KR101659961B1 - Grid pattern sheet for thin film deposition, manufacturing apparatus of mask assembly, and mask assembly therefrom - Google Patents

Abstract

The present invention relates to a grid pattern sheet, an apparatus and a method of manufacturing a mask assembly using the same, and a mask assembly. The grid pattern sheet according to the present invention is bonded to the mask frame of a mask assembly for the thin film processes under a preset pressure, and comprises unit patterns for thin film processes. The grid pattern sheet includes a virtual lattice which includes grids which are respectively extended two directions which are orthogonal to each other on the surface of the pattern sheet, and are symmetrical to each other with regard to the center axes of the pattern sheet which are orthogonal to each other, and protrusion ends which are protruded to opposite directions to both end parts of each of the grids of the virtual lattice. So, an increase of the shadow phenomenon can be minimized.

Description

Technical Field [0001] The present invention relates to a large pattern sheet, a method of manufacturing a mask assembly using the same, a manufacturing apparatus, and a mask assembly,

The present invention relates to a mask assembly for a thin film process, and more particularly to a technique for manufacturing a mask assembly for a thin film process in which a thin film pattern sheet having a predetermined mask pattern is bonded to a mask frame.

BACKGROUND ART [0002] Organic light-emitting diodes (OLEDs) that have been widely manufactured are widely used as display devices for televisions, personal computers (PCs), tablet PCs, smart phones, smart watches and vehicle instrument panels. OLEDs are thin-film light-emitting diodes whose light-emitting layers are organic compounds. There is a need for a thin film process in which a plurality of thin film layers such as an electrode layer, an organic light emitting layer, and an insulating film are laminated and patterned on a wafer substrate during OLED manufacturing. The thin film process uses a mask assembly having a corresponding pattern and includes, for example, chemical vapor deposition (CVD), sputtering, ion plating, vacuum evaporation, and the like do.

The mask assembly used in the thin film process has a structure in which a relatively thin sheet of thin film, a support strip, and / or a stick or the like is bonded on a mask frame having a relatively strong structure. In the case of the mask frame, the frame structure is a window frame or a door frame having a thickness of about 5 to 80 mm, and functions to stably maintain the shape of the mask assembly. The mask sheet or stick is formed on a thin metal sheet or strip having a thickness of about 0.01 to 5.00 mm to form a predetermined pattern to be used in deposition. In general, a mask sheet having a pattern and a mask assembly such as a mask stick and a mask frame are manufactured using a metal having a very small coefficient of thermal expansion such as an invar alloy (Invar-36 Alloy). Further, when the precision of the pattern is not required to a great extent, the mask frame may be made of stainless steel which is resistant to heat, such as SUS420 for cost reduction.

In general, the thin film process in which the mask assembly is used is carried out at a high temperature. In accordance with current OLED manufacturing processes, thin film processes for at least several thousand substrates are typically repeated continuously for one mask assembly. As the thin film process proceeds, the mask assembly is constantly exposed to high temperatures, and therefore, the mask pattern is gradually deformed by heat. This is one of the main causes of the shadow phenomenon adversely affecting the yield of the whole process. Also, since dozens of mask assemblies such as an open mask and an FM (fine metal) mask for RGB formation are used corresponding to each substrate for manufacturing an OLED in an OLED manufacturing process, shadow phenomena due to thermal deformation occurring in each mask assembly are tens of times And the yield is further lowered.

In recent years, the resolution of OLEDs has increased not only in HD (High Definition), FHD (Full HD) and UHD (Ultra HD) but also in display devices of portable devices such as foldable display devices It is expected to increase sharply to about 10 inches. Therefore, there is a desperate need to increase the precision of the mask assembly by reducing the thermal deformation of the mask assembly, thus requiring that the patterns formed in the mask assembly become finer and more precise.

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Korean Patent Publication No. 10-2015-0071321 (published on June 26, 2016) Korean Patent Laid-Open No. 10-2014-0000737 (published on April 1, 2014) Korean Patent Publication No. 10-2012-0079725 (published on July 13, 2012) Korean Patent Publication No. 10-2011-0069466 (published on June 23, 2011) Korean Registered Patent No. 10-0658762 (Registered on December 11, 2006)

In the process of finding a technique for reducing the thermal deformation of a mask assembly, the present inventor has found that, in the process of finding a technique for reducing the thermal deformation of a mask assembly, a sheet having a conventional pattern or a plurality of strip / stick sets (hereinafter referred to as " patterned sheet ) 'Is stretched so as to maintain a constant tensile force, and is then bonded onto the mask frame. Further, stresses generated by heat are applied to the pattern sheet which is strained by this tensile force, .

Generally, the pattern sheet is supported by being bonded to the mask frame at its edge. Therefore, the central portion of the pattern sheet, which is not supported by the mask frame, is lowered by gravity. In order to solve this problem, the pattern sheet is generally tensioned at the edges thereof by being stretched and joined on the mask frame, whereby the tension is maintained in the pattern sheet in the direction perpendicular to each other on the horizontal plane. Further, in order to bring the pattern sheet into close contact with the substrate, a magnetic force for pulling the pattern sheet toward the substrate is used. Accordingly, the pattern sheet of the mask assembly can be brought into close contact with the surface of the substrate on which the thin film is to be formed, so that a precise patterning process can be performed.

However, as the thin film process lasts for a long time, the mask assembly experiences thermal deformation. Observing the deformation pattern generated by this heat, the pattern sheet on the plane defined by the upper surface of the mask frame exhibits an unusual deformation pattern in which it is bent up and down as a whole and ruggedly deformed. This deformation pattern generates additional stress in a direction in which the already stretched pattern sheet itself is deteriorated by heat and is further stretched while the thermal stress generated in the mask frame is transmitted to the pattern sheet to compress the pattern sheet toward the center It is possible to predict that the stress is applied in the direction of the direction. As a result, the pattern sheet undergoes pressure in opposite directions from its edges, resulting in a physical deformation in the pattern sheet. As a result, it can be seen that a specific deformation pattern is formed, which is unevenly deformed as a whole.

Therefore, in order to solve the problem of thermal deformation of the mask assembly according to the elapse of time of the thin film process, the present inventor has found that when the pattern sheet is adhered to the mask frame, if thermal stresses generated in the mask frame and the pattern sheet are transmitted to each other It has been realized that the thermal deformation of the pattern sheet can be greatly reduced and therefore the increase of the shadow phenomenon over time of the thin film process can be minimized.

Further, if the tensile force applied to maintain the tensile force on the pattern sheet can be reduced, the inventor can absorb most of the stress generated by the heat even if the pattern sheet is continuously exposed to a high temperature, I can do it.

The present invention is based on the above-described realization of the inventor of the present invention. In a mask assembly used in a thin film process, a plurality of ribs, which are, for example, transverse in two mutually orthogonal directions, are defined as main planes of the pattern sheet, The tensile force for imparting tension to the pattern sheet can be reduced by protruding the end from the edge of the pattern sheet and by stretching each of these ribs and joining both ends thereof to the mask frame, A new large-sized mask sheet capable of minimizing thermal stress transfer between a pattern sheet and a mask frame caused by a material or due to different shapes, a method of manufacturing a mask assembly using the same, a manufacturing apparatus, and a mask assembly .

Further, in the present invention, the pattern sheet is defined as a virtual lattice region composed of a plurality of ribs defined in two directions orthogonal to each other, and the solid region of the virtual lattice includes a through hole in which the thickness of the pattern sheet is entirely etched and / A buffer structure such as a partially etched groove is formed so as to increase the surface area of the pattern sheet itself and to minimize the contact area between the pattern sheet and the other flat plate structure, A mask assembly, a manufacturing apparatus, and a mask assembly using the same.

This object is achieved by a large pattern sheet provided according to the present invention, a method of manufacturing a mask assembly using the same, a manufacturing apparatus, and a mask assembly manufactured using the same.

A large pattern sheet provided according to an aspect of the present invention is a pattern sheet which is joined to a mask frame of a mask assembly for thin film process with a predetermined tensile force applied thereto and has a plurality of unit patterns for thin film process, A virtual grid defined by a plurality of ribs each extending in two mutually orthogonal directions defined by the surface of the pattern sheet and symmetrically arranged with respect to two mutually orthogonal center axes of the pattern sheet; And a plurality of protruding ends protruding in opposite directions at opposite ends of each of the ribs of the virtual lattice.

The plurality of protruding ends having the same width and length at both ends of each of the ribs; And can be arranged symmetrically with respect to two mutually orthogonal center axes of the pattern sheet.

An area of each of the plurality of protruding ends includes: a joint area bonded to the mask frame; And a bridge region connecting the junction region and the virtual lattice and not joined to the mask frame.

Here, the junction region has a constant width W, and the width of the bridge region may gradually increase from the width of the junction region to the virtual lattice gradually or stepwise.

The area of the rib excluding the projecting ends may be defined by an area other than the plurality of unit patterns for thin film processing among the pattern sheet areas. Alternatively or additionally, the region of the rib excluding the protruding ends may be defined by partially including the plurality of unit pattern regions for thin film processing among the pattern sheet regions.

The area of the ribs excluding the projecting ends may be formed of a thermal buffer structure including at least one of a through structure in which the pattern sheet thickness is completely removed and a groove structure in which the pattern sheet thickness is partially removed.

The guard strip may be further provided on the outside of the plurality of protruding ends and connected to the inner ends of the ends of the protruding ends and surrounding the area of the pattern sheet.

A cut line may be formed at a portion connected to the guard strip and the plurality of protruding ends so that the pattern sheet is at least partially removed in order to facilitate cutting.

According to another aspect of the present invention, there is provided a method of manufacturing a mask assembly using a large-sized pattern sheet, the mask assembly comprising a mask frame of a mask assembly for a thin film process, A plurality of ribs each extending in two mutually orthogonal directions defined on a surface of the pattern sheet and symmetrically arranged with respect to two mutually orthogonal center axes of the pattern sheet, Virtual grid; And a pattern sheet producing step of fabricating a patterned large pattern sheet having a plurality of protruding ends protruding in opposite directions at opposite ends of each of the ribs of the virtual grid; A stretching step of stretching each of the ribs of the virtual lattice in mutually opposing directions using protrusions formed on the pattern sheet; And joining at least a part of each of the projecting ends to the mask frame in the stretched state.

The joining step may include joining only a part of the protruding end to the mask frame in a state in which the edge line of the pattern sheet protruding from the protruding end is disposed at a predetermined distance from the inner surface of the mask frame, can do.

The mask frame has a rib groove for allowing protruding ends of the pattern sheet to be inserted and joined. In the joining step, protruding ends of the pattern sheet may be inserted into the rib groove and then joined.

Further comprising a guard strip connected to the ends of the plurality of protruding ends inside the plurality of protruding ends and surrounding an area of the pattern sheet, wherein, in the tensioning step, Each of the ribs between the protruding ends may be pulled in both directions opposite to each other, and the guard strip may be cut after the protruding ends are joined in the joining step.

According to still another aspect of the present invention, there is provided an apparatus for manufacturing a mask assembly using a large pattern sheet, the apparatus comprising: a mask frame of a mask assembly for a thin film process, A pattern sheet, comprising a plurality of ribs each extending in two mutually orthogonal directions defined on the surface of the pattern sheet and symmetrically arranged with respect to two mutually orthogonal center axes of the pattern sheet A virtual grid; And a plurality of protruding ends protruding in opposite directions at opposite ends of each of the ribs of the virtual lattice, wherein each of the ribs of the virtual lattice is tensioned in both directions facing each other using the protruding ends, ; And a joint portion joining at least a part of the regions of each of the projecting ends to the mask frame in the stretched state.

The joining portion joins only a part of the protruding end on the mask frame in a state in which the edge line of the pattern sheet protruding from the protruding end is disposed at a predetermined distance from the inner surface of the mask frame .

In addition, a mask assembly including a large pattern sheet provided according to another aspect of the present invention includes a plurality of unit patterns for thin film processing, which are bonded to a mask frame of a mask assembly for thin film process with a predetermined tensile force applied thereto Wherein the plurality of ribs extend in two mutually orthogonal directions defined by the surface of the pattern sheet and are arranged symmetrically with respect to two mutually orthogonal center axes of the pattern sheet, Virtual grid defined; And a plurality of protruding ends protruding in opposite directions at opposite ends of each of the ribs of the virtual grid, and a protruding end formed at both ends of the protruding end of the protruding pattern sheet, And a mask frame for joining the protruding ends of the stretched ribs to each other.

An area of each of the plurality of protruding ends includes: a joint area bonded to the mask frame; And a bridge region connecting the junction region and the virtual lattice and not joined to the mask frame, wherein the edge of the pattern sheet is separated from the inner surface of the mask frame by a predetermined distance by the bridge region , Only the junction area of the projecting ends can be bonded onto the mask frame.

The mask frame has a rib groove, and the protruding end of the pattern sheet may be inserted into the rib groove and then joined.

The area of the ribs excluding the projecting ends may be formed of a thermal buffer structure including at least one of a through structure in which the pattern sheet thickness is completely removed and a groove structure in which the pattern sheet thickness is partially removed.

The area of the rib excluding the projecting ends is defined by an area other than the plurality of unit patterns for thin film processing among the pattern sheet areas; Or partially including the plurality of unit pattern regions for thin film processing among the pattern sheet regions.

According to the present invention, there is provided a mask assembly for patterning used in a thin film process, wherein a plurality of ribs crossing the main plane of the pattern sheet in two mutually orthogonal directions are defined, And the two ends of each of the ribs are pulled and bonded to the mask frame, thereby forming a large pattern sheet.

According to the present invention, the pattern sheet provides a characteristic defined as a virtual lattice of a kind of virtual ribs orthogonal to each other in two directions. Furthermore, according to the present invention, only the ribs forming the lattice of the pattern sheet are stretched. Further, according to the present invention, a feature is provided that it is bonded to the mask frame only in the rib end region of the pattern sheet.

It is conceivable that a virtual grid defined on the pattern sheet according to the present invention is formed, for example, by one or more virtual ribs in the X direction on the XY plane and one or more virtual ribs in the Y direction orthogonal thereto. The ribs in the same direction are arranged in parallel with each other. The virtual rib forming the virtual lattice can be defined independently of the position of each unit pattern portion (that is, for forming the thin film pattern) formed on the pattern sheet. In other words, the ribs forming the most lattice can be defined in the region between the unit pattern portions of the pattern sheet, and can also be defined as traversing the unit pattern subregion of the pattern sheet.

Therefore, according to the present invention, the region corresponding to the 'ribs' may include a solid region where the metal material forming the pattern sheet is physically continuous, as well as a space region where the metal material constituting the pattern sheet is physically absent.

According to the present invention, it is sufficient that tensile force is exerted on far fewer ribs than the existing case where tensile force is applied to all points of the edge of the pattern sheet in order to maintain the tension. Accordingly, the pattern sheet can maintain a sufficient tension by applying a tensile force of about 70% to that of the conventional pattern sheet.

Generally, the elasticity of a metal becomes weaker as it is stretched. Therefore, the pattern sheet according to the present invention, which applies a relatively small tensile force, can maintain a much larger elastic force than the conventional case of applying a relatively large tensile force, thereby making it possible to construct a stronger mask assembly against thermal shock.

Further, according to the present invention, not only the regions continuously bonded along the edges of the pattern sheet, but only the regions (or projecting ends) protruding from the ends of the ribs of the virtual lattice of the edge regions are bonded onto the mask frame. The edge portions of the pattern sheet on which the rib projecting ends are not formed may be spaced apart from each other so as not to directly contact the mask frame. In this case, only the rib projecting end portion of the edge of the pattern sheet is brought into contact with the mask frame. Therefore, the thermal stress generated in the mask frame and the open mask sheet can be mutually transferred only through the rib protruding end, so that the thermal stress transfer phenomenon as a whole can be minimized.

Furthermore, according to the present invention, the solid region of the virtual lattice of the pattern sheet is further provided with a thermal buffer structure such as a through-hole and / or a partial etched recess in which the open mask sheet thickness is entirely etched. Such through-holes and recessed structures increase the surface area of the open-mask sheet itself and minimize the contact area between the open-mask sheet and the substrate, as well as to ensure that deformation generated in the open-mask sheet is absorbed by the through- do. Thereby making it possible to construct a more robust mask assembly against thermal shock.

Further, according to the present invention, only a relatively narrow rib end protruding to the edge of the pattern sheet is sufficient to be bonded onto the mask frame. Therefore, it is possible to easily adapt the length and width of the rib end of the mask frame, thereby providing a merit that the mask assembly can be economically and efficiently provided by a simple process.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic plan view for illustrating a conventional mask assembly;
2 is a graph showing the deformation state of the edges and the center of a pattern sheet stretched in a conventional mask assembly.
3 is a schematic view illustrating a pattern shape of a pattern sheet provided in a conventional mask assembly;
4 is a schematic view showing the structure of a living pattern sheet according to an embodiment of the present invention;
5 is a schematic view for explaining a rib pulling method of a large pattern sheet according to the embodiment shown in Fig.
FIG. 6 is a flow chart illustrating a method of manufacturing a patterned sheet of large size according to the embodiment shown in FIG. 4;
7 is a schematic view showing the structure of a fine pattern sheet according to another embodiment of the present invention;
8 is a schematic view showing the structure of a fine pattern sheet according to another embodiment of the present invention;
FIG. 9 is a flow chart illustrating a method of manufacturing a fillet pattern sheet according to the embodiments shown in FIGS. 7 and 8. FIG.
10 is a schematic view showing a process of pulling a large pattern sheet according to an embodiment of the present invention and attaching it to a mask frame.
FIG. 11 is a schematic view showing a process of attaching a rib end to a mask frame by pulling a large pattern sheet according to an embodiment of the present invention in detail; FIG.
FIG. 12 is a schematic view showing a mask assembly in which a large pattern sheet according to an embodiment of the present invention is attached to a mask frame. FIG.
13 is a flow chart showing a process of pulling a large pattern sheet according to an embodiment of the present invention and attaching it to a mask frame to manufacture a mask assembly.
14 is a block diagram showing a configuration of an apparatus for manufacturing a mask assembly by pulling a large pattern sheet according to an embodiment of the present invention and attaching the same to a mask frame.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. The following description and drawings are only for illustrative purposes and are not intended to limit the scope of the invention. In other words, it is to be understood that the embodiments described below can be modified in various ways when they are implemented in the field, and if they are within the technical idea of the present invention, they should belong to the present invention. To be readily understood by those skilled in the art of marine technology.

1 is a schematic plan view for explaining a conventional mask assembly;

Referring to FIG. 1, a mask assembly 10 in the form of a pattern sheet 16 having a mask pattern 18 bonded to a mask frame 12 is shown. Such a mask assembly 10 is used in a thin film process for depositing and patterning a thin film of an electrode layer, a light emitting layer, an insulating layer and the like on a wafer substrate for manufacturing an OLED display provided in, for example, a smart phone or a smart watch. In the thin film process, particles such as metal, organic matter, or insulator can be deposited on the substrate in contact with the mask assembly 10 after passing through the mask pattern 18 of the mask assembly 10.

For precise thin film pattern formation, the mask assembly 10 must be uniformly adhered to the substrate. The mask frame 12 supports only the edge of the pattern sheet 16. Therefore, in order to prevent the center portion of the pattern sheet 16 from being struck by the load, the pattern sheet 16 is stretched by stretching the edges 16a, 16b, 16c, and 16d in the directions of the arrows shown, On the mask frame 12, for example, by laser spot welding. Further, the pattern sheet 16 is pulled by using a magnetic force across the wafer substrate and brought into close contact with the wafer substrate.

Thereby, a rectangular frame-shaped area 19 (a line indicated by dotted lines in the drawing) between the inner edge line 14 (line in the figure) of the mask frame 12 and the edges 16a, 16b, 16c and 16d of the pattern sheet 16 , The pattern sheet 16 is contacted and supported on the mask frame 12. [

However, since the mask assembly 10 for forming such a conventional thin film pattern has poor adhesion to the substrate due to thermal deformation due to long exposure to high temperature as the thin film process proceeds, the yield is greatly reduced due to the shadow phenomenon The problem is not solved.

FIG. 2 is a graph showing deformation of edges and a central portion of a pattern sheet stretched in a conventional mask assembly. FIG.

Referring to FIG. 2, a thermal deformation pattern 20 that may occur in a mask assembly, for example, as shown in FIG. 1, is illustrated. In this example, the mask assembly 10 comprises a pattern sheet 16 made of Invar alloy 0.1 to 0.2 mm thick and a mask frame 12 made of Invar alloy 900 mm x 800 mm x 23 mm, And is welded by laser spot welding.

As illustrated, the central portion 24 of the deformation pattern 20 shows a generally downwardly shaped configuration. This occurs because the central portion of the pattern sheet is not supported by the mask frame. However, it can be seen that there is a specific pattern which is deformed unevenly as a whole. Such a specific pattern is a deformation caused by a tensile force applied to impart a tensile force to the pattern sheet.

As can be seen, if the mask assembly is continuously exposed to high temperatures by continuation of a long thin film process, even if it is fine, in the state where the deformation has already begun by applying a tensile force to maintain tension, It is clear that the deformation state will be further enlarged.

Therefore, in order to solve the thermal deformation problem occurring in the mask assembly for forming a thin film pattern, if the tensile force applied to the pattern sheet is reduced and the thermal stress transferred between the mask frame and the pattern sheet is minimized, It is expected that the thermal deformation, particularly the deformation of the pattern sheet, can be greatly reduced.

3 is a schematic view illustrating a pattern shape of a pattern sheet provided in a conventional mask assembly.

Referring to Fig. 3, (a) of Fig. 3 shows a pattern sheet 32 in which rectangular patterns 33 are regularly arranged in a lattice pattern, for example, for a smart phone. Fig. 3 (b) shows the pattern sheet 34 in which the sector patterns 35 are regularly arranged in a lattice pattern, for example, for a vehicle instrument panel. On the other hand, FIG. 3 (c) shows a pattern sheet 32 in which circular unit patterns 37 are regularly arranged in a lattice pattern, for example, for a smart watch. In addition, the shape of the unit pattern itself may have a non-symmetrical shape, such as an instrument panel or a display panel in a vehicle.

In general, one substrate for OLED has a deposition surface of a size corresponding to about 30 to 250 OLED displays. To this end, one pattern sheet 32, 34, 36 also has a unit pattern corresponding to about 30 to 250 OLED displays 33, 35, 37). Although the plurality of unit patterns 33, 35 and 37 need not always be arranged in a lattice pattern on the pattern sheets 32, 34 and 36, due to the convenience of manufacturing and processing, the matrixes n, and m is an integer of 1 or more).

The main part that pulls and holds the center of the pattern sheets 32, 34, 36 against the gravitational force when the edges of the pattern sheets 32, 34, 33, 35, 37), it can be considered to be a region between the unit patterns 33, 35, 37 substantially.

Therefore, the present invention is based on the fact that an area between each unit pattern 33, 35, 37 in such pattern sheets 32, 34, 36 (for example, indicated by horizontal and vertical arrows in FIG. 3) vertial grid. Assuming that the entire pattern sheet 32, 34, 36 can be stretched sufficiently tightly by tensioning the horizontal and vertical ribs forming the virtual lattice.

The concept of the virtual lattice and ribs of the present invention can propose a new structure capable of minimizing the contact area between the mask frame and the pattern sheet by allowing only the both ends of the lattice of the lattice to contact the mask frame Let's do it. According to this new structure, not only the entire edges of the pattern sheet come into contact with the mask frame, but only the end of the virtual rib extended so as to protrude from the edge of the pattern sheet can be brought into contact with the mask frame. Thus, the contact area between the mask frame and the pattern sheet can be minimized, and consequently, the phenomenon that the thermal deformation of the mask frame is transferred to the pattern sheet can be minimized.

Hereinafter, with reference to Figs. 4 to 15, a large-sized pattern sheet constructed in accordance with the above-described virtual grid and ribbed concept, a mask assembly using the same, and a manufacturing method and apparatus thereof will be described.

4 is a schematic view showing the structure of a living pattern sheet according to an embodiment of the present invention.

Referring to Fig. 4, a fringe pattern sheet 40 is shown. Hereinafter, for convenience of explanation, the direction parallel to the X axis shown in the drawing is also referred to as a horizontal direction (or left and right direction), and a direction parallel to the Y axis perpendicular to the same plane in the same plane is referred to as a vertical direction Quot; The X axis and the Y axis are the center axes of the pattern sheet 40.

The 'virtual grid' assumed in the pattern sheet 40 according to the present invention and the virtual 'ribs' forming the virtual grid are arranged symmetrically about the X axis and the Y axis. Here, the term 'symmetrical' means that the distance between the ribs, the thickness of the ribs (that is, the length in the direction perpendicular to the longitudinal direction), the size and shape of the protruding ends at both ends of the rib, It can be used to mean that it is symmetrical around the center. This is to make it possible to apply a generally uniform tensile force to the generally rectangular pattern sheet 40.

The pattern sheet 40 includes a virtual grid consisting of a virtual rib 42 in the horizontal direction and a virtual rib 44 in the vertical direction. The virtual lattice may have a unit pattern formed in the pattern sheet 40 as a whole, i.e., a shape corresponding to an area between the pattern units 46.

Hereinafter, although the ribs of the virtual grid are defined in the solid region, except for the unit pattern portions 46, in the region of the entire pattern sheet 40, the present invention does not necessarily define only this type of rib. It is also possible to further define the ribs of the form passing through the unit pattern portion when a sufficient number of ribs can not be defined as the solid region between the unit pattern portions, such as when each unit pattern portion is large in size and irregular Do.

Both ends 43, 45 of each of the ribs 42, 44 protrude along the edge of the pattern sheet 40. The end portions 43 and 45 of the respective ribs 42 and 44 are provided in pairs in the same shape having the same width and the same length in the direction opposite to the ribs. The rectangular pattern portion 46 is defined by the ribs 42 and 44 of the pattern sheet 40. [ Needless to say, the pattern unit 46 may have various configurations. For example, in the case of an open mask assembly, the pattern portion 46 may simply be an entirely open hole with nothing in it. As another example, in the case of an FM mask assembly for forming each RGB pixel of the display, the pattern portion 46 may include a finer detail pattern defining each pixel.

In the illustrated example, the pattern sheet 40 has five horizontal ribs 42 parallel to the horizontal direction and nine vertical ribs 44 parallel to the vertical direction. Both ends of each of the ribs 42 or 44 has a pair of protruding ends 43 or 45 extending in different directions, either horizontally or vertically. The width W of each protruding end 43 or 45 need not be the same as the length L, but the protruding end pairs at one end of each of the ribs have the same width and length. The entire area of each of the protruding ends 43 and 45 can be separated on the mask frame into a bonding area 43a to be bonded, for example, by laser spot welding, and a non-bonding bridge area 43b. The bridge region 43b is an area that connects the bonding region 43a and the edge of the pattern sheet 40. [

Although in the illustrated example the pattern sheet has been described as having a certain number of horizontal ribs and vertical ribs and including a generally rectangular pattern portion defined by ribs, this is for exemplary purposes only, It is sufficient if the mask sheet is a mask sheet having regions between deposition patterns and it is obvious to those skilled in the art that the present invention need not be limited to pattern sheets of the illustrated type. Also, although the pattern sheet according to the present invention is described as being composed of one sheet or one sheet, this is merely an example. For example, the pattern sheet according to the present invention may include two or more strips or sticks of two or more layers.

FIG. 5 is a schematic view for explaining a rib pulling method of a large pattern sheet according to the embodiment shown in FIG.

5, the pattern sheet 50 includes a plurality of ribs 52 parallel to each other in the horizontal direction, a plurality of ribs 54 parallel to each other in the vertical direction, and a plurality of ribs 54 surrounded by the ribs 52, And a pattern portion 56 of the pattern. Both ends of the ribs of the pattern sheet 50 protrude from the edge of the pattern sheet 50. Each of the horizontal ribs 52 has two protruding ends 53-1 and 53-2 which extend in opposite directions in the longitudinal direction thereof, that is, the horizontal direction. The two protruding ends (53-1, 53-2) are paired with each other in the extension direction and the same size and shape with respect to the ribs. Likewise, each of the vertical ribs 54 has two protruding ends 55-1 and 55-2 which extend in opposite directions in the longitudinal direction thereof, that is, the vertical direction. The two protruding ends 55-1 and 55-2 are paired with each other in the extension direction and the same size and shape with respect to the ribs.

FIG. 6 is a flow chart illustrating a method of manufacturing a large pattern sheet according to the embodiment shown in FIG.

Referring to FIG. 6, first, a metal sheet made of, for example, an invar alloy is prepared. In the case of the wet etching method according to the present invention, a large pattern sheet according to the present invention can be manufactured by forming a predetermined mask pattern on the metal sheet and a pattern for protruding ends of the ribs, and then etching the metal sheet using a predetermined etching solution. In addition, a large pattern sheet can be manufactured by a dry etching method, a laser processing method, or the like.

In the illustrated example, first, a protective layer of a material that does not react with the etching liquid is formed on the metal sheet (61). A final mask pattern and an etch pattern for the rib pattern are formed on the protective layer using, for example, a laser (63). The etching pattern is formed by removing a part of the protective layer. Then, etching treatment is performed by treating with an etching solution (65). Then, except for the portion of the metal sheet where the protective layer is covered, the portion of the metal sheet from which the protective layer has been removed is melted and removed by the etching solution. Thereafter, if the protective layer is removed (67), finally, a large pattern sheet 40 is formed, for example, the pattern sheet shown in Fig. 4, that is, the pattern portion 46 and the protruding ends 43 and 45 are formed 69).

The above-described fabrication process of the large-sized pattern sheet is similar to that of the mask sheet in which the mask pattern is formed by the conventional etching, except that only the protruding end is formed. Therefore, the method of manufacturing a large pattern sheet according to the present invention provides an advantage that it can be manufactured through a conventional process of manufacturing a mask sheet.

FIG. 7 is a schematic view showing the structure of a fine pattern sheet according to another embodiment of the present invention. FIG.

Referring to Fig. 7, there is shown a large pattern sheet 70 in which a through hole and a concave structure are additionally formed in the rib area of the large pattern sheet 40 of Fig.

The pattern sheet 70 according to the present invention includes a virtual grid consisting of a virtual rib 72 in the horizontal direction and a virtual rib 74 in the vertical direction similar to the pattern sheet 40 in Fig. 72, and 74, respectively. Both ends of each of the ribs 72 or 74 are provided with pairs of protruding ends 73 or 75 extending in different directions, which are horizontal or vertical, respectively.

In the illustrated example, the pattern sheet 70 has the through holes 77 and / or the grooves 78 added to each of the ribs 72 and 74 in addition to the configuration of the pattern sheet 40 shown in Fig. . The through hole 77 is a hole which completely penetrates the thickness of the pattern sheet 70, and the groove 78 is a concave portion which is cut by about half. These through grooves 77 and recesses 78 allow the surface area of the pattern sheet 70 to be increased and the thermal diffusivity to be increased while minimizing the contact area between the pattern sheet 70 and the substrate during the thin film process, It can serve as a buffer for absorbing the heat deformation phenomenon generated in the sheet 70.

The through holes 77 may be formed in combination with an etching process for forming the pattern portions 76. In the case of the groove 78, this can be done by a half-etching process. The half etching process can be performed using the same etching solution and process as the etching process for forming the through hole 77 and the pattern portion 76.

8 is a schematic view showing the structure of a living pattern sheet according to another embodiment of the present invention.

Referring to Fig. 8, a large pattern sheet 80 is shown in which a guard strip is formed outside the projecting end of the fringe pattern sheet 70 of Fig.

The pattern sheet 80 according to the present invention has a virtual lattice consisting of a virtual rib 82 in the horizontal direction and a virtual rib 84 in the vertical direction similar to the pattern sheets 40 and 70 of FIG. And includes a pattern portion 86 surrounded by ribs 82, Both ends of each of the ribs 82 and 84 are provided with pairs of protruding ends extending in different directions, which are horizontally or vertically, respectively.

The guard strip 88 formed outside the protruding ends 83 and 85 may serve to protect the protruding ends 83 and 85 but it is preferable that when the protruding ends 83 and 85 are connected to the tension device It can serve as an auxiliary tool for easy connection.

The guard strip 88 is removed since it is not necessary after the pattern sheet 80 is bonded to the mask frame. To facilitate this, a guard strip 88 is formed between the guard strip 88 and the protruding ends 83, May be formed. In one example, the cutting line 89 is in the form of a half of the thickness of the metal sheet, in which case the guard strip 88 can be readily removed by a simple operation of holding the guard strip 88 by hand do.

The guard strip 88 is formed by the edge portion of the metal sheet for fabricating the pattern sheet 80 and is formed by removing the area between the guard strip 88 and the protruding ends 83,85 So that it can be manufactured together with an etching process for forming the pattern portion 86. In the case of the cutting line 89, this can be done by a half-etching process. The half etching process may be performed using the same etching solution and process as the etching process for forming the guard strip 88 and the pattern portion 86 as described above.

FIG. 9 is a flow chart illustrating a method of manufacturing a large pattern sheet according to the embodiments shown in FIGS. 7 and 8. FIG.

Referring to FIG. 9, first, a metal sheet made of, for example, an invar alloy is prepared. 7 and 8, the metal sheet is provided with a predetermined mask pattern, a guard strip and a full etching pattern for protruding ends of the ribs, and a half etching pattern for forming recesses, Followed by etching treatment.

To this end, a protective layer made of a material which does not react with the etching liquid is formed on the metal sheet (91). The protective layer forms (93) a mask pattern and an etch pattern for the rib pattern, through-hole, and / or guard strip and a half-etch pattern for the cut line and / or groove. Then, etching and half-etching are performed (95) by treating the etching pattern and the half-etching pattern formed thereon with an etching solution for a predetermined time. Then, the portion of the metal sheet corresponding to the etching pattern and the half-etching pattern in the metal sheet is melted or removed by the etching solution, or half of the thickness is shaved. Thereafter, the protective layer is removed (97), and finally the pattern sheets (70, 80) shown in FIG. 7 or 8, for example, are produced (99).

The above-described fabrication process of the large-sized pattern sheet is similar to that of the mask sheet using the conventional etching pattern and half-etching pattern, except that the protruding end, the guard strip connected thereto, Such as through holes and / or grooves, and / or cutting lines, are further formed. Therefore, the method of manufacturing a large pattern sheet according to the present invention provides an advantage that it can be manufactured through a conventional process of manufacturing a mask sheet.

10 is a schematic view showing a process of pulling a large pattern sheet according to an embodiment of the present invention and attaching it to a mask frame.

Referring to FIG. 10, the protruding ends 105 of the virtual ribs of the large-sized pattern sheet 104 having the structure as described above are stretched in pairs and are bonded to the mask frame 102 intuitively.

In the figure, each arrow indicates the direction and position at which the ribs between the pair of protruding ends 105 are simultaneously stretched. Practically, such tensile direction and tensile position can be obtained by, for example, a process of stretching the edges of a single pattern sheet in which an opening pattern for a predetermined thin film pattern is formed as described above with reference to Fig. 1 and joining the edges to the mask frame And is very similar overall.

However, in contrast to conventionally holding the edges of the pattern sheet as a whole or in sparsely spaced positions and applying a tensile force to the entire area of the pattern sheet, the present invention is characterized in that, in the area of the pattern sheet 104, And each of the ribs of this virtual grid is stretched. That is, according to the present invention, tensile force is applied to the ribs between the pairs of protruding ends (105) protruding in opposite directions at positions spaced apart from each other at the edges of the pattern sheet.

Further, in contrast to conventionally joining the mask frame continuously along the edge of the pattern sheet, the present invention is characterized in that a virtual grid is arbitrarily defined in the region of the pattern sheet 104, and both ends of each rib of this virtual grid, There is a difference in that at least a part of the protruding end 105 protruding from a position spaced apart from the edge of the pattern sheet is bonded to the mask frame 102.

Accordingly, the present invention is very similar to the process of pulling the edges of a conventional single mask sheet and joining edges thereof to the mask frame. Therefore, It provides the advantage of being available through.

Further, since the present invention joins only the protruding end pairs of the pattern sheet to the mask frame, compared with the conventional method of joining the entire edge of the mask sheet to the mask frame, the contact area between the mask frame and the pattern sheet is minimized It is possible to provide the advantage.

Further, according to the present invention, since only the protruding end pairs of the pattern sheet are uniformly stretched and bonded to the mask frame in comparison with the conventional method of uniformly stretching the entire edge of the mask sheet to join the mask frame, The advantage of being able to provide sufficient tension even with less tension can be provided.

In the illustrated example, the mask frame 102 has a protruding region 103 formed along the inner edge so that the protruding ends 105 of the pattern sheet 104 are easily joined. The protruding end 105 of the pattern sheet 104 can be welded while being inserted into the rib groove formed on the protruding area 103. [

FIG. 11 is a schematic view showing a step of attaching a rib end portion in a process of pulling a large-sized pattern sheet according to an embodiment of the present invention shown in FIG. 10 and attaching it to a mask frame in detail.

Referring to Fig. 11, the rib end or protruding end 116 of the pattern sheet may be laser spot welded, for example, while being inserted into the rib groove 114. The rib groove 114 is formed by partially cutting out the portion to which the protruding end 116 is to be joined in the protruding region 112 (corresponding to the protruding region 103 in Fig. 10) formed along the inner edge of the mask frame 110 . In this case, an advantage is provided that the top surface (i.e., the top surface of the protruding end 116) of the pattern sheet can be placed on the same surface as the top surface of the mask frame 110. [

FIG. 12 is a schematic view showing a mask assembly in which a large pattern sheet according to an embodiment of the present invention is attached to a mask frame. FIG.

Referring to FIG. 12, a mask assembly 120 in which a large-sized pattern sheet 124 is bonded to a mask frame 122 is illustrated. In the illustrated example, the pattern sheet 124 has a plurality of horizontal ribs 1242 and a plurality of vertical ribs 1244, and a plurality of pattern portions 1246 defined thereby.

Only the bonding region 1245a which is a part of the protruding ends 1245 of the vertical rib 1244 of the pattern sheet 124 is bonded to the rib groove of the mask frame 122 as shown. On the other hand, the bridge region 1245b, which is the remaining part of the protruding ends 1245, is not bonded to the mask frame 122. As a result, the inner edge line 1221 of the mask frame 122 and the edges of the pattern sheet 124 can be spaced away from each other with a spacing 128 therebetween. This structure is also applied to the protruding end 1243 of the horizontal rib 1242 similarly.

As a result, the pattern sheet 124 can maintain sufficient tension by a much smaller tensile force, and at the same time, the contact area between the mask frame 122 and the pattern sheet 124 can be made very small. As a result, since the mask frame 122 and the pattern sheet 124 are made of different materials or different materials from each other, when the thermal deformation occurs at the same temperature, the mask frame 122 and the pattern sheet 124 The thermal stress can be minimized.

13 is a flowchart showing a process of manufacturing a mask assembly using a large pattern sheet.

Referring to FIG. 13, a method of manufacturing a mask assembly 140 according to an embodiment of the present invention is illustrated. First, a step 131 of fabricating a mask frame having a rib groove and a step 133 of fabricating a large pattern sheet according to the present invention are performed. The two steps can be carried out in different orders or simultaneously.

In this case, the mask frame includes a rectangular frame portion surrounding a generally rectangular opening. Such a mask frame may be made of, for example, an invar alloy or stainless steel (SUS420) having a thickness of about 5 to 80 mm. A plurality of rib grooves may be formed on the protruding region formed on the inner surface side of the rectangular frame of the mask frame. Although the mask frame in this example has a rib groove, it is obvious that the present invention does not necessarily use a mask frame having a rib groove, and that a mask frame without a rib groove can be used.

On the other hand, the pattern sheet may be formed of one sheet, but may be formed of two or more members or two or more members as another example. The pattern sheet is formed with a unit pattern for deposition and protruding ends and / or other accessory structures at both ends of the strip. These patterns, protrusions and / or accessory structures may be formed by, for example, wet etching, dry etching, or laser processing. The pattern sheet may be formed of, for example, an invar alloy, and the thickness may be about 0.01 to 5 mm.

After the mask frame and the large pattern sheet are prepared as described above, the large pattern sheet is then stretched and bonded to the mask frame. First, at the stretching step 135, the pairs of protruding ribs protruding along the edges of the large-sized pattern sheet are pulled in opposite directions to stretch the ribbons.

Finally, of the pattern sheets that have been subjected to tensioning in the vertical and horizontal directions in the joining step 137, the protruding ends along the edge thereof are inserted into the rib grooves of the mask frame, .

14 is a block diagram showing a configuration of an apparatus for manufacturing a mask assembly using a large pattern sheet according to an embodiment of the present invention.

Referring to FIG. 14, the structure of an apparatus for manufacturing a mask assembly 140 according to an embodiment of the present invention is illustrated. In the illustrated example, the apparatus for manufacturing a mask assembly 140 is an assembling apparatus for manufacturing a mask assembly using a pattern sheet and a mask frame that are manufactured in advance. This apparatus is an apparatus for marking an alignment mark while stretching the pattern sheet and joining the mask sheet on the mask frame. The manufacturing apparatus 140 may include a control unit 141, a tension unit 143, a bonding unit 145, and a marking unit 147.

The control unit 141 is a control component that controls each part. Although not shown, the control unit 141 includes not only a processing device for controlling each part but also an input / output device for allowing a user to operate the device and input necessary commands or design data, and programs and data And a sensor (e.g., a camera module, etc.) that senses at least a portion of the mask assembly to determine the position of the alignment mark.

The tension portion 143 is a component for tensioning the protruding end pairs formed along the edges of the pattern sheet manufactured according to the present invention. The tensioning portion 143 can be similarly configured using a tensioning device used when tensioning the edge of a conventional mask sheet. The tension portion 143 according to the present invention is configured to fix a pair of protruding ends formed along the edges of the pattern sheet, respectively, and to apply a tensile force in the opposite direction.

The joining portion 145 is a component that joins a plurality of protruding ends, which are stretched on a mask frame or a rib groove formed on the mask frame, in an inserted state. For example, a laser welder for laser spot welding a pattern sheet on a mask frame. The joints 145 may be similarly configured using a joining apparatus used when manufacturing conventional mask assemblies. In this case, the conventional laser welder performs spot welding along the edge of the pattern sheet, whereas the laser welder according to the present invention differs only in welding along the protruding end of the pattern sheet.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Of course, fall within the scope of the present invention.

Claims (20)

A pattern sheet comprising a plurality of unit patterns for thin film process, joined to a mask frame of a mask assembly for thin film process with a predetermined tensile force applied thereto,
A virtual lattice defined by a plurality of ribs each extending in two mutually orthogonal directions defined on the surface of the pattern sheet and symmetrically arranged with respect to two mutually orthogonal center axes of the pattern sheet;
A plurality of protruding ends protruding in opposite directions at opposite ends of each of the ribs of the virtual lattice; And
A plurality of protruding ends are connected to the inner ends of the plurality of protruding ends, and a guard strip in the form of surrounding the area of the pattern sheet
A large pattern sheet to buy included.
The method according to claim 1,
Wherein the plurality of protruding ends
They have the same width and length at each end of each strip;
Wherein the pattern sheet is arranged symmetrically with respect to two mutually orthogonal center axes of the pattern sheet.
3. The method of claim 2,
Wherein the area of each of the plurality of protruding ends,
A joint region bonded to the mask frame; And
And a bridge region connecting said junction region and said virtual lattice and not bonded to said mask frame.
The method of claim 3,
The junction region has a constant width (W)
Wherein the width of the bridge region increases gradually or stepwise from the width size of the junction region to the virtual lattice.
The method according to claim 1,
The area of the rib, excluding the protruding end,
Wherein the pattern sheet area is defined by an area other than the plurality of unit patterns for thin film processing among the pattern sheet areas.
The method according to claim 1,
The area of the rib, excluding the protruding end,
And a plurality of thin film process unit pattern regions partially defined in the pattern sheet region.
The method according to claim 1,
The area of the rib, excluding the protruding end,
Wherein a thermal buffer structure is formed that includes at least one of a through structure in which the pattern sheet thickness is completely removed and a recess structure in which the pattern sheet thickness is partially removed.
delete The method according to claim 1,
Wherein a cut line is formed at a portion connected to the guard strip and the plurality of protruding ends, the cut line being formed by removing the pattern sheet at least partially in order to facilitate cutting.
A manufacturing method of a mask assembly for a thin film process,
A pattern sheet joined to the mask frame of the mask assembly in a state in which a predetermined tensile force is applied and having a plurality of unit patterns for thin film process, each extending in two orthogonal directions defined by the surface of the pattern sheet, A virtual lattice defined by a plurality of ribs symmetrically arranged with respect to two mutually orthogonal center axes of the pattern sheet; A plurality of protruding ends protruding in opposite directions at opposite ends of each of the ribs of the virtual lattice; And a guard pattern formed on the outside of the plurality of protruding ends and connected to the ends of the plurality of protruding ends so as to surround an area of the pattern sheet;
A pulling step of pulling each of the ribs of the virtual grid through the guard strip in opposite directions opposite to each other;
A joining step of joining at least some of the regions of each of the projecting ends to the mask frame in the pulled-up state and then cutting the guard strip
A method for manufacturing a mask assembly using a large pattern sheet.
11. The method of claim 10,
In the joining step,
In which a projecting end of the pattern sheet protruding therefrom is arranged so as to be spaced apart from the inner surface of the mask frame by a predetermined distance, A method of manufacturing a mask assembly using a sheet.
11. The method of claim 10,
Wherein the mask frame has a rib groove through which the projection ends of the pattern sheet are inserted and joined,
Wherein the protruding end of the pattern sheet is inserted into the rib groove and then bonded to each other in the joining step.
delete An apparatus for manufacturing a mask assembly for a thin film process,
A pattern sheet comprising a plurality of unit patterns for thin film process which are joined in a state in which a predetermined tensile force is applied to a mask frame and each extending in two mutually orthogonal directions defined by the surface of the pattern sheet, A virtual lattice defined by including a plurality of ribs symmetrically arranged with respect to two orthogonal center axes; A plurality of protruding ends protruding in opposite directions at opposite ends of each of the ribs of the virtual lattice; And a guard strip which is connected to the ends of the plurality of protruding ends inside the plurality of protruding ends and which surrounds the area of the pattern sheet and which surrounds the pattern sheet, A stretching unit that stretches each of the ribs of the virtual lattice in opposite directions opposite to each other;
And a joining portion for joining at least a part of the regions of each of the projecting ends to the mask frame in the pulled state and then cutting the guard strip
Wherein the mask pattern is formed on the mask pattern.
15. The method of claim 14,
The joining portion
In which a projecting end of the pattern sheet protruding therefrom is arranged so as to be spaced apart from the inner surface of the mask frame by a predetermined distance, A device for manufacturing a mask assembly using a sheet.
A mask assembly for a thin film process, wherein a pattern sheet having a plurality of unit patterns for thin film processing is bonded on a mask frame,
Wherein the pattern sheet is bonded to the mask frame in a state in which a predetermined tensile force is applied thereto and extends in two mutually orthogonal directions defined by the surface of the pattern sheet, A virtual lattice defined by a plurality of ribs arranged symmetrically with respect to each other; A plurality of protruding ends protruding in opposite directions at opposite ends of each of the ribs of the virtual lattice; And a guard strip formed on the outside of the plurality of protruding ends and connected to the ends of the plurality of protruding ends at an inner side thereof and surrounding the area of the pattern sheet,
Wherein each of the ribs of the virtual grid is biased in mutually opposite directions through the guard strip of the palladium pattern sheet and the guard strip is cut after the protruding ends of the stretched rib are bonded onto the mask frame Wherein the patterned large-sized pattern sheet is bonded onto the mask frame
Wherein the mask pattern comprises a patterned sheet.
17. The method of claim 16,
An area of each of the plurality of protruding ends includes: a joint area bonded to the mask frame; And a bridge region connecting the junction region and the virtual lattice and not bonded to the mask frame,
Wherein the mask frame is bonded on the mask frame so that the edge of the pattern sheet is spaced apart from the inner surface of the mask frame by the bridge region at a predetermined distance, Mask assembly.
17. The method of claim 16,
Wherein the mask frame has a rib groove and the protruding end of the pattern sheet is inserted into the rib groove and then bonded.
17. The method of claim 16,
The area of the rib, excluding the protruding end,
Wherein a thermal buffer structure is formed that includes at least one of a through structure in which the pattern sheet thickness is completely removed and a recess structure in which the pattern sheet thickness is partially removed.
17. The method of claim 16,
The area of the rib, excluding the protruding end,
Or defined by regions other than the plurality of unit patterns for thin film processing among the pattern sheet regions; or
And a plurality of unit pattern regions for thin film processing,
A mask assembly comprising a large pattern sheet.

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