the metal mask 100 in FIG. 2 , that is, the first surface 101 , and the distance from the point plane 101s to the second surface 102 is greater than the distance from the end point 101p to the second surface 102 .

Each first opening H1 has a first annular rib F1 and a first sidewall S1 , wherein the first annular rib F1 is located between the first surface 101 and the second surface 102 . The first sidewall S1 is connected between the first surface 101 and the first annular rib F1, and the shape of the first sidewall S1 is annular, wherein the first annular rib F1 can extend along the edge of the first sidewall S1. .

From Figure 2, the apertures of the first openings H1 are not uniform, and the minimum aperture of the first openings H1 is substantially equal to the first annular rib F1 inner diameter. The first annular ribs F1 are substantially located on the reference plane RF1, wherein the reference plane RF1 is a virtual plane. In other words, the first annular ribs F1 are substantially coplanar. In addition, a first included angle A1 smaller than 90 degrees is formed between the first side wall S1 and the reference plane RF1 , as shown in FIG. 2 .

The structure and appearance of the second opening H2 are similar to those of the first opening H1. Specifically, each second opening H2 has a second annular rib F2 and a second sidewall S2 , wherein the second annular rib F2 is located between the first surface 101 and the second surface 102 . The second sidewall S2 is connected between the first surface 101 and the second annular rib F2, and the shape of the second sidewall S2 is also annular, wherein the second annular rib F2 can extend along the edge of the second sidewall S2.

From FIG. 2 , the diameters of the second openings H2 are also uneven, and the smallest diameter of the second openings H2 is substantially equal to the inner diameter of the second annular rib F2 . In addition, the second annular ribs F2 are substantially located on the reference plane RF1 , so the first annular ribs F1 and the second annular ribs F2 are substantially located on the same reference plane RF1 . In other words, the first annular ribs F1 and the second annular ribs F2 are substantially coplanar. In addition, a second included angle A2 is formed between the second side wall S2 and the reference plane RF1, which is smaller than the first included angle A1.

The first openings H1 and the second openings H2 can be formed through photolithography and wet etching, so the metal mask 100 can be a metal plate after photolithography and wet etching. Therefore, before performing wet etching, the opposite two surfaces of the metal plate are respectively masked by two layers. patterns, wherein these mask patterns can be photoresist patterns after development, and cover the peripheral blank area 120 and all the working areas 110, exposing only the first openings H1 and the second openings H2 to be formed later. Sheet metal surface. In other words, the mask patterns all have a plurality of through holes corresponding to the first opening H1 and the second opening H2 , wherein the through holes partially expose the surface of the metal plate (corresponding to the first surface 101 and the second surface 102 ).

Affected by the loading effect of wet etching, the etching rate of the area near the peripheral blank area 120 is significantly faster than the etching rate of the area far from the peripheral blank area 120 . Therefore, these through holes of each mask pattern are not designed to have the same size and size, wherein the through holes (corresponding to the first opening H1) near the peripheral blank area 120 have a smaller size, and the through holes far away from the peripheral blank area 120 have a smaller size. (corresponding to the second opening H2) has a larger size, so that the sizes of the first opening H1 and the second opening H2 affected by the load effect can be the same or similar, thereby reducing the apertures of the first opening H1 and the second opening H2 gap between.

In addition, due to the different sizes of the through holes of the mask pattern and the loading effect of wet etching, these dotted planes 101s will be distributed in the peripheral part 111, but not in the central part 112, and these end points 101p is distributed only in the central portion 112 but not in the peripheral portion 111 . Secondly, the changes of the first included angles A1 in the peripheral portion 111 also decrease gradually from the peripheral blank area 120 toward the central portion 112 , as shown in FIG. 2 .

In summary, the metal mask according to at least one embodiment of the present invention is suitable for making patterned film layers, for example, it is suitable for making multiple light-emitting layers of an OLED display panel. Moreover, the metal mask of at least one embodiment of the present invention A plurality of light-emitting layers with the same or similar size can be produced, which is beneficial to the production of a high-resolution display panel to improve the resolution of the display panel.

Although the present invention has been disclosed above with the embodiments, it is not intended to limit the present invention. Those with ordinary knowledge in the technical field of the present invention can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, this The protection scope of the invention shall be defined by the scope of the appended patent application.

1B, 1C: area

100: metal mask

101: First Surface

102: second surface

101p: endpoint

101s: Point Plane

110: work block

111: Peripherals

112: central part

120: peripheral blank block

A1: The first included angle

A2: Second included angle

F1: first annular bead

F2: second annular rib

H1: first opening

H2: second opening

RF1: Reference plane

S1: first side wall

S2: Second side wall

T1, T2: Thickness

FIG. 1A is a schematic bottom view of a metal mask according to at least one embodiment of the present invention. FIG. 1B is an enlarged schematic view of area 1B in FIG. 1A . FIG. 1C is an enlarged schematic view of area 1C in FIG. 1A . FIG. 2 is a schematic cross-sectional view taken along the line 2-2 in FIG. 1B.

100: metal mask

101: First Surface

102: second surface

101p: endpoint

101s: Point Plane

111: Peripherals

112: central part

A1: The first included angle

A2: Second included angle

F1: first annular bead

F2: second annular rib

H1: first opening

H2: second opening

RF1: Reference plane

S1: first side wall

S2: Second side wall

T1, T2: Thickness

Claims (6)

A metal mask has a first surface and a second surface opposite to the first surface, wherein the metal mask includes: at least one working block, including: a peripheral portion with a plurality of first openings; a central part, has a plurality of second openings, wherein the peripheral part surrounds and connects the central part, and the thickness of the peripheral part is greater than the thickness of the central part; and a peripheral blank block surrounds and connects to the at least one working block , wherein the first openings and the second openings both extend to the first surface and the second surface, the first surface has a plurality of dotted planes, and the dotted planes are distributed in the surrounding part, not Distributed in the peripheral blank area, wherein the first surface also has a plurality of endpoints, and these endpoints are only distributed in the central part, not distributed in the peripheral part and the peripheral blank area, wherein the dotted plane The distance to the second surface is greater than the distance from the end point to the second surface. The metal mask as claimed in claim 1, wherein the metal mask has a first surface and a second surface opposite to the first surface, and the first openings and the second openings all extend to the first surface A surface and the second surface, each of the first openings has: a first annular rib located between the first surface and the second surface; and a first side wall connected between the first surface and the of the first circular rib , wherein the first annular ribs are substantially located on a reference plane, and a first angle is formed between the first side wall and the reference plane, wherein the first angle is less than 90 degrees; each of the second openings It has: a second annular rib located between the first surface and the second surface; and a second side wall connected between the first surface and the second annular rib, wherein the second annular ribs The ribs are substantially located on the reference plane, and a second angle is formed between the second side wall and the reference plane, wherein the second angle is smaller than the first angle. The metal mask as claimed in claim 2, wherein the variation of the first included angles in the peripheral portion decreases gradually from the peripheral blank area toward the central portion. The metal mask as claimed in claim 1, wherein at least one end point is located between four adjacent second openings. The metal mask as claimed in claim 1, wherein at least one dotted plane is located between four adjacent first openings. The metal mask as claimed in claim 1, wherein the first openings and the second openings are arranged in an array.

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