CN112740438A

CN112740438A - Frame-integrated mask and method for manufacturing frame-integrated mask

Info

Publication number: CN112740438A
Application number: CN201980062038.2A
Authority: CN
Inventors: 李裕进
Original assignee: Wuluomao Materials Co ltd
Current assignee: Wuluomao Materials Co ltd
Priority date: 2018-10-10
Filing date: 2019-10-07
Publication date: 2021-04-30
Also published as: KR20200040474A; TWI829779B; WO2020076020A1; TW202028856A

Abstract

The present invention relates to a frame-integrated mask and a method for manufacturing the frame-integrated mask. The present invention relates to a frame-integrated mask, which is formed by integrating a plurality of masks (100) with a frame (200) for supporting the masks (100), wherein the frame (200) comprises: an edge frame section (210) including a hollow region (R); and a mask unit sheet part (220) having a plurality of mask unit regions (CR) and connected to the edge frame part (210), wherein each mask is formed of a metal sheet (sheet) manufactured by a rolling process, and each mask (100) is connected to an upper part of the mask unit sheet part (200).

Description

Frame-integrated mask and method for manufacturing frame-integrated mask

Technical Field

The present invention relates to a frame-integrated mask and a method for manufacturing the frame-integrated mask. More particularly, the present invention relates to a frame-integrated mask and a method for manufacturing the frame-integrated mask, which can integrate a mask and a frame and accurately align (align) the masks.

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 fixing the mask to the frame by welding, the mask film has a problem that the mask is too thin and large in area, and therefore the mask is sagged or distorted by a load.

In the Ultra-High Definition OLED, the conventional QHD (Quarter High Definition) image quality is 500-600PPI (pixel per inch), the size of the pixel reaches about 30-50 μm, and the 4K UHD (Ultra High Definition) and 8K UHD High Definition have higher resolutions of-860 PPI and-1600 PPI than the above. Thus, in consideration of the pixel size of the ultra-high-definition OLED, it is necessary to reduce the alignment error between the units to a few μm, and exceeding this error results in poor product and possibly extremely low yield. 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

The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to provide a frame-integrated mask and a method of manufacturing the frame-integrated mask, which can form an integrated structure of a mask and a frame.

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

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

Technical scheme

The above object of the present invention is achieved by a frame-integrated mask integrally formed with a plurality of masks and a frame for supporting the masks, wherein the frame includes: an edge frame portion including a hollow region; and a mask unit sheet part having a plurality of mask unit regions and connected to the edge frame part, each of the masks being formed of a sheet metal (sheet) manufactured through a rolling process, and each of the masks being connected to an upper portion of the mask unit sheet part.

The mask unit sheet part may have a plurality of mask unit regions in at least one of a first direction and a second direction perpendicular to the first direction.

The mask unit sheet part may include: an edge sheet section; at least one first grid sheet part formed to extend in a first direction and having both ends connected to the edge sheet part; and at least one second grid sheet portion formed to extend in a second direction perpendicular to the first direction and intersecting the first grid sheet portion, and having both ends connected to the edge sheet portion.

Each mask may correspond to each mask cell region.

The mask may include a mask unit formed with a plurality of mask patterns and a dummy portion around the mask unit, and at least a portion of the dummy portion may be attached to the mask unit sheet portion.

The edge frame portion may have a thickness greater than a thickness of the mask die portion, and the mask die portion may have a thickness greater than a thickness of the mask.

The mask may be formed by further thinning its thickness on a metal sheet manufactured through a rolling process.

The mask and the frame may be made of any one of invar (invar), super invar (super invar), nickel, and nickel-cobalt.

In addition, the above object of the present invention is achieved by a method of manufacturing a frame-integrated mask integrally formed of a plurality of masks and a frame for supporting the masks, wherein the method may include: (a) preparing an edge frame portion including a hollow region; (b) connecting a mask unit sheet portion having a plurality of mask unit regions to the edge frame portion; (c) corresponding a mask to a mask unit region of a mask unit sheet part, the mask being composed of a metal sheet manufactured through a rolling process; and (d) attaching at least a portion of the edge of the mask to the mask die portion.

In addition, the above object of the present invention is achieved by a method of manufacturing a frame-integrated mask integrally formed of a plurality of masks and a frame for supporting the masks, wherein the method may include: (a) preparing an edge frame portion including a hollow region; (b) connecting a planar mask die portion to the edge frame portion; (c) corresponding a mask to a mask unit region of a mask unit sheet part, the mask being composed of a metal sheet manufactured through a rolling process; and (e) attaching at least a portion of the edge of the mask to the mask die portion.

The mask unit sheet part may include an edge sheet part; at least one first grid sheet part formed to extend in a first direction and having both ends connected to the edge sheet part; and at least one second grid sheet portion formed to extend in a second direction perpendicular to the first direction and intersecting the first grid sheet portion, and having both ends connected to the edge sheet portion.

In step (b), the corner portions of the mask die portions may be welded and connected at the edge frame portions.

The step of raising the temperature of the process area including the frame to the first temperature may be further performed before or after the step of corresponding the mask to one mask unit area of the mask unit sheet part, and the step of lowering the temperature of the process area including the frame to the second temperature may be further performed after the step of attaching at least a portion of the edge of the mask to the mask unit sheet part.

The first temperature may be equal to or higher than a temperature of the OLED pixel deposition process, the second temperature may be at least lower than the first temperature, the first temperature may be any one of 25 ℃ to 60 ℃, the second temperature may be lower than the first temperature and be any one of 20 ℃ to 30 ℃, and the OLED pixel deposition process temperature may be any one of 25 ℃ to 45 ℃.

When the mask is made to correspond to the mask cell region, the mask may not be stretched.

If the temperature of the process area is lowered to a second temperature, the mask attached to the frame contracts and is subjected to tension (tension).

Effects of the invention

According to the present invention as described above, the mask and the frame can form an integrated structure.

In addition, the present invention can prevent deformation such as sagging or warping of the mask and make alignment accurate.

In addition, the invention can obviously shorten the manufacturing time and obviously improve 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 process of stretching a mask.

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 manufacturing process of a frame according to another embodiment of the present invention.

Fig. 8 is a schematic view showing a stretched state of the mask and a state in which the mask is associated with the cell region of the frame according to the embodiment of the present invention.

Fig. 9 is a schematic view illustrating a process of corresponding and attaching a mask to a cell region of a frame according to an embodiment of the present invention.

Fig. 10 is a partially enlarged cross-sectional view illustrating a state in which a mask is attached to a frame according to various embodiments of the present invention.

Fig. 11 to 13 are conceptual views illustrating a process of attaching a mask to a frame according to another embodiment of the present invention.

Fig. 14 is a schematic view of an OLED pixel deposition apparatus using a frame-integrated mask according to an embodiment of the present invention.

[ description of symbol Mark ]

100: mask and method for manufacturing the same

110: mask film

150: adhesion plated part

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

CR: mask unit region

EM: bonding of eutectic materials

ET: raising the temperature of the process zone to a first temperature

F1-F4: tensile force

LT: reducing the temperature of the process zone to a second temperature

R: hollow region of edge frame part

P: mask pattern

W: welding of

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. It is to be understood that 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 accompanying drawings so that those skilled in the art can easily practice the 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 in fig. 1 (b) is used as a plate mask in a large-area pixel formation process.

The Body (Body, or mask film 11) of the mask 10 has a plurality of display cells C. One cell C corresponds to one display (display) of a 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, a pixel pattern P is formed in the cell C so as to have 70 × 140 resolution. 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 attaching the mask 10 to the frame 20. Fig. 3 is a schematic view showing alignment errors between cells generated in a process of stretching the conventional F1 to 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), the tensile forces F1 to F2 applied to the respective sides of the strip mask 10 are finely adjusted while being aligned, and then the strip mask 10 and the frame 20 are coupled to each other as a part of the side of the W strip mask 10 is welded. 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 to F2 applied to the sides of the strip mask 10 are finely adjusted, a problem of poor alignment of the mask units C1 to C3 with respect to each other is shown. 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. The stripe mask 10 has a large area including a plurality of (for example, 6) cells C1 to C6 and a very thin thickness of several tens of μm, and therefore is liable to sag or twist due to a load. In addition, it is very difficult to adjust the tensile forces F1 to F2 so that all of the cells C1 to C6 become flat, and to confirm the alignment state of the cells C1 to C6 in real time by a microscope.

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 plurality of bar masks 10 and the plurality of cells C-C6 of the bar masks 10 while respectively connecting about 6 to 20 bar masks 10 to one frame 20, and it only increases the process time for alignment, which is an important reason for lowering productivity.

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. The mask 100 integrated with the frame 200 can prevent deformation such as sagging or twisting, and be accurately aligned with 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 will be described as an example, but the mask 100 may have a bar mask shape having protrusions for clamping on both sides before being attached to the frame 200, and the protrusions may be removed after being attached to the frame 200.

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

The mask 100 may use a sheet metal (sheet) generated through a rolling process. 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, the pattern shape of the Mask is less likely to be deformed by thermal energy, and thus, it can be used as an FMM, a Shadow Mask (Shadow Mask) in manufacturing an OLED with high resolution. In addition, considering that a technique for performing a pixel deposition process in a range in which a temperature variation value is not large has been recently developed, the mask 100 may be made of a material such as nickel (Ni) or nickel-cobalt (Ni-Co) having a slightly larger thermal expansion coefficient than that of the above.

The metal sheet manufactured through the rolling process may have a thickness of several tens to several hundreds of μm in the manufacturing process. In order to finely form the mask pattern P, which will be described later, it is necessary to make the relatively thick metal sheet having the above thickness thinner. A process of making the thickness thinner than about 50 μm by CMP or the like may be further performed on the metal sheet. The thickness of the mask is preferably about 2 μm to 50 μm, more preferably about 5 μm to 20 μm. But is not necessarily limited thereto.

In the case of using a metal sheet manufactured through a rolling process, although there is a problem in terms of thickness that it is larger than that of a plating film formed by electroforming, since the coefficient of thermal expansion CTE is low, an additional heat treatment process is not required, and there is an advantage in that corrosion resistance is strong.

The frame 200 may be formed in a form of attaching a plurality of masks 100. Including the outermost peripheral edges, 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). 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 preferably, in consideration of thermal deformation, is formed of a material such as invar, super invar, nickel-cobalt, etc., which have the same thermal expansion coefficient as the mask, and may be applied to the edge frame portion 210 and the mask unit sheet portion 220, which are members of the frame 200.

Further, the frame 200 has a plurality of mask unit regions CR, and may include a mask unit sheet portion 220 connected to the edge frame portion 210. The mask die section 220 is formed by rolling, as in the mask 100, or may be formed by another film forming process such as electroforming. 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 plurality of mask unit regions CR are formed in the mask unit sheet portion 220 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 integrally formed 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.

Although the first grid sheet portion 223 and the second grid sheet portion 225 have a thin thickness in the form of a thin film, the shape of the cross section perpendicular to the longitudinal direction may be, for example, a rectangle, a trapezoid, a quadrangle (see fig. 5(b) and 10), a triangle, or the like, and the sides and corners may be partially 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 may be formed in a thickness of several mm to several cm.

In the case of the mask unit sheet part 220, a process of manufacturing a thick sheet is difficult in practice, and if it is too thick, there is a possibility that the organic matter source 600 (refer to fig. 14) 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. Thus, 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 to 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 except for regions occupied by the edge sheet portion 221, the first grid sheet portion 223, and the second grid sheet portion 225 in the hollow region R of the edge frame portion 210.

As the cells C of the mask 100 correspond to the mask cell regions CR, they may be actually 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 a large area mask 100, preferably a small area mask 100 having one cell C. Alternatively, one mask 100 having a plurality of cells C may correspond to one cell region CR of the mask 200. At this time, in order to precisely align, it may be considered that the mask 100 having 2-3 cells C corresponds to one cell region CR of the mask 200.

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 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.

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 or other film forming processes, and then removing the mask unit region CR 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 a 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 a part of the side direction, not all of the side portions.

Then, when the mask die part 220 is corresponded to the edge frame part 210, the edge die part 221 of the mask die part 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 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 and F2 mask unit sheet portions 220' may be stretched in a part of the side direction, not all of the side portions.

Then, when 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, a mask unit sheet portion 220 may be formed 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.

Although fig. 6 and 7 illustrate an example in which the edge frame portion 210 and the mask die portion 220 are attached by welding W, the present invention is not limited to this, and may be attached by a method using a eutectic bonding portion EM, an electroformed portion 150, another organic/inorganic adhesive, or the like, which will be described later in fig. 10.

Fig. 8 is a schematic view showing a stretched state of the mask 100[ fig. 8 (a) ] and a state where the mask 100 is associated with the cell region CR of the frame 200[ fig. 8 (b) ] according to an embodiment of the present invention.

Then, the mask 100 formed with the plurality of mask patterns P may be provided. As described above, the mask 100 made of invar or super-invar material can be manufactured by rolling, and one cell C can be formed on the mask 100.

A mask pattern P may be formed on a metal sheet made with a thin thickness using a photolithography-based etching process. The width of the mask pattern P is less than 40 μm and the thickness of the mask 100 is about 2 to 50 μm, preferably about 5 to 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, each mask 100 having mask cells C (C11-C56) corresponding to each mask cell region CR (CR11-CR 56).

Referring to (a) of fig. 8, the mask 100 may correspond to one mask unit region CR of the frame 200. In the corresponding process, as shown in fig. 8 (a), the mask unit C may be made to correspond to the mask unit region CR in a state where both side portions of F1 to F4 are stretched in the one-axis direction of the mask 100 to make the mask 100 in a flat stretched state. The mask 100 may be clamped and stretched at multiple points (1-3 points in the example of fig. 8) on one side. On the other hand, all side portions of the F1-F4 mask 100 may be stretched not in one axis direction but in all axis directions.

For example, the tensile force applied to each side of the mask 100 may not exceed 4N. The applied stretching force may be the same or different depending on the size of the mask 100. In other words, the mask 100 of the present invention is sized to include 1 mask cell C, and thus the required tensile force may be equal, or at least less likely, than the conventional strip mask 10 including a plurality of cells C1-C6. Considering that 9.8N represents a gravity of 1kg, 1N is a gravity of less than 400g, and thus even if the mask 100 is attached to the frame 200 after being stretched, a tension (tension) applied to the frame 200 by the mask 100 or a tension applied to the mask 100 in reverse by the frame 200 is very small. Accordingly, deformation of the mask 100 and/or the frame 200 due to the tension is minimized, so that an alignment error of the mask 100[ or the mask pattern P ] may be minimized.

In addition, the conventional mask 10 of FIG. 1 includes 6 cells C1-C6, and thus has a longer length, whereas the mask 100 of the present invention includes one cell C, and thus has a shorter length, and thus the degree of PPA distortion becomes smaller. 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-described error range to 1/n as the relative length decreases (corresponding to a decrease in the number of cells C). For example, if the mask 100 of the present invention has a length of 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 a total length of 100mm, having an effect of significantly reducing an 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 preferably has as few cells C as possible in consideration of alignment-based process time and productivity.

The mask 100 may correspond to the mask cell region CR in a flat state by adjusting the tensile forces F1 to F4, while the alignment state may be confirmed in real time by a microscope. In the present invention, since it is only necessary to match one cell C of the mask 100 and confirm the alignment state, the manufacturing time can be significantly reduced compared to the conventional method in which a plurality of cells C (C1-C6) are simultaneously matched 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.

On the other hand, after the mask 100 is attached to the frame 200, the mask 100 may be temporarily fixed to the frame 200 by a predetermined adhesive. Then, an attaching step of the mask 100 may be performed.

Fig. 9 is a schematic view illustrating a process of corresponding and attaching the mask 100 to the cell region CR of the frame 200 according to an embodiment of the present invention. Fig. 10 is a sectional view B-B' of fig. 9, showing a partially enlarged sectional view of a state in which the mask 100 is attached to the frame 200[ the first grid sheet portion 223] according to various embodiments of the present invention.

Then, referring to fig. 9, 10 (a) and (b), a part or all of the edge of the mask 100 may be attached to the frame 200. The attachment may be performed in a welding W manner, and preferably, may be performed in a laser welding W manner. The portions of the weld W may have the same material as the mask 100/frame 200 and be integrally connected.

When laser light is irradiated to an upper portion of an edge portion (or a dummy portion) of the mask 100, a portion of the mask 100 may be melted and welded W with the frame 200. The welding W should be performed close to the corner side of the frame 200 to the maximum extent so that the tilting space between the mask 100 and the frame 200 can be minimized and the adhesion can be improved. The welding W portion may be generated in a line (line) or spot (spot) shape, has the same material as the mask 100, and may become a medium for integrally connecting the mask 100 and the frame 200.

The form in which one edge of each of two adjacent masks 100 is attached W to the upper surface of the first grid sheet portion 223 (or the second grid sheet portion 225) is shown. The width and thickness of the first grid sheet portion 223 (or the second grid sheet portion 225) may be about 1 to 5mm, and in order to improve the product productivity, it is necessary to reduce the width of the overlap of the edges of the first grid sheet portion 223 (or the second grid sheet portion 225) and the mask 100 to about 0.1 to 2.5mm as much as possible.

The cross-sectional shape perpendicular to the longitudinal direction of the first and second

grid sheet portions

223, 225 may be a flat quadrangle, trapezoid, or the like.

The welding W method is only one of the methods of attaching the mask 100 to the frame 200, and the present invention is not limited to these embodiments.

Other examples are explained below, and as shown in fig. 10 (c), the mask 100 may be bonded to the frame 200 using a bonding portion EM of a eutectic material. The bonding portion EM of the eutectic material is an adhesive containing at least two metals, may have various shapes such as a thin film, a wire, a bundle, etc., and may have a thin thickness of about 10 to 30 μm. For example, the adhesion portion EM of the eutectic material may contain at least one metal selected from the group of In, Sn, Bi, Au, and the like, and the group of Sn, Bi, Ag, Zn, Cu, Sb, Ge, and the like. The bonding portion EM of the eutectic material comprises at least two solid phases of metal (liquid phases) which both can be liquid phases in a eutectic point (eutectic point) at a certain temperature/pressure. Further, if the eutectic point is deviated, the two metal solid phases are changed again. Thus, the phase change process of solid phase- > liquid phase- > solid phase can play the role of the adhesive.

Unlike a general organic adhesive, the eutectic bonding portion EM does not contain any volatile organic substance at all. Therefore, it is possible to prevent the volatile organic substances of the adhesive from reacting with the process gas to adversely affect the pixels of the OLED, or to prevent the outgassing of organic substances and the like contained in the adhesive itself from contaminating the pixel process chamber or from adversely affecting the OLED pixels due to the deposition of impurities. Moreover, the eutectic bonding part EM is solid, so the eutectic bonding part EM cannot be cleaned by the OLED organic cleaning liquid, and the eutectic bonding part EM has corrosion resistance. Further, since two or more metals are contained as compared with the organic adhesive, the mask 100 and the frame 200 made of the same metal material can be connected with higher adhesion, and since the mask is made of a metal material, the possibility of deformation is low.

For another example, as shown in fig. 10 (d), an adhesion plating part 150 having the same material as that of the mask 100 may be further formed to adhere the mask 100 to the frame 200. After the mask 100 is corresponded to the frame 200, an insulating portion such as PR may be formed below the mask 100. Also, the adhesion plating part 150 may be electrodeposited on the back surface of the mask 100 and the frame 200, which are not covered with the insulating part and are exposed.

When the adhesion plating part 150 is electrodeposited on the exposed surface of the mask 100 and the frame 200, the adhesion plating part 150 may serve as a medium for integrating the mask 100 and the frame 200. At this time, since the adhesion plated part 150 is integrally connected to the edge portion of the mask 100 and electrodeposited, the mask 100 may be supported in a state where a tensile force is applied to the inside or outside direction of the frame 200. Accordingly, the mask 100 tensioned to the frame 200 side can be integrated with the frame 200 without an additional process of stretching and aligning the mask.

It should be noted that, for convenience of explanation, the thickness and width of the welding W portion and the eutectic material bonding portion EM portion are more or less exaggerated in fig. 10, and in fact, the welding W portion and the eutectic material bonding portion EM portion may be a portion which is hardly protruded and is connected to the frame 200 in a state of being included in the mask 100.

Then, after the process of attaching one mask 100 to the frame 200 is finished, the process of sequentially corresponding the remaining masks 100 to the remaining mask units C and attaching to the frame 200 may be repeated. Since the mask 100 having been attached to the frame 200 can provide the reference position, it is possible to significantly shorten the time of the process of sequentially corresponding the remaining masks 100 to the cell region CR and confirming the alignment state. Furthermore, the PPA between the mask 100 attached to one mask cell region and the mask 100 attached to the adjacent mask cell region is not more than 3 μm, and it is possible to provide an ultra-high-definition OLED pixel formation mask with accurate alignment.

Fig. 11 to 13 are schematic views illustrating a process of attaching a mask to a frame according to another embodiment of the present invention.

Referring to fig. 11 (a), a mask 100 formed with a plurality of mask patterns P may be provided. The process is the same as in (a) of fig. 8.

Then, referring to fig. 11 (b), the mask 100 may correspond to one mask unit region CR of the frame 200. Another embodiment of the present invention is characterized in that any tensile force is not applied to the mask 100 during the process of corresponding the mask 100 to the mask cell region CR of the frame 200.

Since the mask unit sheet portions 220 of the frame 200 have a thin thickness, if the mask unit sheet portions 220 are bonded to the mask 100 in a state where a tensile force is applied to the mask 100, the tensile force remaining in the mask 100 may act on the mask unit sheet portions 220 and the mask unit regions CR, thereby causing deformation. Therefore, the mask 100 should be attached to the mask unit sheet portion 220 without applying a tensile force to the mask 100. Accordingly, it is possible to prevent the frame 200 (or the mask die section 220) from being deformed due to a tensile force applied to the mask 100 acting as a tension (tension) against the frame 200.

However, there is a possibility that a problem may occur when the frame-integrated mask is manufactured by attaching the mask 100 to the frame 200 (or the mask die part 220) without applying a tensile force thereto and applied to a pixel deposition process. The mask 100 is thermally expanded by a predetermined length in a pixel deposition process at about 25 to 45 deg.c. Even for the mask 100 of invar alloy material, a length change of about 1 to 3ppm occurs as the temperature of the deposition process environment for forming the pixel is raised by about 10 ℃. For example, when the total length of the mask 100 is 500mm, the length is lengthened by about 5 to 15 μm. Since the mask 100 is sagged by its own weight or stretched in a state of being fixed to the frame 200, deformation such as distortion occurs, and an alignment error of the pattern P becomes large.

Therefore, the present invention is characterized in that the mask 100 is attached to the mask unit region CR of the frame 200 while being aligned with the mask unit region CR without applying a tensile force thereto, not at normal temperature but at a temperature higher than normal temperature. It is stated herein that the mask 100 is aligned with and attached to the frame 200 after raising the temperature of the process region to the first temperature ET.

The "process area" refers to a space where the components of the mask 100, the frame 200, and the like are arranged and an attaching process of the mask 100 and the like are performed. The process area may be a space within the closed chamber or may be an open space. In addition, the "first temperature" may refer to a temperature higher than or equal to a pixel deposition process when the frame-integrated mask is used for the OLED pixel deposition process. The first temperature may be about 25 to 60 deg.c considering that the pixel deposition process temperature is about 25 to 45 deg.c. The temperature of the process field may be raised by providing a heating device in the chamber or by providing a heating device around the process field.

Referring again to (b) of fig. 11, after the mask 100 is corresponded to the mask cell region CR, the temperature of the process region including the frame 200 may be raised to the first temperature ET. Alternatively, the mask 100 may be aligned with the mask unit region CR after raising the temperature of the process region including the frame 200 to the first temperature. Although it is shown in the drawings that only one mask 100 corresponds to one mask cell region CR, the temperature of the process region may be raised to the first temperature ET after each mask cell region CR corresponds to the mask 100.

Then, referring to fig. 12, a portion or all of the edge of the mask 100 may be attached to the frame 200. The process is the same as in fig. 9 and 10.

Then, referring to fig. 13, the temperature of the process area is lowered to a second temperature LT. The "second temperature" may refer to a temperature lower than the first temperature. Considering that the first temperature is about 25 to 60 c, the second temperature may be about 20 to 30 c, provided that it is lower than the first temperature, and preferably, the second temperature may be normal temperature. The temperature of the process field may be lowered by providing a cooling device in the chamber, providing a cooling device around the process field, naturally cooling at room temperature, or the like.

If the temperature of the process area is lowered to the second temperature LT, the mask 100 may be heat-shrunk by a predetermined length. The mask 100 may be heat shrunk isotropically in all lateral directions. However, since the mask 100 is fixedly attached to the frame 200 (or the mask die portions 220) by the welding W, the thermal contraction of the mask 100 spontaneously applies a tension TS to the surrounding mask die portions 220. Since the mask 100 spontaneously applies tension, the mask 100 can be more tightly attached to the frame 200.

In addition, after all the masks 100 are attached to the corresponding mask unit regions CR, the temperature of the process region is lowered to the second temperature LT, and thus the masks 100 are simultaneously thermally shrunk, and thus the problems of deformation of the frame 200 or increase of the alignment error of the pattern P can be prevented. More specifically, even though the tension TS is applied to the mask die sheet portion 220, since the plurality of masks 100 apply the tension TS in opposite directions, the force is offset, so that the mask die sheet portion 220 is 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 TS acting in the right direction of the mask 100 attached to the CR11 cell region and the tension TS acting in the left direction of the mask 100 attached to the CR12 cell region cancel each other out. Thus, deformation of the frame 200 (or the mask die part 220) due to the tension TS may be minimized, thereby minimizing alignment errors of the mask 100 (or the mask pattern P).

Fig. 14 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. 14, 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 supply part 500 for supplying the organic material 600 from a lower part 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 masks 100 and 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 substance source 600 while reciprocating the left and right paths, and the organic substance source 600 supplied from the deposition source supply part 500 may be deposited on one side of the target substrate 900 by 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 and 200 may function as a pixel 700 of an 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.

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 frame-integrated type mask formed by integrating a plurality of masks and a frame for supporting the masks, wherein,

the frame includes:

an edge frame portion including a hollow region; and

a mask unit sheet part having a plurality of mask unit regions and connected to the edge frame part,

each mask is made of a metal sheet manufactured through a rolling process,

each mask is connected to an upper portion of the mask die section.

2. The frame integrated type mask of claim 1,

the mask unit sheet portion has a plurality of mask unit regions in at least one of a first direction and a second direction perpendicular to the first direction.

3. The frame integrated type mask of claim 1, wherein the mask die section comprises:

an edge sheet section;

at least one first grid sheet part formed to extend in a first direction and having both ends connected to the edge sheet part; and

and at least one second grid sheet part formed to extend in a second direction perpendicular to the first direction and intersecting the first grid sheet part, and having both ends connected to the edge sheet part.

4. The frame integrated type mask of claim 1,

each mask corresponds to each mask cell region.

5. The frame integrated type mask of claim 4, wherein,

the mask includes a mask unit having a plurality of mask patterns formed thereon and a dummy portion around the mask unit,

at least a portion of the dummy portion is attached to the mask die portion.

6. The frame integrated type mask of claim 1,

the thickness of the edge frame portion is greater than the thickness of the mask die portion, and the thickness of the mask die portion is greater than the thickness of the mask.

7. The frame integrated type mask of claim 1,

the mask is formed by further thinning its thickness on a metal sheet manufactured through a rolling process.

8. The frame integrated type mask of claim 1,

the mask and the frame are made of any one of invar alloy, super invar alloy, nickel and nickel-cobalt.

9. A method of manufacturing a frame-integrated mask, the frame-integrated mask being formed of a plurality of masks and a frame for supporting the masks, wherein the method comprises the steps of:

(a) preparing an edge frame portion including a hollow region;

(b) connecting a mask unit sheet portion having a plurality of mask unit regions to the edge frame portion;

(c) corresponding a mask to a mask unit region of a mask unit sheet part, the mask being composed of a metal sheet manufactured through a rolling process; and

(d) at least a portion of an edge of the mask is attached to the mask die portion.

10. A method of manufacturing a frame-integrated mask, the frame-integrated mask being formed of a plurality of masks and a frame for supporting the masks, wherein the method comprises the steps of:

(a) preparing an edge frame portion including a hollow region;

(b) connecting the planar mask unit sheet part to the edge frame part;

(c) forming a plurality of mask unit regions in the mask unit sheet portion;

(d) corresponding a mask to a mask unit region of a mask unit sheet part, the mask being composed of a metal sheet manufactured through a rolling process; and

(e) at least a portion of an edge of the mask is attached to the mask die portion.

11. The method of manufacturing a frame integrated type mask according to claim 9 or 10, wherein the mask die part includes:

an edge sheet section;

12. The method for manufacturing a frame integrated type mask according to claim 9 or 10,

in the step (b), the corner portions of the mask die sections are welded and connected to the edge frame section.

13. The method for manufacturing a frame integrated type mask according to claim 9 or 10,

before or after the step of bringing the mask to correspond to a mask unit region of the mask unit sheet portion, a step of raising the temperature of the process region including the frame to a first temperature is further performed,

after the step of attaching at least a portion of the edge of the mask to the mask die portion, a step of lowering the temperature of the process area including the frame to a second temperature is further performed.

14. The method of manufacturing a frame-integrated mask according to claim 13,

the first temperature is equal to or higher than the temperature of the OLED pixel deposition process,

the second temperature is at least lower than the first temperature,

the first temperature is any one of 25 ℃ to 60 ℃,

the second temperature is lower than the first temperature and is any one of 20 ℃ to 30 ℃,

the OLED pixel deposition process temperature is any one of 25 ℃ to 45 ℃.

15. The method of manufacturing a frame-integrated mask according to claim 13,

when the mask is made to correspond to the mask cell region, the mask is not stretched.

16. The method of manufacturing a frame-integrated mask according to claim 13,

if the temperature of the process area is lowered to the second temperature, the mask attached to the frame contracts and is subjected to tension.