JP4735313B2 - Plasma display panel and manufacturing method thereof - Google Patents

Description

  The present invention relates to a plasma display panel (hereinafter referred to as a PDP) that is a flat panel display device used for large televisions, public displays, and the like, and more particularly to a method for manufacturing the plasma display panel. The present invention relates to an exhaust pipe for enclosing gas and a method for manufacturing a PDP including the exhaust pipe.

  Since PDPs can achieve higher definition and larger screens, commercialization is progressing toward 65-inch class television receivers and large public display devices, and products exceeding 100 inches are also planned. Yes.

  Basically, a PDP is composed of a front plate and a back plate. The front plate covers a display electrode composed of a glass substrate of sodium borosilicate glass by a float method, a striped transparent electrode formed on one main surface of the glass substrate, and a metal bus electrode, and the display electrode. The dielectric layer functions as a capacitor, and a protective layer made of magnesium oxide (MgO) formed on the dielectric layer. On the other hand, the back plate is a glass substrate provided with pores for exhaust and discharge gas encapsulation (also referred to as introduction), and stripe-shaped address electrodes (also referred to as data electrodes) formed on one main surface thereof, It is composed of a base dielectric layer that covers the address electrodes, a partition formed on the base dielectric layer, and a phosphor layer that emits red, green, and blue light formed between the partitions.

  The front plate and the back plate are opposed to each other on the electrode forming surface side, and the exhaust pipe and discharge gas in the discharge space partitioned by the partition wall are sealed by the surroundings and exhaust and discharge gas introduction exhaust pipes with a sealing material. (Ne-Xe, 400 Torr to 600 Torr pressure) is sealed through the exhaust pipe, and the exhaust pipe (so-called tip pipe, hereinafter referred to as the tip pipe) is locally heated at an appropriate location. An operation of melting (chip-off) and hermetically sealing is performed. The completed PDP is discharged by selectively applying a video signal voltage to the display electrodes, and ultraviolet rays generated by the discharge excite each color phosphor layer to emit red, green, and blue light, thereby displaying a color image. Is realized.

  Further, in a flat panel display device such as a PDD, the discharge space formed by the opposed front plate, back plate and barrier ribs is exhausted and manufactured through a process of introducing gas, but the barrier rib height is extremely small. Therefore, conductance at the time of exhaust and gas introduction is extremely small. Therefore, it is desirable for the exhaust pipe to have as large an inner diameter as possible. For this reason, the exhaust pipe is required to be as thin as possible.

  In addition, low melting point glass mainly composed of lead oxide is generally used for the PDP dielectric layer and sealing material described above, but "lead-free" does not contain lead components in consideration of environmental issues in recent years. An example of using a lead-free material called “lead-less” is disclosed (for example, see Patent Documents 1, 2, 3, 4 and the like). Furthermore, conventional exhaust pipes are made of borosilicate glass containing lead, which has a relatively low softening point and excellent sealing process workability. The direction of using non-lead glass is changing.

When the PDP exhaust pipe is hermetically sealed, a local heat sealing means using a fixed gas burner, an energizing heater or the like is used. A sealing method using this local heating sealing means has been widely used conventionally, and the closed sealing planned portion of the fixed exhaust pipe is locally heated by a fixed gas burner or a current heater, melted, and melted. (For example, refer patent document 5 etc.). Conventionally, the tip tube used for exhausting the PDP and sealing the exhaust part is a glass tube containing lead and having a relatively low melting point and a thick glass tube. In the attaching process, it is common to use a process in which a thick tip tube is sealed by electrothermal sealing, and a thin tip tube is sealed using a fixed gas burner.
JP 2002-053342 A JP 2001-045875 A JP-A-9-050769 JP 2003-095597 A JP 7-057637 A

  However, as described above, when the sealing portion of the tip tube is simply heated to melt and seal the tip tube, FIG. 6A shows a longitudinal sectional view thereof, and FIG. As shown in another vertical cross-sectional view in a plane orthogonal to the cross section of a), in the melting part, that is, the sealing part 22, the negative pressure in the tip pipe that is reduced to a pressure lower than the atmospheric pressure causes the tip pipe to The glass wall in the heat-melted or softened state at the sealing portion is drawn so as to bulge in the tube axis direction toward the connecting portion side with the PDP panel of the tip tube 21 immediately before the sealing. In this case, the pull-in and the surface tension do not show rotational symmetry with respect to the tube axis of the tip tube, but deviate significantly from this symmetry, and an extreme meat reservoir 23 is produced in part or accompanied by extremes. A thin thin concave portion 24 may be generated.

  When a thick tip tube made of a relatively soft glass containing lead is used as in the conventional case, a wall 23 or an extremely thin concave portion 24 is generated in the sealing portion, or extremely axial symmetry. Is prevented, and the reliability of sealing is not a big problem.

  In addition, when lead-free glass is used for the exhaust pipe in consideration of the environment, the softening point of borosilicate glass that does not contain lead rises. The means is often an electrothermal sealing by heating an energized heater. Electrothermal sealing is superior in that the control of the heating temperature is relatively accurate, easy to handle during mass production, and easy to automate, but the heating part (electric heater) is larger than the method using a fixed gas burner. Also, the time required for heating and cooling becomes long, and it is not easy to increase the manufacturing tact. For this reason, even when a lead-free exhaust pipe is used and a sealing operation is performed with a fixed gas burner, a thin and hard glass chip tip pipe is used.

  However, when a chip tube made of a thin and hard glass tube is used, if the occurrence of the above-described reservoir 23 or thin bent portion (recessed portion 24 or bulging portion 25) occurs significantly, good sealing is hindered. Not only that, but due to the occurrence of distortion due to this, for example, the stress in the cooling process becomes large, cracks occur in the sealing portion 22 and the vicinity thereof, and the display device becomes defective, and reliability such as a reduction in life after commercialization It became a problem to be solved.

  The present invention solves the above-described problems, and in a PDP that forms an extremely narrow space such as a discharge space, the coefficient of thermal expansion is small, that is, it is made of hard glass and is thin, and is made of lead-free glass. Even when the chip tube is sealed with a fixed gas burner, an object is to realize a PDP that does not have a decrease in reliability due to a failure of a sealing portion such as a crack or a leak.

  In order to achieve the above object, the PDP according to the present invention has a front plate and a back plate facing each other and seals the periphery of both substrates to form a discharge space, exhausts the discharge space, and discharges into the discharge space. A PDP having a tubular exhaust pipe that encloses gas, wherein the exhaust pipe is formed of a material not containing lead, and the ratio of the thickness of the exhaust pipe to the outer diameter of the exhaust pipe is 0.18 or less. It has a configuration. The PDP according to the present invention has not only a structure in which the exhaust pipe is formed using borosilicate glass not containing lead, but when the outer diameter of the exhaust pipe is 5 mm, the thickness of the exhaust pipe is 0. You may have the structure which exists in the range of 0.4 mm or more and less than 0.9 mm.

  With these configurations, lead-free borosilicate glass is used for the PDP exhaust pipe, and the ratio of the wall thickness to the outer diameter is defined as 0.18 (the nominal outer diameter is 5.0 mmφ and the wall thickness is less than 0.9 mm) ), The glass thickness of the sealing portion can be formed uniformly, and a strong sealing portion free from residual stress due to thermal strain can be formed in the sealing portion. It is possible to realize a highly reliable PDP that does not generate cracks. Further, since an exhaust pipe made of borosilicate glass not containing lead is used, it is possible to realize lead-free PDP as a whole and to realize an excellent PDP capable of eliminating adverse effects on the environment. .

  According to the PDP and the manufacturing method thereof of the present invention, even when a thin, non-lead glass chip tube made of hard borosilicate glass is sealed with a fixed gas burner, the coefficient of thermal expansion is small. There is no decrease in reliability due to the failure of the sealing portion, and it is possible to increase the manufacturing tact and reduce the man-hours to realize a high-quality and inexpensive PDP.

  Hereinafter, a PDP according to an embodiment of the present invention will be described in detail with reference to the drawings.

(Embodiment)
FIG. 1 is a perspective view showing the structure of a PDP in an embodiment of the present invention. The basic structure of the PDP is the same as that of a general AC surface discharge type PDP. As shown in FIG. 1, the PDP 1 has a front plate 2 made of a front glass substrate 3 and a back plate 10 made of a back glass substrate 11 facing each other, and its outer peripheral portion is sealed with a glass frit or the like. The material is hermetically sealed. A discharge gas such as neon (Ne) and xenon (Xe) is sealed at a pressure of 400 Torr to 600 Torr in the discharge space 16 inside the sealed PDP 1.

  On the front glass substrate 3 of the front plate 2, a pair of strip-like display electrodes 6 made up of scanning electrodes 4 and sustain electrodes 5 and black stripes (light-shielding layers) 7 are arranged in a plurality of rows in parallel with each other. A dielectric layer 8 serving as a capacitor is formed on the front glass substrate 3 so as to cover the display electrode 6 and the light shielding layer 7, and a protective layer 9 made of magnesium oxide (MgO) is formed on the surface. Has been.

  On the back glass substrate 11 of the back plate 10, a plurality of strip-like address electrodes 12 are arranged in parallel to each other in a direction orthogonal to the scanning electrodes 4 and the sustain electrodes 5 of the front plate 2. Layer 13 is covering. Further, a partition wall 14 having a predetermined height is formed on the base dielectric layer 13 between the address electrodes 12 to divide the discharge space 16. For each address electrode 12, a phosphor layer 15 that emits red, blue, and green light by ultraviolet rays is sequentially applied to the grooves between the barrier ribs 14 and formed. A discharge cell is formed at a position where the scan electrode 4 and the sustain electrode 5 intersect with the address electrode 12, and the discharge cell having red, blue and green phosphor layers 15 arranged in the direction of the display electrode 6 is used for color display. Become a pixel.

FIG. 2 is a cross-sectional view of front plate 2 showing the configuration of dielectric layer 8 of the PDP in the embodiment of the present invention. FIG. 2 is shown upside down from FIG. As shown in FIG. 2, display electrodes 6 and black stripes 7 made of scanning electrodes 4 and sustain electrodes 5 are formed in a pattern on a front glass substrate 3 manufactured by a float process or the like. Scan electrode 4 and sustain electrode 5 are made of transparent electrodes 4a and 5a made of indium tin oxide (ITO), tin oxide (SnO ₂ ), and the like, and metal bus electrodes 4b and 5b formed on transparent electrodes 4a and 5a, respectively. It is comprised by. The metal bus electrodes 4b and 5b are used for the purpose of imparting conductivity in the longitudinal direction of the transparent electrodes 4a and 5a, and are formed of a conductive material mainly composed of a silver material.

  Next, a method for manufacturing a PDP will be described. First, the scan electrode 4, the sustain electrode 5, and the light shielding layer 7 are formed on the front glass substrate 3. The transparent electrodes 4a and 5a and the metal bus electrodes 4b and 5b constituting the scan electrode 4 and the sustain electrode 5 are formed by patterning using a photolithography method or the like. The transparent electrodes 4a and 5a are formed using a thin film process or the like, and the metal bus electrodes 4b and 5b are solidified by baking a paste containing a silver material at a desired temperature. Similarly, the light shielding layer 7 is also formed by screen printing a paste containing a black pigment or by forming a black pigment on the entire surface of the glass substrate and then patterning and baking using a photolithography method.

  Next, a dielectric paste is applied on the front glass substrate 3 by a die coating method or the like so as to cover the scan electrode 4, the sustain electrode 5, and the light shielding layer 7, thereby forming a dielectric paste layer (dielectric material layer). After the dielectric paste is applied, the surface of the applied dielectric paste is leveled by leaving it to stand for a predetermined time, so that a flat surface is obtained. Thereafter, the dielectric paste layer is baked and solidified to form the dielectric layer 8 that covers the scan electrode 4, the sustain electrode 5, and the light shielding layer 7. The dielectric paste is a paint containing a dielectric material such as glass powder, a binder and a solvent. Next, a protective layer 9 made of magnesium oxide (MgO) is formed on the dielectric layer 8 by a vacuum deposition method. Through the above steps, predetermined components (scanning electrode 4, sustaining electrode 5, light shielding layer 7, dielectric layer 8, and protective layer 9) are formed on front glass substrate 3, and front plate 2 is completed.

  On the other hand, the back plate 10 is formed as follows. First, a structure for the address electrode 12 is obtained by a method of screen printing a paste containing a silver material on the back glass substrate 11 or a method of forming a metal film on the entire surface and then patterning using a photolithography method. An address electrode 12 is formed by forming a material layer and firing it at a desired temperature.

  Next, a dielectric paste is applied on the rear glass substrate 11 on which the address electrodes 12 are formed by a die coating method so as to cover the address electrodes 12 to form a dielectric paste layer. Thereafter, the base dielectric layer 13 is formed by firing the dielectric paste layer. The dielectric paste is a paint containing a dielectric material such as glass powder, a binder and a solvent.

  Next, a partition wall forming paste including a partition wall material is applied on the base dielectric layer 13 and patterned into a predetermined shape to form a partition wall material layer and then fired to form the partition walls 14. Here, as a method of patterning the partition wall paste applied on the base dielectric layer 13, a photolithography method or a sand blast method can be used.

  Next, the phosphor layer 15 is formed by applying and baking a phosphor paste containing a phosphor material on the base dielectric layer 13 between the adjacent barrier ribs 14 and on the side surfaces of the barrier ribs 14. Through the above steps, the back plate 10 having predetermined components on the back glass substrate 11 is completed.

  FIG. 3 is a view showing a state in which the front plate and the back plate of the PDP in the embodiment of the present invention are sealed and joined, and the periphery of the front plate 2 and the back plate 10 is sealed with a sealing material 31. And the structure which provided the exhaust pipe 21 in the backplate 10 is shown. FIG. 3A is a plan view of the PDP according to the embodiment of the present invention, and FIG. 3B is a cross-sectional view taken along the line AA of the PDP shown in FIG.

  As shown in FIG. 3, the front plate 2 and the back plate 10 are arranged to face each other so that the display electrodes 6 and the address electrodes 12 are orthogonal to each other, and are provided around the corners of the back plate 10 and at predetermined positions. After the periphery of the widened end portion of the exhaust pipe 21 arranged so as to cover the exhaust pores 30 is sealed with sealing materials 31 and 32 such as glass frit and the discharge space 16 is evacuated by the exhaust pipe 21 Similarly, a discharge gas containing neon (Ne), xenon (Xe) or the like is sealed from the exhaust pipe 21 at a predetermined pressure (for example, a pressure of 400 Torr to 600 Torr in the case of a Ne—Xe mixed gas), and the exhaust pipe 21 is sealed. Thus, the PDP 1 is completed. For sealing the exhaust pipe 21, a sintered sealing material 32 called a tablet having a hole in the center is used.

  When sealing the exhaust pipe, a local heating sealing means using a fixed gas burner or an energizing heater is used. However, the electrothermal sealing using an energizing heater or the like can control the heating temperature relatively accurately, and can be used during mass production. Although it is easy to handle and easy to automate, the heating part (energized heater) is larger than the method using a fixed gas burner, and the time required for heating and cooling is increased, making it easier to increase manufacturing tact. For this reason, in the embodiment of the present invention, the sealing operation of the exhaust pipe is performed using a fixed gas burner. In the process of sealing the exhaust pipe 21 of the PDP in the embodiment of the present invention, the process is performed by heating, melting, and fusing the scheduled closing portion of the fixed exhaust pipe 21.

  Here, the sealing step for sealing the exhaust pipe 21 and the exhaust pipe 21 will be described with reference to FIGS. 4 and 5. FIG. 4A is a cross-sectional view showing a state in which the PDP with the exhaust pipe attached thereto according to the embodiment of the present invention is attached to the exhaust head for exhaust, discharge gas sealing, and sealing, and FIG. BB sectional drawing in 4 (a), FIG. 5 (a)-FIG.5 (c) are sectional drawings explaining the procedure in the case of sealing the exhaust pipe of PDP in embodiment of this invention.

  In FIG. 4, the exhaust pipe 21 disposed and sealed so as to cover the exhaust pores 30 provided at predetermined positions near the corner portion of the back plate 10 of the PDP 1 has a funnel-like shape with one end widened. And is formed in a straight tube having an outer diameter of about 5.0 mmφ on the other end side. The exhaust pipe 21 in the embodiment of the present invention is made of borosilicate glass that does not contain a lead component and has a relatively low thermal conductivity. The exhaust pipe was formed using lead-free alkali borosilicate glass (product name “FE-2”) manufactured by Nippon Electric Glass Co., Ltd. Strictly speaking, the lead-free alkali borosilicate glass “FE-2” does not contain lead at all, and when analyzed, a trace amount of lead is detected at the PPM level. However, the EC-RoHS directive in Europe can be regarded as not containing lead if it is 1000 PPM or less, and in the embodiment of the present invention, expressions such as “does not contain lead” or “non-lead” are used. Yes.

  First, the sealed PDP 1 is installed in a device for exhaust, discharge gas introduction, and sealing so that the other end of the straight pipe of the exhaust pipe 21 faces downward. An exhaust head 41 of a device for exhaust, discharge gas introduction, and sealing is attached to the other end of the straight pipe of the exhaust pipe 21, and the interior including the discharge space of the PDP is exhausted in a furnace at a predetermined temperature to generate discharge gas. After being sealed, a fixed gas burner 43 that is cooled and can heat the outer periphery of the sealing portion 21a of the exhaust pipe 21 is disposed. The exhaust head 41 is provided with a biasing means 42 using a spring or the like so that a load due to tension is applied to the exhaust pipe 21 downward (in the direction indicated by arrow C in FIG. 4A). Further, the heating flame 44 of the fixed gas burner 43 preferably has a configuration in which a plurality of flames are formed horizontally in a plane perpendicular to the exhaust pipe 21 as shown in FIG.

  When the outer periphery of the sealing portion 21a of the exhaust pipe 21 is heated to a predetermined temperature by the heating flame 44 of the fixed gas burner 43, the glass softens and the exhaust pipe 21 communicates with the discharge space as shown in FIG. In addition, a reduced portion 21b is formed in which the upper and lower portions of the planned sealing portion 21a are elongated by the tensile load by the urging means 42 and the inside is in a reduced pressure state. Further, when the reduced portion 21b of the exhaust pipe 21 is continuously heated by the heating flame 44 of the fixed gas burner 43, the inner surface of the exhaust pipe 21 comes into contact as shown in FIG. As a result, the glass is in a uniform molten state. Thereafter, the melt-bonded portion 21c further extends and narrows, and is finally cut. However, the end portion has a curved surface due to the surface tension of the molten glass, and a projecting sealing portion 21d is formed to form the exhaust pipe 21. Sealing is completed.

  When some of the sealing portions 21d of the PDP 1 provided with the exhaust pipe 21 made of borosilicate glass not containing lead are sampled and observed, the meat of the glass near the sealing portion 21d as shown in FIG. As in the case of the exhaust pipe 21 made of borosilicate glass containing lead shown in FIG. 6 and the conventional lead-containing borosilicate glass shown in FIG. Some of them have a sealing portion 21d having an extremely thin thickness and an uneven thickness. When these PDPs 1 were subjected to a repeated cooling and heating test, there was no problem if the glass thickness of the sealing portion 21d of the exhaust pipe 21 was sealed in a substantially uniform shape as shown in FIG. 5 (c). On the other hand, when the sealing portion 21d of the exhaust pipe 21 is unevenly thick and has the sealing portion 21d having an extremely thin portion, there are many cases where the leakage portion or cracks break and are damaged. Examination of the measurement data of the thickness and outer diameter of the exhaust pipe of these PDP 1 revealed that good and defective products were classified by the thickness of the exhaust pipe 21. In the exhaust pipe 21 having a nominal outer diameter of 5.0 mmφ, the wall thickness was distributed in the range of 0.85 mm to 1.1 mm. However, when the wall thickness is less than 0.9 mm (the inner diameter is larger than 3.2 mm). As shown in FIG. 5C, the glass thickness of the sealing portion 21d of the exhaust pipe 21 is sealed in a substantially uniform shape, and there was no abnormality even in the repeated cooling and heating test. However, in the exhaust pipe 21 having a nominal outer diameter of 5.0 mmφ having a wall thickness of 0.9 mm or more (inner diameter is 3.2 mm or less), the glass of the sealing portion 21d of the exhaust pipe 21 as shown in FIG. Some parts are sealed in a substantially uniform shape and have no abnormalities in the repeated cooling and heating test, but the thickness is not uniform in the state where the reservoir or the thickness is extremely thin as shown in FIG. There are some which have a sealing portion 21d and become defective in the repeated cooling and heating test. In the case of a sealing portion having a substantially uniform thickness of glass as shown in FIG. 5 (c), there is no distortion in the sealing portion, but the wall or thickness as shown in FIG. This indicates that there is distortion due to residual stress in the sealed portion 21d sealed in an uneven thickness in an extremely thin state.

  Therefore, a lead-free borosilicate glass system having a nominal outer diameter of 5.0 mmφ and a thickness of 0.7 mm, 0.8 mm, 0.85 mm, 0.9 mm, 0.95 mm, 1.0 mm, 1.1 mm 7 Different types of PDP exhaust pipes were prepared, PDP samples in which the exhaust pipes were sealed by the above-described sealing process were prepared, and the appearance inspection of the sealing portion and the cooling / heating repetition test were performed. The shape of the sealing part of the PDP using the exhaust pipes with wall thicknesses of 0.70 mm, 0.8 mm, and 0.85 mm is all sealed in a substantially uniform shape as shown in FIG. There was no problem even in the repeated heating and cooling test. On the other hand, in the PDP using the exhaust pipe having a wall thickness of 0.9 mm, 0.95 mm, 1.0 mm, and 1.1 mm, the wall accumulation and the wall thickness as shown in FIG. Those with thick sealing parts increase as the thickness of the exhaust pipe increases, and those with non-uniform thicknesses even in repeated heating and cooling tests cause defects such as leaks and cracks. There was a tendency to become prominent as the wall thickness increased.

  From the above results, when sealing with a fixed gas burner using a lead-free borosilicate glass PDP exhaust pipe with a nominal outer diameter of 5.0 mmφ, the thickness of the exhaust pipe should be less than 0.9 mm. By doing so, it can be said that the sealing portion is formed to have a uniform thickness, and no defects such as leakage or cracking of the sealing portion occur. However, even when a PDP exhaust pipe having a nominal outer diameter of 5.0 mmφ is used, if the wall thickness is smaller than 0.4 mm (the inner diameter is larger than 4.2 mm), the wall thickness is too thin and the sealing process is performed. Thus, it is confirmed that a leak occurs due to the glass tube being broken or a small hole is formed, and it is essential that the wall thickness is 0.4 mm or more.

  Subsequently, when sealing with a fixed gas burner using a borosilicate glass-based PDP exhaust pipe 21 having a nominal outer diameter different from 5.0 mmφ and containing no lead, The shape of 21d and the results of the repeated cooling test will be described.

  The prepared exhaust pipe 21 has four types of nominal outer diameters of 3.0 mmφ, 4.0 mmφ, 6.0 mmφ, and 7.0 mmφ. A sample in which the exhaust pipe was sealed by the above-described sealing process using these exhaust pipes was produced, and an appearance inspection and a repeated cooling test were performed on the sealed portion. In the case of an exhaust pipe having a nominal outer diameter of 5.0 mmφ, the exhaust pipe having a wall thickness of less than 0.9 mm with a wall thickness of 0.9 mm as a boundary, almost all of the sealing portion as shown in FIG. The glass wall was sealed in a substantially uniform shape, and there were no defects such as leaks or cracks in the repeated heating and cooling test. It became clear that there was thickness.

  That is, from the measured thickness of each exhaust pipe, the thickness of the exhaust pipe having a nominal outer diameter of 3.0 mmφ is 0.54 mm, the thickness of the exhaust pipe having a nominal outer diameter of 4.0 mmφ is 0.72 mm, and the nominal outer diameter is 6.0 mmφ. In the exhaust pipe, the wall thickness is 1.08 mm, and in the exhaust pipe having a nominal outer diameter of 7.0 mmφ, the wall thickness is 1.26 mm. From these results, it was found that the ratio of the wall thickness to the outer diameter of the exhaust pipe was 0.18, which was constant regardless of the nominal outer diameter value. Therefore, the relationship can be generalized by defining the exhaust pipe thickness / exhaust pipe outer diameter = 0.18 instead of the numerical values of the outer diameter and the thickness of the exhaust pipe.

  As described above, in the PDP according to the embodiment of the present invention, the ratio of the thickness of the exhaust pipe made of borosilicate glass containing no lead to its outer diameter is defined as 0.18 (nominal outer diameter of 5. Since the thickness is less than 0.9 mm at 0 mmφ, the glass thickness of the sealing portion can be uniformly formed even if sealing with a fixed gas burner is performed, and there is no residual stress due to thermal strain in the sealing portion. A strong sealing portion can be formed, and a highly reliable PDP that does not cause leakage or cracks in the sealing portion can be realized. Further, since an exhaust pipe made of borosilicate glass not containing lead is used, it is possible to realize lead-free PDP as a whole and to eliminate adverse effects on the environment. Furthermore, since sealing with a fixed gas burner is possible, the time required for heating and cooling the sealing portion can be shortened without reducing the size of the device as in electrothermal sealing, and the number of man-hours in the sealing process can be reduced. It is possible to reduce the manufacturing cost of the PDP and provide an inexpensive display device.

  In the present invention, the ratio of the thickness of the exhaust pipe made of borosilicate glass containing no lead to its outer diameter is defined as 0.18. Therefore, even if sealing with a fixed gas burner is performed, the sealing portion The glass thickness can be formed uniformly, and it is highly reliable and does not cause defects such as leaks and cracks in the sealing part. It is effective when applied to a large screen display device by realizing a PDP suitable for the environment. Is big.

The perspective view which shows the structure of PDP in embodiment of this invention Sectional drawing of the front plate which shows the structure of the dielectric material layer of PDP in embodiment of this invention The figure which shows the state which sealed and joined the front plate and back plate of PDP in embodiment of this invention. (A) is sectional drawing which shows the state which attached to the exhaust head in order to exhaust, discharge gas sealing, and sealing the PDP which attached the exhaust pipe in embodiment of this invention (b) is B- in (a). B line cross section (A)-(c) is sectional drawing explaining the procedure in the case of sealing the exhaust pipe of PDP in embodiment of this invention (A) is a longitudinal sectional view of a sealing portion of a conventional PDP chip tube, (b) is another longitudinal sectional view in a plane orthogonal to the section of (a).

Explanation of symbols

1 PDP
2 Front plate 3 Front glass substrate 4 Scan electrode 4a, 5a Transparent electrode 4b, 5b Metal bus electrode 5 Sustain electrode 6 Display electrode 7 Black stripe (light shielding layer)
8 Dielectric layer 9 Protective layer 10 Back plate 11 Back glass substrate 12 Address electrode 13 Base dielectric layer 14 Partition 15 Phosphor layer 16 Discharge space 21 Exhaust tube (chip tube)
21a Sealed portion 21b Reduced portion 21c Melt bonded portion 21d, 22 Sealed portion 23 Meat pool 24 Recessed portion 25 Expanded portion 30 Exhaust pores 31, 32 Sealing material 41 Exhaust head 42 Energizing means 43 Fixed gas burner 44 Heating flame

Claims (1)

A plasma having a tubular exhaust pipe in which a front plate and a back plate are arranged to face each other and the periphery of both substrates is sealed to form a discharge space, the discharge space is exhausted, and discharge gas is sealed in the discharge space. A display panel,
The exhaust pipe is formed of a material not containing lead, and the ratio of the thickness of the exhaust pipe to the outer diameter of the exhaust pipe is 0.18 or less ,
The exhaust pipe is formed using borosilicate glass containing no lead.
When the outer diameter of the exhaust pipe is 5 mm, the thickness of the exhaust pipe is in the range of 0.4 mm or more and less than 0.9 mm .