WO2023191594A1

WO2023191594A1 - Metal plate, deposition mask using same, and manufacturing method therefor

Info

Publication number: WO2023191594A1
Application number: PCT/KR2023/004397
Authority: WO
Inventors: 이상윤; 김지환
Original assignee: 스템코 주식회사
Priority date: 2022-03-31
Filing date: 2023-03-31
Publication date: 2023-10-05
Also published as: TW202349758A

Abstract

The purpose of the present invention is to manage an inclusion of a metal plate used to manufacture a high resolution deposition mask, and, accordingly, the present invention provides: a metal plate selection method for selecting a metal plate appropriate for an inclusion management standard; the metal plate according to the method; a deposition mask manufacturing method for manufacturing a deposition mask by using the metal plate; and the deposition mask manufactured according to the method.

Description

Metal plate, deposition mask using the same, and method of manufacturing the same

The present invention relates to a metal plate selected so that it can be used to manufacture an OLED display, a method of manufacturing a deposition mask using the metal plate, and a deposition mask manufactured according to the method.

OLED (Organic Light Emitting Diodes) is a self-luminous organic material that emits light by itself using the electroluminescence phenomenon. It makes it possible to produce thin flat displays and can also be applied to bendable or bendable displays. Because of this, it is receiving great attention in the display market today. In particular, recently, in response to demands for miniaturization and high precision, displays with a pixel density of 500 ppi (pixels per inch) or more or displays with a pixel density of 800 ppi or more have been in the spotlight.

When forming pixels of a display using the OLED, a method of forming pixels in a desired pattern using a metal mask including through holes arranged in a desired pattern is known. Specifically, first, a metal mask is brought into close contact with a substrate for an OLED display, and then both the metal mask and the substrate brought into close contact are put into a vapor deposition apparatus, and organic materials, etc. are deposited. Metal masks can generally be manufactured by forming through holes in a metal plate by etching using photolithography techniques.

In general, metal plates for metal masks can be manufactured by electroplating or rolling methods, and when the double rolling method is used, metal plates for metal masks with superior mechanical properties compared to electroplating methods can be manufactured. However, there is a problem in that the surface of the metal plate is scratched or scratched during rolling, or the metal plate contains inclusions of various sizes, and the shape of the through hole is damaged when the metal plate is etched. As a result, it was difficult to apply metal plates manufactured by rolling for metal masks used in high-resolution products or small products with narrow spacing between through holes.

In order to solve the above problems, the present invention aims to manage inclusions in a metal plate used to manufacture a high-resolution deposition mask.

The technical problem to be solved by the present invention is to provide a deposition mask manufacturing method for selecting a metal plate suitable for the inclusion management standards and manufacturing a deposition mask using the selected metal plate, and a deposition mask manufactured according to the method. It is done.

The technical problems of the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the description below.

One aspect of the metal plate of the present invention for achieving the above technical problem is a metal plate used to manufacture a deposition mask by forming a plurality of through holes. The metal plate has a thickness t0 of 50 μm or less, and the thickness It is formed including a first surface and a second surface opposing each other with respect to the direction, and when the metal plate is composed of an alloy containing iron and nickel and a plurality of inclusions other than the iron and nickel, the metal plate The number of first inclusions with a size of less than 1㎛ included per 1㎣ of unit area is 25,000 or less.

The number of first inclusions with a size of less than 1㎛ included per 1㎣ of unit area of the metal plate may be 20,000 to 25,000.

The number of first inclusions with a size of less than 1㎛ included per 1㎣ of unit area of the metal plate may be 0 or more and 1,000 or less.

The number of first inclusions with a size of less than 1㎛ included per 1㎣ of unit area of the metal plate may be 10 to 300 or less.

The number of second inclusions with a size of less than 1 to 3 ㎛ included per 1㎣ of unit area of the metal plate may be 16,000 or less.

The number of second inclusions with a size of less than 1 to 3 μm included per 1㎣ of unit area of the metal plate may be 13,000 to 16,000 or less.

The number of second inclusions with a size of less than 1 to 3 ㎛ included per 1㎣ of unit area of the metal plate may be 1,000 or less.

The number of third inclusions with a size of 3 to 5㎛ included per 1㎣ of unit area of the metal plate may be 200 or more and 300 or less.

It may not include a fourth inclusion with a size exceeding 5㎛, which is included per 1㎣ of unit area of the metal plate.

The metal plate has an upper layer constituting 0 to 35% of the thickness t0 in the thickness direction from the first side, a lower layer constituting 0 to 35% of the thickness t0 in the thickness direction from the second side, and an interior between the upper layer and the lower layer. It may be formed including an intermediate layer that constitutes 35 to 60% of the thickness t0.

The number of first inclusions with a size of less than 1㎛ included per 1㎣ of unit area of the middle layer of the metal plate may be greater than the number of first inclusions included in the upper or lower layer of the metal plate.

One aspect of the method for manufacturing a deposition mask of the present invention for achieving the above technical problem is a method for manufacturing a deposition mask having an effective area in which a plurality of through holes are formed and a peripheral area located around the effective area. , a step of preparing a metal plate having a thickness t0 of 50 μm or less and including first and second surfaces facing each other in the thickness direction, a resist pattern forming step of forming a resist pattern on the metal plate, an etching process of etching the metal plate using the resist pattern as a mask to form the through hole in a region of the metal plate forming the effective area, wherein the metal plate is an alloy containing iron and nickel and the iron When the metal plate further includes a plurality of inclusions other than nickel, the number of first inclusions less than 1 μm in size per 1 mm3 unit area of the metal plate is 25,000 or less.

In the method of manufacturing the deposition mask, the number of first inclusions with a size of less than 1㎛ included per 1㎣ of unit area of the metal plate may be 20,000 to 25,000.

In the method of manufacturing the deposition mask, the number of first inclusions with a size of less than 1㎛ included per 1㎣ of unit area of the metal plate may be 0 or more and 1,000 or less.

In the method of manufacturing the deposition mask, the number of first inclusions with a size of less than 1 μm included per 1 mm3 of unit area of the metal plate may be 10 to 300 or less.

In the method of manufacturing the deposition mask, the number of second inclusions with a size of less than 1 to 3 μm included per 1 mm3 of unit area of the metal plate may be 16,000 or less.

In the method of manufacturing the deposition mask, the number of second inclusions with a size of less than 1 to 3 μm included per 1 mm3 of unit area of the metal plate may be 13,000 to 16,000 or less.

In the method of manufacturing the deposition mask, the number of second inclusions with a size of less than 1 to 3 μm included per 1 mm3 of unit area of the metal plate may be 1,000 or less.

In the method of manufacturing the deposition mask, the number of third inclusions with a size of 3 to 5 μm included per 1 mm3 of unit area of the metal plate may be 200 to 300.

In the method of manufacturing the deposition mask, the fourth inclusion with a size exceeding 5 μm included per 1 mm3 of unit area of the metal plate may not be included.

In the method of manufacturing the deposition mask, the metal plate has an upper layer constituting 0 to 35% of the thickness t0 in the thickness direction from the first side, and 0 to 35% of the thickness t0 in the thickness direction from the second side. It may be formed including a lower layer and an intermediate layer constituting 35 to 60% of the thickness t0, which constitutes the interior between the upper layer and the lower layer.

In the method of manufacturing the deposition mask, the number of first inclusions with a size of less than 1㎛ included per 1㎣ of unit area of the middle layer of the metal plate may be greater than the number of first inclusions included in the upper or lower layer of the metal plate.

In the method of manufacturing the deposition mask, the intermediate layer of the metal plate may be used as the effective area.

One side of the deposition mask of the present invention for achieving the above technical problem is a deposition mask having an effective area in which a plurality of through holes are formed and a peripheral area located around the effective area, and the effective area of the deposition mask is and the surrounding area are formed on a metal plate including a first surface and a second surface opposing each other with respect to the thickness direction, and the metal plate further contains an alloy containing iron and nickel and a plurality of inclusions other than the iron and nickel. When configured to include, the number of first inclusions with a size of less than 1㎛ included per 1㎣ of unit area of the metal plate is 25,000 or less.

In the deposition mask, the number of first inclusions with a size of less than 1㎛ included per 1㎣ of unit area of the metal plate may be 20,000 to 25,000.

In the deposition mask, the number of first inclusions with a size of less than 1㎛ included per 1㎣ of unit area of the metal plate may be 0 or more and 1,000 or less.

In the deposition mask, the number of first inclusions with a size of less than 1㎛ included per 1㎣ of unit area of the metal plate may be 10 to 300 or less.

In the deposition mask, the number of second inclusions with a size of less than 1 to 3 μm included per 1 mm3 of unit area of the metal plate may be 16,000 or less.

In the deposition mask, the number of second inclusions with a size of less than 1 to 3 μm included per 1 mm3 of unit area of the metal plate may be 13,000 to 16,000 or less.

In the deposition mask, the number of second inclusions with a size of less than 1 to 3 μm included per 1 mm3 of unit area of the metal plate may be 1,000 or less.

Specific details of other embodiments are included in the detailed description and drawings.

The present invention analyzes the inclusions contained inside the raw material, selects and manufactures a metal plate according to the analysis results of the inclusions, and manufactures a deposition mask using the metal plate manufactured in this way, thereby achieving the following effects. there is.

First, since it is possible to predict in advance whether a deposition mask is defective depending on the characteristic level of the metal plate, unnecessary waste of time and resources required to manufacture a defective deposition mask can be reduced.

Second, by improving the manufacturing yield of good-quality deposition masks, defects in OLED display products can be prevented in advance.

The effects of the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

1 is a flowchart sequentially explaining a method of selecting a metal plate having inclusion conditions suitable for manufacturing a metal mask according to an embodiment of the present invention.

Figure 2 is a conceptual diagram showing the schematic structure of an inclusion analysis system applied to a metal plate selection method according to an embodiment of the present invention.

FIG. 3 is a conceptual diagram showing the schematic structure of a filtration device constituting the inclusion analysis system of FIG. 2.

Figure 4 is an example diagram for explaining a method of measuring inclusions in an inclusion measuring device that constitutes an inclusion analysis system.

Figure 5 is a conceptual diagram showing the relationship between an inclusion analysis system and a control unit applied to the metal plate selection method according to an embodiment of the present invention.

Figure 6 is a reference diagram for further explaining the surface treatment method applied to the metal plate sorting method according to an embodiment of the present invention.

Figure 7 is a flowchart sequentially explaining a method of selecting a metal plate having inclusion conditions suitable for manufacturing a metal mask according to another embodiment of the present invention.

Figure 8 is a flow chart sequentially explaining a method of manufacturing a metal mask using a metal plate.

Figure 9 is a diagram showing the results of an experiment to set a management level for inclusions contained in a metal plate according to the first embodiment.

Figure 10 is a diagram showing the results of an experiment to set a management level for inclusions contained in a metal plate according to the second embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. The same reference numerals are used for the same components in the drawings, and duplicate descriptions thereof are omitted.

The present invention analyzes inclusions contained in a metal plate to select a metal plate with inclusion conditions suitable for manufacturing a deposition mask, and uses the selected metal plate as described above to manufacture a high-resolution display. It is characterized by manufacturing a deposition mask to be used. In the above, the metal plate used for inclusion analysis may be manufactured according to a rolling method. Additionally, the high-resolution display may be an Organic Light Emitting Diodes (OLED) display, for example, a display with a pixel density of 500ppi (pixels per inch) or more, or a display with a pixel density of 800ppi or more. Hereinafter, a metal mask will be described as an example of a deposition mask.

First, inclusions contained in the metal plate will be described.

The metal plate used to manufacture the metal mask may be made of an iron alloy containing iron and nickel. However, the metal plate may further contain particles other than iron, nickel, cobalt, etc. due to additives (e.g., aluminum, silicon, etc.) added to remove impurities during the melting process of manufacturing the base material of the metal plate. In the present invention, particles other than iron, nickel, cobalt, etc. contained in the metal plate are defined as inclusions.

When manufacturing a metal mask using a metal plate, inclusions contained in the metal plate may affect the manufacturing process of the metal mask. Specifically, the size of the inclusions can affect the manufacturing process of the metal mask, and the quantity of inclusions can also affect the manufacturing process of the metal mask.

When manufacturing a metal mask using a metal plate, the metal mask can be manufactured by etching the metal plate to form a plurality of through holes. Through holes can be used to form pixels in a desired pattern in the display.

However, if the size of the inclusions is larger than the appropriate size or the quantity of the inclusions is greater than the appropriate quantity, when the through hole is formed by etching, the inside of the metal plate is exposed by the through hole after etching, or the surface is etched and the metal plate As the inclusions remaining inside are separated from the metal plate and a pitted defect occurs, when forming a through hole in the metal plate, the shape of the through hole deviates from the designed value, and as a result, the through hole of the desired shape or the metal plate with the through hole is formed. It becomes impossible to form an appropriate level of durability (the level at which the metal plate can withstand the corresponding tensile force during the metal mask tensioning stage), and pixels cannot be formed in the desired pattern on the display.

Therefore, in the present invention, the size and quantity of inclusions included in the metal plate are analyzed to select a metal plate with inclusion conditions suitable for manufacturing a metal mask, and a metal mask can be manufactured using the selected metal plate.

Hereinafter, the present invention will be described in detail with reference to the drawings.

First, the process of selecting metal plates will be explained.

First, prepare a plurality of metal plates (S110). Here, each metal plate may be made of an alloy containing an iron component, a nickel component, a cobalt component, etc., and may be manufactured according to a rolling method. Additionally, each metal plate may be provided wound on a roll.

Each metal plate may have a predetermined thickness, preferably each metal plate may have a thickness of 50 μm or less (0 μm < thickness of metal plate ≤ 50 μm). More preferably, each metal plate may have a thickness of 30 μm or less (0 μm < thickness of metal plate ≤ 30 μm).

At this time, if the thickness of the metal plate exceeds 50㎛, it may be difficult to implement the specifications or shape of the through hole required for the metal mask applied to the high-resolution display. More specifically, in the case of a high-resolution display, the spacing between the plurality of through holes formed in the metal mask must be narrow, or the size of the through holes must be smaller than that of the metal mask applied to the low-resolution display. .

However, when forming a concave area (large hole or small hole) by etching one or both sides of a metal plate, not only is the concave area etched in the thickness direction of the metal plate, but also etching in the width direction is performed simultaneously, making it applicable to high-resolution displays. In the case of a metal mask, there is a problem that a desirable spacing or shape of the through holes cannot be formed because some adjacent concave areas or through holes overlap each other.

When a plurality of metal plates are prepared, samples are collected from each metal plate (S120), inclusions contained in the sample are analyzed, and the size and quantity of the inclusions are measured (S130).

In this embodiment, among the various components included in the sample, the remaining components excluding the iron component and nickel component can be defined as inclusions. Alternatively, the remaining components excluding the iron component, nickel component, and cobalt component may be defined as inclusions. The inclusion may be, for example, an aluminum component, a magnesium component, a silicon component, a phosphorus component, a sulfur component, a chromium component, a zirconium component, etc., and may also be a compound containing a plurality of components. Here, compounds are defined as including oxides, sulfides, carbides, nitrides, and intermetallic compounds.

When analyzing inclusions, an inclusion analysis system that can measure the size and quantity of inclusions from a sample can be used. Below, the inclusion analysis system will be described.

In the following description, a filtering system for filtering a plurality of

samples

210a, 210b, ..., 210n using a chemical solution 220 as an embodiment of the inclusion analysis system 200 will be described. According to FIG. 2, the inclusion analysis system 200 may include a chemical solution 220, a mixing container 230, a filtration device 240, and an inclusion measurement device 250.

The chemical solution 220 is a substance used to dissolve each

sample

210a, 210b, ..., 210n. Specifically, the chemical solution 220 may dissolve iron and nickel components and may not dissolve inclusions containing other components. Alternatively, the chemical solution 220 may dissolve the iron component, nickel component, and cobalt component, and may not dissolve inclusions containing other components. Inclusions are particles that are poorly soluble in the chemical solution 220, and the chemical solution 220 may be prepared as a solution containing, for example, a nitric acid component. Alternatively, it may be a solution containing sulfuric acid or hydrogen peroxide. The chemical solution 220 may be a solution containing other ingredients as long as it contains ingredients capable of dissolving iron and nickel.

The chemical solution 220 is introduced into the mixing container 230 together with each sample (210a, 210b, ..., 210n), and each sample (210a, 210b, ..., 210n) is dissolved to form each sample (210a, 210b). , ..., 210n) and a chemical solution (220) can be mixed to produce a mixture. When dissolving each

sample

210a, 210b, ..., 210n using the chemical solution 220, a magnetic material may be used. The magnetic material may be provided as, for example, a magnetic plate.

The filtration device 240 serves to filter the mixture and extract inclusions from the mixture. The filtration device 240 can extract inclusions from the mixture using vacuum filtration, but this embodiment is not necessarily limited to this method, and if inclusions can be effectively extracted from the mixture, vacuum filtration may be used. Other methods may also be used in this embodiment.

When the filtration device 240 is a device that filters a mixture using vacuum filtration, as shown in FIG. 3, it includes a first container 310, a filter 320, a second container 330, and a pressurization module 340. It may be configured to include.

The first container 310 is a container into which the mixture is added. The first container 310 may include a filter 320 on its inner bottom to filter the mixture, and a second container located below the first container 310 to accommodate the liquid separated from the inclusions by the filter 320. It can be connected to (330). The first container 310 may be provided as a funnel, for example, and a clamp may be used to fix the first container 310 on the second container 330.

The filter 320 may have micropores of uniform size formed in the membrane to filter the mixture. The filter 320 may be installed inside the first container 310 while being mounted on a metal mesh, and may be provided as a membrane filter having a mesh shape. The filter 320 and the fine holes can be selected and applied with appropriate sizes depending on the size of the

samples

210a, 210b, ..., 210n. For example, the filter 320 may have a size of 30 mm to 40 mm. Alternatively, the filter 320 may have a size of 40 mm to 50 mm. Additionally, the micropores may have a size of 0.2㎛ or less (0㎛<micropore size ≤0.2㎛). Alternatively, the micropores may have a size of 0.1㎛ or less (0㎛<micropore size ≤0.1㎛).

The maximum capacity that the second container 330 can accommodate may be larger than that of the first container 310. For example, the second container 330 may have a maximum capacity of 1000 ml, and the first container 310 may have a maximum capacity of 300 ml. However, this embodiment is not limited to this. The first container 310 and the second container 330 may have the same maximum capacity, and the first container 310 may have a larger maximum capacity than the second container 330.

The second container 330 may form a vacuum state inside the second container 330 while the mixture is filtered by the filter 320. The interior of the second container 330 may be connected to the pressurizing module 340 for this purpose, and may be provided as a bottle, that is, a filter bottle, for example.

The pressurizing module 340 serves to pressurize the interior of the second container 330. The pressure module 340 may be provided as a pressure gauge for this purpose, and may be connected to the inside of the second container 330 through a tube of a predetermined length. The pressurizing module 340 may be provided as, for example, a vacuum pump to form the interior of the second container 330 into a vacuum state.

This will be described again with reference to FIG. 2 .

The inclusion measuring device 250 serves to measure inclusions remaining on the filter 320. Filter 320 may be dried to remove moisture after filtering the mixture. When the filter 320 is completely dried, the inclusion measuring device 250 can measure the size and quantity of inclusions by observing the surface of the filter 320. The inclusion measuring device 250 may be provided, for example, with a scanning electron microscope (SEM) or an optical microscope. When the inclusion measuring device 250 is provided as a scanning electron microscope, the object may be a microscope with a magnification of 400 to 500 times. Alternatively, it is okay to apply a microscope that can observe the object to be measured at a higher magnification.

In the above, the filter 320 may be dried using a natural drying method to remove moisture, but may also be dried using a drying device to complete drying within a limited time. The filter 320 may be dried using, for example, a drying device that supplies hot air.

The inclusion measuring device 250 may divide the filter 320 into a plurality of regions and then calculate the size and quantity of inclusions for the entire area of the filter 320 based on the measurement results for each region.

For example, the filter 320 includes a first area 410, a second area 420, a third area 430, a fourth area 440, and a fifth area 450. , nine areas (410, 420, 430, 440, 450, 460, 470, 480, 490), including the sixth area (460), the seventh area (470), the eighth area (480), and the ninth area (490). ) can be divided into In this case, the inclusion measuring device 250 individually measures each of the nine areas (410, 420, 430, 440, 450, 460, 470, 480, 490), and based on the measurement results, the entire filter 320 The size and quantity of inclusions per area can be calculated.

For example, 5 to 50 points are designated for each area, each point is inspected with a scanning electron microscope to measure the size and quantity of inclusions in each area, and from there, the entire filter 320 is measured. The size and quantity of inclusions per area can be calculated. A point refers to an image unit observed by the inclusion measurement device 250. For example, when the inclusion measuring device 250 is provided with a scanning electron microscope, the point may be an image unit observed by the magnification of the scanning electron microscope. The point may have a size of, for example, 0.2mm ² to 1.0mm ² . The size of the point is not limited to the above range, and can be easily changed and applied depending on the size of the filter or the level of the sample extracted from the metal plate. Figure 4 is an example diagram for explaining a method of measuring inclusions in an inclusion measuring device that constitutes an inclusion analysis system.

However, it is not limited to this, and the inclusion measuring device 250 divides the filter 320 into a plurality of areas, selects several areas among them, measures the size and quantity of inclusions in the selected areas, and filters from there. It is also possible to estimate or convert the size and quantity of inclusions for the entire area of (320).

For example, select at least one region corresponding to an area of 5% to 10% of the total area of the filter 320, designate 5 to 50 points for the selected region, and examine each with a scanning electron microscope. By inspecting the point, the size and quantity of inclusions for the selected area can be measured, and from there, the size and quantity of inclusions for the entire area of the filter 320 can be estimated. However, when performing the above method, the inclusion measuring device 250 measures the size of the inclusions with respect to the entire area of the filter 320, assuming that the inclusions are uniformly distributed over the entire area of the filter 320. Quantity can be estimated.

The inclusion measuring device 250 is also capable of calculating the size and quantity of inclusions for the entire area of the filter 320 without dividing the filter 320 into a plurality of areas. For example, tens to hundreds of points can be designated in the entire area of the filter 320, and each point can be inspected using a scanning electron microscope to calculate the size and quantity of inclusions for the entire area of the filter 320. .

However, it is not limited to this, and the inclusion measuring device 250 selects a partial area from the entire area of the filter 320, measures the size and quantity of inclusions for the selected area, and measures the size and quantity of the inclusions in the selected area, It is also possible to estimate the size and quantity of inclusions. In this case as well, the inclusion measuring device 250 can estimate the size and quantity of inclusions for the entire area of the filter 320 under the premise that the inclusions are uniformly distributed over the entire area of the filter 320.

Description will be made again with reference to FIG. 1 .

After analyzing each sample (210a, 210b, ..., 210n) to measure the size and quantity of inclusions (S130), each metal plate was analyzed based on the analysis results for each sample (210a, 210b, ..., 210n). Sort into good and defective products (S140).

When classifying each metal plate as a good product or a defective product based on the analysis results for each sample (210a, 210b, ..., 210n) (S140), considering both the size and quantity of the inclusions, each metal plate is classified as a good product. It can be sorted into defective products. Alternatively, each metal plate can be sorted into good and defective products by considering only the size of the inclusions. Alternatively, each metal plate can be sorted into good and defective products by considering only the quantity of inclusions.

When classifying each metal plate as a good product or a defective product considering both the size of the inclusion and the quantity of the inclusion, if the size of the inclusion is less than the standard size and the quantity of inclusions of each size is less than the standard quantity, the metal plate is judged as a good product. can do.

When each metal plate is classified as a good product or a defective product considering only the size of the inclusion, if the size of the inclusion is less than the standard size, the metal plate can be judged as a good product.

When classifying each metal plate into a good product or a defective product considering only the quantity of inclusions, if the quantity of inclusions is less than the standard quantity, the metal plate can be judged as a good product.

Sorting each metal plate into good and bad products can be performed by the control unit. The control unit 500 is connected to the inclusion analysis system 200 as shown in FIG. 5, and receives analysis results for each

sample

210a, 210b, ..., 210n from the inclusion measurement device 250, respectively. Metal plates can be sorted into good and defective products. The control unit 500 may be provided as a computer or server to perform calculation tasks. Figure 5 is a conceptual diagram showing the relationship between an inclusion analysis system and a control unit applied to the metal plate selection method according to an embodiment of the present invention.

Meanwhile, as another embodiment of the present invention, the task of sorting a metal plate into a good product or a defective product based on the analysis results provided from the inclusion measuring device 250 can be performed using other means without applying the control unit 500. do. For example, it is possible to select good/defective metal plates by an operator. Based on the analysis results provided from the inclusion measuring device 250, the worker manually compares the inclusion standards described later and determines that the metal plate winding body from which a sample that satisfies the standards is a good product and can be used for manufacturing a metal mask, and thereafter It is also possible to apply it to the process.

After each metal plate is sorted into good products and defective products (S140), both sides of the metal plates selected as good products are surface treated (S150). In this case, both sides of the metal plate can be surface treated through a slimming operation, and the upper and lower layers can be removed from the metal plate so that the middle layer can be used as an effective area. In this embodiment, it is also possible to remove only one of the upper and lower layers from the metal plate. Additionally, the present embodiment is not limited to this, and if a metal plate of the final metal mask thickness level is prepared, the slimming operation may be omitted.

Inclusions included in the metal plate, depending on their size, are 1㎛ or less (size of inclusion ≤ 1㎛), greater than 1㎛ but less than 3㎛ (1㎛ < size of inclusion ≤ 3㎛), greater than 3㎛ and less than 10㎛ ( It can be classified as 3㎛ < size of inclusion ≤ 10㎛), greater than 10㎛ (size of inclusion > 10㎛), etc. As shown in FIG. 6, the metal plate is oriented in the height direction (i.e., in the third direction 30) between the upper layer (H Layer) constituting the upper surface, the lower layer (L Layer) constituting the lower surface, and the upper surface and lower surface. When divided into three layers, including the middle layer (M Layer) that constitutes the interior of The third inclusions 630 with a size of more than 10㎛, the fourth inclusions with a size of more than 10㎛ 640, etc. are distributed in a biased manner in the upper layer (H Layer) and lower layer (L Layer), and the middle layer (M Layer), the first inclusions 610 having a size of approximately 1㎛ or less are distributed.

Therefore, in this embodiment, taking this aspect of the metal plate into consideration, the upper layer (H Layer) and the lower layer (L Layer) can be removed from each metal plate (S150). When removing the upper layer (H Layer) and lower layer (L Layer) from a metal plate, an etching method may be used. However, this embodiment is not limited to this, and any method other than the etching method may be used as long as the upper layer (H Layer) and the lower layer (L Layer) can be effectively removed from the metal plate. Figure 6 is a reference diagram for further explaining the surface treatment method applied to the metal plate sorting method according to an embodiment of the present invention.

When surface treating both sides of a metal plate (S150), 0% to 35% of the total thickness can be removed from the upper surface as an upper layer (H Layer). Likewise, 0% to 35% of the total thickness can be removed from the lower surface as the lower layer (L Layer). In this case, 35% to 60% of the total thickness may remain as the middle layer (M Layer).

The thickness of the metal plate can be set to 30㎛ or less as previously described. Alternatively, the thickness of the metal plate may be 50㎛ or less. When the upper layer (H Layer) and the lower layer (L Layer) are each removed, the thickness of the middle layer (M Layer) can be formed to be 20㎛ (0㎛ < thickness of the middle layer (M Layer) ≤ 20㎛).

When surface treating both sides of a metal plate (S150), the upper and lower layers (H Layer) and lower layers (L Layer) can be removed through uniform etching of the upper and lower sides or asymmetric etching of the upper and lower sides, respectively. In addition, depending on the selective adjustment of the position and thickness of the effective area (i.e., the middle layer (M Layer)), the height direction thickness (t1) of the upper layer (H Layer), the height direction thickness (t2) of the middle layer (M Layer), and the lower layer The height direction thickness (t3) of (L Layer) may vary. Selective adjustment of the effective area may be due to the measurement results of the inclusion measurement device 250.

As an example, when manufacturing a metal mask described later among the upper layer (H Layer) and the lower layer (L Layer), more layers are added to the side where through holes (pores) corresponding to the glass substrate (corresponding to the display) are formed. It can be etched. This is because the distribution density of small-sized inclusions increases toward the inside of the metal plate, and according to multiple experiments and observation results, the size of the inclusions in the through holes corresponding to small holes has a greater influence on the shape of the hole during etching. am.

As described above, the control unit 500 can sort each metal plate into good and defective products (S140). The control unit 500 may determine that a metal plate meeting certain conditions is a good product based on the measurement results of the inclusion measurement device 250. However, it is not limited to this, and it is also possible for an engineer to collect a sample of a metal plate, filter and analyze inclusions, and then directly determine whether the sampled metal plate is good or bad.

The control unit 500 may determine the metal plate as a good product or a defective product by considering the size of the inclusion. In this case, the control unit 500 may determine that a metal plate containing only inclusions of a standard size or less is a good product. For example, the control unit 500 may determine that a metal plate containing only the first inclusion 610 is a good product. Alternatively, the control unit 500 may determine that a metal plate containing only the first inclusions 610 and the second inclusions 620 is a good product. Alternatively, the control unit 500 may determine that a metal plate including only the first inclusion 610, the second inclusion 620, and the third inclusion 630 is a good product. That is, the control unit 500 may determine that a metal plate that does not include the fourth inclusion 640 is a good product.

In the metal plate sorting process, the control unit 500 can determine the metal plate as good or defective by considering both the size and quantity of inclusions. In this case, the control unit 500 may determine that a metal plate that is less than the standard size or contains less than the standard number of inclusions is a good product.

Meanwhile, as described above in relation to the chemical solution, the chemical solution 220 can be selectively used to dissolve iron, nickel, and cobalt components and not dissolve inclusions containing other components. However, since the measurement results of inclusions may be different even for the same metal plate depending on the type of chemical liquid, optimized conditions for determining whether the metal plate is good or defective must be selected and applied depending on the type of chemical liquid.

The types of chemical solutions presented as examples below and the optimal conditions according to the types of chemical solutions were selected by the inventor of the present invention based on the results obtained through repeated experiments.

For example, when the first chemical solution is a chemical solution containing a sulfuric acid or hydrogen peroxide component, when mixed with the

samples

210a, 210b, ..., 210n, only the first inclusions 610 of less than 1㎛ are less than 25,000 per 1mm ³ . , Preferably, it is appropriate to select a metal plate containing 20,000 to 25,000 pieces or less as a condition for determining good quality. Alternatively, the first inclusions 610 of less than 1㎛ are included in the range of 20,000 to 25,000 per 1mm ³ and the second inclusions 620 in the range of 1㎛ to 3㎛ are included in the number of 13,000 to 16,000 or less per 1mm ³ It is appropriate to select a metal plate based on the conditions for determining good quality. Alternatively, the first inclusions 610 of less than 1㎛ are included in the range of 20,000 to 25,000 per 1mm ³ and the second inclusions 620 in the range of 1㎛ to 3㎛ are included in the number of 13,000 to 16,000 or less per 1mm ³ It is appropriate to select a metal plate containing less than 200 to 300 third inclusions 630 in the range of 3㎛ to 5㎛ per mm ³ as a condition for determining good products. Alternatively, the first inclusions 610 of less than 1㎛ are included in the range of 20,000 to 25,000 per 1mm ³ and the second inclusions 620 in the range of 1㎛ to 3㎛ are included in the number of 13,000 to 16,000 or less per 1mm ³ A metal plate containing 200 to 300 or less third inclusions 630 in the range of 3㎛ to 5㎛ per 1 mm ³ and not containing fourth inclusions 640 exceeding 5㎛ is a condition for determining a good product. It is appropriate to select

On the other hand, when a second chemical liquid different from the first chemical liquid (for example, a chemical liquid containing a nitric acid component) is mixed with the

samples

210a, 210b, ..., 210n, the first inclusions 610 of less than 1㎛ are 1mm. ³ It is appropriate to select metal plates containing less than 1,000 pieces per piece as a condition for determining good quality. Preferably, it is appropriate to select a metal plate containing 500 or less first inclusions 610 of less than 1㎛ per 1mm ³ as a condition for determining a good product. More preferably, it is appropriate to select a metal plate containing 10 to 300 first inclusions 610 of less than 1㎛ per 1mm ³ as a condition for determining good quality.

Alternatively, it is appropriate to select a metal plate containing 1,000 or less second inclusions 620 per 1 mm ³ in the range of 1㎛ to 3㎛ as a condition for determining a good product. Preferably, it is appropriate to select a metal plate containing 800 or less second inclusions 620 per 1mm ³ in the range of 1㎛ to 3㎛ as a condition for determining a good product.

Alternatively, it is appropriate to select a metal plate containing 500 or less second inclusions 620 of less than 2 ㎛ per 1 mm ³ as a condition for determining a good product. Preferably, it is appropriate to select a metal plate containing 500 or less second inclusions 620 per 1 mm ³ of 1 μm or more and less than 2 μm as a condition for determining a good product.

Alternatively, it is appropriate to select a metal plate containing 600 or less third inclusions 630 per 1 mm ³ in the range of 3 ㎛ to 5 ㎛ as a condition for determining a good product.

Alternatively, it is appropriate to select a metal plate containing 300 or less third inclusions 630 of less than 4 ㎛ per 1 mm ³ as a condition for determining a good product. Preferably, it is appropriate to select a metal plate containing 300 or less third inclusions 630 of 3 ㎛ or more and less than 4 ㎛ per 1 mm ³ as a condition for determining a good product.

However, it is not limited thereto, and the conditions for the first inclusion 610 of less than 1㎛, the conditions for the second inclusion 620 in the range of 1㎛ to 3㎛, and the second inclusion 620 of less than 2㎛ Conditions for, conditions for the second inclusion 620 of 1 ㎛ or more and less than 2 ㎛, conditions for the third inclusion 630 in the 3 ㎛ to 5 ㎛ range, third inclusion 630 of less than 4 ㎛ ), and the conditions for the third inclusion 630 of 3 μm or more and less than 4 μm, the metal plate can be determined to be a good product.

Meanwhile, the control unit 500 may determine the metal plate as a good product or a defective product by considering the quantity of inclusions. In this case, the control unit 500 may determine that a metal plate containing a standard number of inclusions of a specific size or less is a good product. For example, the control unit 500 may determine that a metal plate containing 20,000 to 25,000 or less first inclusions 610 per 1 mm ³ is a good product. Alternatively, the control unit 500 may determine that a metal plate containing 13,000 to 16,000 or less second inclusions 620 per 1 mm ³ is a good product. Alternatively, the control unit 500 may determine that a metal plate containing 200 to 300 or less third inclusions 630 per 1 mm ³ is a good product.

In the method of selecting a metal plate described above with reference to FIGS. 1 to 6, the metal plate is judged as either a good product or a defective product, and then the upper layer (H Layer) and the lower layer (L Layer) are removed from the metal plate and the middle layer (M Layer) is extracted. did. However, this embodiment is not limited to this. That is, in this embodiment, the upper layer (H Layer) and lower layer (L Layer) are removed from the metal plate, the middle layer (M Layer) is extracted, and then a sample is taken from the middle layer (M Layer) to classify the metal plate as either a good product or a defective product. It is also possible to determine.

Meanwhile, in the above embodiment, extracting the middle layer (M Layer) was explained as an example, but in a structure in which parts of the upper layer (H Layer) and lower layer (L Layer) remain at the top and bottom of the middle layer (M Layer), respectively, the sample It is also possible to collect.

First, prepare a plurality of metal plates (S710).

Afterwards, the upper layer (H Layer) and lower layer (L Layer) are removed from each metal plate to use the middle layer (M Layer) as the effective area (S720). At this time, as described above, according to the selective adjustment of the position and thickness of the effective area (i.e., the middle layer (M Layer)), the height direction thickness (t1) of the upper layer (H Layer) and the height direction thickness of the middle layer (M Layer) ( t2) and the height direction thickness (t3) of the lower layer (L Layer) may vary. Of course, it is also possible to apply asymmetric etching in which the removal levels of the upper and lower layers are different.

Afterwards, samples (210a, 210b, ..., 210n) are collected from the middle layer (M Layer) of each metal plate, and inclusions are detected for the samples (210a, 210b, ..., 210n) using the inclusion analysis system 100. Analyze and measure the size and quantity of inclusions (S730).

Thereafter, each metal plate is sorted into good and defective products using the control unit 500 (S740). The control unit 500 may determine that a metal plate meeting certain conditions is a good product based on the measurement results of the inclusion measurement device 250.

In this embodiment, as described above, the selection of good/defective metal plates is not limited to being performed by the control unit 500, but can also be performed manually, for example, by an operator. That is, the worker compares the pre-established inclusion standards based on the analysis results provided from the inclusion measuring device 250 and determines that the metal plate winding body from which the sample satisfying the standard is taken is a good product and can be used for manufacturing a metal mask, and thereafter Can be applied to the process.

In addition, as previously explained, before measuring the size and quantity of inclusions in the metal plate, the upper layer (H Layer) and lower layer (L Layer) can be removed from the metal plate through double-sided etching. However, this embodiment is not limited to this, and it is also possible to measure the size and quantity of inclusions for each metal plate after removing only one of the upper layer (H Layer) and lower layer (L Layer) through cross-sectional etching. do.

Meanwhile, a good quality metal plate selected according to an embodiment of the present invention may have a high distribution density of small-sized inclusions on one side where the cross-sectional etching has progressed more. In particular, a high distribution density of inclusions of less than 1 μm may be formed on one side of the metal mask in the direction in which small holes are formed.

Next, a method of manufacturing a metal mask using a metal plate will be described. Figure 8 is a flow chart sequentially explaining a method of manufacturing a metal mask using a metal plate. The following description refers to FIG. 8.

First, prepare a metal plate (S810). The metal plate may be manufactured and prepared according to the method described with reference to FIG. 5, and may also be manufactured and prepared according to the method described with reference to FIG. 7.

Afterwards, a mask-shaped metal foil (Metal Foil or Metal Leaf) is manufactured by casting the metal plate (S820). In this embodiment, it becomes possible to manufacture the metal foil into a thin film. For example, the thickness of the metal foil may be 50㎛ or less. Preferably, the thickness of the metal foil may be 30㎛ or less. More preferably, the thickness of the metal foil may be 10 μm to 18 μm or less.

Afterwards, a metal mask is manufactured by forming a plurality of through holes in the mask-shaped metal foil (S830).

The present invention relates to a metal plate for a metal mask and a method of manufacturing the same. The present invention also relates to a metal mask for OLED display devices and a method of manufacturing the same. In the present invention, in order to apply it to the production of high-resolution display products of 500ppi or more or 800ppi, the distribution of inclusions in the raw material, that is, the size and quantity of the inclusions from the surface to the inside are measured to derive the usable area (effective area), and the Based on the available area, metal plates for metal masks and metal masks for OLED displays can be manufactured sequentially.

In high-resolution display products, as the size of the inclusions increases, through holes cannot be formed normally in the metal mask. Even if the size of the inclusions is small, if the number is large, this can also have a negative impact on the mass production of the product. According to the present invention, when a metal plate is manufactured by rolling, it is possible to select a metal plate for pattern formation by analyzing the size and distribution of inclusions according to the thickness of the metal plate. Accordingly, a metal mask can also be manufactured using the selected metal plate. there is.

Figure 9 is a diagram showing the results of an experiment to set a management level for inclusions contained in a metal plate according to the first embodiment. And, Figure 10 is a diagram showing the results of an experiment to set the management level for inclusions included in the metal plate according to the second embodiment. Figure 9 exemplarily shows standards for determining a metal plate as a good product when the first chemical liquid is mixed with the samples (210a, 210b, ..., 210n), and Figure 10 shows a sample of a second chemical liquid different from the first chemical liquid. When mixed with (210a, 210b, ..., 210n), the standard for determining a metal plate as a good product is shown as an example.

This experiment was conducted by applying the inclusion analysis system and measurement device described above. An alloy metal plate SPL (size 7.6mm * 2.6mm * 30㎛) containing 1g of iron was dissolved in a chemical solution (220) and the inclusion analysis results were converted to 1㎣, and according to the experimental results in Figure 9 or 10, it was classified as a good product. When manufacturing a metal mask using the identified metal plate, it was possible to achieve the effect of improving defects caused by inclusions when manufacturing high-resolution products of 800ppi or higher.

Although embodiments of the present invention have been described above with reference to the attached drawings, the present invention is not limited to the above embodiments and can be manufactured in various different forms, and can be manufactured in various different forms by those skilled in the art. It will be understood by those who understand that the present invention can be implemented in other specific forms without changing its technical spirit or essential features. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive.

The present invention can be applied to the field of manufacturing a display device using a deposition mask.

Claims

It is a metal plate used to manufacture a deposition mask by forming a plurality of through holes,

The metal plate has a thickness t0 of 50 ㎛ or less and is formed including a first surface and a second surface that face each other in the thickness direction,

When the metal plate is composed of an alloy containing iron and nickel and a plurality of inclusions other than iron and nickel, the number of first inclusions less than 1㎛ in size per 1㎣ of the metal plate is 25,000. The metal plate below.
According to claim 1,

A metal plate in which the number of first inclusions less than 1㎛ in size per 1㎣ of unit area of the metal plate is 20,000 to 25,000.
According to claim 1,

A metal plate in which the number of first inclusions less than 1 μm in size per unit area of 1 ㎣ of the metal plate is 0 to 1,000.
According to claim 3,

A metal plate in which the number of first inclusions less than 1㎛ in size per 1㎣ of unit area of the metal plate is 10 to 300 or less.
According to claim 2 or 3,

A metal plate in which the number of second inclusions with a size of less than 1 to 3 μm included per 1㎣ of unit area of the metal plate is 16,000 or less.
According to claim 5,

A metal plate in which the number of second inclusions with a size of less than 1 to 3 μm included per 1㎣ of unit area of the metal plate is 13,000 to 16,000 or less.
According to claim 5,

A metal plate in which the number of second inclusions of less than 1 to 3 μm in size per 1㎣ of unit area of the metal plate is 1,000 or less.
According to claim 1,

A metal plate in which the number of third inclusions of 3 to 5 μm in size contained per 1㎣ of unit area of the metal plate is 200 to 300.
According to claim 1,

A metal plate that does not include fourth inclusions larger than 5 μm per unit area of the metal plate.
According to claim 1,

The metal plate has an upper layer constituting 0 to 35% of the thickness t0 in the thickness direction from the first side, a lower layer constituting 0 to 35% of the thickness t0 in the thickness direction from the second side, and an interior between the upper layer and the lower layer. A metal plate formed including an intermediate layer constituting 35 to 60% of the thickness t0.
According to claim 10,

A metal plate in which the number of first inclusions with a size of less than 1㎛ included per 1㎣ of unit area of the middle layer of the metal plate is greater than the number of first inclusions included in the upper or lower layer of the metal plate.
A method of manufacturing a deposition mask having an effective area in which a plurality of through holes are formed and a peripheral area located around the effective area,

A process of preparing a metal plate having a thickness t0 of 50 μm or less and including first and second surfaces facing each other in the thickness direction;

a resist pattern forming process of forming a resist pattern on the metal plate;

an etching process of etching the metal plate using the resist pattern as a mask to form the through hole in an area of the metal plate forming the effective area;

When the metal plate is composed of an alloy containing iron and nickel and a plurality of inclusions other than iron and nickel, the number of first inclusions less than 1㎛ in size per 1㎣ of the metal plate is 25,000. The following is a method of manufacturing a deposition mask.
According to claim 12,

A method of manufacturing a deposition mask in which the number of third inclusions of 3 to 5 μm in size included per 1㎣ of unit area of the metal plate is 200 to 300.
According to claim 12,

A method of manufacturing a deposition mask that does not include a fourth inclusion with a size exceeding 5㎛ included per 1㎣ of unit area of the metal plate.
According to claim 12,

The metal plate has an upper layer constituting 0 to 35% of the thickness t0 in the thickness direction from the first side, a lower layer constituting 0 to 35% of the thickness t0 in the thickness direction from the second side, and an interior between the upper layer and the lower layer. A method of manufacturing a deposition mask formed including an intermediate layer constituting 35 to 60% of the thickness t0.
According to claim 15,

A method of manufacturing a deposition mask in which the number of first inclusions with a size of less than 1㎛ included per 1㎣ of unit area of the middle layer of the metal plate is greater than the number of first inclusions included in the upper or lower layer of the metal plate.
The method of claim 15 or 16,

A method of manufacturing a deposition mask using an intermediate layer of the metal plate as the effective area.
A deposition mask having an effective area in which a plurality of through holes are formed and a peripheral area located around the effective area,

The effective area and the surrounding area of the deposition mask are formed on a metal plate including a first surface and a second surface opposing each other with respect to the thickness direction,

When the metal plate is composed of an alloy containing iron and nickel and a plurality of inclusions other than iron and nickel, the number of first inclusions less than 1㎛ in size per 1㎣ of the unit area of the metal plate is 25,000. Deposition mask below.