WO2007111054A1

WO2007111054A1 - Display panel

Info

Publication number: WO2007111054A1
Application number: PCT/JP2007/052667
Authority: WO
Inventors: Ken Choju; Hironori Takase; Shinji Ohigashi
Original assignee: Nippon Electric Glass Co., Ltd.
Priority date: 2006-03-29
Filing date: 2007-02-15
Publication date: 2007-10-04
Also published as: CN101361155A; JP2007294395A; KR20080055969A; CN101361155B

Abstract

[PROBLEMS] To provide a display panel wherein substrate glasses are not warped when sealing the front substrate glass and the back substrate glass with a low melting point sealing glass, even when substrate glasses having a small substrate thickness and large sizes are used, and to contribute to screen size increase, fineness and weight reduction of a display panel. [MEANS FOR SOLVING PROBLEMS] In a display panel wherein a front substrate glass and a back substrate glass are airtightly sealed with a low melting point sealing glass, the substrate thicknesses of the front substrate glass and the back substrate glass are less than 2.8mm, and a difference between the thermal expansion coefficient of the front substrate glass and that of the back substrate glass is 2.0×10-7/°C or below.

Description

Specification

Display panel technology

The present invention relates to a display panel in which a front plate glass and a back plate glass are hermetically sealed via a low melting point sealing glass, and in particular, the front plate glass and the rear plate glass are hermetically sealed via a low melting point sealing glass. The present invention relates to a plasma display panel.

Background art

A plasma display panel (hereinafter referred to as “PDP”) has a structure in which a front plate glass and a back plate glass are bonded together via a low melting point sealing glass. The front plate glass is formed with a transparent electrode made of an ITO film, a nesa film or the like on its surface, and a dielectric layer is formed after the dielectric glass is applied thereon. Further, the back plate glass has electrodes made of Al, Ag, Ni, etc. formed on the surface thereof, and a barrier rib (also referred to as a barrier rib) is formed after dielectric glass and barrier rib material are applied thereon. Thereafter, the front plate glass and the rear plate glass are made to face each other and the electrodes and the like are aligned, and then the front plate glass and the rear plate glass are hermetically sealed using the low melting point sealing glass.

[0003] Conventionally, a flat glass for PDP (front panel glass and the back glass plate), use soda-lime glass which is widely used as or for automobiles Architecture (thermal expansion coefficient of about 84 X 10_ ⁷ / ° C) is Irare Other peripheral materials such as dielectric glass have been designed to meet this thermal expansion coefficient. However, because strained soda-lime glass has a strain point as low as about 500 ° C, thermal deformation and thermal shrinkage occur when heat treatment is performed at around 600 ° C. For this reason, when the front and rear glass plates made of soda-lime glass are opposed to each other, it is difficult to accurately align the electrodes and the like due to thermal deformation and thermal shrinkage. It was difficult. Therefore, as a plate glass for PDP, a glass having a thermal expansion coefficient similar to that of soda-lime glass and a high strain point has been put into practical use (see Patent Documents 1 and 2).

[0004] Even when high strain point glass is used for the plate glass, if the difference in thermal expansion coefficient between the plate glass and the dielectric layer is large, the plate glass is subjected to heat treatment for forming the dielectric layer. There was a problem that stress was applied and the glass sheet warped. If warpage occurs in the glass plate, the front plate When the glass and the back plate glass are hermetically sealed, the respective plate glasses are not parallel to each other, so that accurate alignment cannot be performed, making the hermetic seal difficult and causing problems such as cracking the plate glass. Yield was decreasing. According to Patent Document 3, even if warpage occurs in the plate glass, if the plate glass with the amount of warpage specified in the range of 1 X 10 ^_2 m ^{_ 1} ≤l / R ≤ 1 X ΙΟ ^ π ¹ is used, it is hermetically sealed. It is described that it is possible to suppress the breakage of the glass sheet during wearing and to improve the yield. Here, R is the curvature radius of the curvature of the glass sheet.

Patent Document 1: JP-A-8-290938

Patent Document 2: JP-A-8-290939

Patent Document 3: Japanese Patent Laid-Open No. 10-283941

Disclosure of the invention

Problems to be solved by the invention

[0005] In recent years, display panels, particularly PDPs, have been increasing in screen size and definition. When the screen size of the PDP increases, even if slight thermal deformation or shrinkage occurs in the plate glass during the PDP manufacturing process, the entire screen of the PDP appears as a large distortion. In addition, if the PDP with a large screen size is warped, a large gap will be created between the partition wall head inside the PDP and the front plate glass, and there is a risk of erroneous discharge between the cells. In this case, the image is curved and the surface quality of the PDP deteriorates when viewed from the display surface of the front plate glass. Furthermore, if the PDP warps after the front plate glass and the rear plate glass are hermetically sealed with the low-melting point sealing glass, the PDP is used for the vacuum exhaust, rare gas sealing, and exhaust pipe sealing processes that are provided thereafter. When P is added, the PDP easily shifts in a firing furnace such as a belt furnace, resulting in a decrease in the production yield of the PDP.

[0006] Further, there is a demand for weight reduction of the PDP, and if the thickness of the plate glass used for the PDP is reduced, it is possible to greatly contribute to the weight reduction of the PDP. Currently, the sheet glass used for PDP has a plate thickness of approximately 2.8 mm. However, if the sheet thickness is less than 2 Omm, for example, it will be possible to make a significant contribution to the overall light weight of the PDP. . However, if the plate thickness of the plate glass is reduced, the plate glass is likely to be thermally deformed or shrunk in the PDP manufacturing process, which causes the same problem as in the case of increasing the screen size. [0007] According to Patent Documents 1 and 2, when high strain point glass having a strain point of 570 ° C or higher is used as a plate glass, thermal deformation caused by the thermal properties (strain point, etc.) of the plate glass in the PDP manufacturing process. Shape and heat shrinkage can be suppressed. According to Patent Document 3, when the difference in coefficient of thermal expansion between the plate glass and the dielectric layer is set to an appropriate value, it is possible to suppress the warpage of the plate glass that occurs when the dielectric layer is formed on the plate glass. However, even when a high strain point glass having a strain point of 570 ° C or higher is used and the thermal expansion coefficient of the dielectric layer formed on the plate glass is set to an appropriate value, the thickness of the plate glass is small. When the size is large, when the front and rear glass plates are hermetically sealed with the low melting point sealing glass, the plate glass is greatly warped, which is a major obstacle to achieving a large screen, high definition and light weight. Become.

As described above, the present invention has been made in view of the above circumstances, and even when a plate glass having a small plate thickness and a large size is used, the front plate glass and the back plate glass are sealed with a low melting point. It is an object of the present invention to provide a display panel that does not warp the plate glass when hermetically sealing with the glass, and to contribute to achieving a large screen, high definition, and light weight of the display panel.

Means for solving the problem

As a result of various experiments, the present inventors have found that the front plate glass and the back plate glass are placed on the display panel in which the front plate glass and the back plate glass are hermetically sealed via the low melting point sealing glass. thickness of 2. less than 8 mm, and a thermal expansion coefficient difference of the back plate glass front plate glass 2. with less 0 X 10_ ⁷ Z ° C, can be obtained there is no warping display panel, the display The present inventors have found that a large screen, high definition, and light weight can be achieved for the panel, and propose the present invention.

[0010] A display panel in which a front plate glass and a rear plate glass are hermetically sealed via a low-melting point sealing glass, for example, a PDP has a gap (gap) between the front and rear plate glasses that is sealed with a low-melting point sealing glass. It corresponds to the thickness and has a very small value. In such a case, if the thermal expansion coefficients of the front plate glass and the rear plate glass are mismatched, the front plate glass and the rear plate glass are hermetically sealed with a low-melting-point sealing glass, and then concave on the side of the plate glass having a large thermal expansion coefficient. It became clear that warping occurred in the display panel due to this. In particular, if the thickness of the PDP front and back glass is less than 2.8 mm In other words, if the plate glass thickness is less than 2.8 mm, if the thermal expansion coefficients of the front plate glass and the rear plate glass are mismatched, the front plate glass and the rear plate glass are hermetically sealed with the low melting point sealing glass, It has been clarified that a concave warp tends to occur on the side of the plate glass having a large expansion coefficient.

[0011] Therefore, as a result of diligent efforts, the present inventors restricted the difference in thermal expansion coefficient between the front plate glass and the rear plate glass to 2. OX 10_ ⁷ / ° C or less when the plate glass thickness is less than 2.8 mm. Then, after the front plate glass and the back plate glass were hermetically sealed with the low melting point sealing glass, it was found that a situation in which a concave warp occurs on the side of the plate glass having a large thermal expansion coefficient can be suppressed.

[0012] As a method for regulating the thermal expansion coefficient difference of the back plate glass front plate glass 2. below 0 X 10_ ⁷ / ° C, the various methods are conceivable. For example, there is a method in which the front plate glass and the back plate glass to be used are made into glasses having the same production history. In addition, thorough management of the material of the plate glass, measurement of the thermal expansion coefficient frequently, and selection of the front plate glass and the back plate glass with matching thermal expansion coefficients can be considered. Furthermore, in order to reduce the difference in thermal expansion coefficient between the front plate glass and the back plate glass, the manufacturing conditions of the plate glass (for example, when manufactured by the float method, precise temperature control and melting of the glass melt flowing into the tin bath) A thorough management method such as precise temperature control of tin, precise control of heater output and prevention of output fluctuations, and strict management of batch component fluctuations is also effective. In order to regulate the difference in thermal expansion coefficient between the front plate glass and the back plate glass to ^0.5 X 10 ^_7 / ° C or less, it is necessary to use the above methods in combination as appropriate.

[0013] When the front plate glass and the back plate glass to be used are cut out from the same base glass, the difference in thermal expansion coefficient between the front plate glass and the back plate glass can be reduced. However, when manufacturing a display panel by cutting out the front plate glass and the rear plate glass from the same mother glass, there are unreasonable restrictions on the combination of the front plate glass and the rear plate glass. Therefore, the productivity of the display panel is lowered. Therefore, in the manufacture of display panels, it is inevitable to combine plate glasses with different production dates, and the manufacturing process of the plate glass is strictly controlled to reduce the difference in thermal expansion coefficient between the front plate glass and the back plate glass. It becomes important. On the other hand, the difference in thermal expansion coefficient between the front plate glass and the rear plate glass is preferably ^0.01 X 10 ^_7 / ° C or more. If the difference in coefficient of thermal expansion between the front plate glass and the back plate glass is regulated to less than ο · 01 X 1CT ⁷ / ° C, the plate glass manufacturing cost may increase and the display panel manufacturing cost may increase.

The invention's effect

[0015] The display panel of the present invention has a thickness of less than 2.8 mm between the front plate glass and the rear plate glass, which is sealed with the display panel in which the front plate glass and the rear plate glass are hermetically sealed via the low melting point sealing glass. In order to control the difference in thermal expansion coefficient between the front plate glass and the back plate glass to 2.0 X 1 0 ^_7 / ° C or less, the front plate glass and the back plate glass are low melting point sealing glass in the display panel manufacturing process. When it is hermetically sealed, it can greatly contribute to achieving a large display, high definition, and light weight of the display panel without warping the glass sheet. In particular, according to the display panel of the present invention, it is possible to remarkably reduce the warpage of the plate glass caused by the difference in thermal expansion coefficient between the front plate glass and the back plate glass, and in addition, the display panel screen is distorted, curved, or blurred. Etc. can be remarkably reduced. In addition, an internal structure in which the inside of the cell is appropriately partitioned can be ensured, and as a result, high-definition image quality without turbidity (crosstalk) of the emission color can be realized. In the present invention, the “thermal expansion coefficient difference” means an average thermal expansion coefficient difference in a temperature range of 30 to 380 ° C. Further, in the display panel of the present invention, the front plate glass and the back plate glass are not intended to exclude an aspect in which the glass composition is different.

BEST MODE FOR CARRYING OUT THE INVENTION

[0016] As described above, the weight of the entire PDP can be greatly reduced by reducing the thickness of the power plate glass in which a plate glass having a thickness of 2.8 mm is mainly used for the PDP. However, if the plate thickness of the plate glass is reduced, the warpage of the plate glass increases due to the difference in thermal expansion coefficient between the front plate glass and the back plate glass, and the tendency is large when the plate thickness is less than 2.5 mm, and less than 2.0 mm. When it is larger than 1. When it is less than 5mm, it is even larger. If the thickness of the plate glass is halved, the warp of the display panel due to the difference in thermal expansion coefficient between the front plate glass and the back plate glass will be doubled. That is, as the plate thickness of the plate glass is reduced, the effect brought about by the display panel force S of the present invention can be enjoyed more accurately. Also, plate glass thickness If the front plate glass and the rear plate glass have a difference in thermal expansion coefficient of 2.8 mm or more, the display panel warps when the front plate glass and the rear plate glass are hermetically sealed with the low melting point sealing glass. The effect of the display panel of the present invention is poor.

[0017] In the display panel of the present invention, the thermal expansion coefficient difference of the back plate glass front plate glass is a 2.0X10- ⁷ / ° C or less, preferably 1. 0X10- ⁷ / ° C or less, more preferably 0. 7X10- ⁷ Z ° C, more preferably 0. 5X10- ⁷ Z ° C, and most preferably not more than 0.4X10- ⁷ / ° c. The higher the definition of the display panel, the greater the effect of display warpage on the display image. In particular, have you the high-definition PDP of 40 inches or more, desirable that the thermal expansion coefficient difference of the back plate glass front plate glass below 0. 5X10_ ⁷ / ° C instrument particularly, the thickness of the glass sheet 2. Omm If the temperature is less than the range, warping of the display is likely to occur. Therefore, it is significant to regulate the difference in thermal expansion coefficient between the front plate glass and the rear plate glass to ^{0.5X10 _7} Z ° C or less. The difference in thermal expansion coefficient between the front plate glass and the back plate glass is 2.0X10 ⁷ /. If it is larger than C, it is difficult to suppress warping of the display, and as a result, there is a greater risk of adversely affecting the display image.

[0018] Further, the thickness of the plate glass is t (mm), the thermal expansion coefficient of the front plate glass is _α (X 10 " ⁷ / ° Ο, and the thermal expansion coefficient of the rear plate glass is α (X 10

2 "V ° C) and the glass sheet size is less than 40 inches,

2.When 0≤t <2.8, -2. 0≤ (α-a) ≤2.0

1 2

1.When 5≤t <2.0, -1. 1≤ (α-a) ≤1.1

1 2

0. 5 <t <l.5, -0. 9≤ (α-a) ≤0.9.

1 2

If it restrict | limits to, since the curvature of a display panel can be prevented more correctly, it is preferable.

[0019] The thickness of the plate glass is t (mm), the coefficient of thermal expansion of the front plate glass is ^H (X 10 ^→ / ° C), and the coefficient of thermal expansion of the rear plate glass is ^H (X 10-so C). 40 inches or more in size 1

2

For 20 inches or less,

2. 0≤t <2. 8, -1. 0≤ (a-a) ≤1.0

1 2

1. 5≤t <2. 0, -0. 5≤ (a-a) ≤0.5

1 2

0. 5 <t <l. 5; -0. 4≤ (a-a) ≤0.4 If it restrict | limits to, since the curvature of a display panel can be prevented more correctly, it is preferable.

[0020] Furthermore, the thickness of the plate glass is t (mm), and the thermal expansion coefficient of the front plate glass is α (X 10_ ⁷

1

/ ° C), the coefficient of thermal expansion of the back plate glass is α (X 10—

2 Seo. C) and the size of the glass sheet ¾0 inches or more and 120 inches or less,

2.0≤t <2.8,-0. 5≤ (a-a) ≤0.5

1 2

1. 5 ≤ t <2. 0,-0. 25 ≤ (a-a) ≤ 0.25

1 2

0. 5 <t <l .5,-0. 2≤ (a-a) ≤0.2

1 2

If it restrict | limits to, since the curvature of a display panel can be prevented more correctly, it is more preferable.

[0021] The size of the glass sheet according to the display panel of the present invention is preferably 37 inches (eg, length of 500 mm x width of 900 mm) or more and 32 inches (eg, length 450 mm x width 800 mm), and 42 inches (eg, 550mm x 1000mm), 50 inches (eg 700mm x 1200mm), 58 inches (800mm x 1350mm), 65 inches (eg 850mm x 1500mm) and more preferable. As the plate glass size increases, the warpage of the display panel due to the difference in thermal expansion coefficient between the front plate glass and the back plate glass increases. That is, as the size of the plate glass increases, the effect brought about by the display panel of the present invention can be properly enjoyed. In addition, if the size of the plate glass is less than 32 inches, even if there is a difference in the thermal expansion coefficient between the front plate glass and the rear plate glass, when the front plate glass and the rear plate glass are hermetically sealed with the low melting point sealing glass, the display panel Therefore, the effect of the display panel of the present invention becomes poor.

The sealing thickness of the low-melting point sealing glass according to the display panel of the present invention is less than 500 μm, preferably less than 400 zm, more preferably less than 300 zm, more preferably less than 300 zm, more preferably less than 250 zm. Most preferred. If the sealing thickness of the low melting point sealing glass is reduced, the degree of adhesion between the front plate glass and the rear plate glass is increased, and the warpage of the display panel is increased. That is, as the sealing thickness of the low melting point sealing glass becomes smaller, the effect brought about by the display panel of the present invention can be enjoyed more accurately. In addition, when the sealing thickness of the low melting point sealing glass is 500 μm or more, the front and rear glass plates are hermetically sealed with the low melting point sealing glass even if there is a difference in thermal expansion coefficient between the front and rear glass plates. Display when wearing There is a tendency that the lay panel is less likely to warp, and the effect brought about by the display panel of the present invention becomes poor. In the present invention, “low melting point” refers to a case where the softening point measured by a differential thermal analysis (DTA) apparatus is 600 ° C. or lower.

[0023] The strain point of the plate glass according to the display panel of the present invention is preferably 570 ° C or more, more preferably 580 ° C or more, more preferably 590 ° C or more, and most preferably 600 ° C or more. If the glass strain point is less than 570 ° C, the glass sheet tends to crack or warp due to the thermal characteristics of the glass sheet during the heat treatment process when manufacturing the display panel. It becomes easy to cause deformation.

The plate glass according to the display panel of the present invention can use various glasses such as soda lime glass, borosilicate glass, aluminosilicate glass, barium strontium glass, and the like. ○ 50-70%, Α1 Ο 0-10%

2 2 3

, MgO 0 to: 10%, Ca 0 to 10%, SrO 0 to 15%, Ba 0 0 to 15%, ZrO 0 to

2

10%, B O 0-5%, Na 0 0-: 10%, K O 0-: 10%, and thermal expansion

2 3 2 2

It is preferable to use a glass having a number of 60 to 90 ^× 10 ^_7 / ° C. In addition, the following% display points out the mass% unless there is particular limitation.

[0025] SiO is a glass network former. Suitable content is 50-70%, especially

2

54-70%. When the amount of SiO increases, the meltability deteriorates, and when it decreases, the strain point of the glass

2

Decreases and thermal deformation and thermal shrinkage tend to increase.

[0026] Al 2 O is a component that increases the strain point of glass. Suitable content is 0 to: 10%, in particular 0 to 8

twenty three

%. As A10 increases, high-temperature viscosity tends to increase, making glass molding difficult

twenty three

There is power ^S.

[0027] MgO is a component that lowers the high-temperature viscosity of the glass to increase the moldability and meltability of the glass and increase the strain point of glass. The preferred content is 0 to: 10%, in particular 1 to 9%. When the amount of MgO increases, the devitrification temperature of the glass tends to increase.

[0028] Like MgO, CaO is a component that lowers the high-temperature viscosity of glass to improve the moldability and meltability of the glass and increase the strain point of the glass. The preferred content is from 0 to: 10%, in particular from 0 to 6%. When CaO increases, the devitrification temperature of the glass tends to increase.

[0029] SrO lowers the high temperature viscosity of the glass to improve the moldability and meltability of the glass. It is a component that raises the strain point of the process. The preferred content is from 0 to: 15%, in particular from 2 to: 13%. Sr_〇 is the density of the glass is increased more, also there tends force ^s devitrification temperature of the glass rises.

[0030] BaO, like SrO, is a component that lowers the high-temperature viscosity of the glass and increases the moldability and meltability of the glass. The preferred content is 0 to: 15%, in particular 0 to 8%. When BaO increases, the glass density increases and the devitrification temperature of the glass tends to increase. Since BaO is an environmentally hazardous substance, it is desirable to reduce it as much as possible without damaging its properties.

[0031] ZrO is a component that increases the strain point of glass. The preferred range is 0 to: 10%, especially 0 to 6%

2

It is. When ZrO increases, the density of the glass tends to increase.

2

[0032] B 2 O is a component that lowers the viscosity of the glass and improves the meltability and formability.

twenty three

It is preferable to limit the content to 5% or less, since the strain point of the glass is significantly reduced. If the content of B〇 exceeds 5%, it will be added to the plate glass in the thermal process when manufacturing PDP.

twenty three

Cracks and warpage are likely to occur, and thermal deformation and shrinkage are likely to occur in the glass sheet.

[0033] NaO is a component that controls the coefficient of thermal expansion of glass and increases the meltability of glass.

2

is there. The preferred content is 0 to: 10%, in particular 1 to 7%. When NaO increases, the distortion of the glass

2

There is a tendency for points to drop.

[0034] KO, like Na 2 O, controlled the coefficient of thermal expansion of glass and increased the meltability of glass.

twenty two

This component is The preferred content is 0 to 10%, in particular 2 to 10%. K O is a lot

2

Then, the strain point of the glass tends to decrease.

In addition to the above components, the plate glass used in the present invention can be applied with various components. For example, to prevent coloring by ultraviolet rays, up to 5% of Ti〇 and CeO

twenty two

In order to lower the liquidus temperature and improve the moldability, 3% each of Y 2 O, La 2 O, and Nb 0

2 3 2 3 2 5

In order to improve water resistance, ZnO is up to 5%, and in order to improve crack resistance, P O

2 5 can be added up to 4%. Furthermore, clarifiers such as As〇, Sb〇, S〇, SnO, CI etc.

2 3 2 3 3 2

Add up to 1% of total components, and add up to 1% of each colorant component such as FeO, CoO, NiO, CrO.

2 3 2 3

It is possible to add. [0036] thermal expansion coefficient of the glass sheet according to the display panel of the present invention, in the temperature range of 30 to 380 ° C, preferably it is 60~90 X 10- ⁷ / ° C instrument 65~85 X 10- ⁷ / ° C is even better. When the thermal expansion coefficient becomes larger than 90 X 10_ ⁷ / ° C, Oite the manufacturing process of the display panel, heat cracking of the glass sheet due to the thermal expansion coefficient of the glass tends to occur. When the thermal expansion coefficient of less than 60 X 10- ⁷ / ° C, due to inconsistent thermal expansion coefficient of the dielectric glass or low melting point sealing glass and plate glass, as a result, the plate glass in the manufacturing process of the display panel The problem of thermal cracking is likely to occur.

[0037] The plate glass according to the display panel of the present invention is charged with a glass raw material prepared to have a desired glass composition in a continuous melting furnace, and the glass raw material is heated and melted, defoamed, and then supplied to a molding apparatus. It can be produced by forming molten glass into a plate shape and slowly cooling it. As a method for forming the plate glass according to the display panel of the present invention, various forming methods such as a float method, a slot down draw method, an overflow down draw method, a redraw method and the like can be adopted, but the plate method is formed by the float method. It is preferable to do. The reason is that in the case of the float process, it is easy to obtain a large plate glass at a relatively low cost.

[0038] When a glass substrate is formed by the float process, the glass may be colored by a reducing atmosphere such as molten tin hydrogen or nitrogen. If a colored glass substrate is used as the front plate glass, it may cause problems such as deterioration of the image quality of the display panel. It can be used as the back plate glass.

[0039] The display panel of the present invention can have a structure corresponding to the type of display to be applied. For example, in the case of PDP, an dielectric layer is formed on the surface of the front plate glass and the back plate glass. The formed dielectric layer regulates the thermal expansion coefficient of the dielectric layer to the value described in Patent Document 3, thereby suppressing the warpage of the display panel due to the difference in thermal expansion coefficient between the plate glass and the dielectric layer. Can be suppressed. In addition, when using lead-free dielectric glass for the dielectric layer, the residual stress remaining on the plate glass should be as small as possible in order to suppress warpage and cracking of the plate glass due to the difference in thermal expansion coefficient between the plate glass and the dielectric layer. However, if the residual stress remaining on the glass sheet is regulated within the range of _800 to 1500 (psi) (preferably 1 to 1300 (psi), more preferably 0 to 1300 (psi)), the above problem will be solved. It becomes difficult to occur. In addition, “residual stress remaining in the plate glass” means that in the plate glass after firing, It means the residual stress existing in the plate glass observed when the interface with the dielectric layer is observed with a strain gauge. If the residual stress is a compressive stress, it is indicated by a “negative” value. If it is a bow stress, it is indicated by a “positive” value.

[0040] The low melting point sealing glass used in the display panel of the present invention includes a PbO-B 2 O-based glass.

2 3 Glass, BiO1 BO glass, SnO-PO glass, VO1 PO glass, etc.

2 3 2 3 2 5 2 5 2 5

Various glasses can be used. In particular, BiO1 BO glass, SnO-PO gas

2 3 2 3 2 5 Las, V O -PO glass can be made into a glass composition that does not substantially contain PbO.

2 5 2 5

Therefore, it can meet recent environmental demands. Here, “substantially does not contain PbO” refers to the case where the content of PbO in the glass composition is lOOOppm or less.

[0041] Bi_〇 _B O based glass, a glass composition, in mol ^_0/0 Display, Bi_〇 30 to 50%, B

2 3 2 3 2 3

O 20 to 35%, ZnO:! To 25% (preferably 10 to 25%), BaO 0 to 15% (preferably

twenty three

:! ~ 15%), BaO + SrO + MgO + CaO 0 ~ 20% (preferably 3 ~: 15%). If the glass composition range is regulated as described above, a glass having a low melting point and good thermal stability can be obtained.

[0042] SnO-P O based glass, a glass composition, in mol ^_0/0 Display, Sn_〇 40 to 70%, P

2 5 2

O 20 to 40%, SiO 0 to 10%, ZnO 0 to 25% (preferably:! To 20%), B 0

5 2 2 3

It preferably contains ˜25% (preferably 1-20%). If the glass fiber formation range is regulated as described above, a glass having a low melting point and good water resistance and thermal stability can be obtained.

[0043] V_〇 one P_〇 based glass, as a glass composition, in mol ^_0/0 Display, VO 10 to 60%, P

2 5 2 5 2 5 2

O 5-40%, Bi 0 0-30% (preferably 1-10%), 2110 0-40%, Ding 60 0

5 2 3 2

It is preferable to contain -40%, RO (R is one or more selected from Mg, Ca, Ba, Sr) 0-35% (preferably 3-25%). If the glass composition range is regulated as described above, a glass having a low melting point and good water resistance and thermal stability can be obtained.

[0044] The low-melting point sealing glass has a thermal expansion coefficient matching with that of the plate glass. A fireproof filler is appropriately added for the purpose of improving the mechanical strength of the low-melting point sealing glass (for example, with respect to 100 parts by weight of the glass). Use 5 to 80 parts by weight of refractory filler). The thermal expansion coefficient of the low melting point sealing glass is adjusted so that a slight stress of tension is applied to the plate glass. Also fire resistant filler As one example, cordierite, willemite and tin oxide are made of Bi〇 BO-based glass, S

2 3 2 3

It is suitable for compatibility with nO—P 2 O glass and V 2 O 3 —P 2 O glass.

2 5 2 5 2 5

[0045] The softening point of the low melting point sealing glass is preferably 450 ° C or lower. When the softening point of the low melting point sealing glass is higher than 450 ° C, the sealing temperature must be higher than 530 ° C. Therefore, when air-sealing the front and back plate glasses with the low melting point sealing glass, There is a risk of thermal deformation and thermal contraction due to the thermal properties (strain point, etc.) of the plate glass.

[0046] The display panel of the present invention is preferably applied to a PDP. This is because PDP has a strong need to reduce the thickness of plate glass and increase the size of plate glass, which demands large screen size, high definition and light weight. In addition, PDP performs hermetic sealing between the front and rear glass plates in a thermal process of approximately 450 to 520 ° C, and the plate glass caused by the difference in thermal expansion coefficient between the front and rear glass sheets in the sealing process. This is because there is a high risk of warping.

[0047] The display panel of the present invention is preferably applied to a field emission display (hereinafter referred to as FED). According to the present invention, the warp of the plate glass can be reduced, the distance between the front plate glass and the rear plate glass can be made uniform, and the acceleration voltage applied between the front plate glass and the rear plate glass inside the FED apparatus. It is unlikely that the brightness of the FED will be adversely affected by variations in the speed of electrons or changes in the velocity of electrons that impact the phosphor. In addition, FED, like PDP, has a strong need to reduce the plate thickness and increase the size of the plate glass, which demands a larger screen, higher definition, and lighter weight. Needless to say, the FED referred to in the present invention includes all types of FED having various electron-emitting devices.

[0048] The structure of the present invention is a structure in which a front plate glass and a rear plate glass are hermetically sealed via a low-melting glass, and the thickness of the front plate glass and the rear plate glass is less than 2.8 mm, and the front plate glass And the difference in thermal expansion coefficient between the back plate glass and 2.0 × 10_ ⁷ Z ° C or less. Since the structure of the present invention can have the same structure and effects as the display panel of the present invention described above, the description thereof is omitted here for convenience. Needless to say, the structure of the present invention can have the same characteristics as those of the display panel of the present invention. [0049] The flat glass set for producing a display panel of the present invention is a flat glass set for producing a display panel having a front plate glass and a back plate glass, and has a coefficient of thermal expansion of the front plate glass and a coefficient of thermal expansion of the back plate glass. -2. 0 X 10_ ⁷

1 2

/ ° C≤. (A - a ) ≤2 characterized in meeting a 0 X 10_ ⁷ / ° C relationship. Main departure

1 2

If a display panel is produced using the bright plate glass set for producing a display panel, the obtained display panel can have the same effects as the display panel of the present invention, in addition to the same characteristics. The description is omitted here for the sake of convenience.

[0050] The front plate glass of the present invention is a front plate glass for producing a display panel having a front plate glass and a back plate glass, wherein the thermal expansion coefficient of the front plate glass is used and the thermal expansion coefficient of the rear plate glass is used. When ^_2.0 x ^10_7 /. C≤ (one one) ≤ 2. OX

2 1 2

Characterized by satisfying the relationship of io ^_7 Z ° c. If a display panel is produced using the front plate glass of the present invention, the resulting display panel can have the same functions and effects as the display panel of the present invention. Therefore, the description thereof is omitted here for convenience.

[0051] The back plate glass of the present invention is a back plate glass for producing a display panel having a front plate glass and a back plate glass. The thermal expansion coefficient of the front plate glass is α, and the thermal expansion coefficient of the back plate glass is α. When, 2.0 X 10 ^{_7 /°C≤(a~a)≤2.OX}

2 1 2

Characterized by satisfying the relationship of 1 o ^_7 / ° c. If the back plate glass of the present invention is used to produce a display panel, the obtained display panel can have the same functions and effects as the display panel of the present invention. Therefore, the explanation is omitted here for the sake of convenience.

Example

The display panel according to the present invention will be described in detail based on examples. Tables 1 to 3 show examples of the present invention, and Table 4 shows comparative examples of the present invention.

[0053] First, front plate glasses and back plate glasses having thermal expansion coefficients, strain points, and plate thicknesses as shown in Tables 1 to 4 were prepared. The front plate glass and the back plate glass shown in Tables 1 to 4 have the same electrode and dielectric layer formed. A lath having no cracks or warpage was used. In addition, the thermal expansion coefficients of the low melting point sealing glass and the dielectric layer are set to values that do not cause a mismatch with the thermal expansion coefficient of the plate glass. As a result, the low melting point sealing glass' dielectric layer The thermal deformation and thermal shrinkage caused by the mismatch between the thermal expansion coefficients of the glass and the plate glass were set to negligible values. For other parts, PDPs were prepared using conventional PDP manufacturing parts and conventional PDP manufacturing methods.

[0054] The plate glass used in Tables 1, 2, and 4 was a 42 inch diagonal size with length: width = 16: 9. The plate glass used in Table 3 was a 50 inch diagonal size with length: width = 16: 9.

[0055] The thermal expansion coefficient of the plate glass was calculated by measuring the average thermal expansion coefficient in a temperature range of 30 to 380 ° C using a plate glass described in the Examples as a sample and a dilatometer.

[0056] The strain point of the sheet glass was measured by a method in accordance with ASTM C336-71. As the temperature of the strain point is higher, it becomes possible to suppress thermal deformation and thermal contraction of the plate glass due to the thermal process in manufacturing the display. In the examples of the present invention, the strain point of the front plate glass and the back plate glass is considerably higher than the sealing temperature of the low melting glass, so that the glass deformation due to the thermal characteristics of the glass is negligibly small. is there.

[0057] Bi O — B〇 low melting point lead-free seal for hermetic sealing of front and rear plate glass

2 3 2 3

Uses glass that has a thermal expansion coefficient of 69 X 10 ^_7 / ° C at 30 to 250 ° C, and a soft spot measured by a macro-type differential thermal analyzer (DTA) of 425 ° C. did. In addition, the hermetic sealing between the front plate glass and the rear plate glass was performed by applying the low melting point sealing glass paste on the outer periphery of the rear plate glass with a dispenser, and then baking it in a belt-type baking furnace. The sealing conditions were set at a temperature rise / fall of 2 ° C / min and held at the sealing temperature in the table for 30 minutes.

[0058] The substrate damage of the display panel was visually observed. The plate glass with no cracks was marked with “◯”, and the plate glass with cracks was marked with “X”.

[0059] The amount of warpage of the display panel was calculated by irradiating a plate glass with a laser beam in parallel along the plate width direction and measuring the amount of change in shading of the laser beam due to the amount of warpage of the plate glass. Display panel warpage width for each side of the front glass And the value having the largest warp width was defined as the “warp amount”. A display with a warp of less than 3.5 mm means that the image quality is not reduced due to the effects of screen distortion, curvature, blurring, and so on.

[table 1]

[Table 2]

Example

6 7 8 9 1 0 Thermal expansion coefficient

84. 5 83. 4 83. 0 70. 0 82. 6

^{(X 10 - 7 / ° c} )

Face plate

Glass

Strain point (° c) 585 585 585 600 600 Thickness (mm) 1. 8 1. 8 1. 8 1. 9 1. 0 1 'Panel thermal expansion coefficient

84. 0 83. 0 83. 3 70. 1 82. 9 (X 10- ⁷ /)

Back plate

Glass strain point (in) 585 585 585 600 600 Thickness (mm) 1. 8 1. 8 1. 8 1. 9 1. 0 Difference in thermal expansion coefficient Δ a

0. 5 0. 4 0. 3 0. 1 0. 3 (X10— ⁷ / ° C)

Sealing temperature (t) 450 450 450 500 500 Board breakage O O O o 〇 Warpage (mm) 1. 3 1. 0 0. 8 0. 3 1. 5

]

Example

1 1 1 2 13 14 15 Thermal expansion coefficient

84.5 83.4 83.0 70.0 82.6 a front plate glass (X 10- ⁷ Ζ X)

Las

Strain point (° c) 585 585 575 600 600 Display fe thickness (mm 1. 8 1. 8 2. 0 1. 8 1. 0 Panel thermal expansion coefficient

84. 0 83. 0 83. 3 70. 1 S 2. 9 Back panel (X 10)

Lath strain point () 585 585 575 600 600 te J ¥ (m m 1. 8 1. 8 2. 0 1. 8 1. 0 Difference in thermal expansion coefficient

0. 5 0. 4 0. 3 0. 1 0. 3 (X10—Zo. C)

Sealing temperature (° C) 450 450 450 500 500 Board breakage ○ ○ ○ ○ ○ Warpage (mm) 1. 8 1. 4 1. 0 0. 4 2. 2

Comparison example

1 Thermal expansion coefficient

(°)

Face plate

Glass

Strain point

display

No

Thermal expansion coefficient

(x z)

Back plate

Glass strain point (

Enjoyment

Thermal expansion coefficient difference Δ 1

(x io- ⁷ / ° C)

Sealing temperature () Substrate breakage ○ ○ ○ ○ Warpage (―

[0064] Table: Examples of! ~ 3 No .: The display panel shown in! ~ 15 has a difference in thermal expansion coefficient between the front plate glass and the rear plate glass of 2.0 X 10 ^_7 / ° C or less. Therefore, the substrate was not damaged, and the amount of warpage of the display panel was 0.4 to 3.4 mm. As a result, the display panels shown in Tables:! To 3 of Example No .:! To 15 are judged to have little effect of screen distortion, curvature, blurring, etc., and the image sharpness is not impaired. The

[0065] Display panel shown in Comparative Example No. 1 of Table 4, the thermal expansion coefficient difference of the back plate glass front plate glass for greater than ^{6. 0 X 10- 7 / ° C} , the substrate was damaged. Display panel shown in Comparative Examples No. 2 to 4 of Table 4, the thermal expansion coefficient difference of the back plate glass front plate glass 2.:! ~ 4 as large as 0 X 10- ⁷ Z ° C, the display panel The amount of warpage was a large value of 3.9 to 6.7 mm. As a result, the display panels shown in Comparative Examples Nos. 2 to 4 in Table 4 are judged to have lost the sharpness of the image, which is greatly affected by distortion, curvature, blurring, etc. of the screen. Comparative example No. 5 in Table 4 has a large plate glass thickness of 3.5 mm, but the difference in thermal expansion coefficient between the front plate glass and the back plate glass is as large as 3.0 X 10 ^_7 Z ° C. The amount of warpage was 3.9 mm. [0066] For reference, Table 5 shows glass composition examples of plate glass applicable to the display panel of the present invention. For example, when the glass composition of the front plate glass is Glass A, the glass composition of the back plate glass is Glass B, and a display panel is produced in the same manner as Example No. 1 in Table 1, the amount of warpage of the display panel obtained is It can be seen that the value is the same as that of the display panel of Example No. 1 of 1.

[0067] [Table 5]

Industrial applicability

[0068] The display panel of the present invention has a thickness of less than 2.8 mm between the front plate glass and the rear plate glass, which is sealed with the display panel in which the front plate glass and the rear plate glass are hermetically sealed via a low melting point sealing glass. In order to control the difference in thermal expansion coefficient between the front plate glass and the back plate glass to 2.0 X 1 0 ^_7 / ° C or less, the front plate glass and the back plate glass are low melting point sealing glass in the display panel manufacturing process. When it is hermetically sealed, it can greatly contribute to achieving a large display, high definition, and light weight of the display panel without warping the glass sheet. In particular, according to the display panel of the present invention, it is possible to remarkably reduce the warpage of the plate glass caused by the difference in thermal expansion coefficient between the front plate glass and the back plate glass, and in addition, the display panel screen is distorted, curved, or blurred. Etc. can be remarkably reduced. In addition, it is possible to secure an internal structure in which the inside of the cell is appropriately partitioned, and as a result, it is possible to realize high-definition image quality with no turbidity of emission color (crosstalk).

[0069] Therefore, the display panel of the present invention is suitable not only for PDP but also for other displays. The display panel of the present invention is, for example, FED, plasma display. It is also suitable for dressed liquid crystal panels (PALC).

Claims

The scope of the claims

[1] In a display panel in which the front plate glass and the rear plate glass are hermetically sealed via a low melting point sealing glass, the thickness of the front plate glass and the rear plate glass is less than 2.8 mm, and the front plate glass and the rear plate glass are A display panel characterized by a difference in thermal expansion coefficient of 2. OX 10_ ⁷ Z ° C or less.

[2] The display panel according to claim 1, wherein a difference in thermal expansion coefficient between the front plate glass and the back plate glass is 1.0 X 10 ^_7 Z ° C or less.

[3] The display panel according to claim 1 or 2, wherein a difference in thermal expansion coefficient between the front plate glass and the rear plate glass is ^0.5 X 10 ^_7 / ° C or less.

[4] The thickness of the front plate glass and the back plate glass is less than 2. Omm.

The display panel according to any one of 1 to 3.

[5] The display panel according to any one of claims 1 to 4, wherein the size of the front plate glass and the rear plate glass is 32 inches or more.

[6] The display panel according to any one of [1] to [5], wherein the sealing thickness of the low melting point sealing glass is less than 500 _βm .

[7] The low melting point sealing glass is BiO_B O based low melting point sealing glass, and the soft spot is 450

2 3 2 3

The display panel according to any one of claims 1 to 6, wherein the display panel is at or below ° C.

[8] The strain point of the front plate glass and the rear plate glass is 570 ° C or higher.

The display panel according to any one of to 7.

[9] The front plate glass and the back plate glass are expressed in mass% as the glass composition.

SiO 50 to 70%, Α1 Ο 0 to: 10%, Mg 0 0 to 10%, CaO 0 to 10%, Sr 0

2 2 3

~ 15%, BaO 0 ~: 15%, ZrO 0 ~: 10%, B O 0 ~ 5%, Na〇 0 ~ 10%, K

2 2 3 2 2

O 0-: 10% is contained, and the thermal expansion coefficient in the temperature range of 30 to 380 ° C is 60 to 90 X 10 ^_7 / ° C. Display panel.

10. The display panel according to any one of claims 1 to 9, wherein the display panel is a plasma display panel.

11. The display panel according to any one of claims 1 to 9, wherein the display panel is a field emission display panel.

[12] In a structure in which the front plate glass and the rear plate glass are hermetically sealed via a low melting point sealing glass, the thickness of the front plate glass and the rear plate glass is less than 2.8 mm, and the front plate glass and the rear plate glass Difference in thermal expansion coefficient of 2. OX 10_ ⁷ Z ° C or less.

[13] A plate glass set for producing a display panel having a front plate glass and a back plate glass, which has a coefficient of thermal expansion of the front plate glass and a coefficient of thermal expansion of the back plate glass.

When a 1 2 One 2. 0 X 10- ⁷ /. C≤ (Hi-a) ≤ 2. OX 10 ⁷ /. Satisfy the relationship of C

1 2

A flat glass set for manufacturing a display panel.

[14] A front plate glass for producing a display panel having a front plate glass and a rear plate glass, which has a coefficient of thermal expansion of the front plate glass and a coefficient of thermal expansion of the back plate glass.

When 1 2 is ^{satisfied, the relationship of} 2.0 X 10 ^_7 / ° C≤ (α-a) ≤ 2 · 0 X 10 ^_7 / ° C ^{must be satisfied} .

1 2

Front plate glass characterized by

[15] A back plate glass for producing a display panel having a front plate glass and a back plate glass, wherein the thermal expansion coefficient of the front plate glass is α and the thermal expansion coefficient of the back plate glass is α.

1 2

A back plate glass characterized by.