JP2003072021A - Metal mask for printing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inexpensively provide a metal mask which is excellent in the positional precision of a printed pattern during printing and has good printing properties based on the shape of the printed pattern and a high opening ratio. SOLUTION: The metal mask for printing is produced through a process in which the surface of a conductor substrate is exposed in a mesh shape, by forming the first resist pattern having a desired mesh shape on the smooth conductor substrate by a UV lithography method, and metal meshes 5 are formed on the exposed surface of the substrate by an electrocasting method; a process in which a thin metal film 6 is formed on the metal meshes 5 and the resist pattern, and after a pattern to be printed comprising the second resist pattern on the metal film 6 by the UV lithography method, and a composite electrocast metal body is formed on the pattern to be printed by the electrocasting method; and a process in which after a film-shaped composite comprising the metal body, the first and second resist patterns is peeled off from the substrate, and the first and second resist patterns are removed from the composite to produce the composite electrocast metal body.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a metal mask for printing.

[0002]

2. Description of the Related Art As a printing metal mask in which a mesh screen and a printing pattern forming metal layer are integrated, many proposals have been made so far and some of them have been put into practical use. There are the following three inventions as typical ones.

For example, as in Japanese Examined Patent Publication No. Sho 49-12285, it is a positive type in which metal plating is applied to both surfaces of a metal screen to crush the mesh and a photosensitive solution is applied to the upper surface of the plating layer for printing. There is a method of manufacturing a printing screen in which the plating layer of the image area is exposed by baking and development patterning, and is further corroded to make the image area ink-permeable (FIG. 4).

Further, as in Japanese Patent Laid-Open No. 63-203787, a resist is applied on one surface of a thin copper support, and an image is printed to remove the resist only on the image. The exposed copper surface is nickel-plated. To form a nickel image forming layer on the copper support layer, and if necessary, one surface of a stainless steel gauze or a metal-coated polyester gauze which is framed, and the resist as described above. With the nickel drawing line forming layer on the copper support layer, the surfaces of the copper support layer are not plated, and both are bonded by nickel plating, and the entire back surface of the gauze is coated with nickel metal. It consists of completely removing the copper supporting layer with an etchant that corrodes the metal but not the nickel and removes the residual resist to penetrate the image forming holes of the nickel image forming layer. There is a method of manufacturing a metal mask plate for printing.

Further, in Japanese Unexamined Patent Publication No. 8-225983, a rib core plate having a precision fine pattern having a large number of through holes and continuous ribs surrounding each through hole and having a rib-shaped cross section in a mesh shape, When manufacturing electroformed products that are formed with a coating layer that covers the front and back surfaces so as to cover all the meshes of the rib core plate, a rib core plate pattern is formed on the surface of the original plate made of an insulator when manufacturing electroformed products. Step of forming corresponding fine grooves, step of forming a conductive plating base in a matrix only in the grooves of the original plate, and step of electrodepositing rib core plate on the plating base in the grooves of the original plate And a step of peeling the rib core plate from the original plate, and a process of integrally electrodepositing a coating layer on the front and back surfaces of the rib core plate so as to block all the meshes of the rib core plate. There is a manufacturing method.

However, in the above first and second inventions, since the constituent mesh screen is woven, the printing pattern is deformed when the printing frame is stretched under a predetermined tension instead of being flat. Further, in these printing metal masks, since the opening pattern is formed by the etching method, the shape of the side surface of the opening cannot be formed smoothly, and the printing plate removability of high-viscosity printed matter is poor. Further, if a mesh screen having an aperture ratio of 60% or more is used to improve printability, the mechanical strength of the metal mask becomes insufficient, and printing with high positional accuracy cannot be obtained. In addition, when the print pattern is formed by the etching method, the plate thickness range of the print pattern is limited, so that the mask thickness is generally limited to a thin one.

Furthermore, in the above-mentioned third invention, for example, only the grooves are formed by mechanically rubbing the surface of the original plate after forming a conductive plating base on the surface of the original plate having grooves formed in a matrix. It is essential to selectively leave the conductive plating base. Therefore, especially in the case of a long printing plate, the product yield is extremely low and the cost is high.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems of the prior art, to provide excellent positional accuracy of a printed pattern even at the time of printing, a high aperture ratio and an excellent printed pattern shape. It aims to provide a metal mask having printability at low cost.

[0009]

According to the present invention, a first resist pattern having a desired mesh shape is formed on a smooth conductor substrate by a UV lithography method to expose the conductor substrate surface in a mesh shape, A step of forming a metal mesh on the surface of the exposed conductor substrate by electroforming; forming a metal thin film on the metal mesh and the resist pattern; and then forming a second resist pattern on the metal thin film by UV lithography. After forming a printing pattern, a step of forming a composite electroformed metal body on the printing pattern by an electroforming method, and a film-shaped composite body comprising the composite electroformed metal body and first and second resist patterns Is peeled from the conductor substrate, and then the first and second resist patterns are removed from the film-shaped composite body to produce the composite electroformed metal body. In the metal mask for printing.

In addition, the present invention provides the first and second film-shaped bodies.
The metal mask is characterized in that a step of adding a metal coating film by an electroforming method is further added to the composite electroformed metal body produced by removing the resist pattern.

Further, according to the present invention, the metal mesh surface of the composite electroformed metal body produced by removing the first and second resist patterns from the film body is further subjected to a metal vapor deposition method, an electroless plating method, or The metal mask is characterized by adding a step of adding a metal coating film by an electroforming method.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIGS. FIG. 1 schematically shows a part of a printing metal mask made of a composite electroformed metal body 20 in which a square electroformed metal mesh layer 5 of the present invention is joined via another metal thin film layer 6. It is a thing.

FIG. 1A shows a composite electroformed metal body 2 of the present invention.
It is an external appearance schematic diagram seen from the printing surface of the metal mask 30 for printing which consists of 0, and FIG.1 (b) is an external appearance schematic diagram from the squeegee surface of the composite electroformed metal body 20. FIG.

The desired shape of the electroformed metal mesh layer 5 is as follows.
A rectangle including a rhombus or a square may be used, but a hexagonal shape is more preferable for high aperture ratio. The aperture ratio is not particularly limited, but is in the range of 20 to 80%. Aperture ratio is 20%
In the following, the printability of high-viscosity printed matter, such as cream solder or high-viscosity resinous material, deteriorates. Further, if the opening ratio is 80% or more, the mechanical properties of the electroformed metal mesh layer 5 are deteriorated, which is not preferable. The plate thickness of the electroformed metal mesh layer 5 is preferably 10 μm or more. When it is 10 μm or less, mechanical properties are deteriorated, which is not preferable.

The metal thin film layer 6 which is an intermediate layer of the composite electroformed metal body 20 is a layer which joins the electroformed metal mesh layer 5 and the printed pattern electroformed metal layer 10. It is preferable that the plate thickness is 1 to 5 μm and the coefficient of thermal expansion is close to that of the electroformed metal mesh layer 5 and the printed pattern electroformed metal layer 10.

The plate thickness of the electroformed metal layer 10 forming the printed pattern is preferably 15 to 150 μm. Further, the adhesion to the electroformed metal mesh layer 5 increases in proportion to the contact area.

The manufacturing method of the present invention will be described with reference to FIG. FIG. 3A shows the conductor substrate 1 which is surface-finished and smoothed, and SUS304 is used as the material, but other metals such as stainless steel, copper and nickel may be used. The plate thickness is preferably 0.2 mm or more for handling. Also, the conductor substrate 1
Since the composite electroformed metal body 20 is peeled off more preferably, the surface roughness is preferably a smooth surface having an average roughness of 1.0 μm or less.

FIG. 3 (b) shows a state in which the first photoresist 2 is laminated on the conductor substrate 1 which has been subjected to surface conditioning and pretreatment in order to improve the adhesiveness of the photoresist. Although DFR is used as the photoresist, a liquid resist such as PMER N-D40P manufactured by Tokyo Ohka Kogyo Co., Ltd. may be used.

FIG. 3 (c) shows a state in which UV exposure is performed using the first photomask 3 which is a glass mask having a desired metal mesh negative pattern. First
The photomask 3 has PET having the above negative pattern.
A film may be used. The exposure device may be parallel light or diffused light.

FIG. 3D shows a first resist pattern 4 formed by alkali development after UV exposure. Figure 3
(E) shows a plate thickness of 20 to 40 μm on the exposed conductor substrate 1.
Electroless nickel plating is applied to form the electroformed metal mesh layer 5. The plating material may be a metal such as copper, alloy or iron.

FIG. 3 (f) shows a metal thin film layer 6 formed on the electroformed metal mesh layer 5 and the first resist pattern 4 by electroless nickel plating having a plate thickness of 1 to 5 μm to be an electrode film. Is. The metal thin film layer 6 may be formed by electroless plating, vapor deposition or the like. Further, the metal thin film material may be a metal such as copper, iron or chromium.

FIG. 3 (g) shows the second photoresist 7 laminated on the pretreated metal thin film layer 6. Although DFR is used as the photoresist, the liquid resist as described above may be used.

FIG. 3 (h) shows a second glass mask.
It shows a state where UV exposure is performed using the photomask 8. A PET film may be used for the second photomask 8. The exposure device may be parallel light or diffused light.

FIG. 3 (i) shows a second resist pattern 9 formed by alkali development after UV exposure. Figure 3
(J) has a plate thickness of 15 to 100 on the exposed metal thin film layer 6.
The printed pattern electroformed metal layer 10 is formed by performing electrolytic nickel plating of μm. Plating material is copper, alloy,
A metal such as iron may be used.

FIG. 3 (k) shows FIGS. 3 (a) to 3 (j).
The first resist pattern 4 and the second resist pattern manufactured in the steps up to
The film-shaped composite body in which the resist pattern 9 and the composite electroformed metal body 20 are integrated is separated from the conductor substrate 1.

In FIG. 3 (l), the film-shaped composite body peeled from the conductor substrate 1 is immersed in an alkaline stripping solution to remove the first and second resist patterns, and the electroformed metal mesh layer 5 and the metal thin film are formed. The layer 6 is a composite electroformed metal body 20 formed of the printed pattern electroformed metal layer 10.

FIG. 2 is a schematic view of a composite electroformed metal body 21 provided with a metal coating film 11. One of the composite electroformed metal bodies 20 which takes the following method to prevent separation between the electroformed metal network layer 5 and the printed pattern electroformed metal layer 10 of the metal body 20 having an opening ratio of 40% or more. Is preferred. Film thickness 1 to 1
The metal coating film 11 of 0 μ is formed from both the printed surface and the squeegee surface by a vapor deposition method, an electroless plating method, an electroforming method, or the like to form a metal mask 30 composed of another composite electroformed metal body 21. The metal coating film 11 may be a metal such as nickel, copper or chromium. When the thickness of the metal coating film 11 is 1 μm or less, the printed pattern electroformed metal layer 10 may be separated from the electroformed metal mesh layer 5. On the other hand, when the thickness is 10 μm or more, the dimensions of the printed pattern electroformed metal layer 10 and the electroformed metal mesh layer 5 are largely changed, the aperture ratio of the electroformed metal mesh layer 5 is lowered, and printing is hindered.

In the metal mask 30 formed by forming the present metal coating film 11, as shown in Example 2, no peeling of the printed pattern electroformed metal layer 10 and electroformed metal mesh layer 5 was observed at the time of printing. . Also, no peeling was confirmed in the tape test.

Among the composite electroformed metal bodies 20, in order to prevent the electroformed metal mesh layer 5 and the printed pattern electroformed metal layer 10 of the metal body 20 having an aperture ratio of 40% or more from peeling off, the following method is used. It is preferable to take. In order to form the metal coating film 11 only from the squeegee surface, the non-conductive film having a film thickness of 10 to 50 μm is formed only from the printed surface of the composite electroformed metal body 20. This non-conductive film is a photoresist (DFR or liquid resist)
However, it may be masking tape. At this time, the conductive portion of the composite electroformed metal body 20 is secured. When a photoresist is used for the non-conductive film, the photoresist is cured by an exposure device (either parallel light or diffused light may be used) to form a non-conductive film. The metal coating film 11 having a film thickness of 1 to 10 μm is formed on the composite electroformed metal body 20 on which the non-conductive film is formed only from the squeegee surface by a vapor deposition method, an electroless plating method, an electroforming method, or the like. The metal coating film 11 may be nickel, copper, chromium or the like. After that, the non-conductive film is removed to form the metal mask 30 made of the composite electroformed metal body 21. The film thickness of the metal coating film 11 is
If the thickness is 1 μm or less, the effect of preventing separation between the printed pattern electroformed metal layer 10 and the electroformed metal mesh layer 5 may be insufficient. 1
If it is 0 μm or more, the dimensions of the printed pattern electroformed metal layer 10 are changed, and the aperture ratio of the electroformed metal mesh layer 5 is lowered, which impairs printing.

In the metal mask 30 formed by forming the present metal coating film 11, no peeling between the printed pattern electroformed metal layer 10 and the electroformed metal mesh layer 5 was observed as shown in Example 2. Further, no peeling was confirmed even when the tape test was conducted. Further, since the processing is performed from one side, the dimensional accuracy of the printed pattern electroformed metal layer 10 and the electroformed metal mesh layer 5 is extremely excellent.

[0031]

[Example] [Example 1] The conductor substrate 1 has a plate thickness of 0.2 mm.
Of SUS304 material of 160 × 160 mm2 size,
The surface of one of them was adjusted. The surface was measured with a surface roughness meter made by Kosaka Laboratory, Surfcoder SE-40C,
The average roughness was 0.3 μm. Subsequently, pretreatment such as degreasing, dilute pickling, and washing with water was performed. As shown in FIGS. 2B and 2C, the first photoresist film 2 is formed by heating the conductor substrate 1 to 60 ° C., and then FP24 manufactured by Tokyo Ohka Kogyo Co., Ltd.
It is formed by laminating DFR of 0, and the mesh width is 0.
EXM-1 manufactured by ORC using a glass mask having a diameter of 0.5 mm and a hole number of 4700 using a glass mask having a square mesh pattern of 03 mm.
UV exposure was performed with 201A-01. After aging for 15 minutes, alkaline development was performed with a vertical developing machine and washing with water was performed to form a first resist pattern 4, and the conductor substrate 1 was exposed in a mesh pattern (FIG. 2d). Next, in a high hardness nickel sulfamate plating bath, the thickness of the exposed substrate is 30 μm at 0.3 A / dm 2.
m electroformed metal mesh layer 5 was formed (Fig. 2e). On the electroformed metal mesh layer 5 and the first resist pattern 4 thus formed, acid activation was performed with 10% sulfuric acid, and a catalyst was applied with an Enplate Activator 444 manufactured by Meltex Co., Ltd., followed by Melplate PA360 manufactured by the same company. After pretreatment for adhesion enhancement, a 2 μm thick electroless nickel plating thin film 6 was formed (FIG. 2f). Next, pretreatment such as degreasing, dilute pickling, and water washing was performed on the electroless nickel-plated thin film 6. The second photoresist film 7 is formed by heating the conductive substrate 1 on which the electroformed metal mesh layer 5 and the electroless nickel thin film 6 are formed to 60 ° C. and then laminating the DFR, and using the exposure machine to UV. After exposure and aging for 15 minutes, alkaline development with a vertical developing machine and washing with water were performed to form a second resist pattern 9 to expose the electroless nickel plating thin film 6 (FIG. 2g).
~ I). A printed negative pattern electroformed metal layer 10 having a thickness of 20 μm was formed at 0.5 A / dm 2 in a high hardness nickel sulfamate plating bath to form a composite electroformed metal body 20 (FIG. 2 j). The film composite was peeled off from the conductor substrate 1 (see FIG.
k), the resist patterns 4 and 9 were removed by immersing in a commercially available alkaline stripping solution to produce a metal mask 30 composed of the composite electroformed metal body 20 (FIG. 21).

Unlike the woven mesh such as the α mesh, the metal mask 30 does not cause the positional shift between the meshes due to the tension of the cloth. Therefore, the printed pattern electroformed metal body 10 can be obtained with high positional accuracy. Further, since the breaking strength can be doubled, the aperture ratio can be doubled. Further, since the printed pattern is formed by the electroforming method, the side surface shape and dimensional accuracy are excellent.

[Embodiment 2] Of the composite electroformed metal body 20 produced in Embodiment 1, the metal body 2 having an aperture ratio of 40% or more is particularly preferable.
In order to prevent peeling between the electroformed metal mesh layer 5 having a line width of 30 μm and the printed pattern electroformed metal layer 10, the metal coating film 11 was formed. The composite electroformed metal body 20 having the printed pattern electroformed metal layer 10 on the electroformed metal mesh layer 5 is plated with a film thickness of 2 μm at 1 A / dm 2 in a high hardness nickel sulfamate bath to form a composite electroformed metal. A metal mask 30 composed of a body was created.

A diameter of 0.5 mm prepared according to this embodiment,
In the metal mask 30 for forming a print pattern having the number of holes 4700, a print test was performed on a printed matter using a solder resist ink TF-200 manufactured by Taiyo Ink Mfg. Co., Ltd. As a result, a metal coating film 11 formed an electroformed metal mesh layer. 5
The adhesion of the electroformed metal layer 10 with the printed pattern was improved, and no peeling between the electroformed metal network layer 5 and the electroformed metal layer 10 with the printed pattern was observed at the time of printing. Further, no peeling was confirmed in the tape test.

[Embodiment 3] Of the composite electroformed metal body 20 prepared in Embodiment 1, the metal body 2 having an aperture ratio of 40% or more is particularly preferable.
In order to prevent the electroformed metal mesh layer 5 having a line width of 30 μm and the printed pattern electroformed metal layer 10 from peeling, a metal coating film 11 was prepared. In order to prevent contact with the plating solution on the printed surface, the composite electroformed metal body 20 having the printed pattern electroformed metal layer 10 on the electroformed metal mesh layer 5 is pasted with the DFR only from the printed surface, and the UV exposure is performed. It was cured by a machine to form a non-conductive film. At this time, in order to secure the conductive portion, the DFR was not attached to each of the four corners of the composite conductive metal body 20 in an area of 1 cm 2. In the high hardness nickel sulfamate bath, the composite electroformed metal body 20 provided with the non-conductive film has a film thickness of 5 μ at 1 A / dm 2 only from the squeegee surface.
Plating 11 of m was applied, and the DFR was peeled off by immersing in the commercially available alkaline peeling liquid to prepare a metal mask 30 composed of the composite electroformed metal body 21.

The metal mask 30 prepared according to this embodiment
Thus, the electroformed metal mesh layer 5 and the printed pattern electroformed metal layer 1
The adhesion of No. 0 was improved, and no peeling between the printed pattern electroformed metal layer 10 and the electroformed metal mesh layer 5 was observed at the time of printing. Furthermore, no peeling was observed even after the tape test. Further, the shape of the printed pattern electroformed metal layer 10 is excellently maintained, and the electroformed metal layer 10 can be utilized even in a finer pattern.

[Effect of the Invention] According to the present invention, since the electroformed metal mesh layer 5 of the composite electroformed metal body 20 is formed of a single layer, the mechanical strength of the metal mask is high and the metal mask has a woven mesh-like shape. There is no misalignment between the meshes due to the tension. Therefore, the printed pattern electroformed metal body 10 can be obtained with high positional accuracy. Further, when compared with a printing metal mask having the same aperture ratio, the breaking strength of the metal mask 30 made of the composite electroformed metal body 20 or 21 of the present invention is 2 as compared with that produced from a mesh screen. Has twice the strength. Furthermore, when the breaking strengths are the same, the composite electroformed metal body 20 or 21 of the present invention is
It is possible to double the aperture ratio of the electroformed metal mesh layer 5 of the metal mask 30 made of, and in combination with the effect that the shape of the print pattern is smooth, excellent printability is provided.

In addition to the above effects, by forming the print pattern by electroforming, the side surface shape of the opening and dimensional accuracy are excellent, and the plate thickness can be formed without limitation. Further, by forming the metal coating film 11 on the entire metal mask, a printing pattern for the tape test or printing, the electroformed metal layer 1
No peeling from the electroformed metal mesh layer 5 of 0 could be confirmed at all. This effect was obtained even if the aperture ratio of the electroformed metal mesh layer 5 was increased.

Further, by forming the metal coating film 11 only on the electroformed metal mesh layer 5, a highly accurate metal mask can be obtained without substantially changing the size and shape of the printed pattern electroformed metal layer 10. I was able to. Further, the present invention has a simple manufacturing process, and therefore has a low cost and a good yield.

[Brief description of drawings]

1A and 1B are schematic external views (partly) of a metal mask for printing according to the present invention.

FIG. 2 is another schematic external view (partial view) of the printing metal mask of the present invention.

3 (a) (b) (c) (d) (e) (f) (g) (h) (i) (j) (k) (l) (m) The metal mask for printing of the present invention. FIG. 6 is a schematic cross-sectional view showing the manufacturing process of.

FIG. 4 is a schematic external view of a conventional printing metal mask.

[Explanation of symbols]

1 conductor board 2 First photoresist layer 3 First photomask 4 First resist pattern 5 Electroformed metal mesh layer 6 Electroless nickel layer 7 Second photoresist layer 8 Second photomask 9 Second resist pattern 10 Printing pattern Electroformed metal layer 11 Metal coating film 20 Composite electroformed metal body 21 Composite electroformed metal body (with metal coating film) 30 metal mask 40 mesh screen

[Reference number] MP010003

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[Procedure amendment]

[Submission date] March 29, 2002 (2002.3.2)
9)

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Fig. 2]

[Figure 3 (a)]

[Fig. 3 (b)]

[Fig. 3 (c)]

[Fig. 3 (d)]

[Fig. 3 (e)]

[Fig. 3 (f)]

[Figure 1]

[Fig. 3 (g)]

[Figure 3 (h)]

[Figure 3 (i)]

[Fig. 3 (j)]

[Fig. 3 (k)]

[Fig. 3 (l) (m)]

[Figure 4]

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kozue Tanaka             1-103-52 Yoshinodai, Kawagoe City, Saitama Prefecture Stock Association             Company Process Lab Micron (72) Inventor Miyuki Kitayama             1-103-52 Yoshinodai, Kawagoe City, Saitama Prefecture Stock Association             Company Process Lab Micron F-term (reference) 2H084 AA30 BB02 CC09                 2H097 BA06 CA12 LA02                 2H114 AB12 AB13 AB15 DA04 EA01                       EA02 EA04 EA08 GA01 GA11

Claims (3)

[Reference number] MP010003 [Submission date] September 3, 2001 [Claims] 1. A first resist pattern having a desired mesh shape is formed on a smooth conductor substrate by a UV lithography method to expose the conductor substrate surface in a mesh shape, and the exposed conductor substrate surface is exposed. A step of forming a metal mesh by electroforming, a metal thin film is formed on the metal mesh and the resist pattern, and then a printing pattern consisting of a second resist pattern is formed on the metal thin film by UV lithography. After that, a step of forming a composite electroformed metal body on the printing pattern by an electroforming method, and peeling the film-shaped composite body including the composite electroformed metal body and the first and second resist patterns from the conductor substrate After that, a step of removing the first and second resist patterns from the film-shaped composite body to produce the composite electroformed metal body, the printing metal mask. 2. A step of adding a metal coating film by electroforming to the composite electroformed metal body produced by removing the first and second resist patterns from the film body. The metal mask according to claim 1, which is characterized in that. 3. The metal mesh surface of the composite electroformed metal body produced by removing the first and second resist patterns from the film-shaped body is further subjected to a metal vapor deposition method, an electroless plating method, or an electroforming method. The metal mask according to claim 1, wherein a step of adding a metal coating film is added.