JP2002289090A - Forming method for electrode pattern by offset printing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a forming method for an electrode pattern by an offset printing method that solves a whisker-like defect generated when the electrode pattern is printed by the offset printing method. SOLUTION: An electrode pattern is build-up printed on a substrate by an offset printing method using a conductive ink containing, at least a conductive powder and a firing-removable organic component. The conductive ink contains a compound of at least more than two kinds of different particle-shaped conductive powders as the conductive powder and a flake-like conductive powder that the shape of particle of 5 to 40 mass percentage in the compound is flake- like. Then, the pattern for the electrode is fired and formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for forming an electrode pattern by offset printing.

[0002]

2. Description of the Related Art Conventionally, as a method of forming a fine electrode pattern, a pattern is formed on a glass substrate by a screen printing method or a photolithography method using a pattern forming paste containing a conductive powder, and then fired. To form an electrode pattern. However, the formation of the electrode pattern by the screen printing method has a limit of printing accuracy due to the elongation of the mesh material constituting the screen printing plate, and the formed pattern has meshes or bleeding of the pattern. There is a problem that the edge accuracy of the pattern is low. In addition, although the photolithography method can form a highly accurate electrode pattern, the manufacturing process is complicated, the material loss is large, and the reduction of the manufacturing cost is limited.

For this reason, attempts have been made to reduce the cost of forming a fine electrode pattern by using an offset printing method which has a simple process and has high productivity. In this offset printing method, a conductive ink containing a conductive powder is supplied to an intaglio or planographic printing plate, and the ink pattern on the printing plate is transferred to an electrode formation via a blanket, and then fired. Electrode patterns are formed by decomposing and volatilizing organic components.

The offset printing method has an advantage that an electrode pattern can be formed with higher precision than the screen printing method, and the amount of ink used is smaller than that of the photolithography method. Furthermore, in the photolithography method,
The cross-sectional shape in the width direction of the electrode pattern formed by sintering is rectangular. For example, when a dielectric layer is formed thereon, like an electrode pattern of a plasma display panel, the edge of the electrode breaks through the dielectric layer. However, since the cross-sectional shape in the width direction of the electrode pattern obtained by the offset printing method is a semi-cylindrical shape, the above-mentioned trouble caused by the edge of the electrode occurs. Absent.

[0005]

However, usually,
When thick printing of about 5 to 30 μm is performed on a glass substrate by offset printing, as shown in FIG.
A whisker defect 3 in which the ink jumps out from the contour of the print pattern 2 formed on the whiskers occurs. This is because the static electricity generated by the friction between the glass substrate and the blanket attracts the ink part with the cohesive failure surface or projection when the ink is filled into the plate, when the blanket receives the ink from the plate, or when the ink is transferred. What happens.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method of forming an electrode pattern by offset printing which eliminates a whisker defect generated when the electrode pattern is printed by offset printing.

[0007]

The present inventors have conducted research to eliminate whiskers and found that at least two conductive powders were used.
By using a conductive ink containing a mixture of conductive powders having different particle shapes of more than one kind, and having a flake-like conductive powder having a particle shape of 5 to 40% by mass in the mixture, The present invention has been found that defects are reduced, and that the occurrence of whisker defects is drastically reduced by using the above conductive ink in combination with a substrate having a surface resistance of 1 × 10 ¹¹ Ω or less. Was completed.

The first aspect of the present invention solves the problem of the present invention, in which an electrode pattern is formed on a substrate by offset printing using a conductive ink containing a conductive powder and at least an organic component that can be removed by firing. Is a method of forming an electrode pattern which is fired after printing, comprising a mixture of at least two kinds of conductive powders having different particle shapes as the conductive powder, and 5 to 40 mass% of particles in the mixture. It is characterized by using a conductive ink containing flake-like conductive powder having a flake shape.

In the present invention, the flake-like conductive powder has a D50 particle size of 1 to 3 as measured by the microtrack method.
Those having a thickness of 0 μm, preferably 2 to 15 μm can be used.

In the present invention, the conductive powder other than the flake-shaped conductive powder contained in the conductive ink has a D50 value of 002 to 6 μm, preferably 0.1 to 3.5 μm, as determined by the Microc method. More preferably, 0.2 to 2.
Those having a range of 0 μm can be used.

The invention described in claim 4 is another means for solving the problems of the present invention, wherein the substrate is made of a material that can be removed by firing, and has a surface resistance of 1 × 10 ¹¹ Ω / □ or less. Using a substrate subjected to antistatic treatment as described above, containing a mixture of at least two or more conductive powders having different particle shapes as conductive powder, and having a particle shape of greater than 0% by mass and 40% by mass or less in the mixture. It is characterized by using a conductive ink containing flake-like conductive powder in the form of flakes.

In the present invention, a substrate formed by applying a resin solution containing a conductive polymer on a substrate and then drying it is most preferable as the substrate subjected to antistatic treatment.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for forming an electrode pattern by offset printing according to the present invention will be specifically described.
First, a conductor containing a mixture of at least two or more conductive powders having different particle shapes as the conductive powder, and a flake-like conductive powder in which the mixture has a flake shape in a 5 to 40 mass% particle shape. Make ink. Using this conductive ink, a fine pattern such as an electrode pattern of a plasma display panel is thickly printed on a glass substrate by offset printing, and then fired.

By using the above conductive ink, the generation of whiskers can be suppressed. Table 1 shows the effect of preventing the generation of whiskers by the mass percentage of the flake-like conductive powder. Table 2 shows the effect of preventing the occurrence of whisker defects by the particle size of D50 value of the flake silver powder contained in the conductive ink by the microtrack method. Table 3 shows the effect of preventing the generation of whisker defects depending on the particle diameter of the D50 value of the spherical or microcrystalline silver fluid contained in the conductive ink. In Tables 1, 2, and 3, ◎ ++ has the greatest effect of preventing whisker defects, ＋+ indicates that the effect of preventing whisker defects is particularly large, ◎ indicates a large effect of preventing whisker defects, and ○ indicates the whisker defects. △ indicates that the effect of preventing the generation of whiskers is slightly inferior but is generally acceptable, and X indicates that the effect of preventing the generation of whiskers is not observed. Regarding the printing shape, ○ indicates good, Δ indicates slightly inferior but generally acceptable, and × indicates poor.

[0015]

[Table 1]

[0016]

[Table 2]

[0017]

[Table 3]

As shown in Table 1, the mass percentage of the flake-shaped conductive powder is preferably 5 to 40 mass%, more preferably 20 to 40 mass%, and most preferably 20 to 40 mass%.
３０30% by mass. Further, as shown in Table 2, the range of the particle size of the flake-like conductive powder applicable in the present invention is 1 to 30 μm, more preferably 2 to 15 μm.
μm. As shown in Table 3, the particle size of the spherical or microcrystalline silver powder applicable in the present invention is 0.02 to 6 μm.
m, preferably 0.1 to 3.5 μm, most preferably 0.2 to 2.0 μm.

On a glass substrate, ions (potassium, sodium,
, Chlorine, etc.) after firing
With no residual carbon or vitrified, surface potential is 1 ×
10 ¹¹After applying the liquid to form a layer below Ω, dry
An antistatic layer is formed. Specifically, for example, Marubishi Yuka Kogyo
Conductive polymer PPY-14 (made of polypyrrole with water
Dispersion / Epoxy crosslinker / A
Resin liquid containing conductive polymer composed of krill resin
Coated on a substrate with a spinner and dried at 160 ° C for 2 minutes
Those obtained by forming an antistatic agent layer in this way are suitable. So
In addition to the above, for example, N103X manufactured by Colcoat Co., Ltd.
Roxane antistatic layer, plasma display panel after drying
Underlayer for flannel (PDP) (main component is lead-based glass frit)
Color paste, resin, cellulosic material, etc.)
Antistatic agent layer containing the above conductive polymer is also possible
Is the most effective. In addition, the charging containing the conductive polymer
The conductive polymer contained in the prevention material layer is conductive after sintering.
Function of the glass substrate is reduced, and the insulation of the glass substrate is impaired.
It is not something.

By using the above-described conductive ink in combination with the substrate on which the antistatic layer is formed as described above, the occurrence of whiskers is drastically reduced. Table 4 shows the above conductive polymer P
The effect of preventing generation of whiskers when a substrate coated with a liquid containing PY-14 is used is shown. In Table 4, ◎ + indicates that the effect of preventing whisker defects was particularly excellent, ◎ indicates that the effect of preventing whisker defects was large, は indicates that the effect of preventing whisker defects was generated, and △ indicates that the effect of preventing the generation of whisker defects was slightly inferior. , × indicate that the effect of preventing generation of whiskers was not observed. Regarding the print shape, ○ indicates good, Δ indicates slightly inferior but generally acceptable, and × indicates poor.

[0021]

[Table 4]

As shown in Table 4, when the mass percentage of the flake silver fluid is more than 0 and 40 or less, preferable results are obtained, and when it is 5 to 40, more preferable results are obtained.
At a value of 30, very favorable results were obtained.

Table 5 shows the relationship between the reduction in surface potential due to the surface treatment of the glass substrate and the occurrence of whiskers. Table 3
◎ indicates that the effect of preventing the generation of whiskers was large, ○ indicates that the effect of preventing the generation of whiskers was low, △ indicates that the effect of preventing the generation of whisker defects was slightly inferior, but was generally acceptable, and × indicates that the effect of preventing the generation of whiskers was not observed. Show.

[0024]

[Table 5]

As shown in Table 5, when the substrate was subjected to a surface treatment and a conductive ink containing flake-like conductive powder was used, a particularly good effect of preventing the generation of whiskers was observed.

Next, examples of the present invention will be described. (Example) A conductive ink having the following composition was prepared. Conductive ink spherical silver powder: 61 parts by weight (tap density: 3.5 g / cm ³ , particle size D50: 0.7 μm) Flaky silver powder (D50: 5 μm): 16 parts by weight Glass frit: 3 parts by weight ( Bi ₂ O ₃ glass, average particle size: 0.9 μm) Resin: 16 parts by weight (Mariarim: copolymer of allyl ether, maleic anhydride and styrene) Solvent: 2 parts by weight (Aroma Free No. 6)

As a substrate, soda glass (thickness: 2.1 m)
m, size: 350 mm × 450 mm), and a liquid composed of polymer PPY-14 / epoxy-based cross-linking agent / acrylic resin manufactured by Marubishi Yuka Kogyo Co., Ltd. was applied on the surface by a spinner and then heated at 160 ° C. It was dried for 2 minutes and subjected to an antistatic treatment.

A printing plate (waterless plate (DG2), 100 μm in image width, manufactured by Toray Industries, Inc., width of 100 μm) was assembled on an Ector LCD printing machine manufactured by Kouyousha Seisakusho, and an NBR blanket was assembled on a blanket cylinder as printing conditions. The substrate subjected to the antistatic treatment was set, and an electrode pattern was printed under the following conditions. Further, as a printing condition 2, a silicon blanket was assembled, and the substrate subjected to the antistatic treatment was set, and the electrode pattern was printed under the following conditions.

Printing conditions 1 Printing speed 600 mm / sec Printing pressure 0.2 mm Number of times of printing 4 times

Printing condition 2 Printing acceptance speed 50 mm / sec Printing transition speed 600 mm / sec Printing pressure 0.2 mm Number of times of printing 3 times Blanket Silicon

Under any of the printing conditions 1 and 2, no whisker defects were observed during printing, and the printing shape was good.
After printing, firing was performed to form an electrode pattern of the plasma display panel.

[0032]

As described in detail above, according to the method for forming an electrode pattern by offset printing according to the present invention, a mixture of at least two types of conductive powders having different particle shapes is contained as the conductive powder. In addition, it is possible to suppress the generation of whisker defects generated during printing of an electrode pattern by using a conductive ink containing a flake-shaped conductive powder having a flat 5 to 40 mass% particle shape in the mixture.

Further, this effect can dramatically eliminate whiskers by printing on a substrate which has been subjected to an antistatic treatment using the above conductive ink.

[Brief description of the drawings]

1A and 1B show a state of occurrence of a whisker defect, wherein FIG.
(B) is a plan view.

[Explanation of symbols]

 1 substrate 2 print pattern 3 beard defect

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[Procedure amendment]

[Submission date] March 23, 2001 (2001.3.2)
3)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction contents]

[0016]

[Table 2]

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Michio Ikuhara 1-1-1, Ichigaya-Kaga-cho, Shinjuku-ku, Tokyo F-term in Dai Nippon Printing Co., Ltd. (reference) 5C027 AA01 AA02 5C040 GC19

Claims (5)

[Claims] 1. A method for forming an electrode pattern, comprising: printing an electrode pattern on a substrate by offset printing using a conductive ink containing at least a conductive powder and an organic component that can be removed by firing; A conductive ink containing a mixture of at least two kinds of conductive powders having different particle shapes as powders, and a flake-like conductive powder having a particle shape of 5 to 40% by mass in the mixture. A method for forming an electrode pattern by offset printing. 2. The flake-like conductive powder according to claim 1, wherein the particle diameter of the D50 value measured by a microtrack method is in a range of 1 to 30 μm, preferably 2 to 15 μm. A method for forming an electrode pattern. 3. The conductive powder other than the flake-shaped conductive powder contained in the conductive ink is D-tracked by a microtrack method.
The particle size of 50 values is 0.02 to 6 μm, preferably 0.1 to
3. The method for forming an electrode pattern by offset printing according to claim 1, wherein the thickness is in a range of 3.5 [mu] m, more preferably 0.2 to 2.0 [mu] m. 4. A substrate made of a material that can be removed by baking and subjected to an antistatic treatment so as to have a surface resistance of 1 × 10 ¹¹ Ω / □ or less, and at least two or more types of particles as conductive powder. Using a conductive ink containing a mixture of conductive powders having different shapes, and a flake-shaped conductive powder in which the particle shape is larger than 0% by mass and equal to or less than 40% by mass in the mixture. Of forming an electrode pattern by offset printing. 5. The offset printing according to claim 4, wherein the substrate subjected to the antistatic treatment is formed by applying a resin solution containing a conductive polymer on the substrate and then drying it. Of forming an electrode pattern according to the above.