KR20170052468A - Metal mask material and metal mask - Google Patents

Abstract

The present invention provides a metal mask material and a metal mask which can improve etching processing accuracy and detect a defect with good precision. A metal mask material according to the present invention contains 30 to 45 mass% of Ni and Co in total, and 0 to 6 mass% of Co, and comprises a rolled foil of an Fe-Ni alloy composed of the remainder Fe and inevitable impurities. The thickness of the metal mask material (t) is 0.02 to 0.08 mm. The arithmetic mean roughness (Ra) measured in accordance with JIS-B 0601 in the direction parallel to the rolling direction and in the direction perpendicular to the rolling direction is 0.01 to 0.20 m. In addition, 60-degree gloss (G60) in accordance with JIS-Z 8741 in the direction parallel to the rolling direction and in the direction perpendicular to the rolling direction is 200 to 600.

Description

METAL MASK MATERIAL AND METAL MASK BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to a metal mask material and a metal mask used in the production of an organic EL display and the like.

Compared with a liquid crystal display, which is currently the mainstream among flat panel displays, an organic EL display can be made thinner due to its simple structure, has a smooth display of fast moving images, and has a wide viewing angle . This organic EL display has already been mass-produced by a small-sized device such as a portable terminal, and as a real name of a next-generation display, practical use in a large-sized display is progressing.

As a method of manufacturing the EL (light emitting) layer of the organic EL display, there are broadly divided into a vapor deposition method and a printing method. In the vapor deposition method, an EL material heated and evaporated in vacuum is adhered as a thin layer on the surface of a substrate. The printing method is a method in which an EL layer is formed on the surface of a substrate by printing. The deposition method also has a type that emits three colors of RGB (red-green) and a type that emits white light to the EL layer.

In the vapor deposition method, there is a color patterning step in which a metal mask is provided between an evaporation source and a substrate in order to fabricate the EL layer in a predetermined pattern on a predetermined position of the substrate. The metal mask is made of a metal plate or foil having an opening corresponding to the pattern of the EL layer. The EL material evaporated from the evaporation source and released into the vacuum reaches the metal mask, and the EL material having passed through the opening of the metal mask is attached to the substrate to become an EL layer having a predetermined pattern.

However, in the color patterning process, the temperature of the metal mask may rise to about 100 DEG C by adhering radiant heat from the evaporation source, and furthermore, an organic material having a high temperature to the surface of the metal mask, It is necessary to use a material having a thermal expansion equal to or less than that of the substrate to the metal mask. In particular, it is important to suppress the shift of the forming position due to the expansion of the metal mask, since the pattern of the EL layer in the type that emits three colors of R, G, and B needs to be formed every three colors of RGB.

The thickness of the metal mask is mainly 0.02 to 0.08 mm in the case of the three colors of R, G, and B, and 0.08 to 0.25 mm in the case of the type in which the EL layer is made to emit white light.

Another problem in the color patterning process of the type that emits three colors of R, G and B is that the positional shift of the organic material to be formed on the substrate occurs, and there arises a problem such as irregularity in color of the image. In this step, the organic material is deposited on the substrate through the opening of the metal mask from the vapor source at one point. Therefore, when the metal mask is thick, when the angle of incidence of the organic material at a position away from the evaporation source is low, the opening wall becomes a shadow, and the pattern shape of the organic material is formed into a shape different from the opening, It becomes difficult. This is called a shadowing effect and is improved by thinning the metal mask.

On the other hand, if the thickness of the metal mask is reduced in order to avoid the above problem, folding may occur at the time of handling, or an organic material may be deposited on the metal mask, and the weight may increase to cause distortion in the metal mask. In order to avoid such a problem, it is necessary to maintain the strength of the metal mask, and there is a limit in reducing the thickness.

As a method for achieving both the strength of the metal mask and the shape accuracy of the opening, there is proposed a technique of partially preventing the warpage of the thin metal mask by forming the reinforcing metal line (Patent Document 1) (See Patent Documents 2 and 3) in which a metal mask is formed by bonding a support layer made of a metal and a support having a star. Also disclosed is a technique (Patent Document 4) in which the surface roughness is controlled to improve the etching processing precision.

Japanese Patent Application Laid-Open No. 10-50478 Japanese Patent Publication No. 4126648 Japanese Patent Application Laid-Open No. 2004-039628 Japanese Patent Application Laid-Open No. 2010-214447

However, in the technique disclosed in Patent Document 1, since the organic material does not adhere to the shaded portion of the reinforcing metal wire, a phenomenon similar to the shadowing effect occurs, and the shape accuracy of the organic material formed on the substrate is deteriorated . Further, in the case of the techniques disclosed in Patent Documents 2 and 3, two metal foils are required for manufacturing one metal mask, and it is necessary to bond these metal foils with good precision, so that the process of forming the metal mask becomes complicated , Resulting in an increase in manufacturing cost.

As a solution to the above problem, there is known a method of forming the opening by thinning the periphery of the opening by half etching while using a material having a thickness enough to maintain the strength. As a result, the shadowing effect can be suppressed and the strength of the material can be ensured while using one sheet of metal foil, so that occurrence of warping due to adhesion of the organic material can be suppressed. Further, by making the openings by the etching method, the manufacturing cost can be reduced as compared with the case where masks (foils, plates) having predetermined apertures are directly formed by the plating method.

On the other hand, in the step of manufacturing a metal mask by a method such as etching from a metal mask material, the presence or absence of defects on the surface of the metal mask material is monitored with a naked eye or a CCD camera to remove the defective metal mask material from the process have.

In addition, the shielding deposited material is not deposited on the substrate other than the opening portion of the metal mask, but is cleaned and used repeatedly as a metal mask. The presence or absence of defects on the surface of the metal mask repeatedly used is also monitored with a naked eye or a CCD camera to remove the defective metal mask from the process.

Defects of the metal mask include foreign substances adhering to the surface, local discoloration and gloss defects, and microscopic ones that can not be confirmed by the naked eye due to these defects are inspected by an image obtained by enlarging the surface of the surface by a CCD camera or the like . Foreign matter having a color tone different from that of the metal mask material and local discoloration among the defects can be easily detected. Further, it is difficult to detect a foreign substance, for example, a metal piece having the same color tone as the metal mask material, as compared with a foreign substance having a different color tone or a local discoloration. In addition, the local gloss defect is unclear and the color tone is the same as the metal mask material, making it more difficult to identify on the CCD camera image.

Therefore, if the irregularities and the shape of the surface of the metal mask material are conspicuous, it is difficult to detect slight and weak defects such as local defective gloss as described above, even with a CCD camera image, With respect to this point, in the technology described in Patent Document 4, although the etching precision is improved by moderately roughening the surface roughness, the above-described local gloss defect described above can be corrected to a CCD camera image with good accuracy . ≪ / RTI >

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a metal mask material and a metal mask capable of improving the accuracy of etching processing and capable of detecting self-defects with good precision.

As a result of intensive studies conducted by the present inventors, it has been found that by controlling the 60 degree gloss (G60) in a predetermined range, it is possible to improve the etching processing precision and to provide a suitable surface irregularity capable of detecting self- I found out what I could do.

That is, the metal mask material of the present invention is a Fe-Ni alloy rolled foil containing 30 to 45 mass% of Ni and 0 to 5 mass% of Co in total and 0 to 6 mass% of Co and having the remainder Fe and inevitable impurities (T) of 0.02 to 0.08 mm, an arithmetic mean roughness (Ra) of 0.01 to 0.20 탆 measured according to JIS-B 0601 in the direction parallel to the rolling direction and in the direction perpendicular to the rolling direction and in the rolling parallel direction and in the direction perpendicular to the rolling direction The degree of gloss (G60) of 60 degrees measured in accordance with JIS-Z 8741 is 200 to 600.

The metal mask of the present invention is formed by using the metal mask material.

According to the present invention, it is possible to provide a metal mask material and a metal mask capable of improving the accuracy of etching processing and capable of detecting self-defects with good accuracy.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a diagram showing an optical microscopic image of a shape due to the division of crystal grains after finish rolling. Fig.

Hereinafter, the metal mask material according to the embodiment of the present invention will be described. Unless otherwise specified, "%" represents "% by mass".

(Alloy component)

Glass is used for the organic EL substrate, and it is necessary to adjust the alloy component so that the thermal expansion coefficient of the metal mask provided on the substrate is 10 x 10 < ^-6 > / DEG C or less. The coefficient of thermal expansion can be adjusted by adding Ni and / or Co to a predetermined concentration of Fe. Fe-Ni-based alloy containing Ni and Co in a total amount of 30 to 45% and Co of 0 to 6% Respectively. If the total concentration of Ni and Co and the concentration of Co deviate from this range, the thermal expansion coefficient of the metal mask becomes larger than the coefficient of thermal expansion of glass, which is not suitable. Preferably, Ni and Co are contained in a total amount of 34 to 38%, and Co is made 0 to 6%.

(thickness)

The thickness of the metal mask material of the present invention is 0.02 to 0.08 mm, preferably 0.02 to 0.04 mm. If the thickness of the metal mask material is less than 0.02 mm, the handling property is deteriorated and the metal mask is liable to be distorted or deformed by deposition of the organic material, so that the positional accuracy of the organic material formed on the substrate is lowered have. If the thickness of the metal mask material exceeds 0.08 mm, a shadowing effect may be remarkably generated.

(Arithmetic mean roughness (Ra))

The surface of the metal mask material of the present invention has an arithmetic mean roughness (Ra) of 0.01 to 0.20 mu m, preferably 0.01 to 0.08 mu m, measured according to JIS-B 0601 in the rolling parallel direction and in the direction perpendicular to the rolling direction. If the surface roughness is excessively reduced by setting Ra to less than 0.01 탆, the surface of the metal mask material is smooth. Therefore, the material guide rolls (the through-foil rolls and the through-plate rolls) of the line for producing the metal mask by etching from the metal mask material Slippage occurs and scratches are likely to occur. If Ra is excessively larger than 0.20 mu m and the surface roughness is excessively roughened, it becomes difficult to identify the contour on the CCD camera image, which is unclear and the color tone is the same as that of the metal mask material.

It is also preferable that the maximum height Ry of the surface of the metal mask material of the present invention measured in accordance with JIS-B 0601 in the rolling parallel direction and in the direction perpendicular to the rolling direction is 0.1 to 2.0 占 퐉.

(60 degree glossiness (G60))

(G60) measured in accordance with JIS-Z 8741 in the direction parallel to the rolling direction and the direction perpendicular to the rolling direction of the surface of the metal mask material of the present invention is 200 to 600, preferably 400 to 600. If the G60 of the metal mask material is less than 200, the unevenness and the shape of the surface become conspicuous, the outline becomes unclear, and it becomes difficult to detect the local gloss defect, which is the same color tone as the metal mask material, with the CCD camera image. If the G60 of the metal mask material exceeds 600, the surface becomes excessively smooth. Therefore, the surface control factor (for example, the shape and surface roughness of the roll, the viscosity of the rolling oil, The surface roughness of the metal mask material before rolling), it is difficult to ensure the uniformity of the surface, so that the appearance quality defect (for example, streaks or unevenness ) Is likely to occur.

(Manufacturing Method of Metal Mask Material)

The metal mask material of the present invention can be produced, for example, as follows, but is not intended to be limited to the following method.

First, the raw material is dissolved in a melting furnace to obtain a molten metal of the Fe-Ni-based alloy composition. At this time, if the oxygen concentration of the molten metal is high, the amount of the crystallized product such as oxides is increased to cause the etching failure. Therefore, the general deoxidation method, for example, the addition of carbon and the vacuum induction melting, And then cast into an ingot. After the hot rolling and the removal of the oxide layer by grinding, cold rolling and annealing are repeated to finish to a predetermined thickness. The cold rolling and the annealing can be sequentially performed, for example, intermediate recrystallization annealing, intermediate cold rolling, final recrystallization annealing, finish cold rolling and stress relieving annealing.

(Intermediate recrystallization annealing)

It is preferable to carry out recrystallization annealing in which the crystal grain size number (GS NO.) (Number specified by JIS G 0551 "Method for testing a steel-crystal grain size microscope") is 9.0 to 11.0. By increasing the crystal grain size number (GS NO.), A metal structure oriented with the final recrystallization annealing (200) is obtained. The metal structure oriented by the final recrystallization annealing 200 hardly forms the shape of the crystal grain in the finish cold rolling, and the 60 degree glossiness (G60) can surely be made 200 or more. If the crystal grain size number (GS NO.) Is small, that is, if the crystal grain size is large, the final recrystallization annealing may fail to obtain a sufficiently oriented metal structure. Therefore, the lower limit of the crystal grain size number GS NO. . On the other hand, if the crystal grain size number (GS NO.) Is too large, that is, if the crystal grains are too small, unrecrystallized portions may be dispersed in the recrystallized structure to cause uneven recrystallization structure in the final recrystallization annealing. The upper limit of the particle size number (GS NO.) Is 11.0.

Here, if the temperature of the intermediate recrystallization annealing is increased or the time is lengthened, the GS NO. Becomes lower, and the temperature is lowered or the time is shortened, GS NO. Lt; / RTI >

(Intermediate cold rolling)

It is preferable to carry out cold rolling with a working degree defined by the following formula at 85% or more.

(= (Plate thickness before rolling-plate thickness after rolling) / (plate thickness before rolling)} x 100 (%)

By increasing the degree of processing, the metal structure oriented with the final recrystallization annealing (200) is obtained, and the 60 degree gloss (G60) is increased as described above. If the degree of processing is small, the final recrystallization annealing may fail to obtain a sufficiently oriented metal structure. Therefore, the lower limit of the degree of processing is set to 85%. On the other hand, if the degree of processing is too high, the degree of orientation of (200) in the final recrystallization annealing does not increase further, and the hardness increases and the productivity decreases.

(Final recrystallization annealing)

Even in the final recrystallization annealing, when the recrystallization annealing is performed so that the crystal grain size number (GS NO.) Is 9.0 to 11.0, the 60-degree glossiness (G60) can surely be set to 200 or more for the same reason as in the intermediate recrystallization annealing can do.

(Finish cold rolling)

The surface properties (arithmetic mean roughness (Ra) and 60 degree gloss (G60)) of the metal mask material change depending on the surface irregularities generated by the finish cold rolling. In the finish cold rolling, the surface of the rolled roll is transferred to the material to form surface irregularities. Further, rolling oil flows into the rolling roll and the material in the finish cold rolling, and surface irregularities are produced by the generation of oil pits. In short, there is an oil film between the rolled roll and the material, and the contact between the rolled roll and the material becomes insufficient at the locally thick part of the oil film, and the texture of the rolled roll is not transferred and the concave and the convex on the pit become the oil pit. The cause of locally thickening of the rolling oil is the unevenness of the surface of the rolling roll and the deviation of workability of the material. In particular, when the surface is smoothed, the sensitivity of the influence of the deviation increases, and the thickness of the oil film is likely to vary.

Further, the crystal grains are divided and formed by finishing cold rolling, and the degree of 60 degree gloss (G60) is greatly influenced.

Fig. 1 shows an optical microscopic image of a shape resulting from the division of crystal grains after finishing cold-rolling. The shape by the crystal grain division is intermittently distributed in a row along the rolling direction RD and each shape is a stripe shape extending in the direction crossing the rolling direction RD as indicated by an arrow in Fig. In Fig. 1, two distinct rows (two rows) are formed along the rolling direction RD.

Here, the symbol G in Fig. 1 represents one grain on the ellipse extending in the rolling direction RD by cold rolling. It can be seen that the divided shape is formed inside the crystal grains G.

In Fig. 1, since the focal point on the optical microscope is matched to the grain segmentation shape, surface irregularities such as oil pits and transfer rolls of the rolling rolls having greatly different grain segment shapes and focal positions are not shown in Fig.

Since the cold rolling of foil is carried out at a high cost from the viewpoint of productivity, the crystal grains are elongated and are likely to be divided. As shown in Fig. 1, the divided crystal grains appear on the surface, resulting in a decrease in the degree of gloss (G60) of 60 degrees.

Herein, the susceptibility of the crystal grains to the breakage is affected by the orientation of the crystal grains and is different from that which is likely to be divided by the orientation of the crystal grains. This is because the deformability of the crystal differs depending on the crystal orientation. The major diffraction peaks in the alloy system of the metal mask material of the present invention are (200) plane, (220) plane, (311) plane and (111) plane, it's difficult. Therefore, by orienting the (200) plane by the intermediate recrystallization annealing and the final recrystallization annealing as described above, the crystal grain is hardly divided by finishing cold rolling, and the 60 degree glossiness (G60) can be made 200 or more.

It is preferable that the degree of finish cold rolling is 70% or more. The higher the degree of processing, the smaller the shape of the grain divided by the finish cold rolling due to the effect of compression processing, and the higher the degree of glossiness at 60 degrees (G60). On the other hand, even if the degree of processing is too high, the effect of weakening the shape of the divided parts of the crystal grains due to compression processing is saturated, and the hardness is increased and the productivity is lowered.

Here, cold rolling is carried out by using a rolling roll having a small diameter as much as possible, so that mixing of the rolling oil is reduced and the surface of the rolled material is smoothed. That is, the use of a roll having a small diameter can suppress the generation of oil pits and can reduce the shape of the divided portions of the crystal grains. In addition, as with the rolling roll diameter, by reducing the rolling speed, mixing of the rolling oil is reduced, and the surface of the rolled material is smoothed. That is, it is possible to suppress the occurrence of oil pits and to reduce the shape of the crystal grain breakage as long as the rolling speed is set to a low speed.

The diameter and the rolling speed of the rolling roll for cold rolling vary depending on the thickness and width of the metal mask material to be produced and the diameter and the rolling speed of the rolling roll can be appropriately set within a range in which Ra and G60 can be controlled. The rolling speed may be set to 60 m / min or less.

Since the shapes of the oil pits and the grain refinement are generated by different factors, it is preferable to set the production conditions capable of suppressing both the oil pits and the shape of the crystal grain breakage while confirming the occurrence situation.

(Stress relieving annealing)

Finally, stress relieving annealing is preferably performed at 200 to 400 ° C. The stress relieving annealing time can be, for example, 1 to 24 hours.

Example

Hereinafter, embodiments of the present invention will be described, but these are provided for better understanding of the present invention and are not intended to limit the present invention.

(1) Production of metal mask material

A raw material in which 36 mass% of Ni was added to Fe was dissolved by vacuum induction melting to cast an ingot having a thickness of 50 mm. This was subjected to hot rolling to 8 mm and the oxide film on the surface was removed by grinding, and then cold rolling and annealing were repeated to form a cold rolled steel sheet. Thereafter, intermediate recrystallization annealing, intermediate cold rolling, final recrystallization annealing, And the finish cold rolling were sequentially carried out to finish with the metal mask material of the product thicknesses of Examples 1 to 8 and Comparative Examples 1 to 4 in Table 1. [ Further, stress relieving annealing was performed at 300 캜 for 12 hours. Further, a composition having Fe of 31% by mass of Ni and 5% by mass of Co was added as the Example 9. The manufacturing process of the ninth embodiment is the same as the other embodiments.

The crystal grain size number (GS NO.) In the intermediate recrystallization annealing was 10.0. The surface roughness of the rolling roll was adjusted for each of the examples so that the arithmetic average roughness (Ra) of the product surface was 0.07 to 0.08 (0.065 to 0.084).

The following evaluations were carried out on the metal mask materials of the Examples and Comparative Examples after the stress relieving annealing.

(1) Arithmetic mean illuminance (Ra)

And measured as described above. The measurement was carried out by using a contact type surface roughness meter (SE-3400 manufactured by Kosaka Laboratory Co., Ltd.), and an average value measured by n ≥ 3 was obtained.

(2) 60 degree gloss (G60)

And measured as described above. For the measurement, the average value measured at n ≥ 3 was determined using a handy gloss meter PG-1 manufactured by Nippon Denshoku Kogyo Co.,

(3) The presence or absence of a measurement of surface defects

Surface defects in five steps were intentionally created for each metal mask material in each of Examples and Comparative Examples, and surface defects were measured with a CCD camera.

Specifically, an acid resistant tape of 50 mm x 50 mm was attached to the surface of each metal mask material, and an opening of 10 mm x 10 mm was formed at the center thereof to partially expose the surface. The exposed portions were coated with the following five kinds of etching solutions to form surface irregularities to form surface defects. This exposed portion was regarded as a reference surface defect because the exposed portion can be visually confirmed to be blurred as compared with the surroundings.

The etchant was prepared by using a solution prepared by directly using an aqueous solution of ferric chloride of 47 bomen and diluted with water at 2 times, 4 times, 8 times, and 16 times, respectively, and supporting the wafer with the tweezers, The parts were rubbed with cotton for 15 seconds. After the etching, the etching solution was wiped off with a cloth impregnated with water, and the acid-resistant tape was removed and the operation was completed. Also, the use of the aqueous ferric chloride solution for etching without diluting completely lost the metallic luster of the exposed portion, resulting in white, and the fog of the exposed portion became weaker as the dilution rate increased. When the dilution ratio was 32, the blur of the exposed portion could not be visually confirmed, so that the surface defect was not formed and the dilution ratio was up to 16 times. Therefore, in the etching with the above-described five types of etching solutions, surface defects confirmed by the naked eye are formed, and they are inherently to be detected as surface defects by the CCD unless they are affected by the surface irregularities of the metal mask material.

Next, pixel data of 256 gradations (± 128) were photographed by the CCD camera on the above-described five kinds of surface defects. Here, the state in which the reflected light was shut off was regarded as the reflection of the outermost layer and set to -128 in brightness, and the reflection from the top (the portion around the exposed portion) on the surface of the metal mask material was set to ± 0. The reflection that falls within the brightness range of ± 20 is defined as the normal reflection at the top, and the reflection that deviates from the range of the brightness of ± 20 is defined as the abnormal reflection in the surface defect. And it was confirmed whether or not it could be detected.

When the above-described five kinds of surface defects were detected for all the metal mask materials of the examples and comparative examples as "no measurement of surface defects was found", and at least one type of surface defects And the case where it was not detected was judged as " the measurement of the surface defect was wrong ".

As is apparent from Table 1, in each of Examples where Ra was 0.01 to 0.20 mu m and G60 was 200 to 600, no measurement of surface defects occurred.

On the other hand, in the case of Comparative Example 1 in which the finishing cold rolling processability is less than 70% and Comparative Example 2 in which the rolling speed of finish cold rolling exceeds 60 m / min, G60 becomes less than 200, Respectively.

In the case of Comparative Example 3 in which the final recrystallization annealing was performed under the condition that the crystal grain size (GS NO.) Of the final recrystallization annealing was less than 9.0 and in Comparative Example 4 in which the degree of processing of the intermediate cold rolling was made less than 85% 200, and a measurement error of the surface defect occurred.

Claims (2)

And a rolled foil of an Fe-Ni-based alloy containing 30 to 45% by mass of total of Ni and Co and 0 to 6% by mass of Co, the balance being Fe and inevitable impurities,
The thickness t is 0.02 to 0.08 mm,
An arithmetic mean roughness (Ra) measured in accordance with JIS-B 0601 in the direction parallel to the rolling direction and the direction perpendicular to the rolling is 0.01 to 0.20 탆,
A metal mask material having a degree of 60 degree gloss (G60) of 200 to 600 measured in accordance with JIS-Z 8741 in the rolling parallel direction and in the direction perpendicular to the rolling direction. A metal mask using the metal mask material according to claim 1.

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