JP2005138229A - Abrasive for sand blast - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an abrasive capable of pattern-cutting low melting glass in a time shorter than that of the conventional art without damaging the processing surface, in sand blast processing of a flat-panel display. <P>SOLUTION: As the abrasive for sand blast used in the flat-panel display, a glass bead that has an average grain size of 5 μm to 50 μm, 25% or more of barium oxide and/or titanium oxide as components, 50% or more of total content of barium oxide and/or titanium oxide, and high specific gravity of 4 or more. Thus, a partition can be formed in a short time by increasing the pattern cutting speed of the low melting glass for forming the partition without damaging the glass substrate. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to an abrasive used for sandblasting in the formation of partition walls in the production of flat panel displays such as plasma displays, field emission displays, and plasma address display panels.

Conventionally, as a patterning method used for forming a partition wall of a flat panel display such as a plasma display panel, cellulose or an acrylic resin and an organic material are mixed with a low melting point glass powder such as lead oxide mixed with a powder such as alumina or titanium oxide. A solvent is mixed to prepare a partition wall forming material paste, and the paste is applied to a glass substrate by screen printing or a coater and dried to form a coating film. A resist film with a predetermined pattern is formed using a photosensitive resist ink or a dry film for sandblasting, and calcium carbonate, soda lime glass beads, alumina, or stainless steel powder is used as an abrasive. After the film portion is ground and removed, the space containing the low melting point glass is included. It was to form a partition wall forming material and a coating film made of the electrode forming material and fired.

Soda-lime-based glass beads that have been used for sandblasting of flat panel displays in the past to increase the yield of the bulkhead forming process during processing, as large-scale flat panel displays can be mass produced at low cost. Compared with calcium carbonate powder, alumina powder and stainless steel powder, it was necessary to use an abrasive that can be processed at a high speed and at a high speed, with little damage to the partition walls and less damage to the dielectric and electrodes in the substrate. .

The energy for cutting low-melting glass with sandblasting increases as the speed of the abrasive increases and the specific gravity of the abrasive increases.

Calcium carbonate, alumina powder, and soda lime glass beads that were conventionally used for cutting low-melting glass all have a low specific gravity of 4 or less, so the cutting speed of low-melting glass is slow when abrasives are sprayed onto the substrate. There was a problem that was not suitable for high-speed processing.

Further, although the specific gravity of the stainless steel powder is high and suitable for high-speed processing, there is a problem that iron adheres to the processed glass substrate surface and the substrate surface becomes red due to iron oxide after the substrate is baked.

The present invention uses glass beads mainly composed of barium oxide and titanium oxide having a lower hardness and a higher specific gravity than glass mainly composed of silicon oxide used as a glass substrate as a means for solving the above problems. Damage to glass substrates used in flat panel displays is reduced, and abrasive particles hit the substrate because of its higher specific gravity compared to conventionally used alumina powder, silicon oxide-based glass beads, and calcium carbonate powder. It is an object of the present invention to provide an abrasive for sandblasting used for forming partition walls in a flat panel with good processing efficiency, which can increase the processing energy and increase the processing speed when processed under the same conditions.

The abrasive used in the present invention is an abrasive used when a partition wall is formed by drying a low melting point glass paste applied on a substrate in flat panel display production, followed by pattern cutting by sandblasting, and the abrasive is Glass having an average particle diameter of 5 μm or more and 50 μm or less, containing 25% or more of barium oxide and / or titanium oxide as components, the total content of barium oxide and titanium oxide being 50% or more, and a true specific gravity of 4 or more It is an abrasive for sandblasting characterized by being a bead.

As shown in FIG. 1, the blasting device used in the present invention comprises a blasting device main body 23, a classifier 21 such as a cyclone, and a dust collector 20, and an abrasive spray nozzle 7 is provided in the blasting device main body.

The abrasive material injected from the abrasive material injection nozzle 7 in the blasting apparatus or the abrasive material supplied from the outside into the blast chamber passes through the conduit by a negative air pressure from the dust collector 20 and flows through the conduit to the cyclone, etc. The dust generated by cutting the crushed abrasive and work piece is collected by a dust collector, the usable abrasive enters the abrasive tank, and then passes from the abrasive supply device to the abrasive injection nozzle. The abrasive is supplied, and the abrasive is jetted from the abrasive jet nozzle.

After forming a mask pattern using a photosensitive dry film or the like on a glass substrate coated with a low melting point glass using a coater or the like, the average particle size is 5 μm or more and 50 μm or less as an abrasive, and barium oxide as a component And / or forming a partition wall for a flat panel display using glass beads having a titanium oxide content of 25% or more, a total content of barium oxide and titanium oxide of 50% or more, and a true specific gravity of 4 or more. The dry film is peeled off with a peeling solution and then fired to form the partition walls.

As the abrasive according to claim 1, glass beads having the following composition 1 and composition 2, and calcium carbonate powder and soda lime based glass beads, stainless steel powder and alumina powder having an average particle diameter of 20 μm, which have been conventionally used, are used. The low melting point glass paste having a height of 180 μm was cut under the same conditions by sandblasting, and the cutting speed of the low melting point glass according to the type of abrasive was examined.

Composition 1
TiO ₂ : 50%, Ba0: 30%, SiO ₂ : 2%, ZnO: 10%, CaO: 2%, ZrO: 4%

Composition 2
TiO ₂ : 85%, BaO: 40%, SiO ₂ : 13%, ZnO: 5%, CaO: 5%

Table 1 measures the number of nozzle passes when the substrate is cut by moving only the substrate nozzle under the processing conditions of a processing pressure of 0.1 MPa, a nozzle distance of 30 mm, a nozzle moving speed of 10 m / min, and an abrasive injection amount of about 500 g / min. This is a table comparing the cutting rates of the abrasives, and it was found that the glass beads of composition 1 and composition 2 could be processed efficiently in the shortest time.

The damage to the glass substrate, electrode and dielectric after sandblasting is greatest for alumina powder, followed by calcium carbonate powder, and soda lime-based glass beads and stainless steel powder show some damage on the glass surface, which is less than calcium carbonate. However, no glass beads mainly composed of barium oxide / titanium oxide were found.

In addition, when the abrasive remained in the low-melting glass, the state after firing was examined. As a result, it was found that calcium carbonate could cause foaming of the low-melting glass by carbon dioxide gas, and that the stainless powder was colored red. However, other glass beads and glass beads mainly composed of barium oxide / titanium oxide and alumina powder showed no particular problems.

〔Example〕
A 42-inch plasma display partition was formed by sandblasting using glass beads mainly composed of barium oxide / titanium oxide as an abrasive.

Asahi Glass Co., Ltd. is used as a low-melting glass paste mainly composed of lead glass, and the paste is applied to the entire surface of the glass substrate 16 on which the address electrodes 15 are previously attached by a roll coater 42 to form a coating film. Then, the coating film was dried with a dryer at 140 ° C. for 30 minutes (see step A in FIG. 2).

After drying, in step B, BF603 manufactured by Tokyo Ohka Kogyo Co., Ltd. was laminated as a dry film 14 for sandblasting on the coating film, and a glass mask 8 was placed thereon, followed by exposure with ultraviolet rays (exposure amount 200 mJ).

In step C, a dry film developer (sodium carbonate 0.3 wt aqueous solution) 32 was sprayed with a shower to wash out unexposed portions to form a resist film.

In step D, the substrate was set in a sandblasting apparatus, the average particle size was 18 μm as an abrasive, and the composition was TiO ₂ : 85%, BaO: 40%, SiO ₂ : 13%, ZnO: 5%, CaO: 5%. Sand blasting was performed using glass beads under an air pressure of a processing pressure of 0.07 MPa, and the coating film at portions not covered with the resist film was removed by grinding.

In Step E, the substrate after grinding and removal was placed in an alkaline solution (monoethanolamine 3% solution) to remove the resist film, washed with water and fired at 550 ° C. to form partition walls.

For example, the processing speed can be increased compared with soda glass glass beads and calcium carbonate powder that have been used in the past, and even if abrasives remain after firing, the glass substrate was not colored like stainless steel powder. .

The abrasive used in the present invention is used in the form described above, and has the effects described below.

The sandblasting abrasive used in the present invention is the same as the conventionally used abrasive when performing partition formation and electrode formation of a flat panel display compared to the conventionally used abrasive. When sandblasting was performed under the conditions, the processing speed could be increased, and there were no problems such as coloration after damage to the glass substrate or firing of the low melting point glass, and it was possible to form a good partition in a short time. .

It is explanatory drawing of the sandblasting apparatus used for a flat panel display. It is process drawing for demonstrating the process in which the back plate of a plasma display panel forms a partition by sandblasting.

Explanation of symbols

7 Nozzle for sandblasting 8 Glass mask 12 Partition wall forming material paste 13 Dry partition wall forming material paste 14 Dry film for sandblasting 15 Address electrode 16 Glass substrate 20 Dust collector 21 Classifier (Cyclone)
22 Processing Chamber Hopper 23 Sand Blast Processing Chamber 24 Air Blow Chamber 26 Nozzle Drive Unit 27 Conveyor Roller 28 Air Blow Nozzle 30 Abrasive Material 32 Dry Film Developer (Sodium Carbonate Aqueous Solution)
42 Roll coater

Claims (1)

An abrasive used for forming a partition of a flat panel display by sandblasting, wherein the abrasive has an average particle diameter of 5 μm or more and 50 μm or less and contains 25% or more of barium oxide and / or titanium oxide as a component, Or an abrasive for sandblasting, characterized in that the total content of titanium oxide is glass beads having a total specific gravity of 50% or more and a true specific gravity of 4 or more.

Images