KR102358270B1 - Mask for forming oled picture element and template for supporting mask and mask integrated frame - Google Patents

Abstract

The present invention relates to a mask for forming an OLED pixel, a mask support template and a frame-integrated mask. A mask according to the present invention is a mask for forming an OLED pixel on which a plurality of mask patterns are formed, the mask pattern comprising: a first mask pattern on an upper portion; and a lower second mask pattern, wherein the thickness of the first mask pattern is thicker than that of the second mask pattern, both sides of the first mask pattern are formed to have a concave curvature, and the upper width of the first mask pattern is larger than the lower width of the second mask pattern, and the lower width of the first mask pattern is smaller than the lower width of the second mask pattern.

Description

MASK FOR FORMING OLED PICTURE ELEMENT AND TEMPLATE FOR SUPPORTING MASK AND MASK INTEGRATED FRAME}

The present invention relates to a mask for forming an OLED pixel, a mask support template and a frame-integrated mask. More specifically, it relates to a mask for forming an OLED pixel, a mask support template, and a frame-integrated mask capable of clearly controlling the size and position of a mask pattern.

As a technology for forming pixels in the OLED manufacturing process, the FMM (Fine Metal Mask) method is mainly used to deposit an organic material at a desired location by attaching a thin metal mask to the substrate.

In the conventional mask manufacturing method, a thin metal plate to be used as a mask is prepared, and after PR coating on the thin metal plate, patterning is performed, or after PR coating to have a pattern, a mask having a pattern is manufactured by etching. However, it is not easy to form the mask pattern to be inclined in a tapered shape in order to prevent the shadow effect, and since a separate process is involved, there are problems in that the process time and cost increase, and the productivity is lowered. .

In the case of ultra-high-definition OLED, the current QHD image quality is 500-600 PPI (pixel per inch), with a pixel size of about 30-50 μm, and 4K UHD and 8K UHD high-definition are higher than this: ~860 PPI, ~1600 PPI, etc. has a resolution of Therefore, there is a need to develop a technology for precisely controlling the size of the mask pattern.

On the other hand, in the conventional OLED manufacturing process, a mask is manufactured in a stick shape, a plate shape, etc., and then the mask is welded and fixed to the OLED pixel deposition frame. For large-area OLED manufacturing, several masks can be fixed to the OLED pixel deposition frame, and in the process of fixing to the frame, tension is applied to make each mask flat. In the process of fixing several masks to one frame, there was a problem in that the masks were not well aligned with each other and between the mask cells. In addition, in the process of welding and fixing the mask to the frame, since the thickness of the mask film is too thin and has a large area, there is a problem in that the mask is sagged or twisted by a load.

As such, it is necessary to reduce the alignment error between cells by several μm in consideration of the pixel size of the ultra-high-definition OLED, and an error outside of this may lead to product failure, and thus the yield may be very low. Therefore, there is a need to develop a technology capable of preventing deformation such as sagging or twisting of the mask, and clarifying alignment, and a technology of fixing the mask to a frame.

Accordingly, the present invention has been devised to solve the problems of the prior art as described above, and it is to provide a mask for forming an OLED pixel, a mask support template, and a frame-integrated mask capable of precisely controlling the size of a mask pattern. The purpose.

The above object of the present invention is to provide a mask for forming an OLED pixel having a plurality of mask patterns formed thereon, the mask pattern comprising: an upper first mask pattern; and a lower second mask pattern, wherein the thickness of the first mask pattern is thicker than that of the second mask pattern, both sides of the first mask pattern are formed to have a concave curvature, and the upper width of the first mask pattern is greater than the lower width of the second mask pattern, and the lower width of the first mask pattern is smaller than the lower width of the second mask pattern, achieved by the mask.

Both side surfaces of the second mask pattern may be formed to have a convex curvature.

The sum of the shapes of the first mask pattern and the second mask pattern may represent an overall tapered shape or a reverse tapered shape.

An angle between an imaginary straight line extending from the upper edge of the first mask pattern to the lower edge of the first mask pattern and the lower surface of the mask may be less than 60° (greater than 0).

A lower width of the first mask pattern may be greater than 15.4 μm and smaller than 35 μm.

The thickness of the mask may be 5 μm to 20 μm.

And, the above object of the present invention is a template for supporting a mask for forming an OLED pixel, comprising: a template; a temporary adhesive formed on the template; and a mask adhered to the template with a temporary adhesive interposed therebetween and having a plurality of mask patterns formed thereon, wherein the mask pattern includes: an upper first mask pattern; and a lower second mask pattern, wherein the thickness of the first mask pattern is thicker than that of the second mask pattern, both sides of the first mask pattern are formed to have a concave curvature, and the upper width of the first mask pattern is greater than the lower width of the second mask pattern, and the lower width of the first mask pattern is smaller than the lower width of the second mask pattern, achieved by the mask support template.

A barrier insulating part may be further formed on the temporary adhesive part, and the mask may be adhered to the upper surface of the template with the temporary adhesive part and the barrier insulating part interposed therebetween.

Both side surfaces of the second mask pattern may be formed to have a convex curvature.

The first mask pattern and the second mask pattern are formed by wet etching, and when the second mask pattern is wet-etched, the etchant is etched in the lateral direction from the exposed portion of the barrier insulating part so that the lower width of the second mask pattern is the upper part It may be formed to be larger than the width.

In addition, the above object of the present invention is a frame-integrated mask in which a plurality of masks and a frame supporting the mask are integrally formed, the frame comprising: an edge frame portion including a hollow region; and a mask cell sheet portion having a plurality of mask cell regions and connected to the edge frame portion, wherein each mask on which the plurality of mask patterns are formed is connected to an upper portion of the mask cell sheet portion, and the mask pattern includes: 1 mask pattern; and a lower second mask pattern, wherein the thickness of the first mask pattern is thicker than that of the second mask pattern, both sides of the first mask pattern are formed to have a concave curvature, and the upper width of the first mask pattern is greater than the lower width of the second mask pattern, and the lower width of the first mask pattern is smaller than the lower width of the second mask pattern, achieved by the frame-integrated mask.

According to the present invention configured as described above, it is possible to precisely control the size and position of the mask pattern.

1 is a schematic diagram showing a process of attaching a conventional mask to a frame.
2 is a front view and a side cross-sectional view showing a frame-integrated mask according to an embodiment of the present invention.
3 is a schematic diagram illustrating a mask according to an embodiment of the present invention.
4 is a schematic diagram illustrating a process of manufacturing a mask support template by bonding a mask metal film on a template and forming a mask according to an embodiment of the present invention.
5 is a schematic diagram illustrating a conventional mask manufacturing process and an etching degree of a mask according to a comparative example.
6 to 7 are schematic views illustrating a manufacturing process of a mask according to an embodiment of the present invention.
8 is a schematic diagram illustrating an etching degree of a mask metal layer according to an embodiment of the present invention.
9 is a schematic diagram illustrating a process of manufacturing a mask support template according to an embodiment of the present invention.
10 is a schematic diagram illustrating an etching form of a mask metal layer according to a comparative example and an embodiment of the present invention.
11 is a schematic diagram illustrating a mask metal film according to an embodiment of the present invention.
12 is a graph illustrating a relationship between a hole and an open ratio according to an experimental example of the present invention.
13 is a schematic diagram illustrating a process of manufacturing a mask following FIG. 11 .
14 is a schematic diagram illustrating a principle of forming a mask pattern according to an embodiment of the present invention.
15 is a schematic diagram illustrating a mask according to an embodiment of the present invention.
16 to 18 are SEM photographs showing a mask according to an experimental example of the present invention.
19 is a schematic diagram illustrating a state in which a template is loaded onto a frame and a mask corresponds to a cell region of the frame according to an embodiment of the present invention.
20 is a schematic diagram illustrating a process of separating the mask and the template after attaching the mask to the frame according to an embodiment of the present invention.
21 is a schematic diagram illustrating a state in which a mask is attached to a cell region of a frame and an insulating part is removed according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0010] Reference is made to the accompanying drawings, which show by way of illustration specific embodiments in which the present invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the present invention. It should be understood that the various embodiments of the present invention are different but need not be mutually exclusive. For example, certain shapes, structures, and characteristics described herein with respect to one embodiment may be implemented in other embodiments without departing from the spirit and scope of the invention. In addition, it should be understood that the location or arrangement of individual components within each disclosed embodiment may be changed without departing from the spirit and scope of the present invention. Accordingly, the following detailed description is not intended to be taken in a limiting sense, and the scope of the present invention, if properly described, is limited only by the appended claims, along with all scope equivalents to those claimed. In the drawings, like reference numerals refer to the same or similar functions in various aspects, and the length, area, thickness, and the like may be exaggerated for convenience.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art can easily practice the present invention.

1 is a schematic diagram illustrating a process of attaching a conventional mask 10 to a frame 20 .

The conventional mask 10 is a stick-type or a plate-type, and the stick-type mask 10 of FIG. 1 can be used by welding and fixing both sides of the stick to the OLED pixel deposition frame. A plurality of display cells C are provided in the body of the mask 10 (or the mask film 11 ). One cell C corresponds to one display such as a smart phone. A pixel pattern P is formed in the cell C to correspond to each pixel of the display.

Referring to (a) of FIG. 1 , the stick mask 10 is loaded on the frame 20 in the form of a square frame in a flat state by applying tensile forces F1 to F2 in the long axis direction of the stick mask 10 . The cells C1 to C6 of the stick mask 10 are located in the blank area inside the frame 20 of the frame 20 .

Referring to FIG. 1 (b), after aligning while finely adjusting the tensile force (F1 to F2) applied to each side of the stick mask 10, a part of the side of the stick mask 10 is welded (W). Accordingly, the stick mask 10 and the frame 20 are interconnected. Figure 1 (c) shows a cross-section of the stick mask 10 and the frame interconnected.

Although the tensile forces F1 to F2 applied to each side of the stick mask 10 are finely adjusted, there is a problem in that the mask cells C1 to C3 are not well aligned with each other. For example, the distance between the patterns of the cells C1 to C6 is different from each other, or the patterns P are skewed, for example. Since the stick mask 10 has a large area including a plurality of cells C1 to C6 and has a very thin thickness of several tens of μm, it is easily sagged or twisted by a load. In addition, it is very difficult to check the alignment between the cells C1 to C6 in real time through a microscope while controlling the tensile force F1 to F2 to flatten all the cells C1 to C6. In order to prevent the mask pattern P having a size of several to several tens of μm from adversely affecting the pixel process of the ultra-high-definition OLED, it is preferable that the alignment error does not exceed 3 μm. This alignment error between adjacent cells is referred to as PPA (pixel position accuracy).

In addition to this, while connecting the plurality of stick masks 10 to one frame 20 , respectively, the alignment state between the plurality of stick masks 10 and between the plurality of cells C to C6 of the stick mask 10 . It is also a very difficult task to clarify, and the processing time according to alignment is inevitably increased, which is a significant reason for reducing productivity.

Meanwhile, after the stick mask 10 is connected and fixed to the frame 20 , the tensile forces F1 to F2 applied to the stick mask 10 may reversely act on the frame 20 . Such tension may slightly deform the frame 20 , and a problem of misalignment between the plurality of cells C to C6 may occur.

Accordingly, the present invention proposes a frame 200 and a frame-integrated mask that allows the mask 100 to form an integrated structure with the frame 200 . The mask 100 integrally formed with the frame 200 is prevented from being deformed such as sagging or twisting, and can be clearly aligned with the frame 200 .

2 is a front view [FIG. 2 (a)] and a side cross-sectional view [FIG. 2 (b)] showing a frame-integrated mask according to an embodiment of the present invention.

In this specification, the configuration of the frame-integrated mask will be briefly described below, but it can be understood that the structure and manufacturing process of the frame-integrated mask are included in the contents of Korean Patent Application No. 2018-0016186 as a whole.

Referring to FIG. 2 , the frame-integrated mask may include a plurality of masks 100 and one frame 200 . In other words, a plurality of masks 100 are attached to the frame 200 one by one. Hereinafter, for convenience of explanation, the mask 100 having a rectangular shape will be described as an example, but the masks 100 may be in the form of a stick mask having protrusions clamped on both sides before being attached to the frame 200 , and the frame 200 . ) after being attached to the protrusion can be removed.

A plurality of mask patterns P may be formed on each mask 100 , and one cell C may be formed on one mask 100 . One mask cell C may correspond to one display such as a smart phone.

The mask 100 may be made of a material such as invar, super invar, nickel (Ni), or nickel-cobalt (Ni-Co). The mask 100 may use a metal sheet produced by a rolling process or electroforming.

The frame 200 is formed so that a plurality of masks 100 can be attached thereto. The frame 200 is preferably made of a material such as Invar, Super Invar, Nickel, or Nickel-Cobalt having the same coefficient of thermal expansion as the mask in consideration of thermal deformation. The frame 200 may include an edge frame portion 210 having a substantially rectangular shape or a rectangular frame shape. The inside of the edge frame part 210 may have a hollow shape.

In addition, the frame 200 may include a plurality of mask cell regions CR, and may include a mask cell sheet unit 220 connected to the edge frame unit 210 . The mask cell sheet unit 220 may include an edge sheet unit 221 and first and second grid sheet units 223 and 225 . The edge sheet portion 221 and the first and second grid sheet portions 223 and 225 refer to partitioned portions of the same sheet, and they are integrally formed with each other.

The thickness of the edge frame portion 210 may be formed to a thickness of several mm to several cm thicker than the thickness of the mask cell sheet portion 220 . The mask cell sheet part 220 is thinner than the thickness of the edge frame part 210 , but may have a thickness of about 0.1 mm to 1 mm thicker than the mask 100 . The width of the first and second grid sheet parts 223 and 225 may be about 1 to 5 mm.

In the flat sheet, a plurality of mask cell regions CR: CR11 to CR56 may be provided except for regions occupied by the edge sheet part 221 and the first and second grid sheet parts 223 and 225 .

The frame 200 includes a plurality of mask cell regions CR, and each mask 100 may be attached such that one mask cell C corresponds to the mask cell region CR. The mask cell C corresponds to the mask cell region CR of the frame 200 , and a part or all of the dummy may be attached to the frame 200 (the mask cell sheet unit 220 ). Accordingly, the mask 100 and the frame 200 can form an integrated structure.

3 is a schematic diagram illustrating a mask 100 according to an embodiment of the present invention.

The mask 100 may include a mask cell C on which a plurality of mask patterns P are formed and a dummy DM around the mask cell C. The mask 100 may be manufactured from a metal sheet produced by a rolling process, electroplating, or the like, and one cell C may be formed in the mask 100 . The dummy DM corresponds to a portion of the mask film 110 (mask metal film 110 ) excluding the cell C, and includes only the mask film 110 or a predetermined dummy having a shape similar to the mask pattern P. The patterned mask layer 110 may be included. A part or all of the dummy DM may be attached to the frame 200 (the mask cell sheet unit 220 ) corresponding to the edge of the mask 100 .

The width of the mask pattern P may be formed to be smaller than 40 μm, and the thickness of the mask 100 may be formed to be about 5 to 20 μm. Since the frame 200 includes a plurality of mask cell regions CR: CR11 to CR56, the mask 100 having mask cells C: C11 to C56 corresponding to each of the mask cell regions CR: CR11 to CR56. ) may also be provided in plurality. In addition, a plurality of templates 50 supporting each of a plurality of masks 100 to be described later may be provided.

4 is a schematic diagram illustrating a process of manufacturing a mask support template by bonding the mask metal film 110 on the template 50 and forming the mask 100 according to an embodiment of the present invention.

Referring to FIG. 4A , a template 50 may be provided. The template 50 is a medium that can move the mask 100 in a supported state attached to one surface. The central part 50a may correspond to the mask cell C of the mask metal layer 110 , and the edge part 50b may correspond to the dummy DM of the mask metal layer 110 . The size of the template 50 may be a flat plate shape having the same area or a larger area than that of the mask metal layer 110 so that the mask metal layer 110 can be supported as a whole.

The template 50 may use a material such as wafer, glass, silica, heat-resistant glass, quartz, alumina (Al ₂ O ₃ ), borosilicate glass, zirconia, etc. have. As an example, the template 50 may use a material of BOROFLOAT ^® 33 having excellent heat resistance, chemical durability, mechanical strength, transparency, etc. among borosilicate glass. In addition, BOROFLOAT ^® 33 has a thermal expansion coefficient of about 3.3, which has a small difference between the invar mask metal film 110 and the invar mask metal film 110 , so that it is easy to control the mask metal film 110 .

A laser passing hole 51 may be formed in the template 50 so that the laser L irradiated from the upper portion of the template 50 can reach the welding portion WP of the mask 100 ; have. The laser passing hole 51 may be formed in the template 50 to correspond to the position and number of welds. Since a plurality of welding portions WP are disposed along a predetermined interval in the edge or dummy DM portion of the mask 100 , a plurality of laser passing holes 51 may be formed along a predetermined interval to correspond thereto. For example, since a plurality of welding portions WP are disposed along a predetermined interval on both sides (left/right) dummy DM portions of the mask 100, the laser passing hole 51 also includes the template 50 on both sides (left / A plurality may be formed along a predetermined interval on the right side).

The laser passing hole 51 does not necessarily correspond to the position and number of the welding parts WP. For example, welding may be performed by irradiating the laser L to only a portion of the laser passing holes 51 . In addition, some of the laser passing holes 51 that do not correspond to the welding portion WP may be used instead of the alignment mark when aligning the mask 100 and the template 50 . If the material of the template 50 is transparent to the laser (L) light, the laser passing hole 51 may not be formed.

A temporary adhesive portion 55 may be formed on one surface of the template 50 . The temporary adhesive portion 55 is formed by temporarily adhering the mask 100 (or the mask metal film 110 ′) to one surface of the template 50 until the mask 100 is attached to the frame 200 . It can be supported on top.

The temporary adhesive part 55 may use an adhesive or an adhesive sheet that can be separated by applying heat, or an adhesive or an adhesive sheet that can be separated by UV irradiation.

For example, the temporary adhesive part 55 may use liquid wax. As the liquid wax, the same wax used in the polishing step of a semiconductor wafer or the like may be used, and the type is not particularly limited. The liquid wax is a resin component for controlling adhesion, impact resistance, and the like with respect to holding power, and may include materials such as acrylic, vinyl acetate, nylon, and various polymers and solvents. For example, the temporary adhesive part 55 may use acrylonitrile butadiene rubber (ABR) as a resin component and SKYLIQUID ABR-4016 containing n-propyl alcohol as a solvent component. The liquid wax may be formed on the temporary adhesive portion 55 using spin coating.

The temporary adhesive part 55, which is a liquid wax, has a lower viscosity at a temperature higher than 85°C to 100°C, increases in viscosity at a temperature lower than 85°C, and can be partially solidified like a solid, so that the mask metal film 110' and the template 50 ) can be fixedly attached.

Next, referring to FIG. 4B , the mask metal layer 110 may be adhered on the template 50 . After the liquid wax is heated to 85° C. or higher and the mask metal film 110 is brought into contact with the template 50, the mask metal film 110 and the template 50 are passed between rollers to perform adhesion.

According to an embodiment, baking is performed on the template 50 at about 120° C. for 60 seconds to vaporize the solvent in the temporary adhesive part 55, and immediately, a mask metal film lamination process may be performed. . Lamination can be performed by loading the mask metal film 110 on the template 50 having the temporary adhesive part 55 formed on one surface and passing it between the upper roll at about 100° C. and the lower roll at about 0° C. have. As a result, the mask metal layer 110 may be in contact with the template 50 via the temporary adhesive portion 55 .

As another example, the temporary adhesive part 55 may use a thermal release tape. In the heat release tape, a core film such as a PET film is disposed in the center, a thermal release adhesive that can be thermally peeled is disposed on both sides of the core film, and a release film/release film is disposed on the outside of the adhesive layer. can Here, the pressure-sensitive adhesive layers disposed on both surfaces of the core film may have different temperatures at which they are peeled from each other.

According to one embodiment, with the release film/release film removed, the lower surface of the heat release tape (the lower second adhesive layer of the core film) is adhered to the template 50 , and the upper surface of the heat release tape (the core film) of the upper first adhesive layer) may be adhered to the mask metal layer 110 ′. Since the temperature at which the first adhesive layer and the second adhesive layer are peeled from each other is different, when the template 50 is separated from the mask 100 in FIG. The mask 100 may be detachable from the template 50 and the temporary adhesive part 55 .

On the other hand, the mask metal layer 110 may use a surface defect removal process and a thickness reduction process performed on one or both surfaces. The mask metal layer 110 may have a thickness of about 5 μm to 20 μm. After the mask metal layer 110 is adhered on the template 50 , a surface defect removal process and a thickness reduction process may be performed. On the other hand, the thickness reduction process may be performed only on the mask cell (C) portion. After the surface defect removal process such as CMP, an insulating part (not shown) such as a photoresist is formed only in the region corresponding to the welded part WP of the mask metal film 110 , or the mask metal film 110 is used as the template 50 . After forming an insulating part (not shown) such as a photoresist only in a region corresponding to the welding part WP of the mask metal film 110 in a state of being adhered and supported thereon, etching for reducing the thickness of the mask cell C part By performing the process, the welding portion WP is formed thick to form a step with the mask cell C portion, and at the same time, the surface of the mask cell C portion where the mask pattern P is to be formed can be made in a defect-free state. .

Next, referring to FIG. 4C , a patterned insulating portion 25 may be formed on the mask metal layer 110 . The insulating part 25 may be formed of a photoresist material using a printing method or the like.

Subsequently, the mask metal layer 110 may be etched. Methods such as dry etching and wet etching may be used without limitation, and as a result of the etching, a portion of the mask metal layer 110 exposed to the empty space 26 between the insulating portions 25 may be etched. The etched portion of the mask metal layer 110 constitutes the mask pattern P, and the mask 100 in which the plurality of mask patterns P are formed may be manufactured.

Next, referring to FIG. 4D , the manufacturing of the template 50 supporting the mask 100 may be completed by removing the insulating portion 25 .

Hereinafter, a process of manufacturing the mask 100 by forming the mask pattern P on the mask metal layer 110 will be described.

5 is a schematic diagram illustrating a conventional mask manufacturing process [(a) to (c)] and an etching degree [(d)] of a mask according to a comparative example.

Referring to FIG. 5 , a conventional mask manufacturing process is performed only by wet etching.

First, a patterned photoresist M may be formed on a planar film 110 ′ as shown in FIG. 5A . Next, wet etching (WE) is performed through the space between the patterned photoresists M as shown in FIG. 5B . After the wet etching WE, a partial space of the layer 110 ′ may be penetrated to form a mask pattern P′. Next, when the photoresist M is washed, the production of the film 110 ′ on which the mask pattern P′ is formed, that is, the mask 100 ′ can be completed.

As shown in FIG. 5C , the conventional mask 100' has a problem in that the sizes of the mask patterns P' are not uniform. Since wet etching (WE) is isotropically performed, the etched shape tends to have an approximately arc shape. In addition, since it is very difficult to perform the same etch rate on each part in the wet etching (WE) process, the widths R1', R1″, R1″' of the penetrated pattern after the layer 110' is penetrated. ) may be different from each other. In particular, in a pattern in which an undercut (UC) occurs a lot, not only the lower width R1″ of the mask pattern P′ but also the upper width R2″ may be formed to be wide, and in a pattern in which the undercut UC is less generated, The lower widths R1' and R1"' and the upper widths R2' and R2"' may be formed to be relatively narrow.

As a result, the conventional mask 100' has a problem in that the sizes of the respective mask patterns P' are not uniform. In the case of ultra-high-definition OLED, the current QHD image quality is 500-600 PPI (pixel per inch), with a pixel size of about 30-50 μm, and 4K UHD and 8K UHD high-definition are higher than this: ~860 PPI, ~1600 PPI, etc. Since it has a resolution of

Referring to FIG. 5D , since wet etching is performed isotropically, the etched shape tends to have an approximately arc shape. In addition, in the wet etching process, it is difficult for the etching rate to be exactly the same at each part, and when the mask pattern is formed as the mask metal layer 110 is penetrated by performing wet etching only once, the deviation may be greater. . For example, although the mask pattern 111 and the mask pattern 112 have a difference in wet etching rates, the difference in upper width (undercut) is not so great. However, the lower width PD1 of the mask metal film 110 penetrated by the formation of the mask pattern 111 and the lower width PD2 of the mask metal film 110 penetrated by the formation of the mask pattern 112 are The difference becomes much larger than the difference in the upper width. This is a result of wet etching being performed isotropically. In other words, since the width determining the size of the pixel is the lower width PD1 and PD2 rather than the upper width of the mask patterns 111 and 112, the lower width is performed by performing wet etching in a different way than performing one wet etching. A method of controlling (PD1, PD2) is considered.

Accordingly, according to the present invention, by performing a plurality of wet etching in one direction, it is possible to improve the pattern precision of the mask in the wet etching process.

6 to 7 are schematic views illustrating a manufacturing process of a mask according to an embodiment of the present invention.

Referring to FIG. 6A , first, a mask metal layer 110 that is a metal sheet may be provided. The mask metal layer 110 is produced by rolling, electroplating, etc., and the material of the mask metal layer 110 is invar, super invar, nickel (Ni), nickel-cobalt (Ni). -Co) and the like.

Next, a patterned first insulating part M1 may be formed on one surface (top surface) of the mask metal layer 110 . The first insulating part M1 may be formed of a photoresist material using a printing method or the like. The insulating parts M1, M2, and M3 of FIGS. 6 to 7 are insulating parts used to form the mask pattern P, and correspond to the insulating part 25 to be described later in FIG. 9, and are separated from the barrier insulating part 23 make it clear that they are separated

The first insulating part M1 may be made of a black matrix photoresist or a photoresist material having a metal coating film formed thereon. Alternatively, the first insulating part M1 may be made of a photoresist material having a different property from that of the second insulating part M2 or the third insulating part M3 to be described later, preferably an epoxy-based photoresist material. . The black matrix photoresist may be a material including a black matrix resin used to form a black matrix of a display panel. A black matrix photoresist may have a greater light blocking effect than a general photoresist. In addition, a photoresist having a metal coating film formed thereon may also have a large effect of blocking light irradiated from the upper portion by the metal coating film. The first insulating part M1 may be made of a positive type photoresist material.

Next, referring to FIG. 6B , the first mask pattern P1 ′ by a predetermined depth may be formed by wet etching WE1 on one surface (top surface) of the mask metal layer 110 . The first mask pattern P1 ′ may be formed in a substantially circular arc shape without penetrating the mask metal layer 110 , but in the present invention described below with reference to FIG. 11 , the first mask pattern (main etch pattern P1-2) corresponding to] is characterized in that it includes a hole SN. In FIG. 6 , the hole SN is excluded for convenience of description of the process. That is, the depth value of the first mask pattern P1 ′ excluding the hole SN may be less than the thickness of the mask metal layer 110 .

Since the wet etching WE1 has an isotropic etching characteristic, the width R2 of the first mask pattern P1 does not have the same width as the distance R3 between the patterns of the first insulating portion M1, and the first insulation It may have a width wider than the interval R3 between the patterns of the portion M1. In other words, since undercuts UC are formed under both sides of the first insulating part M1, the width R2 of the first mask pattern P1' is equal to the interval between the patterns of the first insulating part M1 ( R3) may be larger than the width in which the undercut UC is formed.

Next, referring to FIG. 6C , a second insulating part M2 may be formed on one surface (top surface) of the mask metal layer 110 . The second insulating part M2 may be formed of a photoresist material using a printing method or the like. Since the second insulating part M2 must be left in a space where the undercut UC, which will be described later, is formed, it is preferable that the second insulating part M2 is made of a positive type photoresist material.

Since the second insulating portion M2 is formed on one surface (top surface) of the mask metal layer 110 , a portion may be formed on the first insulation portion M1 , and a portion may be filled in the first mask pattern P1 . have.

The second insulating part M2 may use a photoresist diluted in a solvent. When a high-concentration photoresist solution is formed on the mask metal layer 110 and the first insulating part M1 , a portion of the first insulating part M1 is dissolved by reacting with the photoresist of the first insulating part M1 . it might be Thus, in order not to affect the first insulating part M1 , the second insulating part M2 may be diluted with a solvent to lower the concentration of the photoresist.

Next, referring to FIG. 7D , a portion of the second insulating part M2 may be removed. For example, a portion of the second insulating part M2 may be removed by volatilizing by performing baking. By baking, the solvent of the second insulating portion M2 is volatilized, leaving only the photoresist component. Thus, the second insulating portion M2 ′ may remain as thin as a coated layer on the exposed portion of the first mask pattern P1 and the surface of the first insulating portion M1 . The thickness of the remaining second insulating part M2' is less than several μm to such an extent that it does not affect the pattern width R3 of the first insulating part M1 or the pattern width R2 of the first mask pattern P1. It is preferable that the degree

Next, referring to FIG. 7E , exposure L may be performed on one surface (top surface) of the mask metal layer 110 . During exposure L on the upper part of the first insulating part M1 , the first insulating part M1 may act as an exposure mask. Since the first insulating part M1 is made of a black matrix photoresist or a photoresist material having a metal coating film formed thereon, a light blocking effect may be excellent. Thus, the second insulating part M2" (refer to FIG. 7(f) ) positioned vertically below the first insulating part M1 may not be exposed L, and the remaining second insulating part M2' may not be exposed. may be exposed (L).

Next, referring to (f) of FIG. 7 , when developing after exposure (L), a portion of the second insulating part M2″ that is not exposed (L) remains, and the remaining second insulating part M2′ is Since the second insulating part M2' is a positive type photoresist, the exposed portion L may be removed. It may correspond to the space in which the undercut UC is formed (refer to step (b) of FIG. 6) on both lower sides of M1).

Next, referring to FIG. 7G , wet etching WE2 may be performed on the first mask pattern P1 of the mask metal layer 110 . The wet etching solution may penetrate into the space between the patterns of the first insulating portion M1 and the space of the first mask pattern P1 to perform the wet etching WE2 . The second mask pattern P2 may be formed through the mask metal layer 110 . That is, it may be formed from the lower end of the first mask pattern P1 through the other surface of the mask metal layer 110 .

In this case, the second insulating portion M2″ remains in the first mask pattern P1. The remaining second insulating portion M2″ may serve as a wet etching mask. That is, the second insulating portion M2″ masks the etchant to prevent the etchant from being etched in the lateral direction of the first mask pattern P1 and to be etched in the lower surface direction of the first mask pattern P1.

Since the second insulating part M2" is disposed in the undercut UC space vertically below the first insulating part M1, the pattern width of the second insulating part M2" is substantially equal to that of the first insulating part M1. It corresponds to the pattern width R3 of Accordingly, the second mask pattern P2 is similar to that obtained by performing the wet etching WE2 on the gap R3 between the patterns of the first insulating portion M1 . Accordingly, the width R1 of the second mask pattern P2 may be narrower than the width R2 of the first mask pattern P1.

Since the width of the second mask pattern P2 defines the width of the pixel, the width of the second mask pattern P2 is preferably smaller than 35 μm. In addition, if the thickness of the second mask pattern P2 is too thick, it is difficult to control the width R1 of the second mask pattern P2, the uniformity of the widths R1 is lowered, and the shape of the mask pattern P is changed. Since there may be a problem that the tapered/reverse tapered shape does not appear as a whole, the thickness of the second mask pattern P2 is preferably smaller than the thickness of the first mask pattern P1 . The thickness of the second mask pattern P2 is preferably as close to 0 as possible, and considering the size of the pixel, for example, the thickness of the second mask pattern P2 is preferably about 0.5 to 3.0 μm, and 0.5 to 2.0 μm is more preferable.

The sum of the shapes of the successive first and second mask patterns P1 and P2 may constitute the mask pattern P.

Next, referring to FIG. 7H , the manufacturing of the mask 100 may be completed by removing the first insulating portion M1 and the second insulating portion M2″. First and second mask patterns Since (P1, P2) is formed including the inclined surface and the height of the second mask pattern P2 is formed to be very low, when the shapes of the first mask pattern P1 and the second mask pattern P2 are combined, the overall It may exhibit a tapered shape or a reverse tapered shape.

Meanwhile, steps (b2) and (b3) may be further performed between steps (b) and (c) of FIG. 6 .

Referring to FIG. 6B , a third insulating part M3 may be formed in the first mask pattern P1 ′. A third insulating part M3 may be formed on at least a portion of the first mask pattern P1 ′ exposed between the first insulating parts M1 . For example, the third insulating part M3 has a width R3 within the interval between patterns of a pair of adjacent first insulating parts M1 , and is formed on the first mask pattern P1'. can be formed.

For the convenience of exposure, it is preferable to use a negative type photoresist material for the third insulating part M3. When a negative type photoresist is filled in the first mask pattern P1 ′ and exposure is performed thereon, the first insulating part M1 acts as an exposure mask for the third insulating part M3 , and the first insulating part M1 ' Only the third insulating portion M3 exposed in the portion between the patterns of the portion M1 may remain. Accordingly, as shown in FIG. 6C , a third insulating portion M3 having a width R3 may be formed on the first mask pattern P1 ′.

Next, referring to (b3) of FIG. 6 , the first mask pattern P1' may be further wet etched (WE3). Since the third insulating portion M3 is formed on a portion of the first mask pattern P1', the first mask pattern P1' may be etched laterally without being further etched downward. Accordingly, the width of the first mask pattern P1' may be greater than that of R2 (P1' -> P1).

The reason for performing steps (b2) and (b3) of FIG. 6 will be described in detail as follows.

If steps (b2) and (b3) of FIG. 6 are omitted and a second mask pattern P2 to be described later in FIG. 7 is formed immediately after the first mask pattern P1' is formed, the mask pattern P' : It is difficult to lower the taper angle of P1', P2). Due to the characteristics of the isotropic etching process of the first mask pattern P1', it is difficult to have a low side angle (the angle between the horizontal plane and the side surface of the mask pattern), and the angle exceeds 60° or approaches vertical. Even after performing twice, the angle of the mask patterns P': P1' and P2 may exceed 70°. As a whole, it is effective to prevent a shadow effect when the angle between the side surface and the horizontal plane of the mask pattern P is formed to be about 30° to 70°. There is a problem that is difficult to form.

In addition, in order to ensure that the surface of the mask pattern P is not rough and has a uniform shape, a wet etching process needs to be performed within a short time. However, if the wet etching process is performed within a short time, it is difficult to show a low side angle of the first mask pattern P1 ′. As a result, if the wet etching process time is increased so that the side angle of the first mask pattern P1' appears low, the surface of the mask pattern P becomes rough and the shape is non-uniform.

Accordingly, the third insulating portion M3 is further formed in the first mask pattern P1' to prevent the lower portion of the first mask pattern P1' from being etched, and the lateral direction of the first mask pattern P1' As the wet etching WE3 is further performed (P1' -> P1), there is an effect that the angle between the side surface of the first mask pattern P1 and the horizontal plane can be lowered (a1 -> a2). Since the first mask pattern P1 is formed by dividing the wet etching into two, it is not necessary to maintain the etching process for a long time, so that the surface shape of the mask pattern P can be uniformly formed.

After the wet etching WE3 is further performed to form the first mask pattern P1 in which the angle a2 between the side surface and the horizontal plane is lowered, the third insulating portion M3 may be removed.

8 is a schematic diagram illustrating an etching degree of the mask metal layer 110 according to an embodiment of the present invention.

The process up to (a) of FIG. 8 is the same as the process described in (a) to (b) of FIG. 6 . However, in (a) of FIG. 8 , the first mask pattern P1-1 and the first mask pattern P1-2 showing a difference in etching degree in the wet etching WE1 through the first insulating portion M1 are shown. Compare and explain.

Referring to (a) of FIG. 8 , the etching is performed like the first mask pattern P1-1 and the first mask pattern P1-2 depending on the portion even by the same wet etching WE1-1 and WE1-2. There may be differences in degree. The pattern width R2-1 of the first mask pattern P1-1 is smaller than the pattern width R2-2 of the first mask pattern P1-2, and the pattern width R2-1 and R2-2 is smaller than the pattern width R2-2 of the first mask pattern P1-2. ) may be a difference to the extent that it adversely affects the resolution of the pixel.

Next, referring to FIG. 8(b), after performing the process described in FIGS. 6(c) to 7(f), second insulation is provided in the vertical lower space of the first insulating part M1, respectively. It can be seen that the portions M2″-1 and M2″-2 are formed. Due to a difference in the size of the undercut space under the first insulating part M1, the sizes of the second insulating parts M2"-1 and M2"-2 may be different. Although the size in which the second insulating part M2"-2 is formed is larger than that of the second insulating part M2"-1, the pattern widths of the second insulating parts M2"-1 and M2"-2 may be the same. have. The pattern width R3 of each of the second insulating parts M2"-1 and M2"-2 may be the same as that of the first insulating part M1.

Next, referring to FIG. 8C , wet etching WE2 is performed using each of the second insulating portions M2″-1 and M2″-2 as a wet etching mask, and the mask metal layer is (110) can be penetrated. The deviation of the widths R1-1 and R1-2 of the second mask patterns P2-1 and P2-2 formed as a result of this is the width R2- of the first mask patterns P1-1 and P1-2. 1, it can be significantly smaller than the deviation of R2-2). This includes first wet-etching the mask metal layer 110 to the depth of the first mask patterns P1-1 and P1-2, and secondarily performing wet etching with respect to the remaining thickness of the mask metal layer 110, At the same time, the pattern widths of the second insulating portions M2″-1 and M2″-2 subjected to the wet etching secondarily are substantially the same as the pattern widths of the first insulating portions M1 subjected to the wet etching first. Because.

As described above, in the method for manufacturing a mask, the mask pattern P can be formed to a desired size by performing wet etching a plurality of times. In particular, as a portion of the second insulating portion M2 ″ is left, the wet etching WE2 forming the second mask pattern P2 is performed by the wet etching WE1 and WE2 forming the first mask pattern P1 . Since it is performed for a smaller width and a thinner thickness, there is an advantage in that it is easy to control the width R1 of the second mask pattern P2. In addition, since an inclined surface can be formed by wet etching, a shadow effect is obtained. It is possible to implement a mask pattern P that prevents .

9 is a schematic diagram illustrating a process of manufacturing a mask support template according to an embodiment of the present invention.

In the present invention, the process of forming the mask pattern P of FIGS. 6 to 7 may be performed after the mask metal layer 110 is adhered to the template 50 . Since the processes of (a), (b), and (c) of FIG. 9 correspond to the processes of (b), (c), and (d) of FIG. 4 , descriptions of the same parts will be omitted.

Referring to FIG. 9A , the mask metal layer 110 may be adhered on the template 50 with the temporary adhesive part 55 interposed therebetween. However, it is necessary to prevent the etching solution from entering the interface between the mask metal film 110 and the temporary adhesive part 55 to damage the temporary adhesive part 55/template 50 and to generate an etching error of the mask pattern P. there is Accordingly, the mask metal layer 110 may be adhered to the upper surface of the template 50 while the barrier insulating part 23 is formed on one surface of the mask metal layer 110 . That is, the surface of the mask metal layer 110 on which the barrier insulating portion 23 is formed may be opposite to the upper surface of the template 50 . The mask metal layer 110 and the template 50 may be bonded to each other with the barrier insulating part 23 and the temporary adhesive part 55 interposed therebetween.

The barrier insulating part 23 may be formed on the mask metal layer 110 using a printing method or the like using a photoresist material that is not etched by an etchant. In addition, in order to preserve the original shape even in the wet etching process performed a plurality of times, the barrier insulating part 23 may include at least one of a curable negative photoresist and a negative photoresist including an epoxy. As an example, baking of the temporary adhesive part 55 using an epoxy-based SU-8 photoresist or black matrix photoresist, baking of the second insulating part M2 (see FIG. 7(d)), etc. It is desirable to make it harden together in the process of

Next, referring to FIG. 9B , a patterned insulating portion 25 may be formed on the mask metal layer 110 . The insulating part 25 may correspond to the insulating part 25 of FIG. 5D or the insulating parts M1, M2, and M3 of FIGS. 6 to 7 .

Subsequently, the mask metal layer 110 may be etched. The mask pattern P may be formed using the etching method of FIG. 4C or the etching method of FIGS. 6 to 7 .

Next, referring to FIG. 9C , the manufacturing of the template 50 supporting the mask 100 may be completed by removing the insulating portion 25 . A mask support template including the mask 100/barrier insulating part 23/temporary adhesive part 55/template 50 may be manufactured.

The reason for manufacturing the mask support template by further including the barrier insulating part 23 will be described in more detail below.

10 is a schematic diagram illustrating an etching form of a mask metal layer according to a comparative example and an embodiment of the present invention.

6 to 7 , it is advantageous to etch only one surface (eg, the top surface) of the mask metal layer 110 . If etching is performed on both surfaces at the same time, the thickness of the mask metal layer 110 may become non-uniform, and it may be difficult to implement a desired shape of the mask pattern P. Since wet etching (WE) is performed on one surface and wet etching is performed a plurality of times, it is very important that the etchant does not leak to the other surface (eg, the lower surface) of the mask metal layer 110 .

10 (a) is a comparative example of a form in which the mask metal film 110 is bonded to the template 50 through the temporary bonding portion 55 without the barrier insulating portion 23 . As described above with reference to FIG. 7G , the first mask patterns P1: P1-1 and P1-2 are formed to be thick, and the width of the second mask pattern P2 is used to define the pixel width. Therefore, the thickness of the second mask pattern P2 is preferably as close to zero as possible.

Therefore, it is preferable to form the first mask pattern P1 as deep as possible, but even by the same wet etching (WE1-1, WE1-2), the first mask pattern P1-1 and the first mask pattern ( P1-2'), there may be a difference in the degree of etching. Like the first mask pattern P1 - 2 ′ on the right of FIG. 10A , there may be a case in which the etch WE1 - 2 is etched enough to form the hole SN.

In this case, there may be a problem in that the temporary adhesive portion 55 exposed at the lower portion is also damaged (55 -> 55') by the wet etching WE1-2. In addition to damage to the temporary adhesive part 55 ′, damage to the template 50 may also occur.

In addition, when the etchant enters between the interface between the damaged temporary adhesive part 55' and the mask metal layer 110 (WE1-2'), as the lower portion of the first mask pattern P1 is further etched, the size of the pattern is increased. There may be a problem of forming excessively large or causing local irregular defects.

Accordingly, in the present invention, the first barrier insulating part 23 is further interposed between the mask metal layer 110 and the temporary adhesive part 55 to perform the first wet etching process WE1: WE1-1 and WE1-2. Even if the mask pattern P1 - 2 is formed to penetrate the mask metal layer 110 , it is possible to prevent the etchant from entering the lower surface of the mask metal layer 110 .

Since the barrier insulating part 23 includes at least one of a curable negative photoresist, a negative photoresist including an epoxy, and a black matrix photoresist, not only the first wet etching WE1 but also the second and third Even if subsequent etching processes such as wet etching (WE2, WE3) are further performed, it can withstand the etchant without melting. Accordingly, even if the first mask pattern P1 - 2 passes through the mask metal layer 110 , the pattern width is not further enlarged and can be maintained at a level corresponding to the width of the first insulating part M1 .

11 is a schematic diagram illustrating a mask metal film according to an embodiment of the present invention. Fig. 11 (a) is a schematic plan view, Fig. 11 (b) is a side cross-sectional schematic view of (a). 11 illustrates that a circular mask pattern P1 is formed on a planar basis, however, it should be noted that the mask pattern P1 may be formed in various shapes such as a quadrangle and a polygon.

As described above in FIG. 10 , the first mask patterns P1: P1-1 and P1-2 are preferably formed as deep as possible, but only the minimum thickness by accurately controlling the etching rates WE1-1 and WE1-2. Leaving behind is not an easy process. Accordingly, according to the present invention, the etching WE1-2 may be performed until the hole SN is formed as in the right first mask pattern P1-2 of FIG. 11A . Accordingly, after the first wet etching WE1: WE1-1, WE1-2 (step (b) of FIG. 6 ) is finished, the mask metal layer 110 may be formed so that at least a portion of the plurality of first mask patterns P1 is formed as a mask. A hole SN passing through the lower surface of the metal layer 110 may be included. There is an effect that the depth of the first mask pattern P1 can be formed to be the deepest when the hole SN is formed immediately before and after the hole SN is formed. Even when the hole SN is formed, since the barrier insulating part 23 is formed on the template 50 , it is possible to prevent the etchant from leaking through the hole SN.

Since the first mask pattern P1 is formed by the first wet etching WE1, it exhibits an isotropic etching characteristic, and the width of the mask metal layer 110 becomes narrower from the upper surface to the lower surface and has a concave curvature shape. can The upper width of the first mask pattern P1 may be greater than the interval R3 between the patterns of the first insulating part M1 due to the formation of undercuts under both sides of the first insulating part M1 . Accordingly, the hole SN at the lowermost end of the first mask pattern P1 is formed within the gap between the first insulating part M1 and the adjacent first insulating part M1 (or the pattern of the first insulating part M1). within the interval] may be located in the vertical region. The interval between the patterns of the first insulating part M1 may be set to about 20 μm to 30 μm in consideration of the lower width of the final mask pattern P.

However, if the size of the hole SN becomes too large, the second insulating part M2 is formed, which is a subsequent process, and the target to be etched is lost when the second wet etching WE2 is performed. It may be difficult to form the mask pattern P2 . In addition, the temporary adhesive part 55 and the barrier insulating part 23 of the template 50 may be affected by the etchant WE1-2 ′ flowing through the large hole SN. Accordingly, it is necessary to limit the size of the hole SN. When the upper width of the final mask pattern P is set to about 40 µm and the lower width to about 25 µm, the width of the hole SN is preferably less than about 15.4 µm (greater than 0), and less than about 15 µm ( greater than 0) is more preferable.

12 is a graph illustrating a relationship between a hole and an open ratio according to an experimental example of the present invention. FIG. 12 (a) shows the aperture ratio compared to the target size of the hole SN, and FIG. 12 (b) shows the maximum width of the hole SN compared to the aperture ratio. Here, the aperture ratio may be understood to mean the area of the hole SN compared to the area of the first mask pattern P1 on a plane (the surface of the mask metal layer). The aperture ratio can be quantified through a transmitted black-and-white image.

Referring to FIG. 12 (a) , it can be seen that the width variation of the hole SN is very large in the section where the hole SN starts to be formed (the aperture ratio exceeds 0). This is because, as described above in FIG. 5( d ), the rate of etching in the width direction (PD1 -> PD2) is greater than the degree of etching in the downward direction by performing the wet etching isotropically. Therefore, it is necessary to stably set the aperture ratio before the width fluctuation of the hole SN increases.

Referring to FIG. 12 ( b ) , it can be seen that the width of the hole SN is rapidly changed in the section where the opening ratio is 0 to 0.3%. Accordingly, in order to set the maximum width of the hole SN to about 15 μm, the aperture ratio may be 0 to 0.3%, more preferably 0 to 0.1%.

Again, referring to FIG. 11 , the angle a formed by the first mask pattern P1 with the horizontal plane may be less than 60° (greater than 0). From another point of view, the angle a formed between the imaginary straight line extending from the hole SN to the upper edge of the first mask pattern P1 and the lower surface of the mask metal layer 110 may be less than 60° (greater than 0). have. In order to prevent a shadow effect, the angle between the side surface and the horizontal plane of the final mask pattern P should be formed to be about 30° to 70°, and when the second mask pattern P2 is further formed in a subsequent process, the angle (a) becomes more Since it may become large, it is preferable that the angle a formed between the first mask pattern P1 (the first mask pattern P1 ) and the horizontal plane is smaller than this.

13 is a schematic diagram illustrating a process of manufacturing the mask 100 following FIG. 11 .

Referring to FIG. 13A , after the first mask pattern P1 including the hole SN is formed, the second insulating portion M2″ may be formed on the side surface of the first mask pattern P1. Yes (refer to Fig. 7(f) ) Then, a wet etch WE2 may be performed on the first mask pattern P1. The wet etchant may be applied to the space between the patterns of the first insulating portion M1 and the first The wet etching WE2 may be performed by penetrating into the space of the mask pattern P1 . The second insulating portion M2 ″ masks the etchant to prevent the etchant from being etched in the lateral direction of the first mask pattern P1 . and etched toward the lower surface of the first mask pattern P1.

Referring to FIG. 13B , a second mask pattern P2 may be formed to penetrate the mask metal layer 110 . That is, the second mask pattern P2 may be formed while passing through the other surface of the mask metal layer 110 from the lower end of the first mask pattern P1 with a width greater than that of the hole SN.

In this case, the second mask pattern P2 may not be formed with concave curvatures on both sides as described above with reference to FIGS. 7 ( g ) and 7 ( h ). Due to the fact that the first mask pattern P1 has the hole SN and the barrier insulating part 23 is present under the mask metal layer 110 , the shape of the second mask pattern P2 may appear like this. can

14 is a schematic diagram illustrating a principle of forming a mask pattern according to an embodiment of the present invention. The reason why the second mask pattern P2 appears as shown in FIG. 13(b) will be described.

Referring to FIG. 14 (a) , the etchant penetrates between the second insulating portions M2″. Due to the formation of the hole SN, the exposed portion of the mask metal film 110 around the hole SN is very In addition, the exposed portion of the mask metal layer 110 has less curvature than the unexposed portion and has a more horizontal shape. Accordingly, the portion surrounding the hole SN is thin It is etched to a thickness (WE2') and removed first, and it is reviewed that etching of the side can be further performed as the side of the removed part is exposed. Alternatively, a point having a higher etch rate in the lateral direction (PD1 -> similar to PD2 in FIG. 5(d)) may also work.

As another aspect, referring to FIG. 14 ( b1 ) , the second insulating part M2 ″ ′ does not necessarily correspond to a vertical lower position of the first insulating part M1 , but along the side surface of the first mask pattern P1 . When the exposure L is performed in FIG. 7E , the second exposed through the gap between the first insulating portions M1 due to the depth of the first mask pattern P1 At least a corner portion of the 2 insulating portions M″′ may not be exposed. Accordingly, this portion remains and the second insulating portion M2″′ may be formed to a lower position. Alternatively, exposure and development are intentionally performed to more precisely control the size of the second mask pattern P2. It can be made to have the shape of the second insulating part M2"' through the

Subsequently, a portion of the mask metal layer 110 exposed at intervals between the second insulating portions M2″′ formed to a lower position along the side surface of the first mask pattern P1 may be wet-etched (WE2).

Referring to FIG. 14 (b2) , an undercut shape may appear in the mask metal layer 110 in the vertical lower portion of the second insulating part M2"' due to isotropic etching. The second insulating part M2"' ) and the barrier insulating part 23 is small, so it is considered that the etchant can flow more into the lower part than the upper part or the middle part of the mask metal film 110 under the second insulating part M2"' Thus, the undercut of the mask metal layer 110 under the second insulating portion M2"' may not have a concave curvature, but may have a convex curvature or a shape close to a straight line.

Of course, all of the principles of (a), (b1), (b2) of FIG. 14 may be applied.

15 is a schematic diagram illustrating a mask according to an embodiment of the present invention.

15 , the mask pattern P includes an upper first mask pattern P1 and a lower second mask pattern P2, and the thickness of the first mask pattern P1 is It may be thicker than the thickness of P2).

The first mask pattern P1 is formed to have concave curvature on both sides as a result of iso-etching. The second mask pattern P2 may have a convex curvature or a shape close to a straight line without concave curvature on both sides thereof.

Of course, the upper width D1 of the first mask pattern P1 is greater than the lower width D2 of the second mask pattern P2. In addition, the lower width D3 of the first mask pattern P1 (or the upper width D3 of the second mask pattern P2 ) may be smaller than the lower width D2 of the second mask pattern P2 . . In FIG. 11 , the width of the hole SN of the first mask pattern P1 is set to be smaller than 15.4 μm, and the lower width D2 of the second mask pattern P2 is set to be smaller than 35 μm, so the first mask pattern It is preferable that the lower width D3 of (P1) (or the upper width D3 of the second mask pattern P2) is greater than 15.4 µm and smaller than 35 µm. Accordingly, the shape of the side cross-section of the mask pattern P may have a shape similar to that of a water droplet falling on the floor.

The angle ta formed between the imaginary straight line extending from the upper edge of the first mask pattern P1 to the lower edge of the first mask pattern P1 and the lower surface of the mask may be less than 60° (more than 0), preferably may be less than 55°. Since both sides of the second mask pattern P2 have a convex curvature, an imaginary straight line must be arranged to contact the lower edge of the first mask pattern P1 rather than the lower edge of the second mask pattern P2 . Accordingly, the sum of the shapes of the first mask pattern P1 and the second mask pattern P2 , that is, the shape of the mask pattern P may exhibit a tapered shape or an inverse tapered shape as a whole.

16 to 18 are SEM photographs showing a mask according to an experimental example of the present invention. 16 and 17 show (1) plane, (2) milling line, (3) side cross-section cut along the milling line, (4) side cross-sectional enlarged photograph of each sample, and FIG. 18 is a side cross-sectional enlarged photograph indicates. The mask pattern P was formed in a circular shape on a plane basis.

Table 1 below shows data obtained by measuring the mask thickness, the taper angle (ta), and the height of the left/right barriers of each sample. The heights of the left/right barriers correspond to t2' and t1' shown in FIG. 15(b) , respectively. 16 and 17 representatively show Samples 1 and 2, and FIG. 18 shows Samples 3-6.

Sample Mask thickness (㎛) Taper Angle Left/Right (°) Right chin (㎛) Left chin (㎛) One 15.53 42.7 / 45.4 3.65 3.67 2 14.61 45.7 / 45.1 3.33 3.20 3 15.02 47.9 / 50.3 3.97 4.02 4 13.82 44.5 / 46.3 3.54 2.76 5 13.94 46.9 / 45.4 3.90 2.84 6 11.46 43.0 / 41.4 2.12 1.88

16 to 18 , a mask pattern P having the same shape as in FIG. 15 can be confirmed, both sides of the first mask pattern P1 have a concave curvature, and both sides of the second mask pattern P2 have a convex curvature. Alternatively, a shape close to a straight line can be confirmed. Also, referring to Table 1, it is confirmed that the height of the barrier tends to decrease as the thickness of the mask decreases. It can be seen that the taper angle is lower than 55°, and the height of the barrier compared to the thickness of the mask is 23.6%, 22.8%, 26.7%, 25.6%, 27.9%, and 18.4%, respectively, which is less than 30% at the maximum.

Hereinafter, a process of attaching the mask 100 on the frame 200 using the manufactured mask support template 50 will be described.

19 is a schematic diagram illustrating a state in which the template 50 is loaded onto the frame 200 and the mask 100 corresponds to the cell region CR of the frame 200 according to an embodiment of the present invention. In FIG. 19 , one mask 100 is exemplified to correspond/attach to the cell region CR, but a plurality of masks 100 are simultaneously mapped to all cell regions CR to form the mask 100 into the frame 200 . ) may be attached to the In this case, a plurality of templates 50 supporting each of the plurality of masks 100 may be provided.

The template 50 may be transferred by the vacuum chuck 90 . The mask 100 may be transferred by adsorbing the opposite surface of the template 50 to which the mask 100 is attached with the vacuum chuck 90 . After the vacuum chuck 90 adsorbs and flips the template 50 , even in the process of transferring the template 50 onto the frame 200 , the adhesive state and alignment state of the mask 100 are not affected.

Next, referring to FIG. 19 , the mask 100 may correspond to one mask cell region CR of the frame 200 . By loading the template 50 on the frame 200 (or the mask cell sheet unit 220 ), the mask 100 may correspond to the mask cell region CR. While controlling the position of the template 50/vacuum chuck 90, it is possible to check whether the mask 100 corresponds to the mask cell region CR through a microscope. Since the template 50 compresses the mask 100 , the mask 100 and the frame 200 may be in close contact.

Meanwhile, the lower support 70 may be further disposed under the frame 200 . The lower support 70 may press the opposite surface of the mask cell region CR to which the mask 100 contacts. At the same time, since the lower support 70 and the template 50 press the edge and the frame 200 (or the mask cell sheet part 220 ) of the mask 100 in opposite directions, the mask 100 is The alignment state can be maintained without being disturbed.

Then, the mask 100 may be attached to the frame 200 by irradiating the laser L to the mask 100 by laser welding. A welding bead WB is generated in the welding part of the laser-welded mask, and the welding bead WB may have the same material as that of the mask 100/frame 200 and may be integrally connected.

20 is a schematic diagram illustrating a process of separating the mask 100 and the template 50 after attaching the mask 100 to the frame 200 according to an embodiment of the present invention.

Referring to FIG. 20 , after the mask 100 is attached to the frame 200 , the mask 100 and the template 50 may be debonded. Separation of the mask 100 and the template 50 may be performed through at least one of heat application (ET), chemical treatment (CM), ultrasonic application (US), and UV application (UV) to the temporary adhesive part 55 . have. Since the mask 100 remains attached to the frame 200 , only the template 50 can be lifted. For example, when heat of a temperature higher than 85° C. to 100° C. is applied (ET), the viscosity of the temporary adhesive part 55 is lowered, and the adhesive force between the mask 100 and the template 50 is weakened, so that the mask 100 ) and the template 50 may be separated. As another example, the mask 100 and the template 50 can be separated by dissolving or removing the temporary adhesive part 55 by immersing (CM) the temporary adhesive part 55 in a chemical substance such as IPA, acetone, or ethanol. have. As another example, when ultrasound is applied (US) or UV is applied (UV), the adhesive force between the mask 100 and the template 50 is weakened, so that the mask 100 and the template 50 may be separated.

21 is a schematic diagram illustrating a state in which the mask 100 is attached to the frame 200 and the barrier insulating part 23 is removed according to an embodiment of the present invention. 21 shows a state in which all the masks 100 are attached to the cell region CR of the frame 200 . After attaching the masks 100 one by one, the templates 50 may be separated, but after all the masks 100 are attached, all the templates 50 may be separated.

The template 50 is separated from the mask 100 by the vacuum chuck 90 , and the barrier insulating part 23 may remain on the upper surface of the mask 100 . In the case of the curable photoresist, the barrier insulating portion 23 is not easily removed by a wet process. Accordingly, in order to remove the barrier insulating portion 23 on the mask 100 , at least one of plasma PS and UV (UV) may be applied. After loading the frame-integrated masks 100 and 200 in a separate chamber (not shown), atmospheric pressure plasma or vacuum plasma (PS) or UV (UV) is applied to remove only the barrier insulating part 23. can

As described above, the present invention has the effect of more precisely controlling the size and position when finally forming the mask pattern P because the barrier can be thinly left while forming the first mask pattern P1 as deep as possible. . In addition, as a mask support template including the mask metal film 110 / barrier insulating portion 23 / temporary adhesive portion 55 / template 50 is used, an error due to etchant penetration / leakage occurs in the wet etching process This has the effect of preventing it from happening.

Although the present invention has been illustrated and described with reference to preferred embodiments as described above, it is not limited to the above-described embodiments and is not limited to the above-described embodiments, and various methods can be made by those of ordinary skill in the art to which the invention pertains without departing from the spirit of the present invention. Transformation and change are possible. Such modifications and variations are intended to fall within the scope of the present invention and the appended claims.

23: barrier insulation
25: insulation
50: Template
55: temporary adhesive
100: mask
110: mask metal film
200: frame
C: cell, mask cell
CR: mask cell area
M1. M2, M3: 1st, 2nd, 3rd insulation part
P: mask pattern
P1, P1-1, P1-2: first mask pattern
P2, P2-1, P2-2: second mask pattern
SN: Hall
WE1, WE2, WE3: wet etching

Claims (11)

delete delete delete delete delete delete A template for supporting a mask for forming an OLED pixel, comprising:
template;
a temporary adhesive formed on the template; and
A mask bonded on a template through a temporary adhesive and formed with a plurality of mask patterns
includes,
A barrier insulating part is further formed on the temporary adhesive part, and the mask is adhered to the upper surface of the template through the temporary adhesive part and the barrier insulating part;
The mask pattern may include an upper first mask pattern; and a lower second mask pattern,
The thickness of the first mask pattern is thicker than the thickness of the second mask pattern,
Both sides of the first mask pattern are formed to have a concave curvature,
The upper width of the first mask pattern is greater than the lower width of the second mask pattern, the lower width of the first mask pattern is smaller than the lower width of the second mask pattern,
The first mask pattern and the second mask pattern are formed by wet etching, and when the second mask pattern is wet-etched, the etchant is etched from the exposed portion of the barrier insulating part in the lateral direction so that the lower width of the second mask pattern is the upper part. A mask support template that is formed to be greater than a width. delete 8. The method of claim 7,
The mask support template, wherein both side surfaces of the second mask pattern are formed to have a convex curvature. A method of manufacturing a frame-integrated mask in which at least one mask and a frame supporting the mask are integrally formed, the method comprising:
(a) preparing a frame having at least one mask cell region;
(b) loading the mask support template of claim 7 onto the frame so that the mask corresponds to the mask cell region of the frame; and
(c) attaching the mask to the frame;
Including, a method of manufacturing a frame-integrated mask. A frame-integrated mask in which a plurality of masks and a frame supporting the masks are integrally formed,
frame is,
an edge frame unit including a hollow region;
a mask cell sheet portion having a plurality of mask cell regions and connected to the edge frame portion;
including,
Each mask on which a plurality of mask patterns are formed is connected to an upper portion of the mask cell sheet portion,
The connection of the mask cell sheet portion of the mask is performed by loading the mask support template of claim 7 on the frame and attaching the mask to the frame, the frame-integrated mask.

Images