Metal mask, method for forming an internal electrode pattern of a multilayer ceramic capacitor, method for forming an internal electrode of a multilayer ceramic capacitor, method for manufacturing a multilayer ceramic capacitor, and method for managing a metal mask for forming an internal electrode of a multilayer ceramic capacitor.

Abstract

This is a metal mask for manufacturing an internal electrode of a multilayer ceramic capacitor, wherein a rectangular through hole is formed in a metal substrate when viewed from a planar perspective. The dimension of the through-hole portion in the direction of the rectangular short side when viewed from a planar perspective is 300 μm or less. In the cross-sectional shape of the perimeter edge facing the through-hole portion, a step height is formed on the first side in the thickness direction of the substrate, and a tapered portion is formed on the second side in the thickness direction, extending away from the through-hole portion. The dimension of the step height in the thickness direction located in the short side direction is 12.2 μm or less. The tapered portion located in the short side direction has a taper angle of 47.0° or less relative to the short side direction.

Description

Technology Field

[0001] The present invention relates to a metal mask, a method for forming an internal electrode pattern of a multilayer ceramic capacitor, a method for forming an internal electrode of a multilayer ceramic capacitor, a method for manufacturing a multilayer ceramic capacitor, and a method for managing a metal mask for forming an internal electrode of a multilayer ceramic capacitor.

[0002] The present application claims priority based on Japanese Patent Application No. 2024-145739 filed in Japan on August 27, 2024, and Japanese Patent Application No. 2024-145117 filed in Japan on August 27, 2024, and incorporates the contents thereof herein. Background Technology

[0003] A Multilayer Ceramic Capacitor (MLCC) is a chip component type capacitor in which internal electrodes and dielectric sheets (often referred to as green sheets) are stacked in multiple layers. While MLCCs are becoming smaller, it has also become necessary for them to possess sufficient capacitance as capacitors. To increase capacitance without increasing the size, it is necessary to thin the film thickness of the internal electrodes and increase the number of layers. Conventionally, screen printing has been used for forming internal electrodes, but by using a sputtering method, it is possible to deposit the internal electrodes thinly and increase the number of layers compared to conventional methods.

[0004] One method for manufacturing a metal mask used in sputtering or vacuum deposition is to manufacture it by wet etching a thin metal substrate (see, for example, Patent Document 1). The material ejected from the target passes through a through hole formed by etching, thereby forming a film of a predetermined size and shape at a predetermined location. Prior art literature

[0005] Japanese Patent Publication No. 5382259 The problem to be solved

[0006] In the film deposition method described above, the film material is also deposited on the metal mask. If the film material is deposited near the through holes in the metal mask, the film deposition of the internal electrode is inhibited, which may cause the shape of the internal electrode to deteriorate, such as the line width becoming thinner. In addition, if the film material is deposited near the through holes in the metal mask, the film deposition of the internal electrode is inhibited, which may cause the film thickness to decrease and the film deposition efficiency (film deposition rate) to deteriorate.

[0007] If the shape of the internal electrode deteriorates, a problem arises in which the effective area of ​​the electrode decreases, leading to a reduction in electrical capacitance. Furthermore, if the number of cleaning cycles for the deposited film on the metal mask is increased to resolve the above problem, a problem arises in that the time until the metal mask is discarded is shortened.

[0008] The shape of the internal electrode strongly reflects the cross-sectional shape of the periphery edge of the through hole in the metal mask. In addition, the film thickness of the internal electrode strongly reflects the cross-sectional shape of the periphery edge of the through hole in the metal mask.

[0009] Indicators that characterize the cross-sectional shape of a metal mask include step height and taper angle.

[0010] The inventors have completed the present invention by examining the cross-sectional shape of the metal mask in various ways from the above perspective.

[0011] Based on the above circumstances, the present invention aims to provide a metal mask capable of forming an internal electrode with good internal electrode shape and good electrical characteristics, a method for forming an internal electrode pattern of a multilayer ceramic capacitor, a method for forming an internal electrode of a multilayer ceramic capacitor, and a method for manufacturing a multilayer ceramic capacitor.

[0012] In addition, based on the above circumstances, the present invention aims to provide a metal mask capable of forming an internal electrode with good electrical characteristics and a good film deposition rate, a method for forming an internal electrode pattern of a multilayer ceramic capacitor, a method for forming an internal electrode of a multilayer ceramic capacitor, and a method for manufacturing a multilayer ceramic capacitor.

[0013] Another objective of the present invention is to provide a method for managing a metal mask for forming internal electrodes of a multilayer ceramic capacitor, which can extend the period until the metal mask is discarded. means of solving the problem

[0014] A first embodiment of the present invention is a metal mask for manufacturing an internal electrode of a multilayer ceramic capacitor, wherein a rectangular through hole is formed in a metal substrate when viewed from a planar view, wherein the dimension of the through portion in the direction of the rectangular short side when viewed from a planar view is 300 μm or less, and in the cross-sectional shape of the perimeter edge facing the through portion, a step height is formed on the first side in the thickness direction of the substrate, and a tapered portion is formed on the second side in the thickness direction extending away from the through portion, wherein the dimension of the step height in the thickness direction located in the short side direction is 12.2 μm or less, and the tapered portion located in the short side direction has a taper angle with respect to the short side direction of 47.0° or less.

[0015] A second aspect of the present invention is a method for forming an internal electrode pattern of a multilayer ceramic capacitor, comprising forming the internal electrode by a physical vapor phase growth method using a metal mask of the first aspect.

[0016] A third aspect of the present invention is a method for forming an internal electrode of a multilayer ceramic capacitor, comprising forming the internal electrode using the method for forming an internal electrode pattern of the multilayer ceramic capacitor of the second aspect.

[0017] A fourth aspect of the present invention is a method for manufacturing a multilayer ceramic capacitor, comprising forming an internal electrode using the method for forming an internal electrode of a multilayer ceramic capacitor of a third aspect.

[0018] A fifth aspect of the present invention is a method for managing a metal mask for forming an internal electrode of a multilayer ceramic capacitor, comprising managing the upper limit of the thickness direction dimension of a deposited film on the metal mask of the first aspect to be 15 μm, and cleaning the metal mask when the thickness direction dimension of the deposited film reaches the upper limit.

[0019] A sixth aspect of the present invention is a metal mask for manufacturing an internal electrode of a multilayer ceramic capacitor, wherein a rectangular through hole is formed in a metal substrate when viewed from a planar view, wherein the dimension of the through hole in the direction of the rectangular short side when viewed from a planar view is 300 μm or less, and in the cross-sectional shape of the perimeter edge facing the through hole, a step height is formed on the first side in the thickness direction of the substrate, and a tapered portion is formed on the second side in the thickness direction extending away from the through hole, wherein the dimension of the step height in the thickness direction located in the short side direction is 8.3 μm or less, and the tapered portion located in the short side direction has a taper angle with respect to the short side direction of 50.2° or less.

[0020] A seventh aspect of the present invention is a method for forming an internal electrode pattern of a multilayer ceramic capacitor, comprising forming the internal electrode by a physical vapor phase growth method using a metal mask of the sixth aspect.

[0021] The eighth aspect of the present invention is a method for forming an internal electrode of a multilayer ceramic capacitor, comprising forming the internal electrode using the method for forming an internal electrode pattern of the multilayer ceramic capacitor of the seventh aspect.

[0022] A ninth aspect of the present invention is a method for manufacturing a multilayer ceramic capacitor, comprising forming an internal electrode using the method for forming an internal electrode of the multilayer ceramic capacitor of the eighth aspect.

[0023] The 10th embodiment of the present invention is a method for managing a metal mask for forming an internal electrode of a multilayer ceramic capacitor, comprising managing the upper limit of the thickness direction dimension of the deposited film on the metal mask of the 6th embodiment to 15 μm, and cleaning the metal mask when the thickness direction dimension of the deposited film reaches the upper limit. Effects of the invention

[0024] According to the present invention, a metal mask capable of forming an internal electrode with good shape and good electrical characteristics, a method for forming an internal electrode pattern of a multilayer ceramic capacitor, a method for forming an internal electrode of a multilayer ceramic capacitor, and a method for manufacturing a multilayer ceramic capacitor can be provided.

[0025] According to the present invention, a method for managing a metal mask for forming internal electrodes of a multilayer ceramic capacitor can be provided, which can extend the period until the metal mask is discarded. Brief explanation of the drawing

[0026] Figure 1 is a schematic diagram showing the positional relationship of a metal mask, etc., during the casting of the tabernacle. Figure 2 is a diagram showing the relationship between the cross-sectional shape of the metal mask through-hole and the film. Figure 3A is an example of a thickness profile of a nickel film. Figure 3B is an example of a thickness profile of a nickel film. FIG. 4 is a schematic plan view showing an example of a member formed using a metal mask related to the present embodiment. FIG. 5 is a schematic plan view showing another example of a member formed using a metal mask related to the present embodiment. FIG. 6 is a schematic plan view showing the positional relationship when the members of FIG. 4 are alternately stacked after being divided into two equal parts, or after cutting off the end of either the left or right side shown in FIG. 5. Specific details for implementing the invention

[0027] Hereinafter, embodiments of the metal mask of the present invention, a method for forming an internal electrode pattern of a multilayer ceramic capacitor, a method for forming an internal electrode of a multilayer ceramic capacitor, a method for manufacturing a multilayer ceramic capacitor, and a method for managing a metal mask for forming an internal electrode of a multilayer ceramic capacitor will be described with reference to FIGS. 1 to 6.

[0028] Furthermore, the following embodiments represent one aspect of the present invention and are not intended to limit the invention, and may be modified arbitrarily within the scope of the technical concept of the present invention.

[0029] The metal mask (1) related to the present embodiment is installed to overlap a dielectric sheet (often called a green sheet) (100) as a substrate, as schematically shown in FIG. 1. In processes such as physical vapor deposition sputtering or vacuum deposition, among the materials flying from the target (T) toward the metal mask (1), only those that pass through the through hole (1a) are deposited on the dielectric sheet (100) and formed as a conductive film thin film (101) (see FIG. 2). The material constituting the conductive film may be selected as a metal. As for the metal, for example, nickel, or a nickel alloy with nickel as the main component including aluminum, silver, copper, platinum, etc., may be used.

[0030] FIG. 2 is a cross-sectional view showing an enlarged view of one through hole (1a) in a metal mask (1). The through hole (1a) is formed by etching a sheet-shaped metal substrate (hereinafter simply referred to as "substrate (110)") constituting the metal mask from both sides in the thickness direction.

[0031] When a through hole (1a) is formed by wet etching, the etching is often performed in two stages. Specifically, the through hole (1a) is formed by first etching the surface (110a) on the side that is in contact with the dielectric sheet of the substrate (110), and then etching the surface (110b) on the target (T) side of the substrate (110). The surface (110a) corresponds to the first side in the thickness direction of the substrate (110). The surface (110b) corresponds to the second side in the thickness direction of the substrate (110).

[0032] Since etching is isotropic, the dimensions of the through hole (1a) when viewed from the plane are larger the closer they are to the surface (110a, 110b) of the substrate (110) and smaller as they move away from the surface (110a, 110b) of the substrate (110). Therefore, when manufacturing the metal mask (1), if two-stage etching is performed from the surface (110a, 110b) of the substrate (110), the dimensions of the formed through hole when viewed from the plane are smallest at the through portion (1b) in the middle of the thickness direction of the substrate (110), and the shape and dimensions when viewed from the plane at this portion define the shape of the film structure when viewed from the plane.

[0033] Since the penetration portion (1b) that has the smallest dimension when viewed from a plane is formed at the area where etching from the surface (110a, 110b) strikes, the position of the penetration portion (1b) in the thickness direction (hereinafter simply referred to as the “thickness direction”) of the substrate (110) changes depending on how much etching is performed from each surface.

[0034] Since the film material flies radially from the target (T), if it enters the penetration hole (1a) at an angle, as indicated by the dashed arrow (Ta) in FIG. 2, there is a possibility that it will fly out of the penetration area (1b) when viewed from a plane and reach the dielectric sheet (100). This phenomenon is sometimes referred to as the "shadow effect," and the probability of its occurrence increases as the penetration area (1b) moves further away from the dielectric sheet (100), that is, as the step height (h1) (details to be described later), which is the thickness dimension from the surface (110a) of the substrate (110) to the penetration area (1b), increases. And as the shadow effect becomes stronger, the upper surface area of ​​the formed film (101) becomes smaller than the lower surface area of ​​the formed film (101). That is, the formed thin film (101) has edges that are thinner than the center.

[0035] Meanwhile, as indicated by the dashed arrow (Tb) in FIG. 2, there is a possibility that it may fly out from outside the range of the penetration area (1b) when viewed from a planar perspective and reach the dielectric sheet (100). This phenomenon occurs due to a tapered portion (h2) formed on the surface (110b) side rather than the penetration area (1b) in the substrate (110). The tapered portion (h2) extends in a direction that moves away from the penetration area (1b) and increases the gap as it moves from the penetration area (1b) toward the surface (110b). The probability of the phenomenon occurring where the penetrating portion (1b) is flung out of the range of the penetrating portion (1b) when viewed from a planar perspective and reaches the dielectric sheet (100) increases as the position where the tapered portion (h2) opens on the surface (110b) moves further away from the penetrating portion (1b) and the tapered angle (θ) becomes smaller, and the formed thin film (101) becomes thicker.

[0036] The taper angle (θ) of the taper portion (h2) is the smaller of the angles of intersection between the line segment connecting the position where the taper portion (h2) opens to the surface (110b) and the penetration portion (1b) and the surface (110b) in the cross-sectional shape of the perimeter edge facing the penetration hole (1a).

[0037] In short, the metal mask (1) is configured to influence the shape and thickness of the thin film (101) in the cross-sectional shape of the perimeter edge facing the through hole (1a), such that a step height (h1) is formed on the surface (110a) side in the thickness direction and a tapered portion (h2) is formed on the surface (110b) side in the thickness direction.

[0038] Based on this, the inventors examined the step height (indicated by the symbol h1 in FIG. 2), which is the distance from the surface (110a) that adheres to the dielectric sheet (100), which is the substrate, in the thickness direction of the metal mask (1) to the penetration portion (1b), and the tapered portion (h2) located in the short direction, and examined the conditions of a metal mask desirable for manufacturing an internal electrode for an MLCC. In addition, the inventors examined the influence of the film formed by the film material flying from the target (T) being deposited on the surface (110b) and the tapered portion (h2) of the substrate (110), and examined the conditions of a metal mask desirable for manufacturing an internal electrode for an MLCC. Here, the short direction is a direction extending perpendicularly to the ground of FIG. 2 at both ends of the left-right direction (long direction) in the penetration hole (1a) of FIG. 2.

[0039] Examples

[0040] (Manufacturing of metal mask samples)

[0041] As a substrate, a stainless steel SUS430 sheet with a thickness of 50 μm (dimensions 350 mm × 715 mm when viewed from a flat surface) was prepared.

[0042] In the substrate, etching was performed on both sides using a two-step etching process to produce a number of rectangular through holes at a constant pitch when viewed from a planar perspective. The dimensions of the through portion (1b) in the short side direction were set to 300 μm.

[0043] At that time, metal mask samples of samples 1 to 8 having step heights and taper angles as shown in Table 1 were prepared by changing the etching amount from both sides. Likewise, metal mask samples of samples 1A to 7A having step heights and taper angles as shown in Table 3 were prepared by changing the etching amount from both sides.

[0044] After each sample was completed, the step height was measured by laser confocal scanning using a measuring device (VK-X200 manufactured by Keyence) in a state where the metal mask was cut in the longitudinal direction beyond the through hole and the thickness dimension of the step height located in the short side direction could be observed from the side of the through hole. The taper angle was also measured by laser confocal scanning using a measuring device (VK-X200 manufactured by Keyence) in the same manner from the surface (110b) side of the non-target side of the target by cutting the metal mask in the longitudinal direction beyond the through hole and acquiring cross-sectional profile data and then processing the data to calculate the taper angle (θ).

[0045] (Measurement of thin film linewidth after deposition)

[0046] Assuming the repeated use of the metal mask, for each metal mask sample of samples 1 to 8, six deposition samples were prepared, including those in which a deposition material with thicknesses of 0.5 μm, 1.0 μm, 5.0 μm, 10.0 μm, and 15.0 μm was intentionally deposited, respectively, and those in which no deposition material was deposited (deposition amount: 0.0 μm). The deposition thickness of the deposition material in the metal mask samples was controlled by using the metal mask samples under conditions equivalent to the thin film deposition process and repeating the process of depositing 0.5 μm.

[0047] A thin film with a thickness of 150 nm was deposited using each prepared metal mask sample, and the linewidth in the short-side direction of the thin film after deposition was measured. Nickel material was used for the thin film and the deposited material (target).

[0048] For measuring the linewidth, an image of the thin film was acquired by white interference scanning using a measuring instrument (VK-X3000 manufactured by Keyence). Using the acquired image of the thin film, a cross-sectional profile was obtained from the center of the short side using VK-X3000 multi-file analysis application software.

[0049] Figure 3A is an example of a thickness profile of a thin film (nickel film).

[0050] As shown in Fig. 3A, a straight line parallel to the bottom surface was set at a position of the maximum height of the membrane (H) - 10 nm (a position that is 10 nm lower in height than the maximum height of the membrane (H)), and the distance (W) between the intersection point of the said straight line and the membrane profile was defined as the line width.

[0051] The measured linewidth was expressed as a ratio based on the linewidth of a thin film deposited using a metal mask sample with a deposition amount of 0.0 μm.

[0052] (Evaluation Method)

[0053] Samples showing a change amount within 20% of the general “capacitance guarantee value of MLCC” were designated as “○” (OK), and samples showing a change amount exceeding 20% ​​were designated as “×” (NG).

[0054]

[0055] As shown in Table 1, in the metal mask samples of Sample 1 to Sample 6, in which the step height thickness dimension is 12.2 μm or less and the taper angle of the tapered portion located in the short direction is 47.0° or less, it was confirmed that good film deposition can be performed in any sample with a deposition thickness (metal mask deposition amount) of 0.0 μm to 15.0 μm, with the variation amount being within 20%.

[0056] Accordingly, by using a metal mask in which the thickness direction dimension of the step height is 12.2 μm or less and the taper angle of the tapered portion located in the short direction is 47.0° or less, a good film deposition can be achieved in which the amount of change is within 20% even if the deposition thickness of the film is 15.0 μm. Therefore, the deposition thickness of the film can be used as an indicator when cleaning the metal mask, and a method for managing the metal mask for forming internal electrodes of an MLCC can be established according to said indicator.

[0057] Specifically, a method for managing a metal mask for forming internal electrodes of an MLCC includes managing the upper limit of the dimensions in the thickness direction of the deposited film on the metal mask to 15 μm, and cleaning the metal mask when the dimensions in the thickness direction of the deposited film reach the upper limit.

[0058] Meanwhile, in the metal mask samples of Sample 7 to Sample 8, when the deposition thickness of the film was 15.0 μm, the taper angle exceeded 47.0° even though the thickness dimension of the step height was 12.2 μm or less, so the amount of change exceeded 20% and a good evaluation was not obtained.

[0059] That is, in this embodiment, samples 1 to 6 are examples, and samples 7 to 8 are comparative examples.

[0060] This is thought to be because, in addition to the reduced likelihood of flying out of the range of the penetration area (1b) when viewed from a plane at a point with a large taper angle and reaching the dielectric sheet (100), the film material is deposited in large quantities from the penetration area (1b) to the taper area, thereby shielding the film material flying out from the target (T) and inhibiting the formation of the thin film.

[0061] In addition, by making the thickness dimension of the step height 12.2 μm or less and the taper angle of the tapered portion located in the short direction 47.0° or less, it was possible to make (linewidth in the short direction of the thin film deposited in a metal mask sample with a deposition thickness of 1.0 μm) / (linewidth in the short direction of the thin film deposited in a metal mask sample with a deposition thickness of 0.0 μm) ≥ 0.97. That is, for samples 1 to 6 of Table 1 satisfying the above conditions, the value corresponding to a metal mask deposition amount of 1.0 μm is 0.97.

[0062] In addition, by making the thickness dimension of the step height 12.2 μm or less and the taper angle of the tapered portion located in the short side direction 47.0° or less, it was possible to make (linewidth in the short side direction of the thin film deposited in the metal mask sample with a deposition thickness of 5.0 μm) / (linewidth in the short side direction of the thin film deposited in the metal mask sample with a deposition thickness of 0.0 μm) ≥ 0.92. That is, for samples 1 to 6 of Table 1 satisfying the above conditions, the value corresponding to a metal mask deposition amount of 5.0 μm is 0.92 or more.

[0063] In addition, by making the thickness dimension of the step height 12.2 μm or less and the taper angle of the tapered portion located in the short direction 47.0° or less, it was possible to make (linewidth in the short direction of the thin film deposited in a metal mask sample with a deposition thickness of 10.0 μm) / (linewidth in the short direction of the thin film deposited in a metal mask sample with a deposition thickness of 0.0 μm) ≥ 0.90. That is, for samples 1 to 6 of Table 1 satisfying the above conditions, the value corresponding to a metal mask deposition amount of 10.0 μm is 0.90 or more.

[0064] In addition, by making the thickness dimension of the step height 12.2 μm or less and the taper angle of the tapered portion located in the short side direction 47.0° or less, it was possible to make (linewidth in the short side direction of the thin film deposited in the metal mask sample with a deposition thickness of 15.0 μm) / (linewidth in the short side direction of the thin film deposited in the metal mask sample with a deposition thickness of 0.0 μm) ≥ 0.80. That is, for samples 1 to 6 of Table 1 satisfying the above conditions, the value corresponding to the metal mask deposition amount of 15.0 μm is 0.80 or more.

[0065] Meanwhile, in the metal mask samples of Samples 1 to 4, in which the taper angle is 44.6° or less and the step height dimension in the thickness direction is 1.8 μm or more, it was confirmed that better film deposition could be achieved than in the metal mask samples of Samples 5 to 6, in samples with deposition thicknesses of 5.0 μm and 15.0 μm. That is, the values ​​corresponding to the metal mask deposition amounts of 5.0 μm and 15.0 μm for Samples 1 to 4 of Table 1 are greater than the values ​​corresponding to the metal mask deposition amounts of 5.0 μm and 15.0 μm for Samples 5 to 6 of Table 1. In short, the linewidth in the short-side direction of the thin film formed in metal mask samples with metal mask deposition amounts of 5.0 μm and 15.0 μm is closer to the linewidth in the short-side direction of the thin film formed in metal mask samples with a metal mask deposition amount of 0.0 μm in samples 1 to 4 compared to samples 5 to 6.

[0066] In addition, it was confirmed that in the metal mask samples of Sample 1 to Sample 2, where the taper angle is 40.3° or less and the step height dimension in the thickness direction is 10.0 μm or more, a better film deposition can be achieved than in the metal mask samples of Sample 3 to Sample 6, with deposition thicknesses of 5.0 μm, 10.0 μm, and 15.0 μm. That is, the values ​​corresponding to the metal mask deposition amounts of 5.0 μm, 10.0 μm, and 15.0 μm in Sample 1 to Sample 2 of Table 1 are greater than the values ​​corresponding to the metal mask deposition amounts of 5.0 μm, 10.0 μm, and 15.0 μm in Sample 3 to Sample 6 of Table 1. In short, the linewidth in the short-side direction of the thin film formed in metal mask samples with metal mask deposition amounts of 5.0 μm, 10.0 μm, and 15.0 μm is closer in samples 1 to 2 to the linewidth in the short-side direction of the thin film formed in a metal mask sample with a metal mask deposition amount of 0.0 μm compared to samples 3 to 6.

[0067] (Measurement of thin film thickness after membrane formation)

[0068] Apart from the linewidth of the thin film after deposition mentioned above, the film thickness of the thin film after deposition was measured.

[0069] Using the metal mask samples described above, assuming repeated use of the metal mask, for each metal mask sample of samples 1 to 5 and samples 7 to 8, six film samples were prepared, including those in which film thicknesses of 0.5 μm, 1.0 μm, 5.0 μm, 10.0 μm, and 15.0 μm were intentionally deposited, respectively, and those in which no film was deposited (deposited amount: 0.0 μm).

[0070] A thin film with a thickness of 150 nm was deposited using each prepared metal mask sample, and the film thickness of the thin film after deposition was measured. Nickel material was used for the thin film and the deposited material (target). The film thickness of the thin film after deposition was defined as the maximum deposition height (H) shown in Fig. 3.

[0071] The measured film thickness was expressed as a ratio based on the film thickness of the thin film formed using a metal mask sample with a deposition amount of 0.0 μm.

[0072] (Evaluation Method)

[0073] For a sample with a deposition amount of 15.0 μm, a sample showing a change in film thickness of 10% or less was designated as “○” (OK), and a sample showing a change exceeding 10% was designated as “×” (NG).

[0074]

[0075] As shown in Table 2, in the metal mask samples of Sample 3 to Sample 5, in which the step height dimension in the thickness direction is 8.3 μm or less and the taper angle of the tapered portion located in the short direction is 42.1° or more and 47.0° or less, it was confirmed that good film deposition can be performed in any sample with a deposition thickness of 0.0 μm to 15.0 μm, with a variation amount of within 10%.

[0076] Meanwhile, in the metal mask samples of Sample 1 to Sample 2, when the deposition thickness of the film was at least one of 1.0 μm, 5.0 μm, 10.0 μm, and 15.0 μm, the amount of change in film thickness exceeded 10%, so a good evaluation was not obtained.

[0077] This suggests that the shadow effect is strong due to the large dimension in the thickness direction of the step height, and that the film material may have reached the edge portions that do not contribute to the maximum film thickness of the thin film. Additionally, it is thought that the film material is deposited in large quantities from the penetration portion (1b) to the tapered portion, so that the film material flying from the target (T) is shielded by the film material, thereby hindering the formation of the thin film.

[0078] As such, when the amount of change in film thickness exceeds 10%, more than 1.1 times the film deposition process is required to form the same film thickness, and the time for repeating the stacking of thin films on one dielectric sheet (100) is also proportionally more than 1.1 times, which is undesirable as it reduces the stability of the total film thickness in addition to the decrease in production efficiency. Therefore, the problem described above can be resolved by making the thickness direction dimension of the step height 8.3 μm or less, and making the taper angle of the tapered portion located in the short side direction 42.1° or more and 47.0° or less.

[0079] Meanwhile, in the metal mask samples of Samples 3 to 4, where the step height dimension in the thickness direction is 3.1 μm or less and the taper angle of the tapered portion located in the short direction is 42.1° or more and 47.0° or less with respect to the short direction, it was confirmed that better film deposition could be achieved than in the metal mask sample of Sample 5 for samples with deposition thicknesses of 1.0 μm, 5.0 μm, and 10.0 μm. That is, the values ​​corresponding to the metal mask deposition amounts of 1.0 μm, 5.0 μm, and 10.0 μm for Samples 3 to 4 of Table 2 are greater than the values ​​corresponding to the metal mask deposition amounts of 1.0 μm, 5.0 μm, and 10.0 μm for Sample 5 of Table 2. In short, the linewidth in the short-side direction of the thin film formed in metal mask samples with metal mask deposition amounts of 1.0 μm, 5.0 μm, and 10.0 μm is closer to the linewidth in the short-side direction of the thin film formed in a metal mask sample with a metal mask deposition amount of 0.0 μm in samples 3 and 4 compared to sample 5.

[0080] In addition, it was confirmed that in the metal mask sample of Sample 4, in which the step height dimension in the thickness direction is 1.9 μm or less and the taper angle of the tapered portion located in the short direction relative to the short direction is 44.6° or more, better film deposition can be achieved than in the metal mask sample of Sample 5 for samples with deposition thicknesses of 5.0 μm, 10.0 μm, and 15.0 μm. That is, the values ​​corresponding to the metal mask deposition amounts of 5.0 μm, 10.0 μm, and 15.0 μm in Sample 4 of Table 2 are greater than the values ​​corresponding to the metal mask deposition amounts of 5.0 μm, 10.0 μm, and 15.0 μm in Sample 5 of Table 2. In short, the linewidth in the short-side direction of the thin film formed in metal mask samples with metal mask deposition amounts of 5.0 μm, 10.0 μm, and 15.0 μm is closer to the linewidth in the short-side direction of the thin film formed in a metal mask sample with a metal mask deposition amount of 0.0 μm in Sample 4 compared to Sample 5.

[0081] FIG. 4 shows an example of a member (50) that serves as an internal electrode for an MLCC, formed using a metal mask related to the present embodiment. The member (50) has a structure in which a thin film (20) made of a conductor is formed as an internal electrode on a substrate (dielectric sheet) (10) made of a dielectric material by a method of forming an internal electrode, which includes a method of forming an internal electrode pattern by sputtering, which is a type of physical vapor phase growth method using a metal mask related to the present embodiment.

[0082] The thin film (20) is formed using a metal mask related to the present embodiment, so that the line width in the short side direction is formed to be 80% or more of the line width when no film is deposited on the metal mask. The member (50) shown in FIG. 4 is divided into member (50A) and member (50B) in the longitudinal direction as indicated by the dotted line to become an internal electrode for an MLCC, and is used in multiple stacks so that the margin (11) without the thin film (20) is staggered as shown in FIG. 6. The member (50) shown in FIG. 5 is used in multiple stacks so that the margin (11) without the thin film (20) in FIG. 6 is staggered by cutting the end of either the left or right side in the longitudinal direction as indicated by the dotted line.

[0083] That is, the method of manufacturing an MLCC (a method of manufacturing a multilayer ceramic capacitor) comprises forming a thin film (20) that becomes an internal electrode on a substrate (10) shown in FIG. 4 by a method of forming an internal electrode including the method of forming an internal electrode pattern described above, dividing the substrate (10) shown in FIG. 4, on which the internal electrode is formed, into two parts in the longitudinal direction, a member (50A) and a member (50B), and stacking the divided substrate (10) in a plurality such that the margin (11) without the thin film (20) shown in FIG. 6 is staggered.

[0084] In addition, the method of forming an internal electrode, which includes the method of forming an internal electrode pattern described above, includes cutting the end of either the left or right side in the longitudinal direction at each of the two regions of the thin film (20) of the member (50) shown in FIG. 5, and stacking the cut substrate (10) in a plurality such that the margin (11) without the thin film (20) shown in FIG. 6 is staggered.

[0085] The member (50) shown in FIG. 4 can contribute to the desirable manufacture of an MLCC that guarantees the capacitance described above, because even after being divided into two parts, member (50A) and member (50B), the line width of the thin film is maintained within a predetermined range. The member (50) shown in FIG. 5 can contribute to the desirable manufacture of an MLCC that guarantees the capacitance described above, because even after being cut into member (50A) and member (50B) at each of the two parts of the thin film (20) region, the line width of the thin film is maintained within a predetermined range.

[0086] FIG. 6 is a diagram showing the positional relationship when the member (50) shown in FIG. 4 is divided into two equal parts, or when the end of either the left or right side in the longitudinal direction of each of the two regions of each thin film (20) shown in FIG. 5 is cut and then alternately stacked. In practice, this combination is considered as one set, and multiple sets are superimposed.

[0087] As shown in FIG. 6, the member (50) shown in FIG. 4, divided into two parts, member (50A) and member (50B), are stacked with both ends in the longitudinal direction symmetrically positioned. Also, in the case of the member (50) shown in FIG. 5, the member (50A) and member (50B), with one end of either the left or right side cut off from each of the two thin film (20) regions, are stacked with both ends in the longitudinal direction symmetrically positioned.

[0088] In the stacked member (50A) and member (50B), the area indicated by the dashed line in FIG. 6, where the thin film (20A) in member (50A) and the thin film (20B) in member (50B) overlap, functions as a substantial capacitor. Additionally, in a stacked state where the thin film (20A) in member (50A) exposed at the longitudinal end (right end) and the thin film (20B) in member (50B) exposed at the longitudinal end (left end) are stacked, an external terminal is connected to each.

[0089] As described above, in the metal mask (1) of the present embodiment, the dimension of the penetration portion (1b) in the short side direction is 300 μm or less, the dimension of the step height (h1) located in the short side direction in the thickness direction is 12.2 μm or less, and the taper angle of the tapered portion (h2) located in the short side direction is 47.0° or less with respect to the short side direction, so the shape of the internal electrode is good and it is possible to form an internal electrode with good electrical characteristics.

[0090] In addition, in the metal mask (1) of the present embodiment, the reduction in the effective area when used repeatedly is small. In the method of managing the metal mask for forming internal electrodes of an MLCC, the number of times the metal mask (1) is cleaned can be reduced by managing the upper limit of the dimension in the thickness direction of the deposited film on the metal mask (1) to 15 μm, and as a result, it is possible to extend the period until the metal mask (1) is discarded.

[0091] Although preferred embodiments related to the present invention have been described above with reference to the attached drawings, the present invention is not limited to these examples. The various shapes or combinations of each constituent member shown in the examples described above are merely examples, and can be varied based on design requirements, etc., without departing from the well-known principles of the present invention.

[0092] For example, the substrate of the metal mask related to the present invention is not limited to stainless steel such as SUS430 used in the above-described review. For example, other magnetic metal substrates made of alloys such as Invar or Super Invar may be used. If the thin film metal substrate is formed from a magnetic metal material as described above, there is an advantage that it can be fixed to a film deposition device using magnetic force. In addition, the thickness of the substrate is not limited to 50 μm in the above-described review, and even if the thickness is different, the same effect is achieved by using a step height or taper angle within the above-described range.

[0093] In addition, regarding the metal mask related to the present invention, when typically mounted on a film deposition device, it is possible to face either side in the thickness direction toward the substrate, and the step height changes accordingly; however, the step height in the present invention is defined as the lower value among the above. Furthermore, regarding the step height in the metal mask related to the present invention, considering the manufacturing process, the cross-section in the short side direction of the through hole is different from the cross-section in the long side direction; therefore, for the sake of clarity in definition, the step height in the cross-section extending in the long side direction of the part forming the edge of the short side of the through hole, that is, the step height in the short side direction, is used.

[0094] Next, the measurement results using samples 1A to 7A are described.

[0095] (Measurement of thin film thickness after membrane formation)

[0096] Assuming the repeated use of the metal mask, for each metal mask sample of Samples 1A to 7A, six deposition samples were prepared, including those in which a deposition material with thicknesses of 0.5 μm, 1.0 μm, 5.0 μm, 10.0 μm, and 15.0 μm was intentionally deposited, respectively, and those in which no deposition material was deposited (deposition amount: 0.0 μm). The deposition thickness of the deposition material in the metal mask samples was controlled by using the metal mask samples under conditions equivalent to the thin film deposition process and repeating the process of depositing 0.5 μm.

[0097] A thin film with a thickness of 150 nm was deposited using each prepared metal mask sample, and the film thickness was measured after deposition. Nickel material was used for the thin film and the deposited material (target). To measure the film thickness, an image of the thin film was acquired by white interference scanning using a measuring instrument (VK-X3000 manufactured by Keyence). A cross-sectional profile was acquired from the center of the short side of the acquired thin film image using VK-X3000 multi-file analysis application software.

[0098] Figure 3B is an example of a thickness profile of a nickel film. As shown in Figure 3B, the film thickness of the thin film was defined as the maximum film height (H) from a straight line parallel to the bottom surface. The measured film thickness was expressed as a ratio based on the film thickness of a thin film deposited using a metal mask sample with a deposition amount of 0.0 μm.

[0099] (Evaluation Method)

[0100] For a sample with a deposition amount of 15.0 μm, a sample showing a change in film thickness of 10% or less was designated as “○” (OK), and a sample showing a change exceeding 10% was designated as “×” (NG).

[0101]

[0102] As shown in Table 3, in the metal mask samples of Sample 1A to Sample 5A, in which the step height dimension in the thickness direction is 8.3 μm or less and the taper angle of the tapered portion located in the short direction is 50.2° or less, it was confirmed that good film deposition can be performed with a variation amount of within 10% in any sample with a deposition thickness of 0.0 μm to 15.0 μm.

[0103] Accordingly, by using a metal mask in which the thickness direction dimension of the step height is 8.3 μm or less and the taper angle of the tapered portion located in the short direction is 50.2° or less, a good film deposition can be achieved in which the amount of change is within 10% even if the deposition thickness of the film is 15.0 μm. Therefore, the deposition thickness of the film can be used as an indicator when cleaning the metal mask, and a method for managing the metal mask for forming internal electrodes of an MLCC can be established according to said indicator.

[0104] Specifically, a method for managing a metal mask for forming internal electrodes of an MLCC includes managing the upper limit of the dimensions in the thickness direction of the deposited film on the metal mask to 15 μm, and cleaning the metal mask when the dimensions in the thickness direction of the deposited film reach the upper limit.

[0105] Meanwhile, in the metal mask samples of samples 6A to 7A, at least one of the deposition thickness of the film material was 1.0 μm, 5.0 μm, 10.0 μm, and 15.0 μm, the amount of change in film thickness exceeded 10%, so a good evaluation was not obtained.

[0106] That is, in this embodiment, samples 1A to 5A are examples, and samples 6A to 7A are comparative examples.

[0107] This suggests that the shadow effect is strong due to the large thickness dimension of the step height, and that the film material may have reached the edge portions that do not contribute to the maximum film thickness of the thin film. Additionally, it is thought that the film material is deposited in large quantities from the penetration portion (1b) to the tapered portion, so that the film material flying from the target (T) is shielded by the film material, thereby hindering the formation of the thin film.

[0108] As such, when the amount of change in film thickness exceeds 10%, more than 1.1 times the film deposition process is required to form the same film thickness, and the time for repeating the stacking of thin films on one dielectric sheet (100) is also proportionally more than 1.1 times, which is undesirable as it reduces the stability of the total film thickness in addition to the decrease in production efficiency. Therefore, the problem described above can be resolved by making the thickness direction dimension of the step height 8.3 μm or less and the taper angle of the tapered portion located in the short direction 50.2° or less relative to the short direction.

[0109] In addition, by making the thickness dimension of the step height 8.3 μm or less and the taper angle of the tapered portion located in the short side direction 50.2° or less, it was possible to make (thickness of the central part of the thin film formed in the metal mask sample with a deposition thickness of 1.0 μm) / (thickness of the central part of the thin film formed in the metal mask sample with a deposition thickness of 0.0 μm) ≥ 0.94. That is, for samples 1A to 5A of Table 3 satisfying the above conditions, the value corresponding to a metal mask deposition amount of 1.0 μm is 0.94 or greater.

[0110] In addition, by making the thickness dimension of the step height 8.3 μm or less and the taper angle of the tapered portion located in the short side direction 50.2° or less relative to the short side direction, it was possible to make (thickness of the central part of the thin film formed in the metal mask sample with a deposition thickness of 5.0 μm) / (thickness of the central part of the thin film formed in the metal mask sample with a deposition thickness of 0.0 μm) ≥ 0.93. That is, for samples 1A to 5A of Table 3 satisfying the above conditions, the value corresponding to a metal mask deposition amount of 5.0 μm is 0.93 or more.

[0111] In addition, by making the thickness dimension of the step height 8.3 μm or less and the taper angle of the tapered portion located in the short side direction 50.2° or less with respect to the short side direction, it was possible to make (thickness of the central part of the thin film formed in the metal mask sample with a deposition thickness of 10.0 μm) / (thickness of the central part of the thin film formed in the metal mask sample with a deposition thickness of 0.0 μm) ≥ 0.91. That is, for samples 1A to 5A of Table 3 satisfying the above conditions, the value corresponding to a metal mask deposition amount of 10.0 μm is 0.91 or more.

[0112] In addition, by making the thickness dimension of the step height 8.3 μm or less and the taper angle of the tapered portion located in the short side direction 50.2° or less with respect to the short side direction, it was possible to make (thickness of the central part of the thin film formed in the metal mask sample with a deposition thickness of 15.0 μm) / (thickness of the central part of the thin film formed in the metal mask sample with a deposition thickness of 0.0 μm) ≥ 0.90. That is, the value corresponding to the metal mask deposition amount of 15.0 μm for samples 1A to 5A of Table 3 satisfying the above conditions is 0.90 or more.

[0113] Meanwhile, in the metal mask samples of Samples 1A to 4A, in which the step height dimension in the thickness direction is 5.7 μm or less and the taper angle of the tapered portion located in the short direction relative to the short direction is 50.2° or less, it was confirmed that better film deposition could be achieved than in the metal mask sample of Sample 5A for a sample with a deposition thickness of 1.0 μm. That is, the value corresponding to the metal mask deposition amount of 1.0 μm for Samples 1A to 4A of Table 3 is greater than the value corresponding to the metal mask deposition amount of 1.0 μm for Sample 5A of Table 3. In short, the linewidth in the short direction of the thin film formed in the metal mask sample with a metal mask deposition amount of 1.0 μm is closer to the linewidth in the short direction of the thin film formed in the metal mask sample with a metal mask deposition amount of 0.0 μm in samples 1A to 4A compared to sample 5A.

[0114] In addition, it was confirmed that in the metal mask samples of Samples 1A to 3A, in which the step height dimension in the thickness direction is 3.1 μm or less and the taper angle of the tapered portion located in the short direction relative to the short direction is 42.1° or more, better film deposition can be achieved than in the metal mask samples of Samples 4A to 5A for samples with deposition thicknesses of 1.0 μm and 5.0 μm. That is, the values ​​corresponding to the metal mask deposition amounts of 1.0 μm and 5.0 μm for Samples 1A to 3A in Table 3 are greater than the values ​​corresponding to the metal mask deposition amounts of 1.0 μm and 5.0 μm for Samples 4A to 5A in Table 3. In short, the linewidth in the short direction of the thin film formed in metal mask samples with metal mask deposition amounts of 1.0 μm and 5.0 μm is closer to the linewidth in the short direction of the thin film formed in metal mask samples with a metal mask deposition amount of 0.0 μm in samples 1A to 3A compared to samples 4A to 5A.

[0115] In addition, it was confirmed that in the metal mask samples of Sample 1A to Sample 2A, in which the step height dimension in the thickness direction is 1.9 μm or less and the taper angle of the tapered portion located in the short direction relative to the short direction is 44.6° or more, better film deposition can be achieved than in the metal mask sample of Sample 5A for samples with deposition thicknesses of 5.0 μm, 10.0 μm, and 15.0 μm. That is, the values ​​corresponding to the metal mask deposition amounts of 5.0 μm, 10.0 μm, and 15.0 μm for Samples 1A to 2A in Table 3 are greater than the values ​​corresponding to the metal mask deposition amounts of 5.0 μm, 10.0 μm, and 15.0 μm for Sample 5A in Table 3. In short, the linewidth in the short-side direction of the thin film formed in metal mask samples with metal mask deposition amounts of 5.0 μm, 10.0 μm, and 15.0 μm is closer to the linewidth in the short-side direction of the thin film formed in a metal mask sample with a metal mask deposition amount of 0.0 μm in samples 1A to 2A compared to sample 5A.

[0116] In addition, it was confirmed that in the metal mask sample of Sample 1A, in which the step height dimension in the thickness direction is 0.8 μm or less and the taper angle of the tapered portion located in the short direction relative to the short direction is 48.4° or more, better film deposition can be achieved than in the metal mask samples of Samples 2A to 5A for samples with deposition thicknesses of 5.0 μm, 10.0 μm, and 15.0 μm. That is, the values ​​corresponding to the metal mask deposition amounts of 5.0 μm, 10.0 μm, and 15.0 μm in Sample 1A of Table 3 are greater than the values ​​corresponding to the metal mask deposition amounts of 5.0 μm, 10.0 μm, and 15.0 μm in Samples 2A to 5A of Table 3. In short, the linewidth in the short-side direction of the thin film formed in metal mask samples with metal mask deposition amounts of 5.0 μm, 10.0 μm, and 15.0 μm is closer to the linewidth in the short-side direction of the thin film formed in a metal mask sample with a metal mask deposition amount of 0.0 μm in Sample 1A compared to Samples 2A to 5A.

[0117] FIG. 4 shows an example of a member (50) that serves as an internal electrode for an MLCC, formed using a metal mask related to the present embodiment. The member (50) has a structure in which a thin film (20) made of a conductor is formed as an internal electrode on a substrate (dielectric sheet) (10) made of a dielectric material by a method of forming an internal electrode, which includes a method of forming an internal electrode pattern by sputtering, which is a type of physical vapor phase growth method using a metal mask related to the present embodiment.

[0118] The thin film (20) is formed using a metal mask related to the present embodiment, so that the film thickness in the central part is formed to be 90% or more of the film thickness when no film material is deposited on the metal mask. The member (50) shown in FIG. 4 is divided into member (50A) and member (50B) in the longitudinal direction as indicated by the dotted line to become an internal electrode for an MLCC, and is used in multiple stacks so that the margin (11) without the thin film (20) is staggered as shown in FIG. 6. The member (50) shown in FIG. 5 is used in multiple stacks so that the margin (11) without the thin film (20) in FIG. 6 is staggered by cutting the end of either the left or right side in the longitudinal direction as indicated by the dotted line.

[0119] That is, the method of manufacturing an MLCC (a method of manufacturing a multilayer ceramic capacitor) comprises forming a thin film (20) that becomes an internal electrode on a substrate (10) shown in FIG. 4 by a method of forming an internal electrode including the method of forming an internal electrode pattern described above, dividing the substrate (10) shown in FIG. 4, on which the internal electrode is formed, into two parts in the longitudinal direction, a member (50A) and a member (50B), and stacking the divided substrate (10) in a plurality such that the margin (11) without the thin film (20) shown in FIG. 6 is staggered.

[0120] Additionally, the method for manufacturing an MLCC (a method for manufacturing a multilayer ceramic capacitor) includes cutting one end of either the left or right side in the longitudinal direction at each of the two thin film (20) regions of the member (50) shown in FIG. 5 by the method for forming an internal electrode including the method for forming an internal electrode pattern described above, and stacking the cut substrates (10) in a plurality such that the margins (11) without the thin film (20) shown in FIG. 6 are staggered.

[0121] The member (50) shown in FIG. 4 can contribute to the desirable manufacture of an MLCC that guarantees the capacitance described above, because even after being divided into two parts, member (50A) and member (50B), the film thickness of the thin film is maintained within a predetermined range. The member (50) shown in FIG. 5 can contribute to the desirable manufacture of an MLCC that guarantees the capacitance described above, because even after being cut into member (50A) and member (50B) in each of the two parts of the thin film (20) region, the film thickness of the thin film is maintained within a predetermined range.

[0122] FIG. 6 is a diagram showing the positional relationship when the member (50) shown in FIG. 4 is divided into two equal parts, or when the end of either the left or right side in the longitudinal direction of each of the two regions of each thin film (20) shown in FIG. 5 is cut and then alternately stacked. In practice, this combination is considered as one set, and multiple sets are superimposed.

[0123] As shown in FIG. 6, the member (50) shown in FIG. 4, divided into two parts, member (50A) and member (50B), are stacked with both ends in the longitudinal direction symmetrically positioned. Also, in the case of the member (50) shown in FIG. 5, the member (50A) and member (50B), with one end of either the left or right side cut off from each of the two thin film (20) regions, are stacked with both ends in the longitudinal direction symmetrically positioned.

[0124] In the stacked member (50A) and member (50B), the area indicated by the dashed line in FIG. 6, where the thin film (20A) in member (50A) and the thin film (20B) in member (50B) overlap, functions as a substantial capacitor. Additionally, in a stacked state where the thin film (20A) in member (50A) exposed at the longitudinal end (right end) and the thin film (20B) in member (50B) exposed at the longitudinal end (left end) are stacked, an external terminal is connected to each.

[0125] As described above, in the metal mask (1) of the present embodiment, the dimensions of the penetration portion (1b) in the short side direction are 300 μm or less, the dimensions of the step height (h1) in the thickness direction located in the short side direction are 8.3 μm or less, and the taper angle of the tapered portion (h2) located in the short side direction is 50.2° or less with respect to the short side direction, so it is possible to form an internal electrode with good electrical characteristics and a good film formation rate.

[0126] In addition, in the metal mask (1) of the present embodiment, the reduction in the effective area when used repeatedly is small. In the method of managing the metal mask for forming internal electrodes of an MLCC, the number of times the metal mask (1) is cleaned can be reduced by managing the upper limit of the dimension in the thickness direction of the deposited film on the metal mask (1) to 15 μm, and as a result, it is possible to extend the period until the metal mask (1) is discarded.

[0127] Although preferred embodiments related to the present invention have been described above with reference to the attached drawings, the present invention is not limited to these examples. The various shapes or combinations of each constituent member shown in the examples described above are merely examples, and can be varied based on design requirements, etc., without departing from the well-known principles of the present invention.

[0128] For example, the substrate of the metal mask related to the present invention is not limited to stainless steel such as SUS430 used in the above-described review. For example, other magnetic metal substrates made of alloys such as Invar or Super Invar may be used. If the thin film metal substrate is formed from a magnetic metal material as described above, there is an advantage that it can be fixed to a film deposition device using magnetic force. In addition, the thickness of the substrate is not limited to 50 μm in the above-described review, and even if the thickness is different, the same effect is achieved by using a step height or taper angle within the above-described range.

[0129] In addition, regarding the metal mask related to the present invention, when typically mounted on a film deposition device, it is possible to face either side in the thickness direction toward the substrate, and the step height changes accordingly; however, the step height in the present invention is defined as the lower value among the above. Furthermore, regarding the step height in the metal mask related to the present invention, considering the manufacturing process, the cross-section in the short side direction of the through hole is different from the cross-section in the long side direction; therefore, for the sake of clarity in definition, the step height in the cross-section extending in the long side direction of the part forming the edge of the short side of the through hole, that is, the step height in the short side direction, is used. Explanation of the symbols

[0130] 1 : Metal mask 1a : Penetrating hole 1b : Penetrating area 10 : Substrate 20 : Thin film (internal electrode) 21 : Top surface 22 : Bottom surface 100 : Dielectric sheet (substrate) 110 : Entry h1 : Step height h2 : Tapered section

Claims

Claim 1 A metal mask for manufacturing an internal electrode of a multilayer ceramic capacitor, wherein a rectangular through hole is formed in a metal substrate when viewed from a planar view, wherein the dimension of the through portion in the direction of the rectangular short side when viewed from a planar view is 300 μm or less, and in the cross-sectional shape of the perimeter edge facing the through portion, a step height is formed on the first side in the thickness direction of the substrate, and a tapered portion is formed on the second side in the thickness direction extending away from the through portion, wherein the dimension of the step height in the thickness direction located in the short side direction is 12.2 μm or less, and the tapered portion located in the short side direction has a taper angle with respect to the short side direction of 47.0° or less, and is a sputtering mask used to perform sputtering in a desired pattern. Claim 2 A metal mask according to claim 1, wherein the taper angle is 44.6° or less, and the dimension of the step height in the thickness direction is 1.8 μm or more. Claim 3 A metal mask according to claim 2, wherein the taper angle is 40.3° or less, and the dimension of the step height in the thickness direction is 10.0 μm or more. Claim 4 A metal mask according to claim 1, wherein the dimension in the thickness direction of the step height is 8.3 μm or less, and the taper angle is 42.1° or more and 47.0° or less. Claim 5 In claim 4, a metal mask in which the dimension in the thickness direction of the step height is 3.1 μm or less. Claim 6 A metal mask according to claim 5, wherein the dimension in the thickness direction of the step height is 1.9 μm or less, and the taper angle is 44.6° or more. Claim 7 A method for forming an internal electrode pattern of a multilayer ceramic capacitor, comprising forming the internal electrode by a physical vapor phase growth method using a metal mask described in any one of claims 1 to 6. Claim 8 A method for forming an internal electrode of a multilayer ceramic capacitor, comprising forming the internal electrode using the method for forming an internal electrode pattern of a multilayer ceramic capacitor described in claim 7. Claim 9 A method for manufacturing a multilayer ceramic capacitor, comprising forming the internal electrode using the method for forming the internal electrode of the multilayer ceramic capacitor described in claim 8. Claim 10 A method for managing a metal mask for forming an internal electrode of a multilayer ceramic capacitor, comprising managing the upper limit of the thickness direction dimension of a deposited film on a metal mask described in any one of claims 1 to 6 to be 15 μm, and cleaning the metal mask when the thickness direction dimension of the deposited film reaches the upper limit. Claim 11 A metal mask for manufacturing an internal electrode of a multilayer ceramic capacitor, wherein a rectangular through hole is formed in a metal substrate when viewed from a planar view, wherein the dimension of the through hole in the direction of the rectangular short side when viewed from a planar view is 300 μm or less, and in the cross-sectional shape of the perimeter edge facing the through hole, a step height is formed on one side in the thickness direction of the substrate, and a tapered portion is formed on the other side in the thickness direction extending away from the through hole, wherein the dimension of the step height in the thickness direction located in the short side direction is 8.3 μm or less, and the tapered portion located in the short side direction has a taper angle with respect to the short side direction of 50.2° or less, and is a sputtering mask used to perform sputtering in a desired pattern. Claim 12 A metal mask according to claim 11, wherein the dimension in the thickness direction of the step height is 5.7 μm or less. Claim 13 A metal mask according to claim 12, wherein the dimension in the thickness direction of the step height is 3.1 μm or less, and the taper angle is 42.1° or more. Claim 14 A metal mask according to claim 13, wherein the dimension in the thickness direction of the step height is 1.9 μm or less, and the taper angle is 44.6° or more. Claim 15 A metal mask according to claim 14, wherein the dimension in the thickness direction of the step height is 0.8 μm or less, and the taper angle is 48.4° or more. Claim 16 A method for forming an internal electrode pattern of a multilayer ceramic capacitor, comprising forming the internal electrode by a physical vapor phase growth method using a metal mask described in any one of claims 11 to 15. Claim 17 A method for forming an internal electrode of a multilayer ceramic capacitor, comprising forming the internal electrode using the method for forming an internal electrode pattern of a multilayer ceramic capacitor described in claim 16. Claim 18 A method for manufacturing a multilayer ceramic capacitor, comprising forming the internal electrode using the method for forming the internal electrode of the multilayer ceramic capacitor described in claim 17. Claim 19 A method for managing a metal mask for forming an internal electrode of a multilayer ceramic capacitor, comprising managing the upper limit of the thickness direction dimension of a deposited film on a metal mask described in any one of claims 11 to 15 to be 15 μm, and cleaning the metal mask when the thickness direction dimension of the deposited film reaches the upper limit.

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