Method for manufacturing deposition mask frame assembly for display panel

Abstract

To prevent wrinkles of a vapor deposition mask having a size equal to or more than a medium size from occurring due to drawing to manufacture an elaborate and high quality vapor deposition mask frame assembly.SOLUTION: A method for manufacturing a vapor deposition mask frame assembly for display panels comprises: welding a support stick mask and gap stick mask provided on a frame to the frame; drawing the vapor deposition stick mask in the X axis direction along the longitudinal direction; welding and integrating the frame of the vapor deposition stick mask in the Y axis direction in an adsorbed and drawn state to the frame; and preventing wrinkles of the vapor deposition mask from occurring due to the drawing to manufacture an elaborate and high quality vapor deposition mask frame assembly.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing an evaporation mask frame assembly for a display panel, and more particularly to a technique for manufacturing a mask frame assembly by stretching and welding a mask. [Background technology]

[0002] Among display devices, OLED display panels using organic light emitting diodes (OLEDs) have the advantages of a wide viewing angle, excellent contrast, and fast response speed. For this reason, the use of OLEDs is gradually expanding.

[0003] The electrodes and intermediate layers, including the light-emitting layer, of these organic light-emitting diodes (OLEDs) can be formed by various methods, one of which is the deposition method.

[0004] To manufacture small and medium-sized OLED display panels, the deposition process of organic and inorganic materials is used to create RGB pixels in the OLED manufacturing process. That is, a fine metal mask (FMM) with the same pattern as the thin film formed on the TFT glass (Thin Film Transistor Glass) is aligned, and a thin virgin material is deposited to form a thin film with the desired pattern. This deposition process involves heating the organic material in a deposition source located at the bottom of the chamber, sublimating the heated organic material, and depositing it on the TFT glass through a mask located at the top.

[0005] Such fine metal masks (FMMs) are also called deposition stick masks because they have a stick shape as a whole. In general, deposition stick masks are pulled at one end and the other end simultaneously, and the deposition stick mask is laser-welded to a mask frame to manufacture a deposition mask frame assembly.

[0006] Deposition stick masks are widely used to manufacture deposition mask frame assemblies as they enable mass production of display panels. Deposition mask frame assemblies are used to produce relatively small display panels such as smartphones, but recently there has been a need to develop stick mask frame assemblies that can be applied to medium-sized or larger display panels such as tablet PCs and notebook computers.

[0007] Fig. 1 is a diagram illustrating a vapor deposition stick mask, in which (a) in Fig. 1 is a diagram showing the top surface of the vapor deposition stick mask, and (b) in Fig. 1 is a diagram showing a cross section taken along line A-A' in (a) in Fig. 1.

[0008] As shown in FIG. 1(a), a deposition stick mask 100, which is usually called a fine metal mask (FMM), includes a structural stick mask 110 and a plurality of cell unit masks 120, and extends in the longitudinal direction.

[0009] The structural stick mask 110 is composed of a frame 111 and a rib 112, and a number of deposition pattern holes P are formed in a plurality of cell unit masks 120. Several cell unit masks may be present in one structural stick mask 110. Hundreds of thousands to millions of deposition pattern holes P may be formed in one cell unit mask. The frame 111 may further be provided with a plurality of skirts 113 symmetrically at one end and the other end, which may function as a gripping area. Grippers (not shown) may grip the skirts and easily perform tension Tx in the X-axis direction along the longitudinal direction. One gripper is disposed for each skirt to grip it, and when eight skirts are provided as in FIG. 1(a), the eight grippers perform tension simultaneously.

[0010] The structural stick mask 110 may have a thickness of 100 μm to 200 μm, a length of 1 m or more, and a width of several tens of centimeters, and the cell unit mask 120 may have a thickness of 10 μm to 20 μm. The cell unit mask 120 may be seamlessly integrated with the structural stick mask 110, or may be manufactured separately and joined by welding, so that seams may exist.

[0011] In addition, the structural stick mask 110 further includes ribs 112, which are provided between the cell unit masks 120 and refer to regions where deposition pattern holes are not formed.

[0012] However, when a large deposition stick mask is pulled simultaneously by multiple grippers, the pulling force is not uniformly applied to the deposition stick mask, which causes wrinkles and shrinks in the Y-axis direction (arrow direction). For example, when four skirts are provided at one end and four grippers grip it, three wrinkles W1, W2, and W3 may occur as shown in the figure. Since the shrinkage force is larger in the middle region of the deposition stick mask than in the end regions, the size and depth of the wrinkles may also be larger in the middle region of the deposition stick mask.

[0013] In addition, as the size of the deposition stick mask increases, the ribs become longer in the Y-axis direction and heavier, which can cause the ribs to sag due to gravity.

[0014] As shown in Figure 1(b), the deposition stick mask shrinks in the Y-axis direction (arrow direction), and three wrinkles W1, W2, and W3 occur. This increases the shadow effect and causes a problem of degraded quality of the deposition mask frame assembly.

[0015] Furthermore, the larger the size of the deposition stick mask, the more grippers it will need to pull, which will increase the number of wrinkles and further exacerbate the quality degradation problem.

[0016] A Korean registered patent (registration number: 10-2193044, "Metal mask manufacturing system and method") discloses a technology in which the frames on two or more sides of a tension mask are tensioned via multiple clampers and fixed to the mask frame in a flat state, but does not disclose a method of suction tension in the Y-axis direction to prevent wrinkles from occurring in stick-type masks. Summary of the Invention [Problem to be solved by the invention]

[0017] The present invention relates to a method for manufacturing a deposition mask frame assembly, and an object of the present invention is to manufacture an accurate and high-quality deposition mask frame assembly by preventing wrinkles caused by tension on a medium-sized or larger deposition mask. [Means for solving the problem]

[0018] According to one embodiment to achieve the above object, a method for manufacturing a deposition mask frame assembly using a deposition stick mask including a structural stick mask having a frame and ribs and a plurality of cell unit masks in which a number of deposition pattern holes are formed includes the steps of: providing a rectangular frame having a hollow portion; providing a support stick mask on the frame, and welding the support stick mask to the frame while being stretched in the Y-axis direction along its longitudinal direction; providing a gap stick mask on the frame, and welding the gap stick mask to the frame while being stretched in the X-axis direction along its longitudinal direction; and providing a deposition stick mask on the frame, and welding the frame to the frame while the deposition stick mask is stretched in the X-axis direction along its longitudinal direction and is simultaneously adsorbed and stretched in the Y-axis direction. This prevents wrinkles from occurring due to tension, and allows the manufacture of an elaborate and high-quality deposition mask frame assembly. Effect of the Invention

[0019] The present invention can prevent wrinkles caused by tension on a medium or larger sized deposition stick mask, and can manufacture an elaborate and high quality deposition mask frame assembly.

[0020] In addition, by manufacturing a deposition mask frame assembly using the support stick mask and the gap stick mask, the deposition masks can be stably fixed and gaps between the deposition masks can be covered.

[0021] In addition, there is no need to form a separate skirt on the vapor deposition stick mask, and damage to the vapor deposition stick mask can be prevented.

[0022] In addition, laser welding is performed on the bottom surface to prevent lifting or gaps between the TFT glass and the cell unit mask during the deposition process. [Brief description of the drawings]

[0023] [Figure 1]1 is a diagram illustrating a vapor deposition stick mask.

[0024] [Diagram 2] 1 is a diagram illustrating a method of manufacturing a deposition mask frame assembly according to an embodiment.

[0025] [Diagram 3] 1 is a diagram illustrating a method of welding a support stick mask to a frame according to an embodiment.

[0026] [Figure 4] 1 is a diagram illustrating a method of welding a gap stick mask to a frame according to an embodiment.

[0027] [Diagram 5] 1 is a diagram illustrating a method of mounting a deposition stick mask on a frame according to an embodiment.

[0028] [Figure 6] 1 is a diagram illustrating a method for pulling a deposition stick mask according to an embodiment.

[0029] [Figure 7] 1 is a diagram illustrating a method for welding overlapping regions according to an embodiment.

[0030] [Figure 8] 11 is a diagram illustrating a method for welding overlapping regions of a deposition stick mask, a gap stick mask, and a support stick mask according to another embodiment.

[0031] [Figure 9] 9 is a diagram illustrating an opening of the support stick mask according to the embodiment of FIG. 8.

[0032] [Figure 10] 1 is a view showing a deposition mask frame assembly in which welding has been completed;

[0033] [Figure 11] 1 is a diagram showing a trimmed deposition mask frame assembly.

[0034] [Figure 12] 12 is a diagram showing the deposition mask frame assembly of FIG. 11 to which a cell unit mask is not yet attached.

[0035] [Figure 13] 13 is a diagram illustrating a method of welding a cell unit mask onto the structural stick mask of FIG. 12. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] Hereinafter, the present invention will be described in detail through preferred embodiments described with reference to the accompanying drawings so that those skilled in the art can easily understand and reproduce the present invention. In the description of the present invention, if a detailed description of related known functions or configurations is deemed to unnecessarily obscure the gist of the embodiments of the present invention, the detailed description will be omitted. In the present invention, the terms used throughout the specification are defined in consideration of the functions in the embodiments of the present invention, and are matters that can be sufficiently changed according to the intentions, practices, etc. of the user or operator, so the definitions of these terms should be based on the overall content of this specification.

[0037] In addition, the above-mentioned and additional aspects of the invention will become clear through the embodiments described below. In this specification, even if the aspects and the configurations of the embodiments described selectively are shown as a single integrated configuration in the drawings, they can be freely combined with each other unless otherwise specified, unless it is obvious that there is a technical contradiction to a person skilled in the art.

[0038] Therefore, it should be understood that the embodiment described in this specification and the configurations shown in the drawings are merely the most preferred embodiment of the present invention and do not represent the entire technical idea of ​​the present invention, and therefore there may be various equivalents and modifications that can replace them at the time of this application.

[0039] 2 is a diagram illustrating a method for manufacturing a deposition mask frame assembly according to an embodiment. As shown in the figure, a method for manufacturing a deposition mask frame assembly using a structural stick mask having a frame and ribs and a deposition stick mask including a plurality of cell unit masks in which a plurality of deposition pattern holes are formed includes the following operations. That is, the method for manufacturing a deposition mask frame assembly includes a step S100 in which a rectangular frame having a hollow portion is provided, a step S200 in which a support stick mask is provided on the frame and welded to the frame while being stretched in the Y-axis direction along the longitudinal direction, a step S300 in which a gap stick mask is provided on the frame and welded to the frame while being stretched in the X-axis direction along the longitudinal direction, and a step S400 in which a deposition stick mask is provided on the frame and welded to the frame while being stretched in the X-axis direction along the longitudinal direction and simultaneously suction-stretched in the Y-axis direction.

[0040] FIG. 3 is a diagram illustrating a method of welding a support stick mask to a frame according to an embodiment. As shown in the figure, a frame 200 is provided. The frame 200 may have a rectangular shape with a central opening. The frame 200 may be configured with long and short sides as a rectangle. A support stick mask 300 is provided on the frame, and the support stick mask may be welded to the frame while being pulled in the Y-axis direction along the longitudinal direction. There may be at least two support stick masks 300, and the support stick masks may be welded to the short sides of the frame 200 in a flat state by applying a tension of Ty by a gripper. The support stick mask 300 supports another stick mask located on the top of the support stick mask, and can prevent drooping of the other stick mask. The welding may be optical welding, particularly laser beam welding, and may be performed by irradiating a laser beam onto the upper surface of the support stick mask.

[0041] 4 is a diagram illustrating a method of welding a gap stick mask to a frame according to an embodiment. As shown in the figure, a gap stick mask 400 is provided on a frame, and the gap stick mask can be welded to the frame 200 in a state where the gap stick mask is stretched in the X-axis direction along the longitudinal direction. There can be at least two gap stick masks 400, and the gap stick masks 400 can be welded to the long sides of the frame 200 in a flat state with a tension force of Tx applied. Welding can be performed by irradiating a laser onto the upper surface of the gap stick mask.

[0042] The gap stick mask may be narrower than the support stick mask and may be shorter in length. The gap stick mask and the support stick mask may be formed with separate skirts, but not as shown, and may be gripped by one gripper at one end. The gap stick mask and the support stick mask may each be pulled in both directions by the grippers.

[0043] According to an embodiment, the method for manufacturing the deposition mask frame assembly may further include a step of welding the overlapping area of ​​the support stick mask 300 and the gap stick mask 400 to fix the gap stick mask to the support stick mask, thereby maintaining the gap stick mask in close contact with the support stick mask.

[0044] 5 is a diagram illustrating a method of mounting a deposition stick mask on a frame according to an embodiment. As shown in the figure, a deposition stick mask 100 is mounted on a frame 200. The deposition stick mask 100 may be disposed such that the rib 112 is positioned on the support stick mask 300 based on the X axis, and the frame 111 is positioned on the support frame 200 or the gap stick mask 400 based on the Y axis. When disposed in this manner, a region WZ1 where the rib 112 and the support stick mask 300 overlap is formed, and at the same time, a region WZ2 where the support stick mask 300, the gap stick mask 400, and the frame 111 overlap may be formed. WZ1 and WZ2 may function as welding zones.

[0045] The gap stick mask 400 may be disposed on the upper side or the lower side of the deposition stick mask 100 as shown in the figure. In order to be disposed on the lower side, the gap stick mask 400 may be welded after the deposition stick mask 100 is welded.

[0046] 6 is a diagram illustrating a method for stretching a deposition stick mask according to an embodiment, in which (a) of FIG. 6 is a diagram illustrating a top surface of a stretched deposition stick mask, and (b) of FIG. 6 is a diagram illustrating a cross section taken along line A-A' of (a) of FIG. 6.

[0047] As shown in FIG. 6(a), a tensile force Tx is applied to the deposition stick mask in the X-axis direction along the longitudinal direction, and at the same time, an adsorption tensile force Ty is applied to the deposition stick mask in the Y-axis direction. Ty is preferably smaller than Tx (Ty <Tx)。

[0048] Adhesion tension can be performed by tensioning the frame region TZ1 located at the edge and the frame region TZ2 adjacent to the rib in the Y-axis direction while being adsorbed. As a result, as shown in FIG. 6B, no wrinkles are generated in the wrinkle-vulnerable rib 112, and the shape and position of the pattern hole of the cell unit mask can be maintained.

[0049] The suction pulling can be performed by a vacuum method or an electrostatic method. This has the advantage that there is no need to form an additional skirt on the frame 111 and the evaporation stick mask is not pulled using a gripper, which prevents damage to the evaporation stick mask. A separate suction pulling machine 2000 can be introduced for the suction pulling.

[0050] The frame 111 may include a skirt 113. The skirt 113 is an area that the gripper grips and is not a required component.

[0051] 7 is a diagram illustrating a method for welding overlapping regions according to an embodiment of the present invention, in which (a) of FIG 7 is a diagram illustrating a method for welding overlapping regions WZ1 of the deposition stick mask 100 and the support stick mask 300, and (b) of FIG 7 is a diagram illustrating a method for welding overlapping regions WZ2 of the deposition stick mask 100, the gap stick mask 400, and the support stick mask 300.

[0052] 7(a), the method for manufacturing the deposition mask frame assembly may further include a step of arranging the deposition stick mask 100 so that the rib 112 is positioned on the support stick mask 300, and welding the overlapping area WZ1 (dotted line) of the rib and the support stick mask to fix the deposition stick mask to the support stick mask. The rib and the support stick mask are fused and fixed to each other at a joint point J.

[0053] Furthermore, a laser may be irradiated onto the "Lower Surface" of the support stick mask to weld the area WZ1 where the rib and the support stick mask overlap. This may result in a bar (welding protrusion, Bur) being generated on the lower surface of the support stick mask 300.

[0054] Also, as shown in FIG. 7B, the method for manufacturing the deposition mask frame assembly may further include a step of positioning a part of the frame on the gap stick mask, and welding an overlapping region WZ2 (dotted line) of the support stick mask 300, the gap stick mask 400, and the frame 111 of the deposition stick mask 100. The welding may be welding using a laser, in which the laser is irradiated to the "lower surface" of the support stick mask to bond the gap stick mask and the support stick mask at a bonding point J1, and the laser is irradiated to the "upper surface" of the deposition stick mask to bond the gap stick mask and the deposition stick mask, and the gap stick mask and the deposition stick mask are melted and bonded at a bonding point J2. As a result, a bar is generated on the upper surface of the deposition stick mask and the lower surface of the support stick mask. The upper surface of the deposition stick mask is the surface that comes into close contact with the TFT glass during the deposition process.

[0055] Fig. 8 is a diagram illustrating a method for welding overlapping regions of a deposition stick mask, a gap stick mask, and a support stick mask according to another embodiment. Fig. 8 is an embodiment that improves the problem of the embodiment of Fig. 7(b), and is related to preventing the generation of burrs on the upper surface of the deposition stick mask.

[0056] In the manufacturing method of the deposition mask frame assembly, the support stick mask has an opening, and the laser is irradiated to the lower opening of the support stick mask and the area outside the lower opening, and the area WZ2 where the support stick mask, the gap stick mask, and the frame overlap can be welded. As a result, the bar is formed only on the lower surfaces of the support stick mask and the gap stick mask, and no gap occurs when the TFT glass and the hybrid stick mask are in close contact during the deposition process, and the shadow effect can be reduced by tightly adhering.

[0057] According to an embodiment, in order to weld the overlapped regions of the deposition stick mask, the gap stick mask, and the support stick mask, a bar can push up the lower surface of the support stick mask to a certain height, thereby temporarily bringing the deposition stick mask, the gap stick mask, and the support stick mask into close contact with each other to achieve close contact welding.

[0058] Fig. 9 is a diagram illustrating an opening of the support stick mask according to the embodiment of Fig. 8. As shown in the figure, the support stick mask 300 may have an opening penetrating therethrough, which allows the embodiment of Fig. 8 to be performed. The openings may be formed in a plurality of pieces, and may be formed in the region WZ2 where the support stick mask, the gap stick mask, and the frame overlap.

[0059] 10 is a diagram showing a deposition mask frame assembly in which welding has been completed. As shown in the figure, the support stick mask 300, the gap stick mask 400, and the deposition stick mask 100 were welded according to the embodiments of FIGS. 4, 7, and 8 to manufacture an assembly in which each stick mask and the frame are integrated. The region WZ1 (dotted line) where the rib and the support stick mask overlap was welded according to the embodiment of FIG. 7(a), and the region WZ2 (dotted line) where the frame 111 of the support stick mask 300, the gap stick mask 400, and the deposition stick mask 100 overlap was welded according to the embodiment of FIG. 8.

[0060] The deposition stick masks 100 are welded to each other at a distance of a length L to avoid interference between the deposition stick masks. By forming the distance, the gap mask 400 can prevent the problem of organic leakage during the deposition process.

[0061] 11 is a diagram showing a trimmed deposition mask frame assembly. As shown in the figure, the method for manufacturing the deposition mask frame assembly 1000 may further include a step of cutting or trimming parts of the support stick mask 300, the gap stick mask 400, and the deposition stick mask 100 located outside the frame 200. The deposition mask frame assembly 1000 may be completed by cutting.

[0062] For the deposition process, the deposition mask frame assembly 1000 is used such that a TFT glass (not shown) is closely fitted to a hollow region of the frame 200 and an organic material source is disposed below the deposition mask frame assembly 1000, thereby performing deposition.

[0063] FIG. 12 is a diagram showing the deposition mask frame assembly of FIG. 11 without the cell unit mask attached, and FIG. 13 is a diagram explaining a method of welding the cell unit mask 120 onto the structural stick mask 110.

[0064] As shown in Fig. 12, a method for manufacturing a deposition mask frame assembly according to an embodiment can be performed by the method described in Fig. 5 to Fig. 10 using a structural stick mask 110 to which a cell unit mask is not attached after the steps of Fig. 3 and Fig. 4. The structural stick mask 110 may have an opening.

[0065] 13, a step may be included in which a plurality of cell unit masks 120 are provided on the structural stick mask 110 (particularly, at the openings), and the cell unit masks are fixed to the structural stick mask through laser welding. As a result, since the assembly process of the cell unit masks is a subsequent process, there is an advantage in that the positional variation of the deposition pattern holes P in the manufacturing process of the deposition mask frame assembly can be minimized. Through this process, the deposition mask frame assembly of FIG. 11 can be completed.

[0066] According to an embodiment, a laser can be irradiated to the "bottom surface" of the structural stick mask 110 to perform welding. As a result, a bur is formed on the bottom surface of the structural stick mask, and no gap occurs when the TFT glass and the hybrid stick mask are attached to each other during the deposition process, resulting in tight adhesion and reducing the shadow effect. [Explanation of symbols]

[0067] 100: Vapor deposition stick mask 110: Structural stick mask 111: Frame 112: Rib 113: Skirt 120: Cell-by-cell mask 200: Frame 300: Support stick mask 400: Gap Stick Mask 1000: Deposition mask frame assembly 2000: Suction puller

Claims

1. A method for manufacturing a deposition mask frame assembly using a deposition stick mask including a structural stick mask having a frame and a rib, and a plurality of cell unit masks, each of which is separate from the structural stick mask and has a plurality of deposition pattern holes formed therein, comprising: Providing a frame having a rectangular shape with a hollow portion formed therein; A support stick mask is provided on a frame, and the support stick mask is welded to the frame in a state where the support stick mask is tensioned in the Y-axis direction along the longitudinal direction; A gap stick mask is provided on a frame, and the gap stick mask is welded to the frame while being tensioned in the X-axis direction along the longitudinal direction; a vapor deposition stick mask is provided on a frame, the vapor deposition stick mask is pulled in the X-axis direction along the longitudinal direction, and the frame is welded to the frame while being pulled by suction in the Y-axis direction at the same time; irradiating a laser onto the lower opening and an area outside the lower opening of the support stick mask, thereby welding the overlapping areas of the support stick mask, the gap stick mask, and the frame; Including, The suction tensioning is performed by pulling an area of ​​the deposition stick mask that does not overlap with the plurality of cell unit masks in the Y-axis direction in a state where the area is suctioned by an suction tensioning machine in the Y-axis direction.

2. 2 . The method of claim 1 , further comprising the step of welding an overlapping area of ​​the support stick mask and the gap stick mask to fix the gap stick mask to the support stick mask.

3. The vapor deposition stick mask is The method for manufacturing an evaporation mask frame assembly according to claim 2 , further comprising the steps of: arranging the rib to be positioned on the support stick mask; welding an overlapping area WZ1 of the rib and the support stick mask; and fixing the evaporation stick mask to the support stick mask.

4. The method for manufacturing a deposition mask frame assembly according to claim 3 , wherein a laser is irradiated onto a lower surface of a support stick mask, and a region WZ1 where the rib and the support stick mask overlap is welded.

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