JP2006151793A - Electron-conductive glass and spacer for electron beam-excitation type display using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electron-conductive glass having electrical characteristics having moderate electric conductivity without the occurrence of electrostatic charge and dielectric breakdown and thermal characteristics not giving rise to deformation and breakage in a heat treating step, and not containing environmental pollutants, and a spacer for electron beam-excitation type display using the same. <P>SOLUTION: The electron-conductive glass contains 30 to 70 mol% P<SB>2</SB>O<SB>5</SB>, 25 to 65 mol% transition metal oxide, ≤25 mol% RO (R is an alkaline earth metal), and ≤15 mol% R'<SB>2</SB>O (R' is an alkali metal). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to an electron conductive glass, and more particularly to a glass spacer for an electron beam excitation display that can effectively prevent charging and dielectric breakdown.

  Generally, glass is an insulator and has an extremely high electrical resistivity. However, among the glass that is an insulator, the electron conductive glass retains electrically excellent conductivity.

  Electronically conductive glass has been widely known (see glass engineering handbooks, glass handbooks, etc.). When the transition metal elements contained in the glass have two or more different valences, they are made conductive by hopping conduction. It has the characteristic of having.

A cathode ray tube (CRT) is a video device that has been widely used in the past, and is very heavy and requires depth. On the other hand, LCD (Liquid
A so-called flat panel display (FPD) such as a crystal display (PDP) or a plasma display panel (PDP) has been developed as a post-CRT tube in recent years, and is now becoming popular as a general video device.

  Among the flat panel displays mentioned above, self-luminous electron beam excitation displays typified by field emission displays (FEDs) are attracting attention as displays that can produce higher quality images. Research and development is actively underway.

  An electron beam excitation display with a flat and thin structure has a front plate (Anode substrate) made of a glass substrate formed of an image forming member such as a phosphor on the inner surface, a cathode formed of an electron-emitting device, a gate electrode, a focusing electrode, and the like. It is composed of a back plate (Cathode substrate) made of a glass substrate on which is mounted. The front plate and the back plate are combined through a support member and sealed by a low melting point frit that is a sealing member to form a vacuum-tight airtight structure.

Such an electron beam excitation display having a flat and thin structure forms an image by exciting phosphors with electrons generated and emitted by the tunnel effect. At this time, the degree of vacuum in these components is generally maintained at about 1 × 10 ⁻⁸ to 1 × 10 ⁻⁵ Pa although it depends on the type of cathode configuration.

  As the display screen size of the display increases, an atmospheric pressure due to an external atmospheric pressure difference is applied to the vacuum-sealed container, so that the front plate and the rear plate are deformed and damaged by the pressure, and the vacuum state in the container cannot be maintained. In order to prevent this and maintain the shape and interval of the front plate and the back plate constant, a spacer which is an atmospheric pressure support member made of ceramics or glass is inserted between them. The structure of such an electron beam excitation display is described in Japanese Patent Application Laid-Open No. 7-230776 and the like, and is already known.

  The spacer refers to a columnar shape that holds a partition (space) between the Cathode substrate and the Anode substrate of the electron beam excitation display. The spacer is publicly known as described in JP-T-2002-505502 and JP-A-2001-335358.

Japanese Patent Laid-Open No. 7-230776 Special table 2002-505502 JP 2001-335358

The characteristics required for spacers are that no breakdown occurs in a high vacuum state, stability against electric changes caused by electric field radiation, maintaining appropriate electrical conductivity (electric conductivity), For example, maintaining a thermal expansion coefficient equivalent to that of the member.

  Since glass and ceramics are generally insulators, when a part of the electrons irradiated from the electron beam source collide with the spacer, the electrons are caught and the spacer itself is charged. When this charging is repeated and the allowable amount of the spacer itself is exceeded, the electrons trapped in the spacer are released at a stretch, which has a large effect on the display image and causes a problem that the image cannot be displayed accurately.

  In addition, when the electrons captured by the spacer start to be charged, the electron beam emitted from the electron source is attracted to the spacer and loses straightness. As a result, there is a problem that the electron beam cannot collide with the phosphor surface and the display image cannot be displayed accurately.

  Further, when the conductivity of the spacer itself is large, electrons emitted from the electron beam source are conducted not in vacuum but through the highly conductive spacer itself, and cannot collide with the phosphor surface.

  Since a high voltage is applied in the vacuum-sealed hermetic structure of the electron beam excitation display, the spacer material itself causes dielectric breakdown due to the high voltage, greatly affecting the display image and causing a failure.

  As a technique for improving such a problem, formation of a conductive film on the spacer surface (Japanese Patent Laid-Open No. 8-180821, etc.) and a ceramic spacer mixed with an electron conductive substance (US Pat. No. 5,675,212) are known. It has become. However, such spacers have not yet reached a fundamental solution in terms of productivity, production cost, quality, etc., and because ceramic materials have numerous sintered interfaces, dielectric breakdown is likely to occur. There are also drawbacks.

Japanese Patent Laid-Open No. 8-180821 US Pat. No. 5,675,212

  Although it changes with kinds of member to be used, it is necessary for a spacer to hold | maintain the average linear thermal expansion coefficient equivalent to a glass substrate and a sealing member. Since the electron beam excitation display undergoes a heat treatment step, if the average linear thermal expansion coefficient of the spacer is not equivalent to that of the glass substrate or the sealing member, distortion occurs due to the difference in the thermal expansion coefficient, which causes destruction.

  In addition, if the heat resistance of the spacer itself is low, softening deformation occurs in the heat treatment process, so that the function as the spacer cannot be achieved, which causes destruction.

  In addition, conventionally used glass spacers contain a large amount of PbO, which is an environmental pollutant. In addition, it often contains harmful substances such as V, Cd, and Cr.

The present invention has been made in view of the situation as described above, and is capable of preventing the charging of an electron conductive glass spacer for an electron beam excitation display, and an electronic conductivity free from environmental pollutants used for the glass spacer. The object is to provide glass.
Another object of the present invention is to provide an electron conductive glass spacer for an electron beam excitation display having an appropriate electrical conductivity and an electron conductive glass containing no environmental pollutant used for the glass spacer.
Still another object of the present invention is to provide an electron conductive glass spacer for an electron beam excitation display having a characteristic of maintaining a high dielectric breakdown resistance, and an electron conductive glass free from environmental pollutants used for the glass spacer. There is to do.
Still another object of the present invention is to provide an electron conductive glass spacer for an electron beam excitation display having a high heat resistance and a property of maintaining an average linear thermal expansion coefficient that can be used in a wide range, and environmental pollution used in the glass spacer. The object is to provide an electron-conducting glass free of substances.

The electron conductive glass according to the first aspect of the present invention is composed of 30 to 70 mol% P ₂ O ₅ , 25 to 65 mol% transition metal oxide, 25 mol% or less RO (R is an alkaline earth metal) ), 15 mol% or less of R ′ ₂ O (R ′ is an alkali metal).

The electron conductive glass according to the second aspect of the present invention has an average linear thermal expansion coefficient in the range of 30 to 450 ° C. is in the range of ^{45 × 10 -7 / K~95 × 10} -7 / K And the glass transition temperature is 470 ° C. or higher.

Furthermore, the glass spacer for electron beam excitation display according to the third aspect of the present invention uses the glass according to the first aspect or the second aspect.

As a result of intensive studies to achieve the above object, the present inventor has found that the glass spacer used in the electron beam excitation display provided with the glass substrate contains 30 to 70 mol% of P ₂ O ₅ and a transition metal oxide. Consists of phosphate glass containing 25 to 65 mol%, RO (R is alkaline earth metal) 25 mol% or less, and R ' ₂ O (R' is alkali metal) 15 mol% or less As a result, it has been found that the phenomenon of electrification caused by the electrons colliding with the spacer when the electron beam is emitted from the electron beam source can be prevented.

  The present inventors have also found that the dielectric strength, which is a problem with the conventional spacer material, is high and that it does not contain environmental pollutants.

  The present invention has been made based on the results of the above research.

  First, the present invention will be described by taking an electron beam excited display glass spacer as an example. The glass composition constituting the spacer can be widely used in other fields such as the electronics field as a glass substrate or an antistatic material, and is not limited to this application.

The glass composition constituting the glass spacer for electron beam excitation display according to the present invention comprises 30 to 70 mol% of P ₂ O ₅ , 25 to 65 mol% of transition metal oxide, RO (R is an alkaline earth metal, and Is 25 mol% or less and R ′ ₂ O (R ′ is an alkali metal) and 15 mol% or less.

P ₂ O ₅ is a glass-forming oxide and is a main component that forms a glass skeleton. If P ₂ O ₅ is less than 30 mol%, it is difficult to vitrify and it tends to devitrify. Although the phosphate glass is originally low in chemical durability, when the P ₂ O ₅ content exceeds 70 mol%, the chemical durability is extremely lowered. Therefore, the P ₂ O ₅ content is 30 to 70 mol%, preferably 40 to 65 mol%.

The transition metal oxide is necessary for imparting electronic conductivity to the glass. However, it has been very difficult to contain a large amount of transition metal oxide in the conventional SiO ₂ (silicate) glass. In addition, even if transition metal oxides can be contained in B ₂ O ₃ (borate) glass, chemical durability, heat resistance, and the like are very low, so that they are not practical.

  According to the phosphate-based glass found in this study, it becomes possible to contain a large amount of transition metal oxide, which has been impossible in the past.

  In order to obtain a desired electrical conductivity, the content of the transition metal oxide is preferably 25 to 65 mol%. Since there is a balance with introduction of other components, it is preferably 35 to 50 mol%. When the content of the transition metal oxide is less than 25 mol%, charging occurs on the spacer, and the desired electronic conductivity cannot be maintained. For this reason, the function as a glass spacer for electron beam excitation type displays cannot be performed. On the other hand, when the content of the transition metal oxide exceeds 65 mol%, the glass is devitrified and a stable glass cannot be obtained.

  Transition metal ions can have different valence states in the glass. Further, it is generally well known that the valence of transition metal ions in glass changes depending on the glass composition, melting temperature, melting atmosphere, and the like.

It is known that the electron conductive glass has conductivity because the transition metal ions contained in the glass exist at different valences, so that electrons can be exchanged. In general, the greater the content of the transition metal element contained in the glass, the greater the conductivity. In the present invention, not a conventional SiO ₂ type or B ₂ O ₃ type, but a phosphate type glass composition that can contain a large amount of transition metal oxides has been found, so that a very good conductivity can be maintained. Things became possible.

  The transition metal oxide is preferably selected from W, Fe, Cu, Co, Ni, Mo, Mn, Sn, Ti, and is used according to the required characteristic value of the conductivity of the electron beam excited display spacer. It is desirable to adjust the transition metal oxide and content.

  Since each transition metal element has a different activation energy for electron conductivity, the electron conductivity is also different. According to the study of the present inventor, Fe, Mn, and Cu are preferable because they retain an appropriate activation energy in glass, and W is particularly preferable.

  Alkaline earth metal oxides RO (MgO, CaO, SrO, BaO) improve the average linear thermal expansion coefficient of the glass and also improve the chemical durability of the glass. One or more types of RO are contained, and are used for adjusting the viscosity and devitrification temperature of glass. If the alkaline earth metal oxide RO exceeds 25 mol%, the heat resistance of the glass is excessively lowered. It is also possible to have a composition that does not contain any alkaline earth metal oxide RO.

When mobile ions such as alkali metal oxides R ′ ₂ O (Li ₂ O, Na ₂ O, K ₂ O, Rb ₂ O) are present in the glass forming the glass spacer as in the present invention, the bias voltage In the end, segregation eventually occurs, resulting in local distribution of conductivity. This causes dielectric breakdown and charging problems. In order to avoid such a phenomenon, it is desirable to reduce the R ′ ₂ O content as much as possible. Even if contained, it is desirable to select an alkali metal oxide that is a heavy element as much as possible. Alternatively, it is effective to contain two or more types of R ′ ₂ O and reduce the mobility of ions due to the mixed alkali effect. The content of the alkali metal oxide R ′ ₂ O is preferably as small as possible. However, since it greatly contributes to the average linear thermal expansion coefficient and the solubility of the glass, it is set in consideration of this point. Specifically, the content is 15 mol% or less. It is also possible to have a composition that does not contain any alkali metal oxide R ′ ₂ O.

Further, in order to improve chemical durability and heat resistance, the total of one or more of Al ₂ O ₃ , ZnO, Nb ₂ O ₅ , Ta ₂ O ₅ , Bi ₂ O ₃ is 20 It is desirable to contain it so that it may become less than mol%.

  It is not preferable that the spacer glass for an electron beam excitation display contains an environmental pollutant or a highly toxic compound. Therefore, the glass material of the present invention includes an embodiment that does not contain V, Pb, As, Sb, Cr, and Cd.

If the electrical resistance of the glass spacer is too low due to the structure of the electron beam excitation display, it becomes a conduction path for electrons emitted from the electron source, which may be an electrical obstacle. In addition, when the electrical resistance of the glass spacer is too high, charge accumulation occurs, resulting in various problems due to charging. Therefore, it is desirable that the resistivity of the glass spacer for an electron beam excitation display of the present invention is approximately 1 × 10 ⁶ to 1 × 10 ¹² ohms · cm.

It is desirable that the average linear thermal expansion coefficient of each glass substrate and sealing member of the electron beam excitation display described above and that of the electron conductive glass spacer match. In the electron beam excitation display, since a high strain point glass for a plasma display panel or the like is used as a substrate, it is desirable that the glass spacer also has a thermal expansion coefficient equivalent to these, and its value is approximately 45 to 95. × 10 ^-7 / K.

In addition, by introducing the above-described components into the main component P ₂ O ₅ , the electron conductive glass in the present invention can maintain heat resistance that does not cause softening deformation even after a heat treatment step. The value is about 470 ° C. or more at the glass transition point.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples.

The base glass of the glass material according to the present invention was adjusted as follows. Orthophosphoric acid which is a special grade reagent as P ₂ O ₅ raw material, desired transition metal oxide as transition metal oxide raw material, RO (where R is alkaline earth metal) raw material and R ′ ₂ O (where R ′ is alkaline) (Metal) Carbonate of each metal element was used as a raw material. These raw materials were mixed at a predetermined ratio, and the batch weight was 700 g. This raw material mixture was put in an alumina crucible, covered with an alumina lid for suppressing volatilization of the raw material during melting, and melted in an electric furnace maintained at 1100 ° C. to 1400 ° C. for 0.5 to 1 hour. After melting, the glass was poured into a surface-treated mold, slowly cooled at a temperature of 500 to 650 ° C. for 2 hours, and naturally cooled to obtain a glass sample. The vitrification state and electronic conductivity of the obtained glass sample were confirmed. Further, it was confirmed whether the volume resistivity, the average linear thermal expansion coefficient, and the glass transition point were within the desired characteristic range. Examples of the results are shown in Tables 1 and 2. The numerical values of the glass compositions described in Tables 1 and 2 are all expressed in mol%.

In Tables 1 and 2, vitrification indicates that the glass is stably obtained by melting by the above method, and vitrification indicates that the raw material mixture does not completely dissolve or the glass solution It means that crystals were precipitated during the cooling process and a stable glass could not be obtained.

  The electronic conductivity of glass can be identified by the change in electrical resistance over time. In general glass exhibiting normal ion conductivity, uneven distribution (segregation) of ions occurs due to continuous application of a DC voltage, and as a result, electric resistance gradually increases. However, the above change does not occur in the electron conductive glass. This is already widely known (see, for example, J.D. Mackenzie, Modern Aspects of the Vitreous States, Vol. 3). In the present invention, when there was no change in the measured value immediately after the measurement of electric resistance and after 4 hours, it was determined that the electron conductivity was exhibited. In Tables 1 and 2, the electron conductivity is ◯, as described above, that there is no change in the measured value immediately after the measurement of the electrical resistance and the measured value after 4 hours, and the electron conductivity is x. Means that there was a change between both measurements.

The electrical resistance of the glass is about 3 mm on both sides polished, and the measuring method is JIS-C
According to 2141. In Tables 1 and 2, the volume resistivity is within the desired range (the volume resistivity at 25 ° C. is in the range of 1.0 × 10 ^{6 to} 1.0 × 10 ¹² ohms · cm). As evaluated.

The average linear thermal expansion coefficient and the glass transition point of the glass were measured in accordance with JIS-R 3102. In Table 1 and Table 2, average coefficient of linear thermal expansion and the glass transition temperature, within a range within the desired range (average linear thermal expansion coefficient of ^{45 × 10 -7 / K~95 × 10} -7 / K, the glass transition The case where the temperature was 470 ° C. or higher was evaluated as “◯”, and the case outside the range was evaluated as “X”.

  The obtained glass material can be processed into various shapes by machining such as cutting, cutting and polishing, or stretching such as welding. In this example, a glass spacer having a predetermined shape was processed. The processing shape of these spacers is already known, and for example, a sheet-like shape or a cylindrical shape is known (eg, seminar organized by the Information Organization, AC040714).

  Using a glass material processed into a spacer shape, we prototyped a 5-inch size electron beam-excited display and operated it to confirm that there was no abnormality.

  As is apparent from Tables 1 and 2, the present invention can supply an electron conductive glass having excellent stability and characteristics within the scope of the present invention. It is possible to supply a suitable glass spacer.

Table 3 shows the glass of the comparative example and its characteristics. The numbers of the glass compositions in Table 3 are all mol%, and each evaluation item is the same as in the example.

  In Table 3, Comparative Example 1 is a representative example of commercially available glass. Although a very stable glass was obtained, it did not exhibit electronic conductivity and exhibited a very high volume resistivity.

In Comparative Example 2, since the content of P ₂ O ₅ that is a network-forming oxide of glass was small and the content of transition metal oxide was large, a stable glass could not be obtained.

In Comparative Example 3, glass is stably obtained and also exhibits electronic conductivity. However, since RO exceeds 25 mol%, the average linear thermal expansion coefficient exceeds 95 × 10 ⁻⁷ / K. The transition temperature was also less than 470 ° C., and when used as a spacer, breakage occurred due to the effect of thermal strain.

In Comparative Example 4, a glass can be obtained stably, but since the change in the electric resistance value immediately after the start of measurement and after 4 hours was observed, the electron conductivity was not good (×), and R ′ ₂ O was reduced to 15 mol%. As a result, the average linear thermal expansion coefficient exceeded 95 × 10 ⁻⁷ / K and the glass transition temperature was less than 470 ° C. When used as a spacer, damage was caused by the influence of thermal strain.

  In Comparative Examples 5 and 6, glass can be obtained stably, but due to the low content of transition metal oxides, sufficient electronic conductivity was not exhibited.

As explained in detail above, according to the electron conducting glass according to the present invention, 30 to 70 mol% P ₂ O ₅ , 25 to 65 mol% transition metal oxide, 25 mol% or less RO ( R is an alkaline earth metal) and is composed of a glass composition containing 15 mol% or less of R ′ ₂ O (R ′ is an alkali metal). Glass spacers that can be effectively prevented can be supplied.

  Further, since the transition metal oxide is an oxide of at least one metal element selected from the group consisting of W, Fe, Cu, Co, Ni, Mo, Mn, Sn, and Ti, Thus, vitrification is possible, and a glass spacer having practical electronic conductivity can be obtained.

  In addition, it is characterized by not containing V, Pb, As, Sb, Cr, and Cd, which are recognized as hazardous substances, so it is possible to obtain glass spacers that comply with environmental impacts and environmental regulations unlike conventional materials. .

Further, since the volume resistivity at 25 ° C. is in the range of 1.0 × 10 ^{6 to} 1.0 × 10 ¹² ohms · cm, a glass spacer that retains the conductivity necessary for the electron beam excited display spacer. Can supply.

Moreover, said the in the range of average linear thermal expansion coefficient of ^{45 × 10 -7 / K~95 × 10} -7 / K in the range thirty to four hundred and fifty ° C., and a glass transition temperature of 470 ° C. or higher Therefore, softening deformation does not occur in the heat treatment process with the components of the electron beam excitation display, and since the same average linear thermal expansion coefficient is maintained, it is possible to prevent deformation and destruction due to the thermal expansion difference in the heat treatment process. Glass spacers can be supplied.

  Moreover, according to the glass spacer for electron beam excitation type | mold displays produced with the electron conductive glass by this invention, the glass spacer for electron beam excitation type | mold displays which overcome the problem mentioned above can be supplied.

  As described above, the present invention has been described by taking the glass spacer for electron beam excitation display as an example, but the present invention is not limited to these examples, and can be applied to various other uses. For example, it can be widely used in the electronics field etc. as various glass substrates for antistatic materials, conductive frit, conductive materials, semiconductors and the like.

  FIG. 1 is a cross-sectional view showing a schematic configuration of an electron beam excitation display to which a glass spacer according to the present invention can be applied. Here, a sheet-like spacer is illustrated. The flat-type electron beam excitation display includes a front plate 10 made of a glass substrate having an image forming member formed on the inner surface, and a back plate 20 made of a glass substrate on which an electron beam emitting element group is mounted. An image forming member (not shown) has a phosphor that emits light when irradiated with an electron beam from an electron-emitting device.

The glass substrate forming the front plate 10 and the back plate 20 is made of, for example, soda lime glass, high strain point glass for PDP or aluminoborosilicate glass for TFT, and the linear thermal expansion coefficient of this glass is generally 35 to 95 × 10. The range is ^-7 / K.

  The front plate 10 and the back plate 20 are airtightly joined via the support frame 30 to form a vacuum container that forms an airtight atmospheric pressure resistant structure together with the support frame 30. A plurality of glass spacers 40 according to the present invention as an atmospheric pressure support member are inserted between the front plate 10 and the back plate 20. Each glass spacer 40 has a lower end and / or an upper end fixed by an adhesive member.

  The thickness of the glass spacer 40 can be set to 0.03 to 0.30 mm, for example. Moreover, height can be 0.7-5.0 mm. In addition, the shape of the glass spacer 40 is optimally set according to the size of the display, its manufacturing method, and the like.

FIG. 1 is a cross-sectional view showing a schematic configuration of an electron beam excitation display to which a glass spacer according to the present invention can be applied.

Claims (13)

30-70 mol% P ₂ O ₅ , 25-65 mol% transition metal oxide, 25 mol% or less RO (R is an alkaline earth metal), 15 mol% or less R ′ ₂ O (R ′ is Electronically conductive glass containing an alkali metal).   The transition metal oxide is an oxide of at least one metal element selected from the group consisting of W, Fe, Cu, Co, Ni, Mo, Mn, Sn, Ti, Item 2. The electron conductive glass according to Item 1.   2. The electron conductive glass according to claim 1, wherein the RO is an oxide of at least one alkaline earth metal element selected from the group consisting of Mg, Ca, Sr, and Ba. _2. The electron conductive glass according to claim 1, wherein the R ′ ₂ O is an oxide of at least one alkali metal element selected from the group consisting of Li, Na, K, and Rb. . Any one of Al ₂ O ₃ , ZnO, Nb ₂ O ₅ , Ta ₂ O ₅ , Bi ₂ O ₃ , or a total of two or more is contained so that the total is 20 mol% or less. The electron conductive glass according to claim 1.   2. The electron conductive glass according to claim 1, which does not contain V, Pb, As, Sb, Cr, or Cd. 2. The electron conductive glass according to claim 1, wherein the volume resistivity at 25 ° C. is in the range of 1.0 × 10 ^{6 to} 1.0 × 10 ¹² ohms · cm. The average linear thermal expansion coefficient in the range of thirty to four hundred fifty ° C. is in the range of ^{45 × 10 -7 / K~95 × 10} -7 / K, and wherein the glass transition temperature of 470 ° C. or higher, The electron conductive glass according to claim 1. The average linear thermal expansion coefficient in the range of thirty to four hundred fifty ° C. is in the range of ^{45 × 10 -7 / K~95 × 10} -7 / K, electrons having a glass transition temperature and is characterized in that at 470 ° C. or higher Conductive glass. 30-70 mol% P ₂ O ₅ , 25-65 mol% transition metal oxide, 25 mol% or less RO (R is an alkaline earth metal), 15 mol% or less R ′ ₂ O (R ′ is Contains alkali metals)
The volume resistivity at 25 ° C. is in the range of 1.0 × 10 ^{6 to} 1.0 × 10 ¹² ohms · cm,
The average linear thermal expansion coefficient in the range of thirty to four hundred fifty ° C. is in the range of ^{45 × 10 -7 / K~95 × 10} -7 / K,
An electron conductive glass characterized by having a glass transition temperature of 470 ° C. or higher.   A glass spacer for an electron beam excitation display, which is made of the electron conductive glass according to claim 1.   A glass spacer for an electron beam excitation display, which is made of the electron conductive glass according to claim 9.   A glass spacer for an electron beam excitation display, which is made of the electron conductive glass according to claim 10.

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