CN113737127B

CN113737127B - Mask manufacturing method, mask support template manufacturing method, and frame-integrated mask manufacturing method

Info

Publication number: CN113737127B
Application number: CN202110577931.8A
Authority: CN
Inventors: 李炳一; 金奉辰; 金辉寿
Original assignee: Wulaomao Materials Co ltd
Current assignee: Wulaomao Materials Co ltd
Priority date: 2020-05-27
Filing date: 2021-05-26
Publication date: 2024-03-08
Anticipated expiration: 2041-05-26
Also published as: TW202147666A; CN113737127A

Abstract

The present invention relates to a method for manufacturing a mask, a method for manufacturing a mask support 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 side of the mask metal film by wet etching; (c) Forming a second insulating portion at least in the first mask pattern located at a vertically lower portion of the first insulating portion; (d) A step of forming a second mask pattern penetrating from the first mask pattern to the other surface of the mask metal film by wet etching on one surface of the mask metal film; in step (a), an auxiliary insulating portion having a width smaller than that of the first insulating portion is further formed between the first insulating portion patterns.

Description

Mask manufacturing method, mask support template manufacturing method, and frame-integrated mask manufacturing method

Technical Field

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

Background

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

A conventional mask manufacturing method prepares a metal thin plate used as a mask, performs PR coating on the metal thin plate, then performs patterning or PR coating to have a pattern, and then manufactures a patterned mask by etching. However, in order to prevent Shadow Effect (Shadow Effect), it is difficult to Taper the mask pattern obliquely (Taper), and an additional process needs to be performed, thus resulting in an increase in process time, cost, and a decrease in productivity.

In ultra-high quality OLEDs, the current QHD image quality is 500-600PPI (pixel per inch), the size of the pixel reaches about 30-50 μm, and 4KUHD, 8KUHD high image quality has higher resolution of-860 PPI, -1600PPI, etc. Therefore, development of a technique capable of precisely adjusting the size of the mask pattern is urgently required.

In addition, in the conventional OLED manufacturing process, after the mask is manufactured in a bar shape, a plate shape, or the like, the mask is welded and fixed to the OLED pixel deposition frame and used. To manufacture a large area OLED, a plurality of masks may be fixed to the 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 in that alignment between masks and between mask units is not good. In addition, in the process of welding and fixing the mask to the frame, the mask film is too thin and large in area, so that there is a problem in that the mask sags or warps due to the load.

As such, considering the pixel size of the OLED with ultra-high image quality, it is necessary to reduce the alignment error between the units by about several μm, and exceeding this error may cause a defective product, so the yield may be extremely low. Therefore, there is a need 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 occurring in 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 support template, and a method for manufacturing a frame-integrated mask, which can accurately control the size of a mask pattern.

Technical proposal

The above object of the present invention can be achieved by a method of manufacturing a mask, the method 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 side of the mask metal film by wet etching; (c) Forming a second insulating portion at least in the first mask pattern located at a vertically lower portion of the first insulating portion; (d) A step of forming a second mask pattern penetrating from the first mask pattern to the other surface of the mask metal film by wet etching on one surface of the mask metal film; in step (a), an auxiliary insulating portion having a width smaller than that of the first insulating portion is further formed between the first insulating portion 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 parts is 26 μm to 34 μm and the width of the auxiliary insulating part is 12 μm to 16 μm, the thickness of the mask metal film corresponding to the vertical region between the first insulating part patterns after step (b) is at least less than 4 μm and exceeds 0.

Step (c) may comprise: (c1) Filling at least the second insulating portion in the first mask pattern; (c2) Volatilizing at least a part of the second insulating portion by baking; (c3) Exposing the upper portion of the first insulating portion and leaving only the second insulating portion located vertically below the first insulating portion.

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

Furthermore, the above object of the present invention can be achieved by a method of manufacturing a mask support template, the method comprising: (a) A step of adhering a mask metal film to an upper face of the template; (b) A step of forming a mask pattern on the mask metal film and manufacturing a mask; step (b) comprises: (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) Forming a second insulating portion at least in the first mask pattern located at a vertically lower portion of 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 step (b 1), an auxiliary insulating portion having a width smaller than that of the first insulating portion is further formed between the first insulating portion patterns.

In step (a), the mask metal film may be adhered to the upper face of the template by sandwiching the separator insulating portion and the temporary adhesion portion.

The separator insulating part 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 comprising: (a) A step of adhering a mask metal film to an upper face of the template; (b) A step of forming a mask metal film and manufacturing a mask; (c) A step of loading a template onto a frame having at least one mask unit area so that the mask corresponds to the mask unit area of the frame; and (d) a step of attaching the mask to the frame, the step (b) comprising: (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) Forming a second insulating portion at least in the first mask pattern located at a vertically lower portion of the first insulating portion; (b4) A step of forming a second mask pattern penetrating from the first mask pattern to the other surface of the mask metal film by wet etching on one surface of the mask metal film; in step (b 1), an auxiliary insulating portion having a width smaller than that of the first insulating portion is further formed between the first insulating portion 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 a 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 as described above, the present invention has an effect of being able to accurately control the size and position of the mask pattern.

Drawings

Fig. 1 is a schematic diagram of a prior art process of attaching a mask to a frame.

Fig. 2 is a front view and a side cross-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 support template according to an embodiment of the present invention.

Fig. 5 is a schematic view of 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 etching degree of a mask metal film according to an embodiment of the present invention.

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

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

Fig. 11 is a schematic diagram of comparative examples and etching patterns of a mask metal film according to an embodiment of the present invention.

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

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

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

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

Fig. 16 is a schematic diagram for displaying 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 diagram of a process of separating a mask and a stencil after attaching the mask to a frame in accordance with an embodiment of the 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 insulating part

25: insulation part

50: template

55: temporary bonding part

100: mask for mask

110: mask metal film

200: frame

C: unit, mask unit

CR: mask unit region

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

M4: auxiliary insulating part

P: mask pattern

P1, P1-2: first mask pattern

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

SN: hole(s)

WE1, WE2, WE3: wet etching

Detailed Description

The following detailed description of the invention refers to the accompanying drawings, which illustrate specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail 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 being different from each other and not mutually exclusive. For example, the particular shapes, structures and characteristics described herein may enable one embodiment to be implemented as other embodiments without departing from the spirit and scope of the invention. In addition, the location or arrangement of individual elements within each disclosed embodiment should be understood as 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. Like reference numerals in the drawings designate the same or similar functions through various aspects, and lengths, areas, thicknesses, 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 so as to enable those skilled in the art to easily practice the present invention.

Fig. 1 is a schematic diagram of a prior art process of attaching a mask 10 to a frame 20.

The existing mask 10 is a bar Type (Stick-Type) or Plate-Type (Plate-Type), and the bar Type mask 10 of fig. 1 may be used by welding both sides of the bar to the OLED pixel deposition frame. The mask 10 has a plurality of display cells C in a main Body (Body, or mask film 11). One unit C corresponds to one display of a smart phone or the like. The unit C has a pixel pattern P formed therein so as to correspond to each pixel of the display.

Referring to fig. 1 (a), tensile forces F1-F2 are applied along the long axis direction of the bar-type mask 10, and the bar-type mask 10 is loaded on the frame 20 of a square frame shape in an expanded state. The frame 20 may be of a size sufficient to locate the cells C1-C6 of one strip mask 10 in the interior void of the frame, or may be of a size sufficient to locate the cells C1-C6 of a plurality of strip masks 10 in the interior void of the frame.

Referring to fig. 1 (b), alignment is performed while trimming the tensile forces F1-F2 applied to each side of the bar-type mask 10, 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-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-F2 applied to the respective sides of the strip mask 10 are finely adjusted, a problem of poor alignment of the mask units C1-C3 with each other still occurs. For example, the distances between the patterns P of the cells C1 to C6 are different from each other or the patterns P are skewed. Since the stripe type mask 10 has a large area including a plurality of cells C1 to C6 and has a very thin thickness of several tens of μm, sagging or twisting due to a load is easy. In addition, it is a very difficult task to confirm the alignment state between the respective units C1 to C6 in real time by a microscope while adjusting the tensile force F1 to F2 to make all the respective units C1 to C6 flat. However, in order to avoid the mask pattern P having a size of several μm to several tens of μm from adversely affecting the pixel process of the ultra-high image quality OLED, the alignment error is preferably not more than 3 μm. The alignment error between such adjacent cells is referred to as pixel positioning accuracy (pixel position accuracy, PPA).

Further, it is very difficult to attach each of the strip masks 10 to one frame 20, and to precisely align the alignment between the plurality of strip masks 10 and between the plurality of cells C-C6 of the strip masks 10, and only increases the process time based on the alignment, which is an important cause of decreasing the production efficiency.

In addition, after the bar mask 10 is attached and fixed to the frame 20, the tensile forces F1-F2 applied to the bar mask 10 act as tensile forces in opposite directions on the frame 20. This tension may cause a minute deformation of the frame 20 and a distortion of the alignment state between the plurality of cells C1 to C6 may occur.

In view of this, the present invention proposes a frame 200 and a frame-integrated mask that can form the mask 100 and the frame 200 into a single structure. The mask 100 integrally formed with the frame 200 can not only prevent sagging or distortion, etc., but also be accurately aligned with the frame 200.

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

Next, the present specification describes the configuration of the frame-integrated mask, but the structure and manufacturing process of the frame-integrated mask can 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 one frame 200. In other words, the plurality of masks 100 are attached to the frame 200. In the following, for convenience of explanation, the rectangular mask 100 is taken as an example, but before the mask 100 is attached to the frame 200, the mask may be a stripe-shaped mask having protrusions for clamping on both sides, and the protrusions may be removed after the mask is attached to the frame 200.

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

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

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

In addition, the frame 200 has a plurality of mask unit areas 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, a first grid sheet portion 223, and a second grid sheet portion 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 integrally formed with each other.

The thickness of the edge frame portion 210 may be greater than that of the mask unit sheet portion 220, and may be formed in a thickness of several mm to several cm. The thickness of the mask unit sheet portion 220 is thinner than that of the edge frame portion 210, but thicker than the mask 100, and may be about 0.1mm to 1mm. The width of the first and second grid sheet portions 223, 225 may be about 1-5mm.

In the planar sheet, a plurality of mask unit regions CR (CR 11 to CR 56) may be provided in addition to the regions occupied by the edge sheet portion 221, the first grid sheet portion 223, and the second grid sheet portion 225.

The mask 200 has a plurality of mask unit regions CR, and each mask 100 can be attached so that each mask unit C corresponds to each mask unit region CR. The mask unit C corresponds to the mask unit region CR of the frame 200, and part or all of the dummy portion may be attached to the frame 200 (mask unit sheet portion 220). Thus, the mask 100 and the frame 200 may form a unitary 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 unit 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 all of the dummy portion DM may be attached to the frame 200 (the mask unit sheet portion 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 (CR 11 to CR 56), a plurality of masks 100 including mask units C (C11 to C56) corresponding to the respective mask unit regions CR (CR 11 to CR 56) may be provided. Further, a plurality of templates 50 for supporting a plurality of masks 100, which will be described later, are provided.

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

Referring to fig. 4 (a), a template (template) 50 may be provided. The template 50 is a medium to which the mask 100 is attached on one side and moves the mask 100 in a state of supporting the mask 100. The center portion 50a may correspond to the mask unit 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), heat-resistant glass, quartz (quartz), alumina (Al) ₂ O ₃ ) And borosilicate glass (borosilicate glass), zirconia (zirconia), and the like. As an example, the template 50 may use borosilicate glass having excellent heat resistance, chemical resistance, mechanical strength, transparency, etc 33, and a material of the same. Furthermore, the->33 is about 3.3, and is not significantly different from the invar mask metal film 110, which has the 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 template 50 to reach the welding portion WP (the region where welding is performed) of the mask 100, a laser passing hole 51 may be formed on the template 50. The laser passing holes 51 can be formed in the die plate 50 so as to correspond to the positions and the number of the welding portions WP. Since the plurality of welding portions WP are arranged at predetermined intervals on the edge of the mask 100 or the dummy portion DM portion, the plurality of laser passing holes 51 may be formed at predetermined intervals correspondingly thereto. As an example, since the plurality of solder portions WP are arranged at predetermined intervals on the both sides (left/right) dummy portion DM portions of the mask 100, the laser passing holes 51 may also be formed at predetermined intervals on both sides (left/right) of the stencil 50.

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

One side of the template 50 may form a temporary bond 55. The temporary bonding portion 55 may temporarily attach the mask 100 (or the mask metal film 110') to one side of the template 50 and support the template 50 before the mask 100 is attached to the frame 200.

The temporary bonding portion 55 may use an adhesive or a bonding sheet separable based on heating and an adhesive or a bonding sheet separable based on irradiation UV.

As an example, the temporary bonding portion 55 may use liquid wax (liquid wax). The liquid wax may use the same wax as that used in the polishing step of a semiconductor wafer or the like, and the type thereof is not particularly limited. As a resin component mainly used for controlling the adhesive force, impact resistance, and the like with respect to the maintenance force, 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 acrylonitrile-butadiene rubber (ABR, acrylonitrile butadiene rubber) as a resin component and skyliquidambar-4016 containing n-propanol as a 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 a liquid wax, is decreased in viscosity at a temperature higher than 85 deg.c to 100 deg.c and increased in viscosity at a temperature lower than 85 deg.c, and a portion is solidified to be solid, so that the mask metal film 110' can be fixedly bonded to the stencil 50.

Next, referring to (b) of fig. 4, a mask metal film 110 may be adhered on the template 50. The liquid wax may be heated to above 85 ℃ and the mask metal film 110 contacted to the stencil 50, after which the mask metal film 110 and the stencil 50 are passed between rollers for adhesion.

According to an embodiment, baking (baking) is performed on the mold 50 at about 120 ℃ for 60 seconds, so that the mask metal film lamination (lamination) process may be performed immediately after the solvent of the temporary bonding portion 55 is gasified. Lamination is performed by loading the mask metal film 110 on the template 50 having the temporary bonding portion 55 formed on one side 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 by sandwiching the temporary bonding portion 55.

As yet another example, the temporary bonding portion 55 may use a thermal release tape (thermal release tape). The thermal release tape may be in the form of a Core Film (Core Film) such as a PET Film disposed therebetween, a heat peelable adhesive layer (thermal release adhesive) disposed on both sides of the Core Film, and a release Film (release Film) disposed on the outer periphery of the adhesive layer. Here, the adhesive layers disposed on both sides of the core film may have mutually different peeling 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 peeling temperatures of the first adhesive layer and the second adhesive layer are different from each other, in fig. 18 described later, when the mask 50 is separated from the mask 100, the mask 100 can be separated from the mask 50 and the temporary bonding portion 55 by applying the heat for peeling the first adhesive layer.

In addition, the mask metal film 110 may use a mask metal film having one or both sides treated by 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. The surface defect removal process and the thickness reduction process may also be performed after the mask metal film 110 is bonded to the template 50. In addition, the thickness reduction process may be performed only for the mask unit C portion. After the surface defect removal process such as CMP, an insulating portion (not shown) such as a photoresist is formed only in a region corresponding to the solder 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 solder portion WP of the mask metal film 110 in a state where the mask metal film 110 is adhesively supported on the template 50, an etching process for reducing the thickness is performed on the mask unit C portion, so that the solder portion WP is formed thicker and a step difference is generated with the mask unit C, and the surface of the mask unit C portion for forming the mask pattern P may be formed in a defect-free state.

Then, referring to (c) of fig. 4, 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, etching of the mask metal film 110 may be performed. The etching method is not particularly limited, and a dry etching method, a wet etching method, or the like may be used, and as a result of the 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 having a plurality of mask patterns P formed thereon 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 portion 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 diagram of etching degree (d) of a mask according to the conventional mask manufacturing process [ (a) to (c) ] and comparative example.

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

First, as shown in fig. 5 (a), a patterned photoresist M may be formed on a planarization film 110' (sheet). Then, as in (b) of fig. 5, wet etching WE may be performed through the spaces 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 required. Since wet etching WE proceeds isotropically, the etched pattern is approximately circular-arc-shaped. Further, since it is difficult to maintain the etching rate at each portion uniformly during wet etching WE, the widths R1', R1 ", R1 '" of the penetration pattern after penetrating the film 110' can be made different. In particular, in the pattern in which undercut UC (undercut) frequently occurs, not only the lower width r1″ of the mask pattern P ' is formed wider, but also the upper width r2″ is formed wider, and the lower widths R1', R1' "and the upper widths R2', R2 '" in the pattern in which undercut UC is less generated are formed narrower relatively.

As a result, the conventional mask 100 'has a problem in that the sizes of the respective mask patterns P' are not uniform. In the case of ultra-high quality OLEDs, the current QHD image quality is 500-600PPI, the pixel size reaches about 30-50 μm, and 4KUHD, 8KUHD high image quality has higher resolution than it, such as-860 PPI, -1600PPI, etc., so fine size differences may also lead to poor products.

Referring to fig. 5 (d), since wet etching WE proceeds isotropically, the etched pattern assumes a substantially circular arc shape. In addition, in performing wet etching, it is difficult for the respective partial etches to be identical, and if the mask metal film 110 is penetrated by only 1 wet etching to form a mask pattern, the deviation thereof may be greater. For example, although the wet etching speeds of the mask pattern 111 and the mask pattern 112 are different, the difference in upper width (undercut) is not large. However, the difference between the lower width PD1 of the mask metal film 110 penetrated by forming the mask pattern 111 and the lower width PD2 of the mask metal film 110 penetrated by forming the mask pattern 112 is much larger than the difference of the upper widths. This is a result of wet etching proceeding isotropically. In other words, the widths determining the pixel size are the lower widths PD1, PD2 of the mask patterns 111, 112, not the upper widths, and thus, a scheme of controlling the lower widths PD1, PD2 using a wet etching method other than 1 wet etching may be considered.

Thus, according to an aspect of the present invention, the accuracy of the mask pattern during wet etching can be improved by multiple wet etches.

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

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

Then, referring to (b) of fig. 6, 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 by including the hole SN in the present invention described with reference to fig. 11. For ease of illustration, the hole portions are excluded from the illustration 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 may have a width wider than the inter-pattern pitch R3 of the first insulating portion M1 because the width R2 of the first mask pattern P1 is different from the inter-pattern pitch R3 of the first insulating portion M1 due to the isotropic etching characteristic. In other words, since the undercuts UC (undercut) are formed at both lower portions of the first insulating portion M1, the width R2 of the first mask pattern P1' may be more than the pitch R3 between patterns of the first insulating portion M1 by the width at which the undercuts UC are formed.

Then, 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 insulation portion M2 may be formed of a photoresist material by a printing method or the like. As for the second insulating portion M2, since it needs to remain in a space where an undercut UC is formed, which will be described later, a positive type photoresist material is preferable.

Since the second insulation portion M2 is formed on one surface (upper surface) of the mask metal film 110, a portion is formed on the first insulation portion M1, and another portion is filled inside the first mask pattern P1.

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

Then, referring to (d) of fig. 7, a portion of the second insulation portion M2 may be removed. As an example, a portion of the second insulating portion M2 may be removed in a volatilized form by baking (baking). The solvent of the second insulating portion M2 is volatilized by the baking process and only the photoresist composition remains. Accordingly, the second insulation part M2' leaves a thinner portion, such as a coated film, at the exposed portion of the first mask pattern P1 and the surface of the first insulation part M1. The thickness of the remaining second insulating portion M2' is preferably less than about several μm 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 upper portion of the first insulation portion M1 is exposed L, the first insulation 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 having a metal plating film formed thereon, the light shielding effect is excellent. Therefore, the second insulating portion M2″ located at the vertically lower portion of the first insulating portion M1 [ refer to (f) of fig. 7 ] 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, a portion of the second insulating portion M2″ that is not exposed L is left, and other second insulating portions M2' are removed. Since the second insulation portion M2' is a positive photoresist, a portion of the exposure L is removed. The space reserved by the second insulation portion M2″ can correspond to a space in which the undercut UC [ refer to step (b) of fig. 6 ] is formed at both side lower portions of the first insulation portion M1.

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

At this time, the second insulating portion m2″ remains on the first mask pattern P1. The remaining second insulation 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 direction of the first mask pattern P1, but performs 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 vertical 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 for the pitch R3 between the patterns of the first insulating portion M1. Accordingly, the width R1 of the second mask pattern P2 may be smaller 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 too thick, it is difficult to control the width R1 of the second mask pattern P2, and uniformity of the width R1 is degraded, the shape of the mask pattern P as a whole may not be tapered/inverted tapered, and thus 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, more preferably 0.5 to 2.0 μm.

The sum of the shapes of the connected first mask pattern P1 and second mask pattern 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 up, the taper or the reverse taper is exhibited as a whole.

In addition, between steps (b) and (c) of fig. 6, steps (b 2) and (b 3) may also be performed.

Referring to (b 2) of fig. 6, a third insulation portion 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 the width R3 may be formed in the interval of the patterns of the adjacent pair of first insulating portions M1, i.e., on the first mask pattern P1'.

For ease of exposure, the third insulating portion M3 preferably uses a negative type (negative type) photoresist material. When the negative photoresist is filled in the first mask pattern P1' 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 only the third insulating portion M3 exposed between the patterns of the first insulating portion M1 may be left. At this time, as illustrated in fig. 6 (c), a third edge portion M3 having a width R3 may be formed on the first mask pattern P1'.

Then, referring to (b 3) of fig. 6, the first mask pattern P1' may be further wet etched WE2. Since the third insulating portion M3 is formed in a part of the first mask pattern P1', the first mask pattern P1' is not etched further downward but is etched in the lateral direction. Accordingly, the width of the first mask pattern P1 'may be greater than R2 (P1' - > P1).

The specific reason for performing steps (b 2) and (b 3) of fig. 6 is as follows.

If the steps (b 2) and (b 3) of fig. 6 are omitted and the first mask pattern P2 is formed after the first mask pattern P1' is formed, it may be difficult to reduce the taper angle of the mask pattern P ' (P1 ', P2). Based on the features of the isotropic etching process of the first mask pattern P1', the side surface hardly has a small angle (angle formed by the horizontal plane and the side of the mask pattern), and since the angle exceeds 60 ° or is nearly vertical, there is a case where the angle exceeds 70 ° even if the wet etching is performed twice. In general, 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 respect to the horizontal plane, and if the above angle is exceeded, the Shadow Effect is still generated, resulting in difficulty in uniformly forming the OLED pixels.

In addition, in order to form the surface of the mask pattern P not to be rough and uniformly, the wet etching process needs to be performed in a short time. However, if the wet etching process is performed in a short time, it is difficult for the first mask pattern P1' side angle to form a small angle. Finally, if the time of the wet etching process is prolonged in order to make the side angle of the first mask pattern P1' a small angle, there is 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 in the side direction of the first mask pattern P1', the angle (a 1- > a 2) formed between the side surface of the first mask pattern P1 and the horizontal plane can be reduced. Since the first mask pattern P1 is formed by performing wet etching twice, each etching process does not need to last for a long time, and thus 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 reduce an angle a2 formed between 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 process up to (a) of fig. 8 is the same as the process described in (a) to (b) of fig. 6. However, in fig. 8 (a), the first mask pattern P1-1 and the first mask pattern P1-2 having different etching degrees in the wet etching WE1 of the first insulating portion M1 are described in comparison.

Referring to fig. 8 (a), even though wet etching WE1-1 and WE1-2 is the same, etching processes with different degrees occur depending on the etching portions, as shown by 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 pattern widths R2-1, R2-2 will have a bad influence on the resolution of the pixels.

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

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

As described above, the mask manufacturing method of the present invention has an effect that the mask pattern P of a desired size can be formed by performing wet etching a plurality of times. Specifically, as a portion of the second insulating portion M2″ is left, the wet etching WE2 forming the second mask pattern P2 will be performed over 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 easy control of 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 which can prevent a shadow effect can be formed.

The present invention may perform the formation process of the mask pattern P of fig. 6 to 7 after bonding the mask metal film 110 to the template 50. The processes of (a), (b), and (c) of fig. 9 correspond to the processes of (b), (c), and (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 adhered to the template by sandwiching the temporary adhesion part 55. However, the etching liquid should be prevented from entering the interface of the mask metal film 110 and the temporary bonding portion 55 to damage the temporary bonding portion 55/the template 50 and thus cause etching errors of the mask pattern P. Thereby, the mask metal film 110 can be bonded to the upper face of the template 50 in a state where the separator insulation portion 23 is formed on one face of the mask metal film 110. That is, the mask metal film 110 formed with the separator insulating portion 23 may be directed toward the upper face of the stencil 50. The mask metal film 110 and the stencil 50 may be bonded to each other by sandwiching the separator insulating portion 23 and the temporary bonding portion 55.

The spacer insulating portion 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 separator insulating part 23 may include at least one of a cured negative photoresist, a negative photoresist containing an epoxy resin. As an example, an epoxy SU-8 photoresist or a black matrix photoresist (black matrix) is preferably used, so that it is cured together during baking of the temporary bonding portion 55, baking of the second insulating portion M2 (see fig. 7 (d)), and the like.

Then, referring to (b) of fig. 9, a patterned insulating portion 25 may be formed on the mask metal film 110. The insulating portion 25 corresponds to the insulating portion 25 of fig. 5 (d), or may correspond to the insulating portions 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 portion 25. A mask support template including the mask 100/the separator insulating portion 23/the temporary bonding portion 55/the template 50 may be manufactured.

Next, the reason for manufacturing the mask support template further including the separator insulating portion 23 will be described in more detail.

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

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

Fig. 10 (a) is a comparative example in which the mask metal film 110 is bonded to the template 50 with the temporary bonding portion 55 interposed therebetween in the case of the separator-less insulating portion 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 the 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 at the maximum depth, even if wet etching WE1-1, WE1-2 is the same, the etching degree may be 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 a minimum thickness by accurately controlling the etching WE1-1, WE1-2 speed. As in the case of the first mask pattern P1-2' on the right side of fig. 10 (a), etching WE1-2 to the extent that the hole SN is formed 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. In addition to the temporary bond 55', the form 50 may also be damaged.

In addition, when the etching solution 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 pattern is oversized or partially amorphous defects.

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

The separator insulating part 23 is able to withstand and not be melted by the etching liquid even if the subsequent etching processes such as the first wet etching WE1 process, the second wet etching WE2, the third wet etching WE3 and the like are performed, since it includes at least one of a cured negative photoresist, a negative photoresist containing an epoxy resin, and a black matrix photoresist (black matrix). Thus, even if the first mask pattern P1-2 penetrates the mask metal film 110, the width of the pattern is not enlarged, and the effect of keeping the width of the 2-1 insulating portion M1 corresponding thereto can be obtained.

In addition, as shown in fig. 10 (c), 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 if 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 an isotropically etched form. Therefore, there is a possibility that the taper angle becomes large in the interface portion between the separator insulating portion 23 and the mask metal film 110, that is, in the lower portion of the mask metal film 110. Further, if the through hole SN is formed in the middle, the etching degree toward the side of the hole SN is increased and the hole SN is excessively increased, and thus the size of the mask pattern P is difficult to control.

Accordingly, in the present invention, as shown in fig. 10 (c), the hole SN or the middle portion of the first mask pattern P1 (P1-1, P1-2) is penetrated later by further forming the auxiliary insulating portion M4 having a smaller width than the first insulating portion M1 between the patterns of the first insulating portion M1. The auxiliary insulating portions M4 are disposed between the patterns of the first insulating portions M1, so that the etching liquid is prevented from entering from the middle of the patterns of the first insulating portions M1 and etching is performed starting from the middle. As a result, as indicated by a broken line in (c) of fig. 10, etching is performed at two places between (1) the left side first insulating portion M1 and the auxiliary insulating portion M4 and (2) the auxiliary insulating portion M4 and the right side first insulating portion M1, whereby undercut can be formed. As a result, the starting point of the etching liquid entering becomes the left/right side of the auxiliary insulating portion M4, so that the first mask pattern P1 (P1-1, P1-2) has an effect of a larger width than the first mask pattern P1-1', P1-2' of fig. 10 (b). Also, since etching is performed to such an 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 auxiliary insulating portion M4 may be formed in a circular shape, a polygonal shape, or the like corresponding to the shape of the first insulating portion M1. The formation process of the auxiliary insulating portion M4 may be the same as the formation process of the first insulating portion M1 and only the pattern size is different. Of course, the auxiliary insulating portion M4 may be made of the same material as the first insulating portion M1.

Furthermore, according to an embodiment, the auxiliary insulating portion M4 may also be connected to the first insulating portion 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 liquid. This contaminates the etching liquid or prevents pattern etching as a bad factor, and thus can be connected and fixed to the first insulating portion M1. However, the connection is preferably formed as a bridge (bridge) having a width substantially smaller than the width of the auxiliary insulating portion M3, for example, a width less than half.

Fig. 11 is an intention of etching forms of mask metal films used for comparative example and according to an embodiment of the present invention. If (a 1) of fig. 11 is the form of the first mask pattern P1-1' according to the comparative example, and (a 2) is the form of the first mask pattern P1-1 according to an embodiment of the present invention, then (a 1) and (a 2) will correspond to (b) and (c) of fig. 10, respectively. Fig. 11 (b) is a schematic diagram in which the first mask patterns P1-1 and P1-1' in two forms are superimposed.

When it is necessary to form the first mask pattern P1-1 'at the maximum depth, in fig. 11 (a 1), isotropic etching is performed downward before the first mask pattern P1-1' has not yet reached the formation of a sufficient width to the side, and thus 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 increases rapidly. Further, if the SN size becomes excessively large, the second mask pattern P2 of a desired size and shape is hardly formed because the etching target does not exist in the subsequent process, that is, in the case of forming the second insulating portion M2 and performing the second etching WE. In addition, the etching liquid WE1-2' flowing through the large hole SN also affects the temporary bonding portion 55 of the die plate 50 and the separator insulating portion 23.

Referring to fig. 11 (a 2) and (b), the diameter of the semicircle pattern (see the broken line of fig. 10 (c)) that is isotropically etched becomes smaller because the starting point of the etching liquid entering becomes two positions on the left/right side of the auxiliary insulating portion M4 with respect to the first mask pattern P1-1. 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, so that the hole SN can be not formed or only the thickness as thin as possible can be left.

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

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 was found that the upper width of the first mask pattern P1 after the first wet etching WE1 was 46.19 μm, the thickness of the mask metal film 110 was 15.22 μm, and the lower width of the first mask pattern P1 was 3.13 μm and 3.69 μm in the height t1 and t2 of the sill based on 25 μm.

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

It was found that the average height of the sill of the comparative example was about 3.5. Mu.m, whereas the average height of the sill of the present invention was about 2.7. Mu.m, and the height was low. Although the comparative example exhibited a thinner thickness for the residual thickness, it was confirmed that this was because the comparative example was etched to such an extent that the hole SN was immediately formed, so that the thickness of the comparative example was thinner than the present invention.

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

Referring to fig. 14, it can be found that when the interval between the patterns of the first insulation portions M1 is about 26 μm to 34 μm and the width of the auxiliary insulation portions M4 is 12 μm to 16 μm, the height of the mesa is thinner than 4 μm. The height of the mesa may correspond to thicknesses t1, t2 of the mask metal film 110 corresponding to the vertical region between the first insulation part M1 patterns after the first mask pattern P1 forming process.

Fig. 14 shows, by four variations, an optimum numerical range in which the first mask pattern P1 is formed at the maximum thickness and the mask metal film 110 remains at a relatively small thickness. When the pattern interval outer of the first insulation part M1 is 26.5 to 30.5 μm and the pattern interval inner of the auxiliary insulation part M4 is 14 to 16 μm, the sill height SH is the lowest, which is the best 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 forming the first mask pattern P1 having the hole SN, a second insulating portion M2″ may be formed at a side surface of the first mask pattern P1 [ refer to fig. 7 (f) ]. Next, wet etching WE2 may be performed on the first mask pattern P1.

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

The wet etching liquid may penetrate the spaces between the first insulating part M1 patterns and the first mask pattern P1 spaces and wet etch WE2. The insulating portion M2″ formed in the first mask pattern P1 shields the etching liquid to prevent the etching liquid from etching in the side direction of the first mask pattern P1, but etching 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.

At this time, the second mask pattern P2 may be different from those illustrated in fig. 7 (g) and (h), and both sides thereof may not have a concave curvature. The first mask pattern P1 may have a hole SN formed therein or the second mask pattern P2 may have a shape as shown in the drawing since the lower portion of the mask metal film 110 has a separator insulating portion 23.

The reason why the second mask pattern P2 is shown in fig. 15 (b) is as follows. If the hole SN is already formed, the local thickness of the mask metal film 110 exposed around SN is very thin. Further, the exposed portion of the mask metal film 110 has a shape having a smaller curvature and being more nearly horizontal than the unexposed portion. Thus, the portion around the hole SN is etched WE2' with a small thickness and removed first, and as the side surface of the removed portion is exposed, the side surface can be further etched. The wet etching proceeds isotropically, and features that the etching rate in the width direction (or the side direction) is greater than the etching degree in the downward direction [ similar to PD1- > PD2 of fig. 5 (d) ] can also work together.

As another aspect, the second insulating portion M2″ does not necessarily correspond to a vertically lower position of the first insulating portion M1, and may be formed to a lower position along the side of the first mask pattern P1. In the exposure L in fig. 7 (e), at least the corner portion of the second insulating portion M2″ exposed through the interval between the first insulating portions M1 cannot be exposed due to the depth of the first mask pattern P1. The second insulating portion m2″ is formed closer to the lower portion due to the partial remaining. 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 with pertinence. Next, the mask metal film 110 exposed from the space between the second insulating portions m2″ formed further down along the side surface of the first mask pattern P1 may be partially etched WE2. Then, the mask metal film 110 of the vertically lower portion of the second insulation portion m2″ may take an undercut shape due to isotropic etching. Since the gap between the second insulating portion M2 "and the separator 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 located in the lower portion of the second insulating portion M2". Therefore, the undercut of the mask metal film 110 located at the lower portion of the second insulating portion m2″ does not exhibit a concave curvature but exhibits a shape having a convex curvature or approaching 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 the thickness of the first mask pattern P1 may be greater than the thickness of the second mask pattern P2.

As a result of the isotropic etching of the first mask pattern P1, both side surfaces have concave curvatures. The 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. Further, the lower width D3 of the first mask pattern P1 (or the upper width D3 of the second mask pattern P2) may be smaller than the lower width D2 of the second mask pattern P2. Accordingly, the side sectional shape of the mask pattern P may take on a similar shape to a water droplet 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 sides of the second mask pattern P2 have a convex curvature, the virtual 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 mask pattern P1 and the second mask pattern P2, i.e., the shape of the mask pattern P, may take on a tapered shape or an inverted tapered shape as a whole.

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

Fig. 17 is a schematic view of a state in which the template 50 is loaded on the frame 200 and the mask 100 is corresponding to the cell region CR of the frame 200 according to an embodiment of the present invention. While fig. 12 illustrates a case where one mask 100 is mapped/attached to the cell regions CR, a plurality of masks 100 may be mapped to all the cell regions CR at the same time to attach the masks 100 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 transferred by a vacuum chuck 90. The vacuum chuck 90 may be used to suction and transfer the surface opposite to the surface of the template 50 to which the mask 100 is bonded. After the vacuum chuck 90 sucks the template 50 and turns over, the adhesion state and alignment state of the mask 100 are not affected during transferring the template 50 to the frame 200.

Then, referring to fig. 17, the mask 100 may be corresponding to one mask unit region CR of the frame 200. The mask 100 and the mask unit region CR can be associated by loading the template 50 on the frame 200 (or the mask unit sheet portion 220). The position of the template 50/vacuum chuck 90 is controlled while observing whether the mask 100 corresponds to the mask unit region CR through a microscope. Since the template 50 presses the mask 100, the mask 100 and the frame 200 may 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 surface of the mask unit region CR that is in contact with the mask 100. At the same time, since the lower support 70 and the template 50 press the edge of the mask 100 and the frame 200 (or the mask unit sheet portion 220) in mutually opposite directions, the aligned 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 laser welding. The welded portion of the mask welded by the laser generates a weld bead WB, which may be of the same material as the mask 100/frame 200 and integrally connected with the mask 100/frame 200.

Fig. 18 is a schematic diagram 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 attaching the mask 100 to the frame 200, the mask 100 and the template 50 may be separated (debonding). 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 template 50 may be lifted. As an example, if heat ET of higher than 85-100 ℃ is applied, the viscosity of the temporary bonding portion 55 is reduced, and the adhesive force of the mask 100 and the template 50 is weakened, so that the mask 100 and the template 50 may be separated. As another example, the mask 100 may be separated from the template 50 by immersing the temporary bonding portion 55 in a chemical such as IPA, acetone, ethanol, or the like to melt, remove, or the like the temporary bonding portion 55. As another example, the adhesive force of the mask 100 and the template 50 is weakened by applying ultrasonic waves US or applying ultraviolet rays UV, so that the mask 100 and the template 50 may be separated.

Fig. 19 is a schematic view of a state in which the mask 100 is attached to the frame 200 and the insulating portion 23 is removed according to an embodiment of the present invention. Fig. 19 shows a state in which all masks 100 are attached to the cell region CR of the frame 200. Although the templates 50 may be separated after attaching the masks 100 one by one, it is also possible to separate all the templates 50 after attaching all the masks 100.

The template 50 is separated from the mask 100 by the vacuum chuck 90, and the upper surface of the mask 100 will remain with the separator insulation 23. If the spacer insulating portion 23 is a cured photoresist, it is difficult to remove by a wet etching process. Therefore, in order to remove the spacer insulating portion 23 on the mask 100, at least one of plasma PS and ultraviolet UV may be applied. A process of loading the frame-integrated masks 100 and 200 into another chamber (not shown) and then removing only the separator insulating portion 23 by applying atmospheric pressure plasma or vacuum plasma PS or ultraviolet rays UV may be performed.

As described above, the present invention can allow the first mask pattern P1 to be formed at the maximum depth while keeping the bank at the thinnest thickness, and thus has an effect of enabling more precise control of the size and position when the mask pattern P is finally formed. Further, by using the mask support template including the mask metal film 110/the separator insulating portion 23/the temporary bonding portion 55/the template 50, there is an effect that errors due to penetration/leakage of the etching liquid in the 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 to the embodiments, and various modifications and alterations can be made thereto by those skilled in the art without departing from the spirit of the present invention. The modifications and variations are to be considered within the purview of the invention and the appended claims.

Claims

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 side of the mask metal film by wet etching;

(c) Forming a second insulating portion at least in the first mask pattern located at a vertically lower portion of the first insulating portion;

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

in the step (a), an auxiliary insulating portion having a width smaller than that of the first insulating portion is further formed between the first insulating portion patterns, and in the wet etching in the step (b), undercut due to etching occurs between the first insulating portion and the auxiliary insulating portion, and the first mask pattern is formed by the combination of the undercut,

The wet etching of step (b) and the wet etching of step (d) are performed on the same side of the mask metal film.

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 parts is 26 μm to 34 μm and the width of the auxiliary insulating part 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 parts after the step (b) is at least less than 4 μm and exceeds 0.

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

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

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

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

5. The method of manufacturing a mask according to claim 1, wherein after the step (d), the thickness of the first mask pattern is greater than the 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.

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

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

(a) A step of adhering a mask metal film to an upper face of the template;

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

step (b) comprises:

(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) Forming a second insulating portion at least in the first mask pattern located at a vertically lower portion of the first insulating portion;

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

in the step (b 1), an auxiliary insulating portion having a width smaller than that of the first insulating portion is further formed between the first insulating portion patterns, and in the wet etching in the step (b 2), undercut due to etching occurs between the first insulating portion and the auxiliary insulating portion, and the first mask pattern is formed by the combination of the undercut,

The wet etching of step (b 2) and the wet etching of step (b 4) are performed on the same side of the mask metal film.

8. The method of manufacturing a mask support template according to claim 7, wherein in the step (a), the mask metal film is adhered to the upper face of the template by sandwiching the separator insulating portion and the temporary adhesion portion.

9. The method of manufacturing a mask support template according to claim 7, wherein the spacer insulating portion 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 adhering a mask metal film to an upper face of the template;

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

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

step (b) comprises: