JP7493837B2 - Metal mask for printing - Google Patents

Description

The present invention relates to a printing metal mask for printing internal electrodes of a capacitor.

Conventionally, multilayer ceramic capacitors are manufactured by printing conductive paste to be internal electrodes on ceramic green sheets using a screen printing plate, stacking and firing a plurality of these ceramic green sheets, and then cutting the stack into individual pieces. A plurality of internal electrodes are printed on the ceramic green sheets at once, and a large number of printing holes of the same shape are formed on the screen printing plate (see, for example, Patent Document 1). In addition, when screen printing is performed, a phenomenon occurs in which both ends of the printed pattern are raised and saddle-shaped, so that when the ceramic green sheets on which the printed pattern is formed are stacked and pressed, the withstand voltage failure rate increases. In order to improve this, a printed pattern forming material is known that does not form a large rise at both ends of the printed pattern and forms a nearly flat printed pattern (see Patent Document 2). Also known is a mask having a mesh for printing pattern openings in which diamond-shaped holes are regularly formed in the center of a specified rectangular area, and pentagonal holes including some of the sides of the diamonds and some of the sides that form the rectangular area are regularly formed at the ends (periphery) of the rectangular area, and in which home plate-shaped pentagonal holes are formed at the ends excluding the corners (four corners) of the rectangular area, and diamond-shaped pentagonal holes are formed at the corners of the rectangular area (see Patent Document 3).

JP 2001-39048 A JP 2005-212285 A Patent No. 5395850

In the conventional printing pattern forming materials or masks described in Patent Document 2 or Patent Document 3, as the masks have become thinner and the mesh holes of the printing pattern have become finer in order to print thinner, the phenomenon in which both ends of the printing pattern rise up and form a saddle shape (the conductive paste becomes thicker at the outer periphery than at the inside) has become more noticeable and this phenomenon is becoming more pronounced, so it has become essential to further reduce the saddle phenomenon in the printing pattern that accompanies the thinner masks and finer mesh holes of the printing pattern.

The present invention has been made to solve the problems described above, and provides a printing metal mask in which the area of mesh holes arranged on the periphery of the printing pattern is smaller than the area of mesh holes arranged in the center, thereby making it possible to reduce the saddle phenomenon in the printing pattern that occurs with thinner masks and finer mesh holes in the printing pattern.

The printing metal mask according to the present invention is used for printing a paste and comprises a flat mask body having two parallel upper and lower surfaces, a recess formed on the lower surface of the mask body facing the printed material and recessed toward the upper surface of the mask body, and a large number of diamond-shaped mesh holes formed in a printing pattern area formed on the upper surface of the mask body . The large number of mesh holes include large diamond-shaped mesh holes arranged in large numbers in the center of the printing pattern area, small diamond-shaped mesh holes arranged on the outer periphery of the large diamond-shaped mesh holes and having a mesh hole area smaller than that of the large diamond-shaped mesh holes in the center, home plate-shaped pentagonal mesh holes arranged on the outermost periphery excluding the corners of the printing pattern area and having the same area as the small diamond-shaped mesh holes in the outer periphery, and diamond-shaped pentagonal mesh holes arranged on the corners of the printing pattern area and having a mesh hole area smaller than that of the large diamond-shaped mesh holes in the center .

According to this invention, the area of the mesh holes arranged on the outer periphery of the printing pattern is made smaller than the area of the mesh holes arranged in the center of the printing pattern, thereby significantly reducing the saddle phenomenon of the printing pattern that occurs when the mask is made thinner and the mesh holes of the printing pattern are made finer.

FIG. 2 is a bottom view of a portion of the printing metal mask according to the first embodiment of the present invention, as viewed from below. 2 is a cross-sectional view of the printing metal mask shown in FIG. 1 taken along line AA, with a central portion omitted. 2 is a cross-sectional view of the printing metal mask taken along line BB of FIG. 1, with a portion of the central portion omitted. 1 is a plan view of a portion of a printing metal mask according to a first embodiment of the present invention, as viewed from above. FIG. 1 is a cross-sectional view showing a printed pattern when printing is performed using a printing metal mask in Example 1 of the present invention. FIG. FIG. 11 is a cross-sectional view showing a printed pattern when printing is performed using a conventional metal mask for printing as a comparative example. FIG. 11 is a bottom view of a portion of a printing metal mask according to a second embodiment of the present invention, as viewed from below.

Example 1.
FIG. 1 is a bottom view of a portion of a printing metal mask in Example 1 of the present invention, as viewed from below, FIG. 2 is a cross-sectional view along line A-A in FIG. 1, FIG. 3 is a cross-sectional view along line B-B in FIG. 1, FIG. 4 is a plan view of the same portion of the printing metal mask, as viewed from above, FIG. 5 is a cross-sectional view showing a printed pattern when printing is performed using a printing metal mask, and FIG. 6 is a cross-sectional view showing a printed pattern when printing is performed using a conventional printing metal mask as a comparative example.
The printing metal mask 1 comprises a flat mask body 2 having two parallel upper and lower surfaces, a horizontally elongated rectangular recess 3 formed on the lower surface of the mask body 2 facing the printing substrate, and a large number of mesh holes 5 having a basic shape of a rhombus formed in a horizontally elongated rectangular printing pattern region 4 on the upper surface of the mask body 2. The mask body 2 is thinned to a total thickness of about 10 to 25 μm, and the horizontally elongated rectangular recess 3 is recessed toward the upper surface with a depth of about 1 to 5 μm. The outer peripheral side wall of the horizontally elongated rectangular recess 3 is formed so as to surround the periphery of the horizontally elongated rectangular printing pattern region 4, and the region in which the horizontally elongated rectangular printing pattern region 4 is formed is formed inside the outer peripheral side wall of the horizontally elongated rectangular recess 3. In the illustration of the printing metal mask 1, only the mask body 2, the horizontally long rectangular recesses 3, and a portion of the horizontally long rectangular printing pattern region 4 are shown, but in reality, the mask body 2, the horizontally long rectangular recesses 3, and the horizontally long rectangular printing pattern region 4 are continuously arranged vertically and horizontally. Of the numerous mesh holes 5 having a diamond shape as a basic shape formed in the horizontally long rectangular printing pattern region 4, the large diamond-shaped mesh holes 5a, most of which are arranged in the center of the printing pattern region 4, are arranged in a total of 143 holes, 3 to 4 holes vertically and 20 to 21 holes horizontally, in this embodiment, and have a mesh hole opening of about 19 to 25 μm and a mesh wire diameter D1 of about 16 to 10 μm, with the mesh hole area being S1. Among the numerous mesh holes 5 having a diamond shape as a basic shape formed in the horizontally elongated rectangular print pattern region 4, the smaller diamond-shaped mesh holes 5b, which are smaller than the large diamond-shaped mesh holes 5a and arranged in a vertical row adjacent to the left and right end portions of the large diamond-shaped mesh holes 5a, are arranged in a vertical direction, four on each side, for a total of eight, in this embodiment. For example, the mesh hole opening is about 18 to 23 μm, the mesh wire diameter D2 is about 17 to 12 μm, and if the mesh hole area is S2, the correlation of the mesh areas is S1>S2. Also, the correlation of the mesh wire diameters is D1<D. The small diamond-shaped mesh holes 5b may be arranged in two or three vertical rows adjacent to at least one of the left and right end portions. Among the numerous mesh holes 5 formed in the horizontally elongated rectangular print pattern region 4 and having a diamond shape as a basic shape, the home plate-shaped pentagonal mesh holes 5c arranged at both the left and right ends and the top and bottom ends of the horizontally elongated rectangular print pattern region 4 excluding each corner are arranged in this embodiment with 6 holes arranged vertically and 42 holes arranged horizontally, for a total of 48 holes, and for example, the mesh hole opening is about 18 to 23 μm, the mesh wire diameter D3 is about 17 to 12 μm, and if the mesh hole area is S3, the correlation of the mesh areas is S1>S2≒S3, and the mesh holes are small. Also, the correlation of the mesh wire diameters is D1<D2≒D3. In addition, among the many mesh holes 5 formed in the horizontally elongated rectangular print pattern region 4 and having a rhombus as a basic shape, the diamond-shaped pentagonal mesh holes 5d arranged at each corner of the horizontally elongated rectangular print pattern region 4 are arranged in this embodiment, one at each of the four corners, for a total of four, and for example, the mesh hole opening is about 17 to 21 μm and the mesh wire diameter D4 is about 18 to 14 μm, but for example, the mesh hole opening, which is the same size as the home base-shaped pentagonal mesh hole 5c, may be about 18 to 23 μm and the mesh wire diameter D4 may be about 17 to 12 μm. If the mesh hole area is S4, the correlation of the mesh areas is S1>S2≒S3>S4, or S1>D2≒S3≒S4, and the mesh hole is smaller than the home base-shaped pentagonal mesh hole 5c, or is the same size as the home base-shaped pentagonal mesh hole 5c. The mesh wire diameters have a correlation of D1<D2≒D3<D4, or D1<D2≒D3≒D4. The diamond-shaped pentagonal mesh holes 5d do not have to be disposed at all corners (four corners) of the horizontally elongated rectangular printing pattern area 4, and may be disposed at, for example, two locations (two corners) that are diagonally opposite to each other.
Among the many mesh holes 5 having a diamond shape as a basic shape formed in the horizontally elongated rectangular printing pattern region 4, the area S2 of the small diamond-shaped mesh holes 5b arranged in the first to fourth rows on the outer periphery of the horizontally elongated rectangular printing pattern region 4, the area S3 of the home base-shaped pentagonal mesh hole 5c, and the area S4 of the diamond-shaped pentagonal mesh hole 5d are made smaller by about 5 to 30% than the area S1 of the large mesh hole 5a arranged in the center, as shown in Figure 5, by making it possible to avoid the phenomenon in which both ends of the printing pattern (conductive paste, etc.) rise and become saddle-like due to the thinning of the mask and the fineness of the mesh holes of the printing pattern, and it is possible to significantly reduce the saddle phenomenon, and a remarkable effect can be expected with a mask having a plate thickness of about 10 to 25 μm. Note that, when printing is performed using a conventional printing metal mask as a comparative example, the phenomenon in which both ends of the printing pattern rise and become saddle-like is unavoidable, as shown in Figure 6.

Example 2.
FIG. 7 is a bottom view of a portion of a printing metal mask according to a second embodiment of the present invention, as viewed from below.
In the above embodiment 1, an example was shown in which diamond-shaped mesh holes 5b smaller than the large diamond-shaped mesh holes 5a, which have a diamond shape as their basic shape, are arranged in a vertical row adjacent to the left and right end portions of the large diamond-shaped mesh hole 5a arranged in the center, but in this embodiment 2, diamond-shaped mesh holes 5b smaller than the large diamond-shaped mesh holes 5a, which have a diamond shape as their basic shape, are added not only to the left and right end portions of the large mesh hole 5a arranged in the center, but also to the upper and lower end portions and arranged in a horizontal row. Note that these small diamond-shaped mesh holes 5b may be arranged in two or three vertical rows adjacent to at least one of the left and right end portions and at least one of the upper and lower end portions. The correlation between the mesh areas is S1>S2≒S3>S4, or S1>D2≒S3≒S4, as in Example 1, and the correlation between the mesh wire diameters is D1<D2≒D3<D4, or D1<D2≒D3≒D4, as in Example 1.

Example 3.
In the above-mentioned Examples 1 and 2, the printing metal mask having a large number of mesh holes 5 with a basic shape of a rhombus formed in the horizontally elongated rectangular printing pattern region 4 on the upper surface side of the mask main body 2 has been described, but the shape of the large number of mesh holes 5 is not limited to a rhombus, a home plate shape, or a diamond shape, and may be, for example, a triangle, a square, other polygons, a circle, etc. In short, by making the areas S2 to S4 of the small or smallish mesh holes 5b to 5d arranged in the first to fourth rows on the outer periphery of the horizontally elongated rectangular printing pattern region 4 smaller by about 5 to 30% than the area S1 of the large mesh hole 5a arranged in the center, it is possible to avoid the phenomenon in which both ends of the printing pattern (conductive paste, etc.) rise up and become saddle-like due to the thinning of the mask and the fineness of the mesh holes of the printing pattern, and some modification is acceptable as long as it is possible to significantly reduce the saddle phenomenon.

1 Metal mask for printing 2 Mask body 3 Horizontally elongated rectangular recess 4 Horizontally elongated rectangular print pattern area 5 Numerous mesh holes 5a Large diamond-shaped mesh hole 5b arranged in the center Smaller diamond-shaped mesh holes 5c arranged on both left and right ends or both top and bottom ends Pentagonal mesh hole 5d in the shape of a home base Pentagonal mesh hole in the shape of a diamond

Claims (4)

A printing metal mask for printing a paste,
A flat mask body having two parallel upper and lower surfaces;
A recess is formed on a surface of the mask body facing a print substrate on the lower surface side thereof and recessed toward an upper surface side of the mask body.
a plurality of mesh holes, each of which is basically a diamond shape, formed within a print pattern area formed on the upper surface side of the mask body;
a metal mask for printing characterized in that the numerous mesh holes comprise large diamond-shaped mesh holes arranged in a large number in the center of the printing pattern area; small diamond-shaped mesh holes arranged on the outer periphery of the large diamond-shaped mesh holes and having a mesh hole area smaller than the area of the large diamond-shaped mesh holes in the center; home plate-shaped pentagonal mesh holes arranged on the outermost periphery excluding the corners of the printing pattern area and having the same area as the small diamond-shaped mesh holes in the outer periphery; and diamond-shaped pentagonal mesh holes arranged in the corners of the printing pattern area and having a mesh hole area smaller than the area of the large diamond-shaped mesh holes in the center . 2. The printing metal mask according to claim 1 , wherein the diamond-shaped pentagonal mesh holes have a mesh hole area equal to a mesh hole area of the small rhombic mesh holes in the outer periphery. 3. The printing metal mask according to claim 1 or 2, characterized in that the small diamond-shaped mesh holes in the outer periphery are arranged in one vertical row , two vertical rows, or three vertical rows adjacent to both left and right end portions of the large diamond-shaped mesh holes, and are arranged in one horizontal row, two horizontal rows, or three horizontal rows adjacent to both top and bottom end portions of the large diamond-shaped mesh holes. 4. The printing metal mask according to claim 1, wherein the mesh hole area of the small diamond-shaped mesh holes in the outer periphery is 5 to 30% smaller than the mesh hole area of the large diamond-shaped mesh holes .

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