CN101414531A - Plasma display panel and method for manufacturing same - Google Patents

Abstract

The invention relates to a plasma display panel wherein a first substrate (11) provided with a protective layer (15) is so arranged as to face a second substrate with a discharge space therebetween and the peripheries of the two substrates are sealed and bonded together is disclosed. The first material and the second material are exposed to the discharge space, and at least one of the first and second materials exists in a dispersed state. The first material and the second material may respectively be a first crystal (15A) and a second crystal (15B), and the surface of the protective layer may be composed of the first crystal in which the second crystal is dispersed.

Description

Plasma display and manufacture method thereof

The application be application number to be 200380109088.0 (PCT/JP2003/014349), denomination of invention be the dividing an application of female case of " plasma display and manufacture method thereof ", the applying date of this mother's case is on November 12nd, 2003.

Technical field

The present invention relates to the manufacture method of gas discharge panels such as plasma display, particularly the improvement technology of dielectric layer.

Background technology

Plasma display (to call PDP in the following text) is the gas discharge panel that the ultraviolet ray exited light-emitting phosphor that utilizes gas discharge to produce comes display image.According to the formation method of this discharge, PDP can be divided into AC type (AC) and direct current (DC) type, because of the AC type is more superior than DC type at aspects such as brightness, luminous efficiency, life-spans, so adopt this type usually.

The structure of AC type PDP is to dispose the surface of a plurality of electrodes (show electrode or address electrode) with 2 blocks of thin panel glass of the dielectric layer that covers this electrode, to dispose by a plurality of barrier ribs are relative, and between these a plurality of barrier ribs, dispose luminescent coating, form rectangular discharge cell (subpixel), under this state, between two panels glass, enclose discharge gas.Surface at the dielectric layer that covers show electrode forms protective layer (film).The preferred discharge inception voltage Vf of the characteristic of protective layer (Firing Voltage, ignition voltage) is low, and the few characteristic of generation of the discharge difference of each discharge cell.The crystalline film of MgO is the insulator that anti-sputter is good and secondary electron yield is big, is suitable as the material of protective layer.

In PDP, cut apart the gray scale display mode according to the time in the field, when driving, in discharge gas, produce discharge by above-mentioned a plurality of electrodes are supplied with suitable voltages and make it send fluorescence.Specifically, when PDP drives, at first the frame that shows is divided into a plurality of subframes, so with each subframe be divided into a plurality of during.In each subframe, during initialization, make the wall electric charge initialization (resetting) of whole image, then during the address only at the discharge cell that should light, discharged in the address of savings wall electric charge, during discharge is thereafter kept, by all discharge cells being applied simultaneously alternating voltage (keeping voltage), keep the discharge of certain hour.The discharge of carrying out because of PDP takes place by probability, so the incidence (being called discharge probability) of each discharge cell discharge has difference usually.Therefore, according to this characteristic, the address discharge is proportional with the width of the pulse of the executive address discharge that is applied, thereby can improve discharge probability.

About the general formation of PDP, disclosed by for example opening flat 9-92133 communique etc. the spy.

Here, the protective layer that is formed by MgO uses in order to realize low voltage operating, but compare operating voltage with liquid crystal indicator etc. still high.Therefore, must use high-voltage transistor in drive integrated circult, this is to make one of reason that the cost of PDP improves.Therefore, current, in order to reduce the power consumption of PDP, require to reduce discharge ionization voltage Vf, suppress use simultaneously to expensive high-voltage transistor.

On the other hand, as the film forming of the MgO of protective layer, except film forming methods such as vacuum vapour deposition, EB method, sputtering method, can also utilize print process (thick film forming method) of having used as the organic material of the predecessor of MgO etc. to carry out.Wherein, print process for example the spy to open flat 4-10330 communique disclosed like that, the organic material of liquid is mixed with glass material, and it is spin-coated on the surface of face glass, by about 600 ℃ roasting, make MgO crystallization formation protective layer.Compare with vacuum vapour deposition, EB method or the low-priced method of penetrating, print process has the advantage that operation is simple, cost is low, and because needing no vacuum technology, so, from the production capacity aspect, also have advantage.

But; compare with the protective layer that in the film forming method, uses vacuum technology to form; though the protective layer that forms with the thick film forming method causes the discharge difference between each discharge cell easily not having big difference aspect the effect that reduces discharge inception voltage Vf when PDP drives.Because this discharge difference can produce what is called " black noise ", is difficult to obtain the preferable image display performance, so, be to wish improved problem.Black noise is the phenomenon that the discharge cell (selected discharge cell) that should light is not lighted, and produces on the border in picture mid point clear zone and non-some clear zone easily.Because the position of not lighting disperses very much, rather than all can't light along 1 row of the long side direction of show electrode or along all unit selected in 1 row of the long side direction of 2 adjacent barrier ribs, so, the reason that produces black noise is considered to not take place the address discharge, even or taken place but insufficient strength.The reason of this phenomenon occurs and confidential relation is arranged from the magnesium oxide electrons emitted.

In addition; problem about PDP discharge difference is not limited to use the thick film forming method to form the situation of protective layer; for the film forming method; when using oxygen defect partly few (being oxygen enrichment) when MgO forms protective layer; also be easy to generate discharge difference; so,, all be badly in need of addressing this problem no matter being to use thick-film formation method still is that film formation method is carried out film forming.

The present invention proposes in view of the above problems, thus its purpose be to provide a kind of cost low and also can high efficiency by reducing discharge inception voltage Vf and the difference that reduces to discharge drives the PDP and the manufacture method thereof of the excellent image display performance of performance.

Summary of the invention

In order to address the above problem, the present invention is a kind of plasma display, and wherein, the 1st substrate that has formed protective layer disposes through discharge space is relative with the 2nd substrate, and sealed around above-mentioned two substrates; On the surface of protective layer, mutually different the 1st material of electron emission characteristic and the 2nd material are exposed to above-mentioned discharge space respectively, and at least one side in the 1st material and the 2nd material disperses to exist.

Here, above-mentioned the 1st material is the 1st crystalline solid, and above-mentioned the 2nd material is the 2nd crystalline solid, can constitute on the surface of above-mentioned protective layer, the 2nd crystalline solid is dispersed in the 1st crystalline solid.

At this moment, the preferred purity of above-mentioned the 2nd crystalline solid is higher than the material of above-mentioned the 1st crystalline solid.

In addition, above-mentioned protective layer of the present invention is mainly formed by magnesium oxide, and above-mentioned the 2nd crystalline solid is formed by magnesian crystal fine grain.

On the other hand, the 1st crystalline solid can obtain by the predecessor of roasting oxidation magnesium.

According to the present invention, for example, the characteristic that the discharge ionization voltage Vf of protective layer reduces can be brought into play by the magnesium oxide crystalline solid of the 1st crystalline solid and the magnesian crystal fine grain both sides of the 2nd crystalline solid.

Promptly; when PDP drives; utilize the inner electric field excitation discharge gas that takes place of discharge space; when the rare-gas atom in the discharge gas is surperficial near protective layer; produce so-called Auger effect; electron transfer in the valence band of protective layer, thus, other electronics in the protective layer is launched to the discharge space electromotive force.As a result, because of having given play to secondary electron emission characteristic well, so discharge inception voltage Vf reduces.By the electron potential emission that produces because of this protective layer,, also can make protective layer obtain desired secondary electron emission characteristic (γ) even the electron emission characteristic of magnesium oxide crystalline solid is poor slightly.Therefore, for magnesium oxide crystalline solid of the present invention,, also can obtain obvious effects even utilize the employed predecessor of magnesium oxide cheaply when in the working procedure of coating of thick film forming method, making protective layer.

Secondly, relevant with the discharge difference that suppresses protective layer characteristic can be by bringing into play the magnesium oxide crystal fine grain that improves electron emission characteristic because of having highly purified crystalline texture.That is, when producing electric field in discharge space, utilize the vacuum ultraviolet of following (VUV), at first, the electronics in the magnesium oxide crystal fine grain partly moves to oxygen defect.Then, utilize the electron energy of this oxygen defect part poor, as luminescence center, send visible light with the oxygen defect part.Follow the luminous of this visible light, in the magnesium oxide crystal fine grain, produce near energy level (impurity is with reference to the energy level) electrons excited of the valence band conduction band.By increasing the electronics of this impurity, can improve the carrier concentration of protective layer, control group with reference to energy level.As a result, the discharge difference in the time of can suppressing the PDP driving, the discharge probability of raising PDP can prevent the generation of black noise simultaneously, performance preferable image display performance.

Description of drawings

Fig. 1 is the part sectioned view of main composition of the PDP of expression execution mode 1.

Fig. 2 is the figure of the driving process example of expression PDP.

Fig. 3 is the figure of formation of the protective layer of expression execution mode 1.

Fig. 4 is the figure of formation of the protective layer of expression execution mode 2.

Fig. 5 is the energy band diagram of protective layer.

Fig. 6 is the part sectioned view of main composition of the PDP of expression execution mode 3.

Fig. 7 is the figure of the photoelectronic spectroscopic data of expression MgO and Al.

Fig. 8 is being with of magnesium oxide and Al.

Fig. 9 is the pie graph of the protective layer that formed by the complex of magnesium oxide and other materials or composite material.

Figure 10 is the part sectioned view of primary structure of the PDP of expression execution mode 4.

Preferred implementation

1, execution mode 1

The formation of 1-1, PDP

Fig. 1 is the part section oblique view of main composition of the AC type PDP1 of expression embodiment of the present invention 1.Among the figure, the Z direction is equivalent to the thickness direction of PDP1, and the xy plane is equivalent to the plane parallel with the face of PDP1 panel.Here as an example, the specification of PDP1 meets the NTSC standard of 42 inches grades, but the present invention also is applicable to other specifications such as XGA or SXGA.

As shown in Figure 1, the formation of PDP1 roughly can be divided into front panel 10 and the rear board 16 that interarea faces one another setting.

On a interarea, form many to show electrode 12,13 (scan electrode 12, keep electrode 13) as the front panel glass 11 of the substrate of front panel 10.Each show electrode the 12, the 13rd is by by ITO or SnO ₂The banded transparency electrode 120,130 (thick 0.1 μ m, wide 150 μ m) that forms Deng the transparent conductivity material goes up the bus 121,131 (thick 7 μ m, wide 95 μ m) that lamination forms by Ag thick film (thick 2 μ m～10 μ m), aluminium (Al) film (thick 0.1 μ m～1 μ m) or Cr/Cu/Cr lamination film (thick 0.1 μ m～1 μ m) etc. and forms.The electrical sheet resistance of transparency electrode 120,130 reduces because of this bus 121,131.

On the front panel glass 11 of configuration show electrode 12,13, utilize silk screen print method etc. on the whole interarea of this glass 11, to form with lead oxide (PbO), bismuth oxide (Bi ₂O ₃) or phosphorous oxide (PO ₄) be the dielectric layer 14 of the low-melting glass (thick 20 μ m～50 μ m) of main component.Dielectric layer 14 has the distinctive current limit function of AC type PDP, and this is its life-span factor longer than the life-span of DC type PDP.The protective layer 15 of the about 1.0 μ m of cladding thickness successively on the surface of dielectric layer 14.

The principal character of present embodiment 1 is that protective layer 15 is made of the magnesium oxide with the mutually different 2 kinds of structures of electron emission characteristic.Promptly; shown in the front view of the protective layer of Fig. 3; at the surface portion of the protective layer 15 that is exposed to following discharge space 24, disperse to have that the predecessor roasting that contains organic material forms as the magnesium oxide crystalline solid 15A of the 1st material and before above-mentioned predecessor roasting the magnesium oxide crystal fine grain 15B as the 2nd material of pre-crystallization.

If according to this formation; can reduce discharge inception voltage Vf well by magnesium oxide crystalline solid 15A and magnesium oxide crystal fine grain 15B during driving; on the other hand, can bring into play the electron emission characteristic of protective layer 15 by magnesium oxide crystal fine grain 15B, thereby obtain the preferable image display performance.The details of this effect will be narrated in the back.

On a interarea as the rear board glass 17 of the substrate of rear board 16, with the x direction as long side direction, be a plurality of address electrodes 18 that strip is set up in parallel the wide 60 μ m that formed by Ag thick film (thick 2 μ m～10 μ m), aluminium (Al) film (thick 0.1 μ m～1 μ m) or Cr/Cu/Cr lamination film (thick 0.1 μ m～1 μ m) etc. in the y direction by certain interval (360 μ m), the dielectric film 19 of the thick 30 μ m of coating on whole rear board glass 17 makes this address electrode 18 of bag in it.And then, on dielectric film 19, barrier rib 20 (high about 150 μ m, wide 40 μ m) is set corresponding to the gap of neighbor address electrode 18, utilize the barrier rib 20 of adjacency to divide subpixel SU, misplace electricity or optical crosstalk with what prevent the x direction.Then, on the face of the side of adjacent 2 barrier ribs 20 and dielectric film 19 therebetween, be formed for colored that show, respectively with red (R), green (G), blue (b) corresponding luminescent coating 21～23.

In addition, also can not use dielectric film 19 and directly use packet address electrode 18 in the luminescent coating 21～23.

Front panel 10 and rear board 16 are faced and are provided with, make the long side direction of address electrode 18 and show electrode 12,13 mutually orthogonal, and the outer peripheral edges portion of two panels 10,16 is by frit-sealed.Between this two panels 10,16, use the pressure (normally about 53.2kPa～79.8kPa) of regulation to enclose the discharge gas (inclosure gas) that constitutes by inert gas compositions such as He, Xe, Ne.

Be discharge space 24 between the adjacent barrier rib 20,12,13 and 1 address electrodes 18 of adjacent a pair of show electrode are corresponding with the subpixel SU of image demonstration with the be clipped in the middle zone that intersects of discharge space.Unit interval is x direction 1080 μ m, y direction 360 μ m.1 pixel (1080 μ m x, 1080 μ m) is made of 3 adjacent RGB subpixel SU.

The elemental motion of 1-2, PDP

The PDP1 of above-mentioned formation is driven by the drive division (not shown) to show electrode 12,13 and address electrode 18 power supplies.When being used for the driving of image demonstration, gap between a pair of show electrode 12,13 is applied the AC voltage of tens of kHz～hundreds of kHz, make to produce discharge in the subpixel SU, the ultraviolet ray excited luminescent coating 21～23 that the Xe atom that utilization is excited sends makes it send visible light.

At this moment, at above-mentioned drive division,, for example will be divided into 6 subframes as each frame F of seasonal effect in time series from the input picture of outside for 2 systems that utilize ON/OFF are controlled the luminous and representing gradation of each unit.Luminance weighted by in each subframe, making the relative ratios of brightness for example is 1:2:4:8:16:32, sets the number of light emission times of keeping (keeping discharge) of each subframe.

Fig. 2 is the example that the drive waveforms of this PDP1 is handled.The drive waveforms of m subframe in the frame is shown here.As shown in Figure 2, during each subframe is divided into initialization respectively, during the address, discharge keep during and between erasing period.

During the initialization be the influence (influence of the wall electric charge of savings) of lighting for the unit that prevents before this and with the wall electric charge of whole image eliminate (initialization discharge) during.In waveform example shown in Figure 2, all show electrodes 12,13 are applied reset pulse above the decline ramp waveform with positive polarity of discharge inception voltage Vf.Meanwhile, in order to prevent the charged and ionic bombardment of rear board 16 sides, all address electrodes 18 are applied positive pulse.Utilization applies the differential voltage of the rising edge and the trailing edge of pulse, produces the initialization discharge as weak surface discharge in all unit, and savings wall electric charge makes whole image be in the uniform charged state in all unit.

During the address be to according to the picture signal that has been divided into subframe to selected unit carry out addressing (setting of lighting/not lighting) during.During this period, scan electrode 12 is applied earthy positive potential biasing that connects, all electrodes 13 of keeping are applied the negative potential biasing.Under this state, from the initial row (unit of horizontal row corresponding) on panel top, select each row in order line by line with a pair of show electrode, corresponding scan electrode 12 is applied the scanning impulse of negative polarity.In addition, to applying the address pulse of positive polarity with the unit corresponding address electrode 18 that should light.Thus, the weak surface discharge during the above-mentioned initialization of row of going on, the only corresponding unit of lighting carries out the address discharge, savings wall electric charge.

Discharge is during the discharge of the illuminating state of being set by the address discharge being amplified in order to ensure the brightness corresponding with tonal gradation is kept during keeping.Here, in order to prevent unnecessary discharge, all address electrodes 18 are applied the biasing of positive polarity current potential, all electrodes 13 of keeping are applied positive polarity and keep pulse.Then, to scan electrode 12 with keep electrode 13 and alternately apply and keep pulse, discharge repeatedly in specified time limit.

Between erasing period, scan electrode 12 is applied decaying pulse gradually, to wipe the wall electric charge.

Have, the length during during the initialization and the address and the weight of brightness are irrelevant, are fixed values again, but the length of discharging during keeping then increases with the increase of luminance weights.That is, the length during the demonstration of each subframe is different.

In PDP1, utilize each discharge that subframe carries out, produce result from Xe, have at the 147nm place resonance line of sharp-pointed peak value and form by molecular beam, be the vacuum ultraviolet at center with 173nm.This vacuum ultraviolet shines each luminescent coating 21～23, produces visible light.Make up by the versicolor subframe unit of RGB, carry out the demonstration of multiple color, multi-stage grey scale.

The effect of 1-3, execution mode 1

The flash-over characteristic of PDP depends on the flash-over characteristic of the protective layer 15 that contacts with discharge gas to a great extent in discharge space 24.The characteristic that protective layer is required comprises the characteristic (secondary electron emission characteristic) that reduces discharge inception voltage Vf and relates to the characteristic that suppresses discharge difference; This two specific character is good more, and the image display performance of PDP is good more.

Here; in the PDP1 of present embodiment 1; in order to guarantee above-mentioned two characteristics effectively simultaneously; shown in the front view of the protective layer of Fig. 3; on the surface of the protective layer 15 that is exposed to discharge space 24 at least, there be magnesium oxide crystalline solid 15A and magnesium oxide crystal fine grain 15B dispersedly with different mutually electron emission characteristics.Magnesium oxide crystalline solid 15A forms by the magnesium oxide predecessor of roasting organic material.On the other hand, magnesium oxide crystal fine grain 15B is the material of crystallization in advance before above-mentioned predecessor roasting, compares with magnesium oxide crystalline solid 15A to have high-purity crystallized structure.Here, the formation of the protective layer of Fig. 3 is that magnesium oxide crystal fine grain 15B with the 2nd crystalline solid is dispersed among the magnesium oxide crystalline solid 15A of the 1st crystalline solid.

According to this formation, at first, reduce the characteristic of the discharge inception voltage Vf of protective layer 15 and bring into play by magnesium oxide crystalline solid 15A and magnesium oxide crystal fine grain 15B.

That is, when PDP drives, utilize the discharge space 24 inner electric fields that produce to excite discharge gas, the Ne in discharge gas ⁺During near the protective layer surface, produce so-called Auger effect (Augerprocess), the electronics in the valence band of protective layer is to the outermost layer migration of Ne.And, follow this electron transfer, other electronics in the protective layer has reception to above-mentioned Ne ⁺The energy changing of the electronics of migration and to discharge space 24 emission electromotive forces.As a result, because of having given play to secondary electron emission characteristic well, so discharge inception voltage Vf reduces.Because the emission of the electromotive force of the electronics of this protective layer is to firmly get the Ne of Duoing in the valence band upper end than protective layer ⁺Outermost electron energy level place carry out; so; even the electron emission characteristic of magnesium oxide crystalline solid 15A poor slightly (in other words, what have some impurity to sneak in the crystallization) also can obtain the sufficient secondary electron emission characteristic (γ) as the desired performance of protective layer.Therefore, for the oxide-film crystalline solid 15A of present embodiment 1,, also can obtain obvious effects even utilize employed magnesium oxide predecessor when in the working procedure of coating of thick film forming method, making protective layer.According to this thick film forming method, even the impurity that becomes to grade of the charcoal in residual some magnesium oxide predecessors in the protective layer also can form well behaved protective layer in present embodiment 1.Therefore, even the manufacturing process of protective layer self does not rely on the film forming method of the main equipment that need carry out vacuum treatment etc., the advantage that also can effectively utilize the thick film forming method with low-cost and high productive capacity realizes.

Have again, though from the electron transfer of the valence band of above-mentioned protective layer also can with Ne ⁺Outside the discharge gas composition between take place, still, Ne ⁺Be the most effective.This is because of enough low cause on the valence band of energy level with respect to protective layer of the outermost electron of Ne.

Secondly, the characteristic relevant with the inhibition of the discharge difference of protective layer 15 can be by bringing into play because of having the magnesium oxide crystal fine grain 15B that high-purity crystallized structure has a good electron emission characteristics.

Particularly, shown in the energy band diagram of the protective layer of Fig. 5, when PDP drives, when producing electric field in discharge space 24, utilize the vacuum ultraviolet of following (VUV), at first, the electronics among the magnesium oxide crystal fine grain 15B partly moves to oxygen defect.Then, utilize the energy difference (E2-E1) of the electronics of this oxygen defect part, as luminescence center, send visible light with the oxygen defect part.Follow the luminous of this visible light, in magnesium oxide crystal fine grain 15B, produce excitation electron near the energy level (impurity energy level E3) of the valence band Ev Ec of conduction band.By increasing the electronics of this impurity with reference to energy level E3, can improve the concentration of the charge carrier of protective layer 15, carry out impedance Control.As a result, the discharge difference in the time of can suppressing the PDP driving, the discharge probability of raising PDP prevents the generation of black noise simultaneously.The cause characteristic relevant with the inhibition of the discharge difference of protective layer 15 is and semiconductor carriers doping similar phenomena that protective layer 15 impurity are few, the good contour crystal property of directionality so require to have.Therefore, in present embodiment 1,, use the magnesium oxide crystal fine grain 15B of electron emission characteristic good (being above-mentioned high crystalline energy), it is shared be used for suppressing to discharge difference and the function that prevents black noise in order to obtain the inhibition effect of good discharge difference.In magnesium oxide crystal fine grain 15B,, use rich oxygen containing formation in order to obtain more oxygen defect part.

Like this; in present embodiment 1; at the surface portion of protective layer 15 towards discharge space 24; by making electron emission characteristic different a plurality of insulators (crystalline solid) 15A, 15B expose, share the function of flash-over characteristic by each crystalline solid 15A, 15B; to obtain to increase the control degrees of freedom of flash-over characteristic, enlarge the advantage of the degree of freedom of cell design or manufacture method simultaneously.

In addition, in the PDP1 of present embodiment 1,, also can obtain the preferable image performance by what reduce discharge inception voltage Vf, suppress the generation of discharge difference and prevent black noise even drive circuit does not use expensive high-voltage transistor.

Have again, be exposed to towards the insulator (crystalline solid) of the surface portion of the protective layer 15 of discharge space 24 and be not limited to magnesium oxide, can use in the insulator (for example MgAlO, BaO, CaO, ZnO, SrO etc.) in addition one or more.

And then; method as the protective layer 15 that forms present embodiment 1; be not limited to the magnesium oxide predecessor add the magnesium oxide crystal fine grain and to its apply, the method for roasting; also can adopt the method that fluent material is mixed with each other, the methods such as etching after can also taking to form pattern or forming pattern.

1-4, about situation to the protective layer impurity

Even the protective layer 15 of above-mentioned execution mode 1 adopts original formation also can obtain good effect, still,, can also further improve effect by taking following measure.

As an example, when according to 1E-17/cm ³Or above concentration is during at least to magnesium oxide crystal fine grain 15B doping Cr, when PDP drives, except that the oxygen defect part that just had originally, the luminescence center of the visible light of the about 700nm of wavelength is sent in formation, also increased near the electrons excited number conduction band in luminous enriching visible light, thus can improve more the effect that suppresses discharge difference (with reference to C.C.Chao, J.Phys.Chem.Solids, 32 2517 (1971) and M.Maghrabi et al, NIM B191 (2002) 181).

In addition, when according to 1E-16cm ³Or above concentration is when adding Si, H etc. to magnesium oxide crystal fine grain 15B at least, effect near the conduction band, excite accumulator (reservoir), can prolong the luminescent lifetime of luminescence center visible light, so, at this moment also can improve and suppress discharge difference and reduce the effect that black noise takes place.

As the method for at least magnesium oxide crystal fine grain 15B being added Si, can be after obtaining the basic comprising of above-mentioned 15A, 15B by roasting, make comprise silane or disilane gas be in the gaseous environment of plasmoid and handle, also can inject by doping Si atom or the molecule that contains Si.

As the method that protective layer is added H, can be at H ₂Gaseous environment in annealing in process is carried out on the protective layer surface, also protective layer can be placed on make and contain H ₂Gas be in the gaseous environment of plasmoid and handle.In addition, also can use the prior magnesium oxide crystal fine grain that has added H.

Below, the integral manufacturing method of PDP is described.

2, the manufacture method of PDP

The example of manufacture method of the PDP1 of execution mode 1 is described here.

In addition, this manufacture method also is applicable to the manufacture method of the PDP1 of other execution modes.

The making of 2-1, front panel

On the face of the front panel glass that the soda lime glass by the about 2.6mm of thickness forms, make show electrode.Here, the example that utilizes print process to form show electrode is shown, still, in addition, can also uses die coating process (die coating), scraper plate coating process (bladecoating) to form.

Pattern at first, according to the rules applies ITO (transparency electrode) material on the glass sheet in front.Make its drying again.

On the other hand, use the photomask method, metal (Ag) powder and organic carrier are mixed with light perception resin.Covering is coated on the above-mentioned transparent electrode material, and apparatus has the mask of the pattern that forms show electrode to cover.Then, expose from this mask top, development and roasting (sintering temperatures about 590～600 ℃).Thus, on transparency electrode, form bus.According to this photomask method, compare with existing silk screen print method of exceeding with 100 μ m live widths, can obtain live width carefully to the bus of 30 μ m.In addition, as the metal material of this bus, can also use in addition Pt, Au, Ag, Al, Ni, Cr or tin oxide, indium oxide etc.

In addition, except said method, can also utilize film forming electrode materials such as vacuum vapour deposition, sputtering method, carry out etch processes then and form above-mentioned electrode.

Secondly, on the show electrode that forms, the coating softening point is the dielectric glass powder of 550 ℃～600 ℃ lead oxide system or bismuth oxide system and the mixed lotion of organic bond that is formed by acetate of butyl carbitol (BUTYLCARBITOL ACETATE) etc.Then, under the temperature about 550 ℃～650 ℃, carry out roasting, form dielectric layer.

Secondly, utilize print process (thick film forming method) at the protective layer of the surface of dielectric layer formation as feature of the present invention.Specifically, the magnesium oxide crystal fine grain that is 50nm with preformed average grain diameter (space portion is emerging to produce) and mix as the magnesium oxide predecessor of the liquid organic material of the 2nd crystalline material (from diethoxy magnesium (magnesiumdiethoxide), magnesium naphthenate, magnesium caprylate, dimethoxy magnesium (magnesiumdimethoxide), select a kind or more than) as the 1st crystalline material.Utilize the said mixture of the thick about 1 μ m of coating on above-mentioned dielectric layer such as spin-coating method.As print process, in addition, also have die coating process, scraper plate coating process etc.After working procedure of coating is over,, fully remove the charcoal that comprises in the material impurity that becomes to grade, thus, form the protective layer of execution mode 1 at about 600 ℃ roasting temperature.As magnesian predecessor, also can use the material outside the above-mentioned material.

In addition, in above-mentioned example, used the magnesium oxide crystal fine grain that forms by a kind of material, but, also can suitably use multiple magnesium oxide crystal fine grain in order to reach the purposes of guaranteeing in the protective layer such as particle density.The size of magnesium oxide crystal fine grain can suitably determine that in the design of present protective layer (thickness is about 700nm～1 μ m), can use size is the particulates of tens nm to hundreds of nm according to the thickness of protective layer.

Even protective layer of the present invention has the advantage of utilizing the thick film forming method also can obtain good performance, still,, also can utilize the film forming method to form as long as in the scope that manufacturing cost and production capacity are allowed.At this moment, can use the common vacuum processing method of 2 kinds of different materials as evaporation source.

So far finish the making of front panel.

The making of 2-2, rear board

Utilize silk screen print method, on the surface of the rear board that the soda lime glass by thick about 2.6mm forms, being the strip coating by certain interval is the conductive material of main component with Ag, forms the address electrode of thick about 5 μ m.Here, for the PDP1 that makes making meets for example the NTSC specification or the VGA specification of 40 inches levels, the interval between adjacent 2 address electrodes is set in 0.4mm or following.

Then, applied thickness about 20 on whole of the rear board glass of calculated address electrode ^-The lead of 30 μ m is the glass lotion, carries out roasting again, forms dielectric film.

Secondly, using the lead identical with dielectric film is glass material, on dielectric film, between each neighbor address electrode, forms the barrier rib of high about 60～100 μ m.This barrier rib can carry out silk screen printing roasting formation then repeatedly by for example using the lotion that comprises above-mentioned glass material.Having, in the present invention, is the composition that includes Si in the glass material if constitute the lead of barrier rib again, then can improve the effect of the impedance rising that suppresses protective layer, and this is desirable just.This Si can be included in the chemical composition of glass, also can make an addition in the glass material.

After forming barrier rib, any the fluorescent ink that comprises redness (R) fluorophor, green (G) fluorophor or blueness (b) fluorophor in the wall of barrier rib and the surface applied that is exposed to the dielectric film between barrier rib, it is carried out drying and calcination process, form luminescent coating respectively.

The chemical composition of RGB fluorophor of all kinds is for example as follows.

Red-emitting phosphors: Y ₂O ₃: Eu ³⁺

Green-emitting phosphor: Zn ₂SiO ₄: Mn

Blue emitting phophor: BaMgAl ₁₀O ₁₇: Eu ²⁺

It is the material of 2.0 μ m that each fluorescent material can use average grain diameter.Ratio in 50 quality % puts it in the container (server), simultaneously, input is the ethyl cellulose (ethyl cellulose) of 1.0 quality % and is solvent (α-terpineol, the α-terpinenol) of 49 quality %, mix with sand mill, produce 15 * 10 ^-3The fluorescent ink of Pas.Then, utilize pump with its nozzle spraying and applying between barrier rib 20 from bore 60 μ m.At this moment, panel is moved along the long side direction of barrier rib 20, be strip coating fluorophor ink.Then, 500 ℃ roasting temperatures 10 minutes, form luminescent coating 21～23.

So far, finish the making of rear board.

Have, front panel glass and rear board glass all are to be formed by soda lime glass here again, but this is an example, also can be materials in addition.

2-3, PDP finish

Use the glass of sealing usefulness that front panel and the rear board made are fitted.Then, carry out exhaust, make the inner high vacuum (1.0 * 10 that forms of discharge space ^-4Pa), and to stipulate that fixed pressure (is that 66.5kPa～101kPa) encloses discharge gass such as Ne-Xe system, He-Ne-Xe system, He-Ne-Xe-Ar system therein here.In order to make protective layer of the present invention obtain the effect of electromotive force emission (secondary electron emission characteristic) effectively, can make to comprise Ne in the discharge gas.

So far, finish the making of PDP1.

3, execution mode 2

Below, use Fig. 4 that the formation of the PDP of execution mode 2 is described.

The formation of the protective layer 15 of shown present embodiment 2 is that carbon nanotube (CNT) 15C with the carbon crystalline solid is dispersed among the magnesium oxide crystalline solid 15A to replace above-mentioned magnesium oxide crystal fine grain 15B, makes it be exposed to discharge space 24.Utilize this magnesium oxide crystalline solid 15A and CNT15C to share the characteristic of the reduction discharge inception voltage Vf that protective layer 15 is required and the characteristic of inhibition discharge difference.This protective layer 15 for example can be by adding CNT to the organic material that comprises the magnesium oxide predecessor, and it is coated in carries out roasting on the front panel again and form.

If according to the PDP of such formation, when PDP drove, at first, magnesium oxide crystalline solid 15A played the effect identical with execution mode 1.CNT15C because of its electron emission characteristic well so and magnesium oxide crystalline solid 15A together, can improve the secondary electron yield (γ) of protective layer 15, reduce discharge inception voltage Vf well.

On the other hand, CNT15C has the effect of the electron emission amount that increases protective layer 15.Thus, when PDP drives, because of the carrier concentration raising of protective layer 15, thus can carry out impedance Control, thus discharge difference suppressed.The present invention also can be made of magnesium oxide and CNT like this.

Have again, here, show and use the formation of CNT, but in the present invention, use the fullerene good charcoal crystalline solid of electron emission characteristic such as (fullerene) in addition, also can obtain same effect as the charcoal crystalline solid.

4, other business

In above-mentioned execution mode 1,2; show the configuration example of PDP; but the invention is not restricted to this; for example; also be applicable to have the discharge space of enclosing discharge gas and, in above-mentioned discharge space, produce plasma and the Discharge illuminating element of luminous structure towards the protective layer of this discharge space configuration.Specifically, as the formation of Discharge illuminating element, for example, can be the structure of the single pixel unit of the PDP1 in the execution mode 1.

5, execution mode 3

The formation of 5-1, protective layer

Below, the PDP1 of the PDP fragmentary cross-sectional view explanation execution mode 3 of use Fig. 6.

Fig. 1 (a) is the profile of x direction, and Fig. 1 (b) is the y directional profile figure along a-a ' the line intercepting of Fig. 1 (a).The basic comprising of this PDP1 is identical with execution mode 1,2, has only the formation difference of the protective layer 15 of characteristic.

Promptly; in the PDP1 of execution mode 3; shown in Fig. 1 (a) and (b); at least at the surface portion of protective layer 15; in the substrate that forms by magnesium oxide, be provided as the island metal part 150 that the island metal material by having the Fermi level higher than above-mentioned magnesium oxide of the 2nd material forms towards discharge space 24 as the 1st material.Specifically, island metal part 150 be provided in a pair of show electrode 12,13 thickness directions (z direction) position overlapped at panel on (here under scan electrode 12).

To the island metal material, preferred work function is good at 5eV or following and anti-sputter, for example, and the preferred material of from Fe, Al, Mg, Ta, Mo, W, Ni, selecting.In above-mentioned example, use Al.

Have again,, can also select other various insulating material, semi-conducting material etc. and make it form island to use, to replace the island metal part as material with Fermi level higher than above-mentioned magnesium oxide.

The effect of 5-2, execution mode 3

Fig. 7 forms above-mentioned island metal part and to the photoelectron spectroscopy data of this mensuration on the MgO film.In Fig. 7, the data relevant with the protective layer of execution mode 3 are equivalent to 2A, and the data relevant with comparative example (by the film formed protective layer of common MgO) are equivalent to 2B.As the island metal part, be about 1/10 of unit peristome area.Island metal part of the present invention preferably set become to make its space periodic be cell size 1/10 or below.

By these data as can be known, in the data of 2A of the performance of expression execution mode 3, with the island metal part be that tiny area is irrelevant, the electronics emission is all in the 4.2eV place rising of the work function of Al.On the other hand, the rising of the electronics emission in the comparative example data then about 5.0eV, is equivalent to the energy of the Fermi level (energy) from vacuum standard to the MgO film of measuring.Therefore, in execution mode 3, can use the MgO film discharge inception voltage Vf that disinthibites itself, and utilize the island metal part to improve the electron emission characteristic of protective layer, the effect of the discharge difference that can be inhibited.

Fig. 8 illustrates being with of Al and MgO.From the energy relationship shown in this figure as can be known, in the protective layer 15 of execution mode 3,, can fully keep the wall electric charge by island metal part 150 being set on magnesian surface, and, the big characteristic of secondary amount can be obtained.This is the preferred characteristics of the protective layer of PDP.

Here, island metal part 150 must be designed to each other isolated state of insulation, if but the position of number, size, shape and formation can not make necessary wall electric charge such as cell discharge incur loss, just do not have problem.

In addition, the optimum seeking site that disposes above-mentioned island metal part 150 discharge of avoiding producing when driving because of PDP make sputter become significant protective layer surface the zone and also and can not cover the position that is used for the visible light that image shows.Because this reason, in present embodiment 3, as shown in Figure 6, this position be adapted at show electrode under, for example, under the bus on the scan electrode 12 12114.

In execution mode 3, experiment according to the present inventor, compared with prior art, can make discharge inception voltage Vf reduce about 20%, and, the hold facility of wall electric charge is compared with prior art not a halfpenny the worse, compared with prior art more is difficult to produce black noise, thereby can realize the PDP of function admirable.

6, execution mode 4

Below, the PDP1 of the front view explanation execution mode 4 of the protective layer of use Fig. 9.Fig. 9 (a) and Fig. 9 (b) illustrate other formation of protective layer respectively.

The basic comprising of this PDP1 is identical with execution mode 1～3, has only the formation difference of the protective layer 15 of characteristic.

In the configuration example shown in Fig. 9 (a); protective layer 15 is near the crystal boundary 153 of the magnesium oxide crystal fine grain 152 of adjacent conduct the 1st material or its; separate out have the Fermi level higher than the Fermi level of MgO insulator, semiconductor or metal as the 2nd material described in the execution mode 3, form complex with the whole protecting layer.

Such protective layer 15 can by make Mg etc. have about 650 ℃ or the metal material of following fusing point selectively in MgO fusion form.

Certainly, as the metal of separating out, preferably have 5eV or following work function and the good metal of anti-sputter, and be not limited to Mg at above-mentioned crystal boundary 153.Above-mentioned metal material also can be a kind or the above material of for example selecting from Fe, Al, Ta, Mo, W, Ni.

On the other hand, the configuration example shown in Fig. 9 (b) is by making insulator, semiconductor or metal (Fe) with Fermi level higher than the Fermi level of MgO wait the crystal fine grain 154 of other material to be dispersed in the protective layer 15 that nano composite material in the crystalline film forms that manys of MgO together with magnesium oxide crystal fine grain 152.As this nano composite material, for example, can use utilize Journalof the Ceramic Society of Japan 108 (9) (2000) p.781-784 in the nano composite material of MgO/Fe of disclosed fabrication techniques.

Metal as using at above-mentioned crystal fine grain 154 is not limited to Fe, and it is good to wish to have 5eV or following work function and anti-sputter.For example can use Mg, Al, Ta, Mo, W, Ni etc.

Figure 10 (a), 10 (b) illustrate the concrete formation of the protective layer 15 that the complex shown in Fig. 9 (a) and (b) or composite material are used for PDP.Figure 10 (a) is the profile of x direction, and Figure 10 (b) is the y directional profile figure along a-a ' the line intercepting of Figure 10 (a).In this formation shown in Figure 10, in each subpixel SU (discharge cell), the local protective layer zone that forms by above-mentioned complex or composite material that is provided with.Specifically; the protective layer zone that is formed by complex or composite material is the same with the island metal part 150 of above-mentioned execution mode 3, preferably is located at the discharge of avoiding producing when driving because of PDP and makes sputter become regional significantly and can not cover the luminous position of visible light that is used for the image demonstration.Because this reason, in the configuration example of Figure 10 (a) and (b), be island, partly be arranged on show electrode under, for example, be located at bus 121 on the scan electrode 12 under.

Have again, in execution mode 4, be not limited to local the constituting of the protective layer zone that forms by above-mentioned complex or composite material that be provided with, also can utilize above-mentioned complex or composite material to constitute whole protecting layer 15.

In execution mode 4, experiment according to the inventor, compared with prior art, can make discharge inception voltage Vf reduce about 20%, and, the hold facility of wall electric charge is compared with prior art not a halfpenny the worse, compared with prior art more is difficult to produce black noise, thereby can realize the PDP of function admirable.

The possibility of industrial utilization

The present invention is applicable to TV, but is specially adapted to the fine definition of fine definition reproduced image TV.

Claims (28)

1, a kind of plasma display, wherein, the 1st substrate that has formed protective layer through discharge space relative with the 2nd substrate dispose and described two substrates around sealed, it is characterized in that,

On the surface of protective layer, mutually different the 1st material of electron emission characteristic and the 2nd material are exposed to described discharge space respectively, and at least one side in the 1st material and the 2nd material disperses to exist.

2, as the plasma display of claim 1 record, it is characterized in that,

Described the 1st material is the 1st crystalline solid, and described the 2nd material is the 2nd crystalline solid,

On the surface of described protective layer, the 2nd crystalline solid is dispersed in the 1st crystalline solid.

3, as the plasma display of claim 2 record, it is characterized in that described the 2nd crystalline solid is than the purity height of described the 1st crystalline solid.

4, as the plasma display of claim 2 record, it is characterized in that,

Described protective layer is mainly formed by magnesium oxide,

Described the 2nd crystalline solid is formed by magnesian crystal fine grain.

5, as the plasma display of claim 4 record, it is characterized in that described the 1st crystalline solid obtains by the predecessor of roasting oxidation magnesium.

6, as the plasma display of claim 4 record, it is characterized in that described the 2nd crystalline solid is rich oxygen containing magnesium oxide.

7, as the plasma display of claim 2 record, it is characterized in that, in described protective layer, from silicon, hydrogen, chromium, select a kind or abovely at least the 2nd crystalline solid is mixed.

8, as the plasma display of claim 1 record, it is characterized in that, in described protective layer,, have magnesium oxide, exist as the 2nd material as the 1st material at least at surface portion towards described discharge space FullereneWith at least a kind of material in the carbon nanotube.

9, the plasma display of putting down in writing as claim 1; it is characterized in that; in described protective layer; at least at surface portion towards described discharge space; as described the 2nd material, there is the island metal material, has the insulating material of the Fermi level higher and has at least a kind of material in the semi-conducting material of the Fermi level higher than magnesium oxide than magnesium oxide.

As the plasma display of claim 9 record, it is characterized in that 10, described island metal material is made of the metal material with 5eV or following work function.

11, as the plasma display of claim 9 record, it is characterized in that described island metal material is made of the material of selecting from Fe, Al, Mg, Ta, Mo, W, Ni.

12, as the plasma display of claim 9 record, it is characterized in that,

On described the 1st substrate, between the surface of this substrate and protective layer, set how right a pair of show electrode;

Described island metal material is provided in for described a pair of show electrode on position overlapped on the thickness direction of protective layer.

13, as the plasma display of claim 1 record, it is characterized in that,

In described protective layer, at least at the magnesium oxide that exists towards the surface portion of described discharge space as the 1st material,

And, there is metal material, has the insulating material of the Fermi level higher and has at least a kind of material in the semi-conducting material of the Fermi level higher as the 2nd material than magnesium oxide than magnesium oxide.

14, as the plasma display of claim 13 record, it is characterized in that, have described the 2nd material at magnesian crystal boundary as described the 1st material.

As the plasma display of claim 13 record, it is characterized in that 15, described metal material is the metal material with 5eV or following work function.

16, as the plasma display of claim 13 record, it is characterized in that described metal material is made of the material of selecting from Fe, Al, Mg, Ta, Mo, W, Ni.

17, the plasma display of putting down in writing as claim 13; it is characterized in that described protective layer constitutes by containing magnesian the 1st material and comprising metal material, have the insulating material of the Fermi level higher than magnesium oxide and have the nano composite material that the 2nd dispersion of materials of a kind of material in the semi-conducting material of the Fermi level higher than magnesium oxide forms at least.

18, as the plasma display of claim 13 record, it is characterized in that,

In described plasma display, form a plurality of discharge cells dividing described discharge space,

Described the 2nd material part is present in the inside of described each discharge cell.

19, a kind of plasma display diaphragm forms with respect to the substrate surface of facing with discharge space, it is characterized in that,

In described diaphragm, towards the surface portion of described discharge space, there are mutually different the 1st crystalline solid of electron emission characteristic and the 2nd crystalline solid at least; Described the 2nd crystalline solid is dispersed in described the 1st crystalline solid.

20, a kind of plasma display diaphragm forms with respect to the substrate surface of facing with discharge space, it is characterized in that,

In described diaphragm, towards the surface portion of described discharge space, there is magnesium oxide and is dispersed in fullerene in this magnesium oxide and a kind or above material in the carbon nanotube at least.

21, a kind of Discharge illuminating element has the discharge space of enclosing discharge gas and the protective layer that disposes towards this discharge space, produces plasma and luminous in described discharge space, it is characterized in that,

In described protective layer, towards the surface portion of described discharge space, there are mutually different the 1st crystalline solid of electron emission characteristic and the 2nd crystalline solid at least, described the 2nd crystalline solid is dispersed in described the 1st crystalline solid.

22, a kind of Discharge illuminating element has the discharge space of enclosing discharge gas and the protective layer that disposes towards this discharge space, produces plasma and luminous in described discharge space, it is characterized in that,

In described protective layer,, there is magnesium oxide and is dispersed in fullerene in this magnesium oxide and a kind or above material in the carbon nanotube at least at surface portion towards described discharge space.

23, a kind of manufacture method of plasma display; comprise that the protective layer that forms protective layer with respect to the surface of the 1st substrate forms step and will form the surface of the 1st substrate of protective layer and the sealing step of the 2nd substrate sealing through discharge space; it is characterized in that

Described protective layer form step comprise the 2nd crystalline material is mixed into the 1st crystalline material after, again it is coated in the applying step and the calcination steps after described applying step on the surface of the 1st substrate.

24, as the manufacture method of the plasma display of claim 23 record, it is characterized in that, use the magnesium oxide predecessor, use the magnesium oxide crystal fine grain as the 2nd crystalline material as described the 1st crystalline material.

25, as the manufacture method of plasma displays of claim 23 or 24 records; it is characterized in that; form in the step at described protective layer, at least a kind or the above material that mixes and from silicon, hydrogen, chromium, select in the 2nd crystalline solid in the 1st crystalline solid and the 2nd crystalline solid.

26, as the manufacture method of the plasma display of claim 25 record; it is characterized in that; as forming at described protective layer in the step, from annealing in process and plasma doping, select any method to the method for the 2nd crystalline solid doped with hydrogen in the 1st crystalline solid and the 2nd crystalline solid at least.

27, as the manufacture method of the plasma display of claim 25 record; it is characterized in that; as the method that forms at described protective layer in the step doped silicon in the 2nd crystalline solid in the 1st crystalline solid and the 2nd crystalline solid at least, carry out silane or disilane plasma doping.

28, a kind of manufacture method of plasma display; comprise that the protective layer that forms protective layer with respect to the surface of the 1st substrate forms step and will form the surface of the 1st substrate of protective layer and the sealing step of the 2nd substrate sealing through discharge space; it is characterized in that

Described protective layer forms step and comprises at least a kind of material mixing in fullerene and the carbon nanotube after the magnesium oxide precursor material, it is coated in the applying step and the calcination steps after this applying step on the surface of the 1st substrate again.

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