JPH10144211A - Thick film pattern forming method - Google Patents

Abstract

(57) [Problem] To form a thick film pattern at small intervals so that a pattern forming paste does not undergo dimensional change even after a firing step. A method for forming a thick film pattern includes a step of patterning a pattern forming paste on a substrate and forming a pattern layer in close contact with the substrate through a firing step.
An anti-shrinkage layer 12 is formed on a substrate 11 using a material having an action of preventing shrinkage during heating, an underlayer 13 is further formed on the anti-shrinkage layer 12, and a pattern forming paste 14 is formed on the underlayer 13. The shrinkage prevention layer 12, the underlayer 13 and the pattern layer are fired simultaneously so as to be patterned. The shrinkage preventing layer 12 does not undergo dimensional change during firing, and therefore the pattern forming paste 1
4 does not shrink in the width direction even after the firing step.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a process for manufacturing a plasma display panel (PDP), a field emission display (FED), a liquid crystal display (LCD), a fluorescent display, a hybrid integrated circuit, or the like. The present invention relates to a method for forming a thick film pattern.

[0002]

2. Description of the Related Art Conventionally, as a method of forming a thick film pattern of this kind, a paste for a conductor or an insulator is applied in a pattern on a glass or ceramic substrate by a screen printing method and then adhered to the substrate through a firing step. A method for forming a patterned pattern is known. Alternatively,
There is also known a method in which a photosensitive paste is applied to the entire surface of a substrate, patterned by a photolithography method, and then the pattern forming paste is baked.

[0003]

By the way, in the above-mentioned paste for pattern formation, the whole line shrinks during firing. Specifically, the line width shrinkage is about 10 to 30%. For example, using a paste with a line width shrinkage of 20%,
Assuming that a pattern having a line width of 100 μm is applied at 100 μm intervals and fired, the line width after firing is 80 μm and the distance between lines is 1 μm.
It becomes 20 μm. On the other hand, when a line pattern is formed by a screen printing method or a photolithography method using a photosensitive paste, the distance between the lines is 20 μm in view of the resolution.
m is the limit. Therefore, as shown in FIG. 1, assuming that the line width before firing is A μm, the line spacing B after firing is [2 × (0.
1 × A) +20] μm. For example, the line width A before firing
Is 100 μm, the line spacing B after firing is 40 μm
Will be. Further, assuming that the line width of the address electrode in the current AC type PDP is about 70 μm,
It is impossible to form a gap of less than m, which makes it difficult to manufacture a high-definition PDP.

[0004] When the AC-type PDP is driven in two parts, it is necessary to divide the address electrode into two parts as shown in FIG. 2.
It is about. Therefore, similarly to the line width, the interval D after firing is [2 × (0.1 × A) +20] μm. For example, considering the current AC type PDP, since the line width is 70 μm, 3
It is impossible to provide an interval of 4 μm or less. However, when the interval D is increased, the central portion of the panel does not turn on, or even if turned on, it is possible to visually confirm that the discharge is different from the others or that the wire is broken.

The present invention has been made in view of the above circumstances, and an object of the present invention is to form a thick film pattern in which a pattern forming paste does not undergo dimensional change even after a firing step. It is to provide a method.

[0006]

In order to achieve the above-mentioned object, the present invention provides a method for forming a pattern layer on a substrate, comprising the steps of: patterning a paste for forming a pattern on a substrate; In the film pattern forming method, an anti-shrinkage layer is formed on a substrate using a material having an action of preventing shrinkage upon heating, an underlayer is further formed on the anti-shrinkage layer, and a paste for pattern formation is formed on the underlayer. It is characterized in that patterning is performed, and the shrinkage prevention layer, the underlayer and the pattern layer are fired simultaneously.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Substrates which can be used in the present invention include glass, metal, ceramic and the like. Here, a case where a glass substrate is used and an electrode is formed as a thick film pattern on the glass substrate will be described as an example.

First, as shown in FIG. 3A, a shrinkage preventing layer 12 is formed on a glass substrate 11. In particular,
One or more inorganic powders such as alumina, silica, boron oxide, titanium oxide, magnesium oxide, calcium oxide, strontium oxide, barium oxide, calcium carbonate, etc., which soften at the firing temperature of the underlayer or pattern layer In other words, it is formed by using an inorganic material that does not soften at 650 ° C. or lower mixed with a binder resin and a solvent to form a paste, or a film formed into a sheet to form a sheet. The average particle size of the inorganic powder is 0.1 to 2.0 μm.
m are preferably used.

The shrinkage preventing layer hardly shrinks in the horizontal direction of the pattern and shrinks only in the vertical direction (thickness direction) during firing. That is, these pastes and sheets forming the anti-shrinkage layer do not cause dimensional change because the expansion due to heat and the shrinkage when the resin flies are substantially balanced.

Further, as shown in FIG. 3B, an underlayer 13 is formed on the shrinkage preventing layer 12. This underlayer 13
Is for improving adhesion to electrodes and preventing migration, and is formed by applying a paste containing a glass softening at a low temperature, such as a PbO-based material, a Bi ₂ O ₃ -based material, or a ZnO-based material. Shrinkage prevention layer 1 formed on glass substrate 11
2 is insulative, but does not melt by heat, and thus is inferior in film-forming properties. Therefore, when an electrode is directly formed thereon, peeling of the electrode occurs. Therefore, by providing the base layer 13 that is melted by heat and penetrates into the shrinkage prevention layer 12, the film forming property and the mechanical strength are improved.

Next, as shown in FIG. 3C, an electrode paste 14 is patterned on the glass substrate 11 on which the anti-shrinkage layer 12 and the underlayer 13 are formed by means such as a screen printing method. Alternatively, a photosensitive electrode paste may be applied to the entire surface and dried, or an electrode paste layer may be once formed on a film and transferred to a substrate, and then patterned by photolithography.

Next, baking is performed to remove the resin from the electrode paste 14, thereby forming an electrode 15 in a close contact state as shown in FIG. 3 (d). In this firing step, 300 to 40
At 0 ° C., the resin component in the electrode paste flies and the film is reduced, causing it to shrink in the horizontal direction. However, since the powder mainly composed of alumina thermally expands, it apparently does not shrink in the horizontal direction. The electrode 15 does not change in line width and does not peel off. Further, when the temperature reaches 450 to 600 ° C., the glass frit shrinks due to softening, and further melts and adheres to the underlayer 13. Further, the underlayer 13 is melted and melted into the shrinkage prevention layer 12 to become the integrated mixed layer 16.
After the firing, the cooling is performed. However, since the coefficient of thermal expansion of the mixed layer 16 is the same as the coefficient of thermal expansion of the metal sheet 11 and the electrode 15, the electrode 15 does not cause a phenomenon such as dimensional change or peeling. Thus, 650 ° C.
Inorganic powder that does not soften below 65% gradually from the rich layer
A mixed layer 16 having a gradient structure that changes to a glass-rich layer having a softening point of 0 ° C. or lower is formed, and an electrode 15
Is formed.

[0013]

EXAMPLE A paste material was prepared by adding a binder resin to a mixed powder of 80% by weight of alumina and 20% by weight of silica having an average particle size of about 1.0 μm, and this paste material was coated on a glass substrate. Thus, an anti-shrink layer was formed. After drying, a paste containing PbO-based glass was coated on the anti-shrinkage layer to form an underlayer.

Subsequently, a photosensitive electrode paste of the following composition B containing a photosensitive resin of the following composition A is prepared, and this is coated on a glass substrate on which a shrinkage preventing layer and an underlayer are formed by screen printing. An electrode paste layer having a dry film thickness of 15 μm was formed. Then, the electrode paste layer was exposed through a mask, and a developing process was performed to form an electrode pattern layer having a line width of 50 μm and a line interval of 20 μm.

<Composition A> Alkali-developing binder polymer 100 parts by weight (methyl methacrylate / methacrylic acid copolymer) Polyoxyethylated trimethylolpropane triacrylate 60 parts by weight Photoinitiator (“Irgacure 907” manufactured by Ciba Geigy) 10 Parts by weight

<Composition B> 20 parts by weight of photosensitive resin of composition A 70 parts by weight of silver powder (average particle size) 5 parts by weight of glass frit ｛Main components: Bi ₂ O ₃ , SiO ₂ , B ₂ O ₃ (alkali-free) Average particle size: 1 μm, softening point: 600 ° C. 20 parts by weight of dipropylene glycol monomethyl ether 1 part by weight of thickener

Next, the shrinkage preventing layer, the underlayer, and the electrode pattern layer are baked at a time to form a film having a thickness of 6 μm and a line width of 48 μm.
An address electrode for PDP having a line interval of 22 μm was formed. As a result, a fine electrode pattern having a film thickness of 5 μm or more and a line width of 30 μm or less could be formed.

[0018]

As described above, according to the present invention, an anti-shrinkage layer is formed on a substrate using a material having an action of preventing shrinkage during heating, and an underlayer is further formed on the anti-shrinkage layer. Since the patterning paste was patterned on the ground layer and baked simultaneously, the shrinkage preventing layer did not undergo dimensional change during firing, so that the patterning paste on top of the firing step Since it does not shrink in the width direction even after passing,
Thick film patterns can be formed at intervals before firing, that is, at small intervals.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a relationship between a line width and a line before and after firing of a linear pattern.

FIG. 2 is an explanatory diagram showing a relationship between intervals before and after firing when a linear pattern is divided into two.

FIG. 3 is a process chart for explaining a method of forming a thick film pattern according to the present invention.

[Explanation of symbols]

 A Line width (before firing) B Between lines (after firing) D Interval (after firing) 11 Substrate 12 Shrinkage prevention layer 13 Underlayer 14 Electrode paste 15 Electrode 16 Mixed layer

Claims (4)

[Claims] 1. A method for forming a thick film pattern, comprising the steps of: patterning a pattern forming paste on a substrate; and forming a pattern layer in close contact with the substrate through a firing step.
An anti-shrinkage layer is formed on the substrate using a material that has an anti-shrinkage effect when heated, a base layer is further formed on the anti-shrinkage layer, and a patterning paste is patterned on the base layer. A method of forming a thick film pattern, wherein the prevention layer, the underlayer, and the pattern layer are baked simultaneously. 2. The method for forming a thick film pattern according to claim 1, wherein the anti-shrinkage layer is formed of a material comprising an inorganic powder that does not soften at 650 ° C. or lower and a binder resin. 3. A thick film pattern formed by the method according to claim 1, wherein the film thickness is 5 μm or more and the distance between lines is 30.
Thick film pattern of not more than μm. 4. A substrate having a thick film pattern formed by the method according to claim 1, wherein the inorganic powder which does not soften at 650 ° C. or less is gradually formed on the substrate from a rich layer at 650 ° C.
A substrate with a thick film pattern, wherein a glass-rich layer having the following softening point is formed, and a thick film pattern is formed thereon.