JP2013075384A - Printing mask, printing mask frame coupler, and solar cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printing mask frame coupler holding high printing performance with small deformation in an opening shape during manufacturing and printing of a printing mask, in the printing mask having a thin linear opening.SOLUTION: In a combination plate comprising a printing mask having a thin linear opening, a printing mask frame coupler is configured so that tension of the thin linear opening in a longitudinal direction is larger than that in a lateral direction. An opening for tension buffering and a printing mask holding spacer are provided outside a printing pattern of the printing mask.

Description

  The present invention relates to a printing mask, a printing mask frame assembly, and a solar battery cell used for paste printing.

  Currently, a printing mask having a printing opening formed on a flat plate is generally used for forming a circuit board such as a printed wiring board.

  When printing a conductive paste on a substrate using a printing mask, a printing mask is stretched on an outer frame (hereinafter referred to as “frame”) made of metal or hard resin (hereinafter referred to as “printing”). In general, it is used by being set in a printing apparatus in “a mask frame combination”.

  As for the print mask frame assembly, a combination plate in which a print mask is stretched on a frame (hereinafter referred to as “screen frame”) in which a screen mesh (紗) is stretched is mainly used.

  In the combination plate, it is necessary to attach a printing mask on which a printing opening is formed with a tensile force applied to the screen frame. Therefore, the screen mesh is used for the purpose of applying tension to the printing mask. In the combination plate, a printing mask (adhesive is applied to the peripheral part. This fixing surface is called “combination part”) is fixed to the center of the screen frame on which the screen mesh is stretched, and the printing mask is fixed. It is formed by cutting out the screen mesh in the inner part of the surface. When the screen mesh is present in the opening pattern part on the printing mask, the screen mesh is cut off when the combination plate is used. This is because the omission becomes worse. Therefore, the screen mesh is cut out to expose the opening pattern of the printing mask.

In general, the combination plate is manufactured in the following steps.
1) Clamp the four sides of the screen mesh.
2) Pull the four clamped sides and apply predetermined tensions in two orthogonal directions (X direction and Y direction).
3) Adhere and fix the screen mesh under tension to the frame.
As described above, a screen frame to which the screen mesh in a tensioned state is fixed is obtained.

4) Next, a printing mask (having a printing opening formed thereon. Adhesive is applied to the peripheral portion) is placed on the screen mesh in the screen frame and fixed.
At this time, the printing mask surface portion is in a state where the printing mask and the screen mesh overlap.
5) Cut out the screen mesh in the inner part of the fixing surface (peripheral part) of the printing mask.
As a result, the opening of the printing mask surface is exposed without being obstructed by the screen mesh.

  Since the periphery of the printing mask is fixed to the screen mesh, the tension of the screen mesh is applied. That is, the printing mask frame assembly obtained by the above process has a printing mask in a state where tension is applied by the screen frame.

As a printing method using the printing mask frame combination, there are off-contact printing and on-contact printing. With off-contact printing, the printing mask frame assembly is placed horizontally, away from the substrate, placed on the printing mask, a paste is placed on the printing mask, and the squeegee is moved while pressing it toward the substrate on the printing mask. This is a printing method in which a paste is filled in a portion, and when the squeegee passes, separation of the plate occurs and the paste is placed on the substrate contact portion. On-contact printing means that the printing mask frame assembly is brought into close contact with the substrate, the paste to be printed is placed on the printing mask, and the squeegee is moved horizontally on the printing mask to fill the opening with the paste. In this printing method, the plate is peeled from the substrate after paste printing, and the paste is transferred to the substrate contact portion.

By the way, in the recent production of solar cells, the ratio of the length in the short direction to the long direction on the substrate is 1:10 or more (preferably 1: 500 or more, more preferably 1: 1500 or more). There is a need for printing elongated electrodes. At this time, if printing is to be performed using the combination plate as described above, the opening for printing corresponds to this, and the ratio of the length in the short-side direction to the long-side direction is 1:10 or more (preferably 1). : 500 or more, and more desirably 1: 1500 or more) It is necessary to form a thin line-like opening (hereinafter referred to as a “fine line-like opening”) shaped like an elongated groove.
However, when such a fine line-shaped opening is provided in a printing mask to produce a combination plate, there is a problem that the shape of the fine line-shaped opening is deformed by a tension applied during the production.

As a solution to this problem, a printing mask is disclosed in which a bridging portion is provided in a fine line-shaped opening to suppress deformation of the shape.
JP-A-2005-116786

However, if a bridging part is provided in the fine line-shaped opening, the bridging part inhibits the filling of the paste during paste printing, and paste transferability at the corresponding part of the bridging part is lowered. As a result, there is a problem that the height of the paste on the completed substrate is partially reduced. That is, the height of the paste at the portion corresponding to the cross-linked portion is hindered by the cross-linked portion and becomes low. On the other hand, it is conceivable to reduce the number of bridges or reduce the number of bridges in order to suppress the deterioration of printing performance, but in this case, the bridges become brittle, so they break easily during printing and maintenance after printing. However, there is a problem that the printing mask cannot be used immediately.

  In addition, it is conceivable to use a metal mesh as a reinforcing bridge, but the printing accuracy is further reduced.

In order to solve this problem, the applicants applied the mask for printing to the screen frame in which the tension in the Y direction of the screen mesh is stronger than that in the X direction so that the longitudinal direction of the fine line-shaped opening faces in the Y direction. Invented a printing mask frame assembly (hereinafter referred to as “anisotropic tension mask plate”) which is fixed to the screen mesh and suppresses deformation of the opening, and a method for producing the same, and applied for a patent.
Hereinafter, in the screen frame, anisotropic tension mask plate and printing mask frame assembly, the direction in which the tension is strong is referred to as the Y direction, and the direction in which the tension is weak is referred to as the X direction.
Japanese Patent Application No. 2010-085734

This anisotropic tension mask plate has a remarkable effect in solving the above-mentioned problem, and for the first time in a printing mask having a fine line-shaped opening but no cross-linking structure, enables high-precision paste printing for the first time. . However, even in this case, tension in the X direction is applied to some extent, and therefore, in the printing mask surface, the X direction (hereinafter referred to as “printing pattern”) in the region where the fine line-shaped opening is provided (hereinafter referred to as “printing pattern”). Only the fine line opening near both ends (in the short direction of the fine line opening) is more susceptible to the tension in the X direction than the other fine line openings, and thus large deformation occurred. This has caused a phenomenon that the width of the fine line of the paste after printing varies. Here, the amount of deformation is the width of the fine line-shaped opening, causing a maximum expansion of about 0.040 mm from the design value, but this is preferably 0.010 mm or less.

  In addition, when the substrate and the printing mask are brought into close contact during printing, the printing mask deforms following the step at the edge of the substrate, so that a slight gap is formed between the printing mask and the substrate. As a result, there has been a problem that the bottom of the fine line of the paste after printing is blurred.

There is concern that these may decrease the light collection rate and deteriorate the power generation efficiency as the electrodes of the solar battery cells, and further, as the electrode circuit is further miniaturized in the future, it is predicted that it will become a problem. Was desired.

  The present invention provides a printing mask, a printing mask frame assembly, and a printing mask frame assembly, in which the deformation of the fine line opening due to tension is small even when the fine line opening is provided, without sacrificing transferability of the printing paste. It aims at solving the subject of obtaining the produced photovoltaic cell.

The printing mask according to claim 1 of the present invention is a printing mask having a fine line-shaped opening with a ratio of the length in the short side direction to the long side direction of 1:10 or more,
A printing mask characterized in that an opening for tension buffering is provided outside the area of the printing pattern,
Moreover, the printing mask according to claim 2 comprises:
2. The printing mask according to claim 1, wherein two or more openings for buffering tension are arranged in a broken line shape in a longitudinal direction of the thin line opening.
Moreover, the printing mask according to claim 3 is:
When two or more openings for buffering the tension are arranged in a broken line shape in the longitudinal direction of the thin line-shaped opening, the upper and lower ends thereof are arranged in a staggered manner. Item 2. A printing mask according to item 2,
Moreover, the printing mask according to claim 4 comprises:
4. The printing mask according to claim 2, wherein an interval in the X ′ direction of the dashed-line tension buffering opening is 0.05 mm or more and 5.0 mm or less,
Further, the printing mask according to claim 5 is:
The printing mask according to any one of claims 2 to 4, wherein an interval in the Y 'direction between the small openings constituting the broken-line tension buffering opening is 1 mm or more and 10 mm or less,
Further, the printing mask according to claim 6 is:
6. The printing mask according to claim 2, wherein a length of a small opening constituting the broken-line tension buffering opening in the Y ′ direction is 5 mm or more and 30 mm or less,
Further, the printing mask according to claim 7 is:
The length in the X ′ direction of the tension buffer opening is 0.05 mm or more and 10 mm or less, and the printing mask according to claim 1,
Moreover, the printing mask according to claim 8 comprises:
The printing mask according to any one of claims 1 to 7, wherein the tension buffer opening and the printing pattern are separated by 10 mm or more in the X ′ direction.
Further, the printing mask according to claim 9 is:
The length of the tension buffer opening in the Y ′ direction is not less than 0.5 times and not more than 1.5 times the length of a side of an adjacent print pattern. It is a printing mask as described,
Moreover, the printing mask according to claim 10 comprises:
The printing mask according to any one of claims 1 to 9, wherein a spacer for holding the printing mask is provided in a region outside the printing pattern on the surface of the printing mask that contacts the substrate,
Moreover, the manufacturing method of the mask frame combination for printing of Claim 11 is as follows.
A method for producing a printing mask frame assembly in which a printing mask is stretched on a screen frame via a screen mesh,
Stretching the screen mesh in a state where the ratio of the tension in the X direction and the Y direction is 1: 1.5 or more and 1: 2.8 or less in the frame;
The step of adhering the periphery of the printing mask to the screen mesh in a state where the longitudinal direction of the fine line-shaped opening of the printing mask is substantially the Y direction. ,
Cutting the screen mesh of the inner part of the printing mask fixing part;
It is a manufacturing method of the mask frame combination for printing characterized by having,
Moreover, the mask frame assembly for printing according to claim 12 is:
A printing mask frame assembly in which the printing mask according to any one of claims 1 to 10 is stretched on a screen frame through a screen mesh in a state where the longitudinal direction of the fine line-shaped opening is substantially in the Y direction. There,
A printing mask frame assembly, wherein a ratio of tension in the X direction and the Y direction in the printing mask is from 1: 1.3 to 1: 2.3,
Moreover, the manufacturing method of the mask frame assembly for printing of Claim 13 is as follows.
A method for producing a printing mask frame assembly in which a printing mask is stretched on a screen frame via a screen mesh,
Stretching the screen mesh in a state where the ratio of the tension in the X direction and the Y direction is 1: 1.5 or more and 1: 2.8 or less in the frame;
A step of fixing the periphery of the printing mask to the screen mesh in a state in which the longitudinal direction of the fine line-shaped opening of the printing mask is substantially the Y direction. ,
Cutting the screen mesh of the inner part of the printing mask fixing part;
A step of providing a spacer for holding the printing mask on the substrate contact surface of the printing mask;
It is a manufacturing method of the mask frame combination for printing characterized by having,
Moreover, the mask frame assembly for printing according to claim 14 is:
A printing mask frame assembly in which the printing mask according to any one of claims 1 to 9 is stretched on a screen frame through a screen mesh in a state where the longitudinal direction of the fine line-shaped opening is substantially in the Y direction. ,
The ratio of the tension in the X direction and the Y direction in the printing mask is 1: 1.3 or more and 1: 2.3 or less, and the printing mask is held in a region other than the substrate contacting portion of the substrate contacting surface of the printing mask. A mask frame assembly for printing, characterized by being provided with a spacer for,
Moreover, the mask frame assembly for printing according to claim 15 is:
The printed mask frame assembly according to any one of claims 12 and 14, wherein the printed mask frame assembly is for manufacturing an electrode of a substrate for a solar cell.
Moreover, the mask frame assembly for printing according to claim 16,
A solar battery cell manufactured using the printing mask frame assembly according to claim 15.

The above-mentioned printing mask is particularly effective when used in a printing mask frame assembly for producing thin wire electrodes such as electrodes of solar cell substrates.

  The above production method is particularly effective in the production of a printing mask frame assembly for producing thin wire electrodes such as electrodes of solar cell substrates.

  Further, the printing mask frame assembly is particularly effective in the case of manufacturing fine wire electrodes such as electrodes of solar cell substrates.

  According to the printing mask frame assembly manufactured according to the present invention, there is no cross-linking in the opening, the deformation of the opening at the time of stretching is small, and the deformation of the opening at the time of printing is also small. High-precision paste printing is possible.

It is a printing mask of this invention, (a), (b) is an example of the opening part for tension buffering Dotted opening for tension buffering Printing mask with and without spacers and paste thin line The form of the spacer (a) is the one with the plate attached, (b) is the one attached to the printing mask by plating after the plate is attached, (c) is the one formed integrally with the printing mask by the plating method, (d ) Is a tape frame attached after printing mask frame assembly. Manufacturing process diagram of mask frame assembly for printing according to the present invention Printed paste fine line and dimension measurement location Summary of Comparative Example 6

Embodiments of the present invention will be described below with reference to the accompanying drawings.

  The conventional anisotropic tension mask plate is desirably manufactured so that the tension of the screen mesh is as isotropic (within ± 5%) as much as possible. On the other hand, it has been found that the problem can be solved without providing crosslinking by providing tension anisotropy in a printing mask having fine line-shaped openings.

Here, as a method of adjusting the tension at the time of manufacturing the screen frame, a method of clamping and pulling four sides of the screen mesh is general, but is not limited thereto.
Moreover, it is considered that the upper limit of the tension ratio of the screen mesh is about 1: 3. When trying to give a high ratio exceeding this, if the tension in the X direction is made constant and the tension in the Y direction is adjusted strongly, the screen mesh breaks, the tension in the Y direction is kept constant, and the tension in the X direction is increased. In the case of weakening, a problem occurs when the mask frame assembly for printing is peeled off from the substrate after printing.

The effect is obtained when the ratio of the tension in the X direction and the Y direction of the screen mesh is 1: 1.5 or more, but more preferably 1: 2 or more and 1: 2.8 or less.
When attention is paid to the tension ratio on the printing mask surface of the printed mask frame assembly after completion, the effect can be obtained at 1: 1.3 or more, but 1: 1.5 or more and 1: 2. It is more desirable if it is 3 or less.
If it is less than this, the deformation of the fine line-shaped opening becomes large and the shape of the fine line of the paste is liable to occur, and if it is larger than this, as described above, there is a possibility that the plate separation after printing may be deteriorated. is there.

However, such tension anisotropy alone cannot completely suppress the deformation in the X direction due to the tension applied to the printing mask, and the deformation in the X direction of the openings near both ends of the print pattern has occurred. Is as described above.

  On the other hand, the printing mask according to the present invention is provided with an opening that is not used for printing inside the printing mask and has a function of buffering the tension, thereby absorbing the tension in the X direction. The deformation in the X direction of the opening due to the tension of the screen mesh can be almost completely eliminated. Further, by providing a printing mask holding spacer on the substrate contact surface, the substrate adhesion of the printing mask during printing was improved.

There are various forms of the opening for tension buffering. FIG. 1 illustrates an effective opening configuration. For example, an elongated slit-like opening (a) of a single line, an opening pattern (b) in which short openings are arranged in a broken line, and the like can be mentioned. In addition, a method of forming an integral pattern as a whole by arranging small openings such as a circle and a polygon is conceivable, but in any case, the pattern is preferably an elongated shape facing the Y ′ direction. .
Here, the longitudinal direction of the fine line-shaped opening in the printing mask is referred to as the Y ′ direction and the short direction is referred to as the X ′ direction, and is distinguished from the X direction and the Y direction in the screen frame or the like (that is, the printing mask frame). In the combined body, X and X ′, and Y and Y ′ are directed in substantially the same direction.) Hereinafter, the same notation is used depending on the case.

Here, when the tension buffer opening is the slit-shaped opening, the width is preferably 0.05 mm or more and 10 mm or less, and more preferably 0.10 mm or more and 1.0 mm or less, in the sense that the effect is effectively exhibited. . If the thickness is too thick, the shape of the printing mask becomes unstable, which is not preferable because unexpected deformation is likely to occur when the printing mask is fixed to the screen. In addition, there is a problem in that the tension buffering effect is lowered since the vicinity of the center in the longitudinal direction of the opening portion is easily drawn even after the sticking.

  Here, in order to increase the effect without increasing the tension buffer opening, the number of the tension buffer openings is not limited to one, and a plurality of openings may be arranged side by side at intervals. In this case, the narrower the distance in the X ′ direction between the tension buffer openings (see 23 in FIG. 2), the easier it is to absorb the tension, so the buffer effect tends to increase. Specifically, it is preferably 0.05 mm or more and 5.0 mm or less, and more preferably 0.05 mm or more and 1.0 mm or less. Here, when it is less than 0.05 mm, there is a problem in that the interval is too narrow, and the part that isolates them is easily broken.

Further, it is effective that the position of the tension buffer opening is provided away from the print pattern so that the influence of the deformation due to the tension is not given to the fine line-shaped opening. In this case, the distance is preferably 10 mm or more, and more preferably 20 mm or more. Here, this distance is determined to be the shortest distance in the X ′ direction between the fine line-shaped opening at the end of the printed pattern and the tension buffering opening adjacent thereto (see 511 in FIG. 5).

On the other hand, FIG. If a plurality of broken lines are provided, it is more effective to shift the positions of the upper and lower ends of adjacent broken lines than to make them coincide. This is because when the positions of the upper and lower ends are matched (a), there is no opening in the space between the openings constituting the broken line (hereinafter referred to as “small openings”), and there is a material for the printing mask. Unlike the part with and without the small opening as a whole, the balance of the X ′ direction is poor, but when it is shifted to a certain extent (b), the small opening in the X ′ direction. This is because the space part is switched and the tension is buffered in a well-balanced manner. At this time, it is more effective that the amount of shifting is a length of one small opening or less, and shifting in a substantially periodic zigzag pattern.
(B) shows the case where the adjacent broken lines are arranged by shifting the positions of the upper and lower ends. In the figure, the case where there are three broken lines is shown as an example. However, the embodiment is not limited to this, and the effect can be achieved when there are two or more broken lines.

If the length of the small opening in the Y ′ direction is too short, it is difficult to cause deformation due to tension and the effect is reduced, and therefore, the length is preferably 5 mm or more and 30 mm or less, and more preferably 10 mm or more and 30 mm or less. Further, the interval between the small openings in the Y ′ direction is preferably 1 mm or more and 10 mm or less in order to effectively exert the tension buffering effect. On the other hand, as described above, the width in the X ′ direction is preferably 0.05 mm or more and 10 mm or less, and more preferably 0.1 mm or more and 1.0 mm or less. Further, as described above, the narrower the interval in the X ′ direction between the broken lines, the easier it is to exert the tension buffering effect.

Here, even if it takes any form of the tension buffering opening, the total length is 0.5 times the length of the side of the print pattern parallel to this in the sense that it effectively shows the tension buffering effect. It is preferably 1.5 times or more. When it is 0.5 times or less, the tension buffer opening when subjected to tension becomes difficult to be deformed, and the effect is reduced. Further, it is particularly preferable that the length is substantially the same as the side length of the print pattern, specifically 0.9 to 1.1 times.

Also, by providing a printing mask holding spacer on the printing mask printing surface that does not come into contact with the substrate, a fine line-shaped opening is created when the printing mask deforms following the step of the substrate during printing. Can be eliminated.

FIG. 3 shows the state of deformation of the printing mask during printing when the printing mask holding spacer is not provided (a) and when it is provided (b). In (a), the printing mask is deformed by the substrate edge due to the pressure of the squeegee, so that the edge of the printing pattern is lifted from the substrate. If the printing is performed as it is, the paste fine line printed at the fine line-shaped opening near the end of the print pattern becomes a shape in which the base is blurred (36). The mask is not deformed. As a result, the thin paste line printed in this way maintains a clean rectangle with no blurring at the bottom, even at the end of the print pattern (37).

This spacer can be formed by various methods. For example, it is conceivable that a plate having a thickness corresponding to the substrate is stuck outside the substrate contact portion. At this time, the plate needs to be sized and arranged so as not to block the function of the opening for buffering the tension. If the method of sticking is to simplify the process, it is effective to use a plating method if sticking with an adhesive or emphasis on fastness. In this method, the plate is coated by forming a plating film on the printing mask having the plate attached with an adhesive. This is particularly effective when a printing mask, which will be described later, is produced by a plating method. That is, immediately before the plate thickness of the printed pattern portion is formed to a desired thickness, the plating is temporarily stopped, the plate is attached to a desired location, and further plating is performed on the plate, thereby printing mask. A spacer can be firmly formed on the top. In this case, it is necessary to use a metal piece for the plate, and in the case of electroplating, the metal piece and the mask surface for printing can be electrically connected by means such as using a conductive adhesive. Need to be glued.
Further, if the plating film itself is a spacer, it can be made more robust. This is a method in which, after the printing mask is manufactured, the surface of the printing mask is processed by photolithography so that only the portion where the spacer is desired is plated, and a plating film is formed on the portion by plating. This is also an effective method particularly when a printing mask is produced by a plating method.
On the other hand, when it is desired to simplify the process, there is a method in which a printing mask is fixed to a screen plate, and after a fixed internal mesh is cut off, a spacer is provided on a portion of the substrate contact surface other than the substrate contact portion. At this time, even if a thick tape is applied as the spacer material, a sufficient effect can be obtained. In this case, since the printing mask is already stretched on the screen plate, there is no problem even if the tension buffer opening is closed. Here, the thickness of the spacer is preferably about the same as that of the substrate. For example, in the case where the substrate is a wafer that prints an electrode of a solar cell, it is generally preferably 100 to 150 μm.
FIG. 4 shows examples of spacer forms. (A) Attached a plate, (b) Attached to a printing mask after plating, (c) A plate formed integrally with a printing mask by plating, (d) A printing The tape frame is pasted after preparing the mask frame assembly for use.

Examples of the method for producing a printing mask include an etching method, a plating method, a laser processing method, a machining method such as drilling, and the like. In addition, examples of the material include metals such as nickel, stainless steel, and aluminum, resins such as polyimide, and composite structures of the metals and resins. A suitable material should be selected depending on the processing method selected.

By using the printing mask thus obtained as a printing mask member for an anisotropic tension mask plate, a printing mask frame assembly having a printing performance exceeding that of a conventional anisotropic tension mask plate is manufactured. Can do.

As a result, it is possible to obtain a combination plate having a printing mask having a fine line-shaped opening portion in which the ratio of the length in the short side direction to the long side direction (hereinafter referred to as “aspect ratio” in some cases) is 1:10 or more. It became. In the case of using a printing mask having a fine line-shaped opening having an aspect ratio exceeding 1: 500, further 1: 1500, the effect is more remarkable.

  In addition, the above-mentioned “thin line-shaped opening having a ratio of the length in the short side direction to the longitudinal direction of 1:10 or more” means an opening having an aspect ratio of 1:10 or more that is not cross-linked, as well as a cross-linked portion. This includes the case where the aspect ratio of the opening between the bridges and the side, in other words, the opening of the part without the bridge, is 1:10 or more.

  At this time, it is not necessary that all the openings on the printing mask are fine line openings in this range. Further, it is not essential that the Y ′ direction of all the thin line-shaped openings is directed to the Y direction. That is, it is only necessary to have fine line-shaped openings and the Y ′ direction of the main fine line-shaped openings is directed to the Y direction or the direction close to the Y direction. In the above description, “substantially Y direction” is the purpose.

In addition, if a printing mask frame assembly is produced as described above and printing is performed as it is, the paste may enter the tension buffer opening and may wrap around the printing surface. This can be easily prevented by closing the tension buffering opening with a tape, and the appearance of the product is improved. At this time, the tape may also serve as the printing mask holding spacer.

[Example 1]
Examples of the present invention will be specifically described below.
An example of the printing mask, the printing mask frame assembly, and the manufacturing method thereof according to the present invention is shown in FIG.
For producing the printing mask frame assembly 516, the tension ratio of the screen mesh 53 is set to X:
The screen frame 51 in which Y = 1: 2 is set and the screen mesh 53 is stretched on the frame 52 is used, and the Y ′ direction of the openings 56, 57, and 58 of the printing mask 55 is substantially the Y direction of the screen frame. It was fixed so as to face in the same direction (c). The size of the screen frame 51 is 350 mm in the X direction and 350 mm in the Y direction.

  At this time, the measurement values of the tension gauge for measuring the screen frame (STG-75, manufactured by Protech Inc., hereinafter referred to as “tension gauge 1”) are 2.0 mm in the X direction of the frame and 1.0 mm in the Y direction. As for the tension ratio, X: Y was 1: 2. In addition, the general tension gauge including the tension gauge used this time places a weight on the screen mesh and measures the sinking amount of the weight, so the unit of measurement value is “mm”. The larger the tension, the closer to 0. Here, the “tension ratio” or “tension ratio” in the present invention is the ratio of the reciprocal of the measured value. In the present invention, the tension gauge 1 was placed near the center of the surface of the screen frame and the tension was measured.

Here, the size of the printing mask 55 was 260 mm × 260 mm, the thickness was 0.05 mm, and it was produced by nickel electroplating (a). The shape of the opening of the printing mask 55 is 0.04 mm in the X ′ direction and 38 mm in the Y ′ direction, and a fine line-shaped opening having a length of 74 mm (ratio 1: 475). 67 portions 57 (aspect ratio 1: 925) and 38-mm thin wire-like openings 58 (aspect ratio 1: 475) were arranged at intervals of 2.3 mm in the X ′ direction. Moreover, the space | interval of the Y 'direction between the thin wire-like opening parts 56, 57, and 58 is 2 mm. Further, tension buffering openings are provided in regions between the left and right ends of the printing mask and the printing pattern with the Y ′ direction as an axis. The tension buffer opening has a broken line shape, the length of one small opening is 15 mm, the width is 0.10 mm, the interval in the Y ′ direction is 7 mm, and the broken line is 3 in 1 mm intervals in the X ′ direction. The upper and lower ends were shifted and arranged in a staggered pattern (510).
The distance between the opening at the left or right end of the printing pattern and the tension buffering opening adjacent thereto (hereinafter referred to simply as “distance between the printing pattern and the tension buffering opening” (511)) is 10 mm. there were.

The printing mask frame assembly 516 is provided with a printing mask holding spacer (515) in a portion other than the substrate contact portion. The spacer is obtained by adhering a printing mask to a screen plate and then affixing a resin reinforcing tape, and the spacer has a thickness of about 100 μm.

  The printing mask 55 was fixed to the screen frame 51, and the screen mesh inside the fixed was cut off (c). A reinforcing tape 513 is applied to the screen mesh portion around the printing mask, and an adhesive is applied to the back surface to which the tape is applied to reinforce, thereby obtaining a printing mask frame assembly 516 (d). The tension on the printing mask surface of the printed mask frame assembly after completion was measured with a tension gauge (MTG-08A manufactured by Protec Co., Ltd., hereinafter referred to as “tension gauge 2”). The direction was 1.05 mm, the Y direction was 0.7 mm, and the tension ratio X: Y was 1: 1.5. Here, in the present invention, the tension gauge 2 was placed near the center of the printing mask surface of the printing mask frame assembly to measure the tension. When the fine line-shaped opening dimension of this printing mask frame assembly was measured, it was confirmed that the maximum change amount of the fine line-shaped opening dimension due to the tension was 0.007 mm.

A printing test was conducted using the printing mask frame assembly thus produced. In this test, a silver paste was printed on a silicon wafer having a size of 160 mm × 160 mm using a metal squeegee of a hand-printed printing press. Here, the printing direction was performed so as to be parallel to the longitudinal direction of the fine line-shaped opening. As a result, a good print result with a rectangular cross-section was obtained without cracking or chipping of fine print lines of the silver paste due to insufficient filling. In magnified observation, it was confirmed that the surface was flat without irregularities.
When the width of the paste fine line printed in the printed pattern was measured, it was confirmed that the difference in the width was 0.010 mm at the maximum. Moreover, most of the cross-section of the paste thin line was rectangular, and no bleeding of the skirt was observed. Here, the measurement and observation of the paste fine line were performed in the vicinity of the center as shown in FIG.

[Example 2]
A printing mask frame combined body is formed by fixing a printing mask in which a broken-line tension buffer opening is formed by the same manufacturing method as in Example 1 to the screen frame having the same specifications as those used in Example 1. Produced. Here, the printing mask in this example is the same as that in Example 1 except that the interval in the X ′ direction of the broken line is 0.5 mm.
When the size of the fine line-shaped opening of the mask frame assembly for printing was measured, the maximum value of the change amount of the fine line-shaped opening due to the stretching was 0.007 mm.

Example 3
Furthermore, a printing mask frame assembly similar to the above was produced using a printing mask having the same specifications as in Example 1 except that the distance in the X ′ direction of the broken line was 0.2 mm. The maximum value of the change amount of the fine line-shaped opening was 0.003 mm. From this, it can be seen that the tension buffering effect is increased by reducing the interval between the broken lines.

Example 4
Next, when a printing mask frame assembly similar to that of Example 1 was prepared except that the distance between the printing pattern and the tension buffering opening was set to 20 mm, the maximum value of the fine line-shaped opening dimensions by stretching was as follows. It was 0.003 mm.

Example 5
Further, when a printing mask frame assembly similar to that of Example 1 was prepared except that the distance between the printing pattern and the tension buffering opening was 30 mm, the maximum value of the fine line-shaped opening dimensions by stretching was 0. 0.002 mm.

Example 6
In the printing mask of Example 1, the distance between the printing pattern and the tension buffer opening was 30 mm, the number of broken lines was increased from three to five, and the interval in the X ′ direction between the broken lines was 0.5 mm. Using the printing mask, a printing mask frame assembly similar to that of Example 1 was produced. The maximum value of the amount of change in the roller fine line opening was 0.006 mm.

Example 7
In the printing mask of Example 1, the distance between the printing pattern and the tension buffering opening is set to 30 mm, the interval in the X ′ direction between the broken lines is set to 0.5 mm, and the length in the Y ′ direction of the small opening of the broken line is set. When a printing mask frame assembly similar to that of Example 1 was produced using a printing mask having a thickness of 20 mm, the maximum amount of change in the fine line-shaped opening was 0.003 mm.

Example 8
In the printing mask of Example 1, the tension buffer opening was formed into a slit shape as shown in FIG. Here, the width of the opening was 1 mm, the length was 155 mm, and the distance in the X ′ direction from the print pattern was 10 mm. When this printing mask was used to produce a printing mask frame assembly similar to that in Example 1, the maximum value of the change amount of the fine line-shaped opening was 0.010 mm.

Example 9
A printing mask frame assembly similar to that in Example 8 was produced using this printing mask in the same printing mask as in Example 8 except that the opening width was 10 mm. The maximum value of the amount of change in the part was 0.010 mm.

[Comparative Example 1]
A mask frame assembly for printing similar to that of Example 1 was prepared except that the positions of the upper and lower ends of the arrangement of broken lines as the tension buffering openings were aligned. At this time, the maximum value of the change amount of the fine line-shaped opening due to the tension was 0.020 mm.

[Comparative Example 2]
A printing mask frame assembly similar to that of Example 1 was manufactured by setting the distance between the printing pattern and the tension buffer opening to 1 mm. At this time, the maximum value of the change amount of the fine line-shaped opening due to the tension was 0.035 mm.

[Comparative Example 3]
A printing mask frame assembly similar to that in Example 8 was produced using this printing mask in the same printing mask as in Example 8 except that the opening width was 15 mm. The maximum value of the amount of change in the part was 0.030 mm. At this time, the shape of the printing mask was unstable, and distortion occurred when the printing mask was fixed to the screen.

[Comparative Example 4]
Using the same screen mesh frame as in Example 1, a printing mask frame assembly was produced. The printing mask frame assembly is the same specification as the printing mask of Example 1, ie, an anisotropic tension mask plate, except that the tension buffer opening and the printing mask holding spacer are not provided. .
It was confirmed that the maximum value of the change amount of the fine line-shaped opening due to the tensioning was larger than Example 1 and 0.040 mm because there was no opening for tension buffering.

Using this printing mask frame assembly, the same printing test as in Example 1 was performed. As a result, the same good results as in Example 1 were obtained with respect to the filling of the silver paste and the cross-sectional shape of the printed fine lines. However, when the width of the paste fine lines printed in the printed pattern was measured, The maximum difference between the width of the thin wire and the width of the inner thin wire was 0.040 mm.
The printing direction was performed so as to be parallel to the longitudinal direction of the fine line-shaped opening. In addition, the paste thin line at the end of the printed pattern was blurred at the bottom due to the gap generated in the printing mask and the wafer.

[Comparative Example 5]
Using the same screen mesh frame as that of Example 1, a mask frame assembly for printing was produced on the screen mesh frame. The printing mask frame assembly is the same as that of Example 1 except that it does not have a printing mask holding spacer. As a result of the same printing test as in Example 1 using this printing mask frame assembly, the fine paste lines at the edges of the printing pattern showed bleeding at the bottom due to the gaps formed in the printing mask and wafer. It was.

[Comparative Example 6]
A printing mask frame assembly having a tension anisotropy of X: Y = 1: 1.1 was produced with the same specifications as in Example 1. At this time, this printed mask frame assembly had a remarkable change in the size of the fine line-shaped opening, which was 0.050 mm at the maximum, and the electrode shape defect was confirmed. Similarly, in the case of 1: 1.2, the results in the case of 1: 1.3, 1: 1.5, 1: 2.3, 1: 2.5 are shown in the table of FIG.

11 59 Print pattern 12 13 14 56 57 58 Thin line opening 15 Print pattern end 16 Print pattern inside 17 510 Tension buffer opening 21 Length of small opening in Y ′ direction 22 Distance between small openings in Y ′ direction 23 Interval between X'-directions of tension buffer openings 31 Squeegee 32 Printing mask 33 Substrate 34 Printing stand 35 Printing mask holding spacer 36 Paste thin line 37 with bleeding at the skirt 37 Pasting thin line 41 without bleeding 41 Printing mask 42 Adhesive 43 Board (spacer)
44 Plating film 45 Plating film (spacer)
46 Tape (Spacer)
51 Screen frame 52 Frame 53 Screen mesh 54 514 Tension (measured value)
55 Print Mask 511 Distance 512 between Print Pattern and Tension Buffering Opening 512 Combination 513 Reinforcement Tape 515 Tape (Spacer)
516 Mask Frame Combined Body for Printing 61 Measurement section for width of paste fine line

Claims (16)

A printing mask having a fine line-shaped opening with a ratio of the length in the short-side direction and the lengthwise direction of 1:10 or more,
A printing mask, wherein an opening for tension buffering is provided outside a region of a printing pattern. 2. The printing mask according to claim 1, wherein two or more openings for buffering tension are arranged in a broken line shape in the longitudinal direction of the fine line opening. When two or more openings for buffering the tension are arranged in a broken line shape in the longitudinal direction of the thin line-shaped opening, the upper and lower ends thereof are arranged in a staggered manner. Item 3. A printing mask according to Item 2. The printing mask according to claim 2, wherein an interval in the X ′ direction for the tension buffering in the broken line shape is 0.05 mm or more and 5.0 mm or less. The printing mask according to any one of claims 2 to 4, wherein an interval in a Y 'direction between small openings constituting the broken-line tension buffering opening is 1 mm or more and 10 mm or less. 6. The printing mask according to claim 2, wherein a length of a small opening constituting the broken-line tension buffering opening in the Y ′ direction is 5 mm or more and 30 mm or less. The printing mask according to claim 1, wherein a length in the X ′ direction of the tension buffering opening is 0.05 mm or more and 10 mm or less. The printing mask according to claim 1, wherein the tension buffer opening and the printing pattern are separated by 10 mm or more in the X ′ direction. The length of the tension buffer opening in the Y ′ direction is not less than 0.5 times and not more than 1.5 times the length of a side of an adjacent print pattern. The mask for printing described. 10. The printing mask according to claim 1, wherein a spacer for holding the printing mask is provided in an area outside the printing pattern on the surface of the printing mask that contacts the substrate. A method for producing a printing mask frame assembly in which a printing mask is stretched on a screen frame via a screen mesh,
Stretching the screen mesh in a state where the ratio of the tension in the X direction and the Y direction is 1: 1.5 or more and 1: 2.8 or less in the frame;
The step of adhering the periphery of the printing mask to the screen mesh in a state where the longitudinal direction of the fine line-shaped opening of the printing mask is substantially the Y direction. ,
Cutting the screen mesh of the inner part of the printing mask fixing part;
A method for producing a combined mask frame for printing, comprising: A printing mask in which the printing mask according to any one of claims 1 to 10 is stretched on a screen frame via a screen mesh in a state where the longitudinal direction of the fine line-shaped opening of the printing mask is substantially in the Y direction. A frame combination,
The printing mask frame assembly, wherein the ratio of tension in the X direction and the Y direction in the printing mask is from 1: 1.3 to 1: 2.3. A method for producing a printing mask frame assembly in which a printing mask is stretched on a screen frame via a screen mesh,
Stretching the screen mesh in a state where the ratio of the tension in the X direction and the Y direction is 1: 1.5 or more and 1: 2.8 or less in the frame;
A step of fixing the periphery of the printing mask to the screen mesh in a state in which the longitudinal direction of the fine line-shaped opening of the printing mask is substantially the Y direction. ,
Cutting the screen mesh of the inner part of the printing mask fixing part;
A step of providing a spacer for holding the printing mask on the substrate contact surface of the printing mask;
A method for producing a combined mask frame for printing, comprising: A printing mask frame assembly in which the printing mask according to any one of claims 1 to 9 is stretched on a screen frame through a screen mesh in a state where the longitudinal direction of the fine line-shaped opening is substantially in the Y direction. And
The ratio of the tension in the X direction and the Y direction in the printing mask is 1: 1.3 or more and 1: 2.3 or less, and the printing mask is held in a region other than the substrate contacting portion of the substrate contacting surface of the printing mask. A mask frame assembly for printing, wherein a spacer for printing is provided. 15. The printing mask frame assembly according to claim 12, wherein the printing mask frame assembly is for manufacturing an electrode of a substrate for a solar cell. A solar battery cell produced using the printing mask frame assembly according to claim 15.