CN113540385A

CN113540385A - Mask metal film, mask metal film supporting template, mask supporting template, and method for manufacturing same

Info

Publication number: CN113540385A
Application number: CN202110367006.2A
Authority: CN
Inventors: 李永浩; 韩进求; 李东真; 张泽龙
Original assignee: Wuluomao Materials Co ltd
Current assignee: Wuluomao Materials Co ltd
Priority date: 2020-04-22
Filing date: 2021-04-06
Publication date: 2021-10-22
Also published as: TWI770929B; TW202207503A

Abstract

The invention relates to a mask metal film, a mask metal film supporting template and a manufacturing method thereof. The mask metal film is used for manufacturing a mask for forming OLED pixels, at least comprises a central part of a metal film (sheet) manufactured by a rolling process, and at least one surface comprises a circular shape or an x-axis length: the ratio of the length of the y axis is 1: 1 to 3: 1, elliptical defect.

Description

Mask metal film, mask metal film supporting template, mask supporting template, and method for manufacturing same

Technical Field

The invention relates to a mask metal film, a mask metal film supporting template, a mask supporting template and a manufacturing method thereof. And more particularly, to a mask metal film, a mask metal film supporting template, a mask supporting template, and a method of manufacturing the same, which form a fine mask pattern on a mask, enable the mask to be stably supported and moved without deformation, and enable accurate alignment (align) between masks on a frame.

Background

As a technique for forming pixels in an OLED manufacturing process, an FMM (Fine Metal Mask) method is mainly used, which attaches a Metal Mask (Shadow Mask) in the form of a thin film to a substrate and deposits an organic substance on a desired position.

The existing mask manufacturing method is manufactured by the following method: a metal thin plate used as a mask is prepared, and patterning is performed after PR coating is performed on the metal thin plate or a mask having a pattern is manufactured by etching after PR coating for forming a pattern is performed. In the ultra-high definition OLED, the conventional QHD image quality is 500-600PPI (pixel per inch), the size of the pixel reaches about 30-50 μm, and the 4K UHD and 8K UHD high definition have higher resolution of 860PPI, 1600PPI and the like. Therefore, it is required to develop a technique capable of precisely adjusting the size of the mask pattern.

In addition, in the existing OLED manufacturing process, after the mask is manufactured in a bar shape, a plate shape, or the like, the mask is solder-fixed to the OLED pixel deposition frame and used. To fabricate a large area OLED, a plurality of masks may be fixed to an OLED pixel deposition frame, and each mask is stretched to be flattened during the fixing to the frame. Adjusting the tensile force to flatten the entire portion of the mask is a very difficult task. In the process of fixing a plurality of masks to one frame, there is still a problem that alignment between masks and between mask units is not good. In addition, in the process of fixing the mask to the frame by welding, the mask film has a problem that the mask is too thin and large in area, and therefore the mask is sagged or distorted by a load.

In this way, in consideration of the pixel size of the ultra-high-definition OLED, it is necessary to reduce the alignment error between the units to about several μm, and exceeding this error causes product defects, so the yield may be extremely low. Therefore, it is necessary to develop a technique capable of preventing deformation such as sagging or twisting of the mask and making alignment accurate, a technique of fixing the mask to the frame, and the like.

Disclosure of Invention

Technical problem

The present invention has been made to solve the above-described problems of the related art, and an object of the present invention is to provide a mask metal film, a mask metal film supporting template, a mask supporting template, and a method for manufacturing the same, which are capable of forming a fine mask pattern on a mask.

Another object of the present invention is to provide a method for manufacturing a frame-integrated mask, which can prevent deformation such as sagging and warping of the mask and can accurately align the mask.

Technical scheme

The above object of the present invention is achieved by a mask metal film supporting template for supporting and corresponding to a frame a mask metal film used in manufacturing a mask for OLED pixel formation, the template comprising: a template; a temporary bonding portion formed on the template; and a mask metal film bonded to the template by interposing a temporary bonding portion, the mask metal film including at least a central portion of the metal film manufactured by a rolling process, at least one surface including a circular shape or an x-axis length: the ratio of the length of the y axis is 1: 1 to 3: 1, elliptical defect.

The mask metal film may be in a state where no particles are present in the circular or elliptical defect.

The side face of the defect of the mask metal film may form an angle of 0 ° to 30 ° with the xy-plane.

The width of the defect of the mask metal film may be less than 30 μm (more than 0).

The x-axis may be parallel to the rolling direction.

The mask metal film may have a thickness of 5 to 20 μm by performing a surface defect removing process and a thickness reducing process on at least one side of the metal film manufactured through the rolling process.

Performing a surface defect removal process on 2.5% to 12.5% of the initial reference thickness of the mask metal film so that the shape of the defect, i.e., the x-axis length: the ratio of the y-axis length is represented by k: l is changed to m: n, where k and l are positive numbers, k is a number greater than l, and m and n are positive numbers, and k/l > m/n can be satisfied.

The surface defect removal process is performed by any one of Lapping, Polishing, and Buffing, and the thickness reduction process may be performed by wet etching.

The mask metal film includes a mask cell area as an area for forming a mask pattern and a dummy portion area around the mask cell area, and a thickness of a portion corresponding to the soldering portion in the dummy portion area may be at least greater than a thickness of the remaining area.

When the upper surface is 0% and the lower surface is 100% based on the thickness of the mask metal film produced by the rolling process, at least a part corresponding to a 10% to 90% thickness portion of the mask metal film is used in the center portion.

Further, the above object of the present invention is achieved by a method of manufacturing a mask supporting template for supporting an OLED pixel forming mask and corresponding it to a frame, comprising the steps of: (a) bonding the mask metal film manufactured through the rolling process to a template having a temporary bonding part formed on one surface thereof; (b) removing surface defects and reducing the thickness on the first side of the mask metal film; (c) the thickness is reduced by etching on the first face of the mask metal film.

The step (a) may include the steps of: (a1) forming an insulating portion on a second surface opposite to the first surface of the mask metal film; (a2) a mask metal film is bonded to an upper surface of a template, on one surface of which a temporary bonding portion is formed, with an insulating portion interposed therebetween.

May further comprise the steps of: (d) separating the mask metal film from the template; (e) bonding the first surface of the mask metal film to a second template having a temporary bonding portion formed on one surface thereof; (f) removing surface defects and reducing the thickness of the mask metal film on the reverse side, namely the second side, of the first side; (g) the thickness is reduced by etching at the second side of the mask metal film.

The thickness reduction of step (b) may be performed for 2.5% to 12.5% of the initial reference thickness of the mask metal film.

Step (b) may be performed by any one of Lapping, Polishing, and Buffing.

The thickness reduction of step (c) may be performed with a thickness reduction amount greater than that of step (b).

Step (c) may be performed by wet etching.

After step (c), the thickness of the mask metal film may be 5 μm to 20 μm.

The morphology of the defects present on the first face after step (b), i.e. the x-axis length: the ratio of the y-axis length is represented by k: l is changed to m: n, where k and l are positive numbers, k is a number greater than l, and m and n are positive numbers, and k/l > m/n is satisfied.

After step (b), particles included within the defect on the first face may be removed.

After the step (b), an insulating portion is formed on a remaining region except for the mask cell portion of the mask metal film or on the soldering portion region of the mask metal film, and the step (c) is performed on a region where the insulating portion is not formed.

Further, the above object of the present invention is achieved by a method of manufacturing a mask supporting stencil for supporting and corresponding to a frame an OLED pixel forming mask, comprising the steps of: (a) bonding a mask metal film manufactured through a rolling process to a template having a temporary bonding part formed on one surface thereof; (b) removing surface defects and reducing the thickness on the first side of the mask metal film; (c) reducing the thickness by etching on the first side of the mask metal film; and (d) manufacturing a mask by forming a mask pattern on the mask metal film.

Further, the above object of the present invention is achieved by a method of manufacturing a mask supporting stencil for supporting and corresponding to a frame an OLED pixel forming mask, comprising the steps of: (a) preparing a mask metal film manufactured through a rolling process; (b) removing surface defects and reducing the thickness on the first side of the mask metal film; (c) reducing the thickness by etching on the first side of the mask metal film; (d) manufacturing a mask by forming a mask pattern on the mask metal film; and (e) adhering the mask to the template having the temporary adhering portion formed on one surface thereof.

Further, the above object of the present invention is achieved by a mask metal film for manufacturing a mask for forming an OLED pixel, comprising at least a central portion of a metal film (sheet) manufactured through a rolling process, at least one surface including a metal film having a circular or x-axis length: the ratio of the length of the y axis is 1: 1 to 3: 1, elliptical defect.

Further, the above object of the present invention is achieved by a method for manufacturing a mask metal film, comprising the steps of: (a) preparing a mask metal film (sheet) manufactured through a rolling process; (b) removing surface defects and reducing the thickness on the first side of the mask metal film; and (c) reducing the thickness by etching on the first face of the mask metal film.

Further, the above object of the present invention is achieved by a method for manufacturing a mask metal film, the frame-integrated type mask being formed by at least one mask integrally with a frame for supporting the mask, wherein the method comprises the steps of: (a) loading the mask supporting template manufactured by the method onto a frame having at least one mask unit region so that the mask corresponds to the mask unit region of the frame; (b) the mask is attached to the frame.

Advantageous effects

According to the present invention as described above, a fine mask pattern can be formed on a mask.

Further, according to the present invention, there is an effect that it is possible to prevent deformation such as sagging or twisting of the mask and to accurately align it.

Drawings

Fig. 1 is a front view and a side sectional view of a frame-integrated mask according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a mask according to an embodiment of the invention.

Fig. 3 is a schematic diagram of a mask metal film and a schematic diagram of a surface defect of the mask metal film according to an embodiment of the invention.

Fig. 4 is a schematic view of a manufacturing process of a mask metal film according to an embodiment of the present invention.

Fig. 5 is a schematic view of a process of manufacturing a mask metal film on a mask supporting template according to an embodiment of the present invention.

Fig. 6 is a schematic view of a process of forming a mask by bonding a mask metal film on a template to manufacture a mask supporting template according to an embodiment of the present invention.

Fig. 7 is a schematic view of a state in which a template is loaded on a frame so that a mask corresponds to a unit region of the frame according to an embodiment of the present invention.

Fig. 8 is a schematic diagram of a process of separating a mask from a template after attaching the mask to a frame according to an embodiment of the present invention.

Fig. 9 is a schematic view of a state in which a mask is attached to a cell region of a frame according to an embodiment of the present invention.

Fig. 10 is surface photographs before and after a surface defect removing process of a mask metal film according to an experimental example of the present invention.

Fig. 11 is a surface optical microscope photograph of a defect sample of a mask metal film before and after a surface defect removal process according to an experimental example of the present invention.

Fig. 12 is a surface AFM (Atomic Force Microscope) photograph before and after a surface defect removing process is performed on a defect sample of a mask metal film according to an experimental example of the present invention.

Fig. 13 to 16 are optical microscope photographs at respective magnifications before and after a surface defect removal process is performed on a defect sample of a mask metal film according to an experimental example.

Reference numerals:

40. 45, and (2) 45: support substrates 41, 46: adhesive agent

50: template (template) 51: laser passing hole

55: temporary bonding portion 100: mask and method for manufacturing the same

110. 110', 110 ": mask film, mask metal film

111': first side 112' of mask metal film: second surface of mask metal film

113': first surface layer of mask metal film

114': masking the second surface layer of the metal film

115': center portion 116' of the mask metal film: upper layer part of mask metal film

117': lower layer portion 200 of mask metal film: frame structure

210: the edge frame portion 220: mask unit sheet part

221: edge sheet portion 223: first grid sheet part

225: second grid sheet portion 1000: OLED pixel deposition device

C: cell, mask cell CR: mask unit region

DM: dummy portion, mask dummy portion L: laser

P: mask pattern PS 1: surface defect removal process

PS 2: thickness reduction process WB: welding bead

WP: weld part

Detailed Description

The present invention is described in detail below with reference to the attached drawing figures, which are intended to illustrate examples of specific embodiments in which the invention may be practiced. These embodiments are described in detail to enable those skilled in the art to fully practice the invention. The various embodiments of the invention should be understood as distinct and not mutually exclusive. For example, the particular shapes, structures and characteristics described herein may enable one embodiment to be implemented within other embodiments without departing from the spirit and scope of the present invention. In addition, the location or arrangement of individual elements within each disclosed embodiment should be understood as being modified without departing from the spirit and scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims, along with the full scope of equivalents to which such claims are entitled. In the drawings, like numerals refer to the same or similar functions throughout the several views, and the length, area, thickness, etc. and forms thereof may be exaggerated for convenience.

Fig. 1 is a front view ((a) of fig. 1) and a side sectional view ((b) of fig. 1) of a frame-integrated mask according to an embodiment of the present invention.

In the following, the structure of the frame-integrated mask will be briefly described in the present specification, but the structure and the manufacturing process of the frame-integrated mask will be understood to be incorporated in the entirety of korean patent application No. 2018-0016186.

The conventional rod-shaped mask has a problem that alignment between mask units is not good even if tension applied to each axis of the rod-shaped mask is finely adjusted because a plurality of mask units are included in one mask. This is exemplified by the fact that the patterns of the cells are different from each other in distance or the patterns P are not uniform. The long bar-shaped mask is liable to sag or twist due to a load, and it is very difficult to observe the alignment state between the units through a microscope while adjusting the tensile force in order to make the units all in a flat state. The present invention can prevent the mask 100 integrated with the frame 200 from being deformed such as drooping or twisting and can be accurately aligned with the frame 200.

Referring to fig. 1, the frame integrated mask may include a plurality of masks 100 and a frame 200. In other words, the plurality of masks 100 are attached to the frame 200. For convenience of explanation, the mask 100 having a rectangular shape will be described as an example, but the mask 100 may have a bar-shaped mask shape having protrusions for sandwiching both sides before being attached to the frame 200, and the protrusions may be removed after being attached to the frame 200.

Each mask 100 has a plurality of mask patterns P formed thereon, and one mask 100 may have one cell C formed thereon. One mask unit C may correspond to one display of a smartphone or the like.

The mask 100 may be made of invar (invar), super invar (super invar), nickel (Ni), nickel-cobalt (Ni-Co), or the like. The mask 100 may use a sheet metal (sheet) generated by a rolling process or electroforming.

The frame 200 may be formed in a form of attaching a plurality of masks 100. The frame 200 is preferably formed of invar, super invar, nickel-cobalt, etc. having the same thermal expansion coefficient as the mask in consideration of thermal deformation. The frame 200 may include a generally square, box-shaped edge frame portion 210. The interior of the edge frame portion 210 may be hollow.

In addition, the frame 200 is provided with a plurality of mask unit regions CR, and may include a mask unit sheet portion 220 connected to the edge frame portion 210. The mask unit sheet portion 220 may be composed of an edge sheet portion 221, and first and second

grid sheet portions

223 and 225. The edge sheet portion 221, the first grid sheet portion 223, and the second grid sheet portion 225 are portions divided on the same sheet, and are formed integrally with each other.

The thickness of the edge frame part 210 may be greater than that of the mask unit sheet part 220, and may be formed in a thickness of several mm to several tens cm. The thickness of the mask die portion 220, although thinner than the thickness of the edge frame portion 210, is thicker than the mask 100, and may be about 0.1mm to 1mm thick. The width of the first and second

grid sheet portions

223, 225 may be about 1-5 mm.

In the planar sheet, a plurality of mask unit regions CR may be provided except for the regions occupied by the edge sheet portion 221, the first grid sheet portion 223, and the second grid sheet portion 225 (CR11-CR 56).

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

Fig. 2 is a schematic diagram of a mask 100 according to an embodiment of the invention.

The mask 100 may include a mask unit C formed with a plurality of mask patterns P and a dummy portion DM around the mask unit C. The mask 100 may be manufactured using a metal sheet produced by a rolling process, electroforming, or the like, and one cell C may be formed in the mask 100. The dummy portion DM corresponds to a portion of the mask film 110[ mask metal film 110] other than the cell C, and may include only the mask film 110, or include the mask film 110 formed with a predetermined dummy portion pattern similar to the morphology of the mask pattern P. The dummy portion DM corresponds to an edge of the mask 100 and a part or the whole of the dummy portion DM may be attached to the frame 200[ the mask die portion 220 ].

The width of the mask pattern P may be less than 40 μm and the thickness of the mask 100 may be about 5-20 μm. Since the frame 200 is provided with a plurality of mask cell regions CR (CR11-CR56), it is also possible to provide a plurality of masks 100, the masks 100 having mask cells C (C11-C56) corresponding to each mask cell region CR (CR11-CR 56). Further, a plurality of templates 50 for supporting a plurality of masks 100, which will be described later, respectively, may be provided.

Fig. 3 is a schematic view of a mask metal film (a) and surface defects of the mask metal film [ (b), (c) ] according to an embodiment of the present invention.

In order to manufacture the above-described mask 100 in fig. 2, a process of forming a mask pattern P is required to be performed on the mask metal film 110. The mask pattern P may be formed by etching (etching) or the like. In order to realize an OLED of high resolution above UHD, the width of the mask pattern P should be less than 40 μm, and the thickness of the mask metal film used should be thinner than 20 μm or less in consideration of the tapered shape, the inclined shape of the mask pattern P.

Since the mask pattern P needs to be formed finely, the shape and orientation of crystal grains (grains) in the mask metal film 110' should be taken into consideration when performing etching. The etching rate (etching rate) varies depending on the orientation of the crystal grains, and if uneven crystal grains are etched, it may be difficult to generate a mask pattern P having a desired width, and even an error of several μm may affect the high resolution.

Referring to fig. 3 (a), in a metal film (sheet) produced by rolling, the surface, i.e., the upper surface and the lower surface, of the metal film generally have a difference in the form, orientation, and the like of crystal grains from the central portion of the metal film. The portion 116 "(upper layer portion 116") from the upper surface 111 "of the mask metal film 110" to a predetermined thickness and the portion 117 "(lower layer portion 117") from the portion surface 112 "to a predetermined thickness are different in crystal grain characteristics from the portion corresponding to the central portion 115" except for the upper layer portion 116 "and the lower layer portion 118". The upper portion 116 "and the lower portion 117" have irregular shapes in which crystal grains are aligned long in the rolling direction by rolling. The grains in the central portion 115 "are substantially non-directional and have a spherical morphology. Therefore, in order to prevent etching errors due to different crystal grain morphologies, it is preferable to consider performing a thickness reduction process on the upper portion 116 "and the lower portion 117" of the mask metal film 110 "and manufacturing the mask 100 using the mask metal film 110 including the central portion 115". If only the central portion 115 ″ having irregular and uniform crystal grains is etched to form the mask pattern P, there is an advantage that the width of the mask pattern P can be finely controlled.

According to the embodiment of the present invention, when the upper surface is 0% and the lower surface is 100% based on the thickness of the mask metal film 110 ″, at least a part of 10% to 90% of the thickness portion of the central portion 115 ″. In other words, the thickness reduction by the surface defect removal process PS1 and the thickness reduction process PS2 described later can be performed in about 10% to 90% of the entire thickness of the mask metal film 110 ″, and the thickness reduction of each side can be performed in about 5% to 45% when the processes PS1 and PS2 are performed on both sides. However, without being limited thereto, if the central portion 115 "uses at least a part of 10% to 90% of the thickness portion based on the thickness of the mask metal film 110", the degree of thickness reduction in each of the processes PS1, PS2 may be changed.

Further, as shown in fig. 3 (a), when the thickness reduction process of the mask metal film 110 ″ is performed, defects (defects) existing on the surface may also be considered with emphasis.

Referring to fig. 3 (b), the surface of the mask metal film 110' has a scratch defect SD1 such as a rolling scratch, a dimple (dimple) and the like, and a particle defect SD2 such as an oxide of SiO2, Al2O3 and the like, which are foreign substances, generated by pressing the metal film during rolling. These defects SD1, SD2 still result in defects in center portion 115 "after the thickness reduction process of masking metal film 110'.

As shown in fig. 3(c), when the thickness reduction process is performed by the etching WE, there may occur a problem that the etching is performed according to the morphology of the scratch defect SD1 (SD1- > SD1' - > SD1 "). In addition, particle defect SD2 may cause a problem of masking the etching WE or changing the etching ratio and etching only the periphery of particle defect SD2 (SD2- > SD2'- > SD2 "- > SD 2'"). In other words, the surface morphology of scratch defect SD1 and particle defect SD2 may be transferred to central portion 115 ″ as it is.

Therefore, it is a feature of the present invention that after these surface defects SD1, SD2 are removed, the mask metal film 110 is manufactured by performing a thickness reduction process. Since the thickness reduction process is performed on the surface that is planarized by removing surface defects SD1, SD2, the surface still has the advantages of a homogenized, planarized state after the thickness reduction.

Referring to (a) of fig. 4, a mask metal film 110' manufactured through a rolling process may be prepared. Surface defects SD1, SD2 may be present on one surface 111 '(first surface) or both surfaces 111', 112 '(first surface, second surface) of the mask metal film 110'. The present invention can perform the surface defect removal and thickness reduction process only on one side 111', or can perform the surface defect removal and thickness reduction process on the other side 112' after performing the surface defect removal and thickness reduction process on one side 111 '. For convenience of explanation, the following description will discuss the case where surface defects SD1 and SD2 are removed simultaneously from both surfaces 111 'and 112' and the thickness is reduced simultaneously from both surfaces.

Next, the surfaces 111', 112' of the mask metal film 110' may be subjected to a surface defect removal process PS 1. Surface defect removal process PS1 is a process for removing scratch defect SD1 and particle defect SD2 described in FIG. 3.

The surface defect removal process PS1 can be performed by any one of Lapping (Lapping), Polishing (Polishing), and Buffing (Buffing) which can be used for fine surface treatment. The thickness of the mask metal film 110' may also be reduced by the surface defect removal process PS 1. However, it is preferable to perform the etching on 2.5% to 12.5% of the initial reference thickness of the mask metal film. As an example, the thickness of the mask metal film 110' having a thickness of about 40 μm can be reduced by about 1 to 5 μm by the surface defect removal process PS 1. This is because surface defects SD1, SD2 have a predetermined depth and the curvature of at least the depth becomes flatter by surface defect removal process PS 1. The flatter the surface, the more the problem of transfer due to surface morphology can be prevented when performing the etching process described in fig. 3 (c). In addition, the surface defect removal process PS1 has a slower thickness reduction rate than the later-described etching thickness reduction process PS2, and thus, when processing is performed for a relatively thin thickness, process efficiency is facilitated.

Then, referring to fig. 4 (b), after the surface defect removing process PS1, the surface layers 113', 114' may be reduced and removed from the surfaces 111', 112' by a predetermined thickness. After the surface of the mask metal film 110' a is subjected to the surface defect removing process PS1, defects are reduced and the surface becomes more flat. As described later with reference to fig. 11, the depth of scratch defect SD1 may be reduced, the planar shape may be changed from a laterally elongated shape to a nearly circular shape, and particle defect SD2 may be removed.

Then, referring to fig. 4 (c), a thickness reduction process PS2 is performed. The thickness reduction of the thickness reduction process PS2 may be greater than the thickness reduction of the surface defect removal process PS 1. In order to enable a rapid reduction of the thicker thickness, the thickness reduction process PS2 may be performed by etching, in particular by wet etching. Since the surface defects SD1, SD2 of the mask metal film 110' a are removed, the thickness reduction can be performed along a uniform surface.

The thickness reduction process PS2 may be performed for the portions 116', 117' corresponding to the predetermined thickness. The portions 116', 117' correspond to the upper portion 116 "lower portion 117" of the rolled invar alloy described in fig. 3 (a), and relatively irregular crystal grains are formed in the portions compared to the central portion 115 '. As an example, the mask metal film 110' with a thickness of about 40 μm can be reduced by about 15-34 μm.

Then, referring to fig. 4 (d), after the thickness reduction process PS2 is performed, the portions 116', 117' corresponding to the predetermined thickness may be reduced and removed. After the thickness reduction, the final thickness of the mask metal film 110 may be about 5 μm to 20 μm.

In addition, the surface defect removal process PS1 and the thickness reduction process PS2 may be performed only on the mask unit C portion of the mask metal film 110' (see fig. 2). That is, by performing the surface defect removing process PS1 and the thickness reducing process PS2 only for the mask cell C portion where the mask pattern P is to be formed, a fine mask pattern P can be formed in a subsequent process. In other words, in order to make the mask 100 described later adhere to the frame 200 by welding [ see fig. 7], the welding portion WP may be formed to have a thickness at least larger than that of the mask unit C. For this reason, the surface defect removing process PS1 and the thickness reducing process PS2 may be performed only for the portion other than the welding portion WP (or at least a portion of the dummy portion DM).

After the surface defect removing process PS1, an insulating portion (not shown) such as a photoresist is formed on the portion of the mask unit C, and the thickness of the mask unit C is reduced by a thickness reducing process PS2, so that a difference in thickness and a step difference can be formed with respect to the mask unit C portion, the welding portion WP [ or the dummy portion DM ]. Thus, the thickness of the other portion except the mask unit C portion or the welding portion WP portion may be about 5 to 20 μm, and the welding portion WP or the dummy portion DM portion may have a thicker thickness.

The mask metal film 110 of the present invention has a regular grain shape because it includes the center portion 115' of the rolled metal film, and has a uniform surface and no defect on the surface, so that it has an effect of performing a precision etching process in the process for forming the mask pattern P.

As an example, the surface defect removal process PS1 and the thickness reduction process PS2 of the mask metal film 110 may be performed on the

support substrates

40, 45. The support substrates 40 and 45 correspond to a template 50 described later in fig. 6, and may be replaced with the template 50. There are advantages in that the mask pattern P can be formed and the mask 100 can be manufactured immediately after the mask metal film 110 is formed on the template 50, and the frame-integrated mask can be manufactured immediately after the template 50 supporting the mask 100 is moved to the frame 200.

Referring to fig. 5 (a), the lower surface 112' (the second surface, i.e., the opposite surface of the first surface 111 ') of the mask metal film 110' may be bonded to the support substrate 40 by using the bonding part 41. The adhesive portion 41 may be made of the same material as the temporary adhesive portion 55 described later or may be made of any material that has a certain adhesive force and is separable after the application.

After the mask metal film 110 'is adhered to the support substrate 40, a surface defect removal process PS1 and a thickness reduction process PS2 may be performed on the upper face 111' (first face). After the surface defect removal process PS1, the surface layer 113 'of the mask metal film 110 ″ may be reduced and removed, and after the thickness reduction process PS2, the upper layer 116' may be reduced and removed.

The states of the support substrate 40, the bonding portion 41, and the mask metal film 110' b may be directly replaced by the step (b) of fig. 6 described later. At this time, the support substrate 45 may correspond to the template 50, and the adhesive portion 45 may correspond to a temporary adhesive portion 55 described later. Even if the surface defect is removed on one side of the mask metal film 110' but not on both sides and the thickness reduction process is performed, the defective portion can be prevented from being transferred based on etching when the mask pattern P is formed. This is because the etching process flow for forming the mask pattern P is performed along the direction of the first face where the surface defects are removed. The case where the processes are performed on both sides is further described by (b) to (d) of fig. 5.

Then, referring to fig. 5 (b), another support substrate 45 is prepared, and then the upper face (first face) of the mask metal film 110' b may be bonded to the support substrate 45 by using the bonding portion 46. The support substrate 45 and the adhesive part 45 may be the same as the support substrate 40 and the adhesive part 41. The support substrate 45 may correspond to a template 50 described later, and the adhesive portion 45 may correspond to a temporary adhesive portion 55 described later. In this case, steps (b) to (d) of fig. 5 may be replaced with step (b) of fig. 6.

Then, referring to fig. 5 (c), after the mask metal film 110' b is adhered to the support substrate 45, the support substrate 40 may be separated. Next, a surface defect removal process PS1 and a thickness reduction process PS2 are performed on the second surface 112 ″. After the surface defect removal process PS1, the surface layer 114 'of the mask metal film 110 ″ may be reduced and removed, and after the thickness reduction process PS2, the lower layer 117' may be reduced and removed.

Then, referring to fig. 5 (d), the fabrication of the mask metal film 110 may be ended. The mask metal film 110 includes a central portion 115', and the thickness of the mask metal film 110 may be about 5 μm to 20 μm.

In addition, in fig. 4 and 5, it is assumed that the mask metal film 110 is made by a rolling process and explained, and even in the case of a mask metal film manufactured by another process such as electroforming, characteristic differences may exist in the crystal grains of the surface portion and the central portion, and therefore the same processes PS1, PS2 may be adopted.

Fig. 6 is a schematic view of a process of forming a mask 100 by bonding a mask metal film 110 on a template 50 to manufacture a mask supporting template according to an embodiment of the present invention.

In fig. 6 (a), a template (template)50 may be provided. The stencil 50 is a medium having one surface to which the mask 100 is attached and moves the mask 100 in a state of supporting the mask 100. The center portion 50a may correspond to the mask cell C of the mask metal film 110, and the edge portion 50b may correspond to the dummy portion DM of the mask metal film 110. In order to be able to support the mask metal film 110 as a whole, the stencil 50 is a flat shape having an area greater than or equal to the mask metal film 110.

To facilitate visual observation during alignment and bonding of the mask 100 to the frame 200, the template 50 preferably uses a transparent material. In the case of a transparent material, the laser beam may be allowed to penetrate therethrough. As the transparent material, glass (glass), silica gel (silica), heat-resistant glass, quartz (quartz), alumina (Al) can be used₂O₃) Borosilicate glass (borosilicate glass), zirconia (zirconia), and the like. As an example, the template 50 may use borosilicate glass having excellent heat resistance, chemical durability, mechanical strength, transparency, and the like

33 of a material. In addition to this, the present invention is,

33 has a thermal expansion coefficient of about 3.3, and has a small difference from that of the invar alloy mask metal film 110, and has an advantage that the mask metal film 110 can be easily controlled.

In addition, in order not to generate an air gap (airgap) between the interface with the mask metal film 110 (or the mask 100), the side of the stencil 50 contacting the mask metal film 110 may be a mirror surface. In view of this, the surface roughness Ra of one side of the template 50 may be 100nm or less. In order to realize the template 50 having the surface roughness Ra of 100nm or less, a wafer (wafer) may be used as the template 50. The surface roughness Ra of the wafer is about 10nm, and a large number of products and surface treatment processes exist in the market, so that the wafer can be used as the template 50. The surface roughness Ra of the stencil 50 is nano-scale so that there is no or almost no air gap, and the solder ball WB is easily generated by laser welding, and thus may not affect the alignment error of the mask pattern P.

In order to allow the laser light L irradiated from the upper portion of the mask 50 to reach the welding portion WP (the region where welding is performed) of the mask 100, the mask 50 may be formed with a laser passing hole 51. The laser passage holes 51 can be formed in the mask 50 in a manner corresponding to the positions and the number of the welds WP. Since the plurality of welding portions WP are arranged at predetermined intervals on the edge or dummy portion DM portion of the mask 100, a plurality of laser passing holes 51 can be formed at predetermined intervals correspondingly. As an example, since the plurality of welding parts WP are arranged at predetermined intervals on both sides (left/right sides) of the dummy part DM portion of the mask 100, a plurality of laser passing holes 51 may be formed at predetermined intervals on both sides (left/right sides) of the template 50.

The positions and the number of the laser passage holes 51 do not necessarily correspond to the positions and the number of the welded portions WP. For example, the laser L may be irradiated only to a part of the laser passage holes 51 to perform welding. In addition, the laser passage holes 51 in the portions not corresponding to the welding portions WP may be used as alignment marks when aligning the mask 100 and the mask 50. If the material of the template 50 is transparent to the laser light L, the laser passage holes 51 may not be formed.

A temporary bonding portion 55 may be formed on one surface of the template 50. The temporary bonding part 55 may temporarily attach the mask 100 (or the mask metal film 110') to one surface of the stencil 50 and support it on the stencil 50 before the mask 100 is attached to the frame 200.

The temporary bonding portion 55 may use an adhesive or a bonding sheet that is releasable upon heating, an adhesive or a bonding sheet that is releasable upon irradiation of UV.

As an example, the temporary bonding portion 55 may use liquid wax (liquid wax). The liquid wax may be the same wax as that used in the polishing step of the semiconductor wafer or the like, and the type thereof is not particularly limited. As the resin component mainly used for controlling the adhesive force, impact resistance, and the like associated with the holding power, the liquid wax may include substances such as acrylic acid, vinyl acetate, nylon, and various polymers, and solvents. As an example, the temporary bonding portion 55 may use skyliquedabr-4016 including nitrile rubber (ABR) as a resin component and n-propanol as a solvent component. A liquid wax is formed on the temporary bonding portion 55 by a spin coating method.

The temporary bonding portion 55, which is liquid wax, has a decreased viscosity at a temperature higher than 85 deg.c to 100 deg.c and an increased viscosity at a temperature lower than 85 deg.c, and a portion is solidified into a solid, so that the mask metal film 110' can be fixedly bonded to the stencil 50.

Next, referring to fig. 6 (b), a mask metal film 110 may be adhered on the stencil 50. The liquid wax may be heated to 85 c or more and the mask metal film 110 is brought into contact with the stencil 50, after which the mask metal film 110 and the stencil 50 are passed between rollers to be adhered.

According to an embodiment, baking (baking) is performed on the template 50 at about 120 ℃ for 60 seconds, thereby vaporizing the solvent of the temporary bonding portion 55, and then a masking metal film lamination (plating) process may be performed immediately thereafter. The lamination is performed by loading the mask metal film 110 on the stencil 50 having the temporary bonding portion 55 formed on one side thereof and passing it between an upper roller (roll) of about 100 c and a lower roller of about 0 c. As a result, the mask metal film 110' can be brought into contact with the template 50 with the temporary bonding portion 55 interposed therebetween.

As another example, a thermal release tape (thermal release tape) may be used as the temporary adhesive portion 55. The thermal separation tape is a base film in which a PET film or the like is disposed in the middle, and both sides of the base film are disposed with a thermally separable adhesive layer (thermal release adhesive), and the outline of the adhesive layer may be disposed with a separation film/release film. Wherein the separation temperatures of the adhesive layers disposed on both sides of the base film may be different from each other.

According to an embodiment, in a state where the separation film/release film is removed, a lower surface of the thermal separation tape [ a lower second adhesive layer of the base film ] is adhered on the template 50, and an upper surface of the thermal separation tape [ an upper first adhesive layer of the base film ] may be adhered on the mask metal film 110'. Since the first adhesive layer and the second adhesive layer have different separation temperatures, when the template 50 is separated from the mask 100 in fig. 16, the mask 100 can be separated from the template 50 and the temporary bonding portion 55 by heating the first adhesive layer.

In addition, the masking metal film 110 may be used in which the processes PS1, PS2 of fig. 4 are performed on one side or both sides. Alternatively, (b) of fig. 6 may be replaced with a state after performing the processes PS1, PS2 on one side after adhering the mask metal film 110' to the support substrate 40 (corresponding to the template 50) as in step (a) of fig. 5. Further, (b) of fig. 6 may be replaced with a state after the processes PS1, PS2 are performed on one side after the mask metal film 110 'is bonded to the support substrate 40 (corresponding to the template) and the processes PS1, P2 are performed on the other side after the mask metal film 110' b is bonded to the support substrate 45 (corresponding to the second) as in (a) to (d) of fig. 5.

In addition, in fig. 4, the thickness reduction process PS2 of fig. 5 can be performed only on the mask unit C. After the surface defect removing process PS1, an insulating portion (not shown) such as a photoresist is formed only in a region corresponding to the welding portion WP of the mask metal film 110', or after an insulating portion (not shown) such as a photoresist is formed only in a region corresponding to the welding portion WP of the mask metal film 110' in a state where the mask metal film 110' is adhered to and supported by the mask 50, a process PS2 is performed with respect to the mask unit C portion to form the welding portion WP with a relatively large thickness and a step difference with the mask unit C portion, and the surface of the mask unit C portion where the mask pattern P is to be formed can be made defect-free.

The lower surface of the mask metal film 110 may be further provided with an insulating portion (not shown) such as a photoresist, or may be bonded to the temporary bonding portion 55 with the insulating portion interposed therebetween. In step (c) of fig. 6, an insulating portion is further formed in order to prevent etching liquid from penetrating into the interface between the mask metal film 110 and the temporary bonding portion 55, damaging the temporary bonding portion 55/the template 50, and generating an etching error of the mask pattern P. In order to have strong durability against the etching liquid, the insulating part may include at least one of a curable negative photoresist, an epoxy-containing negative photoresist. As an example, it is preferable that the black matrix photoresist (black matrix) is cured together in the baking of the temporary adhesion part 55, the baking of the insulation part 25 (refer to fig. 6 (c)), and the like by using the SU-8 photoresist based on epoxy resin.

Then, referring to fig. 6 (c), a patterned insulating portion 25 may be formed on the mask metal film 110. The insulating portion 25 may be formed of a photoresist material by a printing method or the like.

Next, the mask metal film 110 may be etched. Dry etching, wet etching, or the like may be used without limitation, and as a result of the etching, portions of the mask metal film 110 exposed by the empty spaces 26 between the insulating parts 25 may be etched away. The etched portions of the mask metal film 110 form mask patterns P, so that the mask 100 formed with a plurality of mask patterns P can be manufactured.

At this time, since the mask metal film 110 is in a state where the surface defects are removed, the mask metal film can be etched in a desired pattern form in the etching process. A fine mask pattern P may be formed, and thus has an effect of enabling the fabrication of the mask 100 that may be used in a high resolution OLED pixel process.

Then, referring to fig. 6 (d), the manufacture of the template 50 supporting the mask 100 may be ended by removing the insulating part 25.

In addition, instead of the steps (b) and (c) of fig. 6, the mask 100 having the plurality of mask patterns P formed on the mask metal film 110 is directly bonded to the template 50 with the temporary bonding portion 55 interposed therebetween, so that the template 50 for supporting the mask 100d can be manufactured.

Fig. 7 is a schematic view of a state where the template 50 is loaded on 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. The manner of corresponding/attaching one mask 100 to the cell region CR is illustrated in fig. 7, and a plurality of masks 100 may be simultaneously corresponding to all the cell regions CR and attaching the masks 100 to the frame 200. At this time, there may be a plurality of templates 50 respectively supporting a plurality of masks 100.

The template 50 may be removed by a vacuum chuck 90. The mask 100 may be transferred by sucking the surface of the template 50 opposite to the surface thereof to which the mask is adhered by a vacuum chuck 90. The bonding state and alignment state of the mask 100 are not affected in the process of transferring the template 50 to the frame 200 after the vacuum chuck 90 sucks and turns over the template 50.

Referring next to fig. 7, the mask 100 may be corresponded to one mask cell region CR of the frame 200. The mask 100 may be corresponded to the mask unit region CR by loading the template 50 to the frame 200 or the mask unit sheet part 220. Whether the mask 100 corresponds to the mask unit region CR or not can be observed through a microscope while controlling the position of the template 50/vacuum chuck 90. Since the template 50 presses the mask 100, the mask 100 can be closely attached to the frame 200.

In addition, the lower support 70 may be further disposed at the lower portion of the frame 200. The lower supporter 70 may press the opposite surface of the mask unit region CR in contact with the mask 100. At the same time, since the lower support 70 and the mask 50 press the edge of the mask 100 and the frame 200 (or the mask die part 220) in opposite directions to each other, the alignment state of the mask 100 can be maintained without being disturbed.

Next, the mask 100 is irradiated with laser light L and the mask 100 is attached to the frame 200 based on the laser welding. A bead WB is generated on a welding portion WP portion of the mask by laser welding, and the bead WB may have the same material as the mask 100/frame 200 and be integrally connected thereto.

Fig. 8 is a schematic view of a process of separating a mask from a template after attaching the mask to a frame according to an embodiment of the present invention.

Referring to fig. 8, after the mask 100 is attached to the frame 200, the mask 100 may be separated (bonding) from the template 50. The separation of the mask 100 from the template 50 may be performed by at least any one of heating ET, chemical treatment CM, application of ultrasonic waves US, and application of ultraviolet rays UV to the temporary bonding portion 55. Since the mask 100 is maintained in the state of being attached to the frame 200, only the stencil 50 can be lifted. As an example, if heat ET of a temperature higher than 85 ℃ -100 ℃ is applied, the viscosity of the temporary bonding portion 55 is lowered, the bonding force of the mask 100 and the stencil 50 is weakened, and thus the mask 100 and the stencil 50 can be separated. As another example, the mask 100 may be separated from the template 50 by immersing the temporary adhesion part 55 with CM in a chemical such as IPA, acetone, ethanol, or the like, in such a manner that the temporary adhesion part 55 is dissolved, removed, or the like. As another example, the mask 100 and the stencil 50 may be separated by weakening the adhesive force of the mask 100 and the stencil 50 by applying the ultrasonic wave US or applying the ultraviolet ray UV.

Fig. 9 is a schematic view of a state in which the mask 100 is attached to the frame 200 according to an embodiment of the present invention. A state in which all the masks 100 are attached to the cell regions CR of the frame 200 is illustrated in fig. 14. Although the templates 50 may be separated after the masks 100 are attached one by one, all the templates 50 may be separated after all the masks 100 are attached.

The template 50 is separated from the mask 100 by the vacuum chuck 90, and the first insulating portion 23 remains on the mask 100. If the first insulating portion 23 is a curable photoresist, it is not easily removed by a wet etching process. Therefore, at least any one of the plasma PS and the ultraviolet light UV may be applied in order to remove the first insulating portion 23 on the mask 100. After the frame-integrated

masks

100 and 200 are loaded in another chamber (not shown), only the first insulating layer 23 may be removed by applying atmospheric pressure plasma, vacuum plasma PS, or ultraviolet light UV.

Fig. 9 is a schematic view of a state in which the mask 100 is attached to the frame 200 according to an embodiment of the present invention.

Referring to fig. 9, one mask 100 may be adhered to one cell region CR of the frame 200. Since the mask unit sheet portions 220 of the frame 200 have a thin thickness, if the mask 100 is adhered to the mask unit sheet portions 220 in a state where a tensile force is applied, the tensile force remaining in the mask 100 will act on the mask unit sheet portions 220 and the mask unit regions CR, thereby deforming them. Therefore, the mask 100 should be adhered to the mask unit sheet part 220 in a state where no tensile force is applied to the mask 100. The present invention can complete the process of corresponding the mask 100 to the mask cell region CR of the frame 200 without applying any tensile force to the mask 100 only by attaching the mask 100 on the template 50 and loading the template 50 on the frame 200.

Since it is only necessary to correspond to one cell C of the mask 100 and confirm the alignment state, the present invention can significantly reduce the manufacturing time compared to the conventional method in which a plurality of cells C (C1-C6) are simultaneously corresponding and all the alignment states need to be confirmed.

In addition, in (b) of fig. 6, as described above, when the mask metal film 110 is adhered to the stencil 50 through the lamination process, a temperature of about 100 c is applied to the mask metal film 110. Thereby, the mask metal film 110 is bonded to the stencil 50 in a state where a partial tensile force is applied. Then, if the mask 100 is attached to the frame 200 and the template 50 is separated from the mask 100, the mask 100 may be contracted by a certain amount.

If the template 50 is separated from the masks 100 after each mask 100 is attached to the corresponding mask cell region CR, since the plurality of masks 100 apply tensions contracting in opposite directions, the tensions are offset from each other, and thus no deformation occurs in the mask cell sheet portions 220. For example, in the first grid sheet portion 223 between the mask 100 attached to the CR11 cell region and the mask 100 attached to the CR12 cell region, the tension acting in the right direction of the mask 100 attached to the CR11 cell region and the tension acting in the left direction of the mask 100 attached to the CR12 cell region may cancel each other out. Accordingly, the deformation of the frame 200 (or the mask die section 220) due to the tension is minimized, thereby having an advantage of minimizing an alignment error of the mask 100 (or the mask pattern P).

Next, the case of removing surface defects SD1 and SD2 by the surface defect removal process PS1 detailed in fig. 4 will be understood by an experimental example.

Fig. 10 is surface photographs before and after a surface defect removing process of a mask metal film according to an experimental example of the present invention. Fig. 10 (a) and (c) and (b) and (d) show before and after the process in the same region.

According to an experimental example, a rolled invar metal film having a thickness of 40 μm was subjected to the surface defect removal process PS1 by Buffing (buffering) at a thickness of 2 μm.

As can be seen from (a) and (b) of fig. 10, the surface of the mask metal film has a scratch defect SD1 such as a rolling scratch generated when the metal film is pushed in the rolling process. Considering that the rolling direction is the x-axis direction, it was confirmed that (a) long and thin scratch defect SD1 of 100 μm or more and (b) long and thin scratch defect SD1 and scratch defect SD1 of 10 μm or more formed particle defect SD2 of an oxide or a foreign substance such as SiO2 or Al2O 3.

Referring to fig. 10 (c), it can be confirmed that the scratch defect SD1 has been removed. Although it is an elongated scratch defect SD1 of 100 μm or more, since the depth of the defect is less than 2 μm, the defect can be removed.

Referring to fig. 10 (d), it was confirmed that elongated scratch defect SD1 was in a quasi-circular shape and particle defect SD2 was removed. That is, the size of scratch defect SD1 is reduced and particle defect SD2 has been removed. However, according to the size of particle defect SD2 disposed on scratch defect SD1, it was confirmed that the morphology of elongated scratch defect SD1 became very thin and circular-like. The depth is sufficiently shallow and in a circular diffusion form, so even if etching for forming the mask pattern P is performed, uniform flatness can be maintained due to a small curvature form of the defect. Finally, even if the defect morphology is transferred during the etching process, no error or negligence is generated.

The following table shows the number and size of defects before and after the surface defect removal process PS 1. Defects were confirmed in an area of 100mmX100mm for 9 specimens.

[ Table 1]

Test specimen	Number of defects before the process	Number of defects after the process
			1	1	0
2	3	3
			3	14	8
4	15	4
			5	17	10
6	7	7
			7	8	8
8	1	0
			9	1	0
Total of	67	39

[ Table 2]

Percentile defect size	Defect size before technology (mum)	Defect size after Process (μm)
			MAX(100％)	373.3	20.9
75％	25.6	11.1
			MEDIAN(50％)	17.7	10.6
25％	12.8	7.1
			MIN(0％)	5.7	4.5
Average	56.7	10.3

Referring to table 1, it can be seen that all of the 9 samples exhibited defect removal/reduction after the process. All defects in samples 1, 8, and 9 were removed. Samples 2 to 7 showed that the number of defects was constant or decreased, and these defects coexisted with scratch defect SD1 and particle defect SD2, and it was confirmed that the morphology of scratch defect SD1 changed from a slender shape to a circular shape.

As can be seen from table 2, the size of the defect becomes smaller. In other words, it was confirmed that the elongated scratch defect SD1 in samples 2 to 7 had a circular shape while decreasing in size.

The elongated scratch defect SD1 is a defect having a transverse length larger than a vertical length in a plane. Namely, x-axis length: the length of the y axis is k: l (k, l is a positive number), k may be greater than l. This defect becomes circular after process PS1, x-axis length: the length of the y axis is m: n (m, n are positive numbers), and k/l > m/n. That is, at least the lateral length is reduced, the vertical length becomes large, resulting in a small defect.

Thus, the mask metal film 110 of the present invention may have surface round or quasi-round defects. Alternatively, the elongated scratch defect SD1 also remains as a substantially elliptical defect as the frame is rounded.

Defect SD1 may become a more planar morphology as the curvature decreases. As defect SD1 becomes circular, the curvature of the edge of defect SD1 may become smaller, the depth of the defect becomes smaller, and thus may become flat. At this time, the defect that becomes flat is observed, and the angle formed by the side face of the defect and the xy plane (or the surface of the mask metal film 110) may be 0 ° to 30 °. If the angle is 0 °, it means that no curvature in the depth direction is kept in conformity with the surface of the mask metal film 110. When the processes of the masking metal film 110 of PS1, PS2 are completed and the mask pattern P is formed, the side surfaces of the mask pattern P may be formed in a reverse taper shape forming a taper angle of about 45 ° to 70 ° with the xy plane (or, the surface of the masking metal film 110). Therefore, in consideration of the angle of the mask pattern P, if the side surface angle of the defect is close to the angle of the mask pattern P, there may occur a problem that the surface defect of the mask metal film 110 remains in a form similar to the mask pattern P before the mask pattern P is formed, and thus the side surface angle of the defect should be sufficiently smaller than the angle of the mask pattern P.

Fig. 11 is a surface optical microscope photograph of a defect sample for a mask metal film before and after a surface defect removal process according to an experimental example of the present invention. Fig. 11 is a photograph of 4 recognizable defects (#1 to #4) extracted in one sample.

Referring to fig. 11 (a), it can be seen that #1 to #4 are both elongated defects. In particular, the defect indicated by the dotted circle is a defect in which scratch defect SD1 further includes particle defect SD 2.

Referring to fig. 11 (b), after PS1, most of the defects of #1 to #4 except for the defects indicated by the dotted circles are removed. In #1, #3, #4, it was confirmed that elongated scratch defect SD1 including particle defect SD2 became circular. In addition, it was confirmed that the depth of the defect was also reduced by reducing the depth of the color after the process of PS 1.

Fig. 12 is a surface afm (atomic Force microscope) photograph of a defect sample for a mask metal film before and after a surface defect removal process according to an experimental example of the present invention.

It can be easily found with reference to fig. 12 that the surface of the mask metal film becomes more homogeneous after the process PS 1. Fig. 12(a) shows the shading of the horizontal stripes, and each part of the surface shows a large height difference, whereas fig. 12(b) shows a gradual shading except for the dotted circle part, and the height of the surface part is relatively flat. Further, it was confirmed that the depth of the defect becomes smaller by the color depth of the dotted circle portion after the process PS1 becoming lighter.

Fig. 13 to 16 are optical microscope photographs at respective magnifications before and after a surface defect removal process for a defect sample of a mask metal film according to an experimental example. Fig. 13, 14, 15 and 16 are photographs observed at 50, 200, 500 and 1000 magnifications for defects #1, #2, #3 and #4, respectively. The zigzag thick lines around the dotted circumference are arbitrarily marked on the surface for the purpose of facilitating the observation of defects.

Referring to fig. 13, 15 and 16, it can be confirmed that the defects #1, #3 and #4 are elongated defects. In particular, the defect indicated by the dotted circle is a defect in which scratch defect SD1 further includes particle defect SD 2. Further, it was confirmed that elongated scratch defect SD1 including particle defect SD2 became circular. By making the color depth lighter after the process PS1, it was confirmed that the depth of the defect also became smaller.

Referring to fig. 14, the defect #2 is also a long defect. In particular, the defect indicated by the dotted circle was confirmed to be a defect in which scratch defect SD1 further included particle defect SD 2. Only, defect #2 is shown as the degree of removal after process PS 1. This can be understood as the case where the depth of particle defect SD2 in process PS1 is shallow or the initial state appears non-circular due to the detachment of particle defect SD2 and the defect is removed.

The following table shows the defect sizes after the surface defect removal process PS1, determined by fig. 13 to 16.

[ Table 3]

Referring to Table 3, it can be seen that particle defect SD2 was removed after PS1 in all 4 defects. Further, it was confirmed that the x-axis length decreased at a rate of increase or decrease of-45.5%, -25.2%, -4.8%, -14.8%, and the y-axis length increased at a rate of increase or decrease of 45.1%, 13.2%, 36.2%, 15.0%. From this, it was found that the form of the defect changed from a slender form to a circular form.

In addition, the x-axis length of 4 defects after the process PS 1: the ratio of the y-axis length corresponds to about 1.41: 1. 1.30: 1. 2.49: 1. 2.47: 1. more than 3 before process PS 1: defects SD1, SD20 of 1 become rounded after process PS1, or become x-axis long: the ratio of the length of the y axis is 1: 1 to 3: 1, near oval shape. It was confirmed that the x-axis length or the y-axis length of the defect was less than 30 μm.

As described above, the present invention has an effect of maintaining a uniform surface state without defects on the surface by performing a surface defect reduction process of a mask metal film. Next, in order to maintain a homogeneous surface state after the thickness reduction process is performed, a fine mask pattern P may be formed in an etching process for forming the mask pattern P.

As described above, the present invention has been illustrated and described with reference to the preferred embodiments, but the present invention is not limited to the above-described embodiments, and various changes and modifications can be made by those skilled in the art without departing from the spirit of the present invention. Such variations and modifications are intended to be within the scope of the present invention and the appended claims.

Claims

1. A mask metal film supporting stencil for supporting and corresponding to a frame a mask metal film used in manufacturing a mask for OLED pixel formation, wherein the mask metal film supporting stencil comprises:

a template;

a temporary bonding portion formed on the template; and

a mask metal film bonded to the stencil by interposing a temporary bonding portion,

the mask metal film includes at least a central portion of the metal film manufactured through the rolling process,

at least one surface comprises a circular or x-axis length: the ratio of the length of the y axis is 1: 1 to 3: 1, elliptical defect.

2. The masking metal film supporting stencil of claim 1, wherein,

the mask metal film is in a state where no particles are present in the circular or elliptical defect.

3. The masking metal film supporting stencil of claim 1, wherein,

the side face of the defect of the mask metal film forms an angle of 0 ° to 30 ° with the xy plane.

4. The masking metal film supporting stencil of claim 1, wherein,

the width of the defect of the mask metal film is more than 0 and less than 30 μm.

5. The masking metal film supporting stencil of claim 1, wherein,

the x-axis is parallel to the rolling direction.

6. The masking metal film supporting stencil of claim 1, wherein,

the mask metal film has a thickness of 5 to 20 μm by performing a surface defect removing process and a thickness reducing process on at least one side of the metal film manufactured through the rolling process.

7. The masking metal film supporting stencil of claim 6, wherein,

performing a surface defect removal process on 2.5% to 12.5% of the initial reference thickness of the mask metal film so that the shape of the defect, i.e., the x-axis length: the ratio of the y-axis length is represented by k: l is changed to m: n is the sum of the numbers of the n,

wherein k and l are positive numbers, k is a number greater than l, and m and n are positive numbers, and k/l > m/n is satisfied.

8. The masking metal film supporting stencil of claim 6, wherein,

the surface defect removal process is performed by any one of grinding, polishing, and lapping, and the thickness reduction process is performed by wet etching.

9. The masking metal film supporting stencil of claim 1, wherein,

the mask metal film includes a mask cell region as a region for forming a mask pattern and a dummy portion region around the mask cell region,

the thickness of the portion corresponding to the welding portion in the dummy portion area is at least larger than that of the remaining area.

10. The masking metal film supporting stencil of claim 1, wherein,

11. A method of manufacturing a mask metal film supporting template for supporting and corresponding to a mask metal film for OLED pixel formation to a frame, wherein the method comprises the steps of:

(a) bonding the mask metal film manufactured through the rolling process to a template having a temporary bonding part formed on one surface thereof;

(b) removing surface defects and reducing the thickness on the first side of the mask metal film;

(c) the thickness is reduced by etching on the first face of the mask metal film.

12. The method of manufacturing a masking metal film supporting template as claimed in claim 11, wherein the step (a) comprises the steps of:

(a1) forming an insulating portion on a second surface opposite to the first surface of the mask metal film;

(a2) a mask metal film is bonded to an upper surface of a template, on one surface of which a temporary bonding portion is formed, with an insulating portion interposed therebetween.

13. The method of manufacturing a masking metal film supporting template as claimed in claim 11, further comprising the steps of:

(d) separating the mask metal film from the template;

(e) bonding the first surface of the mask metal film to a second template having a temporary bonding portion formed on one surface thereof;

(f) removing surface defects and reducing the thickness of the mask metal film on the reverse side, namely the second side, of the first side;

(g) the thickness is reduced by etching at the second side of the mask metal film.

14. The method of manufacturing a masking metal film supporting template as claimed in claim 11,

the thickness reduction of step (b) is performed for 2.5% to 12.5% of the initial reference thickness of the mask metal film.

15. The method of manufacturing a masking metal film supporting template as claimed in claim 14,

the step (b) is performed by any one of grinding, polishing and lapping.

16. The method of manufacturing a masking metal film supporting template as claimed in claim 14,

the thickness reduction of step (c) is performed with a thickness reduction amount greater than that of step (b).

17. The method of manufacturing a masking metal film supporting template as claimed in claim 16,

step (c) is performed by wet etching.

18. The method of manufacturing a masking metal film supporting template as claimed in claim 16,

after step (c), the mask metal film has a thickness of 5 μm to 20 μm.

19. The method of manufacturing a masking metal film supporting template as claimed in claim 11,

the morphology of the defects present on the first face after step (b), i.e. the x-axis length: the ratio of the y-axis length is represented by k: l is changed to m: n is the sum of the numbers of the n,

20. The method of manufacturing a masking metal film supporting template as claimed in claim 11,

removing particles included in the defect on the first face after step (b).

21. The method of manufacturing a masking metal film supporting template as claimed in claim 11,

22. A method of manufacturing a mask supporting stencil for supporting and corresponding to a frame an OLED pixel forming mask, the method comprising the steps of:

(c) reducing the thickness by etching on the first side of the mask metal film; and

(d) the mask is manufactured by forming a mask pattern on the mask metal film.

23. A method of manufacturing a mask supporting stencil for supporting and corresponding to a frame an OLED pixel forming mask, the method comprising the steps of:

(a) preparing a mask metal film manufactured through a rolling process;

(c) reducing the thickness by etching on the first side of the mask metal film;

(d) manufacturing a mask by forming a mask pattern on the mask metal film; and

(e) a mask is bonded to a template having a temporary bonding portion formed on one surface thereof.

24. A mask metal film for manufacturing a mask for forming OLED pixels, wherein,

including at least a central portion of the metal film produced by the rolling process,

25. A method for manufacturing a mask metal film, comprising the steps of:

(a) preparing a mask metal film manufactured through a rolling process;

(b) removing surface defects and reducing the thickness on the first side of the mask metal film; and

26. A method for manufacturing a frame-integrated mask integrally formed of at least one mask and a frame for supporting the mask, wherein the method comprises the steps of:

(a) loading a mask supporting template manufactured by the method of claim 22 or 23 onto a frame having at least one mask unit region so that a mask corresponds to the mask unit region of the frame;

(b) the mask is attached to the frame.