JP2000311616A - Air discharge hole for plasma display panel substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the breakdown of a substrate in a baking process and a heating process by performing the chamfering to the periphery of an air discharge hole of a plasma display panel. SOLUTION: An air discharge hole 1 of a plasma display substrate is provided in a glass substrate of the plasma display panel, and chamfering 1 m is performed to the periphery of an opening of the hole passing through the glass substrate. This chamfering can be performed to both surfaces of the glass substrate, or can be provided in the only periphery of the air discharge hole of an outer air surface side of a panel body at the time of assembling the substrate. The shape of chamfering can be thread chamfering or round chamfering.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a substrate for a plasma display panel (PDP). Specifically, PDP
The present invention relates to a technique for improving the strength of a glass substrate in a baking or heat process by forming a specific shape of an exhaust hole used for exhausting gas or filling a gas in a panel in a paneling process with respect to a rear plate or a front plate.

[0002]

2. Description of the Related Art In general, a PDP is provided with a pair of electrodes regularly arranged on two opposing glass substrates (a front plate and a back plate), between which a gas mainly composed of Ne, Xe, He or the like is supplied. It has a sealed structure. Then, a voltage is applied between the electrodes to generate a discharge in the minute cells around the electrodes, so that each cell emits light and display is performed. There are two types of PDPs, a direct current type (DC type) in which the electrodes are exposed to the discharge space, and an alternating current type (AC type) in which the electrodes are covered with an insulating layer. And a refresh driving method and a memory driving method.

FIG. 6 is an exploded perspective view showing an example of the configuration of an AC type PDP. This figure shows a state in which a front plate made of a glass substrate 12 and a back plate made of a glass substrate 11 are separated from each other. As shown, two glass substrates 11 and 12 are arranged in parallel and opposed to each other. The two are held at a fixed interval by a barrier rib 8 provided on a glass substrate serving as a back plate. On the rear side of the glass substrate 12 serving as a front plate, composite electrodes X and Y each composed of a sustain electrode 14 which is a transparent electrode and a bus electrode 13 which is a metal electrode are formed in parallel with each other, and a dielectric A layer 16 is formed, and a protective film 19 is further formed thereon.
(MgO layer) is formed.

A barrier rib 8 is provided on the front side of the back plate.
The address electrodes 15 are formed in parallel with each other. Further, a phosphor layer 18 is provided so as to cover the wall surface of the barrier rib 8 and the cell bottom surface. This address electrode, after forming an electrode paste material consisting of silver and low melting point glass frit by pattern printing using a screen printing method, or after forming a predetermined pattern by a photolithography method using a photosensitive electrode material, It is formed by firing. Further, after applying and firing the dielectric layer 17, the barrier ribs 8 are formed.

As a method of forming the barrier rib 8, there are a screen printing method, a sand blast method, a so-called embedding method using a dry film resist, and a method of pressing a molding die having a specific shape to form the shape. Among these, the method of forming by the sand blast method is becoming mainstream. In this method, address electrodes 15 or dielectric layers 1 are formed in a predetermined pattern on a glass substrate serving as a back plate.
On a substrate provided with 7, a glass paste to be a barrier rib is applied to a specific pattern with a predetermined thickness by a coating method such as screen printing or die coating, and dried,
Further, a photosensitive dry film resist is laminated, exposed and developed through a photomask on which a specific pattern is formed, thereby forming the dry film resist into a specific pattern shape.

Generally, in an AC-driven PDP, the pattern shape is constituted by lines and spaces having a fixed line width and a constant pitch. After the dry film resist pattern is formed, sand blasting is performed, and the portion where the dry film resist is formed becomes a barrier rib because the paste remains, and the portion where the dry film resist is removed by development does not leave the paste and a phosphor screen is formed. It becomes a cell. Then, peel off the dry film resist,
By firing, a barrier rib structure is formed. Thereafter, a phosphor screen is formed by a screen printing method or a photolithography method using a phosphor paste having photosensitivity. On the other hand, the front plate is completed by forming a transparent electrode and a bus electrode in a predetermined pattern on a glass substrate, and then forming a dielectric layer and further a protective layer (MgO layer).

[0007] A front panel and a rear panel having these structures are bonded to form a bonded panel, and the panel is completed by exhausting the inside of the panel and enclosing a specific gas (mainly composed of Ne, Xe, He, etc.). I do. In order to exhaust and fill the gas, it is necessary to provide a hole having a sufficient exhaust capacity or a sufficient diameter for filling the gas in the back plate or the front plate. Therefore, this exhaust hole is located on any part of the substrate (a corner or frame that is not normally visible to the observer).
It is provided in. In addition, after exhausting, a glass short tube is attached around this hole using a sealing agent, and then gas is sealed by evacuating. Then, the opening of the glass tube is melted by applying heat with a burner and sealed off.

FIG. 5 is a view showing a conventional exhaust hole. FIG. 5A is a plan view of a conventional substrate having an exhaust hole 10, FIG. 5B is a cross-sectional view taken along line AA of FIG.
(C) is an enlarged plan view showing around the exhaust hole. FIG.
As shown in FIG. 1A, the conventional exhaust hole 10 is usually provided with a diameter of about 0.1 mm.
It is often 5 mm to 5 mm, and is provided at a position 2 mm to 50 mm from the side of the glass substrate 11 in many cases. In the drawing, a dotted portion is a region where any one of the constituent films 2 constituting the PDP panel, such as an address electrode and a dielectric layer, is formed. As shown in FIG. 5 (B), the conventional exhaust hole 10 is formed as a straight hole (diameter r) without chamfering. However, as shown in FIG. 5 (C), a small chipping 10c or a crack is formed around the hole. 10k was generated, and the substrate was often damaged from the portion in the firing or heating process.

[0009]

However, the back plate and the front plate need to be subjected to a heating step such as a firing step and a drying step in order to form the respective constituent layers. At that time, a large stress is applied to the glass substrate. As a result, the glass substrate frequently breaks or cracks starting from the exhaust hole portion as described above. This is considered to be one of the causes of such breakage due to a minute chip (also referred to as chipping or chipping) formed particularly at the inner end face of the exhaust hole during the processing of the exhaust hole. Although the rate of occurrence of substrate damage due to one baking step or heating step is within several percent in actuality, P
In the DP panel manufacturing process, in each of the steps of electrode formation, dielectric layer application, barrier rib formation, and phosphor layer application, baking is performed each time, and there is a heat process such as heat drying. The quantity is a quantity that cannot be ignored. Therefore, the present invention is intended to break the glass substrate even in a baking step or a heat step which is indispensable in processing the PDP substrate,
It was completed by studying the shape of the exhaust hole without cracking.

[0010]

According to a first aspect of the present invention, there is provided a plasma display panel having a chamfer around an opening of an exhaust hole provided in a glass substrate of the plasma display panel. An exhaust hole of the plasma display panel substrate, which has been processed. Due to such exhaust holes, the substrate is less likely to be damaged in the thermal process.

According to a second aspect of the present invention, there is provided a plasma display panel substrate according to the first aspect, wherein chamfering is provided around the exhaust holes on both sides of the glass substrate. According to a third aspect of the present invention, in the exhaust hole of the plasma display panel substrate according to the first aspect, chamfering is provided only on the outside air side surface of the panel body when the glass substrate is assembled. By doing so, in any case, it is possible to reduce occurrence of damage to the substrate in the thermal process. According to a fourth aspect of the present invention, in the exhaust hole of the plasma display panel substrate according to the first and second aspects, the chamfering shape is a thread chamfer or an R chamfer. With such a chamfered shape, in any case, the substrate is less likely to be damaged.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. In addition, each drawing schematically shows the size, shape, and positional relationship of each part so that the present invention can be understood. In the following description, specific materials and conditions may be used, but these materials, conditions, and the like are merely examples, and the present invention is not limited thereto.

FIG. 1 shows a state in which an exhaust hole according to the present invention is provided in a glass substrate. FIG. 1A is a plan view thereof, and FIG.
(B) shows the cross section of the exhaust hole when the double-sided yarn is chamfered in the cross section along the line AA in FIG. 1 (A), and FIG. 1 (C) shows the cross section of the exhaust hole when the single-sided yarn is chamfered. In FIG. 1, 11 is a glass substrate, 1 is an exhaust hole of the present invention, and 2 is any constituent film formed on a PDP glass substrate.
As shown in FIG. 1 (B), in the case of double-sided yarn chamfering, a chamfered portion 1m on one side x is formed on the inner surface side of the panel with respect to the exhaust hole 1 having a diameter r, so that the inner surface of the panel has a diameter r + 2x.
Is formed. The yarn chamfering is a case where an inclined surface having a linear cross section is provided with respect to the straight portion of the exhaust hole, and the chamfering angle (α in FIG. 1B) is usually 10 °.
It is formed to about 60 °.

The periphery of the opening is increased in diameter by 2 ×, so that, for example, when the dielectric layer and the barrier rib layer are formed, the constituent film 2 is easily affected by abnormal film thickness. In particular, when a coating film is formed by a coating method, there is a great effect of restricting the formed surface. FIG. 1C shows a case where the chamfering process is performed only around the opening of the exhaust hole on the outer surface of the panel. In this case, since the opening does not expand on the inner surface side of the panel, the constituent film 2 is not affected.

FIG. 2 is a diagram showing the types of chamfers. FIG. 2A shows thread chamfering, and FIG. 2B shows R chamfering. The thread chamfering is a case in which an edge surface (yarn chamfered portion 1i) which is substantially linearly inclined with respect to the perforation is provided around the opening at a predetermined angle as described above, and the R chamfering is a circular arc-shaped edge surface (R This refers to the case where the chamfered portion 1r) is provided. In the present invention, it has been confirmed that the same effect can be obtained in any case.

Next, a situation in which a glass substrate is perforated or chamfered will be described. FIG. 3 is a diagram illustrating an example of a tool for drilling a straight hole. In the case of a straight circular hole, the rear end portion 48 is attached to the spindle of the machine by using a core drill 4 having a hollow cylindrical shank 41 to which a drill blade portion 45 containing diamond abrasive grains is attached at the tip end, and is rotated and drilled. Is usually performed. If you only want to drill from one side,
When the drill last penetrates the glass substrate, it often breaks around the opening, so that the alignment is performed and the drilling is performed alternately or simultaneously from both sides.
In general, the cutting is performed while flowing water from inside the shank for the purpose of discharging cutting chips, lubricating, and preventing heat generation. The drill blade may be provided in an annular shape, but as shown in FIG.
Having the above makes it easier to discharge cutting chips.

In the case of chamfering, there are a case where chamfering is performed after forming a straight hole and a case where boring and chamfering are performed simultaneously. FIG. 4 is a diagram illustrating an example of a tool that performs drilling and chamfering simultaneously. In this case, the diamond core drill 4 is used, but a seamer portion 44 for chamfering is provided at the root of the drill blade portion 45. This portion is also constituted by a chip containing diamond abrasive grains. The shape of the seamer and the length of the drill bit are changed depending on the application and purpose.
After the drill blade 45 forms a hole, the seamer grinds the periphery of the opening to form a chamfered shape. It is clear that the machining efficiency is improved by performing the drilling and chamfering at the same time.

In the case of a straight hole, chipping 10c and crack 10k are likely to occur around the opening as shown in FIG. When stress is applied to the glass substrate in the thermal process, the crack expands from the portion, resulting in breakage of the substrate.

Such chipping and the like can be removed by chamfering to form a beautiful surface. According to the test results, it has been confirmed that as a result of performing various kinds of firing treatment on the glass substrate subjected to such chamfering, the substrate is hardly damaged. Moreover,
It has been confirmed that a sufficient effect can be obtained by providing the chamfering process only on the outside air side when a glass substrate panel is assembled. Further, it has been confirmed that the chamfer provided in the exhaust hole is more effective when the exhaust hole is provided close to the center line of the glass substrate. If the exhaust hole is provided close to the center line of the glass substrate, compared to the case where it is at the corner portion, it is easier to receive stress during the heating process and the ratio of breakage is higher than before,
In that case, breakage can be reduced.

[0020]

Embodiments of the present invention will be described below with reference to FIG. The reference numerals in the embodiments correspond to the reference numerals given to the respective drawings. (Example 1) In a firing step after forming an address electrode,
For the purpose of examining the number of occurrences of substrate breakage, a test was performed on a substrate with exhaust holes that had been subjected to yarn chamfering on both sides. The glass substrate 11 has a thickness of 2.8 mm and a size of 96 mm.
4 mm × 570 mm high strain point glass (“PD-200” manufactured by Asahi Glass Co., Ltd., hereinafter referred to as “GA”) and “PP-8” manufactured by Nippon Electric Glass Co., Ltd., hereinafter “GN”
Is displayed. ) Was used for each 500 sheets. The exhaust hole has a diameter r = 2 ± 0.2 mm and a chamfered portion x =
0.4 to 0.6 mm, and the chamfer angle α was set to 45 °.

The formation and firing of the address electrodes are performed under the following conditions. <Formation of Electrode> After the address electrode 15 was formed on the glass substrate 11 using an electrode paste material composed of silver and a low-melting glass frit, it was dried at 170 ° C. and fired. The address electrode is a line & space pattern.
Pitch 0.36mm on the back substrate with one width 0.15mm
Thus, a pattern was formed by the photolithography method for 2556 pieces. A continuous firing furnace was used for firing. The firing temperature of the firing furnace was a peak temperature of 600 ° C. and the total time was 300 minutes.

Example 2 The same conditions as in Example 1 were used, except that the yarn chamfering was performed under the same conditions as in Example 1 for a substrate with an exhaust hole which was chamfered only on the outside air side of the substrate. went. GA and GN were each tested for 500 sheets.

Example 3 A test was performed on a substrate with an exhaust hole, which was performed under the same conditions as in Example 1 except that the R-chamfering process was performed only on the surface of the substrate on the outside air side. GA and GN
Were tested for 500 sheets each. The curvature x of the R chamfer was set to 0.2 to 0.7 mm.

(Comparative Example 1) A test was performed under the same conditions as in Example 1 except that the substrate had a straight hole without chamfering. GA and GN were each tested for 500 sheets. Note that the diameter r of the straight hole is 2 ± 0.2 mm, which is the same as in the first to third embodiments.

(Test Results) The test results of Examples 1 to 3 and Comparative Example 1 are summarized in Table 1 below.

[Table 1] (Table 1)

From the above results, it was confirmed that the number of breaks was significantly reduced when chamfering was performed around the exhaust hole. Also, it was confirmed that it was not necessary to provide chamfering around the openings on both sides, and that the effect could be sufficiently obtained only by providing it on the outside air side of the panel, which would not hinder the formation of various PDP constituent films.

[0027]

In the case of the exhaust hole of the plasma display panel of the present invention, since the periphery of the opening is chamfered, even if it receives a heat history in a firing step or the like, the exhaust hole is generated from a minute defective portion of the exhaust hole. The number of cracks, breaks, and cracks in the substrate can be significantly reduced.

[Brief description of the drawings]

FIG. 1 shows a state in which an exhaust hole of the present invention is provided in a glass substrate.

FIG. 2 is a diagram showing types of chamfers.

FIG. 3 is a diagram showing an example of a tool for drilling a straight hole.

FIG. 4 is a diagram illustrating an example of a tool that performs drilling and chamfering simultaneously.

FIG. 5 shows a state in which a conventional exhaust hole is provided in a glass substrate.

FIG. 6 is an exploded perspective view showing one configuration example of an AC type PDP.

[Explanation of symbols]

 Reference Signs List 1 exhaust hole 1m chamfered portion 1i yarn chamfer 1r R chamfer 2 component film 4 core drill 8 barrier rib 10 conventional exhaust hole 10c chipping 10k crack 11 glass substrate (back plate) 12 glass substrate (front plate) 13 bus electrode 14 sustain electrode 15 address Electrodes 16, 17 Dielectric layer 18 Phosphor layer 19 Protective film (MgO layer)

Claims (4)

[Claims] 1. An exhaust hole of a plasma display panel substrate, wherein an exhaust hole provided in the glass substrate of the plasma display panel is chamfered around an opening of the hole penetrating the glass substrate. 2. The exhaust hole of a plasma display panel substrate according to claim 1, wherein the chamfering process is provided around the exhaust hole on both surfaces of the glass substrate. 3. The exhaust hole of a plasma display panel substrate according to claim 1, wherein the chamfering process is provided only around the exhaust hole on the outside air side surface of the panel body when the glass substrate is assembled. 4. The exhaust hole of a plasma display panel substrate according to claim 1, wherein the chamfering shape is thread chamfering or round chamfering.