JP2008037710A - Glass composition and display panel using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a glass composition suitable for a display panel which has a low dielectric constant, which is excellent in the thermal decomposition property of a resin when mixed with the resin to be a paste and where yellowing is hardly caused when used for the coating material of electrodes such as silver and the like. <P>SOLUTION: The glass composition having a low softening point is characterized by containing at least B<SB>2</SB>O<SB>3</SB>, R<SB>2</SB>O (wherein, R is one or more kinds from among Li, Na and K) and V<SB>2</SB>O<SB>5</SB>whose content is 0.02 wt.% or more and 2 wt.% or less and by practically not containing lead. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a glass composition suitable for electrode coating and a display panel using the same, particularly a plasma display panel.

  In display devices and integrated circuits such as plasma display panels (hereinafter abbreviated as PDP), field emission displays, liquid crystal display devices, fluorescent display devices, ceramic laminated devices, and hybrid integrated circuits, electrodes made of Ag, Cu, etc. are provided on the surface thereof. And a substrate having wiring is used. In order to protect these electrodes and wirings, they may be covered with an insulating glass material. Here, a PDP which is a representative display device will be described as an example.

  Generally, a PDP has a structure in which a pair of electrodes regularly arranged on two opposing glass substrates are provided, and a gas mainly composed of an inert gas such as Ne or Xe is enclosed between the electrodes. A voltage is applied to the electrodes to generate a discharge in minute cells around the electrodes, thereby causing each cell to emit light and display. These electrodes are covered and protected with an insulating glass material called a dielectric layer.

  For example, a transparent electrode is formed on a glass substrate that serves as a front plate of an AC type PDP, and a metal electrode such as Ag, Cu, or Al having a lower resistivity is further formed thereon. A dielectric layer is formed to cover the composite electrode, and a protective layer (MgO layer) is further formed thereon.

  For the dielectric layer formed so as to cover the electrodes, glass having a low softening point is usually used. The dielectric layer is formed by applying a paste containing glass powder so as to cover the electrodes by a screen printing method, a die coating method, or the like, and then baking the paste.

Properties required for the glass composition forming the dielectric layer include:
(1) Since it is formed on the electrode, it is insulative.
(2) In a large-area panel, in order to prevent warping of the glass substrate, peeling of the dielectric layer and cracking, the thermal expansion coefficient of the glass composition is a value that is not much different from that of the substrate material (in practice, a slightly smaller value). Value is desirable).
(3) If it is for front plates, it is an amorphous glass with high visible light transmittance in order to efficiently use light generated from the phosphor as display light.
(4) The softening point is low so as to match the heat resistance of the substrate glass.
Etc.

As a glass substrate used for PDP, there are soda lime glass which is a window glass which is produced by a float process and is generally easily available, and high strain point glass developed for PDP. Heat resistance up to 75 × 10 ^{−7 to} 85 × 10 ⁻⁷ / ° C.

For this reason, as for the above-mentioned (2), the thermal expansion coefficient is desirably about 70 × 10 ⁻⁷ to 80 × 10 ⁻⁷ / ° C. Regarding (4), since the baking of the glass paste needs to be performed at 600 ° C. or lower, which is the strain point of the glass substrate, the softening point is at least so that the glass paste is sufficiently softened even when baking at a temperature of 600 ° C. or lower. It needs to be 595 ° C. or lower, more desirably about 590 ° C. or lower.

At present, PbO—SiO ₂ glass mainly composed of PbO is mainly used as a glass material that satisfies the above demands.

However, in consideration of recent environmental problems, a dielectric layer that does not contain Pb is required. Further, the dielectric constant of the glass material is required to be lowered from the current level in order to reduce the power consumption of the PDP. As a glass not containing Pb, a Bi ₂ O ₃ —B ₂ O ₃ —ZnO—SiO ₂ glass material containing zinc borate as a main component and having a low softening point by containing Bi instead of Pb (for example, patents) Literature 1) and the like have been developed, but these Bi-based materials also have a problem that the relative dielectric constant is as high as about 9 to 13 like the Pb-based materials. At present, a material having a relative dielectric constant of 7 or less, more preferably 6 or less, is required because it has a lower dielectric constant than these materials.

Therefore, in order to achieve both a low dielectric constant and a low softening point, materials that have achieved a relative dielectric constant of about 7 using a borate glass containing an alkali metal instead of Pb have also been proposed (for example, Patent Documents 2 to 4). .
JP 2001-139345 A JP-A-9-278482 JP 2000-313635 A Japanese Patent Laid-Open No. 2002-274883

  However, according to the inventor's study, in order to obtain a lower dielectric constant in the alkali borate glass, it is necessary to increase the amount of boron. However, a paste prepared using glass having such a composition range is used. When applied and baked, the thermal decomposability of the organic resin is reduced and the resulting dielectric film is colored brown as compared to the case of using a glass having a relatively low boron composition with a relative dielectric constant of about 7. When used in a display, there is a problem that display performance is remarkably deteriorated.

  In addition, when glass containing alkali is used as a dielectric material for protecting Ag and Cu, depending on the firing conditions, Ag and Cu are oxidized and ionized, and these ions diffuse in the glass and are reduced again. The colloidal metal is deposited and the dielectric layer and the glass substrate appear to be colored yellow, so-called yellowing occurs, and the display performance is deteriorated. That is, a low softening point glass having a low dielectric constant and hardly causing coloring has not been obtained.

  The present invention has a low softening point, a low dielectric constant, excellent thermal decomposability of the resin when used as a paste, and hardly causes yellowing, and is excellent in performance deterioration due to coloring when used in a display panel. An object of the present invention is to provide a glass composition capable of producing a display performance display.

The present invention includes at least B ₂ O ₃ , R ₂ O (R is one or more of Li, Na, and K) and V ₂ O ₅ , and the content of V ₂ O ₅ is 0.02 wt% or more. The low softening point glass composition is characterized by being 2% by weight or less and substantially free of lead. At this time, the content of B ₂ O ₃ is desirably 41 wt% or more and 90 wt% or less.

  The present invention also provides a display panel using the glass composition according to the present invention. The 1st display panel by this invention is a display panel by which the electrode is coat | covered with the dielectric material layer containing a glass composition, Comprising: This glass composition is the said glass composition by this invention. The second display panel according to the present invention has a dielectric layer containing a glass composition between a glass substrate and an electrode, and the glass composition contained in the dielectric layer is the glass composition according to the present invention. .

  The present invention also provides a PDP using the glass composition of the present invention. PDP electrode coating glass or partition wall forming glass is the glass composition according to the present invention.

  According to the present invention, the softening point is low, the dielectric constant is low, the resin is excellent in thermal decomposability when used as a paste and hardly yellowing, and when used in a display panel, performance deterioration due to coloring is unlikely to occur. A glass composition capable of producing a display having excellent display performance can be provided.

  As a result of detailed studies, the inventors have added vanadium oxide to reduce the thermal decomposability of the resin that occurs when the boron content is increased in order to lower the dielectric constant of the alkali borate glass. It was found that can be prevented by. It was also found that the addition of vanadium oxide has the effect of reducing yellowing.

If the amount of V ₂ O ₅ is limited to 0.02% by weight or more and 2% by weight or less, the effect of addition becomes unclear below this, and if it exceeds this, coloring of the glass itself due to containing vanadium will be deep. This is because it becomes.

B ₂ The O ₃ amount is 41 wt% or more and 90 wt% or less is desirable, if it less than this, not only the dielectric constant of the glass to be obtained is too low, and V ₂ for the pyrolysis of the resin is not so much reduced This is because the necessity of adding O ₅ is reduced, and conversely, coloring of the glass itself due to the inclusion of V ₂ O ₅ may become a problem, and if it is more than this, the glass becomes unstable.

If the glass of the present invention is composed of alkali metal, boron, vanadium, and oxygen, it is possible to obtain properties such as low dielectric constant, high thermal decomposability of the resin, and hardly causing yellowing. When used for an electrode-coated glass of a display such as PDP, it is desirable to include other components in order to optimize the glass transition temperature, thermal expansion coefficient, chemical durability, etc. according to the application. Components that can be included include SiO ₂ , ZnO, alkaline earth metal oxides (MgO, CaO, SrO, BaO) and the like. The addition of these components has the effect of increasing chemical durability, increasing the glass transition temperature, and reducing the thermal expansion coefficient. Examples of desirable composition ranges including these include:
0.02 wt% ≦ V ₂ O ₅ ≦ 2 wt%
41 wt% ≦ B ₂ O ₃ ≦ 90 wt%
3 wt% ≦ R ₂ O ≦ 25 wt% (R is one or more of Li, Na and K)
0 wt% ≤ MO ≤ 50 wt%
(M is one or more of Mg, Ca, Sr, Ba, Zn)
0 wt% ≦ SiO ₂ ≦ 26 wt%
If R ₂ O is less than this, the glass becomes unstable, and if it is more than this, the dielectric constant increases, and even if V ₂ O ₅ is added, it becomes difficult to suppress yellowing. % To 25% by weight is desirable.

  MO has the effect of increasing chemical stability, increasing the glass transition temperature and softening point, reducing the difference between the glass transition temperature and softening point, lowering the thermal expansion coefficient, and increasing the dielectric constant. 50% by weight or less is desirable because the softening point and the dielectric constant become too high.

SiO ₂ has the effects of increasing chemical stability, increasing the glass transition temperature and softening point, lowering the thermal expansion coefficient, and lowering the dielectric constant. The reason why it is preferably 26% by weight or less is that the softening point becomes too high.

Since the main purpose of the present application is to eliminate the poor thermal decomposability of the resin caused by alkali borate glass, particularly when the content of B ₂ O ₃ is large, by V ₂ O ₅ , elements other than the above, for example, Al, Addition of oxides such as Ti, Zr, La, Ce, Y, Mn, Nb, Ta, Te, Bi, Sb, P, Ag, Cu, etc. Is possible. However, it is known that Mn, Bi, Cu and the like are colored by addition of glass itself, and it is desirable that the addition amount be small. A desirable content is 5% by weight or less.

  It is preferable that the glass composition of the present invention does not substantially contain lead (Pb). In the present specification, “substantially free” means that it is industrially difficult to remove and allows a very small amount of the component that does not affect the properties. Specifically, the content is 1% by weight. % Or less, preferably 0.1% by weight or less.

In the present specification, the composition of the oxide glass is represented by the weight ratio of each component element as an oxide, as is generally done. However, this notation does not limit the valence of each cation in the glass. Vanadium oxide may also be contained in an amount of 0.02 wt% or more and 2 wt% or less in terms of V ₂ O ₅ .

  Next, a PDP will be described as a specific example of the display panel of the present invention. FIG. 1 is a partially cutaway perspective view showing the main configuration of the PDP according to the present embodiment. FIG. 2 is a cross-sectional view of this PDP. This PDP is an AC surface discharge type and has the same configuration as the PDP according to the conventional example except that the dielectric layer is formed of the glass composition described above.

  This PDP is configured by bonding a front plate 1 and a back plate 8 together. The front plate 1 is formed so as to cover the front glass substrate 2, the display electrode 5 composed of the transparent conductive film 3 and the bus electrode 4 formed on the inner side surface (the surface facing the discharge space 14), and the display electrode 5. The dielectric layer 6 and the dielectric protective layer 7 made of magnesium oxide formed on the dielectric layer 6 are provided. The display electrode 5 is formed by laminating a bus electrode 4 made of Ag or the like on a transparent conductive film 3 made of ITO or tin oxide in order to ensure good conductivity.

  The back plate 8 includes a back glass substrate 9, an address electrode 10 formed on one side thereof, a dielectric layer 11 formed so as to cover the address electrode 10, and a partition wall 12 provided on the top surface of the dielectric layer 11. And a phosphor layer formed between the barrier ribs 12. The phosphor layer is formed so that the red phosphor layer 13 (R), the green phosphor layer 13 (G), and the blue phosphor layer 13 (B) are arranged in this order.

For the dielectric layer 6 and / or the dielectric layer 11, preferably the dielectric layer 6, the glass composition according to the present invention described above is used. Moreover, you may use the glass composition of this invention as the partition 12. FIG. The dielectric layer 6 needs to be transparent, but the dielectric layer 11 and the partition wall 12 do not need to be transparent. Therefore, SiO ₂ having a lower dielectric constant is dispersed in the glass of the present invention as a filler. You may use what was contained. Further, although not shown here, if a layer containing the glass of the present invention is formed between the glass substrate and the display electrode 5 or between the glass substrate and the address electrode, the influence of the dielectric constant of the substrate glass can be reduced. Below, the case where the glass of this invention is used for the dielectric layer 6 is demonstrated as an example, However, The glass composition of this invention is used for the dielectric material layer 11, the partition 12, or the dielectric material layer between board | substrates / electrodes. Even in such a case, the glass composition of the present invention can be used favorably in a PDP because of the low dielectric constant, low softening point, high glass transition temperature, and appropriate thermal expansion coefficient.

As the phosphor constituting the phosphor layer, for example, BaMgAl ₁₀ O ₁₇ : Eu is used as a blue phosphor, Zn ₂ SiO ₄ : Mn is used as a green phosphor, and Y ₂ O ₃ : Eu is used as a red phosphor. it can.

  The front plate 1 and the back plate 8 are arranged so that the longitudinal directions of the display electrodes 5 and the address electrodes 10 are orthogonal to each other and face each other, and are joined using a sealing member (not shown).

  In the discharge space 14, a discharge gas (filled gas) made of a rare gas component such as He, Xe, or Ne is sealed at a pressure of about 66.5 to 79.8 kPa (500 to 600 Torr).

  The display electrode 5 and the address electrode 10 are each connected to an external drive circuit (not shown), and a discharge is generated in the discharge space 14 by a voltage applied from the drive circuit, and a short wavelength (wavelength generated by the discharge). The phosphor layer 13 is excited by ultraviolet rays of 147 nm and emits visible light.

  The dielectric layer 6 is usually made into a glass paste by adding a binder or a solvent for imparting printability to a glass powder, and this glass paste is applied onto an electrode formed on a glass substrate. It is formed by firing.

  The glass paste contains glass powder, a solvent, and a resin (binder), but other components such as a surfactant, a development accelerator, an adhesion assistant, an antihalation agent, a storage stabilizer, and an antifoaming agent. Additives according to various purposes such as an agent, an antioxidant, an ultraviolet absorber, a pigment, and a dye may be included.

  The resin (binder) contained in the glass paste is not particularly limited as long as it is generally used. For example, from the viewpoint of cost, safety, etc., cellulose derivatives such as nitrocellulose, methylcellulose, ethylcellulose, carboxymethylcellulose, polyvinyl Alcohol, polyvinyl butyral, polyethylene glycol, carbonate resin, urethane resin, acrylic resin, melamine resin, or the like may be used.

  The solvent in the glass paste is not particularly limited as long as it is generally used. From the viewpoint of cost, safety, etc., and from the viewpoint of compatibility with the binder resin, an appropriate organic solvent may be selected. These solvents may be used alone or in combination of two or more. Specifically, ethylene glycol monoalkyl ethers; ethylene glycol monoalkyl ether acetates; diethylene glycol dialkyl ethers; propylene glycol monoalkyl ethers; propylene glycol dialkyl ethers; propylene glycol alkyl ether acetates; Organic solvents such as esters; alcohols such as terpineol and benzyl alcohol; and the like can be used.

  Typically, the glass paste is applied by a screen method, a bar coater, a roll coater, a die coater, a doctor blade or the like, and baked. However, without being limited thereto, for example, it can be formed by a method of attaching and baking a sheet containing the glass composition.

  The thickness of the dielectric layer 6 is preferably about 10 μm to 50 μm in order to achieve both insulation and light transmittance.

  Next, a method for manufacturing the above PDP panel will be described with an example. First, a front plate is produced. A plurality of line-shaped transparent electrodes are formed on one main surface of the flat front glass substrate. Subsequently, after the silver paste is applied on the transparent electrode, the entire front glass substrate is heated, thereby baking the silver paste and forming the display electrode.

  A glass paste containing the dielectric layer glass in the PDP of the present invention is applied to the main surface of the front glass substrate by a blade coater method so as to cover the display electrodes. Thereafter, the entire front glass substrate is held at 90 ° C. for 30 minutes to dry the glass paste, and then baked at a temperature of about 580 ° C. for 10 minutes.

  Magnesium oxide (MgO) is deposited on the dielectric layer by an electron beam evaporation method and baked to form a protective layer. The firing temperature at this time is around 500 ° C.

  Next, a back plate is produced. After applying a plurality of silver pastes in a line on one main surface of a flat back glass substrate, the entire back glass substrate is heated and the silver paste is baked to form address electrodes.

  A partition wall is formed by applying a glass paste between adjacent address electrodes and firing the glass paste by heating the entire back glass substrate.

  By applying phosphor inks of R, G, and B colors between adjacent barrier ribs, and heating the back glass substrate to about 500 ° C. and baking the phosphor ink, a resin component in the phosphor ink (Binder) and the like are removed to form a phosphor layer.

  The front plate and the back plate thus obtained are bonded using a sealing glass. The temperature at this time is around 500 ° C. Thereafter, after the sealed interior is evacuated to high vacuum, a rare gas is sealed. A PDP is obtained as described above.

  The above-mentioned PDP and its manufacturing method are examples, and the present invention is not limited to this. As the PDP to which the present invention is applied, the surface discharge type as described above is typical, but the present invention is not limited to this and can be applied to a counter discharge type. Further, the present invention is not limited to the AC type, and can be applied to a DC type PDP having a dielectric layer.

  The glass composition of the present invention is not limited to PDP, but can be effectively used for a display panel that needs to be mixed with a resin to form a paste, and to perform a coating and baking process.

  The glass composition of the present invention is suitable for a display panel in which the electrode covered with the dielectric layer contains at least one selected from Ag and Cu. The electrode may be mainly composed of Ag.

  Hereinafter, the present invention will be described in more detail with reference to examples.

(Example 1)
As starting materials, oxides or carbonates of various kinds of metals of reagent grade or better were used. These raw materials were weighed so that the weight ratio in terms of each oxide was as shown in Table 1, mixed well, then placed in a platinum crucible and melted in an electric furnace at 900 to 1100 ° C. for 2 hours. . The obtained melt was quenched by pressing it with a brass plate to produce a glass cullet. The glass cullet was pulverized to an average particle size of about 2 to 3 μm, and the glass transition temperature and the softening point Ts were measured using a TG8110 macro differential thermal analyzer manufactured by Rigaku.

  Next, the glass cullet was remelted, poured into a mold, annealed at a temperature of glass transition temperature + 40 ° C. for 30 minutes, and then gradually cooled to prepare a glass block. From this glass block, a 4 mm × 4 mm × 20 mm rod was prepared by cutting, and a thermal expansion coefficient α between 30 ° C. and 300 ° C. was measured using a RGAKU TMA8310 type thermomechanical analyzer. In addition, a plate of 20 mm × 20 mm × thickness of about 1 mm was made from a glass block by cutting, and both surfaces were mirror-polished, and then a gold electrode was vapor-deposited on the surface. Using an impedance analyzer 4294A made by Agilent, the frequency was set to 1 kHz The capacitance was measured, and the relative dielectric constant ε was calculated from the area and thickness of the sample.

  Next, in order to evaluate the resin decomposability of the paste by the glass composition, a glass paste was prepared by mixing and dispersing the ethyl cellulose as a resin and α-terpineol as a solvent with three rolls into the produced glass powder. . This paste was applied onto a flat soda lime glass surface having a thickness of about 2.8 mm by using a blade coater method so that the thickness after firing was 30 μm, and the glass was kept at 90 ° C. for 30 minutes. The paste was dried, heated in air to a temperature of softening point + 10 ° C. over 1 hour, and held for 10 minutes to form a dielectric layer. The dielectric layer was observed to have a brown color due to the resin component remaining depending on the composition. Therefore, the transmittance at 500 nm was measured and used as a guide for this coloring.

  Further, in order to evaluate the ease of occurrence of yellowing due to the glass composition separately from the brown coloration due to the resin component residue of the above paste, 0.1% by weight of Ag powder was mixed with glass powder to which no resin was added, After molding with a mold, the compact was fired under the same conditions as the above paste, and the yellow coloration was observed with the naked eye, and was classified into four stages: no coloration, light coloration, medium coloration, and deep coloration. Yellowing should be judged by forming a silver electrode on a glass substrate, applying a glass paste from the glass substrate, drying it, and firing it. Since it is difficult to distinguish whether the color is due to low thermal decomposability, this simple discrimination method was used. It should be noted that for this glass composition in which yellowing was not recognized by this determination method and coloring was not recognized for the above resin decomposability, coloring did not occur even when a paste was applied on a silver electrode and baked. It was confirmed as shown in Example 2.

The results of each evaluation are shown in Table 1. In the table, the unit of the softening point Ts is ° C., and the unit of the thermal expansion coefficient α is × 10 ⁻⁷ / ° C. The transmittance is related to the above-described evaluation of resin decomposability, and the coloring is related to yellowing.

No. in Table 1 1-10, while increasing the amount of B ₂ O ₃ , other component amounts were adjusted so that the softening point for PDP was 590 ° C. or lower and the thermal expansion coefficient was 70-80 × 10 ⁻⁷ / ° C. It is a sample.

As is apparent from Table 1, No. 1 containing 41% by weight of B ₂ O _{3 was} obtained. 2 has a relative dielectric constant of less than 7, and a 45 wt. No. 3 was 6.5, 55 wt% No. No. 4 of 6.0, 60% by weight or more. In 5-10, it was less than 6.0. Therefore, in order to lower the relative dielectric constant, the amount of B ₂ O ₃ is 41% by weight or more, more preferably 45% by weight or more, further preferably 55% by weight or more, and further preferably 60% by weight or more. However, when the amount of B ₂ O ₃ exceeded 90% by weight, no. No. 10, the thermal expansion coefficient ^exceeded 80 × 10 ⁻⁷ / ° C. no matter how the ratio of other components was adjusted. Therefore, the amount of B ₂ O ₃ is desirably 90% by weight or less.

On the other hand, the transmittance decreased by the organic residue is No. 1 showed a high value of 78%. 2, it was less than 70, and as the amount of B ₂ O ₃ increased, it further decreased and it was clear that the organic resin residue increased.

Further, the coloration indicating the degree of yellowing tended to become thinner as the amount of alkaline components Li ₂ O and K ₂ O decreased, but did not disappear completely.

These No. No. 1 to 10 containing 0.2% by weight of V ₂ O ₅ was added. In 11-20, the transmittance | permeability improved with respect to the case where no addition was added, and coloring became thinner.

No. 5 and No. 5 No. 7 in which 0.01 to 3 wt% of V ₂ O ₅ was added to the composition of No. 7. 21-27, and In 28 to 34, when the added amount was 0.01% by weight, the effect of improving the transmittance and reducing the coloration was not clear, but when the added amount was 0.02% by weight or more, the effect was recognized. However, when the addition amount is 1.0% by weight or more, the transmittance decreases and the coloring starts to deepen. The samples at this time all exhibited a yellowish green color, which is thought to be because the organic residue was reduced and yellowing was less likely to occur, but the glass itself was colored by the addition of V ₂ O ₅ . Therefore, the amount of V ₂ O ₅ added is preferably 0.02% by weight or more, 2.0% by weight or less, and more preferably less than 1.0% by weight.

The inventor examined combinations of various compositions other than the above. Further, MgO, SrO and BaO were used instead of CaO, and Na ₂ O was used instead of Li ₂ O and K ₂ O. In either case, the amount of B ₂ O _{3 was} 41 to 90. By adding 0.02 to 2.0% by weight of V ₂ O ₅ to glass of wt%, low softening point glass with low dielectric constant, little organic residue during baking after pasting, and hardly causing yellowing It was possible to get

(Example 2)
In the same manner as in Example 1, the weight ratio of B ₂ O ₃ : ZnO: CaO: K ₂ O: V ₂ O ₅ = 72.5: 16.5: 2.5: 8.4: 0.1 For this purpose, various raw material powders were mixed and put in a platinum crucible and melted at 1100 ° C. for 2 hours in an electric furnace, and then a glass cullet was produced by a twin roller method. The glass cullet was pulverized by a dry ball mill to produce a powder. The average particle size of the obtained glass powder was about 3 μm. The relative dielectric constant of the present glass was 5.9, the glass transition temperature was 482 ° C., the softening point was 580 ° C., and the thermal expansion coefficient was 77 × 10 ⁻⁷ / ° C.

  To this powder, ethyl cellulose as a binder and α-terpineol as a solvent were added and mixed with three rolls to obtain a glass paste.

  Next, an ITO (transparent electrode) material was applied in a predetermined pattern on the surface of a front glass substrate made of flat soda-lime glass having a thickness of about 2.8 mm and dried. Next, a plurality of silver pastes, which are a mixture of silver powder and an organic vehicle, were applied in a line shape, and then the front glass substrate was heated, whereby the silver paste was baked to form display electrodes.

  The glass paste mentioned above was apply | coated to the front panel which produced the display electrode using the blade coater method. Thereafter, the front glass substrate was held at 90 ° C. for 30 minutes, the glass paste was dried, and baked at a temperature of 590 ° C. for 10 minutes to form a dielectric layer having a thickness of about 35 μm.

  The transmittance when converted to a thickness of 30 μm of the dielectric layer was 74%. In addition, the reflected color was measured using a color difference meter on the back surface side (side without electrodes) of the produced substrate. Note that natural light was used for the measurement and the measurement was corrected with a reference white plate. As a result, the a * value was −2.1, and the b * value was 3.8. The a * and b * are based on the L * a * b * color system. As the a * value increases in the positive direction, the red color increases, and when it increases in the negative direction, the green color increases. As the b * value increases in the positive direction, yellow increases, and when it increases in the negative direction, blue increases. In general, if the a * value is in the range of -5 to +5 and the b * value is in the range of -5 to +5, no coloration of the panel is observed. Therefore, it was confirmed that this dielectric layer was not colored to cause a problem.

  Magnesium oxide (MgO) was deposited on the dielectric layer by an electron beam deposition method, and then baked at 500 ° C. to form a protective layer.

  On the other hand, a back plate was produced by the following method. First, address electrodes mainly composed of silver were formed in a stripe shape on a rear glass substrate made of soda lime glass by screen printing, and then a dielectric layer having a thickness of about 40 μm was formed in the same manner as the front plate. .

  Next, partition walls were formed on the dielectric layer using glass paste between adjacent address electrodes. The partition was formed by repeating screen printing and baking.

  Subsequently, the phosphor layer of red (R), green (G), and blue (B) is applied to the surface of the dielectric layer exposed between the wall surfaces of the barrier ribs and the barrier ribs, and then dried and fired to phosphor layer Was made. The materials described above were used as the phosphor.

  The produced front plate and back plate were bonded at 500 ° C. using a Bi—Zn—B—Si—O-based sealing glass. Then, after the inside of the discharge space was evacuated to a high vacuum (1 × 10 −4 Pa), Ne—Xe-based discharge gas was sealed so as to have a predetermined pressure. In this way, a PDP was produced.

  It was confirmed that the produced panel operated without any problem without causing coloring or defects in the dielectric layer.

  The present invention can be suitably applied to the formation of a dielectric layer for covering insulating coating glass for electrodes, particularly display electrodes and address electrodes of plasma display panels.

The partial cutaway perspective view which shows an example of the structure of PDP by this invention Cross-sectional view of the PDP shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Front plate 2 Front glass substrate 3 Transparent conductive film 4 Bus electrode 5 Display electrode 6 Dielectric layer 7 Dielectric protective layer 8 Back plate 9 Back glass substrate 10 Address electrode 11 Dielectric layer 12 Partition 13 Phosphor layer 14 Discharge space

Claims (7)

At least B ₂ O ₃ , R ₂ O (R is one or more of Li, Na, and K) and V ₂ O ₅ , and the content of V ₂ O ₅ is 0.02 wt% or more and 2 wt% or less. A low softening point glass composition characterized by being substantially free of lead. _2. The low softening point glass composition according to claim 1, wherein the content of B ₂ O ₃ is 41 wt% or more and 90 wt% or less. A display panel in which electrodes are covered with a dielectric layer containing a glass composition, wherein the glass composition is the glass composition according to claim 1. A display panel comprising a first dielectric layer formed on a substrate, an electrode layer formed thereon, and a second dielectric layer formed thereon, wherein the first dielectric layer comprises: The display panel which is the glass composition of Claim 1 or 2. A front substrate on which a first electrode and a dielectric glass layer are formed; a second substrate on which a dielectric glass layer and a phosphor layer are formed; and the first electrode and the second electrode. The front substrate and the rear substrate are arranged so as to face each other with a predetermined distance apart, and a partition is installed between the front substrate and the rear substrate, and the front substrate, the rear substrate, and 3. A plasma display panel in which a dischargeable gas medium is enclosed in a space formed by the barrier ribs, wherein at least part of the dielectric glass layer on the first and second electrodes is defined in claim 1 or 2. A plasma display panel comprising the glass composition described above. A front substrate on which a first electrode and a dielectric glass layer are formed; a second substrate on which a dielectric glass layer and a phosphor layer are formed; and the first electrode and the second electrode. The front substrate and the rear substrate are disposed so as to face each other with a predetermined distance apart, and a partition is installed between the front substrate and the rear substrate, and the front substrate, the rear substrate, and A plasma display panel in which a dischargeable gas medium is enclosed in a space formed by the partition walls, wherein the partition walls include oxide glass, and at least a part of the oxide glass is defined in claim 1 or 2. A plasma display panel comprising the glass composition described above. The display panel according to claim 3, wherein the electrode includes at least one selected from silver (Ag) and copper (Cu).

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