JP5146896B2 - Manufacturing method of glass spacer for flat panel display - Google Patents

Description

  The present invention relates to a glass spacer for a flat display device, and more particularly to a glass spacer for a flat display device suitable as a spacer of a field emission display (FED).

  As a method of holding two substrates at a constant interval, a method of interposing a glass spacer between the substrates is known. This type of technology is particularly important when manufacturing a flat display device, for example, an FED, which holds two glass substrates facing each other in parallel at a constant interval. FED can use the technology cultivated in cathode ray tubes (CRT) and consumes less power than liquid crystal displays (LCDs) and plasma displays (Plasma Display Panels, PDPs). The display device is expected as a next-generation flat display device.

  As shown in FIG. 1, the FED includes a front plate 8 having a phosphor 7 that emits light when irradiated with an electron beam, and a back plate 3 on which many elements 5 that emit electrons are formed. It has a structure hermetically sealed with a cured resin. The space inside the device formed by the front plate 8 and the back plate 3 is evacuated to enable electron irradiation. Therefore, in the FED, it is necessary to prevent the front plate 8 and the back plate 3 from coming into contact with each other due to atmospheric pressure. To prevent this, a large number of glass spacers 1 are provided between the substrates to keep the interval. It has been broken.

The spacer used for this type of application is required to have high dimensional accuracy and not to be damaged or deformed by heat treatment in the manufacturing process of the display device.
JP-A-7-144939

  Patent Document 1 describes a method for manufacturing a glass spacer with high dimensional accuracy. In this method, a preformed material glass is supplied to a heating furnace at a constant speed, heated to a temperature at which it can be softened, and stretched by applying a tensile force to the softened material glass. According to this method, a spacer having a cross-sectional shape similar to the cross-section of the material glass can be produced with high accuracy. Moreover, since it can be produced continuously, mass production is possible.

  However, the glass spacer produced by stretch molding is easily damaged in the heat treatment process at the time of producing the display device. Moreover, the dimensional accuracy as designed may not be obtained.

  An object of the present invention is to provide a method of manufacturing a glass spacer that has high dimensional accuracy and is not damaged or deformed in a heat treatment process in the manufacturing process of a flat display device.

  A second object of the present invention is to provide a glass spacer that has high dimensional accuracy and is not damaged or deformed in a heat treatment process in the manufacturing process of a flat display device.

  As a result of investigation by the present inventors, the stretched glass has a high fictive temperature and is likely to cause volume shrinkage called heat shrinkage, so that the stretched glass spacer is likely to cause volume shrinkage in the subsequent heat treatment. It has been found. For example, in the FED, the glass spacer is bonded and fixed to the substrate, and it is considered that when the spacer undergoes volume shrinkage due to heat treatment, stress is generated and is damaged.

  Moreover, when glass with poor devitrification properties is employed, devitrification crystals generated during the molding of the material glass reduce the accuracy of stretch molding. Therefore, when the portion including the devitrified crystal is discarded, the manufacturing cost increases.

  Based on the above findings, the present inventors have proposed the present invention.

That is, the method for producing a glass spacer for a flat panel display device according to the present invention contains, by mass percentage, SiO ₂ 50-60%, Al ₂ O ₃ 0-7.5%, ZrO ₂ 4.4-10%, and strain point. Has a characteristic of a thermal expansion coefficient of 82 to 88 × 10 ⁻⁷ / ° C. at a temperature of 550 ° C. or higher, a liquidus temperature of 1150 ° C. or lower , and a temperature of 30 to 380 ° C., and is prepared by a float method. A step, a step of preparing a strip-shaped glass prepared by cutting the material glass, a step of stretching the strip-shaped glass under a condition that a devitrifying crystal having a major axis of 1 μm or more does not precipitate in the glass, and And a step of cutting the glass molded body.

  The material glass is made of glass having a strain point of 550 ° C. or higher. The higher the strain point, the higher the temperature at which volume shrinkage occurs. That is, the temperature range where the volume does not shrink even when heat treatment is performed becomes wide. This means that there is less risk of breakage and the like for glass spacers formed by stretch molding. Therefore, the higher the strain point of the glass, the better.

The material glass is made of glass having a liquidus temperature of 1150 ° C. or lower. As the liquidus temperature is lower, devitrification crystals are less likely to occur at the time of forming the material glass, particularly at the time of forming the plate glass. That is, the possibility that the accuracy of stretch molding is lowered due to the presence of the devitrified crystal is reduced. Moreover, if the part containing a devitrification crystal | crystallization reduces, the amount of material glass to discard can also be decreased. Therefore, the liquid phase temperature is preferably as low as possible, and is preferably 1130 ° C. or lower, 1100 ° C. or lower, particularly 1050 ° C. or lower. Further, the higher the viscosity of the glass at the liquidus temperature, the easier it is to form, so that it is preferable. 10 ^4.0 dPa · s or more, 10 ^4.3 dPa · s or more, 10 ^4.5 dPa · s or more, 10 ^4.7 dPa · s or more, It is desirable that it is 10 ^5.0 dPa · s or more.

The material glass is preferably made of glass that hardly causes devitrification crystals during stretch molding. Such glass has the characteristics defined by the following evaluation method. In this method, first, a glass having an optically polished surface is placed in a heat treatment furnace set at a temperature corresponding to a viscosity of 10 ^6.5 dPa · s in the air and held for 1 hour. Thereafter, the sample is taken out from the heat treatment furnace and naturally cooled to room temperature, and then the number of devitrified crystals having a major axis of 1 μm or more deposited on the glass surface is counted with an optical microscope. In this evaluation, if the number of devitrified crystals is 100 / mm ² or less, it can be predicted that devitrified crystals are hardly generated even if stretch molding is performed, and is preferable as a material glass used in the method of the present invention. It can be said.

The material glass preferably has a thermal expansion coefficient compatible with the substrate material of the flat display device. This is because if the thermal expansion coefficient is not suitable, the spacer is easily damaged by the stress generated by the heat treatment at the time of manufacturing the display device . When the thermal expansion coefficient of the substrate material is 85 × 10 ⁻⁷ / ° C. in the temperature range of 30 to 380 ° C., the suitable thermal expansion coefficient of the material glass is 82 to 88 × 10 ⁻⁷ / ° C.

The glass satisfying the various characteristics described above is in a mass percentage of SiO ₂ 50 to 60%, Al ₂ O _{3 0 to} 7.5%, ZrO ₂ 4.4 to 10%, particularly SiO _{2 in} mass percentage. _{50~ 60%, Al 2 O 3} 0~ 7.5%, 0~10% MgO, CaO 0~12%, BaO 0~12%, SrO 0~15%, MgO + CaO + SrO + BaO 10~30%, ZrO 2 4. It can be produced within a composition range of 4 to 10%, Na ₂ O 0 to 15%, and K ₂ O 0 to 15%. The reason for determining the composition range in this way will be described below. In the following description, “%” means “mass%” unless otherwise specified.

The content of SiO ₂ is 50 to 60 %. When the content of SiO ₂ is increased, melting of the glass, molding may become difficult, it is limited to 6 0% or less to or becomes difficult to take the matching with the surrounding material the thermal expansion coefficient becomes too small. On the other hand, when the content is reduced, the thermal expansion coefficient is increased and the thermal shock resistance of the glass is lowered. Therefore, the content is desirably 50% or more and 52% or more.

Al ₂ O ₃ has the effect of increasing the strain point, and is preferably contained at 0.1% or more, particularly 0.5% or more. However, when the content is increased, devitrified crystals are likely to precipitate on the glass surface, the high-temperature viscosity of the glass is increased, and melting and molding are difficult. The 7 become difficult to take matching with the surrounding material of thermal expansion coefficient is decreased. Limited to 5% or less.

  MgO is a component that lowers the high-temperature viscosity of the glass without lowering the strain point and improves the meltability and formability, and is preferably contained at 0.1% or more, particularly 0.5% or more. However, if the content of MgO increases, the glass tends to be devitrified and the coefficient of thermal expansion tends to increase. Therefore, it is limited to 10% or less, 8.5% or less, and further 5% or less. desirable.

  CaO is a component that lowers the high-temperature viscosity of the glass without lowering the strain point and improves the meltability and formability, and is preferably contained at 0.1% or more, particularly 0.5% or more. However, if the CaO content increases, the glass tends to devitrify and the thermal expansion coefficient tends to increase, so it is limited to 12% or less, 9% or less, 5% or less, and further 3% or less. It is desirable to do.

  SrO is a component that lowers the high-temperature viscosity of the glass without lowering the strain point and improves the meltability and formability, and is preferably contained at 0.1% or more, particularly 0.5% or more. However, if the SrO content increases, the glass tends to devitrify and the thermal expansion coefficient tends to increase. Therefore, it is desirable to limit it to 15% or less, 11% or less, and further 10% or less.

  BaO is a component that lowers the high-temperature viscosity of the glass without lowering the strain point and improves the meltability and formability, and is preferably contained at 0.05% or more, particularly 0.1% or more. However, if the content of BaO increases, the glass tends to be devitrified and the thermal expansion coefficient tends to increase. Therefore, it is desirable to limit it to 12% or less, 10% or less, and further 9% or less. .

  The total amount of MgO + CaO + SrO + BaO is 10-30%. When the total amount of MgO + CaO + SrO + BaO increases, the glass tends to be devitrified and the thermal expansion coefficient tends to increase. Therefore, the total amount is preferably 30% or less, 28% or less, or 25% or less. Also, the total amount of MgO + CaO + SrO + BaO If the amount is small, the strain point is likely to be lowered.

Na ₂ O is a component that lowers the high-temperature viscosity of the glass and improves the meltability and moldability. Moreover, it is also a component which adjusts the thermal expansion coefficient of glass, and it is preferable to make it contain 1% or more, especially 1.5% or more. When the content of Na ₂ O increases, the glass tends to be devitrified, and the thermal expansion coefficient becomes too large, which reduces the thermal shock resistance of the glass or makes it difficult to match the thermal expansion coefficient of the surrounding materials. . Further, since the strain point also tends to decrease, it is preferable to limit it to 15% or less, 12% or less, 9% or less, 7% or less, and further 5% or less.

K ₂ O is a component that lowers the high temperature viscosity of the glass and improves the meltability and moldability. Moreover, it is also a component which adjusts the thermal expansion coefficient of glass, and it is preferable to make it contain 0.1% or more, 0.5% or more, 3% or more, especially 4% or more. When the content of K ₂ O increases, the glass tends to devitrify, the thermal expansion coefficient becomes too large, the thermal shock resistance of the glass decreases, and it becomes difficult to match the thermal expansion coefficient of the surrounding materials. To do. Further, since the strain point tends to decrease, it is preferable to limit the strain point to 15% or less, 12% or less, 9% or less, and further 8% or less.

ZrO ₂ is a component that increases the strain point. If the content of ZrO ₂ increases, devitrification will tend to occur and molding becomes difficult. Therefore, it is preferable to limit it to 10% or less, 8% or less, and further 7% or less. On the other hand, in order to further improve the heat resistance, it is preferable to contain 4.4% or more , and more than 4.5%.

In addition to this, it is possible to add other components as long as the properties of the glass are not impaired. For example as a fining agent _{SO 3, Sb 2 O 3,} Sb 2 O 5, and selected from the group of SnO ₂ 1 or two or more may be contained 0-3%. Expensive elements such as La ₂ O ₃ , Y ₂ O ₃ , and Nb ₂ O ₅ are 5% or less, preferably 4% or less, more preferably 3% or less, and even more preferably 1% or less from the viewpoint of inexpensive production. Most preferably, it should be limited to 0.2% or less. In addition, coloring elements such as Fe ₂ O ₃ lower the infrared transmittance of the glass and prevent the temperature of the fabric from being increased by infrared rays at the time of melting. Therefore, the fabric temperature is difficult to increase and affects the foam quality. Should be limited to 1% or less, more preferably 0.5% or less. A preferable infrared transmittance at 1100 nm is 60% or more, more preferably 70% or more, and further preferably 75% or more when the plate thickness is 2.8 mm.

The glass sheet for use in the production of material glass is thus the float process, Ru der those molded directly plate from the molten glass. Furthermore, when the handling property of the strip-shaped glass is taken into consideration, it is more advantageous to use a slightly thick plate glass of about 1.5 to 8 mm, 1.8 to 6 mm, or 2.5 to 6 mm. From this point of view, it is desirable to employ float forming suitable for forming a relatively thick plate glass as a plate glass forming method. Moreover, the plate glass produced by the float process has high surface quality, and can be used for producing strip-shaped glass without polishing the surface.

  The strip-shaped glass that can be used as the material glass is produced by cutting a plate glass. If the surface quality of the plate glass is sufficiently good, it is preferable to perform cutting without polishing the plate glass surface. Note that the cut surface or the ridge line portion adjacent to the cut surface may be subjected to treatment such as polishing in order to prevent chipping and cracking and improve dimensional accuracy.

  The glass spacer is produced by stretching a material glass. When using strip glass as raw material glass, if the surface quality is sufficiently good, it is preferable to subject it to stretch molding without polishing the strip glass surface.

Stretch molding of the material glass is performed by continuously pulling out the other end of the glass while heating the material glass with one end fixed to a temperature at which stretching is possible. By the way, when glass is reheated, devitrified crystals tend to precipitate. In stretch molding, if crystals are deposited on the glass surface during molding, the glass cannot be stretched and cannot be molded at all, breaks during stretching, cracks due to the difference in thermal expansion between the devitrified crystal and glass, and the presence of devitrified crystals. The problem that dimensional accuracy falls arises. Therefore, it is important that the devitrification crystal (specifically, the devitrification crystal having a major axis of 1 μm or more) is stretch-molded under the condition that it does not precipitate in the glass, particularly on the glass surface. In order not to precipitate the devitrified crystal, the heating temperature, the heating time, the heating atmosphere, and the like suitable for the composition and size of the strip-shaped glass may be adjusted. Among these conditions, the heating temperature and the heating time are important factors. That is, when the heating temperature is lowered, it takes time until the glass becomes stretchable, and when the heating time is lengthened, devitrified crystals are likely to be deposited on the glass surface. In addition, it is necessary to spend enough time to send the glass into the heating furnace so that the glass can be stretched. Therefore, it is necessary to slow down the stretching speed, and high productivity cannot be expected. Means. On the other hand, when the heating temperature increases, the dimensional accuracy tends to decrease. A suitable heating temperature is a temperature at which the glass exhibits a viscosity of 10 ^5.5 dPa · s to 10 ^7.5 dPa · s.

  A flat display device spacer can be obtained by cutting the stretched glass molded body into a predetermined length. The cut surface or the ridge line portion adjacent to the cut surface may be subjected to processing such as polishing and etching in order to prevent chipping and cracking. In the case of FED applications, it is preferable to adjust the surface resistance by applying a conductive film to the spacer surface for the purpose of preventing spacer charging and distortion of the electron trajectory. For film formation, methods such as dipping, spraying, sputtering, and CVD can be employed. In addition, although formation of an electrically conductive film may be performed by the independent process after extending | stretching shaping | molding, it does not interfere with extending | stretching simultaneously.

  The glass spacer produced in this way is used as it is by adhering and fixing to the substrate as it is. However, for example, it may be used after combining it with other members to form a cross-girder shape etc. in order to improve self-supporting properties. .

The glass spacer for a flat display device of the present invention, by mass _{percentage, SiO 2 50~60%, Al 2} O 3 0~7.5%, ZrO 2 containing 4.4 to 10%, the strain point is 550 ° C. As described above, a glass spacer for a flat panel display device, which is made of glass having a liquid phase temperature of 1150 ° C. or less and obtained through a step of stretch-molding the material glass under the condition that a devitrified crystal having a major axis of 1 μm or more does not precipitate in the glass. The difference between the maximum height h _max and the minimum height h _min of the glass spacer is the average height h _ave when the dimension perpendicular to the substrate plane of the flat display device is the height h of the glass spacer. The value is 10% or less.

  The glass constituting the glass spacer is a glass having a strain point of 550 ° C. or higher. If the spacer is made of glass having a high strain point, the temperature at which thermal shrinkage occurs is high, so that damage or the like in a thermal process such as during FED manufacturing is less likely to occur. In particular, in the case of a spacer produced by stretch molding, since the thermal shrinkage rate is large, a high strain point is very advantageous. The higher the strain point of the glass constituting the spacer, the better, and it is desirable that it is 570 ° C. or higher and 580 ° C. or higher.

The glass constituting the glass spacer is a glass having a liquidus temperature of 1150 ° C. or lower. The lower the liquidus temperature, the easier it is to mold the material glass into a predetermined shape. Further, devitrification crystals are less likely to occur during molding. Particularly for spacers produced by stretch molding, it is desirable that devitrification crystals do not exist in the material glass. That is, if devitrified crystals exist in the material glass, it becomes difficult to obtain a spacer with high dimensional accuracy by stretch molding. Therefore, the liquid phase temperature is preferably as low as possible, and is preferably 1130 ° C. or lower, 1100 ° C. or lower, particularly 1050 ° C. or lower. Further, the higher the viscosity of the glass at the liquidus temperature, the easier it is to form the material glass, which is advantageous. 10 ^4.0 dPa · s or more, 10 ^4.3 dPa · s or more, 10 ^4.5 dPa · s or more, 10 ^4.7 dPa · s or more It is desirable that it is s or more, more preferably 10 ^5.0 dPa · s or more.

As shown in FIG. 2, the glass spacer has a maximum height h _max and a minimum height h _min when the dimension perpendicular to the substrate plane of the flat display device is the height h of the glass spacer. Is a value of 10% or less of the average height h _ave . If this value is small, it means that the dimensional accuracy in the height direction of the spacer is high. The difference between the maximum height h _max and the minimum height h _min of the spacer is 5% or less, 1% or less, 0.5%, 0.1% or less, especially 0.05% or less of the average height h _ave. It is preferable. In order to obtain a spacer with high dimensional accuracy, as described above, it is preferable to use a material glass that does not contain a devitrified crystal and to stretch-mold under conditions that do not cause the devitrified crystal. It is also important to prepare the material glass with high accuracy. The “maximum height h _max ”, “minimum height h _min ”, and “average height h _ave ” of the spacer in the present invention are defined as follows. When the dimension parallel to the substrate plane of the flat display device is the length l of the glass spacer, the heights h ₁ , h ₂ at each point (including both ends) obtained by dividing the length l into 10 equal parts, ··· h ₁₁ to measure. Among them, the maximum one is defined as the maximum height h _max , the minimum one is defined as the minimum height h _min , and the average value of h ₁ to h ₁₁ is defined as the average height h _ave .

Moreover, it is preferable that the glass spacer is made of glass that hardly causes devitrification crystals when reheated. Particularly for spacers produced by stretch molding, it is desirable that devitrification crystals do not occur in the glass by heating during stretch molding. That is, when devitrification crystals are generated during molding, it becomes difficult to obtain a spacer with high dimensional accuracy by stretch molding with a high yield. The ease with which devitrified crystals are generated can be determined by the following evaluation. First, glass having an optically polished surface is placed in a heat treatment furnace set at a temperature corresponding to a viscosity of 10 ^6.5 dPa · s in the atmosphere and held for 1 hour. Thereafter, the sample is taken out from the heat treatment furnace and naturally cooled to room temperature, and then the number of devitrified crystals having a major axis of 1 μm or more is counted with an optical microscope. If the number of devitrified crystals having a major axis of 1 μm or more deposited on the glass surface at this time is 100 pieces / mm ² or less, it can be determined that devitrified crystals are unlikely to form. Preferably it is 50 pieces / mm ² or less, 10 pieces / mm ² or less, and further 1 piece / mm ² or less, but ideally there is no devitrification crystal.

The glass spacer is preferably made of glass having a thermal expansion coefficient compatible with the substrate material of the flat display device. This is because if the thermal expansion coefficient is not suitable, the spacer is easily damaged by the stress generated by the heat treatment at the time of manufacturing the display device. For example, when the thermal expansion coefficient of the substrate material is 85 × 10 −7 / ° C. in the temperature range of 30 to 380 ° C., suitable thermal expansion coefficients of the raw glass are 50 to 95 × 10 ⁻⁷ / ° C. and 60 to 95 ×. ^{10 -7 / ℃, 70~95 × 10} -7 / ℃, 75~95 × 10 -7 / ℃, even at 82~88 × 10 ^-7 / ℃.

  The glass spacer preferably has no devitrified crystal in the glass. A glass spacer having a devitrified crystal in glass may be cracked during heat treatment due to a difference in thermal expansion between the glass phase and the devitrified crystal phase. The devitrified crystal refers to a crystal having a major axis of 1 μm or more.

The glass spacers satisfying the various characteristics described above are in mass percentages, within the composition range of SiO ₂ 50-60%, Al ₂ O ₃ 0-7.5%, ZrO ₂ 4.4-10%, especially in mass percentage. _{SiO 2 50~ 60%, Al 2} O 3 0~ 7.5%, 0~10% MgO, CaO 0~12%, BaO 0~12%, SrO 0~15%, MgO + CaO + SrO + BaO 10~30%, ZrO 2 4.4 to 10%, Na ₂ O 0 to 15%, K ₂ O 0 to 15% can be produced with glass in the composition range. The reason for determining the composition range in this way is as described above.

The glass spacer for a flat display device of the present invention, by mass _{percentage, SiO 2 50~ 60%, Al} 2 O 3 0~ 7.5%, 0~10% MgO, CaO 0~12%, BaO 0~12 _{%, SrO 0~15%, MgO +} CaO + SrO + BaO 10~30%, ZrO 2 4.4 ~10%, Na 2 O 0~15%, K 2 O containing 0-15%, the liquidus temperature is 1150 ° C. or less, the strain A point is a thermal expansion coefficient in the range of 550 degreeC or more and 30-380 degreeC, It is 50-95x10 < ^-7 > / degreeC, It is characterized by the above-mentioned. The reason for determining the composition range and characteristics in this way is as described above.

  The surface resistance may be adjusted by forming a conductive film on the surface of the glass spacer of the present invention.

  The glass spacer of the present invention is used as it is, but may be used as a member for assembling a spacer having a complicated shape such as a cross beam. Moreover, in order to produce the spacer of this invention, it is preferable to utilize the method using the above-mentioned stretch molding.

  According to the method of the present invention, it is possible to manufacture a glass spacer that has high dimensional accuracy and that is not damaged or deformed in the heat treatment process in the manufacturing process of the flat display device. In FED applications, a spacer with a high aspect ratio is preferred so as not to block electrons emitted from the emitter. However, in the method of the present invention, such a spacer can be easily manufactured.

  In addition, if a strip glass cut from a plate glass is used as the material glass, the production cost of the material glass can be reduced, so that the spacer can be produced at low cost.

  The glass spacer of the present invention has high dimensional accuracy, and is not damaged or deformed in the heat treatment process in the manufacturing process of the flat display device. Therefore, the glass spacer is suitable as a flat display device, particularly as a glass spacer for FED.

  Example 1 evaluates various properties of the glass used in the present invention.

  In the evaluation, glass raw materials were first prepared so as to have the compositions shown in Tables 1 and 2, and melted at 1600 ° C. for 4 hours using a platinum pot. Thereafter, the molten glass was poured out on a carbon plate, formed into a plate shape, and subjected to various evaluations. The results are shown in each table.

In addition, about the devitrification at the time of reheating, it measured by the following methods. First, the surface of the produced glass sample was optically polished and heat-treated at a temperature of 10 ^6.5 dPa · s for 1 hour. Next, after cooling to room temperature, the surface was observed with a microscope, and the size and number of devitrified crystals were confirmed. At this time, if the number is 0 to 20 pieces / mm ² of devitrification crystal ◎, 〇 if it is 21 to 50 pieces / mm ^2, and △ and if it is 51 to 100 cells / mm ^2. From this evaluation, if ◎, ○, Δ, that is, the number of devitrified crystals having a major axis of 1 μm or more is 100 pieces / mm ² or less, it can be determined that the glass is less likely to cause devitrification crystals by reheating during stretch molding.

  The density was measured by the well-known Archimedes method.

  The strain point was measured based on the method of ASTM C336-71. The higher this value, the higher the heat resistance of the glass.

  The softening point was measured based on the method of ASTM C338-93.

Viscosity 10 ^4.0, 10 ^3.0, 10 ^2.5 Temperature in dPa · s of was measured by a platinum ball pulling method. The lower this temperature, the better the meltability.

  The liquid phase temperature is measured by crushing the glass, passing through a standard sieve 30 mesh (500 μm), putting the glass powder remaining on 50 mesh (300 μm) into a platinum boat, holding it in a temperature gradient furnace for 24 hours, The temperature at which precipitation occurs is measured. The liquid phase viscosity indicates the viscosity of each glass at the liquid phase temperature. It can be said that the higher the liquidus viscosity and the lower the liquidus temperature, the better the devitrification resistance and the better the moldability.

  The thermal expansion coefficient is obtained by measuring an average thermal expansion coefficient at 30 to 380 ° C. using a dilatometer.

  The volume resistivity logρ (unit: common logarithm of Ω · cm) was measured by a method based on ASTM D257. The infrared transmittance at 1100 nm of the glass having a thickness of 2.8 mm was measured using UV3100 (Shimadzu Corporation) at a slit width of 2 nm.

  Example 2 demonstrates the manufacturing method of the glass spacer of this invention concretely.

  First, No. 1 in Example 1 was used. A plate glass having a composition of 8 and a float-formed thickness of 2.8 mm was prepared. An unpolished product was used for the plate glass.

  Next, the plate glass was cut into a size of 1000 × 28 × 2.8 mm, and only the cut surface was polished to obtain a strip-shaped glass.

Subsequently, no. From the top of the electric furnace maintained at a temperature of 800 ° C. to 1000 ° C. corresponding to a viscosity of 10 ^8.4 dPa · s to 10 ^5.4 dPa · s of the glass No. 8, the strip glass is continuously applied at a rate of 5 mm / min. It was heated so that it could be sent and softened and deformed. Furthermore, a glass spacer having a size of 100 mm × 2 mm × 0.2 mm is obtained by holding the lower end of the strip-shaped glass that has started to extend downward due to softening deformation, stretching it by applying a tensile force while being driven by a pair of driving rollers, and cutting it. Got.

The height h of the glass spacer thus produced was observed with a microscope with an image processing device every 10 mm. Table 3 shows the heights h ₁ to h ₁₁ of the respective measurement points.

From Table 3, the glass spacer produced by the method of the present invention has a difference between the maximum height h _max and the minimum height h _min of the spacer of about 0.04% of the value of the average height h _ave. It was confirmed that the dimensional accuracy was high.

  The glass spacer of the present invention is not limited to FED use, and can be used as a spacer for other flat display devices.

It is structure schematic explanatory drawing of FED. It is an example of the spacer of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Spacer 2 Gate line 3 Back plate 4 Emitter line 5 Electron emission element 6 Black matrix 7 Phosphor 8 Front plate

Claims (4)

In mass percentage, SiO ₂ 50-60%, Al ₂ O ₃ 0-7.5%, ZrO ₂ 4.4-10%, strain point 550 ° C or higher, liquidus temperature 1150 ° C or lower, 30- A step of preparing a plate material glass having a thermal expansion coefficient at 380 ° C. of 82 to 88 × 10 ⁻⁷ / ° C. and formed by a float process, and a strip glass produced by cutting the material glass And a step of stretch-molding the strip-shaped glass under the condition that a devitrifying crystal having a major axis of 1 μm or more does not precipitate in the glass, and a step of cutting the stretched glass molded body. Manufacturing method of glass spacer for flat panel display. The method for producing a glass spacer for a flat display device according to claim 1, wherein a plate glass having an unpolished surface is used as the material glass. The raw material glass has a property that 100 / mm ² or less devitrified crystals having a major axis of 1 μm or more deposited on the glass surface when heat-treated at a temperature corresponding to a viscosity of 10 ^6.5 dPa · s for 1 hour. 2. The method for producing a glass spacer for a flat panel display device according to claim 1, wherein glass is used. A glass spacer for a flat display device, which is produced by the method according to claim 1.

Images