KR20230151268A - Method for fabricating oled mask frame - Google Patents

Abstract

According to one embodiment of the present invention, in manufacturing an OLED mask frame, four metal bars forming a square mask frame and an auxiliary block are manufactured to support the metal bars connected at each corner so that the four metal bars form a square frame shape. , An inclined cutting surface is formed in a certain area from the contact surface where different metal bars are in contact with each other. Using an auxiliary block, a preliminary frame is formed so that the cutting surfaces of four metal bars are connected to each other to form a square frame, and then vacuum. By electron beam welding the contact line and cutting surface of the contact area in the chamber to bond the four metal bars to each other in a square shape, a highly durable mask frame can be formed and the material wasted in manufacturing the mask frame can be minimized.

Description

OLED mask frame manufacturing method {METHOD FOR FABRICATING OLED MASK FRAME}

The present invention relates to the production of a large-area frame used in the production of an OLED metal mask. More specifically, the four metal bars that form a square mask frame and the four metal bars support the metal bars connected at each corner to form a square frame. An auxiliary block is manufactured, and an inclined cutting surface is formed at a certain area from the contact surface where different metal bars are in contact. Using the auxiliary block, four metal bars are prepared so that the cutting surfaces are connected to each other to form a square frame. After forming the frame, the contact lines and cutting surfaces on the contact parts are electron beam welded in a vacuum chamber to bond four metal bars to each other in a square shape to form a highly durable mask frame and minimize wasted materials in manufacturing the mask frame. This relates to a method of manufacturing an OLED mask frame.

In general, organic light-emitting displays (OLEDs, Organic Light-Emitting Diodes) are widely used as display devices installed in televisions, monitors, tablet PCs, smartphones, smartwatches, and vehicle dashboards.

In addition, when manufacturing OLED, a thin film process is required to stack and pattern multiple thin film layers such as electrode layers, organic light emitting layers, and insulating films, and the thin film process uses a mask assembly each equipped with a corresponding pattern, such as chemical vapor deposition (chemical vapor deposition). Includes CVD (chemical vapor deposition), sputtering, ion plating, vacuum deposition, etc.

The mask assembly used in this thin film process typically has a structure in which a relatively thin metal mask sheet is bonded to a relatively strong metal mask frame. The mask frame is a frame structure in the form of a window or door frame with a thickness of approximately 5 to 80 mm and functions as a support to maintain the overall shape of the mask assembly stably. The mask sheet is a thin metal sheet with a thickness of approximately 0.01 to 5.00 mm and includes a mask pattern to be used during deposition. The mask sheet and mask frame that make up the mask assembly for this thin film process are, for example, stainless steel or titanium (Ti) metal such as SUS420, or special metal with a very small coefficient of thermal expansion according to temperature changes, such as Invar-36 Alloy. It is manufactured using .

In addition, because of the high precision required for the mask assembly, structural stability of the parts constituting the mask assembly is an essential requirement, and for this purpose, a method of manufacturing not only the metal sheet but also the base frame in an integrated form is generally adopted. In other words, first prepare a flat metal plate having the desired thickness and overall size of the base frame, then cut the inside of the prepared metal plate to produce a preliminary frame having a square closed loop shape.

The final mask frame is then manufactured by smoothing the surface of the preliminary frame and processing patterns for necessary structures such as mounting grooves.

However, since the materials for manufacturing the mask frame are very expensive, the mask frame conventionally manufactured in an integrated form as above corresponds to an area that is relatively much larger than the area of the square frame shape left out of the total area of the metal plate during the manufacturing process. Since the inner area is cut and discarded, there is a problem that the overall cost of manufacturing the mask frame is very high.

Republic of Korea Patent Publication No. 10-2015-0071321 (publication date: June 26, 2015)

Therefore, the purpose of the present invention is to manufacture an OLED mask frame, to manufacture four metal bars forming a square mask frame and an auxiliary block to support the metal bars connected at each corner so that the four metal bars form a square frame, and to manufacture the metal bar. An inclined cutting surface is formed at a certain area from the contact surface where different metal bars are in contact. Using an auxiliary block, a preliminary frame is formed so that the cutting surfaces of four metal bars are connected to each other to form a square frame, and then the cutting surfaces are formed in a vacuum chamber. Provides an OLED mask frame manufacturing method that forms a highly durable mask frame and minimizes the material wasted in manufacturing the mask frame by bonding four metal bars to each other in a square shape by electron beam welding the contact line and cutting surface of the contact area. It is done.

The objects of the present invention are not limited to the objects mentioned above, and other objects and advantages of the present invention that are not mentioned can be understood by the following description and will be more clearly understood by the examples of the present invention. Additionally, it will be readily apparent that the objects and advantages of the present invention can be realized by the means and combinations thereof indicated in the patent claims.

The OLED mask frame manufacturing method according to the present invention includes the steps of manufacturing a straight first metal bar and a second metal bar having a first width, a first length, and a first thickness, and the second width, the second length, and the second thickness. A step of manufacturing a primary-type third metal bar and a fourth metal bar having a step of manufacturing a four-corner alignment block in the shape of a bracket having an internal angle of 90 degrees and a third thickness thinner than the first thickness, and a corner Forming a preliminary frame by placing alignment blocks at the four corners of the square forming the mask frame and arranging each metal bar in a square shape, and tack welding a portion of the contact line of the contact surface where each metal bar forming the preliminary frame is in contact. It may include manufacturing a mask frame by performing electron beam welding on the entire contact line of each metal bar on the tack-welded preliminary frame in a vacuum chamber.

In addition, forming the preliminary frame includes adjusting the position of each corner alignment block to correspond to the shape of the mask frame on a base panel of a flat plate capable of adjusting the position of the corner alignment block, and aligning the adjusted edge. It may include the step of forming a preliminary frame of a square frame in which each corner is supported by a corner alignment block by placing each metal bar on each side of the square frame in the internal space of the block.

In addition, each metal bar has a cutting surface with a specific inclination angle formed on the upper and lower parts of the contact area in a certain area defined from the contact surface in contact with another metal bar in contact with the preliminary frame, and two cutting surfaces are formed during electronic non-welding. It can be welded so that the cutting groove forming it is filled.

In addition, the third thickness of each corner alignment block is determined as a thickness located lower than the first position where the cutting surfaces meet on the side contact line formed on the side of each metal bar among the contact lines, and in the tack welding step, the side contact line Two contact metal bars can be tack-welded by arc welding between a first position on the contact line and a second position where the corner auxiliary block is located.

In addition, the manufacturing method may further include a post-processing step of performing surface processing and thickness processing on the mask frame after manufacturing the mask frame.

According to one embodiment of the present invention, in manufacturing an OLED mask frame, four metal bars forming a square mask frame and an auxiliary block are manufactured to support the metal bars connected at each corner so that the four metal bars form a square frame shape. , An inclined cutting surface is formed in a certain area from the contact surface where different metal bars are in contact with each other. Using an auxiliary block, a preliminary frame is formed so that the cutting surfaces of four metal bars are connected to each other to form a square frame, and then vacuum. By electron beam welding the contact line and cutting surface of the contact area in the chamber to bond the four metal bars to each other in a square shape, a highly durable mask frame can be formed and the material wasted in manufacturing the mask frame can be minimized.

In addition to the above-described effects, specific effects of the present invention are described below while explaining specific details for carrying out the invention.

1 is a flowchart of a mask frame manufacturing process for a mask assembly for thin film processing according to an embodiment of the present invention.
Figure 2 is a schematic diagram illustrating a tack welding step during the manufacturing process of a mask frame for a mask assembly for thin film processing according to an embodiment of the present invention.
Figure 3 is a partial enlarged view showing the configuration of a joint line of a preliminary frame tack-welded during the manufacturing process of a mask frame for a mask assembly for thin film processing according to an embodiment of the present invention.
Figure 4 is a cross-sectional view of a metal bar bonded during the manufacturing process of a mask frame for a mask assembly for thin film processing according to an embodiment of the present invention.
Figure 5 is a schematic diagram illustrating the formation of a preliminary frame using corner alignment blocks during the manufacturing process of a mask frame for a mask assembly for thin film processing according to an embodiment of the present invention.

Hereinafter, the operating principle of the present invention will be described in detail with reference to the attached drawings. In the following description of the present invention, if a detailed description of a known function or configuration is judged to unnecessarily obscure the gist of the present invention, the detailed description will be omitted. The terms described below are defined in consideration of the functions in the present invention, and may vary depending on the intention or custom of the user or operator. Therefore, the definition should be made based on the contents throughout this specification.

1 is a flowchart of a mask frame manufacturing process for a mask assembly for thin film processing according to an embodiment of the present invention.

Figure 2 is a schematic diagram illustrating a tack welding step during the manufacturing process of a mask frame for a mask assembly for thin film processing according to an embodiment of the present invention.

Figure 3 is a partial enlarged view showing the configuration of a joint line of a preliminary frame tack-welded during the manufacturing process of a mask frame for a mask assembly for thin film processing according to an embodiment of the present invention.

Figure 4 is a cross-sectional view of a metal bar bonded during the manufacturing process of a mask frame for a mask assembly for thin film processing according to an embodiment of the present invention.

Figure 5 is a schematic diagram illustrating the formation of a preliminary frame using corner alignment blocks during the manufacturing process of a mask frame for a mask assembly for thin film processing according to an embodiment of the present invention.

Hereinafter, the mask frame manufacturing process for the mask assembly for thin film processing according to an embodiment of the present invention will be described in more detail with reference to FIGS. 1 to 5.

First, four straight metal bars (210, 212, 230, 232) to create a mask frame are manufactured (S110).

Among these metal bars, the first metal bar 210 and the second metal bar 212 form the long side of the mask frame 330, and the third metal bar 230 and the fourth metal bar form the short side of the mask frame 330. It may include a metal bar 232. At this time, each metal bar 210, 212, 230, 232 is preferably made of a low thermal expansion metal such as stainless steel, titanium-based, or nickel-based alloy. For example, the metal plate conventionally used to manufacture an integrated mask frame is cut straight. It can be easily manufactured by doing this.

Also, for example, the first metal bar and the second metal bar have a first width, a first length, and a first thickness, and the third metal bar and the fourth metal bar have a second width, a second length, and a second thickness. The first width and the second width can be manufactured to be the same, and the first thickness and the second thickness can also be manufactured to be the same, but are not limited to this. Additionally, the width, length, and thickness of each metal bar may have various dimensions depending on the size of the mask frame or its intended use.

In addition, for example, when manufacturing the square frame shape of a mask frame for a mask assembly by combining four metal bars, the dimensions of each metal bar range from, for example, 20 to 70 mm in thickness, 90 to 500 mm in width, and 500 to 4,000 mm in length. You can. The thickness of the mask frame manufactured by combining four such metal bars can be 20 to 70 mm, similar to the thickness of the metal bars, and the width and length of the mask frame can be 500 to 4,000 mm, respectively, corresponding to the length of the metal bars. there is. Here, those skilled in the art will know that the larger the size of the mask frame manufactured by combining these metal bars, the larger the size of the opening formed in the mask frame is, so the conventional mask frame is manufactured as an integrated piece. It will be obvious that the material saving effect can be greater when manufacturing a mask frame compared to the case of making a mask frame.

In addition, as shown in FIGS. 3 and 4, each metal bar has a cutting surface 462 with a specific inclination angle on the contact portion 450 of a certain area defined from the contact surface in contact with another metal bar in contact with the preliminary frame. They are each formed at the bottom, and are welded so that the cutting grooves formed by the two cutting surfaces are filled during electron beam welding, thereby improving the durability of the joint between metal bars.

After such electron beam welding, the welded portion 482 on the contact portion may be polished to form the same plane as the upper and lower surfaces of the metal bar.

In addition, as shown in FIG. 4, the contact portion 450 is half-etched at the bottom of the first metal bar 210 and the second metal bar 212, and the bottom of the contact portion 450 is half-etched for the third metal bar 230 and the second metal bar 212. 4 In the case of the metal bar 232, the upper part is half-etched to facilitate alignment of the preliminary frame between the metal bars, and the bonding force at the contact surface between the metal bars can be further increased after electron blank welding.

Next, a corner alignment block 254, which is used as an aid in the process of joining four straight metal bars, is manufactured (S112).

As shown in FIG. 2, this corner alignment block 254 can be manufactured in a bracket shape with an internal angle of 90 degrees and a third thickness thinner than the first thickness, and the metal bars 210, 212, 230, and 232 ) is preferably made of the same metal as that of the

In addition, the corner alignment block can be placed at the corner of each metal bar when forming a preliminary frame by aligning each metal bar into a square frame shape to facilitate alignment of the square frame shape using each metal bar.

Additionally, the corner alignment block may be manufactured with a third thickness that is thinner than the first and second thicknesses of the metal bar. Accordingly, when a preliminary frame is created using a corner alignment block of a metal bar and then a part of the side of the contact line 452 of the contact surface where each metal bar is in contact on the preliminary frame is tack-welded, all sides of the contact line are covered by the corner alignment block. This prevents damage, and since the corner alignment block 452 is not tack-welded with the metal bar during tack welding, it is possible to recycle and use the corner alignment block.

In addition, the corner alignment block 254, similar to a metal bar, is manufactured by cutting a metal plate that has been conventionally used to manufacture an integrated mask frame, for example, or by cutting off scraps generated in the process of manufacturing a metal bar by cutting a metal plate. It can be produced using

Next, the corner alignment blocks 254 are placed at the four corners of the square forming the mask frame 330, and each metal bar is arranged in a square shape to form a preliminary frame (S114), and each metal bar forming the preliminary frame is in contact. Tack weld part of the contact line of the contact surface (S116).

At this time, as shown in FIG. 3, in the step of tack welding each metal bar on the preliminary frame, a portion of the side surface located on the upper part of the corner alignment block on the contact line is tack welded.

In this tack welding step, for example, a joint line 452 is formed by contacting each other at both ends of four metal bars on a flat jig, and corner alignment blocks are placed at each corner of a rectangular preliminary frame to prevent the joint line from deviating. Tack welding can be performed in a state where it is supported to prevent damage.

This tack welding 372 can be performed by arc welding two metal bars on both sides of the joint line. The tack strength may be sufficient to maintain the shape of the preliminary frame when the preliminary frame is later transferred to a vacuum chamber and then manufactured into a mask frame by performing electron beam welding within the vacuum chamber, but is not limited to this.

In addition, in the step of forming a preliminary frame, as shown in FIG. 5, for example, each corner alignment block is aligned to correspond to the shape of the mask frame on a flat base panel 520 where the position of the corner alignment block 254 can be adjusted. After adjusting the position, each metal bar can be placed on each side of the square frame in the inner space 555 of the position-adjusted corner alignment block to form a preliminary frame of the square frame with each corner supported by the corner alignment block. .

Next, electron beam welding is performed on the entire contact line 452 of each metal bar on the tack-welded preliminary frame in a vacuum chamber (S118).

At this time, the electron beam welding step 103 is a step in which the tack-welded preliminary frame is transferred to a vacuum chamber and electron beam welding is performed so that the four metal bars 1 are joined to each other at four joining lines.

In general, Electron Beam Welding (EBW) is also called E-beam welding. Electron beams with high kinetic energy emitted from an electron beam generator collide with the welded workpiece to melt and join the workpiece. It is a technology that makes it possible. This type of electron beam welding has the advantage of having extremely high energy density and welding efficiency and very little deformation of the base material, but it has limitations such as high manufacturing cost and limited working environments such as vacuum chambers. However, since the manufacturing field of the mask frame for the mask assembly for the deposition process, which is the field of application of the present invention, uses expensive metal materials, considering the cost of metal materials reduced by introducing electron beam welding, electron beam welding is preferred. Using this method can actually reduce the overall manufacturing cost of the mask frame.

When electron beam welding is completed, post-processing such as surface processing and thickness processing is performed on the welded preliminary frame (S120). In surface processing, the welded portion 482 of the welded preliminary frame is shaved off to be flat to match other surface portions, and the entire surface is chipped and trimmed to the design size to create a square-shaped mask frame 330 with a smooth and constant thickness. can be produced.

In addition, thickness processing may refer to processing to produce a structure such as a mounting groove (not shown) on a surface-processed preliminary frame.

Although the mask frame finally completed through the above post-processing was manufactured by joining the edges by electron beam welding, there was no difference in quality compared to the case where it was made as a single piece in the past, and the metallurgy was very uniform throughout the entire structure. It can have physical properties.

As described above, according to one embodiment of the present invention, in manufacturing an OLED mask frame, four metal bars forming a square mask frame and supporting metal bars connected at each corner so that the four metal bars form a square frame shape An auxiliary block is manufactured, and an inclined cutting surface is formed in a certain area from the contact surface where different metal bars are in contact. Using the auxiliary block, a preliminary frame is made so that the cutting surfaces of the four metal bars are connected to each other to form a square frame. After forming, the contact line and cutting surface of the contact part are electron beam welded in a vacuum chamber to bond the four metal bars to each other in a square shape to form a highly durable mask frame and minimize the material wasted in manufacturing the mask frame. do.

As described above, the present invention has been described with reference to the illustrative drawings, but the present invention is not limited to the embodiments and drawings disclosed herein, and various modifications may be made by those skilled in the art within the scope of the technical idea of the present invention. It is obvious that transformation can occur. In addition, although the operational effects according to the configuration of the present invention were not explicitly described and explained while explaining the embodiments of the present invention above, it is natural that the predictable effects due to the configuration should also be recognized.

210: first metal bar 212: second metal bar
230: Third metal bar 232: Fourth metal bar
254: Corner alignment block 330: Mask frame
450: contact part 452: contact line
482: welding part

Claims (5)

As a method of manufacturing an OLED mask frame,
Manufacturing a straight first metal bar and a second metal bar having a first width, a first length, and a first thickness;
Manufacturing a third metal bar and a fourth metal bar of a primary type having a second width, a second length, and a second thickness;
Manufacturing four corner-shaped alignment blocks with an internal angle of 90 degrees and a third thickness that is thinner than the first thickness;
Forming a preliminary frame by placing corner alignment blocks at the four corners of the square forming the mask frame and arranging each metal bar in a square shape;
A step of tack welding a portion of the contact line of the contact surface where each metal bar forming the preliminary frame is in contact;
A step of manufacturing a mask frame by performing electron beam welding on the entire contact line of each metal bar on the tack-welded preliminary frame in a vacuum chamber.
OLED mask frame manufacturing method comprising. According to claim 1,
The step of forming the preliminary frame is,
Adjusting the position of each corner alignment block to correspond to the shape of the mask frame on a flat base panel capable of adjusting the position of the corner alignment block;
An OLED mask frame manufacturing method comprising forming a preliminary frame of a rectangular frame in which each corner is supported by the corner alignment blocks by positioning each metal bar on each side of the rectangular frame in the internal space of the position-adjusted corner alignment block. According to claim 2,
Each metal bar,
Cutting surfaces with a specific inclination angle are formed on the upper and lower parts of the contact area in a certain area defined from the contact surface in contact with another metal bar in contact with the preliminary frame, and welded so that the cutting groove formed by the two cutting surfaces is filled during electronic ratio welding. OLED mask frame manufacturing method. According to claim 3,
The third thickness of each corner alignment block is,
It is determined by the thickness located lower than the first position where the cutting surfaces meet on the side contact line formed on the side of each metal bar among the contact lines,
In the tack welding step,
A method of manufacturing an OLED mask frame, which is a step of tack welding two contact metal bars by arc welding between a first position on the side contact line and a second position where the corner auxiliary block is located. According to claim 1,
The manufacturing method is,
After the step of manufacturing the mask frame,
An OLED mask frame manufacturing method further comprising a post-processing step of performing surface processing and thickness processing on the mask frame.

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