CN112740436A

CN112740436A - Method for manufacturing mask, method for manufacturing mask-supporting template, and method for manufacturing frame-integrated mask

Info

Publication number: CN112740436A
Application number: CN201980062036.3A
Authority: CN
Inventors: 李炳一; 张泽龙; 李裕进
Original assignee: Wuluomao Materials Co ltd
Current assignee: Wuluomao Materials Co ltd
Priority date: 2018-10-22
Filing date: 2019-10-15
Publication date: 2021-04-30
Also published as: KR102138801B1; TW202032833A; KR102236541B1; KR20200045451A; KR20200045386A

Abstract

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. A method of manufacturing a mask according to the present invention is a method of manufacturing a mask for forming an OLED pixel, the method including the steps of: (a) preparing a mask metal film (110); and (b) forming a mask pattern (P) on one surface of the mask metal film (110) by laser patterning (LE).

Description

Method for manufacturing mask, method for manufacturing mask-supporting template, and method for manufacturing frame-integrated mask

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. And more particularly, to a method of manufacturing a mask, a method of manufacturing a mask supporting template, and a method of manufacturing a frame-integrated mask, which can accurately form a mask pattern of a mask, can stably support and move the mask without deformation, can improve adhesion between the mask and a frame when the mask is integrated with the frame, and can make alignment (align) between the masks accurate.

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 at a desired position.

In the existing OLED manufacturing process, after a mask is manufactured in a bar shape, a plate shape, or the like, the mask is solder-fixed to an OLED pixel deposition frame and used. One mask may have a plurality of cells corresponding to one display. In addition, in order to manufacture a large-area OLED, a plurality of masks may be fixed to an OLED pixel deposition frame, and each mask is stretched to be flat in the process of being fixed to the frame. Adjusting the tensile force to flatten the entire portion of the mask is a very difficult task. In particular, in order to align a mask pattern having a size of only several μm to several tens μm while flattening all the cells, it is necessary to finely adjust the tensile force applied to each side of the mask and to confirm the height operation requirement of the alignment state in real time.

However, in the process of fixing a plurality of masks to one frame, there is a problem that alignment between the masks and between the mask units is not good. In addition, in the process of welding and fixing the mask to the frame, the mask film has a problem that the mask is sagged or distorted due to a load because the thickness of the mask film is too thin and the area of the mask film is large; a problem of misalignment of the mask unit due to wrinkles, burrs (burr), etc. generated at the welded portion during the welding process, etc.

In the ultra-high definition OLED, the conventional QHD image quality is 500-600PPI (pixel per inch), the pixel size reaches about 30-50 μm, and the 4K UHD and 8K UHD high definition have higher resolution of-860 PPI and-1600 PPI. In this way, in consideration of the pixel size of the ultra-high-definition OLED, it is necessary to reduce the alignment error between the units to about several μm, and exceeding this error causes product defects, so the yield may be extremely low. Therefore, it is necessary to develop a technique capable of preventing the sagging or distortion or the like of the mask and making the 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 of manufacturing a mask and a method of manufacturing a mask supporting template, in which a mask metal film can be patterned by a simple process when the mask is manufactured, and fine patterning can be performed.

Another object of the present invention is to provide a method for manufacturing a mask supporting template, which can stably support and move a mask without deforming the mask.

Further, an object of the present invention is to provide a method of manufacturing a mask supporting template capable of improving adhesion between a mask and a frame when the mask is attached to the frame.

Another object of the present invention is to provide a method for manufacturing a mask supporting template that can be repeatedly used after attaching a mask to a frame.

Another object of the present invention is to provide a method for manufacturing a frame-integrated mask, in which a mask and a frame can be integrally configured.

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

Another object of the present invention is to provide a method for manufacturing a frame-integrated mask, which can significantly reduce the manufacturing time and improve the yield.

Technical scheme

The above object of the present invention is achieved by a method of manufacturing a mask for forming an OLED pixel, wherein the method comprises the steps of: (a) preparing a mask metal film; and (b) forming a mask pattern on one surface of the mask metal film by laser patterning.

In step (b), the laser may have a pulse width of any one of nanosecond, femtosecond and picosecond.

In the step (b), the laser beam having a wide focal range is irradiated onto the upper portion of the mask metal film with reference to the thickness direction of the mask metal film, and the laser beam having a wide focal range is irradiated onto the upper portion of the mask metal film, and the laser beam having a narrow focal range is irradiated onto the lower portion of the mask metal film, thereby performing laser patterning.

In the step (b), after etching is performed to such an extent that the etching does not penetrate the mask metal film with reference to the thickness direction of the mask metal film, a mask pattern is formed by laser patterning to such an extent that the etching penetrates the mask metal film.

Further, the above object of the present invention is achieved by a method of manufacturing a mask supporting template for supporting a mask for OLED pixel formation and making the mask correspond to a frame, wherein the method comprises the steps of: (a) preparing a mask metal film; (b) bonding a mask metal film to a template having a temporary bonding portion formed on one surface thereof; and (c) manufacturing a mask by forming a mask pattern on one side of the mask metal film by laser patterning.

In step (c), the laser may have a pulse width of any one of nanosecond, femtosecond and picosecond.

In the step (c), the laser patterning is performed by irradiating the mask metal film with the laser beam having a wide focal range at an upper portion thereof and irradiating the mask metal film with the laser beam having a narrow focal range at a lower portion thereof, with respect to the thickness direction of the mask metal film.

In the step (c), after etching is performed to such an extent that the mask metal film is not penetrated with respect to the thickness direction of the mask metal film, a mask pattern is formed by laser patterning to such an extent that the mask metal film is penetrated.

The temporary bonding portion may be an adhesive or an adhesive sheet that can be separated by heating, an adhesive or an adhesive sheet that can be separated by irradiation with ultraviolet rays.

Further, the above object of the present invention is achieved by a method of manufacturing a frame-integrated type mask integrally formed of at least one mask and a frame for supporting the mask, wherein the method comprises the steps of: (a) loading the template manufactured by the manufacturing method of claim 5 onto a frame having at least one mask unit region so that the mask corresponds to the mask unit region of the frame; and (b) attaching the mask to the frame.

Effects of the invention

According to the present invention as described above, there is an effect that a mask metal film can be patterned through a simple process and fine patterning can be performed when a mask is manufactured.

In addition, the present invention has an effect that the mask is stably supported and moved without being deformed.

In addition, the present invention has an effect of improving adhesion of the mask to the frame when the mask is attached to the frame.

In addition, the present invention has an effect that the mask can be repeatedly used after being attached to the frame.

In addition, the present invention has an effect that the mask and the frame can be formed into an integral structure.

In addition, the present invention has an effect of preventing deformation such as sagging or twisting of the mask and accurately performing alignment.

In addition, the present invention has the effect of significantly shortening the production time and significantly improving the yield.

Drawings

Fig. 1 is a schematic view showing a conventional OLED pixel deposition mask.

Fig. 2 is a schematic view showing an existing process of attaching a mask to a frame.

Fig. 3 is a schematic view showing an alignment error between cells occurring in a conventional mask stretching process.

Fig. 4 is a front view and a side sectional view showing a frame-integrated mask according to an embodiment of the present invention.

Fig. 5 is a front view and a side sectional view showing a frame of an embodiment of the present invention.

Fig. 6 is a schematic view showing a frame manufacturing process of an embodiment of the present invention.

Fig. 7 is a schematic view showing a frame manufacturing process of another embodiment of the present invention.

Fig. 8 is a schematic view illustrating a conventional mask for forming a high-resolution OLED.

Fig. 9 is a schematic view showing a mask according to an embodiment of the present invention.

Fig. 10 is a schematic view showing a process of manufacturing a mask metal film by rolling (rolling) according to an embodiment of the present invention.

Fig. 11 is a schematic view showing a process of manufacturing a mask metal film by electroforming according to another embodiment of the present invention.

Fig. 12 to 13 are schematic views illustrating a process of forming a mask by bonding a mask metal film to a stencil to manufacture a mask supporting stencil according to an embodiment of the present invention.

Fig. 14 is a schematic view showing an enlarged cross section of a temporary bonding portion according to an embodiment of the present invention.

Fig. 15 is a schematic view showing a process of loading a mask support template on a frame according to an embodiment of the present invention.

Fig. 16 is a schematic view showing a state in which a mask is mounted on a frame so as to correspond to a cell region of the frame according to an embodiment of the present invention.

Fig. 17 is a schematic view illustrating a process of separating a mask from a stencil after attaching the mask to a frame according to an embodiment of the present invention.

Fig. 18 is a schematic view showing a state in which a mask is attached to a frame according to an embodiment of the present invention.

Fig. 19 is a schematic view illustrating an OLED pixel deposition apparatus using a frame-integrated mask according to an embodiment of the present invention.

[ reference numerals ]

50: stencil (template)

51: laser passing hole

55: temporary bonding part

70: lower support

100: mask and method for manufacturing the same

110: mask film

200: frame structure

210: edge frame section

220: mask unit sheet part

221: edge sheet part

223: first grid sheet part

225: second grid sheet part

1000: OLED pixel deposition device

C: cell and mask cell

CM: chemical treatment

CR: mask unit region

DM: dummy part and mask dummy part

ET: heating of

L: laser

LE: laser patterning

R: hollow region of edge frame part

P: mask pattern

US: applying ultrasonic waves

UV: application of ultraviolet light

W: welding of

WB: welding bead

Detailed Description

The following detailed description of the invention refers to the accompanying drawings, which illustrate specific embodiments by way of example, 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. The various embodiments of the invention, although different from one another, are not necessarily mutually exclusive. For example, particular shapes, structures and characteristics described herein may be associated with one embodiment and may be implemented in other embodiments without departing from the spirit and scope of the present invention. The position and arrangement of the individual components in the respective disclosed embodiments can be changed without departing from the spirit and scope of the present 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, appropriately interpreted, along with the full range of equivalents to which the claims are entitled. Like reference numerals in the drawings denote the same or similar functions in many respects, and the length, area, thickness, and shape thereof may be exaggerated for convenience.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings so that those skilled in the art can easily carry out the present invention.

Fig. 1 is a schematic view showing a conventional OLED pixel deposition mask 10.

Referring to fig. 1, a conventional mask 10 may be manufactured in a stripe Type (Stick-Type) or a Plate Type (Plate-Type). The mask 10 shown in fig. 1 (a) is used as a bar mask, and both sides of the bar may be solder-fixed to an OLED pixel deposition frame. The mask 100 shown in fig. 1 (b) is used as a plate mask in a large-area pixel formation process.

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. When the cell C is enlarged, a plurality of pixel patterns P corresponding to R, G, B are displayed. As an example, the pixel pattern P is formed in the cell C so as to have a resolution of 70 × 140. That is, a large number of pixel patterns P are formed to be aggregated to constitute one cell C, and a plurality of cells C may be formed on the mask 10.

Fig. 2 is a schematic view showing a conventional process of bonding the mask 10 to the frame 20. Fig. 3 is a schematic view showing an alignment error between cells occurring in the process of stretching the conventional F1-F2 mask 10. The stripe mask 10 having 6 cells C (C1-C6) in fig. 1 (a) will be described as an example.

Referring to fig. 2 (a), first, the stripe mask 10 should be spread flat. A stretching force F1 to F2 is applied in the long axis direction of the strip mask 10, and the strip mask 10 is unfolded as it is stretched. In this state, the strip masks 10 are loaded on the frame 20 having a square frame shape. The cells C1-C6 of the strip mask 10 will be located in the blank area portions inside the frame 20. The size of the frame 20 may be sufficient to allow the cells C1-C6 of one strip 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 strip masks 10 to be located in a blank area inside the frame.

Referring to fig. 2 (b), after alignment is performed while fine-adjusting the tensile forces F1 to F2 applied to the sides of the strip masks 10, a portion of the sides of the W strip masks 10 are welded, and the strip masks 10 and the frame 20 are connected. Fig. 2 (c) shows a side cross-section of the bar mask 10 and the frame connected to each other.

Referring to fig. 3, although the tensile forces F1 through F2 applied to the sides of the strip mask 10 are finely adjusted, there occurs a problem that the mask units C1 through C3 are not aligned well with each other. For example, the distances D1-D1 ", D2-D2" between the patterns P of the cells C1-C3 are different from each other, or the patterns P are skewed. Since the stripe mask 10 has a large area including a plurality of (as an example, 6) cells C1-C6 and a very thin thickness of several tens of μm, it is easily sagged or distorted by a load. 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.

Therefore, a slight error in the tensile forces F1 to F2 may cause an error in the degree of stretching or unfolding of the cells C1 to C3 of the strip mask 10, thereby causing differences in the distances D1 to D1 ", D2 to D2" between the mask patterns P. Although it is very difficult to perfectly align to make the error 0, the alignment error is preferably not more than 3 μm in order to avoid bad influence of the mask pattern P having a size of several μm to several tens μm on the pixel process of the ultra high definition OLED. The alignment error between such adjacent cells is referred to as Pixel Position Accuracy (PPA).

In addition, it is very difficult to precisely align the states of alignment between the bar masks 10 and between the cells C1-C6 of the bar masks 10 while respectively connecting approximately 6 to 20 bar masks 10 to one frame 20, and it only increases the process time based on the alignment, which becomes an important reason for lowering productivity.

On the other hand, after the strip masks 10 are attached and fixed to the frame 20, the tensile forces F1 to F2 applied to the strip masks 10 can act in reverse on the frame 20. That is, after the bar mask 10, which is tensed and stretched by the stretching forces F1 to F2, is attached to the frame 20, a tension (tension) can be applied to the frame 20. Normally, the tension does not largely affect the frame 20 when it is not large, but when the frame 20 is downsized and has low strength, the frame 20 is slightly deformed by the tension. Thus, a problem of breaking the alignment state among the plurality of cells C1-C6 may occur.

In view of this, the present invention provides a frame 200 and a frame-integrated mask, which can form the mask 100 and the frame 200 into an integrated structure. Not only can the mask 100 integrally formed with the frame 200 be prevented from being deformed such as drooping or twisting, but also can be accurately aligned with the frame 200. When the mask 100 is attached to the frame 200, any tensile force is not applied to the mask 100, and thus, after the mask 100 is attached to the frame 200, no tensile force causing deformation is applied to the frame 200. Also, the manufacturing time for integrally connecting the mask 100 to the frame 200 can be significantly shortened, and the yield can be significantly improved.

Fig. 4 is a front view (fig. 4 (a)) and a side sectional view (fig. 4 (b)) showing a frame-integrated mask according to an embodiment of the present invention, and fig. 5 is a front view (fig. 5 (a)) and a side sectional view (fig. 5 (b)) showing a frame according to an embodiment of the present invention.

Referring to fig. 4 and 5, 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. Hereinafter, for convenience of explanation, the mask 100 having a square shape is exemplified, but the mask 100 may have a bar mask shape having protrusions for clamping at 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 have a coefficient of thermal expansion of about 1.0 x 10^-6Invar (invar) at/° C or about 1.0X 10^-7Super invar (super invar) material at/° c. Since the Mask 100 of such a material has a very low thermal expansion coefficient and the pattern shape of the Mask is less likely to be deformed by thermal energy, it can be used as an fmm (fine Metal Mask) or a Shadow Mask (Shadow Mask) in manufacturing a high-resolution OLED. In addition, in consideration of recent development of a technique for performing a pixel deposition process in a range in which a temperature variation value is not large, the mask 100 may be made of nickel (Ni), nickel-cobalt (Ni-Co), or the like having a slightly larger thermal expansion coefficient. The mask 100 may use a sheet metal (sheet) generated by a rolling process or electroforming. This will be described in detail with reference to fig. 9 and 10.

The frame 200 is formed in a form capable of attaching a plurality of masks 100. The frame 200 may include a plurality of corners formed along a first direction (e.g., a lateral direction), a second direction (e.g., a vertical direction) including the outermost peripheral edge. Such a plurality of corners may divide an area for attaching the mask 100 on the frame 200.

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. That is, the edge frame portion 210 may include a hollow region R. The frame 200 may be formed of a metal material such as invar, super-invar, aluminum, titanium, etc., and the frame 200 is preferably formed of an invar, super-invar, nickel-cobalt, etc., having the same thermal expansion coefficient as the mask in consideration of thermal deformation, which are applied to the edge frame portion 210 and the mask unit sheet portion 220, which are components of the frame 200.

In addition, the frame 200 has a plurality of mask unit regions CR, and may include a mask unit sheet part 220 connected to the edge frame part 210. The mask unit piece portion 220 may be formed by rolling or other film forming processes such as electroforming, like the mask 100. The mask unit sheet portion 220 may be connected to the edge frame portion 210 by forming a plurality of mask unit regions CR on a planar sheet (sheet) by laser scribing, etching, or the like. Alternatively, the mask unit sheet portion 220 may be formed by laser scribing, etching, or the like after a planar sheet is connected to the edge frame portion 210. In this specification, a case where the mask unit sheet portion 220 is first formed with the plurality of mask unit regions CR and then connected to the edge frame portion 210 will be mainly described.

The mask unit sheet portion 220 may include an edge sheet portion 221 and at least one of 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 integrated with each other.

The edge sheet portion 221 may be substantially connected to the edge frame portion 210. Therefore, the edge sheet portion 221 may have a substantially rectangular, square box shape corresponding to the edge frame portion 210.

In addition, the first grid sheet part 223 may be formed to extend along the first direction (lateral direction). The first grid sheet portion 223 is formed in a straight line shape, and both ends thereof may be connected to the edge sheet portion 221. When the mask unit sheet portion 220 includes a plurality of first grid sheet portions 223, each of the first grid sheet portions 223 preferably has the same pitch.

In addition, the second grid sheet portion 225 may be formed to extend in the second direction (vertical direction), and the second grid sheet portion 225 is formed in a straight line state, and both ends thereof may be connected to the edge sheet portion 221. The first and second

grid sheet portions

223, 225 may cross each other perpendicularly. When the mask unit sheet portion 220 includes a plurality of second grid sheet portions 225, each of the second grid sheet portions 225 preferably has the same pitch.

On the other hand, the pitch between the first grid sheet portions 223 and the pitch between the second grid sheet portions 225 may be the same or different according to the size of the mask unit C.

The first and second

grid sheet portions

223 and 225 have a thin thickness in the form of a thin film, but the cross-sectional shape perpendicular to the longitudinal direction may be a rectangular shape, a trapezoidal quadrangular shape, a triangular shape, or the like, and the sides and corners may be rounded. The cross-sectional shape may be adjusted during laser scribing, etching, etc.

The thickness of the edge frame portion 210 may be greater than the thickness of the mask die sheet portion 220. Since the edge frame portion 210 takes charge of the overall rigidity of the frame 200, it can be formed to a thickness of several mm to several cm.

With the mask unit sheet portion 220, a process of manufacturing a thick sheet is substantially difficult, and if it is too thick, there is a possibility that the organic matter source 600[ refer to fig. 19] blocks a path through the mask 100 in the OLED pixel deposition process. In contrast, if it is too thin, it may be difficult to ensure sufficient rigidity to support the mask 100. Therefore, the mask die section 220 is preferably thinner than the thickness of the edge frame section 210, but thicker than the mask 100. The thickness of the mask die portion 220 may be about 0.1mm to 1 mm. Also, 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-CR56) 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. From another perspective, the mask unit region CR may refer to a blank region of the hollow region R of the edge frame portion 210 except for regions occupied by the edge sheet portion 221, the first grid sheet portion 223, and the second grid sheet portion 225.

As the cells C of the mask 100 correspond to the mask cell regions CR, they can be substantially used as channels for depositing pixels of the OLED through the mask pattern P. As described above, one mask unit C corresponds to one display of a smartphone or the like. A mask pattern P for constituting one cell C may be formed in one mask 100. Alternatively, one mask 100 has a plurality of cells C and each cell C may correspond to each cell region CR of the frame 200, but in order to precisely align the mask 100, it is necessary to avoid using a large-area mask 100, and the mask 100 preferably has a small area of one cell C. Alternatively, one mask 100 having a plurality of cells C may correspond to one cell region CR of the frame 200. At this time, in order to precisely align, the mask 100 corresponding to the cell having about 2-3 few cells C may be considered.

The mask 200 has a plurality of mask cell regions CR, and the masks 100 may be attached so that the mask cells C correspond to the mask cell regions CR, respectively. Each mask 100 may include a mask cell C in which a plurality of mask patterns P are formed, and a dummy portion (corresponding to a portion of the mask film 110 other than the cell C) around the mask cell C. The dummy portion 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 mask unit C corresponds to the mask unit region CR of the frame 200, and a part or all 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.

On the other hand, according to another embodiment, the frame is not manufactured in such a manner that the mask unit sheet portions 220 are attached to the edge frame portion 210, but a frame in which a grid frame (corresponding to the grid sheet portions 223, 225) integrated with the edge frame portion 210 is directly formed at the hollow region R portion of the edge frame portion 210 may be used. The frame of this form further includes at least one mask cell region CR, and the mask 100 may be made to correspond to the mask cell region CR to manufacture a frame-integrated mask.

Next, a process of manufacturing the frame-integrated mask will be described.

First, the frame 200 described in fig. 4 and 5 may be provided. Fig. 6 is a schematic view showing a manufacturing process of the frame 200 according to an embodiment of the present invention.

Referring to fig. 6 (a), an edge frame portion 210 is provided. The edge frame portion 210 may be a box shape including a hollow region R.

Next, referring to fig. 6 (b), the mask unit sheet portion 220 is manufactured. The mask unit sheet portion 220 is manufactured by manufacturing a planar sheet by rolling, electroforming, or another film forming process, and then removing the mask unit region CR portion by laser scribing, etching, or the like. In this specification, the formation of the 6 × 5 mask cell region CR (CR11-CR56) will be described as an example. There may be 5 first

grid sheet portions

223 and 4 second grid sheet portions 225.

Then, the mask die section 220 may be corresponded to the edge frame section 210. In the corresponding process, the edge sheet part 221 may be corresponded to the edge frame part 210 in a state where all side portions of the mask cell sheet part 220 are stretched F1-F4 to spread the mask cell sheet part 220 flat. The mask die portion 220 can be stretched by sandwiching it at a plurality of points (1 to 3 points as an example of fig. 6 (b)) on one side. On the other hand, the F1 and F2 mask cell sheet portions 220 may be stretched in some side direction, not all the side portions.

Then, if the mask die portions 220 correspond to the edge frame portions 210, the edge die portions 221 of the mask die portions 220 may be attached in a welding W manner. Preferably, all sides of W are welded so that the mask die section 220 is firmly attached to the edge frame section 210. The welding W should be performed close to the corner side of the frame portion 210 to the maximum extent so that the tilting space between the edge frame portion 210 and the mask unit sheet portion 220 can be minimized and the adhesion can be improved. The welding W portion may be generated in a line (line) or spot (spot) shape, have the same material as the mask unit sheet portion 220, and may become a medium for integrally connecting the edge frame portion 210 and the mask unit sheet portion 220.

Fig. 7 is a schematic view showing a frame manufacturing process of another embodiment of the present invention. The embodiment of fig. 6 first manufactures the mask unit sheet portions 220 having the mask unit regions CR and then attaches to the edge frame portions 210, while the embodiment of fig. 7 attaches a planar sheet to the edge frame portions 210 and then forms the mask unit region CR portions.

First, as shown in fig. 6 (a), an edge frame portion 210 including a hollow region R is provided.

Then, referring to fig. 7 (a), a planar sheet (a planar mask unit sheet portion 220') may be corresponded to the edge frame portion 210. The mask unit sheet portion 220' is in a planar state in which the mask unit region CR is not yet formed. In a corresponding process, the mask unit sheet portion 220 ' may be corresponded to the edge frame portion 210 in a state where all side portions of the mask unit sheet portion 220 ' are stretched and the mask unit sheet portion 220 ' is flatly stretched, F1-F4. The unit sheet portion 220' may be sandwiched and stretched at a plurality of points (1 to 3 points as an example of fig. 7 (a)) at one side portion. On the other hand, the F1, F2 mask unit sheet portions 220' may be stretched not all along the side portions but along a part of the side portions.

Then, if the mask unit sheet portion 220 'corresponds to the edge frame portion 210, the edge portion of the mask unit sheet portion 220' may be attached in a welding W manner. Preferably, all sides of W are welded so that the mask unit sheet portion 220' is firmly attached to the edge frame portion 220. The welding W should be performed close to the corner side of the edge frame portion 210 to the maximum extent so as to minimize the turn-up space between the edge frame portion 210 and the mask unit sheet portion 220' and improve the adhesion. The welding W portion may be generated in a line (line) or spot (spot) shape, have the same material as the mask unit sheet portion 220 ', and may become a medium for integrally connecting the edge frame portion 210 and the mask unit sheet portion 220'.

Then, referring to fig. 7 (b), a mask unit region CR is formed in the planar sheet (the planar mask unit sheet portion 220'). The sheet of the mask unit region CR portion is removed by laser scribing, etching, or the like, so that the mask unit region CR can be formed. In this specification, the formation of the 6 × 5 mask cell region CR (CR11-CR56) will be described as an example. After the mask unit region CR is formed, the mask unit sheet portion 220 may be configured in which a portion welded W to the edge frame portion 210 becomes an edge sheet portion 221, and the mask unit sheet portion 220 has 5 first

grid sheet portions

223 and 4 second grid sheet portions 225.

In order to realize a high-resolution OLED, the size of the pattern is gradually reduced, and the thickness of the mask metal film used therefor is also required to be thin. As shown in fig. 8 (a), if it is desired to realize the OLED pixel 6 with high resolution, it is necessary to reduce the pixel interval and the pixel size and the like (PD- > PD ') in the mask 10'. Furthermore, to prevent shadow effects from causing the OLED pixels 6 to deposit unevenly, the mask 10' needs to be patterned obliquely 14. However, in the process of forming 14 patterns obliquely in the thick mask 10 'having the thickness T1 of about 30-50 μm, since it is difficult to perform patterning 13 matching the fine pixel interval PD' and the pixel size, it becomes a factor of lowering the yield in the process. In other words, in order to form the pattern 14 obliquely with a fine pixel pitch PD ', a mask 10' having a small thickness should be used.

Specifically, in order to realize a high resolution of UHD level, fine patterning can be performed only by using a thin mask 10' having a thickness T2 of 20 μm or less, as shown in fig. 8 (b). Furthermore, to achieve ultra high resolution above UHD, it is contemplated to use a thinner mask 10' having a thickness T2 of 10 μm.

Fig. 9 is a schematic view showing a mask 100 according to an embodiment of the present 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. As described above, the mask 100 may be manufactured using a metal sheet produced by a rolling process, electroforming, or the like, and as described above, one cell C may be formed in the mask 100. The dummy portion DM corresponds to a portion of the mask film 110[ mask metal film 110] other than the cell C, and may include only the mask film 110, or include the mask film 110 formed with a predetermined dummy portion pattern similar to the shape of 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 die portion 220 ].

The width of the mask pattern P may be less than 40 μm and the thickness of the mask 100 may be about 5-20 μm. Since the frame 200 has a plurality of mask cell regions CR (CR11-CR56), it may also have a plurality of masks 100, the masks 100 including mask cells C (C11-C56) corresponding to each mask cell region CR (CR11-CR 56).

Since the one surface 101 of the mask 100 is a surface that contacts and adheres to the frame 200, a flat surface is preferable. One side 101 may be mirrored while being planarized by a planarization process described below. The other side 102 of the mask 100 may be opposite to a side of the template 50 described below.

Next, a series of processes of manufacturing the frame-integrated mask by supporting the mask metal film 110' on the template 50 after manufacturing to manufacture the mask 100 and attaching the mask to the frame 200 after loading the template 50 supporting the mask 100 to the frame 200 will be described.

Fig. 10 is a schematic view showing a process of manufacturing a mask metal film by rolling (rolling) according to an embodiment of the present invention. Fig. 11 is a schematic view showing a process of manufacturing a mask metal film by electroforming according to another embodiment of the present invention.

First, the mask metal film 110 may be prepared. As an example, the mask metal film 110 may be prepared by a rolling process.

Referring to fig. 10 (a), a metal sheet generated by a rolling process may be used as the mask metal film 110'. The metal sheet manufactured by the rolling process may have a thickness of several tens to several hundreds of μm according to the manufacturing process. As described in fig. 8, in order to obtain a high resolution of UHD level, fine patterning can be performed only by using a thin mask metal film 110 having a thickness of 20 μm or less, and in order to obtain an ultra high resolution of UHD or more, it is necessary to use a thin mask metal film 110 having a thickness of about 10 μm. However, the thickness of the mask metal film 110' generated by the rolling process is about 25 to 500 μm, and thus it is necessary to further thin the thickness.

Accordingly, a process of planarizing PS one side of the mask metal film 110' may be further performed. Here, the planarization PS refers to a process of thinning the mask metal film 110 'by partially removing the upper portion thereof while forming a mirror surface on one surface (upper surface) of the mask metal film 110'. The planarization PS can be carried out by a CMP (Chemical Mechanical Polishing) method, and any known CMP method can be used without limitation. In addition, the thickness of the mask metal film 110' may be thinned using a chemical wet etching (chemical wet etching) or dry etching (dry etching) method. In addition, there is no particular limitation as long as the planarization process can reduce the thickness of the mask metal film 110'.

In performing the planarization PS, as an example, the surface roughness Ra of the upper face of the mask metal film 110' may be controlled in the CMP process. Preferably, a mirroring for further reducing the surface roughness may be performed. Or, as another example, the planarization PS may be performed by a chemical wet etching or dry etching process, followed by an additional polishing process such as CMP to reduce the surface roughness Ra.

Thus, the mask metal film 110' can be manufactured to have a thickness of about 50 μm or less. Thus, the thickness of the mask metal film 110 is preferably formed to be about 2 μm to 50 μm, and more preferably, the thickness may be about 5 μm to 20 μm. However, it is not necessarily limited thereto.

Referring to fig. 10 (b), as in fig. 10 (a), the mask metal film 110 may be manufactured by reducing the thickness of the mask metal film 110' manufactured by the rolling process. Only, the mask metal film 110' is bonded to the template 50 described later with the temporary bonding portion 55 interposed therebetween, and the planarization PS process is performed in this state, whereby the thickness can be reduced.

As another example, the mask metal film 110 may be prepared by electroforming.

Referring to fig. 11 (a), a conductive base material 21 is prepared. In order to be able to perform electroforming (electroforming), the substrate 21 of the master may be a conductive material. The master plate can be used as a cathode body (cathode) electrode in electroforming.

As a conductive material, a metal oxide is formed on a metal surface, impurities flow in a metal production process, inclusions or Grain boundaries (Grain Boundary) are present on a polycrystalline silicon substrate, the conductive polymer substrate has a high possibility of containing impurities, and is weak in strength, acid resistance, and the like. Elements that prevent an electric field from being uniformly formed on the surface of the mother substrate (or cathode body), such as metal oxides, impurities, inclusions, grain boundaries, and the like, will be referred to as "defects" (defects) hereinafter. Due to such defects (defects), a uniform electric field cannot be applied to the cathode body of the above-described material, and thus a part of the plated film 110 (mask metal film 110) is formed unevenly.

In the case of realizing a pixel of ultra high quality at a UHD level or higher, unevenness of a plating film and a plating film pattern (mask pattern P) adversely affects formation of the pixel. For example, the current QHD image quality is 500 PPI and 600PPI, the pixel size reaches about 30-50 μm, and the high image quality of 4K UHD and 8K UHD has higher resolution of-860 PPI and-1600 PPI than the former. Microdisplays that are directly suitable for use on VR machines or for use inserted into VR machines target ultra-high picture quality on the order of about 2000PPI or more, with pixels of about 5-10 μm in size. The pattern width of FMM, a shadow mask suitable for use therein may be formed to several μm to several tens of μm, preferably less than 30 μm, and thus even a defect of several μm size occupies a large specific gravity in the pattern of the mask. In addition, in order to remove defects of the material in the cathode body, an additional process for removing metal oxide, impurities, and the like may be performed, and in this process, other defects such as etching of the cathode body material may be additionally generated.

Therefore, the present invention can use a mother substrate (or cathode body) of a single crystal material. Particularly preferred is a single crystal silicon material. A mother substrate of single crystal silicon material may be subjected to 10¹⁹/cm³The above is doped at a high concentration so as to have conductivity. The doping may be performed on the entire motherboard or only on a surface portion of the motherboard.

Further, as the single crystal material, a metal such as Ti, Cu, or Ag; semiconductors such as GaN, SiC, GaAs, GaP, AlN, InN, InP, and Ge; carbon-based materials such as graphite (graphite) and graphene (graphene); comprising CH₃NH₃PbCl₃、CH₃NH₃PbBr₃、CH₃NH₃PbI₃、SrTiO₃And single crystal ceramics for superconducting conductors such as perovskite (perovskite) structures; single crystal superalloys for aircraft components and the like. The metal or carbon-based material is basically a conductive material. For semiconductor materials, to be conductive, 10 can be implemented¹⁹/cm³The above high concentration doping. Other materials may be made conductive by performing doping or forming oxygen vacancies (oxygen vacancies), or the like. The doping may be performed on the entire body of the mother plate or only on a surface portion of the mother plate.

The single crystal material has no defects, and thus has an advantage that a uniform electric field can be formed over the entire surface during electroforming, thereby enabling the formation of a uniform plating film 110. The frame-integrated

mask

100, 200 manufactured by the uniform plating film may further improve the image quality level of the OLED pixel. In addition, since an additional process for removing or eliminating the defect is not required, there is an advantage that the process cost can be reduced and the productivity can be improved.

Referring again to fig. 10 (a), the conductive substrate 21 is then used as a mother substrate [ Cathode Body (Cathode Body) ] and anode bodies (not shown) are arranged at a distance so that the plating film 110[ or the mask metal film 110] can be formed on the conductive substrate 21 by electroforming. The plating film 110 may be formed on the exposed upper and side surfaces of the conductive substrate 21, the conductive substrate 21 being disposed opposite to the anode body and being capable of applying an electric field. The plating film 110 may be formed not only on the side surface of the conductive substrate 21 but also on a part of the lower surface of the conductive substrate 21.

Then, an edge portion of the plated film 110 is cut by laser or a photoresist layer is formed on the upper portion of the plated film 110 and only the portion of the plated film 110 exposed by D is etched and removed. As shown in fig. 10 (b), the plating film 110 can be separated from the conductive substrate 21.

Further, the heat treatment H may be performed before the plated film 110 is separated from the conductive base material 21. The present invention is characterized in that the thermal treatment H is performed before the plating film 110 is separated from the conductive base material 21[ or the master plate or the cathode body ] in order to reduce the thermal expansion coefficient of the mask 100 and prevent the mask 100 and the mask pattern P from being deformed by heat. The heat treatment may be performed at a temperature of 300 ℃ to 800 ℃.

Generally, the coefficient of thermal expansion of an invar alloy sheet produced by electroforming is higher than that of an invar alloy sheet produced by rolling. Therefore, the thermal expansion coefficient can be reduced by heat-treating the invar alloy thin plate, but the invar alloy thin plate is peeled, deformed, and the like during the heat treatment. This is because the invar alloy sheet is heat-treated alone or the invar alloy sheet temporarily attached to only the upper surface of the conductive base material 21 is heat-treated. However, in the present invention, the plating film 110 is formed not only on the upper surface of the conductive base material 21 but also on the side surface and the lower surface, and therefore, peeling, deformation, and the like do not occur even if the heat treatment H is performed. In other words, since the heat treatment is performed in a state where the conductive base material 21 and the plating film 110 are tightly adhered, the present invention has an advantage that peeling, deformation, and the like due to the heat treatment can be prevented and the heat treatment can be stably performed.

The thickness of the mask metal film 110 produced by the electroforming process may be thinner than that produced by the rolling process. Therefore, although the planarization PS process for reducing the thickness may be omitted, the surface characteristics and the thickness need to be controlled by the planarization PS process because the composition of the surface layer of the plated mask metal film 110' and the etching characteristics of the crystal structure and the microstructure are different.

Fig. 12 to 13 are schematic views illustrating a process of adhering a mask metal film 110 to a stencil 50 and forming a mask 100 to manufacture a mask supporting stencil according to an embodiment of the present invention.

Referring to fig. 12 (a), a template 50 may be provided. The mask 50 is a medium that moves in a state where the mask 100 is attached to and supported by one surface of the mask 50. One side of the template 50 is preferably flat in shape so as to be able to support and move the flat 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. The stencil 50 may be in the shape of a large flat plate having a size larger than that of the mask metal film 110 so that the mask metal film 110 is supported as a whole.

In order to facilitate visual observation (vision) or the like during the process of aligning and attaching the mask 100 to the frame 200, the template 50 is preferably made of a transparent material.Furthermore, if the material is transparent, the laser light can also be passed through. As the transparent material, glass (glass), silica (silica), heat-resistant glass, quartz (quartz), alumina (Al), can be used₂O₃) Borosilicate glass (borosilicate glass), zirconia (zirconia), and the like. As an example, the template 50 may use borosilicate glass having excellent heat resistance, chemical durability, mechanical strength, transparency, and the like

33 of a material. Furthermore, it is possible to provide a liquid crystal display device,

33 has a thermal expansion coefficient of about 3.3, which is not much different from that of the invar alloy mask metal film 110, and has an advantage of facilitating control of the mask metal film 110.

In addition, the surface of the template 50 that contacts the mask metal film 110 may be a mirror surface so that a gap (air gap) is not formed between the template 50 and the interface of the mask metal film 110[ or the mask 100 ]. Based on this, the surface roughness Ra of one surface of the template 50 may be 100nm or less. In order to realize the template 50 having the surface roughness Ra of 100nm or less, a wafer (wafer) may be used as the template 50. The surface roughness Ra of the wafer is about 10nm, and the product is more on the market, and the surface treatment process is well known, so it can be used as the template 50. Since the surface roughness Ra of the mask 50 is in the order of nm, the void AG is not present or is almost absent, and the solder ball WB is easily generated by laser welding, thereby having no influence on the alignment error of the mask pattern P.

The mask 50 may be formed with a laser passing hole 51 so that the laser L irradiated from an upper portion of the mask 50 reaches a welding portion (a region where welding is performed) of the mask 100. The laser passage holes 51 may be formed in the die plate 50 corresponding to the positions and the number of the welding portions. The soldering portions may be arranged in plural at predetermined intervals at the edge of the mask 100 or the dummy portion DM portion, and thus the laser passing holes 51 may also be formed in plural corresponding thereto and at predetermined intervals. As an example, since the soldering portions are arranged in plural at predetermined intervals at both sides (left/right sides) of the dummy portion DM portion of the mask 100, the laser passing holes 51 may also be formed in plural at predetermined intervals at both sides (left/right sides) of the template 50.

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

The template 50 may have a temporary bonding portion 55 formed on one surface thereof. The temporary bonding portion 55 temporarily bonds the mask 100[ or the mask metal film 110] to one surface of the stencil 50 and supports on the stencil 50 before attaching the mask 100 to the frame 200.

The temporary bonding portion 55 uses an adhesive or a bonding sheet (thermal release type) separable by heating, an adhesive or a bonding sheet (UV release type) separable by irradiating ultraviolet rays.

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 semiconductor wafer polishing step or the like, and the kind thereof is not particularly limited. The liquid wax mainly contains substances such as acrylic acid, vinyl acetate, nylon, and various polymers as resin components for controlling adhesion, impact resistance, and the like associated with a holding power, and a solvent. As an example, Acrylonitrile-butadiene rubber (ABR) may be used as the resin component of the temporary bonding portion 55, and SKYLIQUID ABR-4016 containing n-propanol may be used as the solvent component. The liquid wax may be formed on the temporary bonding portion 55 by spin coating.

The temporary bonding portion 55, which is liquid wax, has a decreased viscosity at a temperature higher than 85 c to 100 c and an increased viscosity at a temperature lower than 85 c, and a portion becomes hard like a solid, thereby fixedly bonding the mask metal film 110' to the stencil 50.

Then, referring to fig. 12 (b), the mask metal film 110' may be adhered to the stencil 50. After the liquid wax is heated to 85 ℃ or more and the mask metal film 110 'is brought into contact with the stencil 50, the mask metal film 110' and the stencil 50 are passed between rollers and bonded.

According to an embodiment, the stencil 50 is baked (baking) at a temperature of about 120 ℃ for 60 seconds, the solvent of the temporary bonding portion 55 is vaporized, and a lamination process of the mask metal film is directly performed. The lamination may be 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 ℃ and a lower roller of about 0 ℃. As a result, the mask metal film 110' can be contacted on the template 50 by interposing the temporary bonding portion 55.

Fig. 14 is a schematic view showing an enlarged cross section of the temporary bonding portion 55 according to an embodiment of the present invention. As still another example, the temporary bonding portion 55 may use a thermal release tape (thermal release tape). The thermal release tape is a core film 56 with a PET film or the like disposed in the middle, both sides of the core film 56 are disposed with thermal release adhesive layers (57 a, 57 b) that can be thermally released, and the peripheries of the

adhesive layers

57a, 57b may be disposed with release films/

release films

58a, 58 b. Among them, the peeling temperatures of the

adhesive layers

57a, 57b disposed on both sides of the core film 56 may be different from each other.

According to an embodiment, in a state where the release films/

release films

58a, 58b are removed, the lower face [ second adhesive layer 57b ] of the thermal release tape may be adhered to the stencil 50, and the upper face [ first adhesive layer 57a ] of the thermal release tape may be adhered to the mask metal film 110'. Since the first adhesive layer 57a and the second adhesive layer 57b are peeled at different temperatures, the mask 100 can be separated from the template 50 and the temporary bonding portion 55 by heating the first adhesive layer 57a when the template 50 is separated from the mask 100 in fig. 17 described later.

Next, referring to fig. 12 (b), one surface of the mask metal film 110' may be planarized PS. As described above, the thickness of the mask metal film 110 'made by the rolling process in fig. 10 can be thinned by the planarization PS process (110' - > 110). Furthermore, the mask metal film 110 produced by the electroforming process may be subjected to the planarization PS process to control the surface characteristics and thickness thereof.

Therefore, as shown in (c) of fig. 12, as the thickness of the mask metal film 110 'is reduced (110' - >110), the thickness of the mask metal film 110 may become about 5 μm to 20 μm.

Next, referring to fig. 13 (d), laser patterning LE may be performed on the upper portion of the mask metal film 110. The laser light may be irradiated on the upper or lower portion of the mask metal film 110 to transmit the laser light through the stencil 50. As a result of the laser patterning LE by the laser irradiation, a mask pattern P is formed on the mask metal film 110, and an alignment pattern, a dummy portion pattern, a wrinkle preventing pattern, and the like may be formed in addition to the mask pattern P.

Although the mask pattern P may have a reverse taper shape by laser patterning LE, it is not limited thereto. The laser patterning LE has an advantage in that the mask pattern P can be formed in a simple process according to the size and resolution. The laser may have a nanosecond, femtosecond, picosecond pulse width.

The picosecond laser beam having a pulse width of several picoseconds or more is mainly a photochemical reaction that is not a thermal reaction, and thus has a characteristic of enabling high-precision machining. The femtosecond laser beam with a pulse width of several femtoseconds or more can generate 10 or more equivalent when amplified¹²Megawatts output and therefore any material can be processed. Further, the femtosecond laser beam can obtain an effect of condensing photon energy onto one spot even if the laser light is not condensed onto one spot, that is, can perform processing with such high precision.

In order to make the mask pattern P have a reverse taper or a taper as a whole, one kind of laser may be intermittently or continuously irradiated in the thickness direction of the mask metal film 110, or a plurality of kinds of laser may be alternately irradiated. For example, in order to form the mask pattern P having a reverse tapered shape, a laser beam having a wide focal range may be irradiated to an upper portion of the inside of the mask metal film 110 to remove a local portion, and a laser beam having a gradually narrowed focal range may be irradiated from the inside of the mask metal film 110 to a lower portion to remove a local portion. In addition, as an example, a laser having a pulse width of nanoseconds may be irradiated to an upper portion of the mask metal film 110, and a laser having a pulse width of femtoseconds may be irradiated to a middle of the mask metal film 110, and a laser having a pulse width of picoseconds may be irradiated to a lower portion of the mask metal film 110.

On the other hand, the laser patterning LE and the etching process may be performed in combination to make the mask pattern P have a reverse taper or a taper as a whole. For example, an insulating portion (not shown) is formed on the mask metal film 110 by using a photoresist or the like, and then the mask metal film is etched to a thin thickness without penetrating the mask metal film. The etching may be performed with a relatively wide width. Next, the LE is laser-patterned to the extent of penetrating the mask metal film 110. Laser patterning LE is performed with a narrower width compared to the etching process. Accordingly, the portions removed by the etching and laser patterning LE are connected, and thus the mask pattern P may be formed.

Next, referring to fig. 13 (e), the fabrication of the template 50 for supporting the mask 100 may be finished. The mask metal film 110 portion of the laser-patterned LE constitutes a mask pattern P, so that the mask 100 formed with a plurality of mask patterns P can be manufactured.

Since the frame 200 has a plurality of mask cell regions CR (CR11-CR56), it may also have a plurality of masks 100, the masks 100 including mask cells C (C11-C56) corresponding to each mask cell region CR (CR11-CR 56). Also, there may be a plurality of templates 50 that support a plurality of masks 100, respectively.

Referring to fig. 15, the template 50 may be transferred by a vacuum chuck 90. The mask 100 is transferred by sucking the surface of the stencil 50 opposite to the surface thereof to which the mask is bonded by a vacuum chuck 90. The vacuum chuck 90 may be connected to a moving means (not shown) for moving to x, y, z, and θ axes. The vacuum chuck 90 may be connected to a flip means (not shown) for flipping (flip) the suction template 50. As shown in fig. 15 (b), even in the process of transferring the template 50 to the frame 200 after the vacuum chuck 90 sucks and inverts it, the adhesion state and the alignment state of the mask 100 are not affected.

Fig. 16 is a schematic view showing a state in which a mask is mounted on a frame so as to correspond to a cell region of the frame according to an embodiment of the present invention. Although fig. 16 illustrates an example in which one mask 100 is associated with and attached to the cell regions CR, a process may be performed in which a plurality of masks 100 are simultaneously associated with the cell regions CR, respectively, so that the masks 100 are attached to the frame 200. At this time, there may be a plurality of templates 50 for respectively supporting a plurality of masks 100.

Then, referring to fig. 16, the mask 100 may correspond to one mask unit region CR of the frame 200. The mask 100 is corresponded to the mask unit region CR by loading the stencil 50 onto the frame 200 or the mask unit sheet part 220. Whether the mask 100 corresponds to the mask unit region CR or not can be observed through a microscope while controlling the position of the template 50/vacuum chuck 90. Since the template 50 presses the mask 100, the mask 100 and the frame 200 may be closely abutted.

On the other hand, the lower support 70 may be disposed at a lower portion of the frame 200. The lower support 70 has a size that can enter the inside of the hollow region R of the frame edge portion 210 and is flat in shape. In addition, a predetermined supporting groove (not shown) corresponding to the shape of the mask unit sheet portion 220 may be formed on the upper surface of the lower supporting body 70. At this time, the edge sheet part 221, the first grid sheet part 223, and the second grid sheet part 225 are inserted into the supporting grooves, so that the mask unit sheet part 220 is more securely fixed.

The lower supporter 70 may press an opposite surface of the mask unit region CR in contact with the mask 100. That is, the lower supporter 70 supports the mask die portions 220 upward, so that the mask die portions 220 can be prevented from drooping downward during the attachment of the mask 100. At the same time, the lower supporter 70 and the stencil 50 press the edge portion of the mask 100 and the frame 200 (or the mask die section 220) in opposite directions to each other, so that the alignment state of the mask 100 is not damaged and maintained.

As such, the corresponding process of the mask 100 and the mask unit region CR of the frame 200, which does not apply any tensile force to the mask 100, can be completed only by attaching the mask 100 on the template 50 and loading the template 50 on the frame 200.

Next, the mask 100 is irradiated with the laser L to attach the mask 100 to the frame 200 by laser welding. The welded portion of the laser welded mask generates a weld 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. 17 is a schematic view illustrating 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. 17, after the mask 100 is attached to the frame 200, the mask 100 and the stencil 50 may be separated (bonding). The separation between the mask 100 and the template 50 may be performed 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 maintains the state of being attached to the frame 200, only the stencil 50 may be lifted. As an example, if heat ET higher than 85 ℃ -100 ℃ is applied, the viscosity of the temporary bonding portion 55 is lowered, and the adhesive force of the mask 100 and the stencil 50 is weakened, so that the mask 100 and the stencil 50 can be separated. As another example, the temporary bonding portion 55 is dipped in a chemical such as IPA, acetone, or ethanol, and the mask 100 and the template 50 are separated by dissolving or removing the temporary bonding portion 55. As still another example, if the ultrasonic waves US are applied or the ultraviolet rays UV are applied, the adhesive force between the mask 100 and the stencil 50 becomes weak, so that the mask 100 and the stencil 50 can be separated.

Further, since the temporary bonding part 55 bonding the mask 100 and the template 50 is a TBDB bonding material (bonding & bonding adhesive), various separation (bonding) methods may be used.

As an example, a Solvent stripping (Solvent stripping) method based on chemically treated CM may be used. Penetration of the solvent (solvent) causes the temporary bonding portion 55 to dissolve, thereby effecting peeling. At this time, since the pattern P is formed on the mask 100, the solvent penetrates through the mask pattern P and the interface between the mask 100 and the template 50. The solvent stripping method can be performed at a normal temperature (room temperature) and does not require other complicated stripping equipment, and thus is economical compared to other stripping methods.

As yet another example, a Heat stripping (Heat stripping) method based on heating ET may be used. The temporary bonding portion 55 is thermally induced to be decomposed at a high temperature, and if the bonding force between the mask 100 and the stencil 50 is lowered, the peeling can be performed in the vertical direction or the horizontal direction.

As yet another example, a peel-off (Peelable Adhesive bonding) method based on heating ET, applying ultraviolet UV, or the like, of a release Adhesive may be used. If the temporary bonding portion 55 is a thermal release tape, the peeling can be performed by a peeling method of peeling the adhesive, which does not require a high-temperature heat treatment apparatus and an expensive heat treatment apparatus and has a relatively simple process, like the thermal peeling method.

As still another example, a Room Temperature peeling (Room Temperature peeling) method based on chemical treatment CM, application of ultrasonic waves US, application of ultraviolet rays UV, or the like may be used. If the non-stick process is performed on a part (central part) of the mask 100 or the template 50, only the edge part is adhered by the temporary adhering part 55. In addition, the solvent penetrates in the edge portion at the time of peeling, and thus peeling can be performed by dissolution of the temporary bonding portion 55. The method has the following advantages: in the process of bonding and peeling, direct damage or defects due to adhesive residue (residue) at the time of peeling or the like do not occur in the portions other than the edge regions of the mask 100 and the template 50. Further, this method has an advantage that the process cost can be relatively reduced because a high-temperature heat treatment is not required at the time of peeling, unlike the thermal peeling method.

Fig. 18 is a schematic view showing a state in which the mask 100 is attached to the frame 200 according to the embodiment of the present invention.

Referring to fig. 18, one mask 100 may be attached to one cell region CR of the frame 200.

Since the mask unit piece portions 220 of the frame 200 have a thin thickness, if the mask 100 is attached to the mask unit piece portions 220 in a state where a tensile force is applied, the tensile force remaining in the mask 100 acts on the mask unit piece portions 220 and the mask unit regions CR, and may cause deformation. Therefore, the mask 100 should be attached to the mask unit sheet part 220 without applying a tensile force to the mask 100. The present invention can accomplish the corresponding process of the mask 100 and the mask unit region CR of the frame 200 without applying any tensile force to the mask 100 only by attaching the mask 100 on the template 50 and loading the template 50 on the frame 200. Thereby, it is possible to prevent the frame 200 (or the mask die section 220) from being deformed by the tensile force applied to the mask 100 acting as a tension (tension) in reverse to the frame 200.

Whereas the prior art mask 10 of FIG. 1 includes 6 cells C1-C6, which are relatively long, the mask 100 of the present invention includes one cell C, which is relatively short, and thus the degree of PPA (pixel position acquisition) distortion is reduced. For example, assuming that the length of the mask 10 including the plurality of cells C1-C6, … is 1m and a PPA error of 10 μm occurs in the total length of 1m, the mask 100 of the present invention may change the above error range to 1/n as the relative length decreases (corresponding to a decrease in the number of cells C). For example, when the length of the mask 100 of the present invention is 100mm, the length is reduced from 1m to 1/10 of the conventional mask 10, and thus a PPA error of 1 μm occurs in the total length of 100mm, which has an effect of significantly reducing the alignment error.

On the other hand, if the mask 100 has a plurality of cells C and even if the correspondence of the respective cells C to the respective cell regions CR of the frame 200 is still within the range in which the alignment error is minimized, the mask 100 may correspond to the plurality of mask cell regions CR of the frame 200. Alternatively, the mask 100 having a plurality of cells C may correspond to one mask cell region CR. At this time, the mask 100 also preferably has as few cells C as possible in view of alignment-based process time and productivity.

Since the present invention only needs to correspond to one cell C of the mask 100 and confirm the alignment state, the manufacturing time can be significantly reduced as compared to the conventional method [ refer to fig. 2] in which a plurality of cells C (C1-C6) are simultaneously corresponding and all the alignment states need to be confirmed.

That is, the method of manufacturing the frame-integrated mask of the present invention can significantly reduce time by 6 processes of respectively corresponding the cells C11 to C16 included in the 6 masks 100 to one cell region CR11 to CR16 and confirming the alignment state of each cell, compared to the conventional method of simultaneously matching 6 cells C1 to C6 and simultaneously confirming the alignment state of 6 cells C1 to C6.

In addition, in the method of manufacturing the frame-integrated mask of the present invention, the yield of the product in the 30 processes in which 30 masks 100 are respectively aligned to correspond to 30 cell regions CR (CR11-CR56) is significantly higher than the yield of the existing product in the 5 processes in which 5 masks 10 (refer to fig. 2 (a)) respectively including 6 cells C1-C6 are aligned to correspond to the frame 200. Since the existing method of aligning 6 cells C1-C6 at the region corresponding to 6 cells C at a time is significantly cumbersome and difficult to operate, the product yield is low.

In addition, in (b) of fig. 12, as described above, when the mask metal film 110 is adhered to the stencil 50 through the lamination process, a temperature of about 100 ℃ may be applied to the mask metal film 110. Based on this, the mask metal film 110 is bonded to the stencil 50 in a state where a partial tensile force is applied. Then, the mask 100 is attached to the frame 200, and if the mask 100 is separated from the stencil 50, the mask 100 will shrink by a predetermined degree.

If the template 50 is separated from the masks 100 after the respective masks 100 are attached to the mask unit regions CR corresponding thereto, the plurality of masks 100 apply a contracting tension in opposite directions, and thus the force is offset, so that the mask unit sheet portions 220 are not deformed. For example, in the first grid sheet portion 223 between the mask 100 attached to the CR11 cell region and the mask 100 attached to the CR12 cell region, the tension acting in the right direction of the mask 100 attached to the CR11 cell region and the tension acting in the left direction of the mask 100 attached to the CR12 cell region are cancelled out with each other. Thus, deformation of the frame 200 or the mask die portion 220 due to the tension is minimized, and thus an alignment error of the mask 100 or the mask pattern P can be minimized.

Fig. 19 is a schematic view illustrating an OLED pixel deposition apparatus 1000 using frame-integrated

masks

100 and 200 according to an embodiment of the present invention.

Referring to fig. 19, the OLED pixel deposition apparatus 1000 includes: a magnetic plate 300 accommodating the magnet 310 and provided with a cooling water pipe 350; and a deposition source supplier 500 for supplying an organic material source 600 from a lower portion of the magnetic plate 300.

A target substrate 900 such as glass for depositing the organic material source 600 may be inserted between the magnetic plate 300 and the deposition source supplier 500. The frame-integrated mask 100, 200[ or FMM ] for depositing the organic material source 600 in different pixels may be disposed on the target substrate 900 in close contact or close proximity. The magnet 310 may generate a magnetic field and be attached to the target substrate 900 by the magnetic field.

The deposition source supply part 500 may supply the organic material source 600 while reciprocating the left and right paths, and the organic material source 600 supplied from the deposition source supply part 500 may be deposited on one side of the target substrate 900 after passing through the pattern P formed on the frame-integrated

masks

100 and 200. The organic source 600 deposited after the pattern P of the frame-integrated

mask

100, 200 may be used as the pixel 700 of the OLED.

In order to prevent the uneven deposition of the pixels 700 occurring due to the Shadow Effect, the pattern of the frame-integrated

mask

100, 200 may be formed S obliquely [ or formed in a tapered shape S ]. The organic source 600 passing through the pattern in the diagonal direction along the inclined surface contributes to the formation of the pixel 700, and thus the pixel 700 can be deposited with uniform thickness as a whole.

The mask 100 is attached and fixed to the frame 200 at a first temperature higher than the temperature of the pixel deposition process, so that the position of the mask pattern P is hardly affected even if the temperature is raised to the temperature for the pixel deposition process, and the PPA between the mask 100 and the adjacent mask 100 can be maintained not more than 3 μm.

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.

Claims

1. A method of manufacturing a mask for forming an OLED pixel, wherein the method comprises the steps of:

(a) preparing a mask metal film; and

(b) a mask pattern is formed on one surface of the mask metal film by laser patterning.

2. The method for manufacturing a mask according to claim 1,

in step (b), the laser has a pulse width of any one of nanosecond, femtosecond and picosecond.

3. The method for manufacturing a mask according to claim 1,

in the step (b), laser light having a wide focal range is irradiated onto the upper portion of the mask metal film, and laser light having a narrower focal range is irradiated onto the lower portion of the mask metal film, based on the thickness direction of the mask metal film, to perform laser patterning.

4. The method for manufacturing a mask according to claim 1,

5. A method of manufacturing a mask supporting template for supporting a mask for OLED pixel formation and making the mask correspond to a frame, wherein the method comprises the steps of:

(a) preparing a mask metal film;

(b) bonding a mask metal film to a template having a temporary bonding portion formed on one surface thereof; and

(c) the mask is manufactured by forming a mask pattern on one surface of the mask metal film by laser patterning.

6. The method of manufacturing a mask support template according to claim 5,

in step (c), the laser has a pulse width of any one of nanosecond, femtosecond and picosecond.

7. The method of manufacturing a mask support template according to claim 5,

in the step (c), laser patterning is performed by irradiating the mask metal film with laser light having a wide focal range at an upper portion thereof and irradiating the mask metal film with laser light having a narrower focal range at a lower portion thereof, based on the thickness direction of the mask metal film.

8. The method of manufacturing a mask support template according to claim 5,

9. The method of manufacturing a mask support template according to claim 5,

the temporary bonding portion is an adhesive or an adhesive sheet that can be separated by heating, or an adhesive sheet that can be separated by irradiation with ultraviolet rays.

10. A method of manufacturing a frame-integrated type mask, the frame-integrated type mask being formed of at least one mask and a frame for supporting the mask as one body, wherein the method comprises the steps of:

(a) loading the template manufactured by the manufacturing method of claim 5 onto a frame having at least one mask unit region so that the mask corresponds to the mask unit region of the frame; and

(b) the mask is attached to the frame.