KR100658732B1 - Glass composition for vacuum exhaust/sealing of plasma display panel - Google Patents

Abstract

Provided is a glass composition for vacuum exhaust/sealing of a plasma display panel, which generates neither gas nor bubbles during vacuum-high temperature decomposition and is superior in adhesion and a thermal characteristic matching property. The glass composition for vacuum exhaust/sealing of a plasma display panel comprises Bi2O3 60-85wt%, B2O3 5-30wt%, SiO2 0.5-10wt%, ZnO 5-20wt%, TiO2 1-20wt%, BaO 0.1-3wt%, Al2O3 1-5wt%, and ZrO2 1-20wt%. The glass composition further includes at least one selected from the group consisting of MgO, CaO, SrO, CeO2, La2O3, and SiO2. The glass composition has an average thermal expansion coefficient of 60Î10^(-7) to 90Î10^(-7) at room temperature to 300 deg.C.

Description

Glass composition for vacuum sealing of plasma display panel {GLASS COMPOSITION FOR VACUUM EXHAUST / SEALING OF PLASMA DISPLAY PANEL}

Figure 1 is a photograph showing the results of the vacuum sealing step of the plasma display panel using the glass composition for vacuum sealing prepared according to Comparative Example 1.

[Industrial use]

The present invention relates to a glass composition for vacuum encapsulation of a plasma display panel, and more particularly, to a glass composition for vacuum encapsulation of a plasma display panel excellent in adhesion without generating gas and bubbles rapidly during vacuum encapsulation. .

[Prior art]

In general, a plasma display panel (PDP) is a display device that realizes an image by using visible light generated by vacuum ultraviolet (VUV) radiation emitted from a plasma formed by gas discharge to excite a phosphor layer. Such a plasma display panel can be configured as a high resolution large screen, and thus has been in the spotlight as a next generation thin display device.

The general structure of the plasma display panel is a three-electrode surface discharge type structure. The three-electrode surface discharge structure includes a front substrate on which a display electrode composed of two electrodes is formed, and a back substrate on which an address electrode is formed at a predetermined distance from the substrate, wherein the display electrode is covered with a dielectric layer. . The space between the front substrate and the rear substrate is partitioned into a plurality of discharge cells by partition walls, discharge gas is injected into the discharge cells, and a phosphor layer is formed on the rear substrate side.

The process of manufacturing such a plasma display panel includes a front step of forming an electrode, a phosphor, and the like on a pair of front and back plates processed to a desired screen size, and the front and back surfaces manufactured by the previous step. After the sealing of the plate and injecting the gas in a vacuumed state, it consists of a module process of mounting a circuit on the panel surface of the plywood form.

In the post-process of the plasma display panel, the encapsulation exhaust process is one of very important processes for determining the characteristics of the finished plasma display panel, and is a process for removing the upper and lower plates and removing impurities therein. The sealing exhaust process heats the upper and lower plates to melt and seal the sealing frit while maintaining the assembling precision between the upper and lower plates. The impurity gas existing in the discharge space inside the panel is heated for a long time to make a clean space. After that, the discharge gas is filled in the panel and the exhaust pipe is tip-off to complete the panel.

However, since the sealed exhaust method exhausts the interior after sealing, the movement of gas through the narrow space partitioned by the partition wall is greatly restricted. That is, due to the very low exhaust conductivity it takes a long time to exhaust the impurity gas and also has a problem that the final delivery vacuum is also not excellent. In this process, if impurity gas is not completely removed and is present inside the panel, problems such as an increase in the discharge voltage of the plasma display panel and a decrease in discharge stability and ultimately a decrease in the lifetime of the plasma display panel Occurs.

In order to solve this problem, the vacuum sealed exhaust which heats and evacuates in a vacuum atmosphere with a very high conductivity before the upper and lower plates are sealed to create a high vacuum state in a relatively short time and then performs sealing to secure a very clean discharge space. Development of methods is urgently needed.

However, when the conventional atmospheric frit is applied to vacuum sealing, the volatilization temperature of the frit component is lowered at the sealing temperature due to the vacuum atmosphere, so that bubbles are generated in the frit during rapid gas generation and defoaming and eventually secure the adhesion required for sealing the upper and lower plates. There is a problem that can not be done.

SUMMARY OF THE INVENTION An object of the present invention is to provide a glass sealing composition for vacuum sealing of a plasma display panel having high adhesion strength and excellent thermal property matching by solving a problem of vacuum sealing process, that is, gas generation in vacuum and high temperature, and bubble generation. will be.

In order to achieve the above object, the present invention is Bi ₂ O ₃ 60 to 85% by weight, B ₂ O ₃ 5 to 30% by weight, SiO ₂ 0.5 to 10% by weight, ZnO 5 to 20% by weight, TiO ₂ 1 to 20 Provided is a glass composition for vacuum encapsulation of a plasma display panel comprising a weight%, BaO 0.1 to 3% by weight, Al ₂ O ₃ 1 to 5% by weight and ZrO ₂ 1 to 20% by weight.

Hereinafter, the present invention will be described in more detail.

The present invention relates to a glass composition capable of imparting excellent adhesion since there is no abrupt gas generation and bubble generation during the vacuum encapsulation process during the process of manufacturing the plasma display panel.

Glass composition of the present invention is 60 to 85% by weight Bi ₂ O ₃ , 5 to 30% by weight B ₂ O ₃ , 0.5 to 10% by weight SiO ₂ , 5 to 20% by weight ZnO, 1 to 20% by weight TiO ₂ , BaO 0.1 to 3 weight percent, 1 to 5 weight percent Al ₂ O ₃ and 1 to 20 weight percent ZrO ₂ . That is, the glass composition of this invention does not contain the low melting point PbO type glass powder.

Among the components constituting the glass composition of the present invention, Bi ₂ O ₃ is a main component of the glass composition, and its content is preferably 60 to 85% by weight. If the content of Bi ₂ O ₃ is less than 60% by weight, the softening point is increased and the fluidity is lowered. If the content of Bi ₂ O ₃ is higher than 85% by weight, the softening point is too low. This lowers and is not preferable.

In addition, B ₂ O ₃ is used to control the softening point, the content is preferably 5 to 30% by weight, more preferably 10 to 20% by weight. If the content of B ₂ O ₃ is less than 5% by weight, the softening point is increased, which is not preferable.

SiO ₂ is used to control the softening point and fluidity, and its content is preferably 0.5 to 10% by weight. When the content of SiO ₂ is less than 0.5% by weight, the effect of use is insignificant, and when it exceeds 10% by weight, the softening point is increased and the fluidity is poor, which is not preferable.

ZnO is used to control the softening point and fluidity, the content of which is preferably 5 to 20% by weight. If the content of ZnO is less than 5% by weight, there is a problem in that the softening point is increased and the fluidity is worsened.

The content of TiO ₂ is preferably 1 to 20% by weight. If the content of TiO ₂ is less than 1% by weight, there is a problem in that the effect of use is insignificant.

In addition, BaO plays a role of improving the adhesion property with the glass substrate, the content is preferably 0.1 to 3% by weight. If the content of BaO is less than 0.1% by weight, the effect of use is insignificant, and if it exceeds 3% by weight, there is a problem of increasing the coefficient of thermal expansion.

In addition, the content of Al ₂ O ₃ is preferably 1 to 5% by weight. If the content of Al ₂ O ₃ is less than 1% by weight, there is a problem in that the effect of use is insignificant.

In addition, the content of ZrO ₂ is preferably 1 to 20% by weight, more preferably 5 to 15% by weight, most preferably 10 to 15% by weight. If the content of ZrO ₂ is less than 1% by weight, there is a problem that the effect of use is insignificant.

In addition, although the alkali metal oxide may be inevitably included in the glass composition of the present invention due to impurities of the constituents, the content thereof is eluted with alkali metal during discharge and life of the display of 0.1 wt% or less, which adversely affects gas, phosphors, and the like. It is a very small range.

The glass composition of the present invention may also further contain one or more components selected from the group consisting of MgO, CaO, SrO, CeO ₂ , La ₂ O ₃ and SiO ₂ . If such a component is further included, physical properties such as durability, coefficient of thermal expansion or fluidity may be improved.

The glass composition of the present invention may further include a low expansion ceramic filler. These low expansion ceramic fillers include zircon, alumina, murayto, silica, titanate, cordierite, β-eucryptite, β-spodumene, β-quartz solid solution and mixtures thereof It includes. The content of the low-expansion ceramic filler may be added in the range of 2 to 50 parts by weight based on 100 parts by weight of the glass composition of the present invention in consideration of fluidity, strength, and coefficient of thermal expansion during sealing.

As for the average coefficient of thermal expansion from room temperature to 300 degreeC of the glass composition of this invention, 60 * 10 <^-7> -90 * 10 <^-7> / degreeC is preferable. If the average coefficient of thermal expansion of the glass composition is out of the above range, thermal stress due to the difference in expansion rate is largely present in the area where the glass and the frit are sealed during the high temperature heat treatment, so that a crack may occur during the process or a small impact afterwards. It can be undesirable.

Moreover, it is preferable that the glass composition of this invention has a transition temperature of 400 degrees C or less, Preferably it can carry out a sealing process at 500 degrees C or less. The material formed in the panel when the sealing process is carried out at a temperature higher than 500 ° C. That is, cracks may occur in MgO formed on the upper plate, and in the case of the lower plate, the phosphor may deteriorate at a high temperature, which is not preferable.

Hereinafter, preferred examples and comparative examples of the present invention are described. However, the following examples are only one preferred embodiment of the present invention and the present invention is not limited to the following examples.

(Example 1)

76 wt% Bi ₂ O ₃ , 8 wt% B ₂ O ₃ , 0.5 wt% SiO ₂ , 10 wt% ZnO, 1 wt% TiO ₂ , 2.0 wt% BaO, 1.5 wt% Al ₂ O ₃ and 1 wt% ZrO ₂ % Was mixed to prepare a glass composition for vacuum sealing.

The average thermal expansion coefficient of the prepared glass sealing composition was measured at 300 ° C., and the result was 81 × 10 ⁻⁷ / ° C. Moreover, it was 365 degreeC when the glass transition temperature was measured.

(Example 2)

It carried out similarly to Example 1 except that 10 weight part of cordierite low expansion ceramic fillers were further added with respect to 100 weight part of the said glass composition mixtures for vacuum sealing.

(Comparative Example 1)

78 weight% PbO, 9 weight% B ₂ O ₃ , 6 weight% SiO ₂ , 7 weight% ZnO and 3 weight% BaO, and 36 weight parts of titanate low expansion ceramic filler was added to 100 weight parts of the mixture. And the glass composition for vacuum sealing was manufactured.

The average thermal expansion coefficient of the prepared glass sealing composition was measured at 300 ° C., and the result was 72 × 10 ⁻⁷ / ° C.

After the vacuum sealing process of the plasma display panel was performed using the glass composition for vacuum sealing manufactured by the comparative example 1, the optical microscope photograph is shown in FIG. As shown in FIG. 1, it can be seen that gas and bubbles are seriously generated when the glass composition including PbO is used.

In addition, as a result of performing the vacuum sealing process of the plasma display panel using the vacuum sealing glass composition prepared according to Example 1, there was no gas generation and bubble generation.

As described above, the glass composition for vacuum encapsulation of the plasma display panel of the present invention is free of gas generation and bubbles during vacuum high temperature deposition, and has excellent adhesion and excellent thermal property matching.

Claims (6)

60 to 85 weight percent Bi ₂ O ₃ ; B ₂ O ₃ 5-30 weight percent; SiO ₂ 0.5-10 wt%; 5 to 20 weight percent ZnO; TiO ₂ 1-20 wt%; BaO 0.1 to 3 weight percent; Al ₂ O ₃ 1-5 weight percent; And ZrO ₂ 1-20 wt% Glass composition for vacuum sealing of the plasma display panel comprising a. According to claim 1, The glass composition further comprises at least one component selected from the group consisting of MgO, CaO, SrO, CeO ₂ , La ₂ O ₃ and SiO ₂ Glass composition for vacuum sealing of a plasma display panel. According to claim 1, The glass composition is a glass composition for vacuum sealing of the plasma display panel further comprises a low-expansion ceramic filler. The method of claim 3, wherein The low-expansion ceramic filler is plasma selected from the group consisting of zircon, alumina, murayto, silica, titanate, cordierite, β-eucryptite, β-spodumene, β-quartz solid solution and mixtures thereof Glass composition for vacuum sealing of a display panel. According to claim 1, The glass composition for vacuum sealing of the plasma display panel whose average coefficent of thermal expansion from room temperature to 300 degreeC of the said glass composition is 60 * 10 <^-7> -90 * 10 <^-7> / degreeC. According to claim 1, The glass composition is a glass composition for vacuum sealing of the plasma display panel having a transition temperature of 400 ℃ or less.

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