JP2006318747A - Sandblast apparatus and method for sandblasting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sandblast apparatus which can effectively reuse sandblasted waste which is generated in large quantity when partitions of PDPs are sandblasted. <P>SOLUTION: The apparatus comprises a first storage tank for storing powder abrasives, a feeder which feeds the abrasives, a supply route for carrying the abrasives from the feeder, a processing device equipped with a sandblast gun which jets the abrasives carried by the supply route to a material to be processed, an exhaust passage for transporting abrasives jetted out of the processing device and a material to be ground by using negative pressure, a classifier which classifies the abrasives and the ground material supplied from the supply route, a second storage tank which stores the abrasives caught by the classifier, and a dust collector which collects dust discharged from the classifier. The classifier comprises a first classifier which removes fine power, a second classifier which removes coarse powder, and a third classifier which catches the abrasives and they are arranged in this order. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

Field of Invention

  The present invention relates to a sandblasting apparatus that performs grinding by causing a jet of powder dispersed in a gas phase to collide with a workpiece, and more specifically, a rib of a plasma display panel (hereinafter abbreviated as PDP). The present invention relates to a sandblasting apparatus and a sandblasting method that are suitably used for forming.

  In general, the sand blasting method is a technique that has been used as one of processing methods for forming a pattern on the surface of a substrate such as glass, marble, plastic, ceramics, leather, and wood. In this processing method, a resist for sandblasting is provided on the surface of a substrate, and a pattern is formed by selectively grinding by spraying an abrasive or the like on the exposed portion of the resist. And, after using a photosensitive resin having sandblast resistance as a resist for sandblasting, forming a mask pattern by photolithography, and then processing by spraying abrasive etc. on the exposed part, it is possible from fine processing Recently, it is used for forming a circuit board in which a metal pattern and an insulating pattern are mixed, particularly for forming a metal wiring pattern of PDP, an insulating pattern such as a rib and a phosphor.

  In general, a PDP has a structure in which a pair of electrodes regularly arranged on two opposing glass substrates are provided, and a gas mainly composed of Ne, Xe, or the like is enclosed therebetween. Then, a voltage is applied between these electrodes, and discharge is generated in minute cells around the electrodes, thereby causing each cell to emit light for display. In order to display information, cells arranged regularly are selectively discharged. There are two types of PDPs: a DC type (DC type) with electrodes exposed in the discharge space and an AC type (AC type) covered with an insulating layer, both of which vary depending on the display function and driving method. Further, it is classified into a refresh driving method and a memory driving method.

One substrate of the PDP has a partition wall and constitutes a back plate. As a method for forming a partition wall in such a back plate, it is common to perform baking after overprinting and patterning a glass paste by screen printing. However, since this method cannot provide good line width accuracy for the complicated process, recently, a glass paste is applied on a glass substrate in a predetermined thickness and dried, and then the sandblasting resistance is further improved. After forming a mask having a pattern into a pattern, sandblasting is performed through the mask to grind the glass paste (partition forming material layer) to pattern a partition having a desired shape, followed by baking. It has been. In the sand blasting process, inorganic particles such as glass beads having a particle size of about ₂ to 50 μm, SiC, SiO ₂ , Al ₂ O ₃ , ZrO ₂ are used as the abrasive.

  When the above-described inorganic fine particle abrasive is used, a large amount of mixed powder is produced in which the abrasive and the abrasive powder of the partition wall forming material layer are mixed during sandblasting. If this mixed powder is discarded as a waste material as it is, there is a problem in terms of environment and cost. Therefore, it is desired to reuse the mixed powder as a waste material.

In order to reuse the mixed powder discharged by the sandblasting process, it is necessary to separate the abrasive from the workpiece. In the separation step, the grinding material is collected by performing classification using a cyclone or the like, and the object to be ground having a fine particle size or the ground grinding material is collected by a dust collector. For example, in JP 2001-157966 A (Patent Document 1), a sandblasting device is provided with a cyclone classifier, and the abrasive and the partition material are separated by this classifier so that the waste can be reused. Devices that can be planned have been proposed.
JP 2001-157966 A

  However, even when the cyclone classifier is used as described above, it is difficult to completely separate the abrasive and the partition material by classification. In addition, aggregates of the object to be ground are generated in the classifier, or coarse foreign matter mixed in the exhaust path due to negative pressure is captured by the classifier, so the abrasives separated and collected by the classifier Grinding failure sometimes occurred when trying to use for sandblasting again.

  The inventors of the present invention have recently obtained the knowledge that, by using a multi-stage classification device, it is possible to separate and collect abrasives that do not contain coarse foreign matter and aggregates. The present invention is based on this finding.

  Accordingly, an object of the present invention is to provide a sandblasting apparatus that can effectively reuse a large amount of sandblasting waste generated when sandblasting a PDP partition wall. Another object of the present invention is to provide a method for sandblasting PDP partition walls using the sandblasting apparatus.

And the sandblasting device according to the present invention comprises a first storage tank for storing a fine powdery abrasive,
A supply device connected to the tank for supplying an abrasive;
A supply path for transporting the abrasive from the supply device;
A processing apparatus equipped with a sandblast gun for injecting abrasives transported from the supply path onto a workpiece;
An exhaust path for moving the abrasive and the material to be ground injected from the processing device by negative pressure;
A classification device for classifying the abrasive and the material to be ground supplied from the exhaust path;
A second storage tank for storing the abrasives collected by the classifier;
A dust collecting device for collecting dust discharged from the classification device,
The classification device is
A first classifier for removing fine powder,
A second classifier for removing coarse powder;
A third classifier for collecting abrasives,
The first classifier, the second classifier, and the third classifier are arranged in this order.

  According to the present invention, the fine powder is first removed by the first classifier to suppress the formation of aggregates, and then the coarse powder is removed by the second classifier, and the abrasive is removed by the third classifier. By collecting these first to third classifiers in this order in succession, it is possible to efficiently collect abrasives that do not contain coarse foreign matters and aggregates. Therefore, according to the sandblasting apparatus of the present invention, the used abrasive can be repeatedly used.

  The sandblasting apparatus of the present invention will be described with reference to the drawings.

  The schematic block diagram of the sandblasting apparatus which is one embodiment of this invention is shown in FIG.

  As shown in FIG. 1, a substrate 1 that is a workpiece is transported in a substrate processing chamber 2 at a predetermined speed by a substrate transfer means (not shown) such as a transport roller. A processing device 3 is disposed above the substrate 1 in the substrate processing chamber 2, and this processing device 3 is provided with a sandblast gun 4 that can inject an abrasive onto the surface of the substrate 1. The sand blast gun 4 is provided with a moving means (not shown), and can reciprocate in a direction perpendicular to the substrate transport direction. The surface of the substrate 1 is desired by spraying the abrasive from the sand blast gun 4. Processed into shape. The abrasive is supplied from the supply device 5 to the substrate processing chamber 2 through the supply path 6 in an air stream. As the nozzle shape of the sandblast gun 4, a slit type nozzle is preferable to a round type nozzle. By using a slit type nozzle, a wide range can be processed, and processing uniformity is improved.

  The grinding material sprayed onto the substrate 1 in the substrate processing chamber 2 is an object to be ground discharged by processing the substrate (for example, when the substrate is a PDP substrate, the object to be ground is a grinding powder such as a PDP partition wall forming material) And collected at the lower part of the hopper 7 provided in the substrate processing chamber, and discharged from the lower end of the hopper 7 to the exhaust path 8.

  The mixture of the grinding object and the object to be ground discharged to the exhaust path 8 is transported to the classifying device 9 in an air stream. In the present invention, as shown in FIG. 1, the classification device 9 includes a first classification device 10, a second classification device 11, and a third classification device 12. The mixed powder of the grinding object and the object to be ground transferred from the exhaust path 8 is first supplied to the first classifier 10. The fine powder contained in the mixed powder is separated by the first classifier 10. This fine powder is mainly composed of an object to be ground. The classifying means in the first classifying device is preferably wind power such as a cyclone.

  In this way, the fine powder classified by the first classifier 10 is discharged to the dust collector 13. On the other hand, the mixed powder from which the fine powder has been removed is once collected in the collection tank 14 and transferred from the collection tank 14 to the second classifier 11 through the transfer path. This transfer path is preferably provided with transfer means (not shown) for transferring the mixed powder in an air stream.

  Coarse foreign substances and aggregates of the object to be ground contained in the mixed powder transferred to the second classifier 11 are classified here. The classified coarse foreign matters and aggregates are transferred to the foreign matter recovery tank 15 and removed. In order to classify the relatively coarse powder in this way, the second classifier 11 preferably has a comb or a classifying means that combines a comb and wind power.

  Next, the mixed powder from which coarse foreign matters and aggregates have been removed is transferred to the third classifier 12 through a transfer path. Here, residual powder other than the abrasive that could not be removed by the first and second classifiers is removed. At this stage, since a relatively large powder does not remain in the mixed powder, it is preferable to use a classification means using wind power such as a cyclone.

  The classified residual powder is transferred to the dust collector 13 through the transfer path. As shown in FIG. 1, the dust collector may collect fine powder transferred from both the first classifier 10 and the third classifier 12 by one apparatus 13 as shown in FIG. Moreover, you may provide a dust collector separately for every classifier.

  On the other hand, the mixed powder from which the residual powder has been removed, that is, the abrasive, is transferred to the storage tank 16. The abrasive in the storage tank 16 is supplied again to the substrate processing chamber 2 by the supply device 5 through the supply path 6.

  In the present invention, as described above, the first to third classifiers are continuously provided in this order as the classifier, so that abrasives that do not contain coarse foreign matters and aggregates can be classified. Thus, the abrasive can be reused efficiently.

  In addition, each exhaust path and supply path may be provided with a foreign matter separating means (not shown) such as a metal mesh, if necessary, and a higher-purity ground material can be obtained by such a foreign matter separating means. Can do.

  Next, a method for forming a PDP partition using the sandblasting apparatus will be described.

  First, a partition wall forming paste is applied to a substrate such as glass and dried to form a partition wall forming material layer on the substrate. A photosensitive resin having sandblast resistance is provided on the partition wall forming material layer, and then exposed to an actinic ray through a photomask for exposure to develop into a desired pattern. The substrate on which the mask pattern is formed in this way is transferred to a sand blasting apparatus and subjected to sand blasting. A partition forming material layer other than the mask pattern is ground by the sand blasting abrasive sprayed from the sand blast gun, and a partition having a desired pattern is formed.

Sandblasting conditions is similar to the conventional sandblast method, preferably, the ejection pressure 0.001~3kg / cm ^2, an injection amount 100~5000g / min.

  The partition wall forming paste is a paste composition having a composition in which an inorganic powder such as a low melting glass powder and a refractory filler is a main component and an appropriate binder resin and solvent are added thereto. As the binder resin, a cellulose resin or an acrylic resin can be preferably used. By using such a resin, the grindability by sandblasting becomes extremely good.

  In this paste composition, first, an inorganic powder in which a low-melting glass powder, a refractory filler, a pigment and the like are mixed is pulverized by a ball mill or the like to adjust the particle size of each component. Next, the crushed inorganic powder is combed to remove coarse foreign matters and dried to prepare a frit. A binder resin and a solvent are added to the resulting frit to form an ink, thereby obtaining a paste composition.

  Next, an AC type PDP will be described as an example of a PDP manufactured using the above sand blasting apparatus.

  In FIG. 2, two glass substrates 21 and 22 constituting the PDP are arranged in parallel and facing each other, and both are provided by a partition wall 23 provided in parallel with each other on a glass substrate 22 serving as a back plate. It is held at regular intervals. On the back side of the glass substrate 21 serving as the front plate, a composite electrode composed of the sustain electrode 24 that is a transparent electrode and the bus electrode 25 that is a metal electrode is formed in parallel to each other, and a dielectric layer 26 covers the same. Is formed. A protective layer 27 (MgO layer) is formed on the dielectric layer 26. Further, address electrodes 28 located between the partition walls 23 are formed in parallel to each other on the front side of the glass substrate 22 serving as a back plate so as to be orthogonal to the composite electrode. A dielectric layer 29 is formed to cover the address electrodes 28, and a phosphor 20 is provided so as to cover the wall surface of the partition wall 23 and the cell bottom surface. The AC type PDP is a surface discharge type, and has a structure in which an AC voltage is applied between the composite electrodes on the front plate to discharge. The phosphor 20 emits light by the ultraviolet rays generated by this discharge, and the observer visually recognizes the light transmitted through the front plate.

  Hereinafter, although the sandblasting apparatus of the present invention will be described by way of examples, the scope of the present invention is not limited by these examples.

1. Preparation of substrate A glass substrate having a plane size of 1460 × 1050 mm and a thickness of 2.8 mm was prepared, and a large number of electrodes on stripes parallel to each other at 300 μm pitch were screen-printed on the surface of one side.

  Next, a low melting point glass paste was applied by screen printing so as to cover a predetermined position on the glass substrate including the formed electrode layer, and dried at 170 ° C. for 30 minutes to solidify the paste. Subsequently, the binder component was fired under a firing temperature of 90 minutes in total from peak temperature 585 ° C. to temperature rise to cooling, and the glass component was sintered to form a dielectric layer on the substrate.

  A low melting point glass paste using a cellulose-based resin as a binder is collectively coated with a die coater at a predetermined position on the substrate surface on the side where the dielectric layer is formed, and a peak temperature of 200 ° C. is applied for 70 minutes from temperature rise to cooling. Under the condition of holding for 15 minutes, the paste was dried and solidified to form a partition wall forming material layer.

  Next, a dry film (AX166FF, manufactured by Asahi Kasei Co., Ltd.) was laminated so as to cover the obtained partition wall forming material layer, and exposure development was performed through a photomask. In this manner, a resist mask for sandblasting having a parallel stripe pattern with a width of 90 μm and an interval of 210 μm was formed. The resist mask is formed such that the electrodes provided on the substrate are arranged at the exact center of the resist mask pattern interval of 210 μm. The developer used was an aqueous sodium carbonate solution having a concentration of 5 g / l.

2. Sandblasting Next, a sandblasting apparatus as shown in FIG. 1 was used to carry out sandblasting to form partition walls. First, a substrate provided with a sandblast mask was transferred to a substrate processing chamber by transfer means comprising a number of transfer rollers, and an abrasive was sprayed from the sandblast gun toward the surface of the substrate on the mask surface side. A stainless abrasive with an average particle size of 15 μm was used as the abrasive.

  The substrate processing chamber includes four sandblast guns that can reciprocate in a direction perpendicular to the substrate transport direction. Each sandblast gun is approximately perpendicular to the substrate from a 200 mm × 2.8 mm slit. It had a slit nozzle which injects an abrasive.

  After sandblasting, the resist mask provided on the partition wall was peeled off and removed with an aqueous sodium hydroxide solution having a concentration of 10 g / l. Furthermore, it was washed with pure water and dried at a peak temperature of 100 ° C. to remove moisture.

  The partition walls sandblasted as described above had a width of 80 μm, a height of 185 μm, and an interval between the partition walls of 220 μm. When the substrate after sandblasting was observed, all the partition wall forming material layers other than the portion where the resist mask was provided were ground and removed, and the dielectric layer and electrodes under the removed partition wall forming material layer No damage was caused to the layer and the glass substrate.

3. Preparation of PDP back plate By firing a glass substrate on which partition walls having a predetermined pattern are formed, lead glass, which is a low melting point glass component, is completely melted and the glass is fired, and the binder resin is incinerated. A face plate 1 was obtained.

4). Reuse of Abrasive Material A PDP back plate 2 was produced while classifying the mixed powder discharged by the sandblasting process using a sandblasting apparatus shown in FIG. Specifically, the mixed powder from which the fine powder has been removed by the first classifier 10 is collected in the collection tank 14, and then the coarse particles and the aggregate of the object to be ground are collected by the second classifier 11 and the third classifier 12. Then, the classified abrasives were supplied again to the supply device 15 to reuse the abrasives. The recycling process of the abrasive was sequentially and continuously performed during sandblasting.

  The partition wall of the PDP back plate 2 that was sandblasted while reusing the abrasive using the sandblasting apparatus of the present invention was compared with the partition wall of the PDP back plate 1 that was processed using a new abrasive material without being reused. And the quality was equivalent.

It is the structure schematic which showed an example of the sandblasting apparatus of this invention. It is the schematic of a plasma display panel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Substrate processing chamber 3 Processing apparatus 4 Sandblast gun 5 Supply apparatus 6 Supply path 7 Hopper 8 Exhaust path 9 Classifier 10 First classifier 11 Second classifier 12 Third classifier 13 Dust collector 14 Collection tank 15 Foreign material recovery tank 16 Storage tank 20 Phosphor 21, 22 Substrate 23 Bulkhead 24 Sustain electrode 25 Bus electrode 26 Dielectric layer 27 Protective layer 28 Address electrode 29 Dielectric layer

Claims (11)

A first storage tank for storing finely divided abrasives;
A supply device connected to the tank for supplying an abrasive;
A supply path for transporting the abrasive from the supply device;
A processing apparatus equipped with a sandblast gun for injecting abrasives transported from the supply path onto a workpiece;
An exhaust path for moving the abrasive and the material to be ground injected from the processing device by negative pressure;
A classification device for classifying the abrasive and the material to be ground supplied from the exhaust path;
A second storage tank for storing the abrasives collected by the classifier;
A dust collecting device for collecting dust discharged from the classification device,
The classification device is
A first classifier for removing fine powder,
A second classifier for removing coarse powder;
A third classifier for collecting abrasives,
The sand blasting device, wherein the first classifying device, the second classifying device, and the third classifying device are arranged in this order.   The sandblasting device according to claim 1, wherein a collection tank and a transfer device are arranged between the first classifying device and the second classifying device.   The sandblasting apparatus according to claim 1 or 2, wherein the workpiece is a plasma display member.   The sand blasting device according to any one of claims 1 to 3, wherein the second classifying device performs classification by a comb or wind power.   The sandblasting apparatus according to any one of claims 1 to 4, wherein the supply path and / or the exhaust path includes a foreign matter separating means.   The sandblasting apparatus according to claim 5, wherein the foreign matter separating means is a metal mesh.   The sandblasting device according to any one of claims 1 to 6, wherein the first classifying device and the third classifying device classify by wind power.   The sand blasting device according to any one of claims 1 to 7, wherein the dust collecting device is provided in the first classifying device and the third classifying device.   The sandblasting method using the sandblasting apparatus as described in any one of Claims 1-8.   A method for manufacturing a plasma display panel, comprising the method according to claim 9.   A plasma display panel obtained by the method according to claim 10.

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