JP7125533B1 - Manufacturing method of metal mask for printing - Google Patents

Abstract

[PROBLEMS] To print a fine print pattern having a curved portion with high quality, suppress breakage of a mesh opening for holding a printing opening, and have a high structural strength and a complicated printing pattern including a curved portion. To provide a metal mask for printing capable of properly retaining the shape of a printing opening even with a shaped print pattern. SOLUTION: The metal mask for printing is formed of a two-layer structure of a first metal layer and a second metal layer, the second metal layer has printing openings corresponding to a printing pattern, and the first metal layer has A plurality of mesh openings are formed to hold the printing openings, the mesh openings connecting with the printing openings to form through-holes, one corresponding to the inside of the curved portion and one corresponding to the outside. It is formed to be equal to or larger than [Selection] Fig. 2

Description

The present invention provides a printing metal for printing conductive paste such as silver paste or insulating paste such as glass paste (hereinafter referred to as "conductive paste, etc.") on a work such as a substrate, wafer, or green sheet. It concerns masks.

In printed electronics, in which electronic circuits and electronic components are formed by printing conductive paste or the like on a substrate, in general, printed patterns are printed on the surface of a mask base material, which is a thin metal plate, as shown in FIG. Conventionally, a printing plate 100 has been used in which a printing metal mask 101 having printing openings 102 of a corresponding shape and size is stretched over a metal frame F by a screen mesh S.

Here, when forming a complicated and fine print pattern including a curved portion, as typified by printed electronics, the print opening 102 also has a complicated shape correspondingly. A structure is required to hold the

Therefore, as shown in FIG. 10, a screen mesh S made of stainless steel and a metal mask 101 for printing adhered thereto by nickel electroplating has been widely used (see, for example, Patent Document 1). FIG. 10 shows the printing opening 102 of the printing metal mask 101 viewed from the printing surface (the side facing the object to be printed).

In this form, the shape of the printing openings 102 is maintained by the tension of the screen mesh S, and the conductive paste or the like is transferred to the printing material through the mesh openings 103, which are the gaps between the screen meshes S.

In this case, the screen mesh S is woven in a uniform pattern, while the printing apertures 102 have various and complex shapes, such as to form a printing pattern having curvilinear portions. As shown in FIG. 10, the mesh opening 103 becomes very small locally, particularly at the curved portion of the opening 102, and there is a problem that the conductive paste or the like cannot be printed properly. This is particularly noticeable when the print pattern is minute and the thickness of the lines of the mesh screen S is not negligible with respect to the size of the printing openings 102 .

On the other hand, as shown in FIG. 11, the metal mask 201 for printing has a multi-layered structure in which the first metal layer M1 and the second metal layer M2 are adhered and integrated. A method of forming the printing openings 202 in the metal layer M2 and holding the printing openings 202 with the bridging portions 204 is also used (see, for example, Patent Document 2).

In this case, the screen mesh S is stretched on the metal frame F by applying tension to the metal mask 201 for printing to form a printing plate (not shown), but is fixed to the four sides of the metal mask 201 for printing. The portion covered inside the printing metal mask 201 is removed in the manufacturing process, and unlike the printing metal mask 101 , it does not have a structure that covers the printing opening 202 .

Here, the conductive paste or the like is applied to the mesh openings 203 formed by the bridging portions 204 (if necessary, the non-curved portion is the mesh opening 203a, the inside of the curved portion is the mesh opening 203b, and the outside of the curved portion is the mesh opening 203c). However, in the case of a structure in which the printing openings 202 are minute and have curved portions, the mesh openings 203b inside the curved portions become extremely small, and the conductive paste or the like is transferred to the printed material. becomes difficult to pass through, resulting in poor print quality.

On the other hand, if the cross-linking portions 204 are narrowed, spaced apart, or reduced in number in order to improve the passability of the conductive paste or the like, the tension of the screen mesh S and the pressure of the squeegee during printing may cause individual cross-linking. Since the load applied to the bridging portion 204 increases, the bridging portion 204 is easily broken, resulting in a reduction in the structural strength of the metal mask 201 for printing.

JP 2015-217641 JP 2021-066067

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide a method of manufacturing a metal mask for printing, which can print a fine and complicated print pattern having curved portions with high quality.

Another object of the present invention is to provide a method of manufacturing a printing metal mask having high structural strength by suppressing breakage of mesh openings for holding printing openings corresponding to such printing patterns.

Another object of the present invention is to provide a method of manufacturing a metal mask for printing, which can properly maintain the shape of the printing opening even in a printing pattern having a complicated shape including curved portions.

The invention according to claim 1 is a method for manufacturing a printing metal mask for forming a printing pattern having curved portions, wherein a first resist layer is formed on a conductive substrate in a predetermined pattern by photolithography. forming a first metal layer having mesh openings corresponding to the first resist layer on the conductive substrate by electroplating; and forming a first metal layer on the first metal layer by photolithography forming a second resist layer having a size and shape corresponding to the printing pattern; and forming a second metal layer on the first metal layer by electroplating to have printing openings corresponding to the second resist layer. forming a layer integrally with said first metal layer; removing said first resist layer and said second resist layer to expose said mesh openings and said printing openings; and peeling the second metal layer from the conductive substrate, wherein the mesh openings are smaller than the printing openings and cover part or all of the printing openings including portions corresponding to the curved portions. while being formed so as to cover the curved portion, the one arranged inside the curved portion is formed to be equal to or larger than the one arranged outside.
The invention according to claim 2 is the method for manufacturing a metal mask for printing according to claim 1, wherein the print pattern is a thin line shape, a doughnut shape, a circular shape, a polygonal shape, or a combination thereof. It is characterized by

According to the invention of claims 1 and 2 , in order to maintain the shape of the opening for printing, instead of the mesh woven in a fixed pattern, an arbitrarily designed mesh opening is installed, so that the conductive The space through which the paste or the like passes has little variation, and printing quality can be improved.

In addition, since some or all of the mesh openings of the curved portion are equal to or larger than those corresponding to the outer side, a fine print pattern having curved portions is formed. Even in this case, it is possible to improve the print quality.

In addition, the mesh opening corresponding to the outside of the curved portion has more bridging parts than the inside, so it is possible to suppress breakage of the mesh opening and increase the structural strength of the metal mask for printing. Become.

According to the second aspect of the invention, the shape of the printing opening can be properly maintained even when forming a complicated and minute print pattern consisting of a fine line, doughnut, circle, polygon, or a combination thereof. It is possible to

1 is a schematic front view of a metal mask for printing according to Embodiment 1 of the present invention; FIG. 1 is a schematic front view (a) and a side (X ₁ -X ₁ ) cross-sectional view (b) of a printing opening and a mesh opening of a metal mask for printing according to Embodiment 1 of the present invention; FIG. 1 is a schematic process flow diagram showing a method of manufacturing a metal mask for printing according to Embodiment 1 of the present invention; FIG. 1 is a schematic process flow diagram showing a method of manufacturing a metal mask for printing according to Embodiment 1 of the present invention; FIG. FIG. 7 is a schematic front view of printing openings and mesh openings of a metal mask for printing according to Embodiment 2 of the present invention. FIG. 4 is a schematic front view of printing openings and mesh openings of a metal mask for printing according to another embodiment of the present invention; FIG. 4 is a schematic front view of printing openings and mesh openings of a metal mask for printing according to another embodiment of the present invention; FIG. 10 is a schematic front view (a) and a side (X ₂ -X ₂ ) cross-sectional view (b) of a printing opening and a mesh opening of a metal mask for printing according to another embodiment of the present invention; 1 is a schematic front view of a conventional printing plate; FIG. 1A and 1B are a schematic front view (a) and side (X ₃ -X ₃ ) cross-sectional view (b) of a printing opening and a mesh opening of a conventional metal mask for printing; FIG. 1A and 1B are a schematic front view (a) and a side (X ₄ -X ₄ ) cross-sectional view (b) of a printing opening and a mesh opening of a conventional metal mask for printing; FIG.

Embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings, the sizes, intervals, numbers, and other details of the configuration of each part in the drawings are greatly simplified compared to the actual ones to aid visual recognition and understanding.

Embodiment 1 of the invention
FIG. 1 is a schematic front view of a printing metal mask 1 according to Embodiment 1 of the invention. As shown in FIGS. 1 and 2, the metal mask 1 for printing includes a flat mask base material 11, printing openings 12 formed in the plane of the mask base material 11, and mesh openings formed in the same manner. 13. The mesh openings 13 are connected to the printing openings 12 to form through holes. Here, FIGS. 1 and 2 show the printing metal mask 1 and the printing opening 12 as viewed from the side facing the printed material, and the same applies to subsequent figures and embodiments.

The mask base material 11 is a quadrilateral (square or rectangular) metal flat plate having a side length of 200 to 800 mm. A first metal layer M1 that serves as a sliding surface (squeegee surface) and a second metal layer M2 that serves as a surface (printing surface) facing a printed matter are in close contact with each other to form a two-layer structure. The thickness of the first metal layer M1 is set to 5 to 100 μm, and the thickness of the second metal layer M2 is set to 1 to 200 μm.

The printing opening 12 is formed on one side of the mask base material 11 (the second metal layer M2 in this embodiment) so as to penetrate the second metal layer M2 with a size and shape corresponding to the printing pattern. formed. Further, in the first embodiment, it is substantially J-shaped and has a curved portion in a part thereof.

The printing openings 12 have a maximum dimension of about 0.03 to 1.0 mm, and are formed in plurality in the plane of the mask base material 11 as shown in the figure.

The mesh openings 13 are smaller than the printing openings 12 and are formed in the curved portions of the printing openings 12 in the surface of the mask base material 11 opposite to the printing openings 11 (the first metal layer M1 in this embodiment). In the same area as all of the printing openings 12 including the corresponding portions, a plurality of them are formed so as to cover the printing openings 12, and each side has a dimension of about 0.01 to 0.1 mm.

In addition, the area where the mesh openings 13 are formed is set small similarly to the shape of the printing openings 12, as in the case of the conventional printing plate. The metal layer M1 protrudes inside the printing opening 12 by about 0.001 to 0.03 mm.

The mesh opening 13 (hereinafter, the non-curved portion is hereinafter distinguished as mesh opening 13a, the inside of the curved portion as mesh opening 13b, and the outside of the curved portion as mesh opening 13c) is the non-curved portion of printing opening 12. The sizes of the mesh openings 13a are set to be substantially the same. formed larger.

Here, in Embodiment 1, the comparison of the size of the two mesh openings 13 is not simply based on the size of the area, but is based on the passability of conductive paste or the like during actual printing. It is determined by whether or not they can be superimposed so as to fit in the . That is, in Embodiment 1, when mesh opening 13c on the outside of the curve and mesh opening 13b on the inside are overlapped, mesh opening 13c fits inside 13b, so it is determined that mesh opening 13b is larger than 13c. On the other hand, when all the sides forming the mesh opening 13 are substantially the same, it is determined that the sizes are the same. Further, if some sides substantially overlap, but one remaining side lies inside the other, the latter is also greater than the former.

In order to maintain the shape of the printing apertures 12, the outline of the mesh apertures 13 is printed in the same area as all the printing apertures 12, including the portions corresponding to the curved portions of the printing apertures 12 in the first metal layer M1. It is formed by a bridging portion 14 formed to cover the opening 12 .

In Embodiment 1, the bridging portion 14 extends along the curved portion of the printing opening 12 and connects the short sides of the first metal layer M1 protruding inside the printing opening 12 to the bridging portion 14a. , and the bridging portions 14b extending in a direction intersecting these and similarly connecting the long sides of the first metal layer M1 to each other and connecting the bridging portions 14a to each other or the bridging portions 14a and the long sides of the first metal layer M1. , and a bridging portion 14c. The width of the bridging part 14 must be in a range that can ensure strength not to be broken during printing and that the conductive paste discharged from the adjacent mesh openings 13 can be connected without isolation. In Embodiment 1, it is about 0.01 to 0.1 mm.

The bridging portion 14c divides the mesh opening 13 formed by 14a and 14b and is arranged so that the mesh opening 13c on the outside of the curved portion is smaller than the mesh opening 13b on the inside.

Next, a method for manufacturing the metal mask 1 for printing will be described with reference to FIGS. In Embodiment 1, the printing metal mask 1 is manufactured using a photolithography method and an electroplating method.

First, a conductive substrate Sb, which is an electrode for electroplating and serves as a plating base on which plating is deposited, is prepared (a). For the conductive substrate, a suitable thickness and material are selected in consideration of handleability and stability in the plating solution during plating. there is Also, the size of the rectangle is selected to be an appropriate size in consideration of the size of the metal mask 1 for printing to be manufactured. In Embodiment 1, the long side of 650 mm and the short side of 550 mm are used.

Next, the conductive substrate is coated with a dry film of photoresist FR (b), the photoresist FR is exposed to the pattern of the mesh openings 13 by an exposing machine (c), and the unexposed film is exposed by a developing machine. The exposed portion is melted and removed to form the first resist layer R1 (d). Here, a direct writing type exposing machine was used in which light was directly irradiated onto the photoresist FR in a predetermined pattern without using a photomask. Here, the size, shape, and arrangement of the first resist layer R1 correspond to the mesh openings 13. FIG.

Next, a first metal layer M1 is formed by electroplating on the conductive substrate on which the first resist layer R1 is formed (e). A mesh opening 13 corresponding to the first resist layer R1 is formed in the first metal layer M1. Here, in the first embodiment, the electroplating method uses a plating solution based on nickel sulfamate.

Next, a dry film of photoresist FR is coated on the first metal layer M1 and the first resist layer R1 (f), exposed and developed, and a size corresponding to the printing pattern, that is, the printing opening 12 is formed. Form a second resist layer in shape and arrangement (g, h). Here, the second resist layer R2 is formed 0.001 to 0.03 mm outside the region where the mesh openings 13 are formed, so that the first metal layer M1 is positioned inside the printing openings 12. A protruding structure is formed.

Next, a second metal layer M2 is formed on the first metal layer M1 by electroplating. A printing opening 12 corresponding to the second resist layer R2 is formed in the second metal layer M2 (i). The second metal layer M2 is integrally formed in close contact with the first metal layer M1 to form the mask base material 11. As shown in FIG. Here, as described above, the mesh openings 13 are smaller than the printing openings 12 and are formed so as to cover part or all of the printing openings 12 including the portions corresponding to the curved portions of the printing openings. A part or all of what is arranged inside the curved portion is formed to be equal to or larger than what is arranged outside.

Next, the conductive substrate is immersed in a resist stripping solution to remove the first resist layer R1 and the second resist layer R2, thereby exposing the mesh openings 13 and the printing openings 12. FIG. In Embodiment 1, a caustic soda aqueous solution is used as the resist stripper.

Next, the mask base material 11 is separated from the conductive substrate to complete the printing metal mask 1 (j).

In Embodiment 1, the metal mask 1 for printing is used as a printing plate by being stretched over a metal frame F with a polyester mesh M interposed therebetween in the same manner as the printing plate described above.

According to this invention, in order to maintain the shape of the printing openings 12, instead of the mesh M woven in a fixed pattern, the arbitrarily designed mesh openings 13 are provided, so that conductive paste or the like is used. There is less partial variation in the space through which the ink passes, and it is possible to improve the printing quality.

In addition, in the mesh openings 13 of the curved portion, part or all of the mesh openings 13b corresponding to the inner side are formed to be equal to or larger than the mesh openings 13c corresponding to the outer side. It is possible to improve the print quality even in the case of forming a large print pattern.

In addition, since more bridging portions 14 are arranged in the mesh opening 13c corresponding to the outside of the curved portion than in the inside, breakage of the mesh opening 13c is suppressed, and the structural strength of the metal mask 1 for printing is increased. becomes possible.

Furthermore, the shape of the printing openings 12 can be properly maintained even when forming a complex and fine print pattern consisting of fine lines, doughnuts, circles, polygons, or a combination thereof.

Embodiment 2 of the invention
FIG. 5 is a schematic front view of printing openings 22 and mesh openings 23 of a printing metal mask 2 (not shown) according to Embodiment 2 of the invention. Here, in the second embodiment, illustrations and descriptions of elements common to the first embodiment are omitted. Also, the manufacturing method thereof is the same as that of the first embodiment.

The printing aperture 22 has a donut-like shape composed of two large and small concentric circles. It is

The mesh opening 23 has a substantially elliptical shape and is connected to the printing opening 22 to form a through hole. In Embodiment 2, the size of the mesh opening 23 is the same inside (that is, near the inner circle) and outside (near the outer circle) the curved portion of the printing opening 22, and the major axis is 0. 0.01 to 0.2 mm and the minor axis is 0.005 to 0.1 mm.

In addition, the area where the mesh openings 23 are formed is set small similarly to the shape of the printing openings 22, and is arranged concentrically with the inner and outer circles, as in the first embodiment. .

The printing opening 22 has a donut shape and is entirely composed of curved lines, and the mesh opening 23 is divided into the mesh opening 23 on the inner side of the curve (the side with the larger curvature) and the mesh opening 23 on the outside of the curve (the side with the smaller curvature). side).

The bridging portion 24 is formed continuously in the direction of a circle substantially concentric with the outer and inner circles of the printing opening 22, but on the other hand, has no particular directionality in the diameter direction and is irregularly formed. are placed.

According to the present invention, in order to maintain the shape of the printing openings 22, instead of the mesh M woven in a fixed pattern, the randomly designed mesh openings 23 are provided. There is less partial variation in the space through which the ink passes, and it is possible to improve the printing quality.

In addition, since all of the mesh openings 23 of the curved portion corresponding to the inner side are formed to have the same size as those corresponding to the outer side, when forming a printing pattern having a curved portion, It is also possible to improve print quality.

Furthermore, the shape of the printing openings 22 can be properly maintained even when forming a printing pattern having a fine line shape, a donut shape, a circular shape, a polygonal shape, or a combination thereof.

Although Embodiments 1 and 2 have been described above, the scope of the present invention is not limited to the above embodiments, and extends to other embodiments that can be regarded as equivalent thereto.

For example, the bridging portion 14 can take a form as shown in FIGS. Here, the description of the same configuration as that of the embodiment will be omitted unless particularly necessary.

In FIG. 6, mesh openings 33 (hereinafter, the non-curved portion is defined as mesh opening 33a, the inside of the curved portion as mesh opening 33b, and the outside of the curved portion as mesh opening 33c) are located inside the curved portion. The mesh opening 33b and the outer mesh opening 33c are set to have substantially the same size. For this reason, the size of the mesh openings 33b and 33c is adjusted by appropriately arranging the bridging portion 34c without providing a bridging portion 14b that connects the long sides. is also the same). As a result, it is possible to further reduce variations in the amount of printing between the inside and outside of the curved portion and improve the printing quality.

Further, as shown in FIG. 7, by disposing the bridging portions 44d along the direction of the curved portion at non-equidistant intervals, it becomes possible to finely adjust the sizes of the mesh openings 43b and 43c, and the It is possible to maintain good print quality even for the printing opening 44 having a large curved portion and the printing opening 44 having a curved portion with a large curvature.

Further, in Embodiment 2, rib portions 55 having the same thickness as the second metal layer M2 are formed in the bridging portions 54 of the first metal layer concentrically with the inner and outer circles of the printing openings 52. , it is possible to print finer curves.

Furthermore, the method of manufacturing the metal mask 1 for printing is not limited to the electroplating method, and an etching method, a laser processing method, an electroless plating method, or the like may also be used. For example, it is possible to manufacture the first metal layer M1 and the second metal layer M2 separately by etching or laser processing and joining them by electroplating. In addition, by using the electroless plating method, it is possible to eliminate variations in the thickness of the plated film that tend to occur when using the electroplating method. can be obtained.

In addition, in the above-described embodiment, the mesh opening 13 is provided over the entire printing opening 12, but it is not necessarily limited to this. It may be provided only in part of the printing opening 12 . As a result, design and manufacturing can be simplified, and productivity can be improved.

Moreover, when the curvature of the curved portion is small (that is, when the curve is loose), the mesh openings 13 corresponding to the inner side of the curved portion are not necessarily formed to be equal to or larger than those corresponding to the outer side. Alternatively, there may be only partial mesh openings 13 if desired. As a result, further simplification of design and manufacturing can be achieved, so that it is possible to further improve productivity.

Further, the printing openings 12 and the mesh openings 13 may be set corresponding to the printing of the printing pattern, which is thin line, donut-shaped, circular, polygonal, or a combination thereof.

In addition, the metal mask 1 for printing may be curved and joined at opposite sides to be used in a roll shape without being necessarily stretched over the metal frame F to form a combination plate.

Moreover, the photoresist FR used in the manufacturing method is not limited to a dry film, and a liquid resist may be used.

Further, the exposure of the photoresist FR is not limited to the direct writing type, and an exposure method using a photomask (Cr mask, glass mask, etc.) may be used.

1 metal mask for printing 11 mask base material 12, 22, 32, 42, 52 openings for printing 13, 23, 33, 43, 53 mesh openings 14, 24, 34, 44, 54 bridges

Claims (2)

A method for manufacturing a printing metal mask for forming a printing pattern having curved portions, comprising:
forming a first resist layer in a predetermined pattern on a conductive substrate by photolithography;
forming a first metal layer having mesh openings corresponding to the first resist layer by electroplating on the conductive substrate;
forming a second resist layer on the first metal layer by photolithography in a size and shape corresponding to the printed pattern;
forming a second metal layer having printing openings corresponding to the second resist layer integrally with the first metal layer by electroplating on the first metal layer;
removing the first resist layer and the second resist layer to expose the mesh opening and the printing opening, and stripping the first metal layer and the second metal layer from the conductive substrate; with
The mesh opening is smaller than the printing opening, is formed so as to cover part or all of the printing opening including the part corresponding to the curved part, and is arranged inside the curved part. , formed equal to or larger than those placed outside,
A method for manufacturing a metal mask for printing, characterized by: The printed pattern is a fine line shape, a donut shape, a circular shape, a polygonal shape, or a combination thereof.
The method for manufacturing a metal mask for printing according to claim 1, characterized by:

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