JP2009224095A - Manufacturing method of plasma display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a PDP, capable of substantially reducing occurrence of failures in a sealed portion such as cracks and leakage when sealing a tip pipe of non-lead glass by using a stationary gas burner. <P>SOLUTION: In this manufacturing method of the plasma display panel 1 in which a front plate 2 and a back plate 10 are facingly disposed forming a discharge space 16, and an exhaust pipe 21 is provided in the back plate 2, the exhaust pipe 21 is formed of a glass material containing no lead, and when sealing the exhaust pipe 21, a predetermined portion 21a to be sealed in the exhaust pipe 21 is heated by the stationary gas burner 43, the exhaust pipe 21 is extended and fused when the temperature of the exhaust pipe 21 is in the temperature range exceeding its softening point temperature by 20-50°, and the thickness of the sealed portion 21d is thereby set within a range of 0.3-0.9 of the thickness of the tip pipe portion which has not been heated. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a plasma display panel (hereinafter referred to as PDP) which is a flat display device used for large televisions, public displays, and the like.

  In recent years, gas discharge panels typified by PDPs have attracted attention as thin display devices with excellent visibility, and have become popular in homes in terms of high definition, large screens, and ease of manufacturing. It is out.

  The PDP has a configuration in which a front plate and a back plate are arranged to face each other so as to form a discharge space therebetween. The front plate is a glass substrate made of sodium borosilicate glass by a float method, a display electrode composed of a striped transparent electrode and a metal bus electrode formed on one main surface, and the display electrode A dielectric layer that covers and acts 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), stripe-shaped address electrodes formed on one main surface thereof, and underlying dielectric covering the address electrodes. A body layer, partition walls formed on the base dielectric layer, and phosphor layers emitting red, green and blue light respectively formed between the partition walls.

  The front plate and the back plate are opposed to each other on the electrode forming surface side, and the exhaust pipe for exhausting the discharge space and introducing the discharge gas into the discharge space and the discharge space. However, the discharge space exhausted and sealed with a partition wall and sealed with a partition wall is filled with discharge gas (pressure of 400 Torr to 600 Torr in the case of Ne-Xe) through the tip tube. The tip tube is locally heated and melted (tip-off) at an appropriate location and hermetically sealed.

  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.

  In addition, low-melting glass mainly composed of lead oxide has been used for the PDP dielectric layer and sealing material described above, but it does not contain a lead component in consideration of recent environmental problems. Lead-free materials called “lead-free” and “lead-free” are used.

  Furthermore, the conventional tip tube is 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 chip tube 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 so far, and a portion to be sealed of a fixed chip tube is locally heated by a fixed gas burner or a current heater, melted, and melted. (For example, refer to Patent Document 1).
JP 7-057637 A

  However, the configuration using the energizing heater disclosed in Patent Document 1 is excellent in that the control of the heating temperature is relatively accurate, easy to handle during mass production, and easy to automate, but uses a fixed gas burner. The problem is that the heating part (energizing heater) becomes larger than that of the method, and the time required for heating and cooling becomes longer, making it difficult to increase the manufacturing tact.

  Therefore, in sealing a chip tube made of a lead-free material, as disclosed in Patent Document 1, a method of simply melting and sealing a chip tube by heating a planned sealing portion of the chip tube with a fixed gas burner. Is applied, the sealing portion is in a state as shown in FIG. Here, FIG. 6 is a diagram schematically showing the state of the sealing portion, FIG. 6A is a longitudinal sectional view of the sealing portion of the chip tube, and FIG. 6B is shown in FIG. 1 schematically shows a longitudinal sectional view rotated 90 degrees from the longitudinal sectional view.

  As shown in FIG. 6, when a fixed gas burner is used to seal a tip tube made of a lead-free material, the sealing portion 22 that has been heated and melted or softened is heated and melted or softened. The glass wall of the sealing portion 22 is drawn so as to bulge in the direction of the tube axis toward the connecting portion side with the PDP in the tip tube 21 having a negative pressure with respect to the atmospheric pressure. However, it does not show rotational symmetry with respect to the tube axis of the tip tube 21, and as a result, an extremely thick portion 23 and extremely thin bent portions 24 and 25 are generated. When such an extremely thick portion 23 and extremely thin bent portions 24 and 25 are present, not only good and stable sealing is hindered, but also distortion occurs at that location, Cracks occur in the sealing portion 22 and the vicinity thereof, causing a problem such as causing the plasma display panel to be defective or reducing the life after commercialization.

  The present invention has been made in view of such a situation, and in the case of sealing a non-lead glass chip tube using a fixed gas burner, the occurrence of defects in the sealing portion such as cracks and leaks is greatly increased. An object of the present invention is to realize a method for manufacturing a PDP that can be reduced.

  In order to achieve the above object, in the method of manufacturing a plasma display panel according to the present invention, a front plate and a back plate are arranged to face each other so as to form a discharge space therein, and the back plate is provided with exhaust and discharge space. A method of manufacturing a plasma display panel including an exhaust pipe for sealing discharge gas, wherein the exhaust pipe is formed of a lead-free glass material, and the exhaust pipe is sealed when the exhaust pipe is sealed. The part to be stopped is heated with a fixed gas burner, and when the temperature of the exhaust pipe is in the temperature range of 20 to 50 ° C. higher than its softening point temperature, the exhaust pipe is stretched and melted to heat the thickness of the sealing part. It is set to a range of 0.3 to 0.9 with respect to the thickness of the tip tube portion that is not.

  According to the PDP manufacturing method of the present invention, when a non-lead glass chip tube is sealed by using a fixed gas burner, it is possible to greatly reduce the occurrence of defects in the sealing portion such as cracks and leaks. A method for manufacturing a PDP can be realized.

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

  FIG. 1 is a cross-sectional perspective view showing a schematic structure of a PDP manufactured by manufacturing a PDP according to an embodiment of the present invention. As shown in FIG. 1, the PDP 1 is disposed so that the front plate 2 and the back plate 10 face each other so as to form a discharge space 16, and the outer periphery thereof is hermetically sealed with a sealing material made of glass frit or the like. It is worn. The discharge space 16 inside the sealed PDP 1 is filled with a discharge gas such as neon (Ne) and xenon (Xe) at a pressure of 400 Torr to 600 Torr.

  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 is formed 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 so as to cover the dielectric layer 8.

  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 intersecting with the scanning electrodes 4 and the sustain electrodes 5 of the front plate 2. 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 showing a schematic configuration of the front plate 2 of the PDP 1 manufactured by the PDP manufacturing method according to the embodiment of the present invention. 2 shows the front plate 2 shown in FIG. 1 upside down. 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 diagram schematically showing a state in which the front plate 2 and the rear plate 10 are sealed in the PDP 1 manufactured by the method for manufacturing a PDP according to the embodiment of the present invention. 10 is shown in which the periphery is sealed with a sealing material 31 and a chip tube 21 is provided on the back plate 10. 3A is a schematic plan view of the PDP 1, and FIG. 3B is a cross-sectional view 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 (FIG. 1) and the address electrodes 12 (FIG. 2) intersect with each other. The tip tube 21 arranged so as to cover the tip tube pore 30 provided at a predetermined position of the corner portion is sealed around the expanded end portion with sealing materials 31 and 32 such as glass frit, and the discharge space. 16 is evacuated through the tip tube 21 and then discharge gas containing neon, xenon, etc. from the tip tube 21 to the discharge space 16 at a predetermined pressure (for example, a pressure of 400 Torr to 600 Torr in the case of Ne—Xe mixed gas). The PDP 1 is completed by sealing and then sealing the chip tube 21 (chip off). When joining the tip tube 21 to the back glass substrate 11 of the back plate 10, the amount of sealing material was sintered in a ring shape so as to have a hole through which the tip tube 21 passes in the center. A sealing material 32 is used.

  Further, when the tip tube 21 is sealed (chip off), a fixed gas burner is used to heat, melt and melt the portion to be sealed of the tip tube 21. The sealing process of the chip tube 21 will be described with reference to FIG. FIG. 4 is a diagram schematically showing the sealing step of the tip tube 21 in the method for manufacturing a PDP according to the embodiment of the present invention.

  4A schematically shows a state in which the fixed gas burner 43 and the exhaust head 41 are installed on the tip tube 21 fixed to the PDP 1 with the sealing material 32, and FIG. 4B shows the state shown in FIG. FIG. 4C is a cross-sectional view taken along line B-B in FIG. 4A, and FIG. 4C to FIG.

  As shown in FIG. 4 (a), one end of the tip tube 21 that is arranged and sealed so as to cover the exhaust pore 30 provided at a predetermined position near the corner portion of the back plate 10 of the PDP 1 is expanded. The other end side is formed in a straight tube shape having an outer diameter of about 5.0 mmφ and a thickness of 0.90 mm or more and less than 1.10 mm. Moreover, as the component, what is called non-lead and lead-less is comprised with the borosilicate type glass which does not contain a lead component.

  First, the PDP 1 is installed in the exhaust and discharge gas introduction device so that the end portion of the tip tube 21 on the straight tubular side faces downward. Then, an exhaust head 41 of an exhaust and discharge gas introducing device is attached to the end portion of the tip tube 21 on the straight tubular side, and a fixed gas burner is provided so that the outer periphery of the sealing portion 21a of the tip tube 21 can be heated. 43 is arranged. In this state, the inside of the discharge space 16 of the PDP 1 is evacuated, and then the discharge gas is introduced (sealed) into the discharge space 16, and then the outer periphery of the sealing portion 21 a of the tip tube 21 is heated by the heating flame 44 from the fixed gas burner 43. Heat.

  A force is applied to the exhaust head 41 so that the exhaust head 41 is displaced downward with respect to the tip tube 21 (the direction indicated by the arrow C in FIG. 4A), that is, in a direction in which the tip tube 21 is extended. Is configured to do. Specifically, for example, an urging means 42 using a spring or the like is provided.

  The heating flame 44 of the fixed gas burner 43 is preferably configured such that a plurality of horizontal flames are formed in the cross section of the tip tube 21 as shown in FIG.

  Further, as shown in FIG. 4B, a temperature observation device 45 (for example, an infrared thermoviewer) is provided so that the temperature at the time of sealing of the tip tube 21 can be observed horizontally with the planned sealing portion 21a of the tip tube 21. Is provided.

  When heating the outer periphery of the sealing target portion 21a of the tip tube 21 with the heating flame 44 of the fixed gas burner 43, the temperature observation device 45 always observes the temperature of the sealing target portion 21a and the heated tip tube 21 of the tip tube 21 is heated. When the sealing target portion 21a exceeds the glass softening point of the tip tube 21, the exhaust head 41 is pulled by the urging means 42. As a result, the tip tube 21 extends and becomes thin as shown in FIG. A reduced portion 21b is formed.

  Further, when the reduced portion 21b of the tip tube 21 is continuously heated by the heating flame 44 of the fixed gas burner 43, as shown in FIG. 4 (d), the inner wall of the planned sealing portion 21a of the tip tube 21 comes into contact with the melt bonded portion. 21c is formed and is in a uniform molten state.

  Thereafter, the melt-bonded portion 21c is further extended and thinned, and finally cut (fused). However, a protruding sealing portion 21d having a curved end portion is formed by the surface tension of the molten glass. Sealing of the tip tube 21 is completed.

  FIG. 5 shows a schematic diagram of the sealing portion 21d when the sealing is completed. The sealing portion 21d does not have an extremely thick portion or an extremely thin bent portion, and the thickness 21f of the sealing portion 21d can be made thinner than the thickness 21e of the unheated tip tube 21 portion.

  Here, the following knowledge was able to be acquired by examination of the present inventors. In other words, in the sealing step of the tip tube 21 shown in FIG. 4, an experiment was conducted on the relationship between the temperature of the tip tube 21 when the tip tube 21 was heated by the fixed gas burner 43 and the pulling condition of the exhaust head 41. Here, the pulling conditions of the exhaust head 41 include tension, pulling speed, and pulling stroke. Here, the tension is constant, the pulling speed is 10 to 50 mm / sec, and the pulling stroke is in the range of 20 to 50 mm. The experiment was conducted.

  As a result, it has been found that, under the above-described tension conditions, the tension cannot be started unless the sealing portion 21d of the tip tube 21 is heated to a temperature exceeding the softening point of the glass of the tip tube 21 by 10 ° C. or more. Further, when the tip tube 21 is heated to a temperature exceeding the softening point of 60 ° C. or more during pulling, the thickness of the sealing portion 21d of the tip tube 21 starts to be biased, and an extremely thick portion as shown in FIG. It was confirmed that an extremely thin bent portion started to occur. As described above, the sealing of the tip tube 21 is preferably completed while the tip tube 21 is in a temperature range 20 to 50 ° C. higher than the softening point of the tip tube 21.

  That is, when the sealing is completed in the above temperature range, an extremely thick part or an extremely thin bent part as shown in FIG. 5 does not occur, and the thickness 21f of the sealing part 21d is: The tip tube 21 that is not heated is thinner than the thickness 21e, and the ratio is in the range of 0.3 to 0.9 in the entire region of the sealing portion.

  It was confirmed that the sealing part having the dimensional relationship as described above did not cause a problem such as occurrence of leakage in the sealing part 21d even after the repeated cooling test.

  On the other hand, in the case of the sealing portion as shown in FIG. 6, there may be a problem that leakage occurs or, in an extreme case, a crack occurs and breaks.

  As described above, according to the method for manufacturing a PDP according to an embodiment of the present invention, the temperature at the time of sealing a chip tube made of borosilicate glass containing no lead is observed, and the sealing operation is controlled. In addition, by completing the sealing while the sealing portion of the chip tube is at a desired temperature, the glass thickness of the sealing portion can be uniformly formed even when sealing with a fixed gas burner, and Thus, it is possible to form a strong sealing portion free from residual stress due to thermal strain in the sealing portion, and to produce a PDP in which the occurrence of leakage and cracks in the sealing portion is significantly suppressed.

  In addition, since a tip tube 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.

  As described above, the present invention is useful for providing a large-screen, high-definition plasma display panel.

Sectional perspective view which shows schematic structure of PDP manufactured by the manufacturing method of PDP by one embodiment of this invention Sectional drawing which shows schematic structure of the front plate of PDP manufactured by the manufacturing method of PDP by one embodiment of this invention The figure which shows schematically the state which sealed the front board and the back board in PDP manufactured by the manufacturing method of PDP by one embodiment of this invention. The figure which shows typically the sealing process of the chip pipe | tube in the manufacturing method of PDP by one embodiment of this invention. Schematic of sealing part at the time of completion of sealing in a method for manufacturing a PDP according to an embodiment of the present invention Sectional drawing which shows schematically the sealing part of the tip pipe | tube in the conventional PDP

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, 11 Black stripe 8 Dielectric layer 9 Protective layer 10 Back plate 11 Rear 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 Sealed portion 21e, 21f Thickness 22 Sealed portion 23 Thick portion 24, 25 Thin bent portion 30 Exhaust pore 31, 32 Sealing material 41 Exhaust head 42 Energizing means 43 Fixed gas burner 44 Heating flame 45 Temperature observation device

Claims (1)

A method of manufacturing a plasma display panel in which a front plate and a back plate are disposed to face each other so as to form a discharge space therein, and the back plate includes an exhaust pipe for exhausting the discharge space and sealing discharge gas. There,
The exhaust pipe is formed of a lead-free glass material,
When sealing the exhaust pipe, the portion to be sealed of the exhaust pipe is heated with a fixed gas burner, and when the temperature of the exhaust pipe is in a temperature range 20 to 50 ° C. higher than the softening point temperature, the exhaust pipe is stretched and melted. The manufacturing method of the plasma display panel which makes the thickness of a sealing part the range of 0.3-0.9 with respect to the thickness of the chip tube part which is not heated.

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