JPH08238743A - Manufacture of plastic mask for printing, paste printing method using the mask and this mask for printing - Google Patents

Abstract

PURPOSE: To provide a method for manufacturing a plastic mask for printing to print a fine pattern of high quality level with excellent filling of paste in a patternlike through hole and excellent paste removal from a through hole, a method for printing the paste and the mask for printing. CONSTITUTION: A polymer film 11 for absorbing at least part of an excimer laser beam 2 is brought into close contact with the opposite surface 1b to the beam emitting surface of a plastic plate 1, and the beam 2 is emitted from the beam emitting surface. Then, after a patternlike through hole is formed at the plate 1, the film 11 is removed. Thus, the thin film residue or edge cracking can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a printing plastic mask, a paste printing method using the mask, and a printing plastic mask. More specifically, the present invention relates to a printing plastic mask utilizing excimer laser processing. The present invention relates to a method, a paste printing method using a plastic mask for printing obtained by the manufacturing method, and a plastic mask for printing.

[0002]

2. Description of the Related Art The following method is generally used to form a fine pattern of ink, adhesive, cream solder, paste-like resin, etc. (hereinafter referred to as paste) on a substrate using a printing mask. There is. That is, in this method, first, a printing mask in which a pattern of through-openings is formed is brought into close contact with the material to be printed, and the paste is rubbed with a squeegee on the surface of the printing mask to spread the paste to form a pattern. The paste is removed from the patterned through-opening onto the printing object by filling the through-opening with a pattern and removing the excess paste from the mask surface, and then removing the printing mask from the printing object. A pattern of paste corresponding to the copy is formed on the printing medium.

As a printing mask, when roughly classified, two types, a screen mask and a metal mask, have been put into practical use. As this metal mask, for example, a punch press mask, a YAG laser mask, an etching mask, an additive mask, and a half etching mask are known.

The punch press mask was developed as a cream solder printing mask for mounting electronic parts, and is a printing mask in which a round through hole is punched in a metal plate.

This printing mask can be easily manufactured by using NC data of the mounter in the mounting process as the processing data, and the drilling speed is high and the manufacturing time can be shortened. Although the manufacturing method is simple and the mask for printing can be manufactured at a very low cost, the manufacturing device is cheap and small, and it can be easily introduced to the printing site, on the other hand, the sagging of the opening edge of the through hole (upper end of the opening) Roundness), and a rough fracture surface and burrs are formed at the lower end of the opening, resulting in a shape of the opening in which the paste does not easily come off, resulting in the worst print quality. The minimum diameter of the through hole that can be processed is 0.
With a thickness of about 3 mm, for example, in solder paste printing for mounting electronic components, it can handle only up to about 0.5 mm pitch of QFP.

The YAG laser mask is a mask for printing in which a metal plate (usually SUS is often used) is heated and melted by a YAG laser, and the melted portion is blown off by an assist gas to open a through hole.

[0007] Since the boring process is performed based on NC data and the like, there are advantages that there is little variation due to manual work and the manufacturing time is short, but on the other hand, the inner wall surface of the opening is rough and the edge portion (edge) of the opening is There is a drawback that the print quality is rather poor due to the adherence of drows. In addition, because the convex portion of the edge portion due to the adhesion of the drows is likely to cause incomplete contact between the printing mask and the printing object during printing, in this case, the surface of the printing mask is polished to form the convex portion of the edge portion. Need to be removed.

The etching mask is formed by applying a photosensitive resin on both sides of a metal plate to form a resist layer, exposing through a photomask having a pattern of the opening, and then developing the resist layer to form the opening. The resist layer in the portion corresponding to the pattern is removed, and the resist layer is etched to form through holes in the metal plate according to the pattern to form a printing mask.

The most common method of manufacturing a metal mask,
The time required for making is shorter than that of the following additive mask, and while a printing mask can be produced at low cost, by etching from both the front and back sides, a convex shape is formed in the center of the inner wall of the opening, which deteriorates the paste removal property. However, since the inner wall surface of the opening is also rough, there is a drawback that the printing quality is poor. Further, there is a drawback that the quality of the manufactured printing mask is not stable because it requires a skilled work such as correction of optical distortion of the photomask and adjustment of etching conditions, and automation is difficult.

The additive mask is formed by forming a slightly thick photosensitive resin (dry film) layer on a plating base material, exposing it through a photomask having an opening pattern, and then developing the photosensitive resin layer. Thus, the photosensitive resin layer other than the portion corresponding to the opening pattern is removed, and only the portion corresponding to the opening pattern is left to obtain a female mold. A metal thin plate is formed by plating (mainly nickel) on the surface around the female mold of the photosensitive resin layer remaining as the opening pattern to a thickness required as a printing mask. By removing the thin metal plate from the plating base material and dissolving and removing the photosensitive resin layer, the removed portion becomes an opening, and this thin metal plate is used as a printing mask. This printing mask is
The inner wall of the opening is the smoothest and the printing quality is good as compared with the metal mask manufactured by other manufacturing methods, but there is a drawback that the manufacturing time is long and the cost is high. In addition, sometimes the surface of the inner wall of the opening may be rough due to overexposure to the dry film, or a step may occur when the dry film is used by being stuck together, resulting in a decrease in print quality.

The half etching mask is used for printing cream solder in various pastes, particularly for mounting electronic parts. In this field, due to the miniaturization of electronic components, it has become necessary to mix large components and fine components, but if the mask is thinned to match the fine components, the amount of solder in the large components will be insufficient, and conversely, If the mask is thick for large parts, the solder of fine parts will not come off. As described above, it is a half etching mask (a mask which is partially dug by etching and thinned) that enables printing that is difficult to be compatible with the same plate.

This printing mask is manufactured as follows. That is, first, a mask having a thickness required for a large-sized component is manufactured by the above-described additive mask manufacturing method. Next, a resin for protecting the inner wall surface is filled in the opening within the range of half etching. Finally, after masking unnecessary portions with a resist agent, etching is performed until the thickness is suitable for a fine component. As a result, it is possible to make a mask in which only the fine parts are thinned. In the field of electronic component mounting, it has become possible to print cream solder that mixes large parts / normal parts and minute parts on the same plate, but even if resin filling for inner wall protection is performed, the etching liquid is completely removed. There is a drawback in that it is impossible to completely prevent the penetration and the clean inner wall formed by the additive manufacturing method is roughened by the impregnated etching solution. For this reason, the fine opening, which requires the highest quality, is likely to be roughened most. Furthermore, the drawbacks of the additive manufacturing method that is the manufacturing process of this mask (roughness due to overexposure to the dry film on the inner wall of the opening, and step differences when the dry film is used for bonding may occur) It may occur in the half etching mask as well. Since half-etching is mostly done by hand, there is a large variation, the cost is the highest among metal masks, and the manufacturing time is long.

Further, in the above metal mask, since the punch press mask, the YAG laser mask, the etching mask and the like are not flexible, if there is a convex portion or the like on the printing medium, the mask is used. When trying to make it adhere to the top, a gap is created between the mask and the printing object,
When the paste is filled in the through openings, the paste enters the gap between the mask and the printing medium, causing bleeding in the printed paste pattern. further,
When a paste containing solids is used, the solids adhere to the back surface of the mask, and when the mask is repeatedly used for printing, the solids that adhere increase the gap between the mask and the printing medium. , The bleeding of the printed paste pattern increases.

A metal plate (mainly nickel plate) mask formed by plating, such as an additive mask or a half etching mask, is soft, and when the mask is brought into close contact with the printing medium, The mask is easily deformed by foreign matter and unevenness. For this reason, if the mask near the opening is deformed, when printing is repeated using the mask, the paste enters the back surface of the mask through the gap of the deformed part, causing bleeding in the printed paste pattern and lowering the print quality. There is a drawback that

Further, as the thickness of the plating increases, the roughness of the plating surface increases, and particularly when the paste contains easily deformable solids such as solder particles,
The solid content of the paste that has entered the back surface of the mask may be crushed by being sandwiched between the mask and the material to be printed, and adhered to the mask surface, which is a rough surface. When the mask is repeatedly used for printing, the solid content that has adhered increases the gap between the mask and the printing medium, and when the paste is filled into the through-opening, the gap between the mask and the printing medium becomes large. There is a drawback that the paste enters and the bleeding of the printed paste pattern increases. Further, when the solid content adhered to the mask surface protrudes from the opening, the paste cannot be easily removed from the through opening, and the printing quality of the paste is deteriorated.

Furthermore, as a result of the paste entering the gap between the metal mask and the object to be printed and the back surface of the mask being contaminated by the paste and the solid content of the paste adhering to the back surface of the mask, paste printing is repeatedly performed using the metal mask. When this is done, it is necessary to frequently clean the back surface of the mask and wipe off the paste solid matter attached to the back surface of the mask.

Furthermore, in recent years, paste printing has become finer and finer due to lighter, thinner and smaller paste printing application fields for electronic devices such as printing of solder paste. There is an increasing demand for high-quality paste printing that does not have defects or bleeding in patterns.

[0018]

DISCLOSURE OF THE INVENTION The present inventor has solved the drawbacks of the various metal masks described above and, in order to perform high-quality paste printing of a fine pattern, a method for producing a paste printing mask and a paste. When the printing method was examined, a plastic mask for paste printing was formed by forming a through hole in a pattern using an excimer laser on the plastic plate, and the paste printing was performed using the plastic mask for paste printing. It has been found that various drawbacks of can be solved.

The paste printing using a plastic mask for paste printing (hereinafter referred to as a plastic mask for printing) usually comprises a step of bringing a plastic mask for printing having a fine pattern of through-openings into close contact with a material to be printed, Filling the paste into the through openings of the fine pattern by spreading the paste on the printing plastic mask with a squeegee and removing the excess paste from the mask surface, and then removing the printing plastic mask from the substrate. And a step of forming a fine pattern of the paste on the object to be printed by removing the paste.

Accordingly, in order to perform high-quality paste printing, the paste is completely filled in the through openings, and a part of the paste is printed when the plastic mask for printing is removed from the printing medium. It is necessary that the paste be removed from the through opening in a perfect shape without remaining in the through opening of the plastic mask, that is, the so-called paste filling property and paste removal property should be good. The quality of the filling property of the paste into the through-opening portion and the removal property of the paste from the through-opening portion are affected by the shape of the through-opening portion, the surface roughness (smoothness) of the inner wall of the through-opening portion, and the like.

The through opening of the plastic mask for printing has a burr at the edge of the through opening, a convex shape of the edge of the through opening, a convex shape of the center of the inner wall of the through opening, a step difference of the inner wall surface of the through opening, and a through hole. A shape such as roughness on the inner wall surface of the end portion of the opening does not occur. In addition, the inner wall of the through opening is very smooth, and the filling property of the paste into the through opening and the removal property of the paste are substantially good. However, when the through opening having a particularly fine pattern is formed, there are still two main problems as follows.

That is, first, when a plastic plate which is an object to be processed is subjected to a through-hole forming process of a fine pattern by an excimer laser, where the plastic plate is not in close contact with the processing table, the lower end of the through-opening is formed. A phenomenon in which a thin plastic film remains (hereinafter referred to as "remaining thin film") occurred.

The through opening formed in the plastic mask for printing by the excimer laser usually has a taper that widens upward. However, when paste printing is performed using this plastic mask for printing, the plastic mask for printing is used by turning it upside down during the processing for forming the through opening so that the taper of the through opening becomes wider downward. Therefore, when a thin film remains, the plastic thin film remains on the upper end of the through opening of the printing plastic mask. There is a problem that the thin film of the plastic impedes the filling property of the paste into the through opening and the release property of the paste from the through opening, and high-quality paste printing of a fine pattern cannot be performed.

Secondly, when the plastic plate which is the object to be processed is subjected to the drilling process of the fine pattern by the excimer laser and the plastic plate is in close contact with the processing table, the lower end edge of the through opening is rounded. Phenomenon (hereinafter referred to as "edge chipping") occurred.

When paste printing is performed using the printing plastic mask, the printing plastic mask is used upside down during processing. For this reason, when the edge chipping occurs, the upper end edge of the opening of the fine pattern is rounded. The roundness of the upper edge of the opening hinders the filling property of the paste into the through opening and the releasing property of the paste from the through opening, and there is a problem that high-quality paste printing of a fine pattern cannot be performed.

Therefore, the present invention is proposed to solve these problems. That is, the object of the present invention is to prevent the occurrence of residual thin film or edge chipping, or to minimize edge chipping, and to provide excellent filling properties of the paste into the through openings and removal of the paste from the through openings. An object of the present invention is to provide a method for producing a plastic mask for printing, which enables high-quality printing of patterns.

Another object of the present invention is to provide a paste printing method using a plastic mask for printing, which is excellent in filling the paste into the through-opening and removing the paste from the through-opening. An object of the present invention is to provide a paste printing method that can perform various printing.

A further object of the present invention is to provide a plastic mask for printing which is excellent in filling the paste into the through openings and removing the paste from the through openings, and is capable of performing particularly high-quality printing of fine patterns. To provide.

[0029]

In order to achieve the above object, the invention of claim 1 is a method for producing a printing mask, in which a plastic plate is irradiated with an excimer laser beam to form a through-opening portion. The polymer film that absorbs at least a part of the excimer laser beam is adhered to the surface opposite to the beam irradiation surface, and the excimer laser beam is irradiated to the beam irradiation surface to form a through opening in the plastic plate. A method for producing a plastic mask for printing, which comprises removing the film.

A second aspect of the present invention is the method for producing a plastic mask for printing according to the first aspect, wherein the polymer film is releasably adhered to the plastic plate.

According to a third aspect of the present invention, there is provided a paste printing method in which a printing plastic mask is brought into close contact with a printing medium and the paste is spread on the printing plastic mask to form a paste pattern on the printing medium. In, a polymer film that absorbs at least a part of the excimer laser beam is adhered to the surface of the plastic plate opposite to the beam irradiation surface, and the excimer laser beam is irradiated to the beam irradiation surface to form a through opening in the plastic plate. After that, the printing plastic mask from which the polymer film has been removed is brought into close contact with the substrate to be printed, and the paste is spread on the printing plastic mask to fill the pattern-like through openings, and then the substrate to be printed is printed. The paste pattern is formed on the substrate by removing the plastic mask for printing. A paste printing method to be.

According to a fourth aspect of the invention, in the invention of the third aspect, the thickness of the plastic mask for printing is from 10 μm to
500 μm and a flexural modulus of 20 to 500 Kg
The paste printing method is characterized in that it is f · mm ⁻² .

According to a fifth aspect of the present invention, a printing plastic mask is brought into close contact with an object to be printed, and a paste containing solid particles is spread on the printing plastic mask to form a paste pattern on the object to be printed. In the paste printing method to form, the depth distance from the upper surface of the plastic mask for printing, which has formed a pattern of through-openings on the plastic plate by excimer laser processing, to the narrowest part of the through-openings is included in the paste. The pattern-shaped through openings are formed by forming the printing plastic mask into a size equal to or smaller than ½ of the particle size, and adhering the printing plastic mask onto the printing object, and spreading the paste containing the solid particles onto the printing plastic mask. Part, then remove the plastic mask for printing from the printing object to print the paste pattern A paste printing method characterized by forming on.

According to a sixth aspect of the invention, in the invention of the fifth aspect, the thickness of the plastic mask for printing is from 10 μm to
500 μm and a flexural modulus of 20 to 500 Kg
The paste printing method is characterized in that it is f · mm ⁻² .

According to a seventh aspect of the present invention, in a printing mask formed by irradiating a plastic plate with an excimer laser beam to form patterned through openings, the narrowest part in the through openings from the upper surface of the printing mask. Is a plastic mask for printing, which has a depth distance of up to 25 μm.

According to the invention of claim 8, in the invention of claim 7, the thickness of the plastic mask for printing is from 10 μm to
500 μm and a flexural modulus of 20 to 500 Kg
It is a plastic mask for printing, characterized in that it is f · mm ⁻² .

In the method for producing a plastic mask for printing according to claim 1, since the polymer film is adhered to the surface of the plastic plate opposite to the beam irradiation surface, the thin film left on the bottom surface of the opening just before the penetration by the excimer laser. Cannot wrap around the back side of the plastic plate, and the thin film remains because it is irradiated with the excimer laser beam until the end of the through opening. Further, even if a thin film remains on the polymer film adhered to the plastic plate, since the polymer film is removed after the through opening is formed, the thin film does not remain on the printing plastic mask.

Further, at least a part of the excimer laser beam after the through opening is formed in the plastic plate is absorbed by the polymer film and reaches the processing table while being attenuated, and a part thereof is reflected. Since the reflected excimer laser beam is again absorbed by the polymer film and attenuated, the processing table side edge of the conduction opening of the plastic plate is not ablated by the reflected excimer laser beam, and the edge is chipped. Can be prevented.

In the method for producing a plastic mask for printing according to the second aspect, since the polymer film is releasably adhered to the plastic plate, it is easy to adhere and remove the polymer film.

In the paste printing method according to the third aspect of the present invention, since there is no thin film remaining on the printing plastic mask, and there is no or little edge chipping, the fillability of the paste through opening and the paste through opening of the paste are small. The release property is good, and it is possible to perform high-quality paste printing with no defects in the paste pattern.

Furthermore, since the printing plastic mask is soft and flexible, even if there is unevenness on the surface of the printing object, it flexibly follows and adheres to it, and the printing plastic mask is removed from the printing object. When printing, the printing plastic quickly returns to its original flat state, and the printing plastic mask is not deformed. Therefore,
A gap between the plastic mask for printing and the surface of the printing medium can be prevented or can be made extremely small, and the space between the plastic mask for printing and the printing medium can be reduced when the paste is filled in the through opening. It is possible to prevent the paste from entering the gap. In addition, even if the paste slightly enters the back surface of the plastic mask for printing and the solid content in the paste is crushed by being sandwiched between the mask and the object to be printed, the surface of the plastic plate is extremely smooth. Rarely adheres to the back of the. As a result, the printing plastic mask can be repeatedly used many times to form a bleed-free paste pattern accurately corresponding to the through opening pattern on the printing medium.

Furthermore, since the back surface of the printing plastic mask is hardly soiled by the paste, paste printing can be performed by repeatedly using the printing plastic mask many times without cleaning the back surface or wiping off the dirt.

In the paste printing method of the fourth aspect, since the thickness of the plastic mask for printing is 10 μm to 500 μm and the bending elastic modulus is 20 to 500 Kgf · mm ⁻² , the plastic mask for printing adheres well to the surface of the printing object, Also, when the printing plastic mask is removed from the printing object, the printing plastic mask quickly returns to its original flat state,
The deformation of the printing plastic mask does not occur, and the generation of the gap between the printing plastic mask and the surface of the printing object can be further reduced.

In the paste printing method of the fifth aspect, the depth distance from the upper surface of the plastic mask for printing to the narrowest part of the through opening is not more than half the particle diameter of the solid content contained in the paste. The paste spread on the plastic mask for printing passes through the through opening, and the bottom of the paste is easily scraped off by the upper end of the front opening, and the scraped paste is sufficiently filled in the through opening, In addition, the paste can be easily removed from the through openings, and high-quality paste printing can be performed without a defect in the paste pattern.

In the paste printing method according to the sixth aspect, since the thickness of the printing plastic mask is 10 μm to 500 μm and the bending elastic modulus is 20 to 500 Kgf · mm ⁻² , the printing plastic mask is applied to the printing object. Even when there is a convex part on the printing material when it is brought into close contact with the printing material, it adheres well, and when the printing plastic mask is removed from the printing material, the printing plastic mask quickly returns to its original flat state. By restoring, the plastic mask for printing does not deform, and the generation of the gap between the plastic mask for printing and the printing medium can be further reduced. As a result, it is possible to prevent the paste from entering between the printing plastic mask and the printing object when the through-opening is filled with the paste, and the paste pattern having no bleeding that exactly corresponds to the through-opening pattern is covered. It can be formed on a printed body.

Further, the back surface of the mask is rarely soiled by the paste, and the printing plastic mask can be repeatedly used without cleaning the back surface.

In the plastic mask for printing according to claim 7, since the depth distance from the upper surface of the printing mask to the narrowest part in the through opening is 25 μm or less, the filling property of the paste into the through opening and the paste can be improved. It is easy to remove from the through opening, and high-quality paste printing can be performed without a defect in the paste pattern.

In the plastic mask for printing according to claim 8, the thickness of the plastic mask for printing is 10 μm to 50 μm.
0 μm and a flexural modulus of 20 to 500 Kgf ·
Since it is mm ^-2 , when the printing plastic mask is brought into close contact with the printing object, even if there is a convex portion on the printing object, the printing plastic mask is more closely adhered, and the printing plastic mask is also applied to the printing object. When removed from the printer, the printing plastic mask quickly returns to its original flat state, the printing plastic mask is not deformed, and there is less gap between the printing plastic mask and the substrate. can do. As a result, it is possible to prevent the paste from entering between the printing plastic mask and the printing object when the through-opening is filled with the paste, and the paste pattern having no bleeding that exactly corresponds to the through-opening pattern is covered. It can be formed on a printed body. Further, the back surface of the mask is rarely soiled by the paste, and the plastic mask for printing can be repeatedly used without cleaning the back surface.

[0049]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a method for producing a plastic mask for printing according to the present invention will be described below, but the present invention is not limited to this. In FIG. 10, a 125 μm thick polyimide film 20 is used as a plastic plate, and a silicone adhesive 21 is used.
A polyester film 22 (having a thickness of 20 μm) (having a thickness of 25 μm) is detachably attached.

A plastic plate 35 to which the polyester film 22 with the silicon adhesive 21 is removably attached is cut into a required size, and the polyester film 24 is attached to the polyester frame 24 attached to the mask frame 23 as shown in FIG. Stick with adhesive 25 with the side down,
After the adhesive 25 was cured, the polyester mesh film inside the adhesive 25 was cut off to prepare a plastic mask 26 for printing before processing by the excimer laser as shown in FIG. Note that FIG. 11 shows a state at the time of processing, and when actually used as a printing mask, the upper and lower sides are opposite to those in FIG. 11.

Then, as shown in FIG. 12, the polyester film side of the plastic mask 26 for printing before processing is brought into close contact with the surface of the processing XY table 28 of the excimer laser processing apparatus, and the mask frame 23 is processed by the clamp 27. It was fixed to the XY table 28, and the printing plastic mask 26 before processing was precisely positioned at the irradiation position of the excimer laser beam by moving the processing XY table 28. Next, the excimer laser beam 30 output from the excimer laser oscillator 29 arranged above it.
The polyimide film was irradiated with the light-shielding aperture mask 31, and then through the condenser lens 32 and the lens 33.

In this way, the excimer laser beam oscillated at a wavelength of 249 nm and a pulse frequency of 200 Hz / sec by krypton fluorine gas is condensed by the condenser lens 32 and the lens 33 with an energy density of 1.7 diule / c.
The surface of the polyimide film was irradiated so as to have m ² and ablation processing was performed for 1.25 seconds at a processing speed of about 0.5 μm / pulse. Then, the polyester film was removed together with the silicone adhesive, and the narrowest pitch of 0.
A plastic mask for printing 2 having a pattern of 1 mm
Got 6. The obtained printing plastic mask 26 is
There was no remaining thin film and no edge chipping.

This printing plastic mask 26 is brought into close contact with a printed circuit board made of glass epoxy,
The solder paste containing solid spherical particles having a particle diameter of m to 44 μm is spread on the printing plastic mask 26 to fill the patterned through openings, and then the printing plastic mask 26 is printed from the printing medium. When the paste pattern is formed on the printing object by removing the paste, the filling property of the paste into the through opening and the release property of the paste from the through opening are good, and the pattern on the printed circuit board does not have chipping or bleeding. We were able to perform high-quality paste printing. Also, the back surface of the mask is extremely unlikely to be soiled by the paste, and even when a metal mask is used to print using an additive mask with good print quality, the back surface is wiped off at least every several printings, and tens of times. While it is necessary to wash the back surface every time the printing is performed, the printing plastic mask 26 can be repeatedly used 100 times or more without washing the back surface.

The excimer laser used in the method for producing the plastic mask 26 for printing of the present invention can be subjected to a characteristic process called abrasion which is not found in other lasers (for example, CO ₂ or YAG laser), Particularly, when an organic polymer is a processing target, it exhibits an excellent fine processing capability.

CO ₂ or YAG laser processing mainly uses a wavelength in the infrared region to perform thermal processing, whereas ablation processing using a beam in the ultraviolet region of an excimer laser is also called non-thermal processing. When an organic polymer is irradiated with a laser beam, the molecule that absorbs the energy is excited, and the intermolecular bond is eventually broken and cleaved, and the organic polymer (polymer) decomposes into constituent molecules and becomes a gas. Scatter.

Since this process takes several tens of ns,
Molecules that are said to reach about 6000 ° K when cleaved are 50
00-10,000 m / sec. Since it scatters at the initial velocity and there is no time to give heat to the surroundings, the parts adjacent to the processed part do not suffer from problems such as thermal denaturation like during heat processing, and the processed surface is smooth and extremely smooth. It will be beautiful.

Further, in the laser processing of CO ₂ or YAG, a beam narrowed down is applied to the object to be processed (workpiece), whereas the beam of the excimer laser has a spread, and Some have a beam cross-sectional area with a long side of about 20 mm and a short side of about 8 to 9 mm,
Compared with the processing method using CO ₂ or YAG laser, a wide range of processing can be performed at one time.

In practice, the output beam of the excimer laser may not reach the energy density required for processing, so that it is often used by condensing, and the processing area is several minutes of the original beam cross-sectional area. However, it is a great advantage that surface processing can be performed. Utilizing this feature, for example, when the beam optical path is shielded by an aperture mask with a figure or mark removed, and an excimer laser beam is applied to the plastic plate in the shape of a figure or mark to process it,
A dug portion and a through opening having the same shape are formed on the plastic plate. In this way, it is possible to produce a plastic mask for printing which has excellent smoothness of the inner wall of the through opening. By excimer laser processing, 0. It is possible to manufacture a plastic mask for printing fine patterns up to 1 mm pitch or less.

Further, according to the method for producing a plastic mask for printing of the present invention, a polymer film that absorbs at least a part of the excimer laser beam is adhered to the surface of the plastic plate opposite to the beam irradiation surface, and the excimer laser beam is then attached. After forming a through-opening in the plastic plate and removing the polymer film, there is no "thin film remaining" or "edge chipping", or very little "edge chipping" printing. A plastic mask can be made.

Especially, there is no thin film remaining or edge chipping, or very few edge chipping, and the narrowest pitch of 0. It is possible to produce a plastic mask for printing up to 1 mm or less (possible up to about 0.01 mm pitch). This enables miniaturization of 1/4 to 1/3 or less with respect to the narrowest pitch (0.4 mm to 0.3 mm pitch) in the metal mask. It is presumed that the "medium remaining" does not occur by the method for producing a plastic mask for printing of the present invention due to the following mechanism.

FIG. 1 is a conceptual diagram showing a mechanism of "residual thin film" occurring in a method for producing a plastic mask for printing. (A) shows a part of an opening, (b). Shows the engraved shape in the opening enlarged.
(C) shows the remaining thin film. As shown in FIG. 1 (a), when the beam irradiation surface 1a of the plastic plate 1 is irradiated with the excimer laser beam 2, an opening 3 having an upward taper is formed on the inner wall thereof. As shown, the reflected beam 5 of the excimer laser beam 2 with which the inner wall 4 having a taper is irradiated advances the ablation of the corner portion 6 to form a recessed shape. And FIG.
As shown in (c), when the ablation at the corners does not proceed evenly, the plastic thin film 7 is ablated by the ablation where the plastic plate 1 is not in close contact with the processing table. It receives repulsion and wraps around the back surface 1b of the plastic plate 1. Then, the thin film 7 is not irradiated with the excimer laser and remains at the lower end of the through opening 3.

On the other hand, according to the method for producing a plastic mask for printing of the present invention, since the polymer film is adhered to the surface of the plastic plate opposite to the beam irradiation surface, the opening just before the penetration by the excimer laser is formed. The thin film remaining on the bottom surface cannot wrap around to the back side of the plastic plate, and because the excimer laser beam is irradiated until the end of the through-opening, no thin film residue occurs, and the high-pressure film adhered to the plastic plate is not exposed. Even if a thin film remains on the molecular film, the polymer film is removed after the through opening is formed, so that the thin film does not remain on the printing plastic mask.

FIG. 2 is a conceptual diagram showing the state of the bottom surface of the opening immediately before the penetration by the excimer laser in the method for producing a plastic mask for printing of the present invention. As shown in the figure, at the corner portion 9 between the bottom surface 8 and the inner wall surface 4, the reflected beam 5 reflected by the tapered surface of the inner wall surface 4 and the direct-beam 2 directly radiated from above overlap each other. Since the energy density is high, the ablation process is promoted, and a hollow shape is generated. On the other hand, it shows that the other corner portion 6 has already penetrated and the inner wall surface 4 and the bottom surface 8 are separated. When the number of corners 6 thus separated increases and the number of connection parts decreases, the plastic thin film on the bottom surface 8 is abraded by 50%.
00-10,000 m / sec. Due to the reaction force of the plasmatized molecules that jump out at the initial velocity, the corner portion 9 tries to wrap around the back surface 1b around the portion where only a part is connected. However, since the polymer film 11 that absorbs at least a part of the excimer laser beam is attached below the bottom surface 8 via the adhesive 10, it cannot go around to the back surface 1b of the plastic plate 1 and the through opening. Since the excimer laser beam is irradiated until the end of the part 3, no thin film remains.

Further, it is presumed that the "mechanism for producing a plastic mask for printing" of the present invention does not cause "edge chipping" or can be reduced to a very small extent by the following mechanism.

FIGS. 3A and 3B are conceptual views showing the mechanism of occurrence of "edge breakage". FIG. 3A shows a part of the opening formed, and FIG. 3B shows an enlarged view immediately after the opening penetrates. (C) is an enlarged view of the state of edge loss. FIG.
As shown in (a), when the excimer laser 2 is irradiated onto the plastic plate 1 that is in close contact with the processing table 12, the opening 3 is formed, but as shown in FIG.
After the opening 3 penetrates, the excimer laser beam 2 hits the processing table 12 and is irregularly reflected 2a. As shown in FIG. 3C, the lower end of the through opening 3 of the plastic plate 1 is ablated by the excimer laser beam 13 diffusedly reflected near the lower end of the through opening 3, and the through opening 3 is formed.
Edges are chipped at the lower end of the and rounded 4a.

On the other hand, according to the method for producing a plastic mask for printing of the present invention, since the polymer film is adhered to the surface of the plastic plate opposite to the beam irradiation surface, the through opening is formed in the plastic plate. After the excimer laser beam is attenuated by the polymer film, it reaches the processing table and is partially reflected. Since the reflected excimer laser beam is again absorbed by the polymer film, the plastic plate at the lower end of the through opening is not ablated by the reflected excimer laser beam, and it is possible to prevent the occurrence of edge chipping. it can.

When the plastic plate and the polymer film are penetrated together to form the opening, the excimer laser beam is not attenuated until it reaches the processing table, but the beam after the reflection has the penetration opening. Since the polymer film that is in close contact with the plastic plate at the lower end is absorbed and attenuated, the plastic plate at the lower end of the through opening is not ablated by the reflected excimer laser beam, and the edge chipping phenomenon occurs. Can be prevented. In this case, the polymer film that is in close contact with the plastic plate at the lower end portion of the through opening may be subjected to ablation processing, which may cause edge breakage in the polymer film. Since it is removed, it does not affect paste printing using a printing plastic mask.

When an opening is formed by penetrating both the plastic plate and the polymer film, the excimer laser beam reflected by the processing table directly reaches the inner wall surface of the through opening, but the beam causes the through opening. The inner wall surface is not ablated. This is because the intensity of received light per unit area on the surface of the inner wall of the through-opening decreases due to attenuation due to the reflectance of the processing table surface, reduction of energy density due to scattering, and irradiation from the lower side of the inner wall. Presumed to be.

FIG. 4 is a conceptual diagram showing a state in which the plastic plate and the polymer film are both penetrated by an excimer laser to form an opening in the method for producing a plastic mask for printing according to the present invention. As processing progresses, plastic plate 1 and adhesive 1
0 and the polymer fill 11 are all ablated and disappeared, and the beam 2 is reflected while partially absorbed by the processing XY table 12, and scattered beams 14, 15 and 1 are obtained.
6 and the like occur. The scattered beams 15 and 16 impinge on the inner wall of the opening of the plastic plate 1 that serves as a plastic mask for printing. The scattered beam 15 attenuates the energy density due to scattering and irradiates the inner wall surface 4 at an oblique angle with a large irradiation angle. As a result, the energy density per unit area decreases,
Further, the scattering beam 16 has a smaller irradiation angle to the inner wall surface than the scattering beam 15 and has a distance from the wall surface, and the attenuation of the energy density due to scattering is larger than that of the scattering beam 15. It is assumed that the inner wall surface of the part is not ablated.

Scattered beam 1 reflected near the inner wall surface
No. 4 has small energy scattering, which may cause the lower tip portion of the polymer fill 11 to undergo ablation processing, but after the through opening is formed, the adhesive 10
At the same time, since the polymer film 11 is removed, it does not affect the paste printing using the printing plastic mask.

The plastic mask for printing obtained by the manufacturing method of the present invention is used by reversing the top and bottom at the time of forming the through opening when performing paste printing. Therefore, if no edge chipping occurs, the narrowest part in the through opening is on the upper surface of the printing plastic mask,
Further, even if the edge breakage occurs, it can be extremely reduced, so that the narrowest part in the through opening is formed at a very close depth distance from the upper surface of the printing plastic mask.

FIG. 5A is a cross-sectional view schematically showing the through opening of the printing plastic mask 1 when the edge chipping does not occur, and the narrowest portion W in the through opening is the printing plastic mask. 1 on the upper surface. FIG. 5B is a cross-sectional view schematically showing the through opening of the printing plastic mask 1 when the edge chipping occurs, and the narrowest portion W in the through opening is on the printing plastic mask 1. It is shown that it is at a depth distance H from the surface.

The present inventor studied a method of performing paste printing using the thus-produced printing plastic mask. As a result, the printing plastic mask was brought into close contact with the object to be printed and solid particles were contained. Filling the patterned through openings by spreading the paste on the printing plastic mask, and then removing the printing plastic mask from the printing object to form a paste pattern on the printing object In the method, if the depth distance from the upper surface of the printing plastic mask to the narrowest part in the through opening is not more than half the particle diameter of the solid content contained in the paste, the through opening is filled with the paste. It has been found that it is possible to perform high-quality paste printing because of its excellent properties and ease of releasing paste from the through openings.

In this paste printing method, it is presumed that the excellent mechanism of filling the paste into the through openings and removing the paste from the through openings is due to the following mechanism.

FIG. 6 is a conceptual diagram showing a state in which the paste is filled in a fine patterned through-opening portion having no edge chip in the plastic mask for printing obtained by the manufacturing method of the present invention. 3B shows the start of spreading, (b) shows how the paste is scraped off, and (c) shows how the paste is filled in the openings. As shown in FIG. 6A, the paste 1 is applied on the surface of the printing plastic mask 40 that is in close contact with the object to be printed 19.
When 8 is spread by the squeegee 17, the paste 18 moves while slipping on the mask surface while rolling. As shown in FIG. 6 (b), the paste 18 has openings 3
Passing through the top, the bottom of the paste 18 is scraped off by the upper end 3a of the front opening 3, and as shown in FIG. 6 (c),
The scraped-off paste 18 is filled while moving in the through opening 3 toward the squeegee 17 side.

In this way, the paste 1 is applied to the through opening 3.
When the printing plastic mask 40 filled with 8 is removed from the printing object 19, as shown in FIG. 7, the paste 18 is cleanly removed from the through opening 3, and a fine pattern without chipping or bleeding is formed on the printing object 19. Formed on.

Even if a slight edge chipping occurs, the depth distance from the upper surface of the plastic mask for printing to the narrowest part in the through opening should be less than half the particle diameter of the solid content contained in the paste. For example, as in the above case, the paste can be filled into the through openings and the paste can be easily removed from the through openings, and paste printing of a fine pattern without chipping or bleeding can be performed.

On the other hand, due to the edge chipping, when the depth distance from the upper surface of the printing plastic mask to the narrowest part in the through opening exceeds ½ of the particle diameter of the solid content contained in the paste. As shown in FIG. 8, the bottom of the paste 18 is less likely to be scraped off by the upper end of the front opening, the filling of the paste 18 into the through opening 3 becomes insufficient, and as shown in FIG. When the plastic mask 1 is removed from the material to be printed 19, the paste 18 is caught on the upper end of the opening where the edge is broken,
Since the paste 18 has a poor releasing property, a paste pattern with a part missing is formed on the printing medium 19.

According to the method for producing a plastic mask for printing of the present invention, a plastic mask for printing having no thin film residue and edge defects, or from the upper surface of the printing mask having no thin film residue to the narrowest part in the through opening. Depth distance is 5 μm or less, and if necessary, the depth distance from the upper surface of the printing mask to the narrowest part in the through opening is 10 μm or less, 15 μm or less, 20 μm or less, 25 μm
The following plastic mask for printing can be easily produced.

Such a plastic mask for printing is
It can be appropriately selected depending on the production efficiency and the type of paste used for printing, but it is a plastic mask for printing with no thin film residue and edge defects, or the narrowest part in the through opening from the upper surface of the printing mask with no thin film residue. A plastic mask for printing having a small depth distance is more preferable because it can be applied to all kinds of paste printing and can perform paste printing of a fine pattern without chipping or bleeding.

As the material of the plastic plate in the present invention, an organic polymer material that can be ablated by an excimer laser is used. Even if an organic polymer material that is difficult or impossible to ablate by an excimer laser is used, It can be used by mixing a substance that easily absorbs the wavelength light of an excimer laser such as a carbon powder or an ultraviolet absorber, or by mixing it with an organic polymer material that can be ablated by an excimer laser.

The material of the plastic plate is required to have characteristics required for a plastic mask for printing, namely, 1) chemical resistance which is not attacked by the paste, the solvent contained in the paste, or the cleaning agent at the end of printing. ) Abrasion resistance to withstand use as a printing plate, 3) Mechanical strength that does not cause dimensional error due to elongation even with tension applied to the frame, 4) Low friction and water repellency for easy removal of the printing paste. It is preferable.

Examples of the material of such a plastic plate include organic polymer materials such as polyimide, polyester, epoxy resin, and polycarbonate that are easily ablated, or polyethylene, polypropylene, polyacetal, which is difficult or impossible to ablate. Examples include organic polymer materials such as Teflon that are difficult or impossible to ablate. For the latter, ablation can be performed by mixing substances that easily absorb the excimer laser wavelength light as described above, or by an excimer laser. It can be used by mixing with other organic polymer materials.

The thickness of the plastic plate, that is, the thickness of the plastic mask for printing is preferably about 10 μm to 500 μm, and particularly about 100 μm to 200 μm in paste printing using cream solder.

The printing plastic mask is 20
It is preferable to have a bending elastic modulus of about 500 Kgf · mm ⁻² . By having such a thickness and a flexural modulus, even if there is a convex portion on the printing object, when the printing plastic mask is brought into close contact with the printing object, the printing plastic mask and the printing object are It is possible to eliminate or extremely reduce the gap between and, and it is possible to prevent the paste from entering the gap between the printing plastic mask and the printing medium when the through opening is filled with the paste. As a result, bleeding of the printed paste pattern does not occur. Further, the back surface of the mask is rarely soiled by the paste, and the plastic mask for printing can be repeatedly used without cleaning the back surface.

As the material of the polymer film that absorbs the excimer laser beam used in the method for producing the plastic mask for printing of the present invention, the above-mentioned materials of the plastic plate can be used in the same manner. It is preferable that it has a toughness that does not easily peel off or tear and can be peeled off cleanly. In practice of excimer laser beam processing, it is preferable to use a polymer film of the same material as that used for the plastic plate. The thickness of the polymer film is preferably about 5 μm to 50 μm.

In the method for producing a plastic mask for printing of the present invention, the method of bringing the polymer film into close contact with the surface of the plastic plate opposite to the surface irradiated with the excimer laser beam includes a method of pressing the polymer film onto the plastic plate, Examples include a method in which a larger plastic plate is placed on a molecular film and air is adsorbed by suction, and a method in which a polymer film coated with an adhesive is releasably adhered to the plastic plate. As the adhesive, it is preferable to use one that absorbs the wavelength of the excimer laser, or one that contains a substance that absorbs the wavelength of the excimer laser, or one that transmits the wavelength of the excimer laser, and plastic It is preferable to use an adhesive having a releasability that does not remain on the plastic plate when the polymer film is removed from the plate.

To put the polymer film on the plastic plate via an adhesive, for example, a plastic sheet wound in a roll is unrolled, and an adhesive wound in a roll via release paper is used. The polymer film with the agent may be unwound, and the adhesive surface of the polymer film and the plastic sheet may be brought into close contact with each other and passed through a space between pressure-bonding rollers to be attached, and then wound with a winding roll. This method allows continuous processing from roll to roll, and is also preferable in terms of bonding quality, because it allows bonding without entrapment of air bubbles or wrinkles.

[0089]

According to the method for producing a plastic mask for printing of the present invention, a polymer film that absorbs at least a part of an excimer laser beam is brought into close contact with the surface of the plastic plate opposite to the surface irradiated with the beam, and the surface irradiated with the beam. Since the polymer film is removed after forming a through opening in the plastic plate by irradiating an excimer laser beam, a plastic mask for printing having a fine pattern with no thin film residue or edge chipping or very few edge chipping is produced. can do.

According to the paste printing method of the present invention, since there is no thin film residue on the printing plastic mask, and there is no edge chipping, or there is very little, the filling property of the paste through opening and the paste through opening can be reduced. It is possible to perform high-quality paste printing with no defect in the paste pattern.

Furthermore, since the printing plastic mask is soft and flexible, even if there is unevenness on the surface of the printing object, it flexibly follows and adheres to it, and the printing plastic mask is removed from the printing object. When this happens, the printing plastic mask quickly returns to its original flat state, and deformation of the printing plastic mask does not occur easily.
Therefore, no gap can be generated between the printing plastic mask and the surface of the printing object, or the gap can be extremely reduced. When the paste is filled in the through opening, the printing plastic mask and the printing object are separated from each other. It is possible to prevent the paste from entering the gap between them. In addition, the paste slightly enters the back of the plastic mask for printing,
Even if the solid content in the paste is crushed by being sandwiched between the mask and the material to be printed, the surface of the plastic plate is extremely smooth, so that the solid content hardly adheres to the back surface of the plastic mask for printing. As a result, the printing plastic mask can be repeatedly used many times to form a bleed-free paste pattern accurately corresponding to the through opening pattern on the printing medium.

Further, since the back surface of the printing plastic mask is hardly soiled by the paste, paste printing can be performed by repeatedly using the printing plastic mask many times without cleaning the back surface or wiping off the dirt.

Further, according to the paste printing method of the present invention, a patterned through opening is formed in the plastic plate by excimer laser processing, and the upper surface of the printing plastic mask to the narrowest part of the through opening is formed. The depth distance is formed to be ½ or less of the solid content particle diameter contained in the paste, and this printing plastic mask is brought into close contact with the object to be printed, and the paste containing the solid content particles is placed on the printing plastic mask. The pattern-like through opening is filled by spreading, and then the printing plastic mask is removed from the printing object to form the paste pattern on the printing object. It has excellent filling properties and paste release properties from the through openings, especially for high-quality printing without chipping or bleeding of fine patterns. Ukoto can.

Furthermore, according to the paste printing method of the present invention, the number of times the mask is cleaned can be greatly reduced.

Further, in the printing plastic mask of the present invention, in the printing mask in which the plastic plate is irradiated with the excimer laser beam to form the through holes in the pattern, the through holes are formed from the upper surface of the printing mask. Since the depth distance to the narrowest part is less than 25 μm, there is no thin film residue or edge chipping, or very little edge chipping, fillability of the paste into the through opening and paste from the through opening. It is possible to perform high-quality printing with excellent bleeding property, and in particular, for fine patterns without chipping or bleeding.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing a mechanism in which “a thin film remains” occurs in a method for producing a plastic mask for printing,
(A) shows a part of the opening is formed,
(B) is an enlarged view of the cut-out shape in the opening, (c)
Indicates the remaining thin film.

FIG. 2 is a conceptual diagram showing the state of the bottom surface of the plastic plate opening immediately before penetration by an excimer laser in the method for producing a printing plastic mask of the present invention.

FIG. 3 is a conceptual diagram showing a mechanism in which “edge chipping” occurs in a method for producing a plastic mask for printing, and (a) shows a part of an opening formed,
(B) shows a state immediately after the opening penetrates, and (c) shows a state of edge chipping.

FIG. 4 is a conceptual diagram showing a state in which the plastic plate and the polymer film are both penetrated by an excimer laser to form an opening in the method for producing a plastic mask for printing of the present invention.

5A and 5B are views showing a through opening, wherein FIG. 5A is a cross-sectional view schematically showing the through opening when an edge chipping does not occur, and FIG. 5B is a sectional view schematically showing the through opening when an edge chipping occurs. Is.

FIG. 6 is a conceptual diagram showing how a paste is filled in a fine patterned through-opening portion having no edge chipping in a printing plastic mask obtained by the manufacturing method of the present invention, and FIG. Shows how it started,
(B) shows how the paste is scraped off, and (c) shows how the paste is filled in the openings.

FIG. 7 is a conceptual diagram showing a state in which the paste escapes from the through opening and a fine pattern of the paste is formed on the printing medium.

FIG. 8 is a conceptual diagram showing a state where filling of paste into a through opening is insufficient due to edge chipping.

FIG. 9 is a conceptual diagram showing a state in which the paste is caught on the upper end portion of the opening portion where the edge chipping occurs, the paste release property deteriorates, and a partially cut paste pattern is formed on the printing medium. is there.

FIG. 10 is a cross-sectional view schematically showing an example of a plastic plate when it is used in the method for producing a printing plastic mask of the present invention.

FIG. 11 is a cross-sectional view schematically showing an example of a printing plastic mask before being processed by an excimer laser.

FIG. 12 is a cross-sectional view schematically showing an example of a state of processing by an excimer laser processing device.

[Explanation of symbols]

 1 plastic plate 2 excimer laser beam 3 opening 4 inner wall 5 reflected beam 6 corner 7 thin film 8 bottom of opening 9 corner 10 adhesive 11 polymer film 12 processing table 13 diffusely reflected excimer laser beam 14 scattered beam 15 scattered beam 16 Scattered beam 17 Squeegee 18 Paste 19 Printed material 20 Polyimide film 21 Silicon adhesive 22 Polyester film 23 Mask frame 24 Polyester gauze 25 Adhesive 26 Plastic mask for printing before processing 27 Clamp 28 XY table for processing 29 Excimer laser oscillator 30 Excimer laser beam 31 Aperture mask for shading 32 Condenser lens 33 Lens 40 Plastic mask for printing

Claims (8)

[Claims] 1. A method of manufacturing a printing mask for irradiating a plastic plate with an excimer laser beam to form a through opening, wherein at least a part of the excimer laser beam is absorbed on the surface of the plastic plate opposite to the beam irradiation surface. A method for producing a plastic mask for printing, which comprises contacting a polymer film, irradiating an excimer laser beam on a beam irradiation surface to form a through opening in a plastic plate, and then removing the polymer film. 2. The method for producing a plastic mask for printing according to claim 1, wherein the polymer film is releasably adhered to the plastic plate. 3. A paste printing method for bringing a plastic mask for printing into close contact with an object to be printed and spreading a paste on the plastic mask for printing to form a pattern of the paste on the object to be printed. A polymer film that absorbs at least a part of the excimer laser beam is adhered to the surface opposite to the beam irradiation surface, the excimer laser beam is irradiated to the beam irradiation surface to form a through opening in the plastic plate, and then the polymer film Adhere the plastic mask for printing from which the
It is characterized in that the paste is spread on the printing plastic mask to fill the pattern-like through openings, and then the printing plastic mask is removed from the printing object to form a pattern of the paste on the printing object. And paste printing method. 4. The thickness of the plastic mask for printing is 1
0 μm to 500 μm and a bending elastic modulus of 20 to 5
The paste printing method according to claim 3, wherein the paste printing method is 00 Kgf · mm ⁻² . 5. A paste printing method in which a printing plastic mask is brought into close contact with an object to be printed, and a paste containing solid particles is spread on the printing plastic mask to form a paste pattern on the object to be printed. In the method, the depth distance from the upper surface of the plastic mask for printing having a pattern of through-openings formed on a plastic plate by excimer laser processing to the narrowest part of the through-openings is 2 times the solid content particle diameter included in the paste. Less than one-half,
The plastic mask for printing is brought into close contact with the object to be printed, and a paste containing solid particles is spread on the plastic mask for printing to fill the pattern-like through openings, and then the object to be printed is printed from the object to be printed. A paste printing method, wherein a paste pattern is formed on an object to be printed by removing a plastic mask. 6. The thickness of the plastic mask for printing is 1
0 μm to 500 μm and a bending elastic modulus of 20 to 5
The paste printing method according to claim 5, wherein the paste printing method is 00 Kgf · mm ⁻² . 7. A printing mask in which a plastic plate is irradiated with an excimer laser beam to form a pattern of through openings, and a depth distance from an upper surface of the printing mask to a narrowest part of the through openings. Is 25 μm or less, a plastic mask for printing. 8. The thickness of the printing plastic mask is 1
0 μm to 500 μm and a bending elastic modulus of 20 to 5
The plastic mask for printing according to claim 7, wherein the plastic mask is 00 Kgf · mm ⁻² .