阅读说明：本技术 掩模的制造方法、掩模支撑模板的制造方法及框架一体型掩模的制造方法 (Method for manufacturing mask, method for manufacturing mask-supporting template, and method for manufacturing frame-integrated mask ) 是由 李炳一 金奉辰 金辉寿 于 2021-05-26 设计创作，主要内容包括：本发明涉及掩模的制造方法、掩模支撑模板的制造方法及框架一体型掩模的制造方法。本发明涉及的掩模的制造方法包括：(a)在掩模金属膜的一面上形成图案化的第一绝缘部的步骤；(b)在掩模金属膜的一面利用湿蚀刻以预定深度形成第一掩模图案的步骤；(c)至少在位于第一绝缘部的垂直下部的第一掩模图案内形成第二绝缘部的步骤；(d)在掩模金属膜的一面利用湿蚀刻形成从第一掩模图案贯通掩模金属膜的另一面的第二掩模图案的步骤；在步骤(a)中,在第一绝缘部图案之间进一步形成宽度小于第一绝缘部宽度的辅助绝缘部。(The present invention relates to a method for manufacturing a mask, a method for manufacturing a mask supporting template, and a method for manufacturing a frame-integrated mask. The method for manufacturing a mask according to the present invention includes: (a) a step of forming a patterned first insulating portion on one surface of the mask metal film; (b) a step of forming a first mask pattern at a predetermined depth on one surface of the mask metal film by wet etching; (c) a step of forming a second insulating portion at least in the first mask pattern located vertically below the first insulating portion; (d) forming a second mask pattern on one surface of the mask metal film by wet etching, the second mask pattern penetrating the other surface of the mask metal film from the first mask pattern; in the step (a), auxiliary insulating portions having a width smaller than that of the first insulating portions are further formed between the first insulating patterns.)

1. A method of manufacturing a mask, comprising:

(a) a step of forming a patterned first insulating portion on one surface of the mask metal film;

(b) a step of forming a first mask pattern at a predetermined depth on one surface of the mask metal film by wet etching;

(c) a step of forming a second insulating portion at least in the first mask pattern located vertically below the first insulating portion;

(d) forming a second mask pattern on one surface of the mask metal film by wet etching, the second mask pattern penetrating the other surface of the mask metal film from the first mask pattern;

in the step (a), auxiliary insulating portions having a width smaller than that of the first insulating portions are further formed between the first insulating patterns.

2. The method of manufacturing a mask according to claim 1, wherein in the step (b), the mask metal film exposed between the first insulating portion and the auxiliary insulating portion is wet-etched.

3. The method of manufacturing a mask according to claim 1, wherein when the interval between the patterns of the first insulating portion is 26 μm to 34 μm and the width of the auxiliary insulating portion is 12 μm to 16 μm, the thickness of the mask metal film corresponding to the vertical region between the patterns of the first insulating portion after the step (b) is at least less than 4 μm and more than 0.

4. The method of manufacturing a mask according to claim 1, wherein the step (c) comprises:

(c1) filling a second insulating portion at least in the first mask pattern;

(c2) volatilizing at least a part of the second insulating portion by baking;

(c3) and exposing the upper portion of the first insulating portion, and leaving only the second insulating portion vertically below the first insulating portion.

5. The method of manufacturing a mask of claim 1, wherein after the step (d), the first mask pattern has a thickness greater than that of the second mask pattern, an upper width greater than that of a lower width of the second mask pattern, and the lower width smaller than that of the second mask pattern.

6. The method of manufacturing a mask according to claim 5, wherein both side surfaces of the first mask pattern are formed to have a concave curvature, and both side surfaces of the second mask pattern are formed to have a convex curvature.

7. A method of manufacturing a mask support stencil, comprising:

(a) a step of bonding a mask metal film to the upper surface of the template;

(b) a step of forming a mask pattern on the mask metal film and manufacturing a mask;

the step (b) includes:

(b1) a step of forming a patterned first insulating portion on one surface of the mask metal film;

(b2) a step of forming a first mask pattern at a predetermined depth on one surface of the mask metal film by wet etching;

(b3) a step of forming a second insulating portion at least in the first mask pattern located vertically below the first insulating portion;

(b4) forming a second mask pattern on one surface of the mask metal film by wet etching, the second mask pattern penetrating the other surface of the mask metal film from the first mask pattern;

in the step (b1), auxiliary insulation portions having a width smaller than the width of the first insulation portions are further formed between the first insulation patterns.

8. The method of manufacturing a mask supporting template according to claim 7, wherein in the step (a), the mask metal film is adhered to the upper face of the template by interposing the spacer insulating section and the temporary adhering section.

9. The method of manufacturing a mask support template according to claim 7, wherein the spacer insulator comprises at least one of a cured negative photoresist, a negative photoresist containing an epoxy resin.

10. A method of manufacturing a frame-integrated mask integrally formed of at least one mask and a frame for supporting the mask, the method comprising:

(a) a step of bonding a mask metal film to the upper surface of the template;

(b) a step of forming a mask pattern on the mask metal film and manufacturing a mask;

(c) a step of loading the template onto a frame having at least one mask unit region so that the mask corresponds to the mask unit region of the frame; and

(d) a step of attaching the mask to the frame,

the step (b) includes:

(b1) a step of forming a patterned first insulating portion on one surface of the mask metal film;

(b2) a step of forming a first mask pattern at a predetermined depth on one surface of the mask metal film by wet etching;

(b3) a step of forming a second insulating portion at least in the first mask pattern located vertically below the first insulating portion;

(b4) forming a second mask pattern on one surface of the mask metal film by wet etching, the second mask pattern penetrating the other surface of the mask metal film from the first mask pattern;

in the step (b1), auxiliary insulation portions having a width smaller than the width of the first insulation portions are further formed between the first insulation patterns.

11. A method of manufacturing a frame-integrated mask integrally formed of at least one mask and a frame for supporting the mask, the method comprising:

(a) a step of loading the template manufactured by the manufacturing method of claim 7 on a frame having at least one mask unit region so that the mask corresponds to the mask unit region of the frame; and

(b) a step of attaching the mask to the frame.

Technical Field

The present invention relates to a method for manufacturing a mask, a method for manufacturing a mask supporting template, and a method for manufacturing a frame-integrated mask. More particularly, the present invention relates to a method for manufacturing a mask, a method for manufacturing a mask supporting template, and a method for manufacturing a frame-integrated mask, which can accurately control the size and position of a mask pattern.

Background

As a technique for forming pixels in an OLED (organic light emitting diode) 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 conventional mask manufacturing method prepares a metal thin plate used as a mask, performs PR coating on the metal thin plate and then patterning or performs PR coating to have a pattern and then manufactures the mask having the pattern by etching. However, in order to prevent the Shadow Effect (Shadow Effect), it is difficult to obliquely Taper the mask pattern (Taper), and an additional process needs to be performed, thereby causing an increase in process time and cost, and a decrease in productivity.

In the ultra-high quality OLED, the conventional QHD quality is 500-600PPI (pixel per inch), the pixel size reaches about 30-50 μm, and the 4KUHD and 8KUHD high quality has a resolution higher than that of-860 PPI and-1600 PPI. Therefore, it is urgently required to develop a technique capable of accurately 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. 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. Further, 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 quality OLED, it is necessary to reduce the alignment error between the respective 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

Accordingly, the present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a method for manufacturing a mask, a method for manufacturing a mask supporting template, and a method for manufacturing a frame integrated mask, which are capable of accurately controlling a mask pattern size.

Technical scheme

The above object of the present invention can be achieved by a method for manufacturing a mask, comprising: (a) a step of forming a patterned first insulating portion on one surface of the mask metal film; (b) a step of forming a first mask pattern at a predetermined depth on one surface of the mask metal film by wet etching; (c) a step of forming a second insulating portion at least in the first mask pattern located vertically below the first insulating portion; (d) forming a second mask pattern on one surface of the mask metal film by wet etching, the second mask pattern penetrating the other surface of the mask metal film from the first mask pattern; in the step (a), auxiliary insulating portions having a width smaller than that of the first insulating portions are further formed between the first insulating patterns.

In the step (b), the mask metal film exposed between the first insulating portion and the auxiliary insulating portion may be wet-etched.

When the interval between the patterns of the first insulating portions is 26 to 34 μm and the width of the auxiliary insulating portions is 12 to 16 μm, the thickness of the mask metal film corresponding to the vertical region between the patterns of the first insulating portions after the step (b) is at least less than 4 μm and more than 0.

Step (c) may comprise: (c1) filling a second insulating portion at least in the first mask pattern; (c2) volatilizing at least a portion of the second insulating portion by baking; (c3) and exposing the upper portion of the first insulating portion, and leaving only the second insulating portion vertically below the first insulating portion.

After the step (d), a thickness of the first mask pattern is greater than a thickness of the second mask pattern, an upper width of the first mask pattern is greater than a lower width of the second mask pattern, and the lower width of the first mask pattern is less than the lower width of the second mask pattern.

Both side surfaces of the first mask pattern may be formed to have a concave curvature, and both side surfaces of the second mask pattern may be formed to have a convex curvature.

Further, the above object of the present invention can be achieved by a method for manufacturing a mask supporting reticle, comprising: (a) a step of bonding a mask metal film to the upper surface of the template; (b) a step of forming a mask pattern on the mask metal film and manufacturing a mask; the step (b) includes: (b1) a step of forming a patterned first insulating portion on one surface of the mask metal film; (b2) a step of forming a first mask pattern at a predetermined depth on one side of the mask metal film by wet etching; (b3) a step of forming a second insulating portion at least in the first mask pattern located vertically below the first insulating portion; (b4) forming a second mask pattern on one surface of the mask metal film by wet etching, the second mask pattern penetrating from the first mask pattern to the other surface of the mask metal film; in the step (b1), auxiliary insulation portions having a width smaller than that of the first insulation portions are further formed between the first insulation portion patterns.

In the step (a), the mask metal film may be adhered to the upper face of the template by interposing the spacer insulating section and the temporary bonding section.

The spacer insulator may include at least one of a cured negative photoresist, a negative photoresist containing an epoxy resin.

Further, the above object of the present invention can be achieved by a method of manufacturing a frame-integrated mask integrally formed of at least one mask and a frame for supporting the mask, the method including: (a) a step of bonding a mask metal film to the upper surface of the template; (b) a step of forming a mask metal film and manufacturing a mask; (c) a step of loading the template onto a frame having at least one mask unit region so that the mask corresponds to the mask unit region of the frame; and (d) a step of attaching a mask to the frame, the step (b) including: (b1) a step of forming a patterned first insulating portion on one surface of the mask metal film; (b2) a step of forming a first mask pattern at a predetermined depth on one surface of the mask metal film by wet etching; (b3) a step of forming a second insulating portion at least in the first mask pattern located vertically below the first insulating portion; (b4) forming a second mask pattern on one surface of the mask metal film by wet etching, the second mask pattern penetrating the other surface of the mask metal film from the first mask pattern; in the step (b1), auxiliary insulation portions having a width smaller than the width of the first insulation portions are further formed between the first insulation patterns.

A method of manufacturing a frame-integrated mask integrally formed of at least one mask and a frame for supporting the mask, the method may include:

(a) a step of loading the template manufactured by the manufacturing method of claim 7 on a frame having at least one mask unit region so that the mask corresponds to the mask unit region of the frame; and (b) a step of attaching the mask to the frame.

Advantageous effects

According to the structure, the invention can accurately control the size and position of the mask pattern.

Drawings

Fig. 1 is a schematic view of a conventional process of attaching a mask to a frame.

Fig. 2 is a front view and a side sectional view of a frame-integrated mask according to an embodiment of the present invention.

FIG. 3 is a schematic diagram of a mask according to an embodiment of the invention.

Fig. 4 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. 5 is a schematic view of an etching degree of a mask according to a conventional mask manufacturing process and a comparative example.

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

Fig. 8 is a schematic view of the etching degree of the mask metal film according to an embodiment of the present invention.

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

Fig. 10 is a schematic view of an etching pattern of a mask metal film according to a comparative example and an embodiment of the present invention.

Fig. 11 is a schematic view of etching forms of the mask metal film in the comparative example and according to an embodiment of the present invention.

Fig. 12 is an SEM photograph for showing etching forms of the mask metal film according to the comparative example and the embodiment of the present invention.

Fig. 13 is a graph for showing the residual thickness of the mask metal film, the Step height, according to the comparative example and the embodiment of the present invention.

Fig. 14 is a graph for illustrating the residual thickness of the mask metal film, the height of the threshold, the first insulation portion pattern interval, and the auxiliary insulation portion pattern interval according to an embodiment of the present invention.

Fig. 15 is a schematic view for showing a process of manufacturing a mask subsequent to fig. 11.

Fig. 16 is a schematic view for showing a mask according to an embodiment of the present invention.

Fig. 17 is a schematic view of a state in which a template is loaded on a frame so that a mask corresponds to a cell region of the frame according to an embodiment of the present invention.

Fig. 18 is a schematic view of a process of separating the mask and the template after attaching the mask to the frame according to an embodiment of the present invention.

Fig. 19 is a schematic view of a state in which a mask is attached to a cell region of a frame and an insulating portion is removed, according to an embodiment of the present invention.

Reference numerals:

3: separator insulation

25: insulating part

50: form panel

55: temporary bonding part

100: mask and method for manufacturing the same

110: masking metal film

200: frame structure

C: cell and mask cell

CR: mask unit region

M1, M2, M3: first, second and third insulating parts

M4: auxiliary insulating part

P: mask pattern

P1, P1-1, P1-2: first mask pattern

P2, P2-1, P2-2: second mask pattern

SN: hole(s)

WE1, WE2, WE 3: wet etching

Detailed Description

The following detailed description of the invention refers to the accompanying drawings that illustrate specific embodiments in which the invention may be practiced. These embodiments are described in detail below in order to enable those skilled in the art to practice the invention. These embodiments are described in sufficient detail to enable those skilled in the art to 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 and all equivalents thereto. 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.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings in order to enable those skilled in the art to easily practice the invention.

Fig. 1 is a schematic view of a conventional process of attaching a mask 10 to a frame 20.

The conventional mask 10 is a stripe Type (Stick-Type) or a Plate Type (Plate-Type), and the stripe Type mask 10 of fig. 1 may be used by solder-fixing both sides of a stripe to an OLED pixel deposition frame. The mask 10 has a plurality of display cells C in its Body (Body, or mask film 11). One cell C corresponds to one display of the smartphone or the like. The cell C has a pixel pattern P formed therein so as to correspond to each pixel of the display.

Referring to fig. 1 (a), a tensile force F1 to F2 is applied along the longitudinal direction of the strip mask 10, and the strip mask 10 is mounted on the frame 20 having a box shape in an expanded state. The size of the frame 20 may be sufficient to allow the cells C1-C6 of one bar type mask 10 to be located in a blank area inside the frame, or may be sufficient to allow the cells C1-C6 of a plurality of bar type masks 10 to be located in a blank area inside the frame.

Referring to fig. 1 (b), the tensile forces F1 to F2 applied to the respective sides of the bar type mask 10 are finely adjusted while performing alignment, and then the bar type mask 10 and the frame 20 are connected to each other by welding a portion of the side of the W bar type mask 10. Fig. 1 (c) shows a side cross section of the bar type mask 10 and the frame connected to each other.

Although the tensile forces F1 to F2 applied to the sides of the strip type mask 10 are finely adjusted, a problem of poor alignment of the mask cells C1 to C3 with respect to each other still occurs. For example, the distances between the patterns P of the cells C1-C6 are different from each other or the patterns P are skewed. Since the stripe type mask 10 has a large area including the plurality of cells C1-C6 and has a very thin thickness of several tens of μm, it is easily sagged or distorted by a load. In addition, it is very difficult to confirm the alignment state of the cells C1 to C6 in real time by a microscope while adjusting the tensile forces F1 to F2 to flatten all the cells C1 to C6. However, in order to prevent the mask pattern P having a size of several μm to several tens μm from adversely affecting the pixel process of the ultra high quality OLED, the alignment error is preferably not greater than 3 μm. The alignment error between such adjacent cells is referred to as Pixel Position Accuracy (PPA).

Further, it is very difficult to precisely align the plurality of bar masks 10 and the plurality of cells C to C6 of the bar mask 10 while connecting the bar masks 10 to one frame 20, and it is important to increase the process time for alignment, which reduces the production efficiency.

In addition, after the bar type mask 10 is coupled and fixed to the frame 20, tensile forces F1 to F2 applied to the bar type mask 10 act reversely to the frame 20 as a tensile force. The tension causes a slight deformation of the frame 20 and a problem of distortion of the alignment state among the plurality of cells C1-C6 occurs.

In view of this, the present invention provides a frame 200 and a frame-integrated mask, which can form an integrated structure of a mask 100 and a frame 200. The mask 100 integrated with the frame 200 may not only prevent deformation such as sagging or twisting, but also be accurately aligned with the frame 200.

Fig. 2 is a front view ((a) of fig. 2) and a side sectional view ((b) of fig. 2) of a frame-integrated mask according to an embodiment of the present invention.

The present specification will describe the arrangement of the frame-integrated mask, but the structure and the manufacturing process of the frame-integrated mask may be understood to include the entire contents of korean patent application No. 2018-0016186.

Referring to fig. 2, 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, respectively. 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 clamping on 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 is formed with a plurality of mask patterns P, and one mask 100 may be formed with one cell C. 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 an edge frame portion 210 that is generally square, box-shaped. The interior of the edge frame portion 210 may be hollow in shape.

In addition, the frame 200 has a plurality of mask unit regions CR, and may include a mask unit piece part 220 connected to the edge frame part 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 integrated 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 cm. The thickness of the mask die section 220, although thinner than the thickness of the edge frame section 210, is thicker than the mask 100, and may be about 0.1mm to 1 mm. 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 (CR11 to CR56) may be provided in addition to the regions occupied by the edge sheet portion 221 and the first and second grid sheet portions 223, 225.

The mask 200 has a plurality of mask cell regions CR, and the masks 100 can 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). Thus, the mask 100 and the frame 200 may form an integrated structure.

Fig. 3 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 may include the mask film 110 formed with a predetermined dummy portion pattern having a similar form to 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 on the frame 200 (the mask die section 220).

The width of the mask pattern P may be less than 40 μm and the thickness of the mask 100 may be 5-20 μm. Since the frame 200 has a plurality of mask unit regions CR (CR11 to CR56), it may have a plurality of masks 100 including mask units C (C11 to C56) corresponding to the mask unit regions CR (CR11 to CR 56). Further, a plurality of reticles 50 for supporting a plurality of masks 100, which will be described later, are provided.

Fig. 4 is a schematic view of a process of forming a mask 100 by adhering a mask metal film 110 on a template 50 to manufacture a mask supporting template according to an embodiment of the present invention.

Referring to fig. 4 (a), a template (template)50 may be provided. The stencil 50 is a medium having a mask 100 attached to one surface thereof 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 has a flat plate shape having an area larger than or equal to the mask metal film 110.

The template 50 may be made of wafer, glass (glass), silicon dioxide (silica), pyrex (quartz), alumina (Al)₂O₃) Borosilicate glass (borosilicate glass), zirconia (zirconia), and the like. As an example, borosilicate glass, which is excellent in heat resistance, chemical resistance, mechanical strength, transparency, etc., can be used as the template 5033, respectively.In addition to this, the present invention is,33 has a thermal expansion coefficient of about 3.3, which is not much different from that of the invar mask metal film 110, and has an advantage of facilitating control of the mask metal film 110.

In order to allow the laser light L irradiated from the upper portion of the mask 50 to reach a welding portion WP (a 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 may be formed at predetermined intervals correspondingly thereto. As an example, since a 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 also 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 not corresponding to the welding portions WP may be used as alignment marks when aligning the mask 100 and the mask 50. The laser passing hole 51 may not be formed if the material of the template 50 is transparent to the laser light L.

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 side 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 by heat and an adhesive or a bonding sheet that is releasable by 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 and solvents such as acrylic acid, vinyl acetate, nylon, and various polymers. As an example, Acrylonitrile-butadiene rubber (ABR) may be used as the resin component of the temporary bonding portion 55, and SKYLIQUIDABR-4016 containing n-propanol may be used as the solvent component. The liquid wax may be 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. 4 (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, so that the masking metal film lamination (plating) process may be performed immediately after the solvent of the temporary bonding portion 55 is vaporized. 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 still another example, the temporary bonding portion 55 may use a thermal release tape (thermal release tape). The thermal release tape may be in a form in which a Core Film (Core Film) such as a PET Film is disposed in the middle, thermal release adhesive layers (thermal release adhesive) are disposed on both sides of the Core Film, and a release Film (releasing Film) is disposed to the outer periphery of the adhesive layers. Here, the adhesive layers disposed on both sides of the core film may have mutually different peelable temperatures.

According to an embodiment, in a state where the release film/release film is removed, a lower face of the thermal release tape (a lower second adhesive layer of the core film) is adhered to the film 50, and an upper face of the thermal release tape (an upper second adhesive layer of the core film) may be adhered to the mask metal film 110'. Since the first adhesive layer and the second adhesive layer have different peeling temperatures from each other, when the template 50 is detached from the mask 100 in fig. 18 described later, the mask 100 can be detached from the template 50 and the temporary bonding portion 55 as peeling heat is applied to the first adhesive layer.

In addition, the mask metal film 110 may use a mask metal film having one or both surfaces subjected to a surface defect removal process and a thickness reduction process. The thickness of the mask metal film 110 may be about 5 μm to 20 μm. It is also possible to perform the surface defect removal process and the thickness reduction process after the mask metal film 110 is adhered to the template 50. In addition, the thickness reduction process may be performed only for a portion of the mask unit C. After the surface defect removing process such as CMP, 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, 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 adhesively supported on the mask 50, an etching process for reducing the thickness of the mask unit C portion is performed to form the welding portion WP to be thick and to have a step difference with the mask unit C, and the surface of the mask unit C portion for forming the mask pattern P can be formed to be in a defect-free state.

Then, referring to fig. 4 (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 using a printing method or the like.

Next, etching of the mask metal film 110 may be performed. A method such as dry etching or wet etching may be used, but is not particularly limited, and as a result of etching, the mask metal film 110 exposed at the empty positions 26 between the insulating portions 25 is partially etched. The etched portion of the mask metal film 110 constitutes a mask pattern P, so that the mask 100 formed with a plurality of mask patterns P can be manufactured.

Then, referring to fig. 4(d), the fabrication of the template 50 supporting the mask 100 may be completed by removing the insulating part 25.

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

Fig. 5 is a schematic view showing an etching process (d) of a mask according to conventional mask manufacturing processes [ (a) to (c) ] and a comparative example.

Referring to fig. 5, the conventional mask manufacturing process only performs wet etching (wet etching).

First, as shown in fig. 5(a), a patterned photoresist M may be formed on a planarizing film 110' (sheet). Then, as shown in fig. 5 (b), wet etching WE may be performed through the space between the patterned photoresist M. After wet etching WE is performed, a part of the space of the film 110 'is penetrated, so that a mask pattern P' may be formed. Then, if the photoresist M is cleaned, the fabrication of the film 110' formed with the mask pattern P ', i.e., the mask 100', may be completed.

As shown in fig. 5 (c), the conventional mask 100 'has a problem that the size of the mask pattern P' is not necessarily the same. Since wet etching WE proceeds isotropically, the etched form is approximately in the shape of a circular arc. Further, since it is difficult to make the etching rate uniform in each portion during wet etching WE, the widths R1', R1 ", R1 '" of the through pattern after penetrating the film 110' are different from each other. In particular, in the pattern in which the undercuts UC (undercut) frequently occur, not only the lower width R1 "of the mask pattern P ' is formed to be wider, but also the upper width R2" is formed to be wider, and the lower widths R1', R1' "and the upper widths R2', R2 '" in the pattern in which the undercuts UC are less frequently occur are relatively formed to be narrower.

As a result, the conventional mask 100 'has a problem that the sizes of the respective mask patterns P' are not uniform. For ultra-high quality OLEDs, the QHD quality is currently 500-600PPI, the pixel size reaches about 30-50 μm, and the 4KUHD and 8KUHD high quality images have higher resolution ratios of-860 PPI and-1600 PPI, so the product defects may be caused by the small size difference.

Referring to fig. 5(d), since the wet etching WE proceeds isotropically, the etched form is approximately in the shape of a circular arc. In addition, in the wet etching, the etching speed of each portion is hardly exactly the same, and if the mask metal film 110 is penetrated by only 1 wet etching to form a mask pattern, the deviation thereof is larger. For example, although the wet etching rates of the mask pattern 111 and the mask pattern 112 are different, the difference in the top width (undercut) is not large. However, the difference between 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 is much larger than the difference in the upper width. This is a result of wet etching proceeding isotropically. In other words, the width determining the pixel size is the lower width PD1, PD2 of the mask patterns 111, 112, not the upper width, and thus, it is conceivable to adopt another wet etching method other than the 1-time wet etching to control the lower width PD1, PD 2.

Therefore, according to an aspect of the present invention, the accuracy of the mask pattern during the wet etching process may be improved by the wet etching a plurality of times.

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

Referring to fig. 6 (a), first, a mask metal film 110 as a metal sheet may be provided. The mask metal film 110 may be formed by a rolling process, electroforming, or the like, and the material of the mask metal film 110 may be invar (invar), super invar (super invar), nickel (Ni), nickel-cobalt (Ni-Co), or the like.

Then, a patterned 2 nd-1 st insulating portion M1 may be formed on one side (upper surface) of the mask metal film 110. The 2 nd-1 st insulating part M1 may be formed of a photoresist material by a printing method or the like. The insulating portions M1, M2, and M3 in fig. 6 to 7 are different from the spacer insulating portion 23 in the insulating portion 25 described later as insulating portions for forming the mask pattern P.

The first insulating portion M1 may be a black matrix photoresist (black matrix photoresist) or a photoresist material on which a metal plating film is formed. The material of the first insulating portion M1 may be a photoresist material different from that of the second insulating portion M2 or the third insulating portion M3, which will be described later, and is preferably an epoxy-based photoresist material. The black matrix photoresist may be a material including a black matrix resin (black matrix) for forming a black matrix of the display panel. The black matrix photoresist may have a superior light blocking effect than general photoresists. In addition, the photoresist having the metal plating film formed thereon has a good light shielding effect of shielding light irradiated from the upper portion by the metal plating film. The first insulating portion M1 may be a positive type photoresist material.

Then, referring to fig. 6 (b), a first mask pattern P1' of a predetermined depth may be formed on one side (upper surface) of the mask metal film 110 by wet etching WE 1. Although the first mask pattern P1' is formed in a substantially circular arc shape without penetrating the mask metal film 110, the first mask pattern (corresponding to the main etching pattern P1-2) is characterized to include the hole SN in the present invention explained with reference to fig. 11. For convenience of explanation, the hole portion is excluded in the explanation of fig. 6. That is, the depth value of the first mask pattern P1' excluding the hole SN may be smaller than the thickness of the mask metal film 110.

The wet etching WE1 has isotropic etching characteristics, and thus the width R2 of the first mask pattern P1 may have a width wider than the inter-pattern spacing R3 of the first insulating portion M1, unlike the inter-pattern spacing R3 of the first insulating portion M1. In other words, since the undercut UC (undercut) is formed at both lower sides of the first insulation portion M1, the width R2 of the first mask pattern P1' may be more than the width of the undercut UC formed than the interval R3 between the patterns of the first insulation portion M1.

Next, referring to fig. 6 (c), a second insulating portion M2 may be formed on one surface (upper surface) of the mask metal film 110. The second insulating portion M2 may be formed of a photoresist material by a printing method or the like. The second insulating portion M2 is preferably made of a positive photoresist material because it needs to remain in a space where an undercut UC is formed, which will be described later.

Since the second insulating portion M2 is formed on one face (upper face) of the mask metal film 110, a part is formed on the first insulating portion M1 and the other part is filled into the inside of the first mask pattern P1.

The second insulating portion M2 may use a photoresist diluted (dilution) in a solvent. If a high-concentration photoresist solution is formed on the mask metal film 110 and the first insulation portion M1, the high-concentration photoresist solution reacts with the photoresist of the first insulation portion M1, and thus there is a possibility that a portion of the first insulation portion M1 may be dissolved. Therefore, in order not to affect the first insulating portion M1, the second insulating portion M2 may use a photoresist whose concentration is decreased by dilution in a solvent.

Then, referring to fig. 7 (d), a portion of the second insulating portion M2 may be removed. As an example, a portion of the second insulating portion M2 may be removed in a volatile form by baking (baking). The solvent of the second insulating portion M2 is volatilized by the baking process, and only the photoresist component remains. Accordingly, the second insulating part M2' leaves a thin portion, such as a coated film, at the exposed portion of the first mask pattern P1 and the surface of the first insulating part M1. The thickness of the remaining second insulating portion M2' is preferably less than about several μ M so as not to affect the pattern width R3 of the first insulating portion M1 or the pattern width R2 of the first mask pattern P1.

Then, referring to fig. 7 (e), exposure L may be performed on one surface (upper surface) of the mask metal film 110. When the exposure L is performed on the upper portion of the first insulating portion M1, the first insulating portion M1 may function as an exposure mask. Since the first insulating portion M1 is a black matrix photoresist (black matrix photoresist) or a photoresist material on which a metal plating film is formed, the light shielding effect is excellent. Therefore, the second insulating portion M2 "[ refer to (f) of fig. 7 ] located vertically below the first insulating portion M1 is not exposed to light L, and the other second insulating portions M2' are exposed to light L.

Then, referring to (f) of fig. 7, if development is performed after exposure L, portions of the second insulating portion M2 ″ that are not exposed L are left, and the other second insulating portions M2' are removed. Since the second insulating portion M2' is a positive type photoresist, the portion exposed to light L is removed. The space reserved in the second insulating portion M2 ″ can correspond to a space in which undercuts UC [ refer to step (b) of fig. 6 ] are formed in the lower portions of both sides of the first insulating portion M1.

Then, referring to fig. 7 (g), wet etching WE2 may be performed on the first mask pattern P1 of the mask metal film 110. The wet etching liquid may permeate spaces between the patterns of the first insulating portion M1 and spaces of the first mask pattern P1, thereby performing wet etching WE 2. The second mask pattern P2 may be formed through the mask metal film 110. That is, the first mask pattern P1 is formed to penetrate the other surface of the mask metal film 110 from the lower end thereof.

At this time, the second insulating portion M2 ″ is left on the first mask pattern P1. The remaining second insulating portion M2 ″ may function as a mask for wet etching. That is, the second insulating portion M2 ″ masks (masking) the etching liquid and prevents the etching liquid from etching in the side surface direction of the first mask pattern P1, but etching in the lower surface direction of the first mask pattern P1.

Since the second insulation portion M2 "is disposed in the undercut UC space of the vertically lower portion of the first insulation portion M1, the pattern width of the second insulation portion M2" substantially corresponds to the pattern width R3 of the first insulation portion M1. Thus, the second mask pattern P2 corresponds to wet etching WE2 performed on the space R3 between the patterns of the first insulating portion M1. Accordingly, the width R1 of the second mask pattern P2 may be less 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 less than 35 μm. If the thickness of the second mask pattern P2 is excessively thick, it is difficult to control the width R1 of the second mask pattern P2, and the uniformity of the width R1 is degraded, and the shape of the mask pattern P as a whole may not be tapered/reverse tapered, so the thickness of the second mask pattern P2 is preferably smaller than that of the first mask pattern P1. The thickness of the second mask pattern P2 is preferably close to 0, and when 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 more preferably 0.5 to 2.0 μm.

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

Then, referring to (h) of fig. 7, the manufacture of the mask 100 may be completed by removing the first and second insulating portions M1 and M2 ″. The first mask patterns P1, P2 include inclined planes, and the height of the second mask pattern P2 is very low, so if the shapes of the first mask pattern P1 and the second mask pattern P2 are added together, the whole assumes a tapered shape or an inverted tapered shape.

In addition, between the steps (b) and (c) of fig. 6, the steps (b2) and (b3) may be further performed.

Referring to (b2) of fig. 6, a third insulation part M3 may be formed in the first mask pattern P1'. A third insulating portion M3 may be formed on at least a portion of the first mask pattern P1' exposed between the first insulating portions M1. For example, the third insulating portion M3 having a width R3 may be formed in an interval of patterns of an adjacent pair of first insulating portions M1, i.e., on the first mask pattern P1'.

For convenience of exposure, a negative type (negative type) photoresist material is preferably used for the third insulating portion M3. When the first mask pattern P1' is filled with a negative photoresist and the upper portion is exposed, the first insulating portion M1 functions as an exposure mask with respect to the third insulating portion M3, and it is possible to leave only the third insulating portion M3 exposed between the patterns of the first insulating portion M1. At this time, as illustrated in (c) of fig. 6, a third edge portion M3 having a width R3 may be formed on the first mask pattern P1'.

Then, referring to fig. 6 (b3), wet etching WE2 may be further performed on the first mask pattern P1'. Since the first mask pattern P1 'is partially in a state where the third insulating portion M3 is formed, the first mask pattern P1' is not further etched downward but is etched in a lateral direction. Accordingly, the width of the first mask pattern P1 'may be greater than R2(P1' - > P1).

Specific reasons for performing the steps (b2) and (b3) of fig. 6 are as follows.

If the steps (b2) and (b3) of fig. 6 are omitted and the first mask pattern P2 is formed after the first mask pattern P1' is formed, it may result in that it is difficult to reduce the taper angle of the mask pattern P ' (P1', P2). Based on the feature of the isotropic etching process of the first mask pattern P1', it is difficult for the side surface to have a small angle (an angle formed by the horizontal plane and the side of the mask pattern), and since the angle exceeds 60 ° or is nearly perpendicular, there is a case where the angle exceeds 70 ° even though the wet etching is performed twice. As a whole, the Shadow Effect (Shadow Effect) can be prevented only when the side of the mask pattern P forms an angle of about 30 ° to 70 ° with the horizontal plane, and if the angle is exceeded, the Shadow Effect is still generated, thereby causing difficulty in uniformly forming the OLED pixel.

In addition, in order to form the surface of the mask pattern P uniformly without roughness, the wet etching process needs to be performed in a short time. However, if the wet etching process is performed in a short time, the first mask pattern P1' is hardly formed at a small side angle. Finally, if the wet etching process is performed for a long time in order to form the side angle of the first mask pattern P1' into a small angle, there occurs a problem in that the surface of the mask pattern is rough and the morphology is not uniform.

Therefore, 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 as wet etching WE3(P1'- > P1) is further performed toward the side surface direction of the first mask pattern P1', there is an effect that the angle (a1- > a2) formed by the side surface of the first mask pattern P1 and the horizontal plane can be reduced. Since the wet etching is performed in two times to form the first mask pattern P1, each etching process does not need to be continued for a long time, and the surface morphology of the mask pattern P can be uniformly formed.

After wet etching WE3 is further performed and the first mask pattern P1 is formed to lower the angle a2 formed by the side surface and the horizontal plane, the third insulating portion M3 may be removed.

Fig. 8 is a schematic diagram of a mask metal film 110 according to an embodiment of the present invention.

The processes up to (a) of fig. 8 are the same as those described in (a) to (b) of fig. 6. However, fig. 8 (a) shows a comparison between the first mask pattern P1-1 and the first mask pattern P1-2, which are etched differently in the wet-etch WE1 of the first insulating portion M1.

Referring to fig. 8 (a), even though the same wet etching WEs 1-1 and WE1-2 occurs, different etching processes occur according to etching portions, as shown in the first mask pattern P1-1 and the first mask pattern P1-2. 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 such a difference in the pattern widths R2-1 and R2-2 adversely affects the resolution of the pixel.

Then, referring to fig. 8 (b), it can be confirmed that after the processes illustrated in fig. 6 (c) to 7 (f) are performed, the second insulation portions M2 "-1, M2" -2 may be formed on the vertically lower space of the first insulation portion M1, respectively. The sizes of the second insulation portions M2 "-1 and M2" -2 are different according to the size of the undercut space at the lower portion of the first insulation portion M1. Although the size of second insulating portion M2 ″ -1 is smaller than that of second insulating portion M2 ″ -2, the pattern widths of second insulating portions M2 ″ -1 and M2 ″ -2 are the same. The pattern width R3 of each of the second insulating portions M2 "-1, M2" -2 may be the same to correspond to the pattern width R3 of the first insulating portion M1.

Then, referring to fig. 8 (c), the second insulating portions M2 ″ -1 and M2 ″ -2 are used as masks for wet etching, and wet etching WE2 is performed, so that the second insulating portions can penetrate through the mask metal film 110. As a result, the deviation of the widths R1-1 and R1-2 of the formed second mask patterns P2-1 and P2-2 is significantly smaller than the deviation of the widths R2-1 and R2-2 of the first mask patterns P1-1 and P1-2. This is because the pattern width of the second insulating portions M2 "-1 and M2" -2, which are formed by performing the first wet etching of the mask metal film 110 to the depth of the first mask patterns P1-1 and P1-2 and then performing the second wet etching of the remaining thickness of the mask metal film 110, is substantially the same as the pattern width of the first insulating portion M1, which is formed by performing the first wet etching.

As described above, the mask manufacturing method of the present invention has an effect of forming the mask pattern P of a desired size by performing wet etching a plurality of times. Specifically, as part of the second insulating portion M2 ″ is left, the wet etching WE2 forming the second mask pattern P2 will be performed at a thinner width and a thinner thickness than the wet etching WE1, WE2 forming the first mask pattern P1, and thus has an advantage of easily controlling the width R1 of the second mask pattern P2. On the other hand, since the inclined surface can be formed by wet etching, the mask pattern P that can prevent the shadow effect can be formed.

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

The present invention may perform the formation process of the mask pattern P of fig. 6 to 7 after the mask metal film 110 is adhered to the stencil 50. The processes of (a), (b), (c) of fig. 9 correspond to the processes of (b), (c), (d) of fig. 4, and thus the description of the same parts will be omitted.

Referring to fig. 9 (a), the mask metal film 110 may be bonded to the template by interposing a temporary bonding portion 55. However, it should be prevented that the etching solution enters the interface between the mask metal film 110 and the temporary bonding portion 55 to damage the temporary bonding portion 55/the template 50 and cause an etching error of the mask pattern P. Thus, the mask metal film 110 can be bonded to the upper surface of the mask 50 in a state where the spacer insulating portion 23 is formed on one surface of the mask metal film 110. That is, the surface of the mask metal film 110 on which the spacer insulating portion 23 is formed may be directed to the upper surface of the mask 50. The mask metal film 110 and the stencil 50 may be bonded to each other by interposing the spacer insulating portion 23 and the temporary bonding portion 55.

The spacer insulating part 23 may be formed on the mask metal film 110 by a printing method or the like from a photoresist material that is not etched by an etching solution. In addition, in order to maintain a circular shape after a plurality of wet etching processes, the spacer insulating part 23 may include at least one of a cured negative photoresist, a negative photoresist containing epoxy resin. As an example, it is preferable to use an epoxy SU-8 photoresist or a black matrix photoresist (black matrix) and cure them together in the processes of baking the temporary bonding portion 55, baking the second insulating portion M2 (see fig. 7 (d)), and the like.

Then, referring to fig. 9 (b), a patterned insulating portion 25 may be formed on the mask metal film 110. The insulation part 25 corresponds to the insulation part 25 of fig. 5(d), or may correspond to the insulation parts M1, M2, and M3 of fig. 6 to 7.

Next, etching of the mask metal film 110 may be performed. The mask pattern P may be formed using the etching method of fig. 4(d) or the etching methods of fig. 6 to 7.

Then, referring to fig. 9 (c), the fabrication of the template 50 supporting the mask 100 may be completed by removing the insulating part 25. A mask supporting template including the mask 100/the spacer insulating part 23/the temporary bonding part 55/the template 50 may be manufactured.

The reason for manufacturing the mask supporting mask further including the spacer insulating portion 23 will be described in more detail below.

Fig. 10 is a schematic view of the etching degree of the mask metal film according to the comparative example and one embodiment of the present invention.

As shown in fig. 6 to 7, it is more advantageous to perform etching on only one side (e.g., the upper surface) of the mask metal film 110. If etching is performed simultaneously on both sides, the thickness of the mask metal film 110 may be uneven, and it may be difficult to obtain a desired form of the mask pattern P. It is important that wet etching WE is performed on one surface, and since wet etching is performed a plurality of times, the etching liquid does not leak to the other surface (for example, the lower surface) of the mask metal film 110.

Fig. 10(a) is a comparative example in which the mask metal film 110 is bonded to the template 50 with the temporary bonding section 55 interposed therebetween without the spacer insulating section 23. As detailed in (g) of fig. 7, since the thickness of the first mask pattern P1(P1-1, P1-2) is relatively thick and the width of the second mask pattern P2 defines the width of a pixel, the width of the second mask pattern P2 is preferably close to 0 μm.

Therefore, although the first mask pattern P1 is preferably formed to the maximum depth, even though the wet etches WE1-1 and WE1-2 are the same, the etching degree is different depending on the etching portion, as shown in the first mask pattern P1-1 and the first mask pattern P1-2'. Moreover, it is a very difficult process to maintain the minimum thickness by accurately controlling the etch WE1-1, WE1-2 rates. Like the first mask pattern P1-2' on the right side of fig. 10(a), the case of etching WE1-2 to the extent of forming the hole SN may occur.

In this case, the temporary bonding portion 55 exposed at the lower portion may be damaged (55- >55') by wet etching WE 1-2. The template 50 may be damaged in addition to the temporary bonding portion 55'.

In addition, when the etching liquid enters between the interface of the damaged temporary bonding portion 55 'and the mask metal film 110, WE1-2' may further etch the lower portion of the first mask pattern P1, thereby causing a problem that the size of the pattern is excessively formed or a local amorphous defect is generated.

Therefore, as shown in fig. 10 (b), in the present invention, by further interposing the spacer insulating section 23 between the mask metal film 110 and the temporary bonding section 55, even if the first mask pattern P1-2 forms the hole SN penetrating the mask metal film 110 during the first wet etching WE1(WE1-1, WE1-2), the etching liquid can be prevented from entering the lower surface of the mask metal film 110. Thus, the depth of the first mask pattern P1 can be formed deepest immediately before and after the hole SN is formed, and the etching liquid can be prevented from entering the lower surface of the mask metal film 110 even if the hole SN is formed.

The spacer insulating part 23 includes at least one of a cured negative photoresist, a negative photoresist containing an epoxy resin, and a black matrix photoresist (black matrix), and thus can withstand without being melted by an etching solution even if a subsequent etching process such as the first wet etching WE1 process, the second wet etching WE2, the third wet etching WE3, and the like is performed. Thus, even if the first mask pattern P1-2 penetrates the mask metal film 110, the width of the pattern is not enlarged and has an effect that the width corresponding to the 2-1 st insulating part M1 can be maintained.

In addition, as shown in fig. 10(c), on this basis, the present invention may further form an auxiliary insulating portion M4 having a width smaller than that of the first insulating portion M1 between the patterns of the first insulating portion M1. As shown in fig. 10 (b), even though the first mask pattern P1-2 'is formed at a depth at which the hole SN is formed, the first mask pattern P1-2' can be formed in the form of isotropic etching. Therefore, there is a problem that the taper angle becomes large in the lower portion of the mask metal film 110 which is the interface portion between the spacer insulating portion 23 and the mask metal film 110. Further, if the through hole SN is formed in the middle, the hole SN becomes excessively large while the etching degree toward the side surface of the hole SN is increased, and it is difficult to control the size of the mask pattern P.

Therefore, the present invention, as shown in fig. 10(c), penetrates the hole SN or the middle portion of the first mask pattern P1(P1-1, P1-2) later by further forming the auxiliary insulating portion M4 having a width smaller than that of the first insulating portion M1 between the patterns of the first insulating portion M1. The auxiliary insulating portion M4 is disposed between the patterns of the first insulating portion M1, so that it is possible to prevent the etching liquid from entering from the middle of the patterns of the first insulating portion M1 and to perform etching with the middle as a starting point. Thus, as indicated by a dotted line in fig. 10(c), an undercut may be formed by etching at two places (1) between the left first insulating portion M1 and the auxiliary insulating portion M4 and (2) between the auxiliary insulating portion M4 and the right first insulating portion M1. As a result, the starting point of the etching liquid entering becomes the left/right side of the auxiliary insulating part M4, and the first mask pattern P1(P1-1, P1-2) has a wider effect than the first mask patterns P1-1', P1-2' of fig. 10 (b). Meanwhile, since etching is performed to the extent that the hole SN is not formed or is formed later, the first mask pattern P1 can be formed at the maximum depth.

According to an embodiment, the shape of the auxiliary insulating portion M4 corresponding to the first insulating portion M1 may be formed in a circle, a polygon, or the like. The formation process of the auxiliary insulating portion M4 may be the same as the formation process of the first insulating portion M1 with only the pattern size being different. Of course, the auxiliary insulating portion M4 may be made of the same material as the first insulating portion M1.

Further, according to an embodiment, the auxiliary insulating part M4 may also be connected with the first insulating part M1. If the auxiliary insulating portion M4 is not connected to the first insulating portion M1, the portion of the mask metal film 110 supporting the auxiliary insulating portion M4 gradually disappears as the etching of the first mask pattern P1 proceeds, thereby causing the auxiliary insulating portion M4 to float on the etching solution. This may contaminate the etching solution or may be a factor that may adversely affect the pattern etching, and therefore, the first insulating layer M1 may be connected and fixed thereto. However, the form of the connection is preferably formed as a bridge (bridge) much smaller than the width of the auxiliary insulating portion M3, for example, a width of half or less.

Fig. 11 is an illustration of etch profiles for a mask metal film comparing a comparative example and according to an embodiment of the present invention. If (a1) of fig. 11 is the form of the first mask pattern P1-1' according to the comparative example and (a2) is the form of the first mask pattern P1-1 according to an embodiment of the present invention, (a1), (a2) will correspond to (b), (c) of fig. 10, respectively. FIG. 11 (b) is a schematic view showing the first mask patterns P1-1 and P1-1' of the two patterns being superimposed.

When it is necessary to form the first mask pattern P1-1 'at the maximum depth, (a1) of fig. 11, since isotropic etching proceeds toward the lower portion before the first mask pattern P1-1' has not reached to form a sufficient width to the side, there is a risk of forming the hole SN. If the through hole SN is formed in the middle and isotropic etching is performed, a problem arises in that the taper angle rapidly increases. Further, if the size of SN is too large, there is no etching target in the subsequent process of forming the second insulating portion M2 and performing the second etching WE, and thus it is difficult to form the second mask pattern P2 with a desired size and shape. In addition, the etching liquid WE1-2' flowing through the large hole SN also affects the temporary bonding portion 55 and the separator insulating portion 23 of the template 50.

Referring to (a2) and (b) of fig. 11, since the starting point of the first mask pattern P1-1, where the etching liquid enters, is located at two positions on the left and right sides of the auxiliary insulating portion M4, the diameter of the semi-circular shape (see the dotted line in fig. 10 (c)) in which the isotropic etching is performed is reduced. Accordingly, while the first mask pattern P1-1 is formed to have a larger width to the side, the depth can be relatively easily adjusted, thereby enabling to leave no hole SN or only as thin a thickness as possible.

Referring to (b) of fig. 11 comparing the comparative example and the embodiment of the present invention, it can be found that the etching profile of the present invention is changed and the first mask pattern P1-1 is etched deeper and wider. The thicknesses t1, t2 of the mask metal film 110 corresponding to the vertical regions between the first insulating M1 patterns after the WE1 is first etched are also reduced compared to the comparative example. Thus, after the second etching WE2, the thicknesses t1, t2[ step height; SH (mask thickness on both sides of the lower portion of the mask pattern). As the height of the sill is reduced, the height portion where the shadow effect is generated is reduced as much as possible, and the effect of easily adjusting the taper angle is obtained.

Fig. 12 is an SEM photograph for showing etching forms of the mask metal film according to the comparative example and the embodiment of the present invention.

Comparing the comparative example of fig. 12(a) with the embodiment of the present invention of fig. 12(b), it can be found that the first mask pattern P1 of the present invention is deeper and wider. It can be found that, after the first wet etching WE1, the upper width of the first mask pattern P1 is 46.19 μm, the thickness of the mask metal film 110 is 15.22 μm, and the lower width of the first mask pattern P1 has the sill heights t1, t2 of 3.13 μm, 3.69 μm with respect to 25 μm.

Fig. 13 is a graph for showing the residual thickness of the mask metal film 110, the sill heights t1, t2 of the comparative example and according to an embodiment of the present invention. The comparative example is shown as 1 and the inventive example as 2.

It can be seen that the sill of the comparative example has an average height of about 3.5 μm, whereas the sill of the present invention has an average height of about 2.7 μm, which is lower. As for the residual thickness, although the comparative example appears thinner, it is confirmed that this is because the comparative example is etched to such an extent that the hole SN is formed immediately, and thus the thickness of the comparative example is thinner than that of the present invention.

Fig. 14 is a graph for showing the residual thickness of the mask metal film, the Step height, the first insulation pattern interval, and the auxiliary insulation pattern interval according to an embodiment of the present invention. The thickness of the first mask pattern P1 is denoted by depth, the sill height is denoted by SH, the first insulating portion M1 pattern interval is denoted by outer, and the auxiliary insulating portion M4 pattern interval is denoted by inner.

Referring to fig. 14, it can be seen that when the interval between the patterns of the first insulating portion M1 is about 26 μ M to 34 μ M and the width of the auxiliary insulating portion M4 is 12 μ M to 16 μ M, the sill height appears to be thinner than 4 μ M. The threshold height may correspond to the thicknesses t1 and t2 of the mask metal film 110 corresponding to the vertical regions between the first insulating M1 patterns after the formation process of the first mask pattern P1.

Fig. 14 shows an optimum value range in which the first mask pattern P1 is formed to have the maximum thickness and the mask metal film 110 remains thin, in a four-step modification. When the pattern interval outer of the first insulating portion M1 is 26.5 to 30.5 μ M and the pattern interval inner of the auxiliary insulating portion M4 is 14 to 16 μ M, the sill height SH is the lowest, which is the optimum value for the interval.

Fig. 15 is a schematic view illustrating a process of manufacturing the mask 100 next to fig. 11.

Referring to fig. 15(a), after the first mask pattern P1 having the hole SN is formed, a second insulation part M2 ″ may be formed at a side of the first mask pattern P1 [ refer to (f) of fig. 7 ]. Next, wet etching WE2 may be performed on the first mask pattern P1.

The auxiliary insulation portion M4 may be removed after the first mask pattern P1 is formed.

The wet etching liquid may permeate the spaces between the first insulating M1 patterns and the spaces of the first mask pattern P1 and perform wet etching WE 2. The insulating portion M2 ″ formed in the first mask pattern P1 blocks the etching liquid to prevent the etching liquid from etching in the side surface direction of the first mask pattern P1, but in the lower surface direction of the first mask pattern P1.

Referring to fig. 15 (b), the second mask pattern P2 may be formed to penetrate the mask metal film 110. That is, the second mask pattern P2 may be formed to penetrate the other surface of the mask metal film 110 from the lower end of the first mask pattern P1.

In this case, the second mask pattern P2 may have both side surfaces not formed with a concave curvature, unlike those illustrated in fig. 7 (g) and (h). The first mask pattern P1 may have holes SN formed therein, or the second mask pattern P2 may have a shape as shown in the drawing because the mask metal film 110 has a spacer insulating part 23 at a lower portion thereof.

The reason why the second mask pattern P2 is as shown in fig. 15 (b) is as follows. In the state where the hole SN is formed, the local thickness of the mask metal film 110 exposed around the SN is very thin. Further, the exposed portion of the mask metal film 110 has a smaller curvature and is closer to a horizontal shape than the unexposed portion. Thus, the portion around the hole SN is etched WE2' with a thinner thickness and is removed first, and as the side of the removed portion is exposed, the side can be further etched. The wet etching is performed isotropically, and the feature that the etching rate in the width direction (or the side direction) is larger than the etching degree in the downward direction [ similarly to PD1- > PD2 in fig. 5(d) ] can also work together.

As another aspect, the second insulating portion M2 ″ may not necessarily correspond to the vertically lower position of the first insulating portion M1, and may be formed to a further lower position along the side of the first mask pattern P1. When the exposure L is performed in fig. 7 (e), at least the corner portion of the second insulating portion M2 ″ exposed through the gap between the first insulating portions M1 cannot be exposed due to the depth of the first mask pattern P1. The second insulation portion M2 ″ is formed closer to the lower portion due to the partial retention. Further, in order to more accurately control the size of the second mask pattern P2, the second insulating portion M2 ″ may be formed by performing exposure and development on a targeted basis. Next, WE2 may be etched on a portion of the mask metal film 110 exposed from the space between the second insulating portions M2 ″ formed at a lower position along the side surface of the first mask pattern P1. The mask metal film 110 of the vertically lower portion of the second insulating portion M2 ″ may then take an undercut shape due to being isotropically etched. Since the gap between the second insulating portion M2 ″ and the spacer insulating portion 23 is small, more etching liquid flows into the lower portion than the upper portion or the middle portion of the mask metal film 110 positioned below the second insulating portion M2 ″. Therefore, the undercut of the mask metal film 110 located under the second insulating portion M2 ″ does not exhibit a concave curvature but exhibits a form having a convex curvature or being close to a straight line.

FIG. 16 is a schematic diagram of a mask according to an embodiment of the invention.

Referring to fig. 16, the mask pattern P includes an upper first mask pattern P1 and a lower second mask pattern P2, and a thickness of the first mask pattern P1 may be greater than a thickness of the second mask pattern P2.

As a result of isotropic etching of the first mask pattern P1, both side surfaces are formed with concave curvatures. Both side surfaces of the second mask pattern P2 do not have a concave curvature but may have a convex curvature or a shape close to a straight line.

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 less than the lower width D2 of the second mask pattern P2. Accordingly, the side sectional shape of the mask pattern P may exhibit a bead shape similar to water dropped on the ground.

An angle ta formed by an imaginary straight line connecting the upper end corner of the first mask pattern P1 to the lower end corner of the first mask pattern P1 and the lower face of the mask may be less than 60 ° and more than 0, preferably less than 55 °. Since both side surfaces of the second mask pattern P2 have convex curvatures, an imaginary straight line should be arranged to contact the lower end corner of the first mask pattern P1 instead of the lower end corner of the second mask pattern P2. Thus, the sum of the shapes of the first and second mask patterns P1 and P2, i.e., the shape of the mask pattern P, may be tapered or reverse tapered as a whole.

Next, a process of bonding the mask 100 to the frame 200 using the manufactured mask supporting template 50 will be described.

Fig. 17 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. Fig. 12 illustrates a case where one mask 100 is attached to the cell region CR, but a plurality of masks 100 may be simultaneously attached to all the cell regions CR so that the masks 100 are attached to the frame 200. In this case, there may be a plurality of templates 50 for supporting a plurality of masks 100, respectively.

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 vacuum chuck 90 does not affect the adhesion state and alignment state of the mask 100 even when the template 50 is transferred to the frame 200 after the template 50 is sucked and turned over.

Then, referring to fig. 17, the mask 100 may correspond to one mask unit region CR of the frame 200. The correspondence of the mask 100 with the mask unit region CR may be achieved by loading the stencil 50 on 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 mask 100 is pressed by the mask 50, the mask 100 and the frame 200 can be closely abutted.

In addition, the lower support 70 may be further disposed at the lower portion of the frame 200. The lower support 70 may press the opposite side 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 unit sheet 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 may be irradiated with laser light L and the mask 100 may be attached to the frame 200 based on the laser welding. The welding portion of the mask laser-welded generates a welding bead WB, which may have the same material as the mask 100/frame 200 and be integrally connected with the mask 100/frame 200.

Fig. 18 is a schematic view of a process of separating the mask 100 from the template 50 after attaching the mask 100 to the frame 200 according to an embodiment of the present invention.

Referring to fig. 18, after the mask 100 is attached to the frame 200, the mask 100 and the stencil 50 may be separated (bonding). The mask 100 and the template 50 may be separated by at least 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 remains attached to the frame 200, only the stencil 50 may be lifted. As an example, if heat ET at a temperature higher than 85-100 ℃ is applied, the adhesiveness of the temporary bonding portion 55 is reduced, 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 adhesive portion 55 in a chemical such as IPA, acetone, ethanol, or the like, in order to melt, remove, or the like the temporary adhesive portion 55. As another example, the adhesion force of the mask 100 and the template 50 is weakened by applying the ultrasonic waves US or applying the ultraviolet rays UV, so that the mask 100 and the template 50 can be separated.

Fig. 19 is a schematic view of a state where the mask 100 is attached to the frame 200 and the insulating part 23 is removed, according to an embodiment of the present invention. Fig. 19 shows a state where all the masks 100 are attached to the cell regions CR of the frame 200. 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 stencil 50 is separated from the mask 100 by the vacuum chuck 90, and the spacer insulating portion 23 will remain on the upper surface of the mask 100. If the diaphragm insulating part 23 is a cured photoresist, it is difficult to remove by a wet etching process. Therefore, in order to remove the spacer insulating part 23 on the mask 100, at least one of the plasma PS and the ultraviolet ray UV may be applied. The process of removing only the spacer insulating portion 23 by applying the atmospheric pressure plasma or the vacuum plasma PS or the ultraviolet UV after loading the frame-integrated masks 100 and 200 into another chamber (not shown) may be performed.

As described above, the present invention enables the first mask pattern P1 to be formed at the maximum depth while leaving the threshold at the thinnest thickness, and thus has the effect of enabling more precise control of the size and position when finally forming the mask pattern P. In addition, by using the mask supporting template including the mask metal film 110/the spacer insulating part 23/the temporary bonding part 55/the template 50, there is an effect that an error due to penetration/leakage of an etching solution in a wet etching process can be prevented.

As described above, although the preferred embodiments of the present invention have been described with reference to the accompanying drawings, the present invention is not limited by the embodiments, and various modifications and changes can be made by those skilled in the art without departing from the spirit of the present invention. Such modifications and variations are considered to be within the purview and scope of the invention and the appended claims.