TWI643023B - Mesh member for screen printing and screen printing plate - Google Patents

Abstract

Provided is a screen printing screen that has an opening portion formed by etching in a rolled metal foil used for a screen printing plate with high robustness, which is less likely to be affected by external disturbances to printing conditions during printing. member.

The mesh member for screen printing is a mesh member for screen printing formed of metal foil. A plurality of openings are arranged along one direction. The longitudinal direction is the aforementioned one direction and spans the plurality of openings. The direction in which the directions intersect has a line pattern with a width W in a range of 10 μm to 60 μm. The standard deviation of the area of the plurality of openings in the line pattern is in a range of 3.8 W (μm ² ) or more (20W + 10) (μm ² ) or less. .

Description

Mesh member for screen printing and screen printing plate

The present invention relates to a screen member for screen printing and a screen printing plate using the screen member for screen printing.

Screen members are now widely used for printing finger electrodes for solar cells. In the screen printing plate using the screen member, a screen member in which a stainless steel wire having a wire diameter of 16 μm to 20 μm is knitted into a yarn is probably used. Therefore, in a screen printing plate, there exists a crossing part of a screen. As a result, there is a problem that the height difference between the so-called printed finger lines is large. In addition, when the plate is peeled off, there is a problem that the paste remains on the screen, that is, the paste is badly peeled off. Furthermore, with regard to repeated printing, problems such as deterioration in position accuracy may occur due to slackness of the screen member.

In addition, when a high-viscosity paste is used for the purpose of thinning, the transferability is poor, that is, the paste has poor web permeability, and problems such as the plugging of the paste in the mesh and causing disconnection may occur.

In addition, if the emulsion opening width is a thin line area of about 30 μm, the finger lines will be scratched after printing, that is, the problem that the paste is not sufficiently transferred to the object to be printed cannot be achieved. Fine line printing.

On the other hand, the screen member refers to a screen technique (for example, refer to Patent Document 1) which is a technique for making holes in a rolled metal foil by etching as another technique.

[Prior technical literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2011-194885

[Patent Document 2] Japanese Patent Publication

Even if a screen is opened by etching in the rolled metal foil, it is equivalent to or more than a screen member, and it is necessary that the printing characteristics are not easily affected by external disturbances to printing conditions, that is, high robustness is required.

The present invention provides a screen member for screen printing, in which printing characteristics are not easily affected by external disturbances to printing conditions during printing, that is, a screen member is provided with an opening in a metal foil for a screen printing plate with high robustness. As purpose.

The mesh member for screen printing of the present invention is a mesh member for screen printing made of metal foil, wherein a plurality of openings are arranged along one direction, and the long side direction is the aforementioned one direction and spans the aforementioned plurality. The standard deviation of the area of the plurality of openings in the opening pattern with respect to a line pattern defined by two straight lines separated by a width W of a range of 10 μm to 60 μm in a direction that intersects the aforementioned one direction. It is in a range of 3.8W (μm ² ) or more (20W + 10) (μm ² ) or less.

According to the screen member for screen printing according to the present invention, the screen member is equal to or more than the screen member, and the external interference printing characteristics with respect to printing conditions are not easily affected, that is, a screen printing plate with high robustness can be obtained.

2‧‧‧Patterns for finger electrodes

4‧‧‧ pattern for bus electrode

10, 10a, 10b ‧‧‧ Mesh members for screen printing

12‧‧‧ opening (hole (oval))

14‧‧‧ opening (hole (rectangular))

16‧‧‧Resin (photosensitive emulsion)

17a, 17b‧‧‧imaginary line

18‧‧‧ line pattern

20‧‧‧ Screen printing

22‧‧‧ aluminum frame

24‧‧‧ Mesh Fabric

32‧‧‧ opening

34‧‧‧ opening

36‧‧‧Resin (photosensitive emulsion)

38‧‧‧ line pattern

40a, 40b ‧‧‧ Mesh members for screen printing

42‧‧‧Scraper

43‧‧‧ plaster

44‧‧‧Scraper

46‧‧‧Printing objects

47‧‧‧Scraped surface

48‧‧‧print side

50‧‧‧ Screen printing

51‧‧‧Wire

52‧‧‧ opening

53‧‧‧ line pattern

56‧‧‧ resin (photosensitive emulsion)

58‧‧‧ line pattern

[Fig. 1] A plan view showing an outline of a screen member for screen printing according to the first embodiment.

FIG. 2A is an enlarged plan view showing a plurality of elliptical openings arranged in one direction with respect to the pattern for finger electrodes of the screen-like mesh member in FIG. 1.

FIG. 2B is an enlarged plan view showing a plurality of rectangular openings arranged in one direction with respect to the pattern for finger electrodes of the mesh member for screen printing of FIG. 1.

3A is a plan view showing an outline of the screen printing plate according to the first embodiment.

[Fig. 3B] Fig. 3B shows an end face structure viewed from the A-A direction of Fig. 3A. End view.

FIG. 4A shows a plurality of oval openings arranged along one direction with respect to the pattern for finger electrodes of the screen printing plate of FIG. 3A as viewed from the printed surface of the line pattern caused by the photosensitive emulsion. Magnified top view.

4B is a view showing a plurality of rectangular openings arranged along one direction with respect to the pattern for finger electrodes of the screen printing plate of FIG. 3A as viewed from the printed surface of the line pattern caused by the photosensitive emulsion; Magnified top view.

5 A plan view showing an outline of a screen printing plate using a conventional screen member.

[Fig. 6] (a) to (e) are printing plates using the screen member of Fig. 5, and the width W is 20 μm (a), 25 μm (b), and 30 μm (c) when viewed from the printing surface side. , 35 μm (d), and 40 μm (e).

7A is an enlarged plan view showing a plurality of elliptical openings arranged along one direction with respect to a pattern for finger electrodes of a screen-shaped mesh member formed of a rolled metal foil.

7B is an enlarged plan view showing a plurality of rectangular openings arranged along one direction with respect to a pattern for finger electrodes of a screen-shaped mesh member formed of a rolled metal foil.

FIG. 8A shows a pattern for finger electrodes of a screen printing plate using the screen member for screen printing of FIG. 7A, as seen from the printed surface of the line pattern caused by the photosensitive emulsion, along one direction. An enlarged plan view of a plurality of oval openings arranged.

[Fig. 8B] Fig. 8B shows a screen structure for screen printing using Fig. 7B. An enlarged plan view of a plurality of rectangular openings arranged along one direction from the printed surface of the finger electrode pattern of the screen printing plate of the present invention, as viewed from the printed surface of the line pattern by the photosensitive emulsion.

[FIG. 9] A schematic diagram showing an outline of a screen printing plate.

[Fig. 10A] A histogram of the area of the openings between the wires exposed in a line pattern with a width of 25 [mu] m in Fig. 6 (b).

[FIG. 10B] A histogram of the area of the openings between the wires exposed in the 30 μm-wide line pattern of FIG. 6 (c).

[FIG. 10C] A histogram of the area of the openings between the wires exposed in the 35 μm-wide line pattern in FIG. 6 (d).

[FIG. 10D] A histogram of the area of the openings between the wires exposed in the 40 μm-wide line pattern in FIG. 6 (c).

[Fig. 11] The printing plate using the screen member of Figs. 6 (a) to (e) and the printing plate of the screen member for screen printing formed by the metal foil of Fig. 8B are shown with the width of the line pattern and Graph showing the relationship between the average area of the openings in the line pattern.

[Fig. 12] The width of the line pattern and the line are shown for the printing plate using the screen member of Figs. 6 (a) to (e) and the printing plate of the screen member for screen printing formed by the metal foil of Fig. 8B. A graph of the relationship between the standard deviation of the area of the openings in the pattern.

In the first aspect, the mesh member for screen printing is formed by a metal foil, and the mesh member for screen printing includes a plurality of openings arranged along one direction, and the long side direction is the aforementioned one direction and crosses the aforementioned direction. For the plurality of openings, a line pattern defined by two straight lines separated by a width W of a range of 10 μm to 60 μm in a direction intersecting the one direction, and the area of the plurality of openings in the line pattern is The standard deviation is in a range of 3.8 W (μm ² ) or more (20W + 10) (μm ² ) or less.

In the second aspect of the screen member for screen printing, in the first aspect, the average value of the area of the openings in the line pattern may be in a range of 700 to 2000 μm ² .

In the third aspect, the mesh member for screen printing, in the first or second aspect, the thickness of the metal foil may be 5 μm or more and 30 μm or less.

In a fourth aspect, the mesh member for screen printing, in any one of the first to third aspects, the metal foil includes: stainless steel, titanium, a titanium alloy, nickel, a nickel alloy, copper, At least one selected from the group of copper alloy and aluminum alloy may be used.

The screen printing plate of the fifth aspect is provided with the screen member for screen printing of any one of the first to fourth aspects, and covering the plurality of openings arranged along the one direction. And a plurality of openings are provided in the one direction in the longitudinal direction and across the plurality of openings, and the direction intersecting the one direction is separated by two straight lines separated by a width W in a range of 10 μm to 60 μm. The resin opening is divided into a line pattern.

<About the principle of achieving this invention>

First, the present inventor used a screen printing plate of a screen printing mesh member having a plurality of openings in a rolled metal foil to find a problem that the external interference with printing conditions is weak. On the other hand, the present inventors have found out why the external interference with printing conditions in a screen printing plate using a conventional screen member is less likely to be affected by printability.

Here, the present inventors have made a detailed comparison between a screen printing mesh member having a plurality of openings in a rolled metal foil and a silk screen member that is currently in mass production. analysis. Thereby, the reason why the screen printing plate of the screen printing screen-like member provided with many openings in a rolled metal foil is weak against external disturbance of printing conditions is found. On the other hand, the reason why a screen printing plate using a screen member is less likely to be affected by printability (high robustness) due to external disturbances to printing conditions.

The inventors have found out that the unevenness of the area of the openings exposed in the line pattern regardless of the width of the line pattern (emulsion opening width) of the screen printing plate provided with a plurality of openings in the rolled metal foil will be described later. (Standard deviation) When it is less than 150 μm ² . On the other hand, the standard deviation of the area of the opening of the screen printing plate using a screen member was found to be very large at 450 μm ² or more.

That is, the reason why the mesh member for screen printing for which openings are made in the rolled metal foil is easily affected by external disturbance of printing conditions is conceivable because the standard deviation due to the opening area is extremely small. On the other hand, in a screen printing plate using a screen member, it is conceivable that the standard deviation of the opening area The difference is very large, so it has openings of various areas, and it is also susceptible to changes in printing conditions, and it is easy to reproduce the same printing characteristics.

Furthermore, it can be understood that the screen member is likely to cause the clogging of the paste, especially in the thin line region, for repeated printing.

The inventors have found that, as will be described later, a screen printing plate using a screen member has a distribution of a small area having an area of 600 μm ² or less across the opening. In this way, it is conceivable that the area of the opening is less than 600 μm ² , because the paste cannot pass well, so the blockage of the opening between the wires 51 is not only not helpful for printing, but also induces the net at the mass production site. The increase in the number of plate cleaning times increases the number of stoppages of the printing device, which causes problems such as a reduction in throughput.

Based on these findings, by improving the mesh structure for screen printing, which has openings in rolled metal foil, it is possible to obtain a mesh member for screen printing that is not easily affected by external disturbances to printing conditions, and use the same. The present invention is achieved by a screen printing plate for a screen-shaped member for screen printing.

Specifically, the screen member for screen printing of the present invention has a certain area distribution with respect to the plurality of openings exposed by the line pattern. Specifically, the standard deviation of the areas of the plurality of openings in the line pattern is in a range of 3.8 W (μm ² ) or more (20W + 10) (μm ² ) or less.

Thereby, external disturbances in printing conditions such as changes in printing characteristics with respect to changes in viscosity time of the paste are less likely to be affected, that is, a screen printing plate having high robustness can be realized.

Hereinafter, the screen-shaped member for screen printing using the embodiment and the screen-shaped member for screen printing using the embodiment will be described with reference to the accompanying drawings. Screen printing. In addition, the same symbols are assigned to substantially the same components in the drawings.

(Embodiment 1)

<Mesh member for screen printing>

FIG. 1 is a plan view showing the outline of a screen member 10 for screen printing according to the first embodiment. FIG. 2A is an enlarged plan view showing a plurality of elliptical openings 12 arranged in one direction with respect to the finger electrode pattern 2 of the screen member 10 for screen printing of FIG. 1. 2B is an enlarged plan view showing a plurality of rectangular openings 14 arranged in one direction with respect to the pattern for finger electrodes of the mesh member for screen printing of FIG. 1. In addition, the openings 12 and 14 in the drawing are merely examples, and the dimensional ratios and the like do not indicate actual states.

The screen member 10 for screen printing according to the first embodiment is formed of a metal foil. The screen member 10 for screen printing has a plurality of openings 12 and 14 arranged along one direction. Furthermore, the two imaginary straight lines 17a, 17b are drawn with the long-side direction being the above-mentioned direction and separated by a width W of a range of 10 μm to 60 μm across the plurality of openings 12 and 14 in a direction intersecting the above-mentioned direction. . In a line pattern 18 divided by two straight lines 17a and 17b, the standard deviation of the area of the plurality of openings 12, 14 in the line pattern 18 is 3.8 W (μm ² ) or more (20W + 10) (μm ² ) The following range.

According to the screen member 10 for screen printing, the standard deviation of the areas of the plurality of openings 12 and 14 in the line pattern 18 is within the above range, The areas of the plurality of openings 12 and 14 have a certain degree of distribution. Here, when it is used for a screen printing plate, external disturbances in printing conditions such as a change in the viscosity of the paste over time during printing are generated, and a change in the most suitable area range of the plurality of openings 12 and 14 occurs. Because the areas of the openings 12 and 14 have a distribution, it can correspond to the most suitable area range after the change. Therefore, according to the screen member 10 for screen printing, the printing characteristics are not easily affected by external disturbances in the printing conditions, that is, high robustness can be obtained.

Hereinafter, each member constituting the screen member 10 for screen printing will be described.

<Metal foil>

The metal foil is a rolled metal foil. In addition, it is not limited to a rolled metal foil, but may be a metal foil by electroforming. The metal foil may include, for example, at least one selected from the group consisting of stainless steel, titanium, titanium alloy, nickel, nickel alloy, copper, copper alloy, and aluminum alloy.

The thickness of the metal foil may be 5 μm or more and 30 μm or less.

In addition, many openings provided in the metal foil may be formed by chemical etching, mechanical opening processing, or electroforming.

<Pattern for finger electrode>

As shown in FIGS. 2A and 2B, the finger electrode pattern 2 has openings 12 and 14 arranged along one direction. Since it is arranged in one direction in this way, as long as the imaginary two are arranged with a width W along the above direction The straight lines 17a and 17b can be divided into a line pattern 18 across a plurality of openings 12, 14. This line pattern 18 corresponds to a line pattern for finger electrodes in a screen printing plate described later. The planar shapes of the openings 12 and 14 are not limited to the oval shape shown in FIG. 2A and the rectangular shape shown in FIG. 2B, and may have other shapes.

In addition, the width W of the imaginary two straight lines 17a and 17b corresponds to the width of the finger electrode to be formed, and is, for example, in a range of 10 μm to 60 μm.

The standard deviation of the areas of the plurality of openings 12 and 14 in the line pattern 18 is 3.8 W (μm ² ) or more, and is within a range of (20 W + 10) (μm ² ) or less. The derivation of the above formula will be described later. The lower limit of 3.8 W (μm ² ) represents 3.8 times the width W of the line pattern 18. In FIG. 12, the area is higher than a straight line using the connecting symbol ■ and the symbol ▲. The lower limit of 3.8 W corresponds to the standard deviation of the area of the openings after actual measurement of the openings in the line pattern of the screen printing plate when the size of the plurality of openings 12 and 14 is constant. In addition, there is no theoretical distribution when the area is constant, and the standard deviation is zero. That is, even in the case of the above-mentioned lower limit, the openings 12 and 14 have a slight distribution. The upper limit (20W + 10) (μm ² ) is a value that is 20 times the width W of the line pattern 18 plus a 10 μm slice. In FIG. 12, the area is lower than the straight line using the connecting symbol ◆. This upper limit (20W + 10) (μm ² ) corresponds to the standard deviation of the area of the openings after actual measurement of the openings in the line pattern of the screen printing plate using a screen member described later. That is, the screen member 10 for screen printing includes a plurality of openings 12 and 14 from a case where there is a distribution slightly more than a case where the area is constant to a case where the area distribution is the same as that of the screen member. Thereby, even if the external interference of printing conditions such as a change in the viscosity of the paste over time occurs and the optimum area range of the plurality of openings 12 and 14 is changed, the area of the openings 12 and 14 has a certain degree. Distribution, and can correspond to the most suitable area range after the change. Here, stable printing characteristics can be obtained regardless of the presence or absence of external disturbances in printing conditions.

For example, in FIG. 2A and FIG. 2B, the case where the area of the several opening parts 12 and 14 is not necessarily a certain distribution is illustrated. In FIGS. 2A and 2B, a plurality of openings 12 and 14 having different areas are arbitrarily arranged. The plurality of openings 12 and 14 have the above-mentioned standard deviation in the area distribution by changing the size. In addition, this is merely an example for showing that the areas of the openings 12 and 14 have a certain degree of distribution. In FIGS. 2A and 2B, the standard deviations of the areas of the openings 12 and 14 do not satisfy the above range. In addition, the arrangement of the openings 12 and 14 having various areas in one direction is also exemplified, that is, the arrangement is not limited to an arbitrary arrangement, and for example, it may be arranged periodically with a change in area.

The width W of the line pattern 18 is 10 μm to 60 μm, and the average value of the areas of the openings 12 and 14 in the line pattern 18 is in the range of 700 to 2000 μm ² . The average value of the areas of the openings 12 and 14 may be appropriately changed depending on the width W of the line pattern 18. For example, as shown in FIGS. 2A and 2B, the openings 12 and 14 are extended to extend along the width direction of the line pattern 18. The area exposed in the line pattern 18 of the openings 12 and 14 is proportional to the width W of the line pattern 18. Make changes.

<Manufacturing method of screen member for screen printing>

The openings 12 and 14 can be formed by etching from one or both sides of the metal foil. It is only necessary to perform appropriate etching in accordance with the desired shape and area of the openings 12 and 14 and the distribution thereof. For example, a metal foil is coated with a photoresist, a plurality of openings are arranged in a desired size and arrangement, and development is performed after exposure using a mask on which a printed pattern is drawn. Thereafter, the metal foil in the portion where the opening portion is opened is melted by etching, so that the screen-shaped mesh member 10 for the metal foil opening portion 12 or 14 can be produced.

Moreover, the manufacturing method of the mesh member for screen printing does not limit the manufacturing method to the etching of metal foil, For example, the manufacturing method by mechanical opening processing and electroforming can also be implemented.

<Screen printing plate>

FIG. 3A is a plan view showing an outline of the screen printing plate 20 according to the first embodiment. Fig. 3B is an end view showing the structure of the end face of the screen printing plate 20 as viewed from the direction A-A in Fig. 3A. FIG. 4A shows a plurality of elliptical shapes arranged along one direction with respect to the pattern for finger electrodes of the screen printing plate 20 of FIG. 3A as viewed from the printing surface of the line pattern 18 provided with the photosensitive emulsion 16. An enlarged plan view of the opening portion 12. FIG. 4B shows a plurality of rectangles arranged along one direction with respect to the pattern for the finger electrode of the screen printing plate 20 of FIG. 3A as viewed from the printing surface of the line pattern 18 formed by the resin 16 caused by the photosensitive emulsion. An enlarged plan view of the shaped opening portion 14.

This screen printing plate 20 is, as shown in FIGS. 3A and 3B, the mesh member 10 for screen printing described above is arranged with a mesh fabric 24 of polyester fine threads woven in an aluminum frame 22 and the like. The screen printing plate 20 has: The mesh member for lithographic printing, the resin 16 covering a plurality of openings 12 and 14 arranged along one direction, and two straight lines separated by a width W separated by a range W of 10 μm to 60 μm in which the resin 16 opens. Is divided into line patterns 18. The above-mentioned line pattern 18 has a long-side direction and is provided across the plurality of openings 12 and 14. The width W is a direction crossing the longitudinal direction. The width W is a direction that intersects the longitudinal direction at an angle, for example. Alternatively, the width W may be a direction perpendicular to the longitudinal direction.

As shown in FIG. 9, the screen printing plate 20 includes a printing surface 48 provided with a line pattern 18 defined by the opening of the resin 16, and a squeegee 42 for applying a paste 43 printed by pattern printing.的 滑 涂 面 47。 The scraped surface 47.

According to this screen printing plate 20, the above-mentioned screen member 10 for screen printing is used. Here, in the line pattern 18 defined by the opening of the resin 16 by two straight lines separated by the width W, the standard deviation of the area of the plurality of openings 12 and 14 in the line pattern 18 is 3.8 W (μm ² ) Above (20W + 10) (μm ² ) or less.

In addition, the area distribution of the openings 12 and 14 is related to the plurality of openings 12 and 14 in the line pattern 18 on the side of the coating surface 47. At this time, the resin 16 from the printing surface 48 reaches the blade coating surface 47 and fills the openings 12 and 14 other than the line pattern 18.

Therefore, even during printing, external disturbances in printing conditions such as changes in the viscosity of the paste over time occur, and when the most suitable area range of the plurality of openings 12, 14 is changed, the openings 12, 14 The area has a distribution, and can correspond to the most suitable area range after the change. Therefore, according to the screen member 10 for screen printing, the printing characteristics are not easily affected by external disturbances in the printing conditions, that is, high robustness can be obtained.

Hereinafter, each member constituting the screen printing plate 20 will be described.

<Mesh member for screen printing>

Since the mesh member for screen printing uses the above-mentioned mesh member 10 for screen printing, the description is omitted.

<Resin>

As shown in FIGS. 4A and 4B, the resin 16 covers a plurality of openings 12 and 14 arranged along one direction.

This resin 16 is obtained by photocuring a photosensitive emulsion.

<Line pattern>

The line pattern 18 is divided by opening two resins 16 with two straight lines separated by a width W. The line pattern 18 has a longitudinal direction in one direction, and is provided across the plurality of openings 12 and 14. The width W is a direction crossing the longitudinal direction.

<Method for Manufacturing Screen Printing Plate>

The screen printing plate 20 can be produced as follows. For example, in metal After the entire surface of the foil is coated with the resin (photosensitive emulsion), the portion corresponding to the opening line pattern is covered with a mask, and the area covered with the mask is exposed to light. The resin (photosensitive emulsion) in the area after exposure is cured, and the resin (photosensitive emulsion) in the opening portion of the place covered with the mask is removed, and the screen printing plate 20 can be manufactured. In addition, the above-mentioned production method is an example and is not limited by this.

<About screen printing plate>

FIG. 9 is a schematic diagram showing an outline of a screen printing plate.

During printing, the squeegee surface 47 of the screen printing plate is taken as the vertical upper surface, and the printing surface 48 is taken as the vertical lower surface. The printing surface 48 is opposed to the printing target 46 to be screen-printed. On the other hand, the paste 43 is placed on the doctor blade surface and the blade 42 is moved from left to right in FIG. 9 to fill the openings (holes) 12 and 14 in the line pattern 18 (see FIGS. 4A and 4B). The paste 43 is made to adhere to the printing object 46. After the squeegee 42 passes, the screen printing plate is separated from the printing target 46 by the tension of the screen printing plate. On the other hand, the paste 43 remains on the printing target 46. Thereby, screen printing is performed, and the paste 43 corresponding to the arrangement of the openings 12 and 14 exposed by the line pattern 18 is printed. Thereafter, the paste 43 having unevenness, which is derived from the openings 12 and 14, is subjected to a leveling step to form a finger electrode.

<About role. Effect>

The effect of the screen printing plate of the first embodiment. Effect The screen printing plate 50 of the conventional screen member and the screen printing plate using the screen printing mesh members 40a and 40b provided with a certain size opening in a rolled metal foil will be described.

<About past wire mesh members>

FIG. 5 shows a schematic plan view of a screen printing plate 50 using a conventional screen member.

As shown in FIG. 5, a screen printing plate 50 using a conventional screen member is a screen member in which a wire 51 made of metal or resin (for example, polyester) is knitted. The screen printing plate 50 is a mesh fabric in which polyester thin threads are woven and bonded to the periphery of the screen member in the same manner as in the case of FIG. 3A, and is further fixed to an aluminum frame. The screen printing plate 50 using a screen member is covered with a resin 56 and the resin 56 is opened to form a line pattern 53 for finger electrodes. In the line pattern 53, the openings 52 between the wires 51 are exposed.

<Line pattern in screen printing plate using screen member>

Figs. 6 (a) to 6 (e) are screen printing plates 50 using the screen member (# 360-Φ16CL) of Fig. 5. When viewed from the printing surface side, the width W is 20 μm (a), 25 m (b), 30 m (c), 35 m (d), and 40 m (e) of the opening pattern 52 between the wires 51 exposed by the line pattern 58 is schematically shown. The width W is the width of the line pattern 58 (the width of the emulsion opening portion). In addition, FIG. 6 shows a line pattern length of 1.8 mm.

In FIG. 6, the screen member is slanted by 22.5 ° with respect to the longitudinal direction of the line pattern 58, that is, a skew is applied to perform screen printing. So not giving When the screen member is deflected, that is, when the screen member is not tilted, when the width W of the line pattern 58 is narrow, the wire material 51 may be cut by cutting the line pattern 58 vertically. At this time, the line pattern 58 is blocked by the wire 51 and the opening cannot be printed reliably. Therefore, it is common that the screen member is plated (coated with an emulsion) with the long side direction of the line pattern 58 being inclined by 22.5 °.

In the screen printing plate 50 using a screen member, the screen member is inclined by 22.5 ° with respect to the longitudinal direction of the line pattern 58. Here, as shown in FIGS. 6 (a) to 6 (e), the shapes of the openings between the wires 51 exposed by the wire patterns 58 are various, and it can be understood that the opening area is disordered. Further, as the width of the line pattern (emulsion opening width) is reduced from the width w40 to the width w20, it can be seen that the area of the openings between the wire materials 51 becomes smaller.

FIG. 10A is a histogram of the area of the openings between the wire members 51 exposed by the line pattern 58 having a width of 25 μm in FIG. 6 (b). FIG. 10B is a histogram of the area of the openings between the wire members 51 exposed by the line pattern 58 having a width of 30 μm in FIG. 6 (c). FIG. 10C is a histogram of the area of the openings between the wire members 51 exposed by the 35 μm-wide line pattern 58 in FIG. 6 (d). FIG. 10D is a histogram of the area of the openings between the wire members 51 exposed by the 40 μm-wide line pattern 58 in FIG. 6 (e). In addition, FIGS. 10A to 10D show the areas of the openings between the wire members 51 existing in the 1.8 mm wire pattern 58. It should be noted that the area is not the entire opening portion between the wires 51 but an area formed by the opening portion and the wall of the resin 56.

When the width W of the line pattern 58 is 40 μm, as shown in FIG. 10D, the areas of the openings between the wires 51 exposed by the line pattern 58 are almost evenly distributed between 100 and 2300 μm ² .

When the width of the line pattern 58 is W 35 μm, as shown in FIG. 10C, the area of the opening portion between the wires 51 exposed by the line pattern 58 is a frequency with a slightly larger opening area of 1800 to 2100 μm ² , and there is no offset It is distributed between 100 and 2100 μm ² .

On the other hand, as the width W of the line pattern 58 becomes narrower, as shown in FIGS. 10A and 10B, it can be seen that the maximum value of the area of the opening portion between the wire materials 51 exposed by the line pattern 58 becomes smaller.

From the data of FIGS. 10A to 10D, the average value of the distribution of the width W of the line pattern 58 and the area distribution of the openings between the wire materials 51 exposed by the line pattern 58 in the screen printing plate 50 using a screen member is compared to The relationship between the area unevenness (standard deviation σ) is summarized in Table 1. The standard deviation also has about 70% of the average opening area. It can be seen that the unevenness of the opening area is extremely large in a screen printing plate using a screen member applied with a skew.

<Screen printing plate with openings in rolled metal foil>

FIG. 7A is a view showing a plurality of finger electrode patterns arranged in one direction with respect to a pattern for finger electrodes of a screen printing mesh member 40a formed of a rolled metal foil; An enlarged plan view of the elliptical openings 32. FIG. 7B is an enlarged plan view showing a plurality of rectangular openings 34 arranged in one direction with respect to the finger electrode pattern of the screen printing mesh member 40b formed of rolled metal foil. FIG. 8A shows a pattern for finger electrodes of a screen printing plate using the screen printing mesh member 40 a of FIG. 7A, as seen from the printing surface of the line pattern 38 provided with the photosensitive emulsion 36. An enlarged plan view of a plurality of oval-shaped openings 32 arranged in a direction. FIG. 8B shows the pattern for the finger electrode of the screen printing plate using the screen printing screen member 40b of FIG. 7B, as seen from the printing surface of the line pattern 38 caused by the photosensitive emulsion 36 provided. An enlarged plan view of a plurality of rectangular openings 34 arranged in a direction.

As shown in FIGS. 7A and 7B, the screen-like mesh members 40 a and 40 b formed by the rolled metal foil are provided with openings 32 and 34 of the same size. As shown in FIGS. 8A and 8B, the screen printing plate using the screen printing mesh members 40 a and 40 b formed of the rolled metal foil is the opening portion 32 exposed by the line pattern 38 opened in the resin 36. , 34 are the same in design. Actually, the irregularities of the dimensions during etching are within ± 5 μm with respect to the widths of the respective openings, so that they all have substantially the same size. In addition, the area distribution of the openings is also very narrow, and the standard deviation is also reduced. For example, when the interval between the openings 32 and 34 is a 70 μm pitch (PW), Table 2 shows the average area of the openings 32 and 34 with respect to the width W of the line pattern 38 and the standard deviation of the opening area. At this time, the opening width (AW) of the blade coating surface was 44 μm. In addition, in Table 3, when the interval between the openings 32 and 34 is a 80 μm pitch (PW), the distance from the width W of the line pattern 38 The average area of the mouth portions 32 and 34 and the standard deviation of the opening area. At this time, the opening width (AW) of the blade coating surface was 50 μm.

The standard deviation of the area of the opening at any time can be controlled within 10% of the average area of the opening. That is, in a screen printing plate using a screen member, the standard deviation from the area of the openings exposed by the in-line pattern reaches 70% of the average area, which is significantly worse.

FIG. 11 shows a line pattern of the printing plate 50 using the screen member of FIGS. 6 (a) to (e) and the printing plate of the screen printing mesh members 40a and 40b formed of the metal foil of FIG. 8B. A graph of the relationship between the width and the average area of the openings in the line pattern. FIG. 11 shows a printing plate 50 using a screen member (# 360-Φ16CL) with a symbol ◆. Again, yes In the screen printing mesh member 40b formed of a metal foil, when the interval between the opening portions 34 is a pitch of 70 μm, and the opening width of the scraped surface is 44 μm, it is indicated by the symbol ▲. It should be noted that when the interval between the openings 34 is 80 μm and the opening width of the doctor blade surface is 50 μm, the screen member 40b for screen printing formed of metal foil is represented by symbol ■.

As shown in FIG. 11 and the results of the printing test, if the average area of the openings is 2000 μm ² or more (2000 μm ² ), the paste will be excessively discharged, and the finger electrodes will bleed out after printing. That is, as for the width of the line pattern (emulsion opening width), it can be seen that the line width of the finger electrodes to be printed is as thick as about 15 to 20 μm. This is remarkable when using a screen printing plate in which a screen member having a perforated metal foil is rolled. This is conceivable as a result of the area of the opening that is most suitable for the printing conditions.

On the other hand, in a screen printing plate using a screen member (# 360-Φ16CL) having an average opening area of 1000 to 1200 μm ² , bleeding of finger electrodes after printing was suppressed. However, the width of the line pattern (the opening width of the emulsion) is smaller than the area (◆ 670μm ²⁾ opening 700μm ^2, an opening portion of the paste by creating barriers between the wires 51, the finger electrodes may be printed after the confirmation to the blade damage. Disconnected.

From the above results, by the average area of the opening portion ² is set, for example at least 700 m, preferably 800 m ² or more is provided, 2000 m ² or less, more preferably ² or less is provided in a range of 1800 m, to obtain necessary and sufficient paste The ejection performance, that is, the paste ejection performance without disconnection and scratches, and without exudation, can be obtained.

Fig. 12 is for a screen member (# 360- Φ16CL) The printing plate 50 and the printing plate of the screen printing mesh member 40b formed of the metal foil of FIG. 8B are graphs showing the relationship between the width of the line pattern and the standard deviation of the opening area in the line pattern. FIG. 12 shows a printing plate 50 using a screen member (# 360-Φ16CL) with a symbol ◆. The screen member 40b for screen printing made of metal foil is represented by the symbol ▲ when the interval between the openings 34 is a pitch of 70 μm and the opening width of the scratch-coating surface is 44 μm. It should be noted that when the interval between the openings 34 is 80 μm and the opening width of the doctor blade surface is 50 μm, the screen member 40b for screen printing formed of metal foil is represented by symbol ■.

Referring to FIG. 12, a screen printing plate using a screen printing mesh member 40b having an opening in a rolled metal foil, regardless of the line pattern width (emulsion opening width), Area unevenness (standard deviation) is as small as 150 μm ² or less. On the other hand, it turns out that the standard deviation of the area of the opening part of the screen printing plate using a screen member is 450 micrometer <^2> or more very large.

A screen printing plate using a screen printing mesh member provided with an opening in a rolled metal foil by etching is easily affected by external disturbance of printing conditions, and it is conceivable that the standard deviation is due to the opening area Extremely small. Since there is only a very narrow opening area distribution centered on the average opening area, if the viscosity at the time of printing changes due to changes in the viscosity of the paste, etc., it is easy to deviate from the optimum conditions.

In contrast, it is conceivable that because the standard deviation of the area of the openings of the screen member is very large, there are openings of various areas, and they are also susceptible to changes in printing conditions, and it is easy to reproduce the same Printing characteristics.

However, the screen member has a relatively small area distribution with an area of 600 μm ² or less across the opening. In this way, it is conceivable that the area of the opening is less than 600 μm ² , because the paste cannot pass well, so the blockage of the opening between the wires 51 is not only not helpful for printing, but also induces the net at the mass production site. The increase in the number of plate cleaning times increases the number of stoppages of the printing device, which causes problems such as a reduction in throughput.

Therefore, the present inventors completed the present invention by the following screen printing plate, which is hard to be affected by external interference to printing conditions, that is, finding a screen printing plate that can achieve high robustness. First, the mesh member for screen printing for which an opening is provided by metal foil by etching or the like is scratched. The disconnection does not occur, and an average value of an appropriate opening area where bleeding does not occur can be obtained. Next, a plurality of openings having a certain degree of area distribution are intentionally provided with the standard deviation of the area of openings to a certain degree centering on the appropriate average area.

Specifically, the screen member for screen printing of the present invention has a certain area distribution with respect to the plurality of openings exposed by the line pattern. Specifically, the standard deviation of the areas of the plurality of openings in the line pattern is in a range of 3.8 W (μm ² ) or more (20W + 10) (μm ² ) or less.

Thereby, external disturbances in printing conditions such as changes in printing characteristics with respect to changes in viscosity time of the paste are less likely to be affected, that is, a screen printing plate having high robustness can be realized.

In addition, since the wire mesh member (# 360-Φ16CL), which has become the mainstream in the thin line region, has already determined the interval between the wires 51, it is impossible to set the standard deviation of the opening area to 400 μm ² or less.

(Reference example)

The metal foil was rolled, and a screen printing plate made of a 25 μm-thick stainless steel SUS301 by using a etched screen member was produced here, and a screen printing plate (# 360-Φ16CL) was used to make the screen printing plate. The printing test was performed twice.

The pitch of the openings of the finger electrode pattern of the screen printing mesh member made of stainless steel SUS301 foil was 70 μm, and the interval of the openings was 44 μm. Set this to 70/44. That is, the openings are arranged at a certain pitch and have a certain size. The screen member for screen printing is provided with two types of line patterns having a width W (emulsion opening width) of 40 μm and 35 μm by plate-making. The resin (emulsion) used for plate-making was manufactured by Kyowa Chemical Co., Ltd. (ERS-2P), and the thickness of the resin (emulsion) was 10 μm.

On the other hand, the same resin (emulsion: manufactured by Kyowa Chemical Industry Co., Ltd. (ERS-2P)) was used for the plate making of the wire mesh member (# 360-Φ16CL), and the thickness of the resin (emulsion) was also 10 μm. In addition, two types of line patterns with a width W of 35 μm and 40 μm are provided.

The screen printing plate using the screen member for screen printing made of SUS301 foil and the screen printing plate using the screen member were printed on polycrystalline Si substrates twice every other day under the same printer and printing conditions. Pattern to measure the width of the finger.

The printing press is made by Microelectronics Technology Co., Ltd., with a blade of 200mm / s, printing pressure: 80N, blade angle: 70 °, pitch: 1.5mm The conditions are the same for the second printing. The same silver paste is used.

However, even when printing is performed on the same screen, the same paste, and the same printing conditions, a significant difference can be seen between the two printed screen finger widths. For example, when the width of the line pattern (emulsion opening width) is 35 μm, the difference in the line width of the finger electrodes due to a screen printing plate using a screen member is 4 μm or less. On the other hand, the line width of the finger electrode caused by the screen printing plate of the above-mentioned 70/44 screen printing mesh member after the perforation of SUS301 was also reduced by 8 μm.

In other words, it is known that the screen-shaped screen member made of stainless steel SUS301 foil which is arranged at a certain pitch and has a certain size of openings is significantly affected by changes in printing conditions during the second printing.

[Example]

The mesh member for screen printing used in the screen printing plate of Example 1 is a line pattern 18 divided by two straight lines separated by a width of 35 μm and a width of 35 μm in a range of 10 μ to 60 μm. , the standard deviation of the area of the plurality of openings 12, 14 of the inner portion 18 of the line pattern is 460μm ^2, and in the range (μm ²⁾ or less than ^{(20W + 10) 3.8W (2} μm).

Therefore, even when printing, external disturbances in printing conditions such as changes in the viscosity of the paste over time occur, and the most suitable area range of the plurality of openings 12 and 14 is changed. The area has a distribution, and can correspond to the most suitable area range after the change. Therefore, according to the screen member 10 for screen printing, the printing characteristics are less likely to be subjected to printing. The influence of external disturbances of the conditions, that is, high robustness can be obtained.

In addition, the present disclosure includes any combination of at least one of the aforementioned various embodiments and at least one of the embodiments, and at least one of the various embodiments and examples can be achieved. Party effect.

[Industrial availability]

According to the screen member for screen printing of the present invention, the standard deviation of the area of the plurality of openings in the line pattern divided by the two straight lines separated by the width W is 3.8 W (μm ² ) or more (20W + 10) ) (μm ² ) or less. Here, it is possible to provide a screen printing plate that is not easily affected even when external disturbances in printing conditions occur.

Claims (5)

A mesh member for screen printing is formed by a metal foil. The mesh member for screen printing is characterized in that a plurality of openings are arranged along one direction, and the long side direction is the aforementioned one direction and spans the aforementioned plurality. The standard deviation of the area of the plurality of openings in the opening pattern with respect to a line pattern defined by two straight lines separated by a width W of a range of 10 μm to 60 μm in a direction that intersects the aforementioned one direction. It is in a range of 3.8W (μm ² ) or more (20W + 10) (μm ² ) or less. The screen-shaped member for screen printing according to item 1 of the patent application range, wherein the average value of the area of the openings in the line pattern is in a range of 700 to 2000 μm ² . According to the mesh member for screen printing according to item 1 or 2 of the scope of patent application, the thickness of the metal foil is 5 μm or more and 30 μm or less. The mesh member for screen printing according to item 1 or item 2 of the patent application scope, wherein the metal foil includes a group consisting of stainless steel, titanium, titanium alloy, nickel, nickel alloy, copper, copper alloy, and aluminum alloy. Selected at least one. A screen printing plate comprising: the aforementioned mesh member for screen printing described in item 1 or 2 of the scope of patent application; a resin covering the plurality of openings arranged along the one direction; and a long The side direction is the aforementioned one direction and is provided across the plurality of openings. For the direction intersecting the aforementioned one direction, the resin opening area is divided into a line pattern by two straight lines separated by a width W ranging from 10 μm to 60 μm. .