CN112639156A - Method for manufacturing frame-integrated mask and frame - Google Patents

Abstract

The present invention relates to a method for manufacturing a frame-integrated mask. The present invention relates to a method for manufacturing a frame-integrated mask, which integrates at least one mask with a frame for supporting the mask, wherein the method comprises the steps of: (a) providing a frame having at least one mask cell region; (b) providing a mask; (c) corresponding the mask to the mask unit area of the frame; and (d) irradiating laser to the welding portion of the mask and bonding the mask to the frame, the plurality of suction holes being formed at portions spaced apart from corners of the frame having the mask unit regions by a predetermined distance, and in the step (c), applying suction force to the mask contacted to the frame through the plurality of suction holes to closely attach the mask to the frame.

Description

Method for manufacturing frame-integrated mask and frame

Technical Field

The present invention relates to a method for manufacturing a frame-integrated mask and a frame. More specifically, a method of manufacturing a frame-integrated mask and a frame, which can stably support and move a mask without deforming the mask, improve the adhesion between the mask and the frame when bonding the mask to the frame, and make the 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 for manufacturing a frame-integrated mask and a frame, which can prevent the mask from being deformed when the mask is bonded to the frame and improve the adhesion between the mask and the 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 frame-integrated mask in which at least one mask is integrated with a frame for supporting the mask, comprising the steps of: (a) providing a frame having at least one mask cell region; (b) providing a mask; (c) corresponding the mask to the mask unit area of the frame; and (d) irradiating laser to the welding portion of the mask and bonding the mask to the frame, the plurality of suction holes being formed at portions spaced apart from corners of the frame having the mask unit regions by a predetermined distance, and in the step (c), applying suction force to the mask contacted to the frame through the plurality of suction holes to closely attach the mask to the frame.

The step (b) may comprise the steps of: (b1) forming a mask metal film on at least one surface of the conductive substrate by electroforming; (b2) separating the mask metal film from the conductive substrate; (b3) bonding a mask metal film to a template having a temporary bonding portion formed on one surface thereof; and (b4) forming a mask pattern on the mask metal film and manufacturing a mask.

The step (b) may comprise the steps of: (b1) providing a film-like mask metal film produced by rolling; (b2) bonding a mask metal film to a template having a temporary bonding portion formed on one surface thereof; (b3) a mask pattern is formed on the mask metal film and a mask is manufactured.

The step (c) may be a step of loading the template onto the frame and corresponding the mask to the mask unit region of the frame.

In the step (c), a lower support including an adsorption part for generating suction pressure may be disposed at a lower portion of the frame.

The lower support may press an opposite side of a mask unit region for loading a mask.

The adsorption hole may be formed at a portion that does not overlap with the welding portion of the mask.

The conductive substrate is a wafer, and a process of heat-treating the mask metal film may be further performed between the step (b1) and the step (b 2).

Between the step (b2) and the step (b3), a step of reducing the thickness of the mask metal film adhered to the template may be further included, and the reduction of the thickness of the mask metal film may be performed by any one of Chemical Mechanical Polishing (CMP), Chemical wet etching (wet etching), and dry etching (dry etching).

The temporary bonding portion may be a heat-releasable adhesive or bonding sheet and a radiation-UV-releasable adhesive or bonding sheet.

The forming of the mask pattern on the mask metal film and the manufacturing of the mask may include: (1) forming a patterned insulating portion on the mask metal film; (2) etching the exposed part of the mask metal film between the insulating parts to form a mask pattern; and (3) removing the insulation.

The template material may include wafer (wafer), glass (glass), silicon dioxide (silica), pyrex, quartz (quartz), alumina (Al)₂O₃) A borosilicate glass (borosilicate glass) or zirconia (zirconia).

The laser irradiated from the upper portion of the mask may be irradiated onto the welding portion of the mask through the laser passage hole.

The method may further include a step of separating the mask from the template by any one of heating, chemical treatment, and application of ultrasonic waves to the temporary bonding portion after the step (d).

The frame may include an edge frame portion and a mask die portion, the mask die portion including: 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 part formed to extend in a second direction perpendicular to the first direction, intersecting the first grid sheet part, and having both ends connected to the edge sheet part.

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

The above object of the present invention is achieved by a frame for a frame-integrated mask in which a plurality of masks and a frame for supporting the masks are integrally formed, the frame including: an edge frame portion including a hollow region; and a mask unit sheet portion having a plurality of mask unit regions along at least one of a first direction and a second direction perpendicular to the first direction and connected to the edge frame portion, the mask unit sheet portion having a plurality of suction holes formed therein.

A plurality of suction holes are formed at a portion spaced apart from a corner of the frame having the mask unit region by a predetermined distance, and the suction holes may be formed at a portion not overlapping the welding portion of the mask.

The lower portion of the frame may be further provided with a lower support including an adsorption portion for generating suction pressure.

The lower support is formed with at least one vacuum channel which can be used for transmitting the suction pressure generated by the external suction pressure generating device to the suction part.

Effects of the invention

According to the present invention configured as above, when the mask is bonded to the frame, the mask can be prevented from being deformed and the adhesiveness between the mask and the frame can be improved.

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 of a conventional OLED pixel deposition mask.

Fig. 2 is a schematic view of a conventional process of bonding a mask to a frame.

Fig. 3 is a schematic view of alignment errors between cells occurring in a conventional mask stretching process.

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

FIG. 5 is a front view and a side cross-sectional view of a frame according to an embodiment of the invention.

Fig. 6 is a diagrammatic view of a frame manufacturing process in accordance with an embodiment of the present invention.

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

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

Fig. 9 is a schematic view of a process of manufacturing a mask metal film by electroforming (electroforming) according to an embodiment of the present invention.

Fig. 10 is a schematic view of a process of manufacturing a mask metal film in a rolling manner according to an embodiment of the present invention.

Fig. 11-12 are schematic diagrams of a process of adhering a mask metal film to a template and forming a mask to fabricate a mask-supporting template according to an embodiment of the present invention.

Fig. 13 is a schematic view of an enlarged cross section of a temporary bonding portion according to an embodiment of the present invention.

FIG. 14 is a diagrammatic view of the process of loading a mask support stencil onto a frame in accordance with an embodiment of the present invention.

Fig. 15 is a schematic view of a state in which a template is loaded on a frame so that a mask corresponds to a cell region of the frame according to an embodiment of the present invention.

Fig. 16 is a schematic view of a state in which an adsorption force is applied to a mask through adsorption holes according to an embodiment of the present invention.

Fig. 17 is a partial schematic view of a frame formed with a plurality of adsorption holes according to an embodiment of the present invention.

Fig. 18 is a schematic view of a process of separating the mask from the stencil after bonding the mask to the frame according to an embodiment of the present invention.

Fig. 19 is a schematic view of a state in which a mask is bonded to a frame according to an embodiment of the present invention.

Fig. 20 is a schematic view of 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

75: suction part

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

229: adsorption hole

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

R: hollow region of edge frame part

P: mask pattern

VS: exerting adsorption force and pressure

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. It is to be understood that the various embodiments of the invention, although different from one another, are not 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 and all equivalents thereof, if appropriately interpreted. Like reference symbols in the drawings indicate like or similar functionality 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 of 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 of a conventional process of bonding the mask 10 to the frame 20. Fig. 3 is a schematic view of alignment errors between cells occurring in a conventional process of stretching the F1-F2 mask 10. The stripe mask 10 having 6 cells C (C1-C6) shown 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 units C-C6 of the bar masks 10 while respectively connecting about 6 to 20 bar masks 10 to one frame 20, and only the alignment-based process time is increased, which is 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 ((a) of fig. 4) and a side sectional view ((b) of fig. 4) of a frame-integrated mask according to an embodiment of the present invention, and fig. 5 is a front view ((a) of fig. 5) and a side sectional view ((b) of fig. 5) of 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 bonded 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 bonded to the frame 200, and the protrusions may be removed after being bonded 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.

To form a thinner thickness, the mask 100 may be formed by electroforming. Alternatively, the mask 100 may use a film (sheet) produced by rolling. The mask 100 may have a coefficient of thermal expansion of about 1.0 x 10^-6Invar or approximately 1.0X 10 at/° C^-7Super invar alloy 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 (Fine Metal Mask), 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.

If a rolled thin film is used, there is a problem that the thickness is greater than that of a plated film formed by electroforming, but since the Coefficient of Thermal Expansion (CTE) is low, there is an advantage that an additional heat treatment process is not required and corrosion resistance is strong.

The frame 200 is formed in a form capable of bonding 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 bonding 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 a material such as invar, super-invar, nickel-cobalt, etc., which have the same thermal expansion coefficient as the mask, in consideration of thermal deformation, and these materials may be applied to the edge frame portion 210 and the mask unit sheet portion 220, which are constituent elements 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 die portion 220, like the mask 100, may be formed by electroforming, rolling, or by other film forming processes. 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 at least one of an edge sheet portion 221, a first grid sheet portion 223, and a second grid sheet portion 225. The edge sheet portion 221, the first grid sheet portion 223, and the second grid sheet portion 225 are portions divided on the same sheet, and are 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 with both ends thereof connected to the edge sheet portion 221. The first and second grid sheet portions 223, 225 intersect perpendicularly with each other. 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 parallelogram 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.

The process of manufacturing a thick sheet is substantially difficult with the mask unit sheet part 220, and if it is too thick, there is a possibility that the organic matter source 600 (refer to fig. 20) 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. The first and second grid sheet portions 223, 225 may have a width of about 1 to 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 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 frame 200 has a plurality of mask unit regions CR, and the respective masks 100 may be bonded such that the respective mask units C correspond to the respective mask unit 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 adhered 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 bonded 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 also 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 diagrammatic view of a process for manufacturing a frame 200 in accordance with 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 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 correspond 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 make the mask cell sheet part 220 spread 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 portions 220 are corresponded to the edge frame portions 210, the edge die portions 221 of the mask die portions 220 may be bonded in a W-manner. Preferably, all sides of W are welded so that the mask die section 220 is firmly adhered 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 of a frame manufacturing process according to another embodiment of the present invention. The embodiment of fig. 6 first manufactures the mask unit sheet portions 220 provided with the mask unit regions CR and then adheres to the edge frame portion 210, while the embodiment of fig. 7 forms the mask unit region CR portions after adhering a planar sheet to the edge frame portion 210.

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, after the mask unit sheet portion 220 'is corresponded to the edge frame portion 210, the edge portion of the mask unit sheet portion 220' may be bonded in a W-manner. Preferably, all sides of W are welded so that the mask unit sheet portion 220' is firmly adhered 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 such that a portion to which the edge frame portion 210 is welded W becomes an edge sheet portion 221, and the mask unit sheet portion 220 includes 5 first grid sheet portions 223 and 4 second grid sheet portions 225.

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

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.

In particular, in order to realize a high resolution of UHD level, as shown in fig. 8 (b), fine patterning can be performed only by using a thin mask 10' having a thickness T2 of 20 μm or less. 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 of a process of manufacturing the mask metal film 100 by electroforming according to an embodiment of the present invention.

Referring to fig. 9 (a), a conductive base material 21 is prepared. In order to be able to perform electroforming, the base material 21 of the master may be a conductive material. The master plate can be used as a cathode (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, a uniform electric field cannot be applied to the cathode body of the above-described material, and thus a part of the mask metal film 110 (plating 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 implemented¹⁹The 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 at the time of electroforming, thereby enabling the uniform mask metal film 110 to be generated. 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.

Next, a case will be described assuming that a single crystal silicon wafer is used as the conductive base material 21.

Referring again to fig. 9 (a), the metal mask film 110 (or the plating film 110) can be formed on the conductive base material 21 by electroforming by using the conductive base material 21 as a master (Cathode Body) and disposing an anode Body (not shown) at a distance. The mask metal film 110 may be formed on the exposed upper surface and side surface of the conductive base material 21, and the conductive base material 21 may be disposed to face the anode body and may apply an electric field. The mask metal 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 D mask metal film 110 is cut with laser or a photoresist layer is formed on the upper portion of the mask metal film 110 and only the portion of the mask metal film 110 exposed by D is etched and removed. As shown in fig. 10 (b), the mask metal film 110 can be separated from the conductive substrate 21.

Further, before separating the mask metal film 110 from the conductive substrate 21, a heat treatment H may be performed. The present invention is characterized in that the thermal treatment H is performed before the mask metal film 110 is separated from the conductive base material 21 (or the master or the cathode) 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 bonded to only the upper surface of the conductive base material 21 is heat-treated. However, in the present invention, since the mask metal film 110 is formed not only on the upper surface of the conductive base material 21 but also on the side surfaces and the lower surface, 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 mask metal film 110 are closely 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.

Fig. 10 is a schematic view of a process of manufacturing a mask metal film in a rolling manner according to an 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 is a process of making one surface (upper surface) of the mask metal film 110 'mirror-like and thinning the upper portion of the mask metal film 110' by local removal. The planarization PS can be performed by a chemical mechanical polishing method, and any known chemical mechanical polishing 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 surface of the mask metal film 110' may be controlled in the chemical mechanical polishing 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 chemical mechanical polishing 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.

Fig. 11 to 12 are schematic views of 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. 11 (a), a template (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.

The stencil 50 is preferably made of a transparent material in order to facilitate visual observation (vision) or the like during the process of aligning and bonding the mask 100 to the frame 200. And if so, if soTransparent materials, 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, in order to prevent a void (air gap) from being generated between the interface between the template 50 and the mask metal film 110 (or the mask 100), the surface of the template 50 that contacts the mask metal film 110 may be a mirror surface. 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. Since the plurality of soldering portions may be arranged at predetermined intervals on the edge of the mask 100 or the dummy portion DM, the plurality of laser passing holes 51 may be formed corresponding thereto at predetermined intervals. As an example, since the soldering portions are disposed in plural at predetermined intervals at both side (left/right side) dummy portions DM (refer to fig. 12 (e)) of the mask 100, the laser passing holes 51 may be formed in plural at predetermined intervals at both sides (left/right side) of the mask 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 hole 51 may not be formed.

The template 50 may have a temporary bonding portion 55 formed on one surface thereof. The temporary bonding part 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 bonding the mask 100 to the frame 200.

The temporary bonding portion 55 may use an adhesive or a bonding sheet that is separable by heating; an adhesive or an adhesive sheet separable by irradiation of UV.

As an example, the temporary bonding portion 55 may use liquid wax (liquid wax). The liquid wax may be the same wax as that used in the 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 a liquid wax, has a decreased viscosity at a temperature higher than 85 to 100 c, and has an increased viscosity at a temperature lower than 85 c, and a portion of the temporary bonding portion becomes hard like a solid, so that the mask metal film 110 can be fixedly bonded to the template 50.

Then, referring to fig. 11 (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. 13 is a schematic view of 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 formed by disposing a core film 56 such as a PET film in the middle, disposing thermal release adhesive layers (57 a, 57b) that can be thermally released on both sides of the core film 56, and disposing release films/ release films 58a, 58b on the outer peripheries of the adhesive layers 57a, 57 b. The peeling temperatures of the adhesive layers 57a and 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/ release films 58a, 58b are removed, the lower surface (the second adhesive layer 57b) of the thermal release tape may be adhered to the stencil 50, and the upper surface (the 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, when the template 50 is separated from the mask 100 in fig. 18, which will be described later, the mask 100 can be separated from the template 50 and the temporary bonding portion 55 by heating the first adhesive layer 57 a.

Next, referring to fig. 11 (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. 11, 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.

In addition, when the mask metal film 110 is formed by electroforming, the step of flattening PS in fig. 11 (b) may be omitted, and the process of bonding the mask metal film 110 to the template 50 may be directly performed to form the pattern of fig. 11 (c).

Then, referring to fig. 12 (d), the patterned insulating portion 25 may be formed on the mask metal film 110. The insulating portion 25 may be formed of a photoresist material using a printing method or the like.

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

Then, referring to fig. 12 (e), the fabrication of the template 50 supporting the mask 100 may be completed by removing the insulating part 25. The mask 100 may include a mask unit C formed with a plurality of mask patterns P and a dummy portion DM around the mask unit C. The 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 the mask film 110 formed with a predetermined dummy portion pattern having a similar form to the mask pattern P. The dummy portion DM corresponds to an edge of the mask 100, and thus a part or the whole of the dummy portion DM may be adhered to the frame 200 (the mask die section 220).

The width of the mask pattern P may be less than 40 μm, and the thickness of the mask 100 may be about 2 to 50 μm.

Since the frame 200 has a plurality of mask unit regions CR (CR11 to CR56), a plurality of masks 100 including mask units C (C11 to 56) corresponding to the mask unit regions CR (CR11 to CR56) may be provided. Also, there may be a plurality of templates 50 that support a plurality of masks 100, respectively.

FIG. 14 is a diagrammatic view of the process of loading a mask support stencil into a frame in accordance with an embodiment of the present invention.

Referring to fig. 14, the template 50 may be moved 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. Further, the vacuum chuck 90 is connected to a flip means (not shown) capable of flipping (flip) to adsorb the 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. 15 is a schematic view of a state in which a template is loaded on a frame so that a mask corresponds to a cell region of the frame according to an embodiment of the present invention. Fig. 16 is a schematic view of a state where the adsorption force VS is applied to the mask through the adsorption holes 229 according to an embodiment of the present invention. Fig. 17 is a partial schematic view of a frame formed with a plurality of adsorption holes according to an embodiment of the present invention. Although fig. 15 shows an example in which one mask 100 is attached to the cell region CR, a process may be performed in which a plurality of masks 100 are simultaneously attached to the cell regions CR 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. Further, fig. 16 shows a state where the suction holes 229 are formed in the first grid sheet portion 223 and the suction force VS is applied, but it is obvious that the suction force VS may be applied to the suction holes 229 of the edge sheet portion 221 by forming the suction holes 229 in the edge sheet portion 221 and forming a predetermined step between the edge sheet portion 221 and the edge frame portion 210.

Then, referring to fig. 15, the mask 100 may correspond to one mask unit region CR of the frame 200. Correspondence of the mask 100 with the mask unit region CR may be achieved by loading the stencil 50 on the frame 200 (or the mask unit sheet part 220). Whether the mask 100 corresponds to the mask unit region CR or not can be observed through a microscope while controlling the position of the template 50/vacuum chuck 90. Since the template 50 presses the mask 100, the mask 100 and the frame 200 may be closely abutted.

Further, the present invention is characterized in that no gap is formed between the interface between the mask 100 and the frame 200, and the adsorption force VS is used in addition to the load of the template 50 in order to make them more closely contact. The frame 200 may be formed with a plurality of suction holes 229 as a path for applying the suction force VS or the suction pressure.

Referring to fig. 15 to 17, a plurality of adsorption holes 229 may be formed near corners of the frame 200 having the mask unit regions CR. Specifically, the plurality of adsorption holes 229 may be formed at portions spaced apart from the corners of the mask unit sheet part 220 by a predetermined distance, and more specifically, at portions spaced apart from the inner corners of the edge sheet part 221 by a predetermined distance and at portions spaced apart from the corners of the first and second grid sheet parts 223 and 225 by a predetermined distance.

The form, size, and the like of the plurality of suction holes 229 are not particularly limited as long as they are within a range capable of performing a vacuum suction function. However, the positions of the plurality of adsorption holes 229 preferably do not overlap with the welding portions (regions to be welded) of the mask 100. If the welding portion overlaps the adsorption hole 229, the mask 100 and the frame 200 (or the mask unit die portions 220) will not be in close contact, and thus the welding bead WB based on laser welding cannot be smoothly generated. It is preferable that a plurality of adsorption holes 229 be formed at a portion near the soldering portion so that the soldering portion of the mask 100 is brought into close contact with the frame 200 (or the mask unit die portion 220).

As shown in fig. 16, if the template 50 is mounted on the frame 200 (or the mask die sections 220), a part of the lower surface of the mask 100 abuts against the upper portion of the frame 200 (or the mask die sections 220). The upper portion of the adsorption hole 229 formed in the frame 200 (or the mask unit sheet portion 220) corresponds to the lower surface of the mask 100, and an adsorption force (or a suction pressure) applying means corresponding to the lower portion of the adsorption hole 229 applies an adsorption force VS (or a suction pressure VS) to the mask 100 through the adsorption hole 229, so that the portion of the mask 100 corresponding to the adsorption hole 229 can be pulled. This allows the mask 100 to be in close contact with the frame 200, thereby more stably generating the weld beads WB during laser welding.

As the suction force (suction pressure) applying means, a known device that performs vacuum suction at the suction holes 229 can be used. The lower support 70 including the adsorption part 75 will be described in the following embodiments.

Referring again to fig. 15 and 16, a lower support 70 may be disposed below the frame 200. The lower support 70 may be disposed on a stage (not shown) as a mounting table on which a bonding process of the mask 100 and the frame 200 is performed, and support a lower portion of the frame 200. The lower supporter 70 may be disposed at a lower portion of the frame 200, and may be disposed at a lower portion of the frame 200 during a process of bonding the mask 100 to the frame 200 to be fixedly coupled to the frame 200. The lower support 70 may be a plate shape for supporting the frame 200, and may have a size less than or equal to an area of the frame 200. Alternatively, the lower support 70 may be a flat plate shape having a size capable of entering the inside of the hollow region R of the frame edge portion 210. The lower support 70 is preferably made of the same material as the frame 200 in consideration of the thermal expansion coefficient, but may be made of a material having high rigidity. 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 lattice sheet part 223, and the second lattice sheet part 225 are inserted into the support grooves, thereby better fixing the mask unit sheet part 220.

The lower supporter 70 may have an adsorption part 75 formed at an upper portion thereof. The adsorption part 75 is preferably configured to correspond to the position of the adsorption hole 229 formed on the frame 200 (or the mask unit sheet part 220). In other words, the suction portion 75 may be disposed at a position where the suction force VS (or the suction pressure VS) is intensively applied to the suction holes 229 on the lower support 70. The suction unit 75 may be a vacuum suction device, and may be connected to an external suction pressure generating device. As an example, the lower supporter 70 is formed with a vacuum passage 76 therein, and the other end is connected to an external suction pressure generating device (not shown) such as a pump, and the other end is connected to the suction portion 75. The upper surface of the suction portion 75 connected to the vacuum passage 76 is formed with a plurality of holes, grooves, and the like, and is used as a passage for applying suction pressure. The external suction pressure generating means is connected to the plurality of vacuum passages 76 of the lower support 70 so that the suction pressure to each vacuum passage 76 can be controlled separately, and the suction pressure to all the vacuum passages 76 can be controlled simultaneously.

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 unit sheet portions 220 upward, so that the mask unit sheet portions 220 can be prevented from drooping downward during the bonding of the mask 100. Meanwhile, the lower supporter 70 and the stencil 50 press the edge portion of the mask 100 and the frame 200 (or the mask die sheet portions 220) in opposite directions to each other, and thus do not damage the alignment state of the mask 100 and maintain the alignment thereof.

Further, an adsorption force VS (or an adsorption pressure VS) is supplied from the adsorption portion 75 of the lower support 70, and as the adsorption force VS is applied to the mask 100 through the adsorption holes 229, the mask 100 is pulled to the adsorption portion 75 side (lower side). Thus, the interface between the mask 100 and the frame 200 (or the mask die portion 220) is in close contact.

Since the adsorption part 75 strongly pulls the mask 100, there is no fine gap between the interface of the mask 100 and the frame 200. As a result, since the mask 100 and the frame 200 (in the enlarged view of fig. 16, the first grid sheet portion 223) are in close contact, even if the laser light L is irradiated at any position of the welded portion, the weld bead WB can be easily generated between the mask 100 and the frame 200. The welding bead WB integrally connects the mask 100 and the frame 200, thereby having an advantage that welding can be stably performed.

In addition, the process of the mask 100 corresponding to the mask cell region CR of the frame 200, which does not apply any tensile force to the mask 100, may be completed only by attaching the mask 100 on the template 50 and loading the template 50 on the frame 200.

After the suction force VS of the suction portion 75 is applied, the mask 100 is irradiated with the laser L to bond the mask 100 to the frame 200 by laser welding. The welding portion of the mask laser-welded generates a welding bead WB, which may have the same material as the mask 100/frame 200 and be integrally connected with the mask 100/frame 200.

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

Referring to fig. 18, after the mask 100 is bonded 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 bonded to the frame 200, only the stencil 50 may be lifted. As an example, if heat ET higher than 85 to 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 template 50 becomes weak, so that the mask 100 may be separated from the template 50.

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 a non-stick process is performed on a part (central portion) of the mask 100 or the stencil 50, only the edge portion is adhered by the temporary adhesion portion 55. In addition, since the solvent penetrates the edge portion at the time of peeling, peeling can be achieved 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 process costs can be relatively reduced since a high-temperature heat treatment process is not required at the time of peeling, unlike the thermal peeling method.

Fig. 19 is a schematic view of a state in which the mask 100 is bonded to the frame 200 according to an embodiment of the present invention.

Referring to fig. 19, one mask 100 may be adhered to one cell region CR of the frame 200.

Since the mask unit sheet portions 220 of the frame 200 have a thin thickness, if the mask unit sheet portions 220 are adhered in a state where a tensile force is applied to the mask 100, the tensile force remaining in the mask 100 acts on the mask unit sheet portions 220 and the mask unit regions CR, and may cause deformation. Therefore, the mask 100 should be adhered to the mask unit sheet part 220 in a state where no tensile force is applied to the mask 100. The present invention can complete the process of corresponding the mask 100 to the mask cell region CR of the frame 200 without applying any tensile force to the mask 100 only by attaching the mask 100 on the template 50 and loading the template 50 on the frame 200. Thereby, it is possible to prevent the frame 200 (or the mask die portion 220) from being deformed by the tensile force applied to the mask 100 acting as a tensile force in reverse to the frame 200.

The conventional mask 10 of fig. 1 includes 6 cells C1-C6, which are long, whereas the mask 100 of the present invention includes one cell C, which is short, so that the degree of distortion of the pixel positioning accuracy becomes small. For example, assuming that the length of the mask 10 including the plurality of cells C1 to C6, … is 1m and a pixel positioning accuracy error of 10 μm occurs in the total length of 1m, the mask 100 of the present invention can 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, 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 therefore, a pixel positioning accuracy error of 1 μm occurs in the total length of 100mm, which has 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 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 (see fig. 2) in which a plurality of cells C (C1 to C6) are simultaneously corresponded 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 in correspondence with 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 in correspondence with 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, the product yield is low.

In addition, in (b) of fig. 11, 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 adhered to the frame 200, and if the mask 100 is separated from the stencil 50, the mask 100 will shrink to a predetermined degree.

If the template 50 is separated from the masks 100 after the respective masks 100 are adhered 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 will not be 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, so that an alignment error of the mask 100 (or the mask pattern P) can be minimized.

Fig. 20 is a schematic view of an OLED pixel deposition apparatus 1000 using a frame-integrated mask 100, 200 according to an embodiment of the present invention.

Referring to fig. 20, 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 masks 100 and 200 (or FMM) for depositing the organic material source 600 in different pixels may be disposed in close contact with or in close proximity to the target substrate 900. 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 adhesively 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 pixel positioning accuracy between the mask 100 and the adjacent mask 100 can be maintained to be 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 (20)

1. A method of manufacturing a frame-integrated mask, which integrates at least one mask with a frame for supporting the mask, wherein the method comprises the steps of:

(a) providing a frame having at least one mask cell region;

(b) providing a mask;

(c) corresponding the mask to the mask unit area of the frame; and

(d) irradiating laser to the welding portion of the mask and bonding the mask to the frame,

a plurality of adsorption holes are formed at a portion spaced apart from a corner of the frame having the mask unit region by a predetermined distance,

in the step (c), an adsorption force is applied to the mask contacted to the frame through the plurality of adsorption holes to closely attach the mask to the frame.

2. The method of manufacturing a frame-integrated type mask according to claim 1, wherein the step (b) comprises the steps of:

(b1) forming a mask metal film on at least one surface of the conductive substrate by electroforming;

(b2) separating the mask metal film from the conductive substrate;

(b3) bonding a mask metal film to a template having a temporary bonding portion formed on one surface thereof; and

(b4) a mask pattern is formed on the mask metal film to manufacture a mask.

3. The method of manufacturing a frame-integrated type mask according to claim 1, wherein the step (b) comprises the steps of:

(b1) providing a film-like mask metal film produced by rolling;

(b2) bonding a mask metal film to a template having a temporary bonding portion formed on one surface thereof;

(b3) a mask pattern is formed on the mask metal film to manufacture a mask.

4. The method of manufacturing a frame integrated type mask according to claim 2 or 3, wherein the step (c) is a step of loading the template onto the frame and corresponding the mask to the mask cell area of the frame.

5. The method of manufacturing a frame-integrated mask according to claim 1, wherein in the step (c), a lower support including an adsorption portion for generating a suction pressure is disposed at a lower portion of the frame.

6. The method of manufacturing a frame-integrated mask according to claim 5, wherein the lower supporter presses an opposite surface of a mask unit region for loading the mask.

7. The method of manufacturing a frame integrated type mask according to claim 1, wherein the adsorption hole is formed at a portion not overlapping with the welding portion of the mask.

8. The method for manufacturing a frame-integrated mask according to claim 2, wherein the conductive substrate is a wafer,

a process of heat-treating the mask metal film is further performed between the step (b1) and the step (b 2).

9. The method of manufacturing a frame integrated type mask of claim 3, further comprising a step for reducing a thickness of the mask metal film adhered on the template between the step (b2) and the step (b3),

the thickness reduction of the mask metal film is performed by any one of chemical mechanical polishing, chemical wet etching, and dry etching.

10. The method of manufacturing a frame-integrated mask according to claim 2 or 3, wherein the temporary bonding portion is an adhesive or a bonding sheet that is separable by heating, an adhesive or a bonding sheet that is separable by irradiation of UV.

11. The method of manufacturing a frame integrated type mask according to claim 2 or 3, wherein the step of forming a mask pattern on the mask metal film to manufacture the mask comprises:

(1) forming a patterned insulating portion on the mask metal film;

(2) etching the exposed portions of the mask metal film between the insulating portions to form mask patterns; and

(3) the insulating part is removed.

12. The method of manufacturing a frame-integrated mask according to claim 2 or 3, wherein the template is made of any one of a wafer, glass, silica, pyrex, quartz, alumina, borosilicate glass, and zirconia.

13. The method of manufacturing a frame-integrated mask according to claim 4, wherein the laser irradiated from the upper portion of the mask is irradiated to the welding portion of the mask through the laser passage hole.

14. The method of manufacturing a frame integrated mask according to claim 4, further comprising a step of separating the mask from the template by any one of heating, chemical treatment, and ultrasonic wave application to the temporary bonding portion after the step (d).

15. The method of manufacturing a frame integrated type mask according to claim 1, wherein the frame includes an edge frame portion and a mask cell sheet portion,

the mask unit sheet part includes:

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, intersecting the first grid sheet part, and having both ends connected to the edge sheet part.

16. The method of manufacturing a frame-integrated mask according to claim 1, wherein the mask and the frame are made of any one of invar, super-invar, nickel, and nickel-cobalt.

17. A frame for use in a frame-integrated mask in which a plurality of masks and a frame for supporting the masks are integrally formed, the frame comprising:

an edge frame portion including a hollow region; and

a mask unit sheet portion having a plurality of mask unit regions in at least one of a first direction and a second direction perpendicular to the first direction and connected to the edge frame portion,

the mask unit sheet portion has a plurality of suction holes formed therein.

18. The frame according to claim 17, wherein a plurality of adsorption holes are formed at a portion spaced apart from a corner of the frame having the mask unit region by a predetermined distance,

the suction holes are formed at portions not overlapping with the welding portions of the mask.

19. The frame according to claim 17, wherein the lower portion of the frame is further provided with a lower support including a suction portion for generating suction pressure.

20. The frame according to claim 19, wherein the lower supporter is formed thereon with at least one vacuum passage for transmitting suction pressure generated by the external suction pressure generating means to the suction part.

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