CN102084453A - Plasma display panel - Google Patents

Abstract

Disclosed is a plasma display panel that can be expected to show excellent image display performance while requiring relatively low driving voltage. To this end, a chemical compound containing one or more rare earth metals, Sn, and oxygen is distributed as an electron emitting material (compound powders (20)) over a surface of a protective layer (7) facing a discharge space (14) in a PDP (200). The distributed compound is desirably a crystalline compound so that the stability thereof is increased. The crystalline compound includes Ln2Sn2O7 phase (Ln can include only one rare earth metal, or can include a plurality of rare earth metals). With this, an excellent secondary electron emission characteristic can be exhibited during driving, and the driving voltage of the PDP (200) can be reduced.

Description

Plasma display

Technical field

The present invention relates to a kind of plasma display (PDP), particularly relate to a kind of improving technology of protective layer periphery material.

Background technology

Plasma display (being designated hereinafter simply as PDP) according to easy maximization, can carry out that high speed shows, feature cheaply, and is practical and popularizes fast in slim display floater.

In the general PDP structure of current practicability, becoming a plurality of electrodes of systematicness being set respectively on 2 opposed glass substrates of front substrate and back substrate arranging (show electrode to or addressing electrode) respectively, so that the mode of these each covering electrodes on above-mentioned glass substrate is provided with dielectric layers such as low-melting glass.On the dielectric layer of substrate luminescent coating is set overleaf.On the dielectric layer of substrate the MgO layer is set in front, as being the protective layer of purpose with the bombardment by ions and the emission secondary electron of protection dielectric layer when not discharged.And, 2 substrates are carried out inner sealing across discharge space, and, in discharge space, enclose gas based on inert gases such as Ne, Xe.When driving, by between electrode, applying voltage so that discharge generation, thereby make light-emitting phosphor to show.

In PDP, the strong request high efficiency.As its scheme, the known method that the method that makes the dielectric layer low-kization is arranged, improve the Xe dividing potential drop of discharge gas.But, when using such scheme, have discharge inception voltage, keep the problem that voltage can rise.

On the other hand, if the known material that the high material of use secondary electron yield is arranged as protective layer then can reduce discharge inception voltage, keep voltage.Thus, can realize the cost degradation that uses high efficiency, withstand voltage low element to bring.Therefore, replace MgO,, studied and used secondary electron yield higher CaO, SrO, BaO or use their solid solution (with reference to patent documentation 1,2) each other though be identical alkaline-earth metals oxide.In addition, rare-earth oxide is also being studied as the diaphragm material.

The prior art document

Patent documentation

Patent documentation 1: Japanese kokai publication sho 52-63663 communique

Patent documentation 2: TOHKEMY 2007-95436 communique.

Summary of the invention

The problem that invention will solve

But CaO, SrO, BaO, rare-earth oxide etc. are compared with MgO chemically unstable, be easier to air in or in the panel residual moisture, carbon dioxide react, form hydroxide, carbonated.When forming such compound, the secondary electron yield of protective layer reduces, the problem of the effect of the lower voltage of the degree that existence can not obtain to expect.

The deterioration that causes for such chemical reaction is being made with the laboratory rank under the situation of a small amount of and small-sized PDP, can be avoided with the method for environment (atmosphere) gas of control operation.But, in reality, be difficult in manufacturing works, whole manufacturing processes be carried out environmental management, in addition, even may also can bring expensiveization.Particularly under the situation of making large-scale PDP, this problem is particularly remarkable.Therefore, although the use of the high material of secondary electron yield is being studied all the time, what be practical still has only MgO, be unrealized sufficient lower voltage, high efficiency.

In addition, under the situation that the material beyond the MgO is used as protective layer, because anti-bombardment by ions reduction, so the sputter quantitative change that the gas when PDP drives causes is big.Thus, the problem that has the lifetime of PDP.

The present invention makes in view of the above problems, thereby its purpose is to provide a kind of compound that has a good secondary electron emission characteristic by use can expect the PDP of performance excellent images display performance under low voltage drive.

The scheme that is used to deal with problems

In order to address the above problem, the present invention is following formation: a kind of PDP, it applies voltage and makes and discharge in discharge space between a plurality of electrodes, by utilizing fluorophor to be converted to visible light this discharge, thereby carry out luminous, wherein, in the zone that faces described discharge space, the compound of more than one of configuration packet rear earth containing metal, Sn and oxygen is as electronic emission material.

In the above-described configuration, preferably comprise rare earth metal more than one, the compound of Sn and oxygen is the crystallinity compound, and then, preferably by Ln ₂Sn ₂O ₇The compound of (Ln is more than one of rare earth metal) expression.

In addition, preferred rare earth metal is to be selected from more than one of La, Eu, Gd, Yb, Lu, in particular for La.And then, preferably with described compound with the state decentralized configuration of particle on the MgO protective layer.

And then; the present invention is a kind of PDP; it clips discharge space with first panel (front panel) and second panel (back panel) arranged opposite and constitute; wherein; described first panel (front panel) is to go up at first substrate (front glass substrate) to form first electrode (show electrode); form first dielectric layer that covers this first electrode; and the formation protective layer constitutes on described first dielectric layer; described second panel (back panel) is to go up at second substrate (back side glass substrate) to form second electrode (addressing electrode); form second dielectric layer that covers this second electrode; and the formation luminescent coating constitutes; wherein, described arbitrary electronic emission material of the present invention is contained in the described protective layer.

Perhaps; the present invention is a kind of PDP; it clips discharge space with first panel and the second panel arranged opposite and constitute; wherein; described first panel is to form first electrode on first substrate; form first dielectric layer that covers this first electrode; and the formation protective layer constitutes on described first dielectric layer; described second panel is to form second electrode on second substrate; form second dielectric layer that covers this second electrode; and the formation luminescent coating constitutes; wherein, make described arbitrary electronic emission material of the present invention with the state decentralized configuration of powder particle on described protective layer.

In addition, also can be following formation: also having with MgO with the state decentralized configuration of powder particle on described protective layer be the material of principal component.

The invention effect

According to the present invention, because in PDP, comprise rare earth metal more than one, the compound of Sn and oxygen is equipped on the zone that faces discharge space as electronic emission material, this compound is compared with existing MgO in stabilisation chemically, and the secondary electron yield height, so can provide the PDP that can drive preferable image display with low-voltage.

Perhaps; by using as substrate (base) as prior art that anti-bombardment by ions is the high MgO of protective layer; meanwhile; described compound is used as electronic emission material, thereby can provide driving voltage low and performance preferable image display performance and long PDP of life-span.

Description of drawings

Fig. 1 is used for the exploded perspective view that the formation to the PDP of execution mode 1 describes.

Fig. 2 is the sectional side elevation of PDP shown in Figure 1.

Fig. 3 is used for the exploded perspective view that the formation to the PDP of execution mode 2 describes.

Fig. 4 is the sectional side elevation of PDP shown in Figure 3.

Fig. 5 is the mensuration example of the valence band spectrum (valence band spectra) according to XPS.

Fig. 6 is the mensuration example according to the C1s spectrum of XPS.

Embodiment

＜about compound of the present invention 〉

The present application people etc. make secondary efficient height but chemically unsettled La ₂O ₃React Deng the raw material of rare-earth oxide and the oxide of various metals, synthesize and relate to multiple compound.And the result that this chemical stability and secondary ability are studied in detail is to make SnO ₂Under the situation of reaction, can under the situation that secondary efficient is not too reduced, improve stability chemically.And find, if use these compounds, then can obtain to compare the PDP of driving voltage reduction with the situation of using MgO.At this, terres rares is meant the general name of Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, but only exists radioisotopic Pm outside scope of the present invention.

As with more than any of terres rares, Sn, O be the compound of principal component, also can be the compound of noncrystalline (amorphous) state that comprises them.

But,, be preferably the crystallinity compound in order further to improve stability.

Can enumerate Ln as the crystallinity compound ₂Sn ₂O ₇Phase.As Ln, can be a kind of of rare earth metal, also can comprise multiple.

About selecting any of rare earth metal, it is not too high using its secondary efficient of compound of Sc, Y, and Sc is a high price in addition.Ce is difficult to become 3 valencys, with the synthetic of the compound of Sn and be not easy.In addition, its secondary efficient of rare earth metal that the f electronics is positioned at the valence band end is difficult to uprise, and heavy rare earth is generally high price.

From these viewpoints, be preferably La, Pr, Nd, Sm, Eu, Gd, particularly La is better.

This Ln ₂Sn ₂O ₇Be the composite oxides that have the crystal structure of fluorite type mutually, but the part displacement can be carried out with alkali earths in the site (site) of terres rares, or part is carried out with 4 such valency metals of Zr, Ce, 5 valency metals such as Nb, Ta, 3 valency metals such as In, Al etc. in the site of Sn replace, or O is carried out the part displacement with F.

Such displacement also can be carried out more than 2 kinds simultaneously.Wherein, when the part displacement is carried out with Ca, Sr, Ba as alkali earths in the site of terres rares, can further improve secondary efficient, so preferred.

But, when such displacement quantitative change for a long time, crystal structure can not be kept, and exists second to separate out the situation of separating or diminishing original characteristic mutually.In displacement was formed, final principal component also needed to be terres rares, Sn and O.

And then, in the common manufacturing process of not carrying out the environment adjustment, use Ln ₂Sn ₂O ₇Under the situation of phase, the total amount of preferred Ln is below 0.995 with the mol ratio Ln/Sn that cooperates of Sn.This general its reason of consideration is, even ratio is 1.000 situation, because the inhomogeneities of forming, thereby in the course of reaction of rare-earth oxide raw material and Sn oxide raw material, though rare-earth oxide is denier but has remainingly got off, under the condition of not carrying out the environment adjustment, carbonating and covering surfaces take place in it, and secondary electron yield has reduced.

In addition, under the situation of the site of terres rares site, Sn being carried out the displacement of above-mentioned part, will be set at below 0.995 in conjunction with the ratio of the total of these substitutional elements and get final product.In addition, when this ratio is reduced, at certain below the degree, SnO ₂Residue is also separated out, but in such state, owing to can prevent to become the many compositions of alkali earths as described above, so also can become and SnO ₂Mixture.

As the method for the oxide of synthetic more than one and the Sn that comprises rare earth metal, can enumerate solid phase method, liquid phase method, vapor phase method as its mode.

Solid phase method is to mix the material powder (metal oxide, metal carbonate etc.) that comprises each metal, and heat-treats the method that makes its reaction with certain temperature more than the degree.

Liquid phase method makes solid phase precipitation thus for making the solution comprise each metal, perhaps, behind this solution of coating on the substrate, carries out drying, heat-treats etc. and becomes the method for solid phase with certain temperature more than the degree.

Vapor phase method is the method that obtains membranaceous solid phase by methods such as evaporation, sputter, CVD.

In the present invention, also can use above-mentioned any method.If above-claimed cpd is used in the powder mode, the lower and also a large amount of easily solid phase methods of making of then usually preferred manufacturing cost.

Then, for which part that above-claimed cpd is equipped on PDP, as long as be provided in the zone that faces discharge space at least.On the general preferred dielectric layer that is provided in the electrode that covers front panel.But be not limited thereto, also can be formed at for example position such as fluorescence body, rib portion (rib) surface, other positions, or mix with fluorophor.Confirmed following content by experiment: by setting in the mode that compound is faced discharge space like this, thereby when comparing with the PDP that does not use above-claimed cpd, the effect that has driving voltage to reduce.

In addition, under the situation that sets above-claimed cpd on the luminescent coating, preferably with the suitable control amount of setting of the mode of the characteristics of luminescence of harmless fluorophor.

Then; mode about these compounds; for example when situation about forming on the dielectric layer of the electrode of considering to cover front panel; as long as adopt as shown in Figure 1, 2; the MgO film that replacement forms as common protective layer on dielectric layer and form the film of these compounds or the method that these powder are scattered, or as Fig. 3,4 be shown in and form after the MgO film the further film of these compounds of formation or the method that the powder of these compounds scatters is got final product.

But, form under the situation of these compounds replacing protective layer, though these compounds also for high-melting-point and be stable compound, yet compare with MgO, anti-sputter is poor slightly, the transparency is also poor slightly.Under the situation that powder scatters, also exist the transparency to reduce the problem of the deterioration in brightness that causes.

Therefore, be preferably as follows method: as protective layer, use the MgO film as prior art, and, powder is disperseed to scatter thereon with the rank that transmitance is no problem.

In order to become the no problem rank of transmitance, the lining rate of the protective layer that the powder of compound can be covered is made as below 20%.In addition, the particle diameter of powder is as long as wait selection matchingly with cell size (cell size) in the scope about 0.1 μ m～10 μ m.For example, in the situation of decentralized configuration, can particle diameter be made as below the 3 μ m in the mode that moves, falls to not producing of the powder on the MgO film, more preferably below the 1 μ m.If particle diameter is excessive, then the quality because of particle falls to the discharge space side sometimes, therefore should be noted that.

When making such formation, as protective layer as prior art, dystectic MgO film is brought into play its effect; for secondary, compound of the present invention is born this effect, and because its lining rate is low; so brightness can not descend yet, can obtain long PDP of low-voltage and life-span.

In addition, recently in order to solve the problem of the discharge delay that the height of following PDP becomes more meticulous, carried out following processing: will initial electronic transmitting efficiency good, crystalline MgO powder disperses distribution on the MgO protective layer.In this case, use method as follows: to MgO powder organic principle and make paste, after it being printed onto on the MgO protective layer, under suitable temperature, heat-treat, remove organic principle.

The powder of crystallized oxide of the present invention; owing to also can in identical processing, disperse to scatter; so though two kinds of above-mentioned cream can be printed respectively; but, comprise the powder of crystallized oxide of the present invention and the cream of crystalline MgO powder simultaneously if make, after it being printed onto on the MgO protective layer; under suitable temperature, heat-treat; remove organic principle, then can form, therefore be more preferably by single treatment.

Thus; become the effect that three kinds of i.e. protections of function, lower voltage, discharge delay that MgO film, crystallized oxide powder of the present invention, crystallinity MgO powder realize that respectively MgO film is in the past born are eliminated; best function can be used respectively, the PDP of superperformance can be made.

In addition, in this manual, compound is recited as Ln ₂Sn ₂O ₇But beyond 3 valencys, its part becomes divalent or becomes 4 valencys rare earth metal sometimes, can produce the excessive or not enough of oxygen in this case according to its kind.Therefore, though should more correctly be recited as Ln ₂Sn ₂O _{7 ± δ}, but this δ according to the kind of terres rares, create conditions etc. and change might not be fixed value.Therefore, though for convenience and as Ln ₂Sn ₂O ₇Put down in writing like that, but it is not to negate oxygen excess or not enough situation.

＜execution mode 1 〉

Then, use accompanying drawing that the concrete example of PDP of the present invention is described.

Fig. 1 and 2 is figure of the PDP100 of expression execution mode 1, and Fig. 1 is the exploded perspective view of this PDP100.Fig. 2 is the sectional side elevation (Fig. 1, I-I line profile) of this PDP100.

Shown in Fig. 1 and 2, PDP100 has front panel 1 and backplate 8.Be formed with discharge space 14 between plate 1 and the backplate 8 in front.This PDP is the AC surface discharge type, and protective layer 7 forms by above-mentioned compound is used as electronic emission material, in addition, has the formation same with the PDP of conventional example.

Front panel 1 possesses: front glass substrate 2, the show electrode 5 that is made of the nesa coating 3 that is formed at its medial surface (facing the face of discharge space 14) and bus electrode 4, the dielectric layer 6 that forms in the mode that covers show electrode 5 and be formed at protective layer 7 on the dielectric layer 6.Show electrode 5 is stacked on the nesa coating 3 that is made of ITO or tin oxide to be used to guarantee the bus electrode 4 that is made of Ag etc. of good electrical conductivity and to form.

Backplate 8 possesses: back side glass substrate 9, be formed at the addressing electrode (address electrode) 10 of its single face, the dielectric layer 11 that forms in the mode that covers addressing electrode 10, be arranged at dielectric layer 11 upper surface spaced walls 12 and be formed at luminescent coating between the spaced walls 12.Luminescent coating is with red-emitting phosphors layer 13(R), green-emitting phosphor layer 13(G) and blue phosphor layers 13(B) mode that is arranged in order forms.

Fluorophor as constituting above-mentioned luminescent coating for example, can use BaMgAl as blue emitting phophor ₁₀O ₁₇: Eu, can use Zn as green-emitting phosphor ₂SiO ₄: Mn, can use Y as red-emitting phosphors ₂O ₃: Eu.

Front panel 1 and backplate 8 are with show electrode 5 and addressing electrode 10 length direction separately is mutually orthogonal and mutual opposed mode disposes, and use seal member (not shown) to engage.

In discharge space 14, enclose the discharge gas that is made of rare gas compositions such as He, Xe, Ne is arranged.

Show electrode 5 is connected with the drive circuit (not shown) of outside respectively with addressing electrode 10, produce discharge by the voltage that applies from drive circuit at discharge space 14, the ultraviolet ray excited luminescent coating 13 by following the short wavelength (wavelength 147nm) that discharge produces also sends visible light.

In protective layer 7, comprise above-mentioned compound.At this, protective layer 7 can only be formed by above-claimed cpd, above-claimed cpd and MgO is mixed exist and formation protective layer 7.

In having the PDP100 of this formation, protective layer 7 is compared with prior art chemically being stablized, and, bring into play good secondary electron emission characteristic.Therefore, can under driving, low-power bring into play the preferable image display performance.

In addition, even owing to this PDP100 does not manage and can make whole environment of manufacturing process, so have the advantage that can realize at lower cost.

＜execution mode 2＞

Then, Fig. 3 and Fig. 4 represent the PDP200 of execution mode 2, and Fig. 3 is the exploded perspective view of this PDP200.Fig. 4 is the sectional side elevation (Fig. 3, I-I line profile) of this PDP200.

Among the PDP200, protective layer 7 is made of MgO, and above-mentioned compound powder 20 is configured on the protective layer 7 in the mode of particle, in addition, has the structure same with PDP100.In PDP200, also be compound powder 20 towards discharge space 14, dispose in the mode that faces this discharge space 14.

In the PDP200 that has such formation, also with PDP100 similarly, brought into play the effect of taking into account that the performance of excellent images display performance and low-power drive.In addition, by there being the layer 7 that constitutes by MgO, thereby also has the advantage of the various characteristics (the protection effect of the dielectric layer 6 that good anti-bombardment by ions brings and long lifetime etc.) of bringing into play this layer 7 simultaneously.

The manufacture method of＜PDP 〉

Then, for having made with the distribution of above-mentioned execution mode 1,2 explanations the PDP100 of compound powder, 200 method, enumerate an example and describe.In addition, the manufacture method of the PDP that the following describes is illustration only, can suitably change in same invention scope.

At first, make front panel.Form the transparency electrode 3 of a plurality of wire at an interarea of smooth front glass substrate 2.Then, behind coating silver paste on the transparency electrode 3, thereby, form bus electrode 4 and obtain show electrode 5 by with the whole heating of this substrate sintering silver paste.

Apply in the mode that covers show electrode 5 on the above-mentioned interarea of glass substrate 2 in front with scraper coating (blade coater) method and to comprise the glass cream of dielectric layer with glass., this substrate integral body with 90 ℃ kept 30 minute make glass cream drying, then, carry out 10 minutes sintering with about 580 ℃ temperature thereafter.Obtain dielectric layer 6 thus.

Then, under the situation of the formation that obtains PDP100, on dielectric layer 6, do not form the MgO protective layer, and above-mentioned compound is formed as thick film.Specifically, compound powder is mixed with carrier (vehicle), solvent etc., make the higher paste of compound powder containing ratio, it is coated in the surface of dielectric layer 6 than the unfertile land expansion with methods such as print processes.Carry out sintering, make the thick film shape thereafter.

On the other hand, under the situation of the formation that obtains PDP200, on dielectric layer 6, form MgO protective layer 7, scatter compound powder on its surface.At first, on dielectric layer,, form protective layer 7 by electron beam evaporation plating method film forming magnesium oxide (MgO).Then, set compound powder 20 on the surface of MgO protective layer 7.As this arrangement method; method as follows can routine be shown: prepare the lower cream of compound powder containing ratio; in the method by utilizing print process etc. to apply, make powder spread to method in the solvent, use the method etc. of spin coater etc. to be disposed at compound powder on the protective layer 7 after, its temperature with about 500 ℃ is carried out sintering.

Wherein, under situation, in ethyl cellulose carriers such as (ethyl cellulose), mix compound powder 20 of the present invention, the mixture of making paste is adjusted based on print process.It is coated on the MgO protective layer 7 by print process etc.After the cream coating, make its drying, carry out sintering with the temperature about 500 ℃.Thus, form the spread layer that constitutes by the compound powder of stipulating 20.

Made front panel by above processing.

Make backplate with the operation different with above-mentioned front panel.On the interarea of smooth back side glass substrate with many silver paste of wire coating after, back side glass substrate integral body is heated, and forms addressing electrode by the sintering silver paste.

Between adjacent addressing electrode, apply glass cream, and heating back side glass substrate integral body and sintered glass cream forms spaced walls thus.

Apply R, G, B fluorophor printing ink of all kinds each other in adjacent spaced walls, back side glass substrate is heated to about 500 ℃, above-mentioned fluorophor printing ink is carried out sintering, remove the interior resinous principle (adhesive) of fluorophor printing ink etc. thus, form luminescent coating.

Use seal glass to fit the front panel and the backplate that obtain like this.The temperature of this moment is about 500 ℃.Thereafter, the exhaust gas inside of sealing is high vacuum after, enclose the discharge gas of the regulation that constitutes by rare gas.

Each manufacturing process through above obtains the PDP100 that constitutes, 200 that is described by above-mentioned execution mode 1,2.

The performance evaluation experiment of＜embodiment 〉

Make compound and the PDP of embodiment, carry out performance evaluation.Below its content is elaborated.

(embodiment 1)

[compound synthetic and according to the evaluation of XPS]

In the present embodiment, to the material powder of the material powder that uses the rare earth metal oxide and tin oxide, narrate according to the synthetic of compound of the present invention of solid phase method.

As initiation material, use the above Ln of reagent superfine ₂O ₃Powder (because the kind of rare earth metal is more, so as Ln, this uses Y, La, Pr, Eu, Gd, Yb, Lu) and SnO ₂, CaCO ₃, SrCO ₃, BaCO ₃These raw materials are carried out weighing in the mode that the mol ratio of each metal ion becomes the ratio of table 1, use ball mill to carry out wet mixed after, carry out drying, obtain mixed-powder.

These mixed-powders are put into oxidation aluminum crucible, by electric furnace in air with 1200 ℃～1300 ℃ sintering 2 hours.For relatively, with the part of material powder, and the MgO powder carry out same processing.Use X-ray diffraction method to analyze in the powder that obtains, identify to generate phase.Show the result in table 1.

[table 1]

Make Ln ₂O ₃And SnO ₂Under the situation of reacting with the mol ratio of 1:1, all can confirm to have generated Ln ₂Sn ₂O ₇Phase.In addition, about to use La ₂O ₃As Ln ₂O ₃And the No.10-11 that the mode that its part is replaced with CaO, SrO, BaO cooperates also can confirm to obtain the La with No.2 ₂Sn ₂O ₇Identical diffraction pattern, and confirm of the generation of the part of La by the phase of Ca, Sr, Ba displacement.

Then, need to measure the secondary electron yield among the PDP, but powder is directly measured secondary electron yield and is not easy.As indirect evidence, reduce as long as confirm the discharge voltage of PDP, but to whole material PDP also and be not easy.

Therefore, the result that inventor etc. study in great detail is, utilize X-ray Photoelectron Spectroscopy(X X-ray photoelectron spectroscopy X) measure (below abbreviate XPS as), compare the energy position of valence electron band edge and the carbon amount that carbonate causes by mensuration, discovery can be selected the material of the discharge voltage reduction of the PDP that sends as an envoy to a certain extent.XPS measures to test portion surface irradiation X ray and to the spectrum of electrons emitted, and its analysis depth is made as several atoms～tens atomic layer usually, can obtain with PDP in secondary emission ratio surface information more approaching, test portion.

Secondary electron yield generally is made as energy gap and electron affinity and more little, and this coefficient is big more.The energy position of valence electron band edge is in low-yield side more, and energy gap is more little, and therefore, it is big that secondary electron yield becomes.

On the other hand, the carbon amount that causes of the carbonate on test portion surface is the index of chemical stability.If test portion then reacts with carbon dioxide in air chemically unstable, the surface carbon amount increases.When the surface carbon amount was how above to a certain degree, particle surface was covered fully by the carbonate of secondary electron yield.And, even for example the energy position of valence electron band edge is in low-yield side, can not obtain high secondary electron yield.

Therefore,, then compare the energy position of valence electron band edge and the carbon amount that carbonate causes, thereby can pick out the material of the discharge voltage reduction that can make PDP to a certain extent by mensuration if utilize XPS.

Therefore, by XPS synthetic powder is estimated.

Among Fig. 5, be La of the present invention for the test portion No.2,7,8,9 of table 1 ₂Sn ₂O ₇, and the La of comparative example ₂O ₃, SnO ₂, MgO illustrates the XPS spectrum of valence electron band edge.In addition, the XPS spectrum of the C1s track of these test portions shown in Figure 6.In the figure, the background correction noise is represented.

According to Fig. 5 as can be known, compare SnO with MgO ₂The valence band end position be in same degree, La ₂O ₃The valence band end position be in low-yield side a little, relative with it, La ₂Sn ₂O ₇The valence band end position obviously be in low-yield side.

On the other hand, in Fig. 6, the peak value of the C that carbonate compound causes appears near 288～290eV, but La ₂O ₃The peak value of C want high more than MgO, SnO ₂Peak value than the C of MgO is much lower.La ₂Sn ₂O ₇Compare SnO ₂The peak value height of C, but lower than the peak value of the C of MgO.

Because La ₂O ₃Should be than the secondary efficient height of MgO, so the valence band end position should more obviously appear at low-yield side in Fig. 5.But experimental result is not like this, and this general consideration is that the surface C amount is very many because as shown in Figure 6, and the surface has not been La ₂O ₃On the other hand, for SnO ₂, the C amount is few, but valence band end position and MgO do not have big difference.

Relative with it, generally consider for La ₂Sn ₂O ₇, because its surface C amount is certainly than La ₂O ₃Less but also lack than MgO, thus stabilisation, because the valence band end position is in low-yield side than MgO is obvious, so secondary efficient uprises.

In the table 1, for all cpds (test portion No.1～12) is measured XPS, and sxemiquantitative ground expression valence band end position and C amount, and the intensity (Intensity) (can expect that it is big more, secondary electron emission characteristic is good more in low-yield move) of the XPS among 3eV and the 2eV is shown in the lump and appears near the intensity (more little then chemically stable more) of the C1s peak value of the carbonate compound origin 288～290eV.This value is the value after the background correction value.

From the result shown in the table 1, can confirm that the XPS intensity of the 3eV of compound of the present invention (test portion No.1～6,10～12) and 2eV is all very big, and the C amount is few.In addition, with the part of the La of No.2 No.10～12 after with Ca, Sr, Ba displacement, compare with No.2, the XPS intensity of its 3eV and 2eV is bigger.

In addition,, also the displacement according to Ca, Sr, Ba of terres rares is studied, consequently can be obtained same effect for other composition system.Replacement amount for by Ca, Sr, Ba displacement the time, when surpass terres rares 10% the time, CaSnO ₃, SrSnO ₃, BaSnO ₃Begin mutually to generate as other, so 10% is the upper limit.

[making of PDP and driving voltage are measured]

Use has improved the compound of above-mentioned chemical stability and has made PDP as described below, and driving voltage is measured.

The front glass substrate that preparation is made of the smooth soda-lime glass of the about 2.8mm of thickness.Pattern coating ITO(transparency electrode to stipulate on the face of this front glass substrate) material carries out drying.Then, will as the silver paste of the mixture of silver powder and organic carrier with many of wire coatings after, above-mentioned front glass substrate is heated, the above-mentioned silver paste of sintering forms show electrode thus.

On the front panel of having made show electrode, use scraper coating process coating glass cream, and kept 30 minutes with 90 ℃, make the glass cream drying,, form the dielectric layer of the about 30 μ m of thickness thus with 585 ℃ temperature sintering 10 minutes.

On above-mentioned dielectric layer, behind electron beam evaporation plating method evaporation magnesium oxide (MgO), carry out sintering with 500 ℃, form protective layer thus.

Then, the powder of No.2 in the powder as shown in table 1 and No.3 is got about 1 weight portion, and mix, make cream by 3 rollers with carrier 99 weight portions of ethyl cellulose prime system.This cream is coated on the MgO layer than unfertile land by print process, and after carrying out drying with 120 ℃, in air, carries out sintering with 500 ℃.At this moment, by adjusting the concentration of cream, will be set at about 10% by the be covered ratio of the MgO film behind the sintering of powder.In addition, for relatively, only also made No.7,8 La ₂O ₃And SnO ₂Powder carries out the material of livering and printing, sintering and the substrate MgO film material that do not carry out cream printing only equally.

On the other hand, make backplate by following method.At first, form addressing electrode, then,, form the dielectric layer of the about 8 μ m of thickness by the method same with front panel based on silver by silk screen printing striated ground on the back side glass substrate that constitutes by soda-lime glass.

Then, on dielectric layer, use glass cream between adjacent addressing electrode, to form spaced walls.Spaced walls forms by repeating silk screen printing and sintering.

Then, the fluorophor cream of coating red (R), green (G), blue (B) on the surface of the dielectric layer between wall that is exposed to spaced walls and spaced walls, drying and sintering and make luminescent coating.

Use seal glass with 500 ℃ of applyings front panel, the backplate made.And, the inside of discharge space carried out exhaust after, enclose Ne-Xe as discharge gas, make PDP.

Each PDP after making is connected in drive circuit makes it luminous, after under luminance, keeping wearing out in 3 hours, voltage is kept in discharge measured.At this, burin-in process is in order by sputter MgO film, the surface of scattering powder to be carried out to clean to a certain degree, can to implement usually in the manufacturing process of PDP, and the panel that does not carry out it is pipe powder having or not of scattering not, and driving voltage is all high.

Show the result in table 2.In addition, No.0 only has the measurement result that the PDP of MgO basilar memebrane carries out to not carrying out powder to scatter.

[table 2]

As shown in table 2, compare with the No.0 that has only the MgO film, in the distribution of embodiment among the panel No.2,3,11 of oxide, obviously find the reduction of driving voltage.In addition, when comparing No.2 and 11, the driving voltage of No.11 is low a little.Can confirm terres rares is carried out the effect that the part displacement obtains with Ca, Sr, Ba according to this result.

On the other hand, the distribution of comparative example La ₂O ₃No.7 and have only the No.0 of basilar memebrane almost not find difference on the driving voltage.La ₂O ₃Should be secondary efficient height, and be lower voltage, but general consider it is that the C amount on surface is many that its surface can not fully clean in carry out usually about 3 hours aging, does not have lower voltage.

In addition, scattering SnO ₂No.8 in, though reason and unclear does not have luminous in aging way.

In PDP, make compound of the present invention face discharge space obviously as can be known according to above, thereby can obtain the effect that driving voltage descends by being adapted to.

Utilizability on the industry

Can extensively be used in communal facility and the home-use TV etc. according to PDP of the present invention, can provide the advantages such as PDP of having improved flash-over characteristic owing to have, so its utilizability can be described as very widely.

Description of reference numerals

1 front panel; 2 front glass substrates; 3 nesa coatings; 4 bus electrodes; 5 show electrodes; 6 dielectric layers; 7 protective layers; 8 backplates; 9 back side glass substrates; 10 addressing electrodes; 11 dielectric layers; 12 spaced walls; 13 luminescent coatings; 14 discharge spaces; 20 compounds; 100,200 plasma displays (PDP).

Claims (according to the modification of the 19th of treaty)

1.(revise the back) a kind of plasma display, it applies voltage and makes and discharge in discharge space between a plurality of electrodes, by utilizing fluorophor to be converted to visible light this discharge, thereby carry out luminous, wherein,

In the zone that faces described discharge space, the crystallinity compound of more than one of configuration packet rear earth containing metal, Sn and oxygen,

Described crystallinity compound is by Ln ₂Sn ₂O ₇The compound (wherein, Ln represents more than one of rare earth metal) of expression.

2.(deletion).

3.(deletion).

4.(revise the back) plasma display according to claim 1, wherein, described rare earth metal is to be selected from more than one of La, Eu, Gd, Yb, Lu.

5.(revise the back) according to claim 1 or 4 described plasma displays, wherein, described rare earth metal is La.

6.(revise the back) according to each described plasma display in the claim 1,4,5, wherein, the part of described rare earth metal is by partly displacement more than any of Ca, Sr, Ba.

7. according to each described plasma display in the claim 1,4,5,6, wherein,

Described plasma display clips discharge space arranged opposite first panel and second panel and constitutes; wherein; described first panel covers first dielectric layer of this first electrode and form protective layer on described first dielectric layer in formation first electrode, formation on first substrate and constitutes; described second panel forms second electrode on second substrate, formation covers second dielectric layer of this second electrode and forms luminescent coating and constitutes

Described crystallinity compound is contained in the described protective layer.

8. plasma display according to claim 7, wherein, also having with MgO with the state decentralized configuration of powder particle on described protective layer is the material of principal component.

9.(revise the back) according to each described plasma display in the claim 1,4,5,6, wherein,

Described plasma display clips discharge space arranged opposite first panel and second panel and constitutes; wherein; described first panel covers first dielectric layer of this first electrode and form protective layer on described first dielectric layer in formation first electrode, formation on first substrate and constitutes; described second panel forms second electrode on second substrate, formation covers second dielectric layer of this second electrode and forms luminescent coating and constitutes

Described crystallinity compound with the state decentralized configuration of powder particle on described protective layer.

10. plasma display according to claim 9, wherein, also having with MgO with the state decentralized configuration of powder particle on described protective layer is the material of principal component.

Claims (10)

1. plasma display, it applies voltage and makes and discharge in discharge space between a plurality of electrodes, by utilizing fluorophor to be converted to visible light this discharge, thus carry out luminous, wherein,

In the zone that faces described discharge space, the compound of more than one of configuration packet rear earth containing metal, Sn and oxygen.

2. plasma display according to claim 1, wherein, described compound is the crystallinity compound.

3. plasma display according to claim 2, wherein, described crystallinity compound is by Ln ₂Sn ₂O ₇The compound (wherein, Ln represents more than one of rare earth metal) of expression.

4. according to each described plasma display in the claim 1～3, wherein, described rare earth metal is to be selected from more than one of La, Eu, Gd, Yb, Lu.

5. according to each described plasma display in the claim 1～3, wherein, described rare earth metal is La.

6. according to each described plasma display in the claim 1～3, wherein, the part of described rare earth metal is by partly displacement more than any of Ca, Sr, Ba.

7. according to each described plasma display in the claim 1～3, wherein,

Described plasma display clips discharge space arranged opposite first panel and second panel and constitutes; wherein; described first panel covers first dielectric layer of this first electrode and form protective layer on described first dielectric layer in formation first electrode, formation on first substrate and constitutes; described second panel forms second electrode on second substrate, formation covers second dielectric layer of this second electrode and forms luminescent coating and constitutes

Described compound is contained in the described protective layer.

8. plasma display according to claim 7, wherein, also having with MgO with the state decentralized configuration of powder particle on described protective layer is the material of principal component.

9. according to each described plasma display in the claim 1～3, wherein,

Described plasma display clips discharge space arranged opposite first panel and second panel and constitutes; wherein; described first panel covers first dielectric layer of this first electrode and form protective layer on described first dielectric layer in formation first electrode, formation on first substrate and constitutes; described second panel forms second electrode on second substrate, formation covers second dielectric layer of this second electrode and forms luminescent coating and constitutes

Described compound with the state decentralized configuration of powder particle on described protective layer.

10. plasma display according to claim 9, wherein, also having with MgO with the state decentralized configuration of powder particle on described protective layer is the material of principal component.

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