JP4013340B2 - Plasma display components - Google Patents

Description

【００８５】
また、実施例１〜３と同一の手法により、以下内容の誘電体層Ａ、Ｂを形成した（実施例４〜６）。
【００８６】
誘電体層Ａの厚みを１０μｍに固定し、誘電体層Ｂの厚みを変えた場合に得られた誘電体層Ａの光学濃度（ＯＤ値）、誘電体層Ｂの全光線反射率を表２に示す。
【００８７】
【表２】

【００８８】
さらに誘電体層ＡおよびＢの厚みを調整して表３に示す誘電体層ＡのＯＤ値、誘電体層Ｂの全光線反射率を有する誘電体層を形成した（比較例１、２）。
【００８９】
【表３】

【００９０】
３．隔壁形成
実施例１〜６および比較例１、２で得られた誘電体層Ａ、誘電体層Ｂからなる多層構造の誘電体層上に次のようにして隔壁を形成した。
【００９１】
感光性ポリマ（Ｘ−４００７）の３４％γ−ブチロラクトン溶液３２ｇ、感光性モノマ（ＭＧＰ４００）１０．５ｇ、光重合開始剤（ＩＣ−３６９）３．４ｇ、増感剤（ＤＥＴＸ−Ｓ）３．４ｇ、紫外線吸光剤（スダンIV）０．０４ｇ、下記の組成と特性を有するガラス成分４９ｇの割合で混合・予備混練した後、三本ロールにかけて感光性ペーストを作製する。
【００９２】
ガラスの組成：
酸化リチウム９％、酸化珪素２０％、酸化硼素３１％、酸化バリウム４％、酸化アルミニウム２４％、酸化亜鉛２％、酸化マグネシウム６％、酸化カルシウム４％。
【００９３】
ガラスの特性：
平均粒径２．６μｍ、ガラス転移点４８０℃、軟化点５２０℃、熱膨張係数７９×１０^-7／Ｋ。
【００９４】
感光性ペーストを乾燥厚み１８０μｍになるようにスクリーン印刷を複数回繰り返して塗布した。塗布膜上にフォトマスク（ストライプ状パターン、ピッチ１５０μｍ、線幅２０μｍ）を置いて、１２ｍＷ／ｃｍ²の出力の超高圧水銀灯の露光機で露光し、０．６Ｊ／ｃｍ²の露光量を与えた。
【００９５】
その後、３５℃に保持したモノエタノールアミンの０．２％水溶液を１２０秒間シャワーすることにより現像し、さらに水洗した。これにより形状の優れた隔壁パターンが形成され、未露光部のペースト塗布膜が除去された部分には誘電体層の表面が露出した。隔壁パターンは空気中５７０℃で１５分間焼成され、電子顕微鏡で観察して隔壁の高さは１３０μｍであり、線幅（半値幅）は３３μｍであった。
【００９６】
４．蛍光体形成およびパネル作製
前記３で得られた誘電体層上に隔壁を形成した基板に、ノズル塗布法で蛍光体ペーストを塗布し、焼成し蛍光体層を形成してプラズマディスプレイ用の背面ガラス基板を作製した。別途作製された前面ガラス基板と前記背面基板を封着し、放電セルにＸｅ−Ｈｅ混合ガスを封入し、配線を実装して作製されたプラズマディスプレイを得た。
【００９７】
５．評価
パネル放電時の評価を目視により行い、その結果を表４に示す。
【００９８】
【表４】

【００９９】
表４より、本発明の実施例により得られたプラズマディスプレイパネルは、ハレーションの発生が無く非常に高い輝度が得られることが分かる。
【０１００】
略記号の説明
Ｘ−４００７：
４０％メタクリル酸、３０％メチルメタクリレート、３０％スチレンからなる共重合体のカルボキシル基に対して０．４当量のグリシジルメタクリレートを付加反応させた重量平均分子量４３，０００、酸価９５の側鎖にカルボキシル基とエチレン性不飽和基を有するポリマ。
【０１０１】
ＭＧＰ４００：下記の化学式で示される化合物
【化１】

【０１０２】
ＩＣ−３６９：Irgacure-369（チバ・ガイギー社製品）
２−ベンジル−２−ジメチルアミノ−１−（４−モルフォリノフェニル）ブタノン−１
ＤＥＴＸ−Ｓ：２，４−ジエチルチオキサントン
スダンIV：紫外線吸収剤（東京化成工業（株）製）
【０１０３】
【発明の効果】
本発明のプラズマディスプレイ用部材は、基板上に少なくとも電極層、誘電体層Ａ、誘電体層Ｂ、隔壁および蛍光体層を順次形成した部材であって、該誘電体層Ａが光学濃度（ＯＤ値）０．５以上の黒色層、該誘電体層Ｂが全光線反射率４０％以上の白色層であるため、ハレーションの発生を防ぎ、高輝度の表示が可能な高品位のプラズマディスプレイ用部材を得ることができる。[0001]
BACKGROUND OF THE INVENTION
The present invention is a member for plasma display, in particular, appearance quality, whiteness is excellent, and halation does not occur. Especially when used in a plasma display panel (also called plasma display), extremely high front luminance and display quality can be obtained. The present invention relates to a plasma display member having a dielectric layer formed thereon.
[0002]
[Prior art]
In recent years, plasma displays have attracted attention as large displays. A plasma display can display at a higher speed than a liquid crystal panel and can be easily increased in size, and thus has penetrated into fields such as OA equipment and public information display devices. Progress in the field of high-definition television is also highly expected. Along with such expansion of applications, a color plasma display having a large number of display cells has attracted attention.
[0003]
The plasma display is configured by bonding a front substrate and a rear substrate. In the front substrate, a transparent electrode made of ITO or tin oxide is formed on the back surface of the glass substrate. A plurality of transparent electrodes are formed in a strip shape. A pulse AC voltage of 10 kHz to several tens of kHz is usually applied between the adjacent transparent electrodes to obtain a display discharge. The sheet resistance of the transparent electrode is several tens of ohms / cm.²Therefore, the electrode resistance is about several tens of kΩ, and the applied voltage pulse does not rise sufficiently and driving becomes difficult. Therefore, a resistance value is lowered by forming a normal metal bus electrode on the transparent electrode. These electrodes are covered with a transparent dielectric layer (insulating layer). For the transparent dielectric layer, low-melting glass is used. A MgO layer is formed thereon as a protective layer by electron beam evaporation. The dielectric layer formed on the front substrate has a role as a capacitor for accumulating electric charges for discharge.
[0004]
On the other hand, on the back substrate, a data electrode for writing display data is manufactured, covered with a dielectric layer (insulating layer), a partition is formed on the electrode, and red, green, and blue are provided between the partitions. After applying the phosphor paste that emits light, the phosphor layer is formed by drying and baking.
[0005]
The front substrate and the rear substrate are aligned and sealed so that they can be driven by matrix, then exhausted, mixed gas such as He-Xe, Ne-Xe, etc. is encapsulated, and the driving circuit is mounted to form a plasma display. Make it.
[0006]
When a pulsed alternating voltage is applied between adjacent transparent electrodes, a gas discharge occurs and plasma is formed. The ultraviolet rays generated here excite the phosphor to emit visible light, and display light emission is obtained through the front substrate.
[0007]
When producing a plasma display in this way, the influence of alkali metal ions in the dielectric layer, specifically by the ion exchange reaction with metal ions such as silver used in the electrodes and tin contained in the glass substrate. There has been a problem that discoloration of the dielectric layer reduces display quality. On the other hand, the dielectric layer is preferably capable of increasing the luminance by reflecting light emitted from the phosphor. The function of the dielectric layer interposed between the electrode and the phosphor layer, It is important to balance so that the barrier ribs and the phosphor layer can be formed without problems.
[0008]
[Problems to be solved by the invention]
It is an object of the present invention to provide a plasma display member that prevents halation from occurring and has high display quality.
[0009]
[Means for Solving the Problems]
An object of the present invention is a member in which at least an electrode layer, a dielectric layer A, a dielectric layer B, a partition wall and a phosphor layer are sequentially formed on a substrate, and the dielectric layer A has an optical density (OD value). It can be achieved by a member for a plasma display, wherein the black layer is 0.5 or more and the dielectric layer B is a white layer having a total light reflectance of 40% or more.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The substrate used for the plasma display member of the present invention is soda glass or high strain point glass (for example, PD-200 manufactured by Asahi Glass Co., Ltd.).
[0011]
As a material for the electrode layer formed on these substrates, a material containing 80% by weight or more, preferably 95% by weight or more of silver is preferably used from the viewpoint of resistance value and adhesion to the substrate. Moreover, the electrode layer excellent in adhesiveness with a board | substrate can be obtained by containing 1 to 5 weight% of glass frit components in an electrode layer.
[0012]
In the present invention, the thickness of the electrode layer is preferably 2 to 10 μm. When the electrode layer thickness is within the above range, sufficient conduction can be obtained, and defects such as panel defects do not occur. On the other hand, if the above range is exceeded, cracks are likely to occur in the dielectric layer described later, which is not preferable.
[0013]
In the present invention, the method for forming the electrode layer is not particularly limited, and a known technique, for example, a so-called screen printing method in which an ordinary conductive paste is printed using a screen plate having a desired pattern, or ordinary photosensitivity. A so-called photolithography method in which a conductive paste is used, and after the photosensitive conductive paste is applied onto a substrate, pattern exposure is performed through a photomask having a desired pattern, and development can be applied.
[0014]
In the present invention, a dielectric layer A, which is a black layer made of an inorganic material, and a dielectric layer B, which is a white layer, are formed on a substrate on which an electrode layer is formed. When the dielectric layer is only a white layer, it is difficult to prevent light from penetrating into the substrate during discharge, and light is repeatedly reflected inside the substrate and emitted to the display surface side, so the phenomenon that the image is blurred white (halation) is likely to occur. . In order to prevent light from entering the substrate, it is effective to make the dielectric layer a black layer. However, when only the black layer is used, the front luminance is lowered during discharge. Therefore, in the present invention, the dielectric layer is a white layer (dielectric layer B) having a total light reflectance of 40% or more on a black layer (dielectric layer A) having an optical density (OD value) of 0.5 or more. By providing this, the light emitted to the substrate side is reflected, and the front luminance can be increased.
[0015]
If the optical density (OD value) of the dielectric layer A is less than 0.5, a sufficient antihalation effect cannot be obtained.
[0016]
The dielectric layer B plays a role of increasing the luminance of the display light by efficiently reflecting the light emitted from the phosphor layer formed thereon to the front. For this reason, it is necessary to increase the reflectance by whitening, and in the present invention, the brightness of the plasma display can be increased and bright display can be achieved by maintaining the total light reflectance at 40% or more. . If the total light reflectance is less than 40%, sufficient luminance cannot be obtained.
[0017]
In the present invention, the reflectance of the dielectric layer is measured using a self-recording spectrophotometer UV-3101PC type (manufactured by Shimadzu Corporation). The total light reflectance is obtained by measuring the total reflection of light incident at an incident angle of 8 degrees. At this time, a barium sulfate plate was used as a 100% reflector (sub-white plate).
[0018]
The optical density (OD value) of the dielectric layer can be calculated as OD = −logTt, where Tt is the total light reflectance, but it can be easily measured with a Macbeth densitometer (manufactured by Macbeth).
[0019]
By forming the dielectric layer on the electrode layer, peeling and falling are less likely to occur when the partition is formed. In particular, when the barrier ribs are formed by a photosensitive paste method, internal stress due to the difference in photocuring between the upper and lower barrier ribs is likely to occur, and defects such as peeling are likely to occur when the barrier ribs are fired. Forming a dielectric layer under the partition wall layer is effective in improving the yield because such a defect can be prevented.
[0020]
The thickness of the dielectric layer, that is, the total thickness of the dielectric layer A and the dielectric layer B is preferably 1.1 to 5.0 times the electrode thickness, which is a range in which unevenness due to the electrode layer thickness is eliminated as much as possible. Specifically, it is preferably 3 to 30 μm, more preferably 4 to 25 μm. When the dielectric layer is thick, the binder removal property is lowered during firing, so that cracks are likely to occur, and the substrate is warped due to a large stress applied to the substrate. On the other hand, if it is too thin, there is flatness and it is difficult to form a uniform and dense dielectric layer.
[0021]
Glass is mainly used as the inorganic material constituting each dielectric layer. However, since dielectric layer A is formed in contact with the electrode, it cannot be used that contains an active component in contact with silver used as the electrode material. . When the glass of the dielectric layer A contains an alkali metal, there arises a problem that the dielectric layer is colored by causing an ion exchange reaction with silver ions derived from the electrode. In order to avoid this problem, it is preferable to use glass that does not substantially contain an alkali metal. “Substantially not contained” means that it is 0.5% by weight or less, more preferably 0.1% by weight or less even if it is contained.
[0022]
In the present invention, since the dielectric layer is formed by baking on a soda glass substrate or a high strain point glass substrate, it is essential that the glass substrate can be baked in a temperature range of 550 to 600 ° C. that does not cause thermal deformation of the glass substrate. . Accordingly, the inorganic material constituting each dielectric layer is preferably composed mainly of glass having a glass transition point of 400 to 550 ° C. and a softening point of 400 to 600 ° C. When the glass transition point and the softening point are lower than 400 ° C., the glass melts during the subsequent process, and the uniformity and characteristics of the thickness of the dielectric layer deteriorate. Further, when the glass transition point is higher than 550 ° C. or the softening point is higher than 600 ° C., firing on the glass substrate becomes insufficient, and the dielectric layer is likely to be peeled off or missing.
[0023]
Further, the glass component has a glass transition point and a softening point in the above ranges, and a thermal expansion coefficient α in the range of 50 to 400 ° C.₅₀~₄₀₀Value of 70-85 × 10^-7/ K, more preferably 72-80 × 10^-7/ K is preferable because it matches the thermal expansion coefficient of the substrate glass and reduces the stress applied to the glass substrate during firing. 85 × 10^-7If it exceeds / K, a stress that warps the substrate on the surface on which the dielectric layer is formed is applied.^-7If it is less than / K, stress is applied such that the substrate is warped on the surface side without the dielectric layer. For this reason, if heating and cooling of the substrate are repeated, the substrate may break. Further, when sealing with the front substrate, the two substrates may not be parallel and cannot be sealed due to warpage of the substrates.
[0024]
In the present invention, the dielectric layer A is preferably substantially free of alkali metal as described above, and is preferably composed mainly of glass having the above-mentioned thermal characteristics. Examples thereof include lead glass and bismuth glass, but are not particularly limited.
[0025]
In the case of the present invention, using bismuth-based glass, particularly glass containing 10 to 70% by weight of bismuth oxide has advantages such as paste stability. If the added amount of bismuth oxide exceeds 70% by weight, the heat-resistant temperature of the glass becomes too low and baking on the glass substrate becomes difficult.
[0026]
Further, the dielectric layer A needs to be a black layer having an optical density of 0.5 or more, and for this purpose, it is preferable to include a black pigment.
[0027]
Although it does not specifically limit with the black pigment as used in the field of this invention, At least 1 type in Cr, Co, Fe, Mn, Ni, RuMetal oxideIs preferably used.
[0028]
In the present invention, the inorganic material forming the dielectric layer A contains 50 to 98% by weight of glass having a glass transition point of 400 to 550 ° C. and a softening point of 400 to 600 ° C. and 2 to 50% by weight of a black pigment. Is preferred.
[0029]
As a specific example of the composition of the glass used to form the dielectric layer A, in oxide conversion notation,
Bismuth oxide 10-70% by weight
3-30% by weight of silicon oxide
Boron oxide 10-30% by weight
Zinc oxide 10-40% by weight
2-6% by weight of iron oxide
Cobalt oxide 2-6% by weight
However, it is not limited to this.
[0030]
In the glass composition, bismuth oxide is blended in the range of 10 to 70% by weight. If it is less than 10% by weight, it is less effective for controlling the baking temperature and the softening point. If it exceeds 70% by weight, the heat-resistant temperature of the glass becomes too low and baking onto the glass substrate becomes difficult.
[0031]
Silicon oxide can be blended in the range of 3 to 30% by weight, but if it is less than 3% by weight, the denseness, strength and stability of the glass layer are reduced, and there is a mismatch between the glass substrate and the thermal expansion coefficient. Deviate from the value of. When it exceeds 30% by weight, the glass transition point and the softening point are increased, and the heat resistant temperature is increased. For this reason, it becomes difficult to be baked densely on a glass substrate at 600 ° C. or lower, air bubbles remain, and electrical insulation properties are lowered.
[0032]
By blending boron oxide in the range of 10 to 30% by weight, electrical, mechanical and thermal characteristics such as electrical insulation, strength, thermal expansion coefficient, and denseness of the insulating layer can be improved.
[0033]
Zinc oxide is preferably added in the range of 10 to 40% by weight. If it is less than 10% by weight, there is no effect of improving the density, and if it exceeds 40% by weight, the baking temperature becomes too low to control, and the insulation resistance becomes low, which is not preferable.
[0034]
It is preferable that each of the black pigments such as iron oxide and cobalt oxide is added in a range of 2 to 6% by weight in order to impart black color. If it is less than 2% by weight, it is difficult to obtain a black color having an optical density (OD value) of 0.5 or more. If it exceeds 6% by weight, the characteristics of the dielectric layer may be impaired.
[0035]
In addition to iron oxide and cobalt oxide, chromium oxide, manganese oxide, nickel oxide, ruthenium oxide and the like can be preferably used as the black pigment in the above composition.
[0036]
Moreover, as glass which is a main component of the dielectric layer B, like the dielectric layer A, normal lead borosilicate glass or bismuth glass can be used, and is not particularly limited.
[0037]
As a typical composition of the bismuth-based glass that is preferably used as the dielectric layer B in the present invention, an oxide conversion notation,
Bismuth oxide 10-70% by weight
3-30% by weight of silicon oxide
Boron oxide 10-30% by weight
Zinc oxide 10-40% by weight
Zirconium oxide 1-10% by weight
However, it is not limited to this.
[0038]
In the present invention, the dielectric layer B contains the above-described composition components, contains 50 to 90% by weight of glass having a glass transition point of 450 to 550 ° C. and a softening point of 500 to 600 ° C. and 10 to 50% by weight of filler. It is preferable to do. Examples of the filler include high melting point glass and ceramics having a softening point of 600 ° C. or higher, and at least one selected from the group consisting of titania (titanium oxide), alumina, silica, barium titanate, and zirconia, which are white fillers. It is preferable to use it.
[0039]
In the present invention, the average particle size of the filler is preferably 0.15 to 5.00 μm, more preferably 0.15 to 4.00 μm. When the average particle diameter of the filler is less than 0.15 μm, the whiteness is lowered and it is difficult to obtain a desired reflectance. On the other hand, if it exceeds 5.00 μm, the smoothness and denseness of the dielectric layer are lowered, which is not preferable.
[0040]
By adding such a filler, the shrinkage rate during firing is reduced, and the internal stress of the formed dielectric layer B is reduced, so that the partition wall formed on the dielectric layer B is cracked or peeled off, etc. Generation of defects can be suppressed, and it can contribute to reducing the warpage of the glass substrate. In the present invention, by selecting and adding a white filler, the formed dielectric layer B exhibits a white color, which reflects the display light well, thereby improving the brightness of the panel and improving the purity of the display color. Also effective.
[0041]
In the present invention, the dielectric layer is formed by, for example, applying and drying a dielectric paste a composed of an inorganic material and an organic component to form a paste layer of the dielectric layer A, and then using the dielectric paste b by the same method. It can be formed by forming a paste layer of the body layer B and firing them.
[0042]
In the dielectric paste A and dielectric paste b for forming the dielectric layer A and dielectric layer B, an organic component is used as a binder for dispersing and blending the above-described glass and black pigment, glass or an inorganic material composed of glass and filler. Is used.
[0043]
As the organic component, polyvinyl alcohol, polyvinyl butyral, methacrylic acid ester polymer or copolymer, acrylic acid ester polymer or copolymer, cellulosic resin, and the like can be used. Cellulosic resins are preferred in that they have good binder removal properties during firing.
[0044]
In the present invention, the dielectric layer has a multilayer structure of at least two layers (in the case of two layers, the B layer and the A layer from the top), and the dielectric paste coating film and the photosensitive paste forming the uppermost layer This method is also applied to a method of manufacturing a plasma display substrate by simultaneously baking the barrier rib pattern formed in step 1. In such a case, the organic component of the dielectric paste is the same as that used for forming the barrier rib pattern. It is considered preferable to apply these organic components from the viewpoints of affinity and debinding in simultaneous firing. Therefore, the dielectric paste may have photosensitivity, and its function can be used effectively, but when a component that absorbs active light such as a photopolymerization initiator and initiates a photoreaction is not added. It can be handled in the same manner as other binder components.
[0045]
The viscosity of each dielectric paste is adjusted using a solvent that dissolves the binder component. As the solvent, methyl cellosolve, methyl cellosolve acetate, ethyl cellosolve, ethyl cellosolve acetate, butyl cellosolve, butyl cellosolve acetate, methyl ethyl ketone, acetone, dioxane, cyclopentanone, tetrahydrofuran, ethyl alcohol, isopropyl alcohol, dimethyl sulfoxide, γ-butyrolactone, Examples include, but are not limited to, terpineol or a mixture thereof.
[0046]
The amount of the inorganic material used for each dielectric paste is preferably 50 to 90% by weight with respect to the sum of the inorganic material and the organic component. If it is less than 50% by weight, the dielectric layer lacks the denseness and surface flatness, and if it exceeds 90% by weight, the paste viscosity increases and the thickness unevenness during application increases.
[0047]
The viscosity of each dielectric paste is 3000 to 80,000 cps (centipoise), more preferably 4000 to 60,000 cps. If the viscosity is within this range, the shrinkage during firing is formed when the dielectric layer is formed on the electrode layer. This is preferable because it has the effect of suppressing cracks in the dielectric layer caused by stress. If it is less than 3000 cps, uneven coating tends to occur, and if it exceeds 80,000 cps, the firing shrinkage force tends to concentrate near the electrode layer, and cracks are likely to occur.
[0048]
Further, each dielectric paste may contain a plasticizer, and dibutyl phthalate, dioctyl phthalate, polyethylene glycol, glycerin and the like are used.
[0049]
In the present invention, the dielectric layer only needs to be composed of at least A and B2 layers. For example, even if the glass component constituting the dielectric layer is common, for example, one layer includes a filler component, and the other This layer does not contain a filler, but the generated dielectric layer A is a black layer having an optical density of 0.5 or more, and the dielectric layer B is a white layer having a total light reflectance of 40% or more. It only needs to satisfy the conditions. The components constituting each dielectric paste may be quantitatively or qualitatively different.
[0050]
Each dielectric paste is applied to the substrate and then fired, but after applying the dielectric paste, a barrier rib pattern is formed using the barrier rib paste, and in some cases, all the dielectric layers and the barrier rib pattern are simultaneously fired, A uniform partition wall layer that does not peel off or collapse can be formed.
[0051]
In the present invention, the barrier rib pattern is applied by selecting various methods such as a sand blast method, a screen printing method, a mold transfer method, and a photolithography method (photosensitive paste method). In the present invention, the photosensitive paste method is preferably applied because it can be formed. In the photosensitive paste method, a photosensitive paste mainly composed of an inorganic component composed of glass powder and an organic component having photosensitivity is applied on a glass substrate on which a dielectric layer or a dielectric paste coating film is formed, and is passed through a photomask. Exposure and development to form a barrier rib pattern, followed by baking to obtain barrier ribs.
[0052]
Since the partition pattern formed by the photosensitive paste method is likely to be subjected to distortion stress due to non-uniformity of photocuring in the thickness direction, peeling is likely to occur during firing. When separation of the barrier ribs occurs, color mixture occurs at the part where the barrier ribs are peeled off, and the peeled barrier ribs remain on the panel to crush pixels, thereby reducing the yield of plasma display manufacturing. In order to suppress this, the barrier rib pattern is formed on the unfired dielectric layer, and the barrier rib pattern and the entire dielectric layer are fired at the same time, which is preferable in that peeling is suppressed and the yield is improved.
[0053]
The height of the barrier ribs is 70 to 160 μm, and the thickness of the photosensitive paste coating film applied for the barrier rib pattern formation needs to be 100 to 220 μm in consideration of firing shrinkage. In order to expose a high-definition pattern on the photosensitive paste coating film having such a thickness and to form a high aspect ratio pattern with high resolution, the actinic light for exposure is as straight as possible to the bottom of the coating film. It is essential to make it permeate. For this reason, it is important that both the glass component and the photosensitive organic component blended in the photosensitive paste are selected so as to have high light transmittance, and these are uniformly mixed. Furthermore, in a mixture system in which glass powder is dispersed in a photosensitive organic component such as a photosensitive paste, the average refractive index of each of these components is approximate to increase the light transmittance. Most important.
[0054]
In general, the refractive index of the organic component is 1.45 to 1.7, but the refractive index of the glass component is higher, so in order to match the refractive index of both, the average refractive index of the glass component is It is most preferable to control to 1.5 to 1.7 so that the difference from the average refractive index of the organic component is about ± 0.05. From this point, the glass component of the photosensitive paste used for the barrier rib formation has an average refractive index of 1.5 to 1.7, a glass transition point of 450 to 550 ° C, and a softening point of 500 to 600 ° C. preferable. Further, since the thermal characteristics may be fired at the same time as the uppermost film of the dielectric layer, it is preferable that the thermal characteristics be the same or approximate.
[0055]
As the glass component for photosensitive paste satisfying the above conditions, those having the following components and blending amounts are used. That is, in oxide equivalent notation,
Lithium oxide 2-10% by weight
Silicon oxide 8-40% by weight
Boron oxide 20-50% by weight
2-15% by weight of barium oxide
Aluminum oxide 8-30% by weight
However, the present invention is not limited to this.
[0056]
In the glass component of the barrier rib-forming photosensitive paste, it is possible to add a filler component similar to that blended in the dielectric layer, thereby reducing the shrinkage ratio during firing of the barrier rib pattern, and the pattern formation. This facilitates the shape retention during firing.
[0057]
The dielectric material used in the present invention and the glass powder for barrier ribs are prepared by mixing compounds such as bismuth, lithium, silicon, aluminum, boron, and barium as raw materials so as to have a predetermined composition. , After melting at 900 to 1200 ° C., rapidly cooling to glass frit and then pulverizing to make a fine powder of 1 to 5 μm. High purity carbonates, oxides, hydroxides and the like can be used as raw materials. Depending on the type and composition of the glass powder, high-resistance and dense pores can be obtained by using powders that are made of ultra-pure alkoxide and organometallic materials with a purity of 99.99% or more, and that are homogeneously produced by the sol-gel method. This is preferable because a high-purity dielectric layer and barrier ribs can be obtained.
[0058]
The particle size of the glass powder used in the above is selected in consideration of the thickness of the dielectric layer to be produced and the line width and height of the partition walls. The powder has a particle size of 50% by volume (average particle size, D50) is 2.0 to 6.0 μm, 10 volume% particle diameter (D10) is 0.6 to 1.7 μm, 90 volume% particle diameter (D90) is 7 to 20 μm, the top size is 45 μm or less, and the specific surface area 1.5-3.0m²/ G is preferred. Furthermore, D50 is 3.0 to 5.5 μm, D10 is 1.0 to 1.5 μm, D90 is 8.0 to 15 μm, the top size is 35 μm or less, and the specific surface area is 1.0 to 2.0 m.²/ G is more preferable.
[0059]
The amount of the glass powder in the barrier rib forming photosensitive paste is preferably 65 to 85% by weight. If it is less than 65% by weight, the shrinkage rate during firing becomes large, which causes disconnection and peeling of the partition walls, which is not preferable. Also, pattern thickening and residual film formation during development are likely to occur. When it is more than 85% by weight, the photosensitive component is too small and the pattern forming property is deteriorated.
[0060]
As the photosensitive organic component of the barrier rib photosensitive paste, it is possible to use any of the types that are solubilized by exposure and the types that are insolubilized by exposure. It is preferable to use a photo-insolubilizing type with many variations, that is, a type in which an exposed portion is photo-cured, from the viewpoints of the possibility of application, the physical properties of the formed pattern, and the improvement of the binder removal property during firing.
[0061]
The photosensitive organic component usually comprises an oligomer or polymer component, a photosensitive monomer component, and a photopolymerization initiator as basic elements, but in addition to these, a solvent, a sensitizer, and a stabilizer as necessary. Further, a plasticizer, an ultraviolet light absorber, a polymerization inhibitor and the like can be added. You may add the dispersing agent which improves the dispersion stability of an inorganic material, the leveling agent for improving applicability | paintability, etc. to the photosensitive paste.
[0062]
In order to control the refractive index of the organic component contained in the photosensitive paste, it is necessary to pay attention to the refractive index of the photosensitive monomer. By using a photosensitive monomer having a refractive index of 1.55 to 1.8, the refractive index of the organic component can be increased. The photosensitive monomer having a high refractive index is preferably an aromatic ring such as a benzene ring or a naphthalene ring, or a polyfunctional acrylate or polyfunctional methacrylate monomer containing a sulfur atom.
[0063]
The oligomer or polymer constituting the photosensitive paste can be selected from the organic binders applied to the dielectric paste described above. However, in consideration of pattern formability and development characteristics, the side chain has a carboxyl group. It is preferable to use a photosensitive and aqueous alkali-soluble component having an ethylenically unsaturated group.
[0064]
The photopolymerization initiator is selected from those that generate radical species. The use of a sensitizer is an important condition because it is necessary to form a partition pattern having a high definition and a high aspect ratio. A combination of a single molecule direct cleavage type photopolymerization initiator and a triplet sensitizer is preferred, but is not limited thereto.
[0065]
The viscosity of the photosensitive paste is adjusted by the amount of the organic solvent that dissolves the organic component. Cellosolves, acetone, methyl ethyl ketone, cyclohexanone, alcohols, tetrahydrofuran, dioxane, dimethyl sulfoxide, γ-butyrolactone and the like are used alone or in combination.
[0066]
The photosensitive paste is formed by using a known technique such as a screen printing method, a bar coater method, a roll coater method, a slit die coater method, or a blade coater method on a fired or unfired film on the uppermost layer of the dielectric layer. Applied.
[0067]
After applying the photosensitive paste, exposure is performed using an exposure apparatus. The exposure is performed through a photomask, as is done with normal photolithography techniques. At this time, either a method of closely attaching the photomask to the surface of the photosensitive paste coating film or a proximity exposure method performed at a predetermined interval may be used. The actinic ray used for the exposure is most preferably ultraviolet light, and as its light source, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a halogen lamp or the like is used. It is common to use a proximity exposure machine that uses parallel light from an ultra-high pressure mercury lamp as a light source. The exposure conditions vary depending on the coating thickness of the photosensitive paste, but 3-50 mW / cm²The exposure is performed for 10 seconds to 20 minutes using an ultra-high pressure mercury lamp of
[0068]
After the exposure, development is performed using the difference in solubility between the exposed portion and the unexposed portion in the developer. In this case, an immersion method, a spray method, a brush method, or the like is used. As the developer, a solution in which organic components in the photosensitive paste, in particular oligomers or polymers, can be dissolved is used. It is preferable in the process that aqueous alkali development is possible. By using a photosensitive paste oligomer or polymer having a carboxyl group in the side chain, alkaline aqueous solution development is possible. As the aqueous alkaline solution, an aqueous solution of sodium hydroxide, sodium carbonate, calcium hydroxide, or the like can be used. However, it is preferable to use an organic alkaline aqueous solution because an alkaline component can be easily removed during firing. A common amine compound can be used as the organic alkali. Specific examples include tetramethylammonium hydroxide, trimethylbenzylammonium hydroxide, monoethanolamine, and diethanolamine. The temperature during development is preferably 20 to 40 ° C. for process control.
[0069]
The barrier rib pattern formed from the coating film of the photosensitive paste through the process of exposure and development is baked in a baking furnace to thermally decompose and remove the organic component, and at the same time, the glass fine particle component is melted to form the inorganic barrier rib. Form. The firing atmosphere and temperature vary depending on the characteristics of the paste and the substrate, but are usually fired in air. As the firing furnace, a batch-type firing furnace or a belt-type continuous firing furnace can be used.
[0070]
In order to perform batch-type baking, the glass substrate on which the barrier rib pattern is formed is usually heated from room temperature to about 500 ° C. over several hours at a substantially constant speed, and then heated to 550 to 600 ° C. set as the baking temperature. Raise in -40 minutes, hold for 15-30 minutes and fire. Since the firing temperature must be lower than the glass transition point of the glass substrate used, there is an upper limit naturally. If the firing temperature is too high or the firing time is too long, defects such as sagging occur in the shape of the partition walls. In addition, if the thermal decomposition characteristics of the photosensitive monomer, photosensitive oligomer or polymer, and various additives contained in the organic component and the thermal characteristics of the glass powder component are disproportionate, the partition wall is colored brown or the partition wall is separated from the substrate. Defects that peel off occur.
[0071]
A member for a plasma display can be obtained by forming a phosphor layer on the side surfaces of the formed barrier ribs and on the bottom between the barrier ribs.
[0072]
The phosphor layer is, for example, a phosphor powder that emits light in any one color of red, green, and blue, and a phosphor paste of three colors mainly composed of a binder resin and a solvent, in stripes between the partition walls on the substrate. It can be formed by baking after coating. The method for applying the phosphor paste is not particularly limited, and can be performed by a screen printing method, a sand blast method, or a photolithography method, and can be applied by discharging from a die having discharge holes.
[0073]
The plasma display member of the present invention is sealed with, for example, a separately prepared front glass substrate, and then a plasma display with high brightness and no defects such as crosstalk is obtained by sealing the discharge gas and mounting the wiring. Obtainable.
[0074]
【Example】
Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these. In addition, the density | concentration in an Example is weight%, when there is no notice.
[0075]
Examples 1 to 6, Comparative Examples 1 and 2
1. Formation of electrode layer
A 125 mm square glass substrate (PD-200 manufactured by Asahi Glass Co., Ltd.) on which a striped electrode (silver content 95%) pattern having a pitch of 230 μm and a line width of 200 μm was formed using a photosensitive silver paste containing silver powder having an average particle diameter of 3 μm. ) In air at 590 ° C. for 30 minutes to form an electrode layer having a thickness of 5 μm.
[0076]
2. Dielectric layer formation
As the glass containing 10 to 70% bismuth oxide substantially free of alkali metal component for forming the dielectric layer, the dielectric paste a having the following composition and characteristics was used.
[0077]
Glass composition:
Bismuth oxide 44%, silicon oxide 13%, boron oxide 19%, aluminum oxide 1%, zinc oxide 10%, iron oxide 4%, cobalt oxide 3%, titanium oxide 2%, zirconium oxide 2%, chromium oxide 2%.
[0078]
Glass characteristics:
Average particle size 3.4 μm, glass transition point 476 ° C., softening point 515 ° C., thermal expansion coefficient α50-40075 × 10^-7/ K.
[0079]
The dielectric paste b having the following composition and characteristics was used.
Glass composition:
Bismuth oxide 38%, silicon oxide 7%, boron oxide 19%, barium oxide 12%, aluminum oxide 3%, zinc oxide 21%.
[0080]
Glass characteristics:
Average particle size 3.4 μm, glass transition point 476 ° C., softening point 525 ° C., thermal expansion coefficient α50-40077 × 10^-7/ K.
[0081]
Moreover, the filler used for the dielectric paste b is Ishihara Sangyo Co., Ltd. rutile type titania (R550), and an average particle diameter is 0.24 micrometer.
[0082]
Both the dielectric pastes a and b were prepared by dispersing and mixing the glass powder and filler component in an ethylcellulose 6% terpineol solution and then kneading the mixture with a three-roller. The proportions of glass powder, filler and organic component were 60%, 6% and 34%. By applying the dielectric layer A to the glass substrate on which the above electrode layer is formed by screen printing, drying, forming the dielectric layer B by the same method, and firing at a predetermined temperature for 30 minutes. A dielectric layer having a thickness of 20 μm was formed.
[0083]
Table 1 shows the optical density (OD value) of the dielectric layer A obtained when the thickness of the dielectric layer B is fixed to 10 μm and the thickness of the dielectric layer A is changed, and the total light reflection of the dielectric layer B. The rate is shown (Examples 1-3).
[0084]
[Table 1]

[0085]
In addition, dielectric layers A and B having the following contents were formed by the same method as in Examples 1 to 3 (Examples 4 to 6).
[0086]
Table 2 shows the optical density (OD value) of the dielectric layer A and the total light reflectance of the dielectric layer B obtained when the thickness of the dielectric layer A is fixed to 10 μm and the thickness of the dielectric layer B is changed. Shown in
[0087]
[Table 2]

[0088]
Furthermore, the dielectric layers A and B were adjusted to form dielectric layers having the OD value of the dielectric layer A and the total light reflectance of the dielectric layer B shown in Table 3 (Comparative Examples 1 and 2).
[0089]
[Table 3]

[0090]
3. Partition formation
A partition wall was formed on the dielectric layer having a multilayer structure including the dielectric layers A and B obtained in Examples 1 to 6 and Comparative Examples 1 and 2 as follows.
[0091]
32 g of 34% γ-butyrolactone solution of photosensitive polymer (X-4007), 10.5 g of photosensitive monomer (MGP400), 3.4 g of photopolymerization initiator (IC-369), sensitizer (DETX-S) 3. 4 g, UV light absorber (Sudan IV) 0.04 g, and glass component 49 g having the following composition and characteristics are mixed and pre-kneaded, and then a three-roll roll to produce a photosensitive paste.
[0092]
Glass composition:
9% lithium oxide, 20% silicon oxide, 31% boron oxide, 4% barium oxide, 24% aluminum oxide, 2% zinc oxide, 6% magnesium oxide and 4% calcium oxide.
[0093]
Glass characteristics:
Average particle size 2.6 μm, glass transition point 480 ° C., softening point 520 ° C., thermal expansion coefficient 79 × 10^-7/ K.
[0094]
The photosensitive paste was applied by repeating screen printing a plurality of times so as to have a dry thickness of 180 μm. A photomask (stripe pattern, pitch 150 μm, line width 20 μm) is placed on the coating film, and 12 mW / cm.²Exposure with an ultra high pressure mercury lamp exposure machine with a power of 0.6 J / cm²The exposure amount was given.
[0095]
Thereafter, a 0.2% aqueous solution of monoethanolamine kept at 35 ° C. was developed by showering for 120 seconds, and further washed with water. As a result, a partition wall pattern having an excellent shape was formed, and the surface of the dielectric layer was exposed in the portion where the paste coating film in the unexposed portion was removed. The partition wall pattern was baked in air at 570 ° C. for 15 minutes, and observed with an electron microscope, the partition wall height was 130 μm, and the line width (half width) was 33 μm.
[0096]
4). Phosphor formation and panel fabrication
A phosphor paste was applied by a nozzle coating method to the substrate on which the partition walls were formed on the dielectric layer obtained in 3 above, and baked to form a phosphor layer, thereby producing a back glass substrate for plasma display. A separately manufactured front glass substrate and the rear substrate were sealed, a Xe-He mixed gas was sealed in a discharge cell, and a wiring was mounted to obtain a plasma display.
[0097]
5. Evaluation
The panel discharge was evaluated visually, and the results are shown in Table 4.
[0098]
[Table 4]

[0099]
From Table 4, it can be seen that the plasma display panel obtained according to the example of the present invention is free from halation and can obtain very high luminance.
[0100]
Explanation of abbreviations
X-4007:
A side chain having a weight average molecular weight of 43,000 and an acid value of 95 is obtained by addition reaction of 0.4 equivalent of glycidyl methacrylate to a carboxyl group of a copolymer composed of 40% methacrylic acid, 30% methyl methacrylate and 30% styrene. A polymer having a carboxyl group and an ethylenically unsaturated group.
[0101]
MGP400: Compound represented by the following chemical formula
[Chemical 1]

[0102]
IC-369: Irgacure-369 (Ciba-Geigy product)
2-Benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1
DETX-S: 2,4-diethylthioxanthone
Sudan IV: UV absorber (manufactured by Tokyo Chemical Industry Co., Ltd.)
[0103]
【The invention's effect】
The member for plasma display of the present invention is a member in which at least an electrode layer, a dielectric layer A, a dielectric layer B, a partition wall and a phosphor layer are sequentially formed on a substrate, and the dielectric layer A has an optical density (OD). Value) 0.5 or more black layer, and since the dielectric layer B is a white layer having a total light reflectance of 40% or more, a high-quality plasma display member capable of preventing halation and displaying high brightness. Can be obtained.

Claims (8)

A member in which at least an electrode layer, a dielectric layer A, a dielectric layer B, a partition wall and a phosphor layer are sequentially formed on a substrate, and the dielectric layer A has a black layer having an optical density (OD value) of 0.5 or more. The member for a plasma display, wherein the dielectric layer B is a white layer having a total light reflectance of 40% or more. The member for a plasma display according to claim 1, wherein both the dielectric layer A and the dielectric layer B are substantially free of alkali metal. The member for a plasma display according to claim 2, wherein the dielectric layer A and the dielectric layer B are mainly composed of glass having a glass transition point of 400 to 550 ° C and a softening point of 400 to 600 ° C. The plasma display according to claim 3, wherein the dielectric layer A contains 50 to 98% by weight of glass having a glass transition point of 400 to 550 ° C and a softening point of 400 to 600 ° C and 2 to 50% by weight of a black pigment. Materials. The member for a plasma display according to claim 4, wherein the black pigment contains an oxide of at least one metal selected from Cr, Co, Fe, Mn, Ni, and Ru. The dielectric layer B contains 50 to 90% by weight of glass having a glass transition point of 450 to 550 ° C and a softening point of 500 to 600 ° C and 10 to 50% by weight of white filler. The member for plasma display of Claim 1. The member for a plasma display according to claim 6, wherein the white filler is at least one selected from the group consisting of titania, alumina, silica, barium titanate, and zirconia. The member for a plasma display according to claim 6 or 7, wherein the white filler has an average particle size of 0.15 to 5.00 µm.