JP2008221754A - Manufacturing method of metal mask for screen printing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a metal mask for screen printing which can meet the requirements of an ultrafine and high definition pattern by significantly improving the followability in case a second dry film resist is formed on a first metallic film through the procedure to positively remove a first dry film resist after the first metallic film is formed by plating using the first dry film resist. <P>SOLUTION: This manufacturing method comprises a process to form the first dry film resist in a position which becomes a mesh opening of a mesh part to give a print pattern on a substrate, a process to form the first metallic film 5 by plating on the surface of a part, where the first dry film resist is not formed, of the substrate, a process to remove the first dry film resist, and a process to apply the second dry film 6 as a light-sensitive material, with successful followability, to the surface of the first metallic film 5. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a metal mask for screen printing used for printing cream solder, conductive paste or the like.

  2. Description of the Related Art Conventionally, screen printing that enables high-precision pattern printing has been adopted when solder paste (cream solder), conductor paste, or the like is applied and formed on a printed wiring board for mounting various electronic components. In particular, when high-precision pattern printing is desired, a screen printing plate such as a metal mask is used as a plate material for screen printing.

  In screen printing using a metal mask, a squeegee or a press is applied from one surface (squeegee surface) to the other surface (surface on the substrate side) of the metal mask that is in contact with or slightly away from the surface of the substrate. Printing is performed on the surface of the printing material by extruding printing ink and other adhering materials from the pattern-shaped holes provided in the metal mask while being pressed against the surface of the printing material with pressure or the like. This printing method is suitable when the substrate is a flat plate.

  In recent years, with the miniaturization of electronic equipment or electronic components, the hole pattern provided in the metal mask for applying and forming solder paste on the printed wiring board is extremely fine and the distance between the holes (hole pitch) is small. It is becoming very short. In order to form a high-definition pattern, it is advantageous to basically make contact between the metal mask and the substrate.

  In this way, a metal mask in which extremely fine holes are densely packed is in contact with the printed material during printing, and the viscosity and surface tension of the solder paste and flux, and further, the printed surface of the printed material and the printed surface of the printed material. Due to the adhesive force due to the pressing of the sheet, it is in close contact with the substrate, and the separation of the plate is likely to deteriorate. If the two sides are forcibly peeled off in the state where the plate separation has deteriorated, the solder paste in the pattern-like holes will not come off to the printed material, and the solder paste will adhere to the inner walls of the holes, and the printed pattern It will cause the shape to collapse. In addition, the solder paste is scattered on the substrate to be printed, which may cause stains on the printed surface and bleeding of edges in the printed pattern shape.

To date, many discussions have been made on improving the performance of metal masks, and various improvements have been made.
For example, a printed wiring board manufacturing method in which a metal mask having a pattern formed on a surface of a printed wiring board substrate is adhered, and a vapor deposition material is deposited on the surface of the substrate by a vapor phase method to form a circuit. The first photoresist layer is formed on the base film, the first photoresist layer is differentiated and exposed through the first pattern mask, and then developed to form the first resist layer having a pattern. Forming a first plating layer on the portion of the base film from which the photoresist layer has been removed by the development, forming a second photoresist layer on the first photoresist layer and the first plating layer Then, after the second photoresist layer is differentiated and exposed through the second pattern mask, the second photoresist layer is developed, and the first resist layer and the first resist layer A second resist layer having a pattern is formed on the plating layer, and the second pattern mask is connected to the first plating layer so that the first plating layer can be fixed according to the pattern. The mesh pattern is formed on all or part of the first resist layer in the form, or the first plating layer is a plating layer having a mesh on all or part, and the second pattern mask is The second pattern is formed so that it can be fixed according to the pattern in connection with the mesh of the first plating layer, and the development of the second photoresist layer is substantially the same as the first resist layer. A step of performing under conditions that are not removed, a step of forming a second plating layer on the first resist layer and the first plating layer, where the second photoresist layer is removed by development, and remaining The first and second resist layer and manufacturing method of the printed wiring board is a metal mask having a mesh moiety obtained by removing the base film is known that. And this is obtained by a two-stage additive method. In this two-stage additive method, a circuit part is formed by the first plating, and a mesh is formed by the second plating (post-mesh forming method); Conversely, it is known that there is a method (former mesh formation method) in which a mesh is formed by the first plating and a circuit portion is formed by the second plating (for example, refer to Patent Document 1).

  Also, a first step of forming a photosensitive resin layer having a predetermined thickness on the substrate and a film on which a pattern is formed on the photosensitive resin layer so that light is transmitted through a necessary opening of the metal mask are overlapped. A second step of exposing, a third step of developing and removing only the non-exposed portion of the photosensitive resin layer to expose the substrate, and a metal mask material layer by plating on the exposed portion of the substrate obtained in the third step After performing the fourth step of forming, the fifth step of forming the resin film layer in the range excluding the portion to be thickened on the surface of the metal mask material layer that finished the fourth step, and the fifth step A metal mask layer having a necessary cross-sectional shape is formed by repeating the sixth step of forming a metal mask material layer by plating and increasing the thickness once or a necessary number of times on the exposed metal mask material layer. And then exposure to the rest A screen printing metal mask manufacturing method is known in which a metal mask is manufactured by performing a seventh step of removing the photosensitive resin layer and an eighth step of separating the laminated metal mask material layer from the substrate. (For example, refer to Patent Document 2).

  Furthermore, a step of preparing a base material, a step of forming a first resist on the base material at a position to be a mesh opening of a mesh portion that gives a print pattern, and a first resist on the base material Forming a first metal film by plating, forming a second resist with a reversal pattern of the print pattern on the first resist and the first metal film, Forming a second metal film by plating on the first metal film, excluding a region where the second resist is formed, removing the first and second resists, There is known a method for producing a screen printing plate including each step of integrally peeling the second metal film (see, for example, Patent Document 3).

Japanese Patent Laid-Open No. 3-228052 JP-A-4-166844 JP-A-5-85077

  In the conventional method for producing a metal mask for screen printing by the two-step plating method, when the dry film resist is used as the photoresist layer, the second dry film resist is used in the situation where the first dry film resist remains. When the first dry film resist is formed, if the space distance between the resists is narrow and small when the first dry film resist is formed, the second dry film resist hardly follows the upper surface of the first dry film resist and overlaps in a relaxed state. There is a problem that it ends up. The second dry film resist follows the first dry film resist especially in the recent trend in which a very fine pattern with a very fine distance (hole pitch) between mesh patterns is required. The fact that it is difficult to carry out and overlaps in a relaxed state has been a big problem because the yield of the product has deteriorated.

  The present invention has been made to solve the above-described problems. Even when a two-step plating method is used and a dry film resist is used as a photoresist layer, the first dry film resist is used. After the first metal film plating is formed by using the step, the followability when the second dry film resist is formed on the first metal film by positively removing the first dry film resist. Is significantly improved to provide a method for producing a metal mask for screen printing that can meet the demands for extremely fine and high-definition patterns.

In the manufacturing method of the metal mask for screen printing concerning this invention, the process of apply | coating the 1st dry film as a photosensitive agent on a board | substrate, and the mesh part and the plate-film part were provided on the 1st dry film. A step of exposing a print pattern, a step of forming a first dry film resist at a position to be a mesh opening of a mesh portion that gives a print pattern on a substrate, and a first dry film resist of a base material is formed A step of forming a first metal film on the surface of the unexposed portion by plating, a step of removing the first dry film resist, and a second dry film as a photosensitive agent on the first metal film with good followability A step of applying, a step of exposing a reverse pattern of the print pattern on the second dry film, and a reverse pattern of the print pattern on the first metal film. And forming a second dry film resist on the surface of the first metal film where the second dry film resist is not formed by plating, 2, a process of removing the dry film resist, and a process of integrally peeling the first metal film and the second metal film from the substrate.
In addition to the above description, the step of forming the dry film resist may be a direct drawing method using ultraviolet light, semiconductor laser light, or the like.

In the method for manufacturing a screen printing metal mask according to the present invention, a step of applying a first dry film as a photosensitive agent on a substrate, and a mesh portion and a plate film portion on the first dry film. A step of exposing the printed pattern provided, and a step of forming a first dry film resist higher than the first metal film formed in a subsequent step at a position to be a mesh opening of a mesh portion that gives a printed pattern on the substrate And forming a first metal film on the surface of the portion of the substrate where the first dry film resist is not formed by plating so as to be lower than the upper surface of the first dry film resist; A step of removing the dry film resist, a step of applying a second dry film as a photosensitive agent on the first metal film with good followability, and a second dry film A step of exposing a reversal pattern of the print pattern on the film, a step of forming a second dry film resist having a reversal pattern of the print pattern on the first metal film, and a second step on the first metal film. Forming a second metal film on the surface of the portion where the dry film resist is not formed by plating, removing the second dry film resist, and the first metal film and the second metal film from the substrate. And a step of integrally peeling the metal film.
In addition to the above description, the step of forming the dry film resist may be a direct drawing method using ultraviolet light, semiconductor laser light, or the like.

  According to the present invention, the first metal film plating is formed using the first dry film resist even when the two-step plating method is employed and the dry film resist is used as the photoresist layer. Thereafter, by actively removing the first dry film resist, it is possible to remarkably improve the followability when the second dry film resist is formed on the first metal film. There is an effect that it is possible to obtain a metal mask that can meet the demand for high-definition patterns.

Embodiment 1 FIG.
FIGS. 1-11 is sectional drawing which shows each process of the manufacturing method of the metal mask for screen printing in Embodiment 1 of this invention in order.
In the method for producing a metal mask for screen printing according to the present invention, first, a first dry film 2 is applied as a first photosensitive agent on a substrate (SUS or the like) 1 (see FIG. 1). Next, on the first dry film 2, a screen printing plate 3 showing a printing pattern including a mesh portion 3a and a plate film portion 3b is arranged, and mesh pattern exposure is performed (see FIG. 2). A first dry film resist 4 is formed at a position to be a mesh opening of a mesh portion that gives a printed pattern on the substrate 1 (see FIG. 3). Then, a first metal film 5 is formed by plating on the surface of the portion of the substrate 1 where the first dry film resist 4 is not formed (see FIG. 4). Although the height of the surface of the first metal film 5 formed by plating and the height of the upper surface of the first dry resist 4 are strictly controlled to be the same, actually, as shown in FIG. The upper surface of the first dry film resist 4 is slightly higher. Therefore, a step of removing all of the first dry film resist 4 is newly added as the next step (see FIG. 5). The step of forming the dry film resist may be a direct drawing method using ultraviolet rays, semiconductor laser light, or the like other than the above description.

  A feature of the present invention is that a step of removing all of the first dry film resist 4 is added. By adding this step, the surface of the first metal film 5 on the substrate 1 is entirely flat because the first dry film resist 4 does not exist at all (FIG. 5). The followability when applying the second dry film 6 as the second photosensitive agent on the first metal film 5 is extremely improved, and the second dry film 6 is applied to the surface of the first metal film 5 without slack. (See FIG. 6). Next, a screen printing plate 7 showing a reversal pattern of the print pattern is placed on the second dry film 6, and print pattern exposure is performed (see FIG. 7) to print on the first metal film 5. A second dry film resist 8 is formed with a pattern reversal pattern (see FIG. 8). Then, a second metal film 9 is formed by plating on the surface of the portion where the second dry film resist 8 is not formed on the first metal film 5 (see FIG. 9). Next, the second dry film resist 8 is removed (see FIG. 10). Finally, the first metal film 5 and the second metal film 9 are integrally peeled off from the substrate 1 to obtain a screen printing metal mask (see FIG. 11).

Comparative example.
FIG. 12 is a sectional view showing a part of a conventional method for producing a metal mask for screen printing, and corresponds to FIG. 6 in the present invention.
In the conventional method for producing a metal mask for screen printing, the height of the surface of the first metal film 5 formed by plating and the height of the upper surface of the first dry film resist 4 are strictly controlled so as to be the same. However, as described above, the upper surface of the first dry film resist 4 is actually slightly higher. Therefore, conventionally, the protruding upper surface of the first dry film resist 4 is in the way, so that the followability when the second dry film 6 is applied on the first metal film 5 is deteriorated, as shown in FIG. As described above, the second dry film 6 is applied in a loose state, and there is a problem that the yield of the product is deteriorated.

  However, according to the present invention, it is possible to remarkably improve the followability when the second dry film resist is formed on the first metal film by adopting the two-step plating method. A metal mask that can meet the demands of various patterns can be obtained.

It is sectional drawing which shows the first process of the manufacturing method of the metal mask for screen printing in Embodiment 1 of this invention. It is sectional drawing which shows the next process of the manufacturing method of the metal mask for screen printing in Embodiment 1 of this invention. It is sectional drawing which shows the next process of the manufacturing method of the metal mask for screen printing in Embodiment 1 of this invention. It is sectional drawing which shows the next process of the manufacturing method of the metal mask for screen printing in Embodiment 1 of this invention. It is sectional drawing which shows the next process of the manufacturing method of the metal mask for screen printing in Embodiment 1 of this invention. It is sectional drawing which shows the next process of the manufacturing method of the metal mask for screen printing in Embodiment 1 of this invention. It is sectional drawing which shows the next process of the manufacturing method of the metal mask for screen printing in Embodiment 1 of this invention. It is sectional drawing which shows the next process of the manufacturing method of the metal mask for screen printing in Embodiment 1 of this invention. It is sectional drawing which shows the next process of the manufacturing method of the metal mask for screen printing in Embodiment 1 of this invention. It is sectional drawing which shows the next process of the manufacturing method of the metal mask for screen printing in Embodiment 1 of this invention. It is sectional drawing which shows the last process of the manufacturing method of the metal mask for screen printing in Embodiment 1 of this invention. It is sectional drawing which shows 1 process of the manufacturing method of the conventional metal mask for screen printing.

Explanation of symbols

1 Substrate 2 First dry film (photosensitive agent)
3 Screen printing plate 3a Mesh portion 3b Plate film portion 4 First dry film resist 5 First metal film 6 Second dry film (photosensitive agent)
7 Screen printing plate 8 Second dry film resist 9 Second metal film

Claims (2)

Applying a first dry film as a photosensitive agent on a substrate;
A step of exposing a printed pattern comprising a mesh portion and a plate portion on the first dry film;
Forming a first dry film resist at a position to be a mesh opening of a mesh portion that gives a printed pattern on the substrate;
Forming a first metal film on a surface of a portion of the base material where the first dry film resist is not formed by plating;
Removing the first dry film resist;
Applying the second dry film as a photosensitive agent on the first metal film with good followability;
Exposing the reversal pattern of the print pattern on the second dry film;
Forming a second dry film resist on the first metal film with a reverse pattern of a print pattern;
Forming a second metal film by plating on the surface of the portion where the second dry film resist is not formed on the first metal film; and
Removing the second dry film resist;
Integrally peeling the first metal film and the second metal film from the substrate;
A method for producing a metal mask for screen printing, comprising: Applying a first dry film as a photosensitive agent on a substrate;
A step of exposing a printed pattern comprising a mesh portion and a plate portion on the first dry film;
A step of forming a first dry film resist higher than a first metal film formed in a subsequent step at a position to be a mesh opening of a mesh portion that gives a printed pattern on the substrate;
Forming a first metal film on a surface of a portion of the base material where the first dry film resist is not formed by plating so as to be lower than an upper surface of the first dry film resist;
Removing the first dry film resist;
Applying the second dry film as a photosensitive agent on the first metal film with good followability;
Exposing the reversal pattern of the print pattern on the second dry film;
Forming a second dry film resist on the first metal film with a reverse pattern of a print pattern;
Forming a second metal film by plating on the surface of the portion where the second dry film resist is not formed on the first metal film; and
Removing the second dry film resist;
Integrally peeling the first metal film and the second metal film from the substrate;
A method for producing a metal mask for screen printing, comprising:

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