JP4055881B2 - Nozzle for sandblasting - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention belongs to the technical field of a sandblasting apparatus, and particularly relates to a sandblasting nozzle used when a rib is formed by a sandblasting method in a manufacturing process of a plasma display panel (hereinafter referred to as PDP).
[0002]
[Prior art]
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.
[0003]
FIG. 1 shows an example of the configuration of an AC type PDP. This figure shows a state in which the front plate and the back plate are separated from each other. As shown in the figure, two glass substrates 1 and 2 are arranged in parallel and facing each other, and both serve as a back plate. The glass substrate 2 is held at regular intervals by ribs 3 provided in parallel to each other. On the back side of the glass substrate 1 serving as the front plate, a composite electrode composed of the sustain electrode 4 that is a transparent electrode and the bus electrode 5 that is a metal electrode is formed in parallel with each other, and a dielectric layer 6 is formed covering the composite electrode. The protective layer 7 (MgO layer) is further formed thereon. In addition, address electrodes 8 are formed between the ribs 3 so as to be orthogonal to the composite electrode on the front side of the glass substrate 2 serving as a back plate, and are parallel to each other. The phosphor 10 is provided so as to cover the wall surface of the rib 3 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. And the fluorescent substance 10 is light-emitted by the ultraviolet-ray which arises by this discharge, and an observer visually recognizes the light which permeate | transmits a front plate.
[0004]
As a method for forming the ribs on the back plate of the PDP as described above, it is common to perform baking after performing overprinting and patterning of a glass paste by screen printing, but this method is complicated in process. However, since good line width accuracy cannot be obtained, recently, a glass paste is applied on the substrate with a predetermined thickness and dried, and a mask having sandblast resistance is formed in a pattern on it. Thereafter, sand blasting is performed through the mask to grind the glass paste and pattern the ribs having a desired shape, followed by firing.
[0005]
[Problems to be solved by the invention]
The apparatus for patterning the ribs of the PDP by the above-described sandblasting method originally used a so-called “round nozzle” having a circular injection portion as a nozzle for injecting abrasive. However, due to the improvement in production tact, machining unevenness has become a problem, so in recent years each company has been developing a so-called “slit nozzle” with a wider ejection width. And although this slit nozzle has been put into practical use in part, the current one is still incomplete, and when compared with the conventional round nozzle, the processing unevenness is reduced when the production tact is improved. However, it is still in a situation where it can be recognized as unevenness, and it is not satisfactory in terms of processing accuracy.
[0006]
When ribs are patterned by sandblasting, the abrasive spray nozzle is an important part of determining processing quality. That is, there are various factors that affect the cutting shape, but the processing quality is particularly affected by the internal structure of the injection nozzle. Therefore, in order to solve the above-described problems, the present invention is to optimize the internal structure of the slit type nozzle used in the sandblasting apparatus.
[0007]
[ Means for Solving the Problems ]
The present invention is a slit-type nozzle that injects abrasives with a sandblasting device, and has a cylindrical introduction part that introduces a mixed gas of abrasives and air, and a box shape that controls the flow of the introduced mixed gas The flow control unit and a slit for injecting the mixed gas are provided at a position shifted from the center on the front end side of the flow control unit, and the direction inside the flow control unit is perpendicular to the slit toward the slit. The inclined surface corresponding to the direction where the slit is displaced is a, and the inclined surface corresponding to the direction where the slit is displaced is a. of the inclination angle with respect to the flow direction when the b, a <30 °, b > a, is characterized by satisfying the b-a <20 °.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
In making the present invention, the present inventors first performed a simulation by arbitrarily setting the cutting shape in order to know what cutting shape the slit type nozzle would exhibit. Specifically, multiple cutting shapes are set when a solid plate is fixed, and cutting is performed with different feed amounts (pitch) for each cutting shape, resulting in uneven machining at the center and edge of the substrate. I looked at the situation. As a result, as shown in FIG. 2 (A), it has been found that the cutting amount in the central portion is the largest in the longitudinal direction of the slit, and the distribution having a distribution that decreases substantially symmetrically toward both ends is good. did. Specifically, the cutting shape is preferably a parabola or a V shape. However, this is an ideal shape, and in fact, as shown in FIG. 2B, in addition to the central part, a portion that can be sharply cut at both ends is likely to appear. Processing unevenness is improved. However, if the dimensions are as shown, it is desirable that d ₁ /D≦0.4 and d ₂ / d ₁ ≧ 0.5.
[0010]
Next, a slit nozzle of the type shown in FIGS. 3 and 4 was used, and grinding was actually performed by changing the internal structure of the nozzle.
[0011]
The illustrated slit nozzle N includes a cylindrical introduction part 15 for introducing a mixed gas of abrasive and air, a box-shaped flow control part 20 for controlling the flow of the introduced mixed gas, and a slit for injecting the mixed gas. The slit S is provided at a position shifted from the center on the distal end side of the flow control unit 20. If the slit S is at the center, the flow of the mixed gas from the introduction portion 15 goes straight to the slit S, and the mixed gas injected from both ends of the slit S is reduced. Therefore, the flow is agitated by shifting the position of the slit S from the center so that a large amount of mixed gas is ejected from both ends of the slit S.
[0012]
The flow control unit 20 forms a box shape with the front plate 21 and the rear plate 22 having a large area, the two side plates 23 and 24 having a small width, and the shoulder plate 25, and the front block 26 and the rear side are formed therein. The block 27 is accommodated. A slit S is formed by both the blocks 26 and 27, and the two inside the flow control unit 20 narrow toward the slit S in a direction perpendicular to the slit S. Inclined surfaces α and β are provided. In terms of dimensions, the thicknesses of the front block 26 and the rear block 27 are 6 mm and 13 mm, respectively, and the width of the slit S is 1 mm. The length of the slit S is 100 mm, and the depth is 50 mm. The overall length of the flow control unit 20 is 170 mm.
[0013]
The inclination angles of the inclined surfaces α and β of the front block 26 and the rear block 27 in the flow control unit 20 with respect to the flow direction are a and b, respectively. And the front side block 26 and the rear side block 27 which changed these inclination angles a and b variously were prepared, and these were rearranged and grinding was performed. Specifically, first, a plurality of substrates were prepared by applying glass paste with a predetermined thickness and drying. Then, as shown in FIG. 5, one substrate G was fixed, and the slit nozzle N spraying the abrasive was scanned 8 times (four reciprocations) above the substrate G. Then, the cross-sectional shape at the A line in FIG. 5 was measured, and the cutting shape of the nozzle when the inclination angles a and b were changed was obtained. A part thereof is shown in FIG.
[0014]
Next, based on the cutting shape of the nozzle in each combination, a cutting simulation is performed when the substrate G is transported in the direction perpendicular to the scanning direction of the slit nozzle N (same as the actual processing) as shown in FIG. The variation in the cutting depth at the center (X line) and the end (Y line) in the figure was calculated. The evaluation results are shown in Table 1.
[0015]
[Table 1]
[0016]
From Table 1, it can be seen that the cutting shape is good when the conditions of a <30 °, b> a, and ba−20 <20 ° are satisfied.
[0017]
【The invention's effect】
As described above, according to the present invention, the internal structure of the slit type nozzle used in the sand blasting apparatus is optimized, so that the machining unevenness is reduced by injecting the abrasive from such an injection nozzle. Thus, a rib having a good shape can be patterned.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an example of a plasma display panel with a front plate and a back plate separated from each other.
FIG. 2 is an explanatory diagram showing a good cutting shape.
FIG. 3 is a front view and a bottom view of a slit nozzle.
4 is a side view of the slit nozzle shown in FIG. 3. FIG.
FIG. 5 is an explanatory diagram showing how a slit nozzle is scanned.
FIG. 6 is an explanatory diagram showing some of the graphs used for evaluation.
FIG. 7 is an explanatory diagram showing a state in which a slit nozzle is scanned in the same manner as in actual processing.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1, 2 Glass substrate 3 Rib 4 Sustain electrode 5 Bus electrode 6 Dielectric layer 7 Protective layer 8 Address electrode 9 Dielectric layer 10 Phosphor 15 Introduction part 20 Flow control part 21 Front board 22 Rear board 23, 24 Side board 25 Shoulder board 26 Front block 27 Rear block α, β Inclined surface G Substrate N Slit nozzle a, b Inclination angle

Claims (1)

A slit-type nozzle that injects abrasives with a sandblasting device, a cylindrical introduction part that introduces a mixed gas of abrasives and air, and a box-like flow control part that controls the flow of the introduced mixed gas And a slit for injecting the mixed gas, the slit is provided at a position shifted from the center on the tip side of the flow control unit, and narrows in the direction perpendicular to the slit toward the slit inside the flow control unit 2 An inclined angle with respect to the flow direction of the inclined surface corresponding to the side opposite to the side where the slit is displaced is a, and the inclined angle corresponding to the direction of the inclined surface corresponding to the direction where the slit is displaced is provided. A sandblasting nozzle characterized by satisfying the conditions of a <30 °, b> a, and ba−20 <20 ° when the inclination angle is b .