JP3623406B2 - Gas discharge panel and manufacturing method thereof - Google Patents

Description

【００７０】
【表２】

【００７１】
【表３】

【００７２】
【表４】

【００７３】
５．実施例の性能評価
５─１．実施例Ｎｏ．１〜６（バイアス電圧を印加しつつプラズマＣＶＤ法で作製したＰＤＰ）と比較例Ｎｏ．１〜３との比較
表１に示されるように、実施例Ｎｏ．１〜３のＭｇＯ保護層ではソース物質の種類に関係なくカソードルミネッセンスに主として３５５ｎｍ、５７４ｎｍ、７００ｎｍ、９７５ｎｍの各発光ピークが確認された。表４の比較例Ｎｏ．１のＭｇＯ保護層と比較すると、これら４つのＰＤＰの保護層では７００ｎｍの発光ピークのみが一致している。このことは、実施例Ｎｏ．１〜３および比較例Ｎｏ．１のＭｇＯ保護層には１個の自由電子がトラップされたＦ中心が形成された一方、さらに実施例Ｎｏ．１〜３のＭｇＯ保護層には２個の自由電子がトラップされたＦ中心が形成されたことを示唆している（Ｐｈｙｓ．Ｒｅｖ．Ｂ．Ｖｏｌｕｍｅ．１ Ｎｏ．４、１５、Ｆｅｂ．１９７０を参照）。
【００７４】
また実施例Ｎｏ．４、５のＡｌ_２Ｏ_３保護層のカソードルミネッセンスを測定した結果、これらもソース物質に関係なく３００ｎｍと４１０ｎｍの発光ピークが同様に確認された。表４の比較例Ｎｏ．２のＡｌ_２Ｏ_３保護層と比較すると、これら３つのＰＤＰの保護層では３００ｎｍの発光ピークが一致しており、自由電子１個をトラップするＦ中心の存在を表すとともに、実施例Ｎｏ．４、５のＡｌ_２Ｏ_３保護層には２個の自由電子がトラップされたＦ中心が形成されていると思われる。
【００７５】
次に実施例Ｎｏ．６のＭｇＡｌ_２Ｏ_４保護層のカソードルミネッセンスを測定した結果には、３００ｎｍ、３５５ｎｍ、４１０ｎｍ、７００ｎｍの各発光ピークが見られ、比較例Ｎｏ．３のＭｇＡｌ_２Ｏ_４保護層では３００ｎｍの発光ピークが見られる。したがって実施例Ｎｏ．６および比較例Ｎｏ．３の両方に自由電子１個をトラップするＦ中心が形成されており、さらに実施例Ｎｏ．６には自由電子２個をトラップしたＦ中心が形成されたと思われる。
【００７６】
次に実施例Ｎｏ．１〜６と比較例Ｎｏ．１〜３のデータを全体的に比較すると、まずパネル輝度において、比較例Ｎｏ．１〜３（約４００ｃｄ／ｍ^２）に対して実施例Ｎｏ．１〜６（５００ｃｄ／ｍ^２）が１００ｃｄ／ｍ^２以上も向上している結果が測定された。次に放電開始電圧Ｖｆにおいては、比較例Ｎｏ．１〜３（２５０Ｖ前後）に対し実施例Ｎｏ．１〜６（１６５〜１８５Ｖ）が最大８０Ｖ以上も低減されており、放電維持電圧Ｖｍに至っては比較例Ｎｏ．１〜３（１９０〜２００Ｖ程度）に対し実施例Ｎｏ．１〜６（９８〜１１８Ｖ）が１００Ｖ程度まで低減されているものも見られる。
【００７７】
このような比較例Ｎｏ．１〜３に対する実施例Ｎｏ．１〜６の測定結果は、２個の自由電子をトラップしたＦ中心を保護層に形成したことにより、従来よりも二次電子が豊富に得られるようになり、放電空間におけるプラズマの規模が二次電子によって低電力でも良好に拡大できたため、パネル輝度および放電に係る電力効率の両面において非常に優れた性能が発揮されたものと考えられる。
【００７８】
なお当該表１のデータから、実際にバイアス電圧を利用したプラズマＣＶＤ法でＰＤＰを作製するときは、３０〜３００Ｐａ程度の圧力下で、かつフロントパネルに─１００〜─２００Ｖ程度の負のバイアス電圧を印加するのが望ましいと言える。
５─２．実施例Ｎｏ．７〜１３（バイアス電圧を印加しつつスパッタ法で作製したＰＤＰ）と比較例Ｎｏ．１〜３との比較
表２に示すように、実施例Ｎｏ．７、８、１１および比較例Ｎｏ．１のＭｇＯ保護層のカソードルミネッセンスを測定した結果、前記実施例Ｎｏ．１〜６と同じ発光ピークが確認された。したがって実施例Ｎｏ．１〜６等と同様の考察により、実施例Ｎｏ．７、８および比較例Ｎｏ．１のＭｇＯ保護層はともに１個の自由電子をトラップするＦ中心を有し、実施例Ｎｏ．７、８では２個の電子がトラップされたＦ中心が形成されたと思われる。
【００７９】
また実施例Ｎｏ．９、１２のＡｌ_２Ｏ_３保護層には３００ｎｍと４１０ｎｍの各発光ピークが確認された。これらのうち４１０ｎｍの発光ピークは実施例Ｎｏ．４、５と同様に２個の自由電子がトラップされたＦ中心を示すものと思われる。
さらに実施例Ｎｏ．１０と比較例Ｎｏ．３のＭｇＡｌ_２Ｏ_４保護層を比較すると、両者に見られる３００ｎｍの発光ピークは１個の自由電子をトラップしたＦ中心、それ以外の発光ピークを持つ実施例Ｎｏ．１０には２個の自由電子をトラップするＦ中心が形成されていることをそれぞれ表しているのが分かる。
【００８０】
なおＮｏ．１３の保護層はＭｇＯとＡｌ_２Ｏ_３の積層構造となっているため、ＭｇＯとＡｌ_２Ｏ_３の両方のピークが得られたものと思われる。
次に実施例Ｎｏ．７〜１３と比較例Ｎｏ．１〜３のデータを全体的に比較すると、パネル輝度において、実施例Ｎｏ．１〜６と同様に、比較例Ｎｏ．１〜３（約４００ｃｄ／ｍ^２）に対し実施例Ｎｏ．７〜１３（５０５ｃｄ／ｍ^２以上）が１００ｃｄ／ｍ^２以上も向上している結果が測定された。次に放電開始電圧Ｖｆにおいて、比較例Ｎｏ．１〜３（２５０Ｖ前後）に対し実施例Ｎｏ．７〜１３（１８５〜１９５Ｖ前後）と６０Ｖ程度の電圧の低減効果が見られた。さらに放電維持電圧Ｖｍでも比較例Ｎｏ．１〜３（１９０〜２００Ｖ程度）に対し実施例Ｎｏ．７〜１３（１２０Ｖ前後）が１００Ｖ程度まで低減されている。
【００８１】
比較例Ｎｏ．１〜３に対する実施例Ｎｏ．７〜１３の測定結果も、２個の自由電子をトラップしたＦ中心により、従来よりも二次電子が豊富に得られ、プラズマが二次電子によって低電力でも良好に拡大できた結果、パネル輝度および電力効率などにおいて優れた性能が発揮されたことを表している。
なお当該表２のデータから、実際にバイアス電圧を利用したスパッタ法でＰＤＰを作製するときは、０．１〜１０Ｐａ程度の圧力下で、かつフロントパネルに─１００〜─２００Ｖ程度の負のバイアス電圧を印加するのが望ましいと言える。
【００８２】
５─３．実施例Ｎｏ．１４〜２０（バイアス電圧を印加しつつイオンプレーティング法で作製したＰＤＰ）と比較例Ｎｏ．１〜３との比較
表３に示すように、実施例Ｎｏ．１４〜２０のＰＤＰについて保護層のカソードルミネッセンスを測定した結果、Ｎｏ．１４、１５、１９のＭｇＯ保護層、実施例Ｎｏ．１６、１７、２０のＡｌ_２Ｏ_３保護層、実施例Ｎｏ．１８のＭｇＡｌ_２Ｏ_４保護層のそれぞれについて、表１および表２、表４と同様の各発光ピークが確認された。すなわちこれら実施例Ｎｏ．１４〜２０の保護層には、１個および２個の自由電子をそれぞれトラップするＦ中心が形成されていることが示された。
【００８３】
次に実施例Ｎｏ．１４〜２０と比較例Ｎｏ．１〜３のデータを全体的に比較すると、パネル輝度において、実施例Ｎｏ．１〜１３とほぼ同様に、比較例Ｎｏ．１〜３（約４００ｃｄ／ｍ^２）に対し実施例Ｎｏ．４〜２０（５０５ｃｄ／ｍ^２以上）が１００ｃｄ／ｍ^２以上も向上している結果が測定された。特に実施例Ｎｏ．２０、１６、２５の各Ａｌ_２Ｏ_３保護層においては、それぞれ５３０ｃｄ／ｍ^２、５４０ｃｄ／ｍ^２、５２５ｃｄ／ｍ^２と比較的高いパネル輝度を発揮した。
【００８４】
また放電開始電圧Ｖｆにおいては、比較例Ｎｏ．１〜３（２５０Ｖ前後）に対し実施例Ｎｏ．１４〜２０（１６０〜１７５Ｖ前後）と７５Ｖ程度まで低電圧を実現できる効果が見られた。さらに放電維持電圧Ｖｍでは、比較例Ｎｏ．１〜３（１９０〜２００Ｖ程度）に対し実施例Ｎｏ．１４〜２０（１０５Ｖ前後）が１００Ｖ程度まで低減されている。これらＶｍ、Ｖｆに関しては、実施例Ｎｏ．２０が最もバランスよく優れるといった結果が得られた（Ｖｆ＝１６０Ｖ、Ｖｍ＝１００Ｖ）。
【００８５】
このように実施例Ｎｏ．２０がパネル輝度、電力効率ともに優れているのは、二次電子の放出量が多いためと思われる。
比較例Ｎｏ．１〜３に対する実施例Ｎｏ．１４〜２０の測定結果も、２個の自由電子をトラップしたＦ中心により、従来よりも二次電子が豊富に得られ、プラズマが二次電子によって低電力でも良好に拡大され、パネル輝度および電力効率などにおいて優れた性能が発揮されたことを表していると思われる。
【００８６】
なお当該表３のデータから、実際にバイアス電圧を利用したイオンプレーティング法でＰＤＰを作製するときは、０．０１〜１．０Ｐａ程度の圧力下で、かつフロントパネルに─１００〜─２００Ｖ程度の負のバイアス電圧を印加するのが望ましいと言える。
６．その他の事項
上記実施の形態および実施例ではハイビジョン型ＰＤＰを作製する例について示したが、当然ながら本発明はこれに限定するものではなく、別の規格のＰＤＰやガス放電パネルに適用してもよい。
【００８７】
さらに、放電ガスはＮｅ─Ｘｅ系に限らず、これ以外の放電ガスであってもよい。
また、上記実施の形態および実施例では保護層に負のバイアス電圧を印加する例を示したが、本発明はこれに限定せず、プラズマＣＶＤ装置、スパッタ装置、イオンプレーティング装置等の高周波発生部とフロントパネルとの間に上記負のバイアス電圧に相当する電圧差を設けることができればよい。
【００８８】
また、本発明ではプラズマＣＶＤ装置、スパッタ装置、イオンプレーティング装置のいずれかを組み合わせてもよく、これによって例えば異なる材料を積層して保護層を形成するようにしてもよい。
さらに、本発明の保護層を構成する金属酸化物として酸化マグネシウムＭｇＯ、酸化アルミニウムＡｌ_２Ｏ_３、スピネルＭｇＡｌ_２Ｏ_４を挙げたが、これらのいずれかを組み合わせて保護層を形成してもよいし、これ以外の材料で保護層を構成しても構わない。
【００８９】
さらに、上記実施の形態および実施例は誘電体層本体に保護層を積層し、これを誘電体層とする例を示したが、誘電体層本体を上記金属酸化物から構成し、保護層を省略する構成としてもよい。
さらに、２個の自由電子がトラップされたＦ中心を形成し易くする方法の一つとして、プラズマＣＶＤ装置、スパッタ装置、イオンプレーティング装置等の内部の雰囲気中におけるＯ_２濃度を低くしたり、Ｈ_２等の還元性ガスを添加すると効果的に上記Ｆ中心が形成されることが別の実験により明らかになっている。本発明ではこのような方法を併用することによってＦ中心を形成するようにしてもよい。
【００９０】
【発明の効果】
以上のことから明らかなように、本発明は第一の電極と誘電体層が表面にその順に形成された第一のプレートと、第二のプレートが、前記誘電体層と対向するように配設されたガス放電パネルであって、前記誘電体層は、少なくとも第二のプレートに対向する表面が金属酸化物より構成され、かつ当該金属酸化物の結晶構造中には２個の自由電子がトラップされた酸素欠陥が含まれているので、消費電力を上昇させることなく前記２個の自由電子により放電規模が良好に拡大され、パネル輝度が向上する。また当該自由電子により放電中の電子数が豊富になるので、放電遅れが改善され、走査速度の向上が期待できる。したがって従来より低い駆動電圧で駆動でき、かつ良好な発光効率が得られるので、優れたハイビジョン型ＰＤＰなどのガス放電パネルを実現が可能となる。
【００９１】
このような本発明のガス放電パネルは、第一の電極を形成した第一のプレート表面に誘電体層を形成する第一ステップと、第一のプレート面と第二のプレート面を対向して貼着する第二ステップとを備えるガス放電パネルの製造方法によって、前記第一ステップにおいて、プラズマＣＶＤ装置、スパッタ装置、イオンプレーティング装置から選択した装置を用い、当該装置の高周波発生部と第一のプレートとの間にバイアス電圧を印加しつつ、少なくとも第二のプレートに対向する表面部分が金属酸化物からなる誘電体層を形成することにより製造が可能である。
【図面の簡単な説明】
【図１】本発明の一適用例である交流面放電型ＰＤＰの部分的な断面斜視図である。
【図２】ＰＤＰの厚み方向の部分断面図である。
【図３】プラズマＣＶＤ装置の概略図である。
【図４】スパッタ装置の概略図である。
【図５】イオンプレーティング装置の概略図である。
【符号の説明】
２０ フロントパネル
２１ フロントパネルガラス
２２、２３ 表示電極
２４ 誘電体層
２６ バックパネル
２８ アドレス電極
３８ 放電空間
４０ プラズマＣＶＤ装置
４１ａ、４１ｂ、６１ａ Ａｒガスボンベ
４２、４３ 気化器
４２Ｌ、４３Ｌ 液体ソース物質（金属キレートおよびシクロペンタジエニル化合物）
４２Ｈ、４３Ｈ ヒータ
４４、６１ｂ Ｏ２ガスボンベ
４５ プラズマＣＶＤ装置本体
４６、６３、８１ プレート加熱ヒータ
４７、６４ 高周波発生装置
４８、６７、８８ 高周波電源
４９、６６、８３ 減圧ポンプ
５０、６４、８６ バイアス電源
６０ スパッタ装置
６２ ターゲット材（固体ソース物質）
６５ スパッタ装置本体
８０ イオンプレーティング装置
８２、４７２、６４２ 加熱テーブル
８４ ホローカソード蒸発源
８５ プラズマ発生コイル
８９ 電源
２４１ 誘電体層本体
２４２ 保護層
４７１、６４１ 高周波発生部
Ｃ１〜Ｃ７ バルブ
Ｌ１〜Ｌ１２ 配管[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas discharge panel used for a display device or the like and a manufacturing method thereof, and more particularly, to a high-quality plasma display panel and a manufacturing method thereof.
[0002]
[Prior art]
In recent years, expectations for high-definition and large-screen displays such as high-definition have been increasing, and research has been conducted on various display devices such as CRT, liquid crystal display (LCD), and plasma display panel (PDP) in order to meet their expectations. Has been developed.
[0003]
CRTs that have been widely used as television displays have been excellent in terms of resolution and image quality, but they tend to increase in depth and weight as they become larger, and are not suitable for larger screens of 40 inches or more. is there. LCD has low power consumption and has the advantage of avoiding problems with depth and weight, but has problems that should be improved in terms of process cost and response speed for display when the screen is actually enlarged. .
[0004]
Compared to such a CRT or LCD, a PDP used in a gas discharge display device is relatively easy to enlarge on a small screen. A PDP has a plurality of pairs of barrier ribs (ribs) formed between two glass plates in a stripe shape and phosphor layers arranged for each color of RGB between the barrier ribs and arranged perpendicular to the longitudinal direction of the barrier ribs. The display electrode discharges in a discharge gas (He-Xe system, Ne-Xe system, etc.) sealed in the discharge space between the barrier ribs and the glass plate, and the phosphor is excited and emitted by ultraviolet rays (UV) generated thereby. To display.
[0005]
As for the PDP having such a structure, a 50-inch class product has already been developed.
[0006]
[Problems to be solved by the invention]
The panel luminance of the PDP mainly depends on the intensity of ultraviolet rays generated in the discharge gas. Current 40-42 inch class (640 x 480 pixels, cell pitch 0.43 mm x 1.29 mm, unit cell area 0.55 mm²) NTSC PDP of 150 to 250 cd / m depending on ultraviolet rays (wavelength of about 147 nm)²The luminous efficiency is obtained.
[0007]
On the other hand, a high-definition type PDP that has attracted attention in recent years is, for example, a 42-inch class with a pixel number of 1920 × 1125, a cell pitch of 0.15 mm × 0.48 mm, and a unit cell area of 0.072 mm.²Such a performance is required, and the structure is considerably higher than that of current PDP products. In general, the intensity of ultraviolet rays is proportional to the volume of the discharge space, and the light emission efficiency also depends on the ultraviolet light receiving area of the phosphor layer. Therefore, in a high-definition PDP, the discharge space is small and the light emission efficiency tends to decrease. Therefore, when a high-definition type PDP is manufactured by the conventional technology, the luminous efficiency is 30 to 40 cd / m.²It seems that it will go down to. In order to perform good screen display with a high-definition PDP, it is necessary to dramatically improve the light emission efficiency.
[0008]
In a high-definition panel, the gap between each pair of display electrodes is narrower than before. In this case, under a general discharge gas sealing pressure (500 to 760 Torr), the discharge start voltage at each pair of display electrodes is higher than in the past (Paschen's law). In a high-definition PDP, the number of unit cells is large, and the number of display electrodes is proportional to this. Therefore, it is expected that the overall power consumption of the PDP will increase considerably. In the present day when products with low power consumption are desired, it is necessary to suppress such an increase in power consumption.
[0009]
In addition, the number of scanning lines in a high-definition PDP increases approximately three times as compared with the prior art. This means that a scanning speed about three times that of the prior art is required to display a high-resolution screen such as a high-vision type PDP. Here, there is a property that a slight time delay (discharge delay) occurs between the application of a pulse to each pair of display electrodes and the actual discharge. For this reason, in order to display a high-resolution screen with a high-definition PDP, it is necessary to improve the scanning speed by keeping the discharge delay short.
[0010]
As described above, the present invention has been made mainly in view of the three problems of improvement of panel luminance, suppression of power consumption, and improvement of scanning speed, and the object thereof can be driven with a lower driving voltage than in the prior art. And it is providing the gas discharge panel excellent in luminous efficiency, and its manufacturing method.
[0011]
[Means for solving the problems]
In order to solve the above-described problem, the present invention provides a first plate having a first electrode and a dielectric layer formed on a surface thereof in that order, and a second plate disposed so as to face the dielectric layer. As the gas discharge panel, the dielectric layer has at least a surface facing the second plate made of a metal oxide, and oxygen in which two free electrons are trapped in the crystal structure of the metal oxide. Defects are assumed to be included.
[0012]
By the dielectric layer having such a configuration, primary electrons generated due to ionization of the discharge gas at the start of discharge are at least a layer made of a metal oxide on the surface of the dielectric layer (hereinafter also referred to as embodiments and examples). Collision with oxygen defects in the protective layer), and two free electrons are emitted as secondary electrons into the discharge space. In the present invention, since oxygen defects that trap two free electrons are present in the protective layer, there are more secondary electrons than the conventional protective layer that mainly has only oxygen defects that trap one free electron. can get.
[0013]
Therefore, in the present invention, even when the same voltage is applied, a relatively abundant number of electrons are present in the discharge space, a plasma of a good scale is formed with low power, and a gas discharge panel with excellent luminous efficiency is obtained. It can be realized. In addition, the presence of abundant secondary electrons makes it easy to quickly form a discharge even when a low voltage is applied, so an effect of improving the scanning speed can be expected.
[0014]
For this reason, the present invention is particularly effective for a gas discharge panel such as a high-vision type PDP.
As the metal oxide, magnesium oxide (MgO), aluminum oxide (Al₂O₃), Spinel (MgAl₂O₄) And the like.
Such a gas discharge panel of the present invention includes a first step of forming a dielectric layer on the surface of the first plate on which the first electrode is formed, and the first plate surface and the second plate surface facing each other. A gas discharge panel manufacturing method comprising a second step of attaching, in the first step, using a device selected from a plasma CVD device, a sputtering device, and an ion plating device, It is possible to manufacture by forming a dielectric layer made of a metal oxide at least on the surface portion facing the second plate while applying a bias voltage to the other plate.
[0015]
Specifically, as will be described in the examples described later, it has become clear that it is desirable to manufacture under the following conditions.
That is, when a plasma CVD apparatus is used, in the first step, a layer made of the metal oxide is applied while applying a negative bias voltage of −100 V to −200 V to the first plate under a pressure of 30 Pa to 300 Pa. It is desirable to form.
[0016]
When a sputtering apparatus is used, in the first step, the negative electrode is applied with a negative bias voltage of −100 V to −200 V to the first plate under a pressure of 0.1 Pa to 10 Pa. It is desirable to form a layer.
Further, when using an ion plating apparatus, in the first step, a negative bias voltage of −500 V to −1500 V is applied to the first plate under a pressure condition of 0.01 Pa to 1.0 Pa, It is desirable to form a layer made of the metal oxide.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
1. Configuration of gas discharge panel (PDP)
1-1. Overall structure of PDP
FIG. 1 is a partial sectional perspective view showing a main configuration of a PDP AC surface discharge type PDP (hereinafter simply referred to as “PDP”) which is an example of a gas discharge panel according to an embodiment of the present invention. In the drawing, the z direction corresponds to the thickness direction of the PDP, and the xy plane corresponds to a plane parallel to the panel surface of the PDP. This PDP is configured to meet the high-vision specifications of the 42 inch class.
[0018]
As shown in FIG. 1, the PDP includes a front panel 20 and a back panel 26 that are disposed with their main surfaces facing each other.
A front panel glass 21 which is a substrate of the front panel 20 is formed by a strip-shaped transparent electrode 220 (230) having a thickness of 0.1 μm and a width of 150 μm on one side and a bus line 221 (231) having a thickness of 7 μm and a width of 50 μm. A plurality of pairs of display electrodes 22 (23) (X electrodes 23, Y electrodes 22) that are configured are arranged in parallel along the x direction, and surface discharge is performed in a gap (about 50 μm) between each pair of display electrodes 22, 23. It is like that.
[0019]
The front panel glass 21 provided with the display electrodes 22 and 23 is coated with a dielectric layer 24 over the entire surface of the glass 21. Specifically, the dielectric layer 24 includes a dielectric layer main body 241 and a protective layer 242, and the surface of the front panel glass 21 is coated with a dielectric layer 241 main body having a thickness of about 20 μm and a thickness of about 0.2 mm. A 9 μm protective layer 242 is coated.
[0020]
A plurality of address electrodes 28 having a thickness of 5 μm and a width of 60 μm are arranged on one side of the back panel glass 27 serving as a substrate of the back panel 26 in a stripe pattern at regular intervals (about 150 μm) with the y direction as the longitudinal direction. A dielectric film 29 having a thickness of 30 μm is coated over the entire surface of the back panel glass 27 so as to enclose the address electrodes 28. On the dielectric film 29, a partition wall 30 having a height of 100 μm and a width of 35 μm is disposed in accordance with the gap between the adjacent address electrodes 28, and on the side surface of the adjacent partition wall 30 and the surface of the dielectric film 29 therebetween. The phosphor layers 31 to 33 corresponding to any one of red (R), green (G), and blue (B) are formed. These RGB phosphor layers 31 to 33 are sequentially arranged in the x direction.
[0021]
The front panel 20 and the back panel 26 having such a configuration are bonded at the outer peripheral edge portions of both the panels 20 and 26 while facing the address electrodes 28 and the display electrodes 22 and 23 so that the longitudinal directions thereof are orthogonal to each other. And sealed. A discharge gas (filled gas) made of a rare gas component such as He, Xe, or Ne is sealed between the panels 20 and 26 at a predetermined pressure (usually about 500 to 760 Torr in the past).
[0022]
A discharge space 38 is formed between adjacent barrier ribs 30, and a region where a pair of adjacent display electrodes 22, 23 and one address electrode 28 intersect with each other across the discharge space 38 corresponds to a cell (not shown) for image display. doing. The cell pitch in the x direction is about 160 μm, and the cell pitch in the y direction is about 480 μm.
When the PDP is driven, a panel driving unit (not shown) selects either the address electrode 28 or the display electrodes 22 and 23 (in the present embodiment, this is the X electrode 23. In general, the X electrode 23 is A scan electrode and a Y electrode 22 are called sustain electrodes), and a pulse is applied to the pair of display electrodes 22 and 23 after a write discharge (address discharge) is performed on each cell by discharging. Then, by discharging, a short wavelength ultraviolet ray (resonance line having a wavelength of about 147 nm as a central wavelength) is generated, and the phosphor layers 31 to 33 are caused to emit light to display an image.
[0023]
Here, the main feature of the present PDP is the configuration of the protective layer 242. The protective layer 242 is characterized in that an oxygen defect (F center) trapping two free electrons exists in the crystal structure.
1-2. Effects of the configuration of the protective layer of the present embodiment
According to the PDP having the protective layer having the above-described configuration, when a pulse is applied to each pair of display electrodes 22 and 23 in the initial stage of the discharge sustaining period when the PDP is driven, the gap between the display electrodes 22 and 23 is reduced. The discharge starts. Then, the discharge gradually expands from the surface of the protective layer 242 to the discharge space, and the atoms of the discharge gas are ionized to form plasma. At this time, primary electrons are generated from the ionization of the discharge gas and collide with the surface of the protective layer 242, but when the primary electrons collide with the F center where two free electrons are trapped, both of these free electrons are secondary. It jumps out into the discharge space 38 as electrons.
[0024]
FIG. 2 is a cross-sectional view in the z direction of the front panel 20 with the protective layer 242 at the center. As shown in the figure, in the present embodiment, when the primary electrons collide with the F center of the protective layer 242, secondary electrons that are multiples of the primary electrons are theoretically obtained. In this figure, in order to make this mechanism easy to understand, only primary electrons that collide with the F center are shown, but of course the primary electrons actually exist on the surface of the protective layer 242 in other regions (existing from the past). And the phosphor layers 31 to 33 collide with each other.
[0025]
Here, when the secondary electron emission coefficient is γ and the discharge start voltage is Vf, these relations can be expressed by the following formula 1 (see “Plasma Display”, Kyoritsu Shuppan 1983, pp. 43).
[Expression 1] Vf = E / αln (1 / γ + 1)
E and α are both constants determined by the type of discharge gas.
[0026]
As shown in Equation 1, since the discharge start voltage Vf and the secondary electron emission coefficient γ are in an inversely proportional relationship, the secondary layer emission amount is improved by the protective layer 242 of the present invention, which has improved the amount of secondary electrons emitted conventionally. Since the secondary electron emission coefficient γ takes a large value, the discharge start voltage Vf is reduced.
As a result, the plasma is expanded by abundant secondary electrons, good fluorescence is obtained, and the panel brightness is improved. In addition, since the number of electrons in the plasma becomes abundant, the voltage (writing voltage) at the time of address discharge is also suppressed, and the power consumption for driving the PDP as a whole is efficiently reduced.
[0027]
In addition, the write voltage is suppressed in the state where there are abundant secondary electrons in the discharge space 38, and address discharge can be performed at a lower voltage than before, and the discharge is performed after applying a pulse to each electrode 22, 23, 28. Time (discharge delay) is shortened (see “Plasma Display”, Kyoritsu Shuppan, pp. 50-51, 1982). Accordingly, the responsiveness of the screen display is improved, and it is possible to obtain a good display performance (scanning speed) even in a gas discharge panel having a relatively large number of scanning lines such as a high-vision type PDP.
[0028]
In addition to MgO, Al₂O₃, MgAl₂O₄The F center that traps two secondary electrons in the crystal structure can be formed with a material such as (refer to “Materials of Electrical Discharge Study Group” ED-98-202 1998). Therefore, in the present invention, these materials are also protected. It can be used as a material for the layer 242.
With the above-described configuration of the protective layer 242, the present PDP can obtain good panel luminance and excellent luminous efficiency. The reason can be specifically considered as follows.
[0029]
1-3. About the difference in the protective layer between the conventional and this embodiment
As described above, in the PDP, a plasma of a discharge gas is formed in the discharge space based on the discharge generated from each pair of display electrodes 22 and 23, and ultraviolet rays are generated by this plasma to excite and emit phosphors. The light emission scale (panel luminance) of the body is proportional to the intensity of ultraviolet rays. This means that the panel brightness is improved when the number of electrons contained in the plasma is increased to increase the intensity of ultraviolet rays.
[0030]
The primary electrons derived from the discharge of each pair of display electrodes 22, 23 and contained in the plasma are discharged from one display electrode 22 (23) of the pair of display electrodes 22, 23 through the surface of the protective layer 242. After spreading to 38, it moves again to the other display electrode 23 (22).
Here, a portion called an oxygen defect (F center) that traps free electrons exists in the crystal structure of the protective layer 242 heretofore. When primary electrons collide with the center of F, free electrons trapped in oxygen defects jump out into the discharge space 38 and become secondary electrons. Since the plasma in the discharge space 38 is also formed by secondary electrons, the discharge scale is increased as the discharge space 38 is filled with secondary electrons. In other words, the larger the number of secondary electrons in the discharge space 38, the larger the plasma and the higher the panel brightness. Therefore, the larger the number of secondary electrons obtained for the primary electrons, the better ("Plasma Display" Kyoritsu Publishing Co., Ltd.) ) Pp. 47-49, 1982).
[0031]
Here, the F center existing in the conventional protective layer is a kind that traps only one free electron (see Y. CHEN, Phys. Rev. Volume. 182 No. 3 pp. 182, 1969). Even if one primary electron hits the F center, only one secondary electron was obtained. Therefore, it is difficult to efficiently acquire secondary electrons and effectively utilize the plasma to expand the panel brightness.
[0032]
In contrast, in the present invention, an F center in which two free electrons are trapped is formed in the crystal structure of the protective layer 242, and two secondary electrons are theoretically obtained by collision of one primary electron. In this way, sufficient secondary electrons are obtained to improve the panel brightness.
1-4. Method for confirming existence of oxygen defect (F center) in protective layer
The F center in which two free electrons are trapped exhibits a unique emission peak in the cathodoluminescence measurement, so that the presence can be confirmed. Specifically, in the case of MgO, it exhibits respective emission peaks of wavelengths 355, 574, and 975 nm, and Al₂O₃In the case of, the emission peak at 410 nm, and further MgAl₂O₄In the case of, each emission peak of 355, 410, and 700 nm is exhibited. Conventionally, the emission peak of cathodoluminescence at the F center that traps one free electron existing in the protective layer is 700 nm for MgO, Al₂O₃300nm, MgAl₂O₄Is known to be 300 nm (for details, see Al₂O₃For the Meteorological Society of Japan, ED98-202, pp. 23, 1998, for MgO, see Phys. Rev. B. Volume. 1 No. 4, 15, Feb. See 1970 etc., MgAl₂O₄About Al₂O₃And analogy).
2. Manufacturing method of PDP
Next, an example of the method for manufacturing the PDP will be described.
[0033]
2-1. Front panel fabrication
Display electrodes 22 and 23 are formed on the surface of a front panel glass 21 made of soda-lime glass having a thickness of about 2.6 mm. For this, first, the transparent electrodes 220 and 230 are formed by the following photoetching.
A photoresist (for example, an ultraviolet curable resin) is applied to the entire surface of the front panel glass 21 with a thickness of about 0.5 μm. Then, a photomask having a pattern of the transparent electrodes 220 and 230 is superimposed thereon, irradiated with ultraviolet rays, and immersed in a developer to wash out uncured resin. Next, ITO or the like is applied to the resist gap of the front panel glass 21 as a material for the transparent electrodes 220 and 230. Thereafter, the resist is removed with a cleaning solution or the like to complete the transparent electrodes 220 and 230.
[0034]
Subsequently, bus lines 221 and 231 having a thickness of about 7 μm and a width of 50 μm are formed on the transparent electrodes 220 and 230 using a metal material mainly composed of Ag or Cr—Cu—Cr. When Ag is used, a screen printing method can be applied, and when Cr—Cu—Cr is used, a vapor deposition method or a sputtering method can be applied.
Thus, the display electrodes 22 and 23 are formed.
[0035]
Next, lead oxide (PbO), boron oxide (B₂O₃), An organic binder (a solution of 10% ethyl cellulose in α-terpineol) mixed in a weight ratio of 75:15:10 is coated over the entire surface of the front panel glass 21 and fired. (At 520 ° C. for 10 minutes) to form a dielectric layer body 241 having a thickness of about 20 μm.
[0036]
Next, on the surface of the dielectric layer body 241, magnesium oxide (MgO), aluminum oxide (Al₂O₃), Spinel (MgAl₂O₄), And a protective layer 242 having a thickness of about 0.9 μm and having an F center in which two electrons are trapped in the crystal is formed. A specific method for forming the protective layer 242 will be described later.
Thus, the front panel 20 is manufactured.
[0037]
2-2. Back panel fabrication
On the surface of the back panel glass made of soda lime glass 27 having a thickness of about 2.6 mm, a conductive material mainly composed of silver (Ag) is applied in stripes at regular intervals by a screen printing method. An address electrode 28 of 5 μm is formed.
Subsequently, a lead-based glass paste is applied over the entire surface of the back panel glass 27 on which the address electrodes 28 are formed to a thickness of about 20 to 30 μm and baked to form a dielectric film 29.
[0038]
Next, a partition 30 having a height of about 120 μm is formed on the dielectric film 29 for each gap (about 150 μm) between adjacent address electrodes 28 using the same lead-based glass material as the dielectric film 29. The partition wall 30 can be formed, for example, by repeatedly screen-printing a paste containing the glass material and then firing it.
Once the barrier ribs 30 are formed, red (R) phosphor, green (G) phosphor, and blue (B) fluorescence are formed on the wall surfaces of the barrier ribs 30 and the surface of the dielectric film 29 exposed between the adjacent barrier ribs 30. A fluorescent ink containing any one of the bodies is applied and dried and fired to form phosphor layers 31 to 33, respectively.
[0039]
Examples of phosphor materials generally used for PDP are listed below.
Red phosphor; (Y_xGd_1-x) BO₃: Eu³⁺
Green phosphor; Zn₂SiO₄: Mn
Blue phosphor; BaMgAl₁₀O₁₇: Eu³⁺(Or BaMgAl₁₄O₂₃: Eu³⁺)
As each phosphor material, for example, a powder having an average particle diameter of about 3 μm can be used. There are several methods of applying the phosphor ink. Here, a method of discharging the phosphor ink while forming a meniscus (cross-linking by surface tension) from a very fine nozzle called a known meniscus method is used. This method is convenient for uniformly applying the phosphor ink to the target area. Of course, the present invention is not limited to this method, and other methods such as a screen printing method can be used.
[0040]
Thus, the back panel 26 is completed.
Although the front panel glass 21 and the back panel glass 27 are made of soda lime glass, this is given as an example of the material, and other materials may be used.
2-3. Completion of PDP
The produced front panel 20 and back panel 26 are bonded together using sealing glass. Thereafter, the inside of the discharge space 38 is subjected to a high vacuum (8 × 10 8^-7The exhaust gas is evacuated to about Torr), and discharge gas such as Ne—Xe, He—Ne—Xe, He—Ne—Xe—Ar, etc. is sealed at a predetermined pressure (500-760 Torr).
[0041]
Thus, the PDP according to the present embodiment is completed.
Next, a method for forming the protective layer 242 will be described in detail.
3. Detailed method for forming protective layer
As described above, in order to produce the protective layer 242 with a good secondary electron emission amount, the present invention forms F centers in which two free electrons are trapped in the crystal structure. In order to form the F center, basically, the material (source material) of the protective layer 242 may be deposited by colliding with the surface of the dielectric layer body 241 in a high energy state. Specifically, the protective layer 242 is formed by any one of a sputtering method, a plasma CVD method, and an ion plating method described below while applying a negative bias voltage to the front panel 20.
[0042]
3-1. Method for forming protective layer by plasma CVD method
FIG. 3 is a schematic view of a plasma CVD apparatus.
The plasma CVD apparatus 40 is mainly composed of a CVD apparatus main body 45 in which a high frequency generator 47 is disposed, an Ar gas cylinder 41a (41b), a vaporizer 42 (43), and the like. In the figure, the CVD apparatus main body 45 and the vaporizers 42 and 43 have a cross-sectional structure. The front panel 20 is shown when the dielectric layer body 241 is formed over FIGS. 3 to 5 (the protective layer 242 is not yet formed).
[0043]
The high frequency generator 47 includes a high frequency generator 471 and a heating table 472 facing each other. The heating table 472 places the front panel 20 with the surface on which the dielectric layer 24 is formed facing upward, and heats the panel 20 by the plate heater 46. Note that a negative bias voltage is applied to the front panel 20 placed on the heating table 472 by a bias power supply 50. The high frequency generator 471 generates a high frequency inside the CVD apparatus main body 45 by a grounded high frequency power supply 48.
[0044]
The Ar gas cylinder 41a (41b) supplies Ar gas, which is a carrier gas, to the vaporizer (bubbler) 42 (43) via the valve C1 (C2) and the pipe L1 (L3).
The vaporizer 42 (43) is heated by a heater 42L (43L) and contains Al.₂O₃, MgAl₂O₃In addition, a metal chelate solution, acetylacetone, a cyclopentadienyl compound, or the like as a source material for any of MgO is kept warm and stored. These liquid source materials are mixed with Ar gas supplied to the vaporizer 42 (43) via the pipe L1 (L3), and sent to the CVD apparatus main body 45 via the pipe L2 (L4).
[0045]
In addition, as a metal chelate and a cyclopentadienyl compound, for example, as a source material for Mg, Magnesium Dipyvalyl Methane [Mg (C₁₁H₁₉O₂)₂], Magnesium Acetylacetone [Mg (C₅H₇O₂)₂], Cyclopentadienyl Magnesium [Mg (C₅H₅)₂], Magnesium Trifluoroaceticlacetone [Mg (C₂H₅F₃O₂)₂On the other hand, as a source material for Al, Aluminum Dipivalyl Methane [Al (C₁₁H₁₉O₂)₃], Aluminium Acetylacetone [Al (C₅H₇O₂)₃], Aluminum Trifluoroaceticlacetone [Al (C₅H₅F₃O₂)₃] Etc. are mentioned.
[0046]
Actually using such source materials, MgO, Al₂O₃, MgAl₂O₄When producing any of the above, MgO or Al₂O₃Is a single source material of Mg or Al, MgAl₂O₄Uses a source material of Mg and Al mixed at a molar ratio of 1: 2.
O₂The cylinder 44 is O which is a reactive gas.₂Gas is supplied to the CVD apparatus main body 45.
[0047]
The decompression pump 49 is for adjusting the internal pressure of the CVD apparatus main body 45, and appropriately discharges the gas in the CVD apparatus main body 45 to the outside through a pipe L6.
According to the plasma CVD apparatus 40 having the above configuration, when the protective layer 242 is formed, the front panel 20 is placed on the heating table 472 in advance, and the heating table 472 is brought to about 250 to 380 ° C. by the plate heater 46. Heat. Then, valves C1 to C3 are opened, Ar gas, source material, O₂Gas is fed into the CVD apparatus main body 45. Further, the internal pressure of the CVD apparatus main body 45 is adjusted to 30 to 300 Pa using the valves C1 to C3 and the decompression pump 49.
[0048]
Subsequently, the high frequency generator 47 is driven at a high frequency of, for example, 13.56 MHz by the high frequency power supply 48 to generate plasma in the CVD apparatus main body 45. Further, a negative bias voltage of −100 V to 150 V is applied to the front panel 20 using the bias power source 50. In this state, a source material is deposited on the surface of the dielectric layer body 241 to form the protective layer 242.
[0049]
3-2. Formation of protective layer by sputtering
FIG. 4 is a schematic view of a sputtering apparatus. In the drawing, the sputtering apparatus main body 65 has a cross-sectional structure.
The sputtering apparatus 60 includes a sputtering apparatus main body 65 having a high frequency generator 64 disposed therein, an Ar gas cylinder 61a, an O₂It is mainly composed of a gas cylinder 61b and the like.
[0050]
The high frequency generator 64 includes a high frequency generator 641, a heating table 642, and a plate heater 63, and the configuration is substantially the same as that of the high frequency generator 47. A negative bias voltage is applied to the front panel 20 placed on the heating table 642 by a bias power source 68. The high frequency generator 641 generates a high frequency (for example, 13.56 MHz) inside the CVD apparatus main body 65 by a grounded high frequency power supply 67.
[0051]
The high frequency generator 641 has MgO, Al as a protective layer material on the surface facing the front panel 20.₂O₃, MgAl₂O₄The solid source material (target material 62) is attached.
Ar gas cylinder 61a (O₂The gas cylinder 61b) is connected to the sputtering apparatus main body 65 via a valve C4 (valve C5) and a pipe L7 (piping L8), and can supply gas into the CVD apparatus main body 65.
[0052]
The decompression pump 66 is for adjusting the internal pressure of the CVD apparatus main body 65, and appropriately discharges the gas in the CVD apparatus main body 65 to the outside through the pipe L9.
According to the sputtering apparatus 60 having the above configuration, when forming the protective layer, the front panel 20 is placed on the heating table 642 with the dielectric layer main body 241 facing up, and the heating table 642 is set in advance by the plate heater 63 in advance. Heat to temperature (250 ° C. to 380 ° C.). Then, valves C4 and C5 are opened and Ar gas, O₂Each gas is introduced into the sputtering apparatus 60. Further, the internal pressure of the CVD apparatus main body 65 is adjusted to 0.1 Pa to 10 Pa by the decompression pump 66.
[0053]
Subsequently, the high frequency generator 67 is driven at a high frequency of, for example, 13.56 MHz by the high frequency power source 67, and plasma is generated in the main body 65 inside the CVD apparatus main body 65. Is applied to the front panel 20. Then, Ar ions are made to collide with the target material 62 and sputtered to form MgO, Al on the dielectric layer 24.₂O₃, MgAl₂O₄A protective layer 242 made of any of the above is formed.
[0054]
3-3. Method for forming protective layer by ion plating method
FIG. 5 is a schematic diagram of an ion plating apparatus. In the drawing, the ion plating apparatus main body 87 has a sectional structure.
The present ion plating apparatus 80 includes an ion plating apparatus main body 87 in which a heating table 82, a hollow cathode generation source 84, a plasma generation coil (high frequency generation unit) 85, and the like are arranged, an Ar gas cylinder 81a, and an O₂It is mainly composed of a gas cylinder 81b and the like.
[0055]
The heating table 82 is heated by the plate heater 81 and transfers heat to the front panel 20. In addition, a panel fixing device (not shown) is provided, and the front panel 20 is fixed to the table surface with the surface of the front panel 20 on which the dielectric layer body 241 is formed facing the plasma generating coil 85. .
The plasma generating coil 85 is connected to a high frequency power supply 89 and generates a high frequency (for example, 13.56 MHz) to generate Ar gas plasma inside the ion plating apparatus main body 87.
[0056]
The decompression pump 83 is for adjusting the internal pressure of the ion plating apparatus main body 87, and appropriately discharges the gas inside the ion plating apparatus main body 87 through the pipe L12.
Although the hollow cathode evaporation source 84 is not visible in the drawing, the cathode material has a cylindrical shape at the top, and the source material is disposed therein, and the source material is evaporated by the electric power supplied from the power source 89.
[0057]
According to the ion plating apparatus 80 having the above configuration, when the protective layer of the front panel 20 is formed, the heating table 82 on which the front panel 20 is fixed in advance is heated to 200 ° C. by the plate heater 81. Then, valves C6 and C7 are opened, Ar gas, O₂The gas is sent into the ion plating apparatus main body 87 from the pipes L10 and L11. Further, the internal pressure of the ion plating apparatus main body 87 is adjusted to 0.01 Pa to 1.0 Pa by the decompression pump 83.
[0058]
Subsequently, the plasma generating coil 85 is driven at a high frequency of, for example, (13.56 MHz) from the high frequency power supply 88 to generate plasma in the ion plating apparatus main body 87. At the same time, the hollow cathode evaporation source 84 is driven by the power source 89 to evaporate the source material and fill the ion plating apparatus main body 87. Then, a voltage of −1000 V is applied to the front panel 20 by the bias power source 86 to form a protective layer 242 on the dielectric layer body 241 of the front panel 20.
4). Production and performance measurement of examples and comparative examples
Next, the PDP of the present embodiment was manufactured according to the above manufacturing method, the peak of cathodoluminescence of the protective layer was measured, and the discharge start voltage Vf and the discharge sustain voltage Vm were measured.
[0059]
4-1. Production of PDP (Example No. 1 to 6) using protective layer by plasma CVD method
In the plasma CVD method with a negative bias voltage applied, a protective layer is prepared by changing the conditions such as the temperature of the vaporizer, the heating temperature of the front panel (FP), and the pressure inside the apparatus (atmosphere). The PDP used in Example No. 1-6.
[0060]
The specifications of the plasma CVD method at this time are as follows.
-Internal pressure of plasma CVD apparatus main body: 30 Pa to 300 Pa
Ar gas flow rate: 1 l / min
・ O₂Gas flow rate: 0.5 l / min
・ High frequency output: 300W (13.56MHz)
-Protective layer thickness formation rate: 0.9 μm / min
Here, the protective layer of each example is the same as that of Example No. 1-3, MgO, Example No. 4 and 5 are Al₂O₃, Example No. 6 is MgAl₂O₄It was.
[0061]
4-2. Production of PDP (Example Nos. 7 to 13) using a protective layer by sputtering
Next, in a sputtering method in which a negative bias voltage was applied, a protective layer was prepared by changing conditions such as the heating temperature of the FP and the pressure of the atmosphere. 7-13.
[0062]
Here, the protective layer of each example is the same as that of Example No. 7 and 8, MgO, Example No. 9 is Al₂O₃, Example No. 10 is MgAl₂O₄It was. In addition, Example No. 11 and no. 12 is a simple substance of Mg or Al and O by reactive sputtering.₂React with gas, MgO protective layer or Al₂O₃A protective layer was formed. Furthermore, Example No. 13, MgO having a thickness of 0.3 μm and (Al₂O₃) To form a protective layer.
[0063]
4-3. Production of PDP (Example No. 14 to 20) using protective layer by ion plating method
Next, in the ion plating method in which a negative bias voltage is applied, a protective layer is formed by changing conditions such as the heating temperature of the FP and the pressure of the atmosphere. 14-20.
[0064]
The specifications of the sputtering method at this time are as follows.
・ Internal pressure of main body of sputtering apparatus: 0.1 Pa to 10 Pa
Ar gas flow rate: 10cc / min
・ O₂Gas flow rate: 1cc / min
・ High frequency output: 500W (13.56MHz)
・ Thickness forming rate of protective layer: 0.3 μm / min
Here, the protective layer of each example is the same as that of Example No. 14 and 15, MgO, Example No. 16 and 17 Al₂O₃, Example No. 18 is MgAl₂O₄In addition, Example No. 19 and No. 20 and 20 are respectively formed of Mg or Al metal and O by reactive ion plating.₂React with gas, MgO protective layer or Al₂O₃A protective layer was formed.
[0065]
4-4. Production of PDP (Comparative Examples No. 1 to 3) using a protective layer by vacuum deposition
In each of the above Example Nos. In order to compare the performance with the PDPs 1 to 20, a protective layer was formed by using a vacuum vapor deposition method, which is a conventional method for producing a protective layer. 1-3.
In addition, as a vacuum evaporation method, MgO, Al₂O₃, MgAl₂O₄Each was vapor-deposited by heating with an electron beam. Moreover, the specification of the vacuum evaporation method at this time is as follows.
・ Internal pressure of vacuum evaporation system body: 0.1Pa
Ar gas flow rate: 10cc / min
・ O₂Gas flow rate: 1cc / min
・ Output of electron gun used for heating: 30kW
-Protective layer thickness formation rate: 0.9 μm / min
4-5. Cathodoluminescence measurement method
For each example and each comparative example, cathodoluminescence was measured in order to identify the presence of oxygen defects (F center) in the crystal structure of the protective layer.
[0066]
Specifically, a Xe flash lamp (L2435 manufactured by Hamamatsu Photonics) and a bandpass filter (BPF254 manufactured by Asahi Spectroscopy) with a narrow band (pass wavelength 254 nm) are combined to cause the Xe lamp to emit light in a dark room, and the light passing through the filter. Was condensed on the protective layer with a lens, and the cathodoluminescence of the protective layer was measured with a multichannel spectrometer (MCPD2000 manufactured by Otsuka Electronics Co., Ltd.).
[0067]
4-6. Method for measuring discharge start voltage Vf, discharge sustain voltage Vm and panel brightness
For each of the above examples and comparative examples, in order to investigate the effect of the F center of the protective layer, an AC power supply is connected to the display electrode of the PDP, a voltage is gradually applied, and the voltage at the time when the discharge starts is discharged over the entire surface. It was measured as the starting voltage Vf. Further, the voltage was lowered after the start of discharge, and the voltage immediately before the discharge disappeared was measured as the discharge sustaining voltage Vm.
[0068]
Further, the panel brightness was measured by the discharge sustain voltage when the entire panel was lit, and the brightness when driven at a frequency of 30 KHz was measured.
Example No. obtained in this way. 1-20 and Comparative Example No. Tables 1 to 4 below show the measurement results of the cathode luminescence and the panel luminance of 1 to 3 together with the protective layer production conditions, the Ne—Xe ratio of the discharge gas, and the like.
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[Table 1]

[0070]
[Table 2]

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[Table 3]

[0072]
[Table 4]

[0073]
5). Example performance evaluation
5-1. Example No. 1 to 6 (PDP produced by plasma CVD while applying a bias voltage) and Comparative Example No. Comparison with 1-3
As shown in Table 1, Example No. In the MgO protective layers 1 to 3, the emission peaks of 355 nm, 574 nm, 700 nm, and 975 nm were mainly observed in the cathodoluminescence regardless of the type of the source material. Comparative Example No. Compared to the MgO protective layer 1, only the emission peak at 700 nm coincides in these four PDP protective layers. This is the case with Example No. 1 to 3 and Comparative Example No. 1 In the MgO protective layer, an F center in which one free electron was trapped was formed. This suggests that two free electron-trapped F centers were formed in the MgO protective layers 1 to 3 (Phys. Rev. B. Volume. 1 No. 4, 15, Feb. 1970). reference).
[0074]
In addition, Example No. 4, 5 Al₂O₃As a result of measuring the cathodoluminescence of the protective layer, the emission peaks at 300 nm and 410 nm were similarly confirmed regardless of the source material. Comparative Example No. 2 Al₂O₃Compared with the protective layer, these three PDP protective layers have the same emission peak at 300 nm, indicating the presence of an F center that traps one free electron. 4, 5 Al₂O₃It seems that F center where two free electrons are trapped is formed in the protective layer.
[0075]
Next, Example No. 6 MgAl₂O₄As a result of measuring the cathode luminescence of the protective layer, emission peaks of 300 nm, 355 nm, 410 nm, and 700 nm were observed. 3 MgAl₂O₄In the protective layer, an emission peak of 300 nm is observed. Therefore, Example No. 6 and Comparative Example No. 3 is formed with an F center for trapping one free electron. It is considered that an F center trapping two free electrons was formed in 6.
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Next, Example No. 1-6 and Comparative Example No. Comparing the data of 1 to 3 as a whole, first, in the panel brightness, the comparative example No. 1-3 (about 400 cd / m²) In Example No. 1-6 (500 cd / m²) Is 100 cd / m²An improved result was measured. Next, in the discharge start voltage Vf, the comparative example No. 1-3 (around 250V), Example No. 1 to 6 (165 to 185 V) is reduced by a maximum of 80 V or more. 1 to 3 (about 190 to 200V). There are also cases where 1 to 6 (98 to 118 V) is reduced to about 100 V.
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Such Comparative Example No. Examples No. 1 to No. 3 The measurement results 1 to 6 show that the formation of the F center trapping two free electrons in the protective layer makes it possible to obtain abundant secondary electrons as compared with the conventional case, and the magnitude of plasma in the discharge space is two. Since secondary electrons could be expanded well even at low power, it is considered that very excellent performance was exhibited in both aspects of panel luminance and power efficiency related to discharge.
[0078]
From the data in Table 1, when a PDP is actually produced by plasma CVD using a bias voltage, a negative bias voltage of about −100 to −200 V is applied to the front panel under a pressure of about 30 to 300 Pa. It can be said that it is desirable to apply.
5-2. Example No. 7 to 13 (PDP produced by sputtering while applying a bias voltage) and Comparative Example No. Comparison with 1-3
As shown in Table 2, Example No. 7, 8, 11 and Comparative Example No. As a result of measuring the cathodoluminescence of the MgO protective layer of Example 1, The same emission peak as 1-6 was confirmed. Therefore, Example No. Based on the same considerations as 1 to 6 etc., Example No. 7, 8 and Comparative Example No. Both MgO protective layers have F centers that trap one free electron. 7 and 8, it seems that an F center in which two electrons were trapped was formed.
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In addition, Example No. 9, 12 Al₂O₃Each emission peak at 300 nm and 410 nm was confirmed in the protective layer. Of these, the emission peak at 410 nm is shown in Example No. Like 4 and 5, it seems to indicate the F center where two free electrons are trapped.
Furthermore, Example No. 10 and Comparative Example No. 3 MgAl₂O₄Comparing the protective layers, the 300 nm emission peak seen in both is the F center with one free electron trapped, and Example No. having other emission peaks. It can be seen that 10 indicates that F centers that trap two free electrons are formed.
[0080]
No. The protective layer 13 is MgO and Al₂O₃MgO and Al₂O₃It seems that both peaks were obtained.
Next, Example No. 7 to 13 and Comparative Example No. Comparing the data of 1 to 3 as a whole, in the panel brightness, the example No. As in Comparative Examples Nos. 1-6. 1-3 (about 400 cd / m²) In Example No. 7 to 13 (505 cd / m²Above) is 100 cd / m²An improved result was measured. Next, in the discharge start voltage Vf, the comparative example No. 1-3 (around 250V), Example No. 7 to 13 (around 185 to 195 V) and a voltage reduction effect of about 60 V were observed. Further, even with the sustaining voltage Vm, the comparative example No. 1 to 3 (about 190 to 200V). 7 to 13 (around 120V) is reduced to about 100V.
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Comparative Example No. Examples No. 1 to No. 3 The measurement results of 7 to 13 also show that the F center that traps two free electrons can obtain more secondary electrons than before, and the plasma can be expanded well even with low power by the secondary electrons. It shows that excellent performance was demonstrated in power efficiency and the like.
From the data in Table 2, when a PDP is actually produced by sputtering using a bias voltage, a negative bias of about −100 to −200 V is applied to the front panel under a pressure of about 0.1 to 10 Pa. It can be said that it is desirable to apply a voltage.
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5-3. Example No. 14-20 (PDP produced by ion plating while applying a bias voltage) and Comparative Example No. Comparison with 1-3
As shown in Table 3, Example No. As a result of measuring the cathodoluminescence of the protective layer with respect to 14 to 20 PDPs, 14, 15, 19 MgO protective layer, Example No. 16, 17, 20 Al₂O₃Protective layer, Example No. 18 MgAl₂O₄For each of the protective layers, the same emission peaks as those in Table 1, Table 2, and Table 4 were confirmed. That is, these Example Nos. It was shown that F centers for trapping one and two free electrons were formed in the 14 to 20 protective layers.
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Next, Example No. 14-20 and Comparative Example No. Comparing the data of 1 to 3 as a whole, in the panel brightness, the example No. Almost the same as Comparative Examples No. 1 to No. 13 1-3 (about 400 cd / m²) In Example No. 4-20 (505 cd / m²Above) is 100 cd / m²An improved result was measured. In particular, Example No. Each of 20, 16, 25 Al₂O₃In the protective layer, 530 cd / m each²540 cd / m²525 cd / m²And a relatively high panel brightness.
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In the discharge start voltage Vf, the comparative example No. 1-3 (around 250V), Example No. The effect which can implement | achieve a low voltage to 14-20 (around 160-175V) and about 75V was seen. Further, in the sustaining voltage Vm, the comparative example No. 1 to 3 (about 190 to 200V). 14-20 (around 105V) is reduced to about 100V. Regarding these Vm and Vf, Example No. The result that 20 was the best in balance was obtained (Vf = 160V, Vm = 100V).
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Thus, Example No. The reason why 20 is superior in both panel luminance and power efficiency is considered to be due to the large amount of secondary electrons emitted.
Comparative Example No. Examples No. 1 to No. 3 In the measurement results of 14 to 20, the F center which traps two free electrons can obtain abundant secondary electrons as compared with the conventional case, and the plasma can be favorably expanded by the secondary electrons even at low power. This seems to indicate that excellent performance was demonstrated in terms of efficiency.
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From the data in Table 3, when a PDP is actually manufactured by an ion plating method using a bias voltage, the pressure is about 0.01 to 1.0 Pa and the front panel is about -100 to 200 V. It can be said that it is desirable to apply a negative bias voltage.
6). Other matters
In the above-described embodiments and examples, an example of manufacturing a high-definition type PDP has been described, but the present invention is naturally not limited to this, and may be applied to another standard PDP or gas discharge panel.
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Furthermore, the discharge gas is not limited to the Ne—Xe system, and other discharge gases may be used.
In the above embodiments and examples, an example in which a negative bias voltage is applied to the protective layer has been described. However, the present invention is not limited to this, and high-frequency generation such as a plasma CVD apparatus, a sputtering apparatus, and an ion plating apparatus is performed. It is sufficient that a voltage difference corresponding to the negative bias voltage can be provided between the unit and the front panel.
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In the present invention, any of a plasma CVD apparatus, a sputtering apparatus, and an ion plating apparatus may be combined, and thereby, for example, different materials may be laminated to form a protective layer.
Further, magnesium oxide MgO, aluminum oxide Al as metal oxides constituting the protective layer of the present invention₂O₃Spinel MgAl₂O₄However, the protective layer may be formed by combining any of these, or the protective layer may be composed of other materials.
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Furthermore, although the said embodiment and Example showed the example which laminated | stacked a protective layer on the dielectric layer main body, and made this into a dielectric layer, the dielectric layer main body was comprised from the said metal oxide, and a protective layer was formed. A configuration may be omitted.
Further, as one of the methods for facilitating formation of the F center in which two free electrons are trapped, O in an atmosphere inside a plasma CVD apparatus, a sputtering apparatus, an ion plating apparatus or the like.₂Reduce the concentration or H₂It has been clarified by another experiment that the F center is effectively formed by adding a reducing gas such as. In the present invention, the F center may be formed by using such a method together.
[0090]
【The invention's effect】
As is apparent from the above, the present invention is arranged so that the first plate and the second plate having the first electrode and the dielectric layer formed on the surface in that order, and the second plate face the dielectric layer. A gas discharge panel provided, wherein the dielectric layer has at least a surface facing the second plate made of a metal oxide, and two free electrons are present in the crystal structure of the metal oxide. Since trapped oxygen vacancies are contained, the discharge scale is favorably expanded by the two free electrons without increasing the power consumption, and the panel luminance is improved. In addition, since the number of electrons during discharge becomes rich due to the free electrons, the discharge delay can be improved and the scanning speed can be expected to be improved. Therefore, it is possible to drive with a lower driving voltage than before and to obtain good light emission efficiency, and it is possible to realize an excellent gas discharge panel such as a high-vision type PDP.
[0091]
Such a gas discharge panel of the present invention includes a first step of forming a dielectric layer on the surface of the first plate on which the first electrode is formed, and the first plate surface and the second plate surface facing each other. A gas discharge panel manufacturing method comprising a second step of attaching, in the first step, using a device selected from a plasma CVD device, a sputtering device, and an ion plating device, It is possible to manufacture by forming a dielectric layer made of a metal oxide at least on the surface portion facing the second plate while applying a bias voltage to the other plate.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional perspective view of an AC surface discharge type PDP that is an application example of the present invention.
FIG. 2 is a partial cross-sectional view in the thickness direction of a PDP.
FIG. 3 is a schematic view of a plasma CVD apparatus.
FIG. 4 is a schematic view of a sputtering apparatus.
FIG. 5 is a schematic view of an ion plating apparatus.
[Explanation of symbols]
20 Front panel
21 Front panel glass
22, 23 Display electrode
24 Dielectric layer
26 Back panel
28 Address electrodes
38 Discharge space
40 Plasma CVD equipment
41a, 41b, 61a Ar gas cylinder
42, 43 vaporizer
42L, 43L Liquid source material (metal chelate and cyclopentadienyl compound)
42H, 43H heater
44, 61b O2 gas cylinder
45 Plasma CVD equipment body
46, 63, 81 Plate heater
47, 64 high frequency generator
48, 67, 88 High frequency power supply
49, 66, 83 Pressure reducing pump
50, 64, 86 Bias power supply
60 Sputtering equipment
62 Target material (solid source material)
65 Sputter device body
80 Ion plating equipment
82, 472, 642 Heating table
84 Hollow cathode evaporation source
85 Plasma generating coil
89 Power supply
241 Dielectric layer body
242 protective layer
471, 641 High frequency generator
C1-C7 valve
L1-L12 piping

Claims (7)

A first plate having a first electrode and a dielectric layer formed on a surface thereof in that order; and a second plate, a gas discharge panel disposed to face the dielectric layer,
The dielectric layer has at least a surface facing the second plate made of a metal oxide, and the crystal structure of the metal oxide includes an oxygen defect in which two free electrons are trapped. A gas discharge panel characterized by that. The gas discharge panel according to claim 1, wherein the metal oxide is selected from magnesium oxide, aluminum oxide, and spinel. A gas discharge comprising a first step of forming a dielectric layer on the surface of the first plate on which the first electrode is formed, and a second step of attaching the first plate surface and the second plate surface to face each other A method of manufacturing a panel,
In the first step, an apparatus selected from a plasma CVD apparatus, a sputtering apparatus, and an ion plating apparatus is used, and a bias voltage is applied between the high frequency generator of the apparatus and the first plate, and at least a second voltage is applied. A method of manufacturing a gas discharge panel, wherein a dielectric layer made of a metal oxide is formed on a surface portion facing a plate. The method for manufacturing a gas discharge panel according to claim 3, wherein the metal oxide of the dielectric layer formed in the first step is selected from magnesium oxide, aluminum oxide, and spinel. In the first step, a layer made of the metal oxide is formed by a plasma CVD apparatus while applying a negative bias voltage of −100 V to −200 V to the first plate under a pressure of 30 Pa to 300 Pa. The method of manufacturing a gas discharge panel according to claim 3 or 4, wherein: In the first step, the metal oxide layer is formed by a sputtering apparatus while applying a negative bias voltage of −100 V to −200 V to the first plate under a pressure of 0.1 Pa to 10 Pa. The method of manufacturing a gas discharge panel according to claim 3 or 4, In the first step, while applying a negative bias voltage of −500 V to −1500 V to the first plate under a pressure condition of 0.01 Pa to 1.0 Pa, the ion plate is used to remove the metal oxide from the metal oxide. The method for producing a gas discharge panel according to claim 3 or 4, wherein a layer to be formed is formed.

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