JP6736092B2 - Screen mask mesh, screen mask, and method for producing printed matter - Google Patents

Description

Embodiments of the present invention relate to a screen mask mesh, a screen mask, and a method for manufacturing a printed matter.

The screen printing method, which is one of the printing methods, uses a screen mask having a mask film formed of a resin composition on a mesh knitted with a wire rod, and an arbitrary pattern corresponding to the opening pattern formed in the mask film is used. This is a method of forming a printed matter by applying a coating material to an object. The screen printing method is used for various printings such as wiring, electrodes, and fluorescent material printing, and is used in various fields including electronic parts. For example, the mesh is knitted by arranging a plurality of wire rods vertically and horizontally. Generally, the wire rods forming the mesh are arranged so that the intervals are uniform.

JP, 2013-169783, A

In such a screen mask, it is required to stably hold the mask film on the mesh.

A screen mask mesh according to an aspect of the present invention includes a plurality of wire rods containing a tungsten compound arranged therein, has a hole through which a coating material can pass, and has a variation in an opening, which is an interval between the wire rods, which is 5 % Or more and 40% or less.

According to the embodiments of the present invention, it is possible to provide a screen mask mesh, a screen mask, and a method for manufacturing a printed material, which can secure the adhesive strength between the mask film and the mesh.

FIG. 3 is a plan view showing the configuration of the screen printing apparatus according to the first embodiment. Sectional drawing of the screen printing apparatus. The top view which shows the structure of the mesh of the same screen mask. Explanatory drawing which shows the manufacturing method of the screen mask concerning the embodiment. Explanatory drawing which shows the variation of the opening of the mesh of the same screen mask, and the adhesive strength. Explanatory drawing which shows the variation of the opening of the mesh of the same screen mask, adhesive strength, discharge amount variation, and tensile strength.

[First Embodiment]
Hereinafter, the screen printing apparatus 10 and the screen mask 20 according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 is a plan view of the screen printing device 10 according to the present embodiment as seen from the Z direction, and FIG. 2 is a sectional view as seen from the X direction. FIG. 3 is a plan view showing the structure of the mesh. FIG. 4 is an explanatory view showing the method of manufacturing the screen mask 20, and shows the configuration of the cross section of the screen mask 20. FIG. 5 is an explanatory diagram showing the relationship between the variation in the openings of the screen mask 20 according to this embodiment and the adhesive strength. FIG. 6 is an explanatory diagram showing the relationship among the variation in the opening of the screen mask 20 according to the present embodiment, the adhesive strength, the variation in the ejection amount, and the tensile strength. It should be noted that, in each drawing, for convenience of explanation, the configuration is illustrated by enlarging, reducing, or omitting. Arrows X, Y, and Z in the drawing respectively indicate three directions orthogonal to each other, the first direction is the Y direction, and the second direction is the X direction.

As shown in FIG. 1, the screen printing apparatus 10 includes a screen mask 20, a holding member 12 that holds a print medium 30 so as to face one surface (front surface) of the screen mask 20, which is the printing surface side, and the screen mask. The squeegee 13 configured to be movable while being in contact with the other surface (back surface) opposite to the printing surface side of 20, the moving means for moving the squeegee 13, and the screen mask 20 facing the print medium 30. And a supporting means for supporting.

The screen printing device 10 forms various printing materials on the surface of the printing medium 30 in a predetermined pattern. The screen printing device 10 is, for example, for a chip component (capacitor, chip resistor, inductor, thermistor, etc.), touch panel, liquid crystal display (LCD) seal, LTCC (Low Temperature Co-fired ceramics) substrate, solar cell Used for manufacturing electrodes and other electronic parts.

The screen mask 20 includes a frame 21, a mesh portion 22 (screen mask mesh) stretched over the frame 21, and a mask film 23 formed on the mesh portion 22. In the screen mask 20, the side facing the surface of the print medium 30 when printing is performed is the front surface, and the opposite side to which the coating material is supplied is the back surface.

The frame 21 has two pairs of sides that are parallel to each other, and is configured in a frame shape having, for example, a rectangular opening of a desired size. The frame 21 supports the outer peripheral edge of the mesh portion 22 and stretches the mesh portion 22 in the opening. In the present embodiment, as an example, the size of the opening of the frame 21 in the Y direction is 275 mm and the size in the X direction is 275 mm.

The frame 21 also functions as a frame for holding a predetermined amount of coating material on the back surface side of the mask film 23. The frame 21 and the mesh portion 22 are joined to each other at a joining portion by using, for example, a synthetic rubber adhesive or a cyanoacrylate adhesive.

The mesh portion 22 is a so-called combination type in which the inner main mesh 26 and the outer support mesh 27 having different elongations are fixed and connected to each other at the joint portion 22a with a UV curable adhesive. The mesh portion 22 holds the mask film 23 in the opening portion of the frame 21.

The main mesh 26 has a square shape or a rectangular shape. In the present embodiment, as an example, the main mesh 26 is a rectangle having a dimension in the Y direction of 220 mm and a dimension in the X direction of 200 mm.

The main mesh 26 is a woven fabric formed by knitting warp yarns 26a and weft yarns 26b, which are wire rods, and the wire rods are arranged in a plurality of rows and have a large number of hole portions 26c which are transmissive portions that open the coating material. Have The warp yarns 26a and the weft yarns 26b of the main mesh 26 are made of, for example, a metal wire containing a tungsten compound. The warp yarn 26a and the weft yarn 26b respectively extend obliquely with respect to the moving direction of the squeegee 13 along the arrow in FIG. 1, for example.

In the main mesh 26, the warp yarns 26a and the weft yarns 26b have a diameter of wire diameter=φ13 μm, and the arrangement density is 430 yarns/inch.

The variation in the mesh size, which is the interval at which the weft yarns 26b of the main mesh 26 are arranged, is 5% or more and 40% or less, and preferably 10% or more and 30% or less.

In the present embodiment, in the main mesh 26, a plurality of weft yarns 26b are passed in a direction intersecting the warp yarns 26a while the warp yarns 26a are arranged at a predetermined pitch, and the weft yarns 26b alternate between one and the other of the warp yarns 26a. It is organized to pass. Therefore, the weft yarn 26b has a wavy shape, and the warp yarn 26a extends straighter than the weft yarn 26b. In the present embodiment, the variation in the interval between the weft yarns 26b having the wavy shape is the variation in the opening.

Here, the opening is the width of the hole portion 26c which is a transmission part which is a space of the space between the wire rods, and the opening standard is expressed by the following formula. For opening measurement, a CNC image measuring system VMR-6555 manufactured by Nikon Corporation is used. In the present embodiment, the distance between the weft yarns 26b, which are wavy wire rods, is measured at 100 places, and the deviation from the standard value is expressed in %.
Opening standard [mm]=25.4/number of meshes [inch]-wire diameter [mm]
…(Equation 1)
The warp yarns 26a and the weft yarns 26b that form the main mesh 26 have a surface roughness (Ra) larger than 0.1 [μm]. The surface roughness Ra is an average obtained by measuring 5 μm line roughness in 5 directions in a direction orthogonal to the wire material using a laser microscope VK-8710 manufactured by Keyence Corporation.

The support mesh 27 is joined to the outer periphery of the main mesh 26 with an adhesive. The support mesh 27 is a woven fabric formed by knitting warp yarns 27a and weft yarns 27b, and is configured by arranging wire rods in a plurality of rows. The support mesh 27 has a lower elongation rate than the main mesh 26. The warp yarns 27a and the weft yarns 27b of the support mesh 27 are made of, for example, metal wires such as stainless steel.

The outer shape of the support mesh 27 is a shape corresponding to the shape of the opening portion 21a of the frame 21, and is configured in a square shape having the same dimension in the X direction and that in the Y direction. The outer periphery of the support mesh 27 is joined to and supported by the frame 21 with an adhesive or the like.

The mask film 23 is a layer made of a photocurable resin composition such as PVA, PVAc, silicon resin, acrylic resin, or epoxy resin. The mask film 23 is formed on the mesh portion 22 and arranged in the opening portion of the frame 21. A predetermined opening pattern 23a for printing is formed on the mask film 23 by maskless exposure. The opening pattern 23a is formed in the main mesh 26 portion. The opening pattern 23a has a plurality of module patterns 23b. That is, in the effective area A3 of the mask film 23, the same module pattern 23b is arranged in a matrix with a plurality of rows, for example, 30 rows and 40 rows, in the vertical direction and the horizontal direction, respectively. For example, each module pattern 23b is a line pattern. In the present embodiment, the effective area A3 in which the pattern is formed is defined inside the outer edge of the main mesh 26, and the opening pattern 23a is formed inside the effective area A3.

The mask film 23 constitutes a printing section in which the photosensitive resin does not exist in the opening pattern 23a and the coating material can pass through the holes of the mesh section 22 to pass from the back surface to the front surface. The area other than the opening pattern 23a of the mask film 23 and the area where the holes of the mesh portion 22 are blocked with the photosensitive resin constitutes a non-printing portion that does not allow ink as a coating material to pass therethrough.

The mesh portion 22 on which the mask film 23 is formed is configured to be elastically deformable so as to be flexibly deformed by the pressing force of the squeegee 13 and to be restored when the pressing force is released. When the coating material is held in the opening pattern 23a of the mask film 23, the mask film 23 is brought into contact with or separated from the print medium 30 by the elastic deformation of the mesh portion 22, so that the coating material is transferred from the opening pattern 23a to the print medium 30. To be done.

The squeegee 13 is made of, for example, urethane rubber, silicon rubber, synthetic rubber, metal, plastic, or the like, and has a thin plate shape. For example, the squeegee 13 is chamfered so that the thickness of the tip is reduced. The squeegee 13 is configured to be capable of reciprocating with respect to the frame 21. For example, the squeegee 13 is configured to have a length over the entire area of the mask film 23 in the direction orthogonal to the moving direction. With the tip of the squeegee 13 in contact with the back surface of the screen mask 20 and being pressed to the front side, the squeegee 13 moves in the moving direction along the Y direction to press the entire surface of the mask film 23 and pre-fill with the coating material. The coating material is extruded from the open pattern 23a to the front side.

The supporting means supports the frame 21 in parallel with the print medium 30 with a predetermined gap G1 therebetween. The moving means moves the squeegee 13 at a predetermined speed in the first direction.

Next, a method for manufacturing a printed matter by the screen printing method using the screen printing apparatus 10 according to the present embodiment will be described with reference to FIGS. 1 to 3. First, the surface side of the screen mask 20 is arranged so as to face the surface of the print medium 30 held by the holding member 12.

Then, a high-viscosity paste-like coating material is supplied from the back surface side of the screen mask 20, that is, the surface opposite to the print medium 30, and the coating material is filled in the opening pattern 23a.

Next, the squeegee 13 is arranged on the back surface of the screen mask 20, that is, the surface opposite to the printing surface side. At this time, for example, the squeegee 13 is arranged at a predetermined angle with respect to the front surface of the print medium 30. Then, the squeegee 13 is moved at a predetermined speed along the Y direction while pressing the squeegee 13 toward the print medium 30 side with a predetermined printing pressure on the back surfaces of the mesh portion 22 and the mask film 23.

The squeegee 13 presses the mask film 23, for example, in a region over the entire back surface of the mask film 23. When the squeegee 13 is pressed, the mask film 23 is deformed so that the pressed portion is displaced to the front side, and contacts the print medium 30. The coating material that has passed through the squeegee 13 is extruded toward the print medium 30 from the opening pattern 23a.

After the squeegee 13 has passed, the mask film 23 and the mesh portion 22 are deformed so as to be restored and separated from the print medium 30, and a part of the coating material is transferred and remains on the print medium 30. The pattern is printed on the top to complete the printed matter. Here, a plurality of the same module patterns 23b are simultaneously drawn as the opening patterns 23a, and the printed matter is cut and divided after printing, whereby a plurality of printed matter having the same module pattern 23b is manufactured. Note that the coating material is various materials including, for example, a metal material and a resin material, and various materials are used depending on the type of print target, such as an electronic component and a display.

During printing, the squeegee 13 which is long in the X direction is moved in the Y direction by a predetermined amount while being pressed in the Z direction. The mesh portion 22 is deformed and stretched by this movement and pressing.

Next, a method of manufacturing the screen mask 20 according to this embodiment will be described. FIG. 4 is an explanatory diagram showing a method of manufacturing the screen mask 20.

The emulsion Pm serving as a mask material is a photocurable resin, and is a liquid containing, for example, polyvinyl alcohol (PVA), polyvinyl acetate (PVAc), silicon resin, acrylic resin, epoxy resin, or the like.

First, the mesh portion 22 is attached to the inside of the frame 21 so as to be substantially flat. In this state, a coating process of coating the emulsion Pm on the mesh portion 22 is performed. In the coating process, the surface of the mesh portion 22 is coated with the supply bucket containing the emulsion Pm in a state where the mesh portion 22 is installed in a substantially vertical direction (ST1).

At this time, the bucket arranged at a predetermined position is moved from the lower side to the upper side, and the emulsion Pm is applied while being leveled at the edge of the bucket, whereby the emulsion Pm is formed in a flat plate shape on the mesh portion 22. To be done. At this time, since the thickness changes depending on the number of times of coating, the coating is repeated a plurality of times as necessary. Further, the film thickness may be measured after drying and additional coating may be performed depending on the case. In the present embodiment, the thickness of the emulsion Pm is set so that the milk thickness will be about 10 μm after drying.

Next, as shown in ST2, an exposure process is performed by using a photomask mask 25 on which a mask pattern corresponding to a predetermined pattern is formed or by maskless exposure without using a mask. Specifically, in a predetermined exposure pattern area, the surface side of the emulsion Pm is arranged so as to face an irradiation head 28 such as an ultraviolet lamp or an ultraviolet LED, and light is irradiated by the irradiation head 28 to illuminate the surface of the emulsion Pm. Processing is performed (ST3).

By the exposure processing, the portion of the emulsion Pm irradiated with the ultraviolet rays is cured by the ultraviolet rays, corresponding to the portion of the exposure pattern area.

After the exposure process, the surface side of the emulsion Pm is washed away with water or a solvent as an etching process. By this treatment, as shown in ST4, the uncured portion of the emulsion Pm is washed away. That is, in the layer of the emulsion Pm, all the uncured regions are washed away, and the opening pattern 23a penetrating from the front surface side to the back surface side in the thickness direction is formed. As described above, the mask film 23 having the opening pattern 23a having a predetermined shape is formed from the emulsion Pm.

According to the mesh portion 22 and the screen mask 20 configured as described above, the adhesiveness of the emulsion can be enhanced and the mask film 23 can be retained by setting the variation in the mesh opening of the mesh portion 22 to 5% or more. It is possible to improve the property.

FIG. 5 is a graph showing the relationship between the variation in opening and the adhesive strength (peel strength) in the screen mask 20 according to the present embodiment.

In FIG. 5, the peel strength is the adhesive strength [N/cm] in a 180° peel strength test in accordance with JIS K6854 for a plurality of samples with opening variations of 5%, 10%, 20%, 30% and 40%. Are shown respectively.

According to FIG. 5, it can be seen that the peel strength is improved as the variation in the openings is larger.

That is, when a compound of tungsten is used as the wire material forming the mesh portion 22, the larger the variation in the openings, the larger the amplitude of the wavy curve of the weft thread 26b, and the easier it is to hold the emulsion. To be

Further, in the above-described embodiment, the variation in the discharge amount can be suppressed by setting the variation in the opening within 40%. FIG. 6 is a graph showing the relationship between the variation in the openings of the screen mask 20, the adhesive strength (peel strength), the variation in ejection, and the tensile strength.

From FIG. 6, it can be seen that the larger the variation in the openings, the greater the variation in the discharge amount, and the weaker the tensile strength of the mesh. That is, the larger the variation of the openings is, the larger the amplitude of the wavy curve of the weft yarn 26b is, the larger the variation of the discharge amount is, and the more uneven the arrangement of the wire material as the mesh portion 22, the easier the deformation. Therefore, in the present embodiment, it is possible to secure the accuracy of the discharge amount and the tensile strength by suppressing the variation of the openings to 40% or less.

Further, according to the present embodiment, by setting the surface roughness (Ra) of the warp yarns 26a and the weft yarns 26b as the wire material to 0.1 or more, the resistance when the squeegee moves during printing can be suppressed to be low. ..

Further, since the surface roughness of the screen mask 20 is set to 0.1 or more, the reflectance of the mesh portion 22 is lowered, so that halation during exposure can be suppressed.

It should be noted that the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements within a range not departing from the gist of the invention in an implementation stage.

In the above embodiment, a so-called combination type mesh is illustrated, but the mesh is not limited to this. For example, the mesh may be composed of only one type of main mesh.

In addition, each constituent element illustrated in the above embodiment may be deleted, and the shape, structure, material, etc. of each constituent element may be changed. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments.

DESCRIPTION OF SYMBOLS 10... Screen printing device, 12... Holding member, 13... Squeegee, 20... Screen mask, 21... Frame, 21a... Opening part, 22... Mesh part (screen mask mesh), 22a... Joining part, 23... Mask film, 23a... Opening pattern, 23b... Module pattern, 25... Photomask mask, 26... Main mesh, 26a... Warp, 26b... Weft, 26c... Hole, 27... Support mesh, 27a... Warp, 27b... Weft, 28... Irradiation Head, 30... Print medium, A3... Effective area, G1... Interval.

Claims (4)

For a screen mask, in which wire rods containing a tungsten compound are arranged in a plurality of rows, have holes through which a coating material can pass, and the variation in the openings, which is the spacing of the wire rods, is 5% or more and 40% or less. mesh. The screen mask mesh according to claim 1, wherein the surface roughness (Ra) of the wire is larger than 0.1 [μm]. A screen mask mesh according to claim 1 or 2,
And a mask film provided on the screen mask mesh and having an opening pattern. The coating material is held on the mask film of the screen mask according to claim 3, and the coating material is applied from the opening pattern of the mask film to a print medium arranged to face the print surface side of the mask film. A method for producing a printed matter, comprising: