JP2023169628A - Suspended metal mask with dummy pattern, and method for producing suspended metal mask with dummy pattern - Google Patents

Abstract

To provide a suspended metal mask with a dummy pattern that is designed to obtain a printed material with little print blurring and thickness difference, by forming a metal film with little thickness difference in the vicinity of a printing opening pattern.SOLUTION: The present invention provides a suspended metal mask with a dummy pattern, in which a first layer is formed of a resin film 10 and a second layer is formed of a metal film 5. A dummy opening pattern 9 is formed so that the metal film 5 as the second layer is formed at least in the vicinity of a printing opening pattern 6 while projecting further to the printed surface side than the resin film 10 as the first layer, and the metal film 5 as the second layer surrounds a printing pattern 7; and the dummy opening pattern 9 is closed with the resin film 10 as the first layer to form a dummy pattern 8.SELECTED DRAWING: Figure 1

Description

The present invention relates to a suspended metal mask capable of forming a printed pattern with suppressed printing bleeding, and a method for manufacturing the same.

The screen printing method uses, for example, a screen plate in which desired pattern openings are formed with photosensitive resin or the like on a screen mesh stretched on a rectangular frame with an appropriate tension, and the screen is covered with a squeegee or the like through the pattern openings. This is a type of so-called stencil printing in which a desired pattern is formed on a printed material by extruding ink or paste onto the printed material. Since the screen printing method can form relatively fine patterns at low cost, it can be used, for example, for decorative printing such as printing frame parts of touch panels and various lens filters, various functional printing, and electrode formation printing for electronic components. It is used in various fields such as wiring printing for printed circuit boards. However, in the normal screen printing method, a printed pattern may deviate from a desired pattern, so-called printing bleeding may occur.
The occurrence of printing bleed causes problems such as poor appearance in decorative printing, and inability to obtain desired characteristics in electrode formation of electronic components, wiring of printed circuit boards, etc.
Therefore, a screen mask (Patent Document 1) has been proposed in which printing bleeding is suppressed by forming convex portions at least on the contours of the printed pattern. By forming a convex part on at least the outline of the printing pattern, the convex part comes into contact with the printing material first during printing, and printing pressure is applied locally to this part, thereby creating a step or uneven shape on the printing material. Even if there is, it fits well into these shapes, improves the sealing between the printing material and the printed pattern, and effectively suppresses the occurrence of printing bleed.

JP-A-2008-162197 (see claims section, detailed description of the invention section, and FIGS. 1 and 2) JP 2014-121804 A (see detailed description of the invention {0022} and FIG. 12)

As described in Patent Document 1, it is possible to suppress printing smearing to some extent by forming a convex portion on the contour of a portion where printing smearing is likely to occur. However, when the convex portion is formed from a photosensitive resin material, even with the technology of Patent Document 1, the printing pattern, that is, the pattern opening of the screen plate, is approximately If there is a pattern that bends at an angle from a perpendicular direction to a substantially parallel direction, it is difficult to suppress the occurrence of print smearing in the portion of the printed pattern that is substantially perpendicular to the printing direction near the bent portion of the pattern opening. It turned out to be.
As an example of the above-mentioned aperture pattern, a schematic front view of a screen plate having a frame-shaped aperture pattern as seen from the so-called printing surface side facing the printing material is shown in FIG. 7(a) as a prior art in this specification. A cross-sectional view is shown in FIG. 7(b), and the printed material is shown in FIG. 7(c). The screen plate is made by applying a photosensitive emulsion 22 to a screen mesh 21 stretched over a plate frame (not shown), exposing it to light using a mask for forming the first layer, and then coating a photosensitive emulsion 23 thereon. It is formed by performing exposure using a second formation mask. A pattern opening 24 is formed in the first layer forming mask. The pattern opening 24 is a frame-shaped opening having a bending part where the pattern opening 24 of the first layer is bent at an angle from a direction substantially perpendicular to the printing direction to a direction substantially parallel to the printing direction. A large number of these frame-shaped pattern openings 24 are arranged in a matrix in the X direction and the Y direction. In the mask for forming the second layer, the convex pattern 25 is formed near the outline of the large number of frame-shaped pattern openings 24 formed in the first layer. In general, when screen printing a pattern that has a bent part that bends at an angle from a direction substantially perpendicular to the printing direction to approximately parallel to the printing direction, the amount of printed matter coated especially near the bent part increases, and Printing smear is likely to occur on the downstream side of the opening. Therefore, an attempt was made to suppress the occurrence of printing smearing by forming a convex pattern 25 near the outline of the frame-shaped pattern opening 24, but as shown in FIG. 7(c), printing smearing could not be sufficiently suppressed. There wasn't. The cause of print bleeding was thought to be the flexibility of the photosensitive resin film and the low smoothness (also referred to as flatness) of the surface of the photosensitive resin film.
As a result of extensive research, the inventors of the present invention have found that the above problem can be solved by printing using a suspended metal mask in which the vicinity of the printing opening pattern is formed of a metal film. After forming a metal film on the printing surface side near the printed opening pattern by electrolytic plating, a photosensitive resin material is applied from the squeegee surface side and exposed to light, so that the photosensitive resin material covers at least a part of the metal film. Forms a film. This makes it possible to obtain a suspended metal mask in which the second layer is a metal film and the first layer is a photosensitive resin film.
The suspended metal mask produced by the above manufacturing method has a so-called convex shape in which the metal film near the printed aperture pattern protrudes beyond the photosensitive resin film, and combined with the high flatness characteristic of the metal film, printing bleed is suppressed. It became possible to create printed matter that However, when we observed the printed matter after printing, we found that although the printing bleeding was suppressed, we measured the thickness of the printed matter at several dozen points and found that the difference in thickness between the thickest and thinnest parts caused the convex parts to become photosensitive. It was confirmed that the printed matter was larger than that printed with a conventional screen plate formed with a resin film.
As a result of further intensive research, the inventors of the present invention have found that the difference in the thickness of the metal film has a large effect on the difference in the thickness of printed matter. When only the metal film near the printed opening pattern is formed by electrolytic plating, the area where the metal film is formed in the printing pattern part is small, that is, the pattern opening density becomes high, so a resist film is not formed on the matrix. The amount of area covered will be very large. Such a printing pattern is sometimes referred to as a negative pattern. On the other hand, since most of the periphery of the printing pattern is a metal film, the pattern opening density is low and the area on which the resist film is formed is reduced. This extreme difference in pattern aperture density between the printing pattern area and the printing pattern periphery causes a difference in current density during electrolytic plating, with the electrolytic plating being thicker in the center of the printing pattern and being thicker around the printing pattern. This causes a phenomenon in which the thickness of electrolytic plating becomes thinner toward the end. Therefore, as one method for suppressing the above-mentioned phenomenon, a method is known in which a dummy opening pattern having an opening is formed in the periphery of the printing pattern (Patent Document 2). When forming a printing pattern by electrolytic plating, a dummy opening pattern is formed over a range of 16 mm to 20 mm in the metal film portion around the pattern, and the dummy opening pattern is filled with emulsion to close it. . By intentionally forming an opening pattern around the printing pattern, it is possible to suppress an increase in the difference in electrolytic plating thickness between the central part of the printing pattern and the peripheral part of the printing pattern. However, as mentioned above, in the case of a printing pattern called a negative pattern in which the portion formed with a metal film is very small, the difference in the thickness of the metal film cannot be achieved by forming a dummy opening pattern over a range of 16 mm to 20 mm. was insufficient to suppress the Another possible method is to form a dummy aperture pattern over the entire area other than the printing pattern and fill the dummy aperture pattern with emulsion to close the dummy aperture pattern. There is a high possibility that pinholes will occur due to the emulsion blocking the pattern peeling off and opening. The occurrence of pinholes leads to a decrease in printing durability, which is one of the characteristics of suspended metal masks, and furthermore, the occurrence of pinholes causes printed matter to be transferred to areas that are not needed during printing, resulting in printing defects. This may cause a decrease in product yield.
The present invention has been made to solve the above-mentioned problems, and by forming a metal film with a small difference in thickness near the print aperture pattern, it is possible to obtain printed matter with a small difference in print bleeding and thickness. A suspended metal mask having a desired dummy pattern is provided.

A first invention of the present invention capable of achieving the above object is a suspended metal mask having a dummy pattern as described in claim 1, and is as follows.
In a suspended metal mask in which the first layer is formed of a resin film and the second layer is formed of a metal film, the second layer metal film protrudes more toward the printing surface than the first resin film, at least near the printing aperture pattern. At the same time, a dummy opening pattern is formed so that the second layer metal film surrounds the printing pattern, and the dummy opening pattern is closed with the first layer resin film to form a dummy pattern.

A second invention of the present invention capable of achieving the above object is a suspended metal mask having a dummy pattern as described in claim 2, which is as follows.
In addition to the invention as set forth in claim 1, when the minimum rectangular shape in which the printing pattern fits is set as the printing pattern external shape, the dummy pattern surrounds the printing pattern outside the printing pattern external shape. and is formed within a rectangular shape similar to the external shape of the printing pattern, which is larger than the external shape of the printing pattern.

A third invention of the present invention capable of achieving the above object is a suspended metal mask having a dummy pattern as described in claim 3, and is as follows.
In addition to the invention as set forth in claim 2, the dummy pattern is formed outside the external shape of the printing pattern so as to surround the printing pattern, and has a circumference that is 1.75 times the circumference of the external shape of the printing pattern. The configuration described above is formed within a rectangular shape similar to the external shape of the printing pattern having a circumference that is 2.45 times or less.

A fourth invention of the present invention capable of achieving the above object is a method of manufacturing a suspended metal mask having a dummy pattern as described in claim 4, which is as follows.
A method for producing a suspended metal mask obtained by pasting a metal mask and a screen mesh by plating, the method comprising: a resist formed as at least a printed aperture pattern on a matrix for electrolytic plating; and a resist formed as an aperture pattern for forming a resin film. A step of forming a resist and a resist for a dummy opening pattern, and forming a metal mask by an electrolytic plating method using a mother mold for electroplating in which the printed opening pattern, the opening pattern for resin film formation, and the dummy opening pattern are formed with resist. A step of bonding the metal mask and the screen mesh together by electrolytic plating, and a step of peeling off the mother mold for electrolytic plating and the resist from the metal mask, the printed aperture pattern and the resin film are formed. A step of forming an aperture pattern for formation and a dummy aperture pattern, and a step of filling at least the aperture pattern for resin film formation and the dummy aperture pattern with resin from the squeegee surface side to close the aperture pattern for resin film formation and the dummy aperture pattern portion. This is a configuration for producing a suspended metal mask having a dummy pattern that can transfer a printed matter from a printing aperture pattern to a printing substrate.

The suspended metal mask having a dummy pattern and the method for manufacturing a suspended metal mask having a dummy pattern according to the present invention have the configuration as described above, and therefore have the effects described below.
(1) The first layer is formed of a resin film, the second layer is formed of a metal film, and the second layer of metal film protrudes further toward the printing surface than the first resin film, at least near the printing aperture pattern. Since it is formed as follows, it is possible to obtain printed matter with suppressed bleeding. Furthermore, since the dummy pattern is formed to surround the printing pattern, the difference in the thickness of the metal film is suppressed, and a printed matter with a small difference in thickness can be obtained.
(2) A dummy pattern is formed outside the printing pattern external shape so as to surround the printing pattern, with a minimum rectangular shape in which the printing pattern can fit, as the printing pattern external shape, and a dummy pattern is formed around the printing pattern external shape. The difference in the thickness of the second layer metal film can be suppressed by forming it in a rectangular shape similar to the external shape of the printing pattern having a circumference of 1.75 times or more and 2.45 times or less of the length. At the same time, since the range of the dummy pattern can be minimized, it is possible to suppress the generation of pinholes due to peeling off of the resin film blocking the dummy opening pattern and openings.
(3) After forming the second layer metal film on the printing surface side, a photosensitive resin material is applied from the squeegee surface side and exposed, thereby forming the first layer resin film and forming the dummy opening pattern. Since resin can be filled at once, work efficiency is improved.

FIG. 1 is a schematic front view (a) of a suspended metal mask having a dummy pattern according to an embodiment of the present invention as seen from the printing surface side, and (b) a schematic cross-sectional view taken along the line BB. FIG. 2 is a schematic front view of a printing pattern seen from the printing surface side of a suspended metal mask having a dummy pattern according to the present invention. A schematic enlarged view (a) of the CC section in FIG. 2, a schematic cross-sectional view (b) of the CC section in FIG. 2, and a schematic cross-sectional view of the boundary between the printing pattern and the dummy pattern in the D-D section of FIG. (c). Table (a) shows a schematic front view of a metal film on which no dummy pattern is formed and the thickness of the metal film within the printing pattern. Table (b) shows a schematic front view of the metal film and the thickness of the metal film in the printing pattern when the circumference is taken, and the dummy pattern formation range is 2.45 times the circumference of the printing pattern. It is a table (c) showing a schematic front view of the metal film and the thickness of the metal film in the printing pattern when it is made long. FIG. 3 is a schematic front view showing the external shape of a dummy pattern having a cross-shaped shuriken shape extending from the center of the metal film toward the four corners of the printing pattern. FIG. 3 is a process diagram illustrating a method for manufacturing a suspended metal mask having a dummy pattern according to the present invention. They are a schematic front view (a) showing a conventional technique, a cross-sectional view taken along the line AA (b), and a diagram (c) showing bleeding in a printed matter.

In a suspended metal mask in which the first layer is formed of a resin film and the second layer is formed of a metal film, the second layer metal film protrudes more toward the printing surface than the first resin film, at least near the printing aperture pattern. and a dummy opening pattern is formed so that the second layer metal film surrounds the printing pattern, and the dummy opening pattern is closed with a first layer resin film to form a dummy pattern. This is a suspended metal mask with a dummy pattern.

Hereinafter, one embodiment of the suspended metal mask of the present invention will be described based on the drawings.
Note that the dimensions such as thickness and width in FIGS. 1 to 7 of this embodiment do not represent the actual situation, but are shown schematically. Furthermore, it is understood that the present invention is not limited to the following embodiments, and that design changes, improvements, etc. may be made as appropriate based on the common knowledge of those skilled in the art without departing from the spirit of the present invention. It should be.
FIG. 1(a) is a schematic front view of an embodiment of a suspended metal mask 1 having a dummy pattern according to the present invention, viewed from the printing surface side, and FIG. 1(b) is a schematic cross-sectional view of the section BB. .

FIG. 1 shows a so-called combination type suspended metal mask in which a printing screen mesh 2 and a support screen mesh 3 are pasted together and stretched over a rectangular frame 4 via the support screen mesh. A metal film 5 called a metal mask is pasted on the side of the printing screen mesh 2 that faces the printing material, the so-called printing surface side, and a printing aperture pattern (not shown) is attached approximately at the center of the metal film 5. A printing pattern 7 is formed, and a dummy pattern 8 is formed to surround the printing pattern 7. A dummy opening pattern (not shown) is formed in the metal film 5 portion of the dummy pattern 8, and the opening is closed with a resin film (not shown) from the side where the squeegee is scanned during printing, the so-called squeegee side. has been done.
The size of the rectangular frame 4 is, for example, X450 mm x Y450 mm, and the width of the rectangular frame 4 is 30 mm. The printing screen mesh 2 is, for example, a calendered stainless steel screen mesh, the support screen mesh 3 is, for example, a polyester screen mesh, and both the printing screen mesh 2 and the support screen mesh 3 are stretched, for example, on a bias. The metal film 5 is made of a nickel alloy by electrolytic plating, and has, for example, a size of 290 mm x 290 mm and a thickness of 13 μm.The adhesive plating 11 for fixing the metal film 5 to the printing screen mesh 2 is made of nickel by electrolytic plating. The thickness is, for example, 1 μm.

FIG. 2 is a schematic front view of the printing pattern 7 and its surroundings as seen from the printing surface side. In the printing pattern 7, six frame-shaped printing aperture patterns 6 are arranged in the X direction and nine in the Y direction. Further, an outline 12 is formed to surround the printing pattern 7, and a dummy pattern 8 is further formed outside the outline 12. Note that the dummy pattern 8 has the same shape as the frame-like pattern of the printing pattern 7.

3(a) is a schematic enlarged view of the section CC in FIG. 2, FIG. 3(b) is a schematic sectional view of the section CC in FIG. 2, and FIG. 3(c) is a schematic sectional view of the section DD in FIG. FIG. 2 is a schematic cross-sectional view of a boundary between a printing pattern 7 and a dummy pattern 8. FIG. As shown in FIGS. 3(a) and 3(b), the suspended metal mask 1 having a dummy pattern of the present invention has a lattice-shaped metal film 5 on the printing surface side of the periphery of the frame-shaped printed opening pattern 6. A frame-shaped metal film 5 is formed, and a resin film 10 is formed on the inner periphery of the frame-shaped metal film 5 from the squeegee surface side, and the metal film 5 is closer to the printing surface side than the resin film 10. The shape is such that it is formed at least near the printing aperture pattern 6 in a protruding state. Further, as shown in FIG. 3C, a resin film 10 is also formed on the dummy pattern 8, and the dummy opening pattern 9 is closed with the resin film 10.
As shown in FIGS. 3(a) and 3(b), the area occupied by the metal film 5 within the printing pattern 7 is very small. Therefore, if the dummy pattern 8 is not formed within a certain range so as to surround the printing pattern 7, the thickness of the metal film 5 near the center of the printing pattern 7 and the thickness of the metal film 5 around the printing pattern 7 will be different. The difference becomes larger.
FIG. 4(a) shows a schematic front view of the metal film 5 on which no dummy pattern is formed and a table showing the thickness of the metal film 5 in the printing pattern 7, and FIG. 4(b) shows the circumference of the printing pattern 7. FIG. 4C shows a schematic front view and a table showing the thickness of the metal film 5 in the printing pattern 7 when the dummy pattern 8 having a circumference 1.75 times that of the printing pattern 7 is formed. A schematic front view of a dummy pattern 8 having a circumferential length 2.45 times that of the circumferential length of FIG.
Depending on the printing purpose, the outermost printing pattern 7 may be arranged flush as shown in FIG. 2, or the outermost printing pattern 7 may be uneven (not shown) depending on the printing purpose. Sometimes they are arranged in a shape. Therefore, in the present invention, the minimum rectangular shape in which the printing pattern 7 can fit is defined as the printing pattern external shape 13, and the circumference of the minimum rectangular shape in which the printing pattern 7 can fit is defined as the circumference of the external shape of the printing pattern 7. Although there is no particular restriction on the circumferential length of the printing pattern external shape 13, in order to obtain high effects of the present invention, it is desirable that the circumferential length of the printing pattern external shape 13 is 236 mm or more.
Further, the range in which the dummy pattern 8 is formed is within a similar shape to the printing pattern external shape 13 having a rectangular shape, and the similar shape is approximately parallel to each opposing side of the printing pattern external shape 13, and the center of gravity is is arranged so that it is at the same position as the center of gravity of the printing pattern external shape 13.
In this embodiment, the printing pattern external shape 13 is a rectangular shape shown by the dashed-dotted line in FIG. There is. The printing pattern external shape 13 of this example is a square with lengths of side a, side b, side c, and side d of 75 mm, and the perimeter is 300 mm, which is the total length of each side. There is. Therefore, when the printing pattern appearance shape 13 of this example is multiplied by 1.75 times or 2.45 times, the appearance shape and circumference are as follows: It becomes 525 mm, and when magnified by 2.45, it becomes a square with one side of 183.75 mm and a circumference of 735 mm.
The dummy pattern 8 and the printing pattern 7 are spaced at an appropriate distance to prevent the printed opening pattern 6 near the dummy pattern 8 from being erroneously closed with the resin film 10 when the dummy opening pattern 9 is closed with the resin film 10. Since it is desirable to form the pattern with an opening, an outline 12 as shown in FIG. 2 is formed between the printing pattern 7 and the dummy opening pattern 9. Regarding the width W of the outline 12, if the printing pattern 7 and the dummy opening pattern 9 are spaced widely, the effect of the dummy pattern 8 will be weakened, so the width W of the outline 12 is preferably 200 μm or more and 2000 μm or less. The width W of the outline 12 in this embodiment is 300 μm.
There are no particular restrictions on the opening shape or arrangement interval of the dummy pattern 8, and any opening shape or arrangement shape may be used, but the opening ratio per unit area when forming the metal film 5 in the printing pattern 7 is the standard. It is desirable to have an aperture ratio per unit area close to that. For example, if the aperture shape and arrangement interval of the dummy pattern 8 are configured by the pattern aperture shape and arrangement interval of the printing pattern 7, the above-mentioned conditions are satisfied, the arrangement of the dummy pattern 8 is facilitated, and the effect of the dummy pattern 8 is also improved. This is preferable because it can be obtained in sufficient quantity. In this embodiment, the opening shape and arrangement interval of the dummy pattern 8 are configured to be the same as the frame-like pattern opening shape and arrangement interval of the printing pattern 7.

In this example, the thickness of the metal film 5 in the printing pattern 7 is measured by measuring the thickness of each of the metal films 5 in a total of 54 frame-shaped patterns, six in the X direction and nine in the Y direction. . In Figures 4(a), 4(b), and 4(c), the frame-shaped pattern at the top left is (1, 1) and the frame-shaped pattern at the bottom right is (6, 9). In addition to recording the measured values of the thickness of the 54 metal films 5, the maximum value of the thickness is max, the minimum value of the thickness is min, the difference between max and min is range, and the average value of the measured values at 54 locations is AVG. The standard deviation of the measured values is shown as σ. All units are μm.
As is clear from the measurement results of the thickness of the metal film 5 in FIGS. 4(a), 4(b), and 4(c), the thickness of the metal film 5 without the dummy pattern 8 is the thickness of the central portion. It can be seen that there is a tendency for the pattern to be thick and to become thinner toward the periphery, and that this tendency is suppressed by widening the area in which the dummy pattern 8 is formed. The range, which is an index of the difference in thickness of the metal film 5, is 5.8 μm without the dummy pattern 8, but when the dummy pattern 8 is arranged within a circumference that is 1.75 times the outer shape of the printing pattern 13. When the dummy pattern 8 is arranged within a circumference that is 2.45 times that of the printing pattern external shape 13, the value becomes 1.8 μm, which is 4 μm higher than when the dummy pattern 8 is not used. It's getting smaller. In addition, the standard deviation σ, which indicates the variation in the thickness of the metal film 5, was 1.39 without the dummy pattern 8, whereas it was 1.01 at 1.75 times, and 0.46 at 2.45 times. It can be seen that the difference in the thickness of the metal film 5 is reduced by expanding the range in which the dummy pattern 8 is formed.
As described above, the dummy pattern 8 can be formed within a range in which the circumference of the rectangular shape of the dummy pattern external shape is 1.75 times or more and 2.45 times or less of the circumference of the rectangular shape of the printing pattern external shape 13. , the uniformity of the thickness of the metal film 5 within the printing pattern 7 can be improved.
Note that since the dummy pattern 8 only needs to be formed within the range of a rectangular shape having the above-mentioned circumference, the dummy pattern external shape 13 may have various shapes as long as it is within the range of the above-mentioned rectangular shape. For example, as shown in FIG. 5, the external shape may be a cross-shaped shuriken extending from the center of the metal film 5 toward the four corners of the printing pattern 7.

Next, a method for manufacturing a suspended metal mask having a dummy pattern according to the present invention will be described.
6(a) to 6(j) are process diagrams illustrating a method for manufacturing a suspended metal mask having a dummy pattern according to the present invention, taking the section DD in FIG. 2 as an example.
As shown in FIG. 6(a), a resist film 15 is formed on a conductive electroforming master mold 14. As shown in FIG. Although it is common to use a stainless steel material such as SUS301 or SUS304 as the conductive electroforming mother mold 14, any material may be used as long as it can be used as the electroforming mother mold 14. The resist film 15 can be formed by laminating a film photoresist such as a dry film resist using an existing laminator, or by applying a liquid resist using an existing liquid resist such as a roll coater, spin coater, or curtain coater. There is a method of forming a liquid resist film on the electroforming mother mold 14 using a device, but any method is sufficient as long as the resist film 15 can be formed on the electroforming mother mold 14 to a desired thickness. Resists can be broadly classified into negative type resists and positive type resists, but any type may be used. Here, a negative type dry film resist is laminated onto the electroforming mother mold 14. Note that, regarding the thickness of the resist film 15, an appropriate thickness is used in accordance with the thickness of the metal film 5.

As shown in FIG. 6(b), a pattern is exposed using an exposure device (not shown). The pattern includes at least a print aperture pattern within the print pattern, a resin film forming aperture pattern, and a dummy aperture pattern formed around the print pattern. In FIG. 6(b), after a photomask 16 made of a material such as glass or film is brought into close contact with the resist film 15, ultraviolet rays are applied to the resist film 15 using a light source that generates ultraviolet rays such as an ultra-high pressure mercury lamp or a metal halide lamp (not shown). Although a method such as irradiation is shown, it is also possible to expose by a method of directly writing a pattern on the resist film 15 without using a photomask 16 using a direct writing device having a semiconductor laser, LED, or ultra-high pressure mercury lamp as a light source. Any exposure method may be used as long as the desired pattern can be exposed. Note that for the mask and drawing pattern for contact exposure, either a negative pattern or a positive pattern is selected depending on the type of photoresist. Here, since a negative type resist is used in which the exposed portion remains as a patterned resist film 17, a negative pattern photomask is used for exposure.

As shown in FIG. 6(c), the exposed resist film 15 is developed and dried to form a patterned resist film 17. The pattern resist film 17 includes the printing opening pattern 6 in the printing pattern 7, the resin film forming opening pattern 19 that will be closed with the resin film 10 in a later process, and the dummy opening pattern formed to surround the printing pattern 7. A shape such as 9 is formed.
As shown in FIG. 6D, the electroforming mother mold 14 on which the patterned resist film 17 has been formed is transferred to an electroforming bath (not shown), and electrolytic plating is performed to form the metal film 5. There are no particular restrictions on the plating bath used for electrolytic plating, and any known plating bath such as a nickel sulfamate bath or a nickel sulfate bath may be used. There are no particular restrictions on the metal used, but nickel or a nickel alloy such as a nickel-cobalt alloy is preferred. Furthermore, it is preferable to conduct electrolytic plating at a low current density of 0.1 to 2.0 A/dm ² in order to improve the uniformity of the plating amount as much as possible. Here, electrolytic plating of nickel alloy is performed to form a first electrolytic plating layer that will become the metal film 5 on the surface of the electroforming master mold 14 that is not covered with the pattern resist film 17. In addition, this first electrolytic plating layer 5 will form a second electrolytic plating layer 11 in a state in which it is brought into close contact with the printing screen mesh 2 in a later step, so that the first electrolytic plating layer 5 and the second electrolytic plating layer 11 are combined. It is preferable that the thickness of the patterned resist film 17 and the thickness of the first electrolytic plating layer 5 be approximately uniform so that the printing screen mesh 2 can adhere easily. As long as the plating layer 11 can be fixed, the thickness of the pattern resist film 17 and the thickness of the first electrolytic plating layer 5 may be different. Further, in order to make the thickness of the patterned resist film 17 and the thickness of the first electrolytic plating layer 5 substantially uniform, polishing or the like may be performed.

As shown in FIG. 6(e), a pattern resist of the electroforming mother mold 14 is formed by using a jig or the like (not shown) to place a printing screen mesh 2 stretched over a rectangular frame body 4 (not shown) with appropriate tension in advance. The membrane 17 and the first electrolytic plating layer 5 are brought into close contact with each other. The printing screen mesh 2 stretched over the rectangular frame 4 used at this time may be a so-called "straight screen" in which the printing screen mesh 2 is stretched directly onto the rectangular frame 4 with appropriate tension. A so-called "combination screen" in which a printing screen mesh 2 as shown in FIG. 1 is stretched over a rectangular frame 4 with appropriate tension via a support screen mesh 3 may also be used. If you use a straight screen, you will get a straight suspended metal mask, and if you use a combination screen, you will get a combination suspended metal mask. Note that herein, the straight suspended metal mask and the combination suspended metal mask are collectively referred to as the suspended metal mask. In any case, the printing screen mesh 2 where the first electrolytic plating layer 5 is pasted with the second electrolytic plating layer 11 may be made of stainless steel screen mesh, tungsten or tungsten alloy screen mesh, or nickel electroplating method. A conductive screen mesh such as the prepared screen mesh is used.

As shown in FIG. 6(f), a conductive printing screen mesh 2 is placed on the side of the electroforming mold 14 on which the pattern resist film 17 and the first electrolytic plating layer 5 are formed using a jig or the like (not shown). The second electrolytic plating layer 11 is formed by plating from the printing screen mesh 2 side while the mesh is in close contact with the printing screen mesh 2, and the first electrolytic plating layer 5 and the second electrolytic plating layer 11 are fixed and integrated. The second electrolytic plating layer 11 is also referred to as adhesive plating 11. The electrolytic plating bath (not shown) used to form the second electrolytic plating layer 11 is not particularly limited as in FIG. 6(d), and the electrolytic plating bath used in FIG. 6(d) may be used, or a different type Electrolytic plating baths may also be used. Any metal may be used for electrolytic plating, but nickel or a nickel alloy such as a nickel-cobalt alloy is preferred. Here, electrolytic plating of nickel was performed using an electrolytic plating bath different from the electrolytic plating bath used in FIG. 6(d) to form the second electrolytic plating layer 11.

As shown in FIG. 6(g), the printing screen mesh 2 and the first electrolytic plating layer 5 integrated with the second electrolytic plating layer 11 are peeled off from the electroforming mold 14, and the pattern resist film that is no longer needed is removed. 17 is removed. At this point, the first electrolytic plating layer 5 is formed on the printing surface side, that is, a suspended metal mask having the metal film 5 on the printing surface side is formed. However, the resin film forming opening pattern 19 in the printing pattern 7 and the dummy opening pattern 9 in the dummy pattern 8 remain open.

As shown in FIG. 6(h), the photosensitive resin material 18 is coated from the squeegee surface side until the desired thickness is reached by a known screen printing photosensitive resin coating method using a bucket (not shown) or the like. do. The photosensitive resin material 18 to be used is not particularly limited as long as it is a photosensitive resin, but a photosensitive resin material for screen printing can be suitably used. At this time, the surface of the photosensitive resin material 18 may be smoothed (sometimes referred to as flat processing).

As shown in FIG. 6(i), exposure is performed so as to close at least the closed portions of the resin film 10 in the printing pattern 7 and the closed portions of the resin film 10 in the dummy pattern 8. As shown in FIG. Any exposure method that can be used in the step of FIG. 6(b) may be used as the exposure method. At this time, as shown in FIG. 6(i), the outer periphery of the closed part of the resin film 10 in the printing pattern 7 is formed without shifting from the position of the frame-shaped pattern of the metal film 5 formed by the first electrolytic plating layer. However, as shown in FIGS. 3(b) and 3(c), at least the resin film 10 is As long as the closed portion can be closed, it does not matter even if the position of the metal film 5 is misaligned with the frame-shaped pattern, or even if the closed area of the resin film 10 is smaller than the outer periphery of the frame-shaped pattern of the metal film 5. do not have.

As shown in FIG. 6(j), by developing the photosensitive resin material and removing unnecessary photosensitive resin material, the first layer is formed of the resin film 10 and the second layer is formed of the metal film 5. , the second layer metal film 5 is formed at least in the vicinity of the printing aperture pattern 6 in a state that protrudes toward the printing surface side than the first layer resin film 10, and the first layer resin film 10 is formed so as to surround the printing pattern 7. A suspended metal mask 1 having a dummy pattern, which has a closed dummy opening pattern 9, can be obtained. If necessary, functional materials such as liquid repellency or hydrophilicity may be applied to the suspended metal mask 1 having the obtained dummy pattern by an appropriate method, or the resin film or metal film may be coated with an appropriate surface roughness. may be formed.

The present invention can also be used in suspended metal masks having a so-called negative pattern with a large pattern opening area, and in various screen printing fields where suppression of print bleeding is required.

1...Suspended metal mask with dummy pattern 2...Screen mesh for printing 3...Support screen mesh 4...Square frame 5...Metal film (first electrolytic plating layer)
6...Printed aperture pattern 7...Printing pattern 8...Dummy pattern 9...Dummy aperture pattern 10...Resin film 11...Paste plating (second electrolytic plating layer)
12... Outline 13... Printing pattern external shape 14... Electroforming matrix 15... Resist film 16... Photomask 17... Pattern resist film 18... ... Photosensitive resin material 19 ... Opening pattern for resin film formation

Claims (4)

In a suspended metal mask in which the first layer is formed of a resin film and the second layer is formed of a metal film, the second layer metal film protrudes more toward the printing surface than the first resin film, at least near the printing aperture pattern. and a dummy opening pattern is formed so that the second layer metal film surrounds the printing pattern, and the dummy opening pattern is closed with a first layer resin film to form a dummy pattern. A suspended metal mask with a dummy pattern. When the minimum rectangular shape in which the printing pattern fits is set as the printing pattern external shape, the dummy pattern is formed outside the printing pattern external shape so as to surround the printing pattern, and the printing pattern external shape is The suspended metal mask having a dummy pattern according to claim 1, wherein the suspended metal mask is formed in a rectangular shape similar to the external shape of the printing pattern, which is larger than the outer shape of the printing pattern. The dummy pattern is formed outside the external shape of the printing pattern so as to surround the printing pattern, and has a circumference of 1.75 times or more and 2.45 times or less of the circumference of the printing pattern external shape. 3. The suspended metal mask having a dummy pattern according to claim 2, wherein the dummy pattern is formed in a rectangular shape similar to the external shape of the printing pattern. A method for producing a suspended metal mask obtained by pasting a metal mask and a screen mesh by plating, the method comprising: a resist formed as at least a printed aperture pattern on a matrix for electrolytic plating; and a resist formed as an aperture pattern for forming a resin film. A step of forming a resist and a resist for a dummy opening pattern, and forming a metal mask by an electrolytic plating method using a mother mold for electroplating in which the printed opening pattern, the opening pattern for resin film formation, and the dummy opening pattern are formed with resist. A step of bonding the metal mask and the screen mesh together by electrolytic plating, and a step of peeling off the mother mold for electrolytic plating and the resist from the metal mask, the printed aperture pattern and the resin film are formed. A step of forming an aperture pattern for formation and a dummy aperture pattern, and a step of filling at least the aperture pattern for resin film formation and the dummy aperture pattern with resin from the squeegee surface side to close the aperture pattern for resin film formation and the dummy aperture pattern portion. 1. A method for manufacturing a suspended metal mask having a dummy pattern, which is characterized in that printed matter can be transferred from a printed aperture pattern to a substrate by having a dummy pattern.

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