JP5152686B2 - Support frame forming material - Google Patents

Description

The present invention relates to a support frame forming material , and is preferably a support frame suitable for a flat display device, particularly a fluorescent display tube, a plasma display (hereinafter referred to as PDP), and a field emission display (hereinafter referred to as FED). It relates to a forming material .

  The flat display device has a structure in which a support frame is interposed between a front glass substrate having a phosphor and a rear glass substrate. The flat display device has a structure hermetically sealed with sealing glass. The space inside the apparatus formed by the front glass substrate, the rear glass substrate, and the support frame is maintained in a vacuum state, a reduced pressure state, or the like.

  The support frame used in the flat display device is a member constituting the side frame of the flat display device. FIG. 2A is a schematic cross-sectional view in the plate thickness direction of the conventional flat display device 1, and a support frame 13 is interposed between the front glass substrate 11 and the rear glass substrate 12. The support frame is produced, for example, by performing various processes on a glass substrate having a strain point of 580 ° C. or higher. The front glass substrate 11 and the support frame 13, and the back glass substrate 12 and the support frame 13 are hermetically sealed using a sealing glass 14. FIG. 2B is a schematic cross-sectional view in the plane direction of the conventional flat display device 1, and is a schematic cross-sectional view in the plane direction as viewed from above on the front glass substrate side. It is. The support frame 13 has a frame shape and is formed on the outer peripheral edge of the rear glass substrate 12.

  The support frame used in the flat display device is required to have high dimensional accuracy in order to keep the distance between the front glass substrate and the rear glass substrate constant. When the dimensional accuracy of the support frame is poor, there are portions where the distance between the front glass substrate and the rear glass substrate is locally different. In such a case, in the flat display device, the accelerating voltage applied between the front plate and the back plate varies, or the speed of electrons colliding with the phosphor changes, which adversely affects the luminance characteristics of the flat display device. There is a risk of effects. The flat display device is also required to have excellent mechanical strength of the support frame because the inside of the device is in a vacuum state. Further, since the flat display device undergoes various heat treatment steps, the support frame is also required to have good heat resistance (softening and deformation due to heat treatment and no dimensional change). Specifically, since the flat display device uses sealing glass for hermetic sealing, the support frame is required not to be softened and deformed in a temperature range where the sealing glass flows, for example, about 430 ° C.

  In order to satisfy these required characteristics, the conventional support frame has been manufactured by cutting a glass substrate that has been plate-formed. Patent Document 1 discloses an image formation in which an image is formed by irradiating an electron beam emitted from an electron-emitting device while being arranged opposite to the rear glass substrate on which the electron-emitting device is mounted and the rear glass substrate. A method of manufacturing a flat display device having a front glass substrate on which a member is mounted, a support frame between the rear glass substrate and the front glass substrate and supporting the periphery, and having these members joined with sealing glass to form an airtight structure However, according to the description in paragraph 0030 of the specification, the support frame used in this manufacturing method is manufactured by cutting blue sheet glass.

In Patent Document 2, a step of applying a paste of crystalline glass powder to a portion of a pair of substrates facing each other via a support frame and forming a support frame around the substrate, and baking the paste to crystallized glass Forming a support frame, applying an amorphous sealing glass powder paste to a sealing portion of the support frame, firing the paste to form a sealing layer, support frame and sealing The step of storing the one substrate on which the layer is formed and the other substrate facing each other in a vacuum chamber and exhausting, after exhausting, maintaining the exhausted state or after adding the specific gas after exhausting, A manufacturing method of an airtight container of a flat display device is described, which includes a step of overlaying the other substrate on a sealing layer and softening and melting the sealing layer to seal. The support frame used in this manufacturing method is produced by sintering crystalline glass powder.
JP-A-11-317164 JP-A-2005-213125

  The conventional support frame described in Patent Document 1 has the following problems. In order to form a support frame by cutting a glass substrate, it has been difficult to ensure high dimensional accuracy. In particular, the larger the screen size of the flat display device, the more difficult it is to cut the glass substrate, making it difficult to produce a support frame.

  Further, in order to cut a glass substrate into a frame shape, there are restrictions on the cutting method, and it is necessary to adopt a special cutting method as the size of the support frame to be manufactured increases. Therefore, the support frame manufactured by the above method is expensive to manufacture, and the cost of the flat display device is increased accordingly.

  Furthermore, the above method tends to cause fine cracks in the support frame. Therefore, the support frame manufactured by the above method may cause impact damage of the support frame starting from fine cracks, and it may be difficult to ensure the airtight reliability of the flat display device. Furthermore, when the glass substrate is cut and the support frame is formed, a fine cutting piece generated when the glass substrate is cut adheres to the glass substrate, so it is necessary to separately add a step of cleaning the support frame after the cutting process, The manufacturing process of the support frame has become unduly long, and the manufacturing efficiency of the support frame has been reduced.

  On the other hand, a method of cutting a glass substrate into a strip shape in advance and then heat-sealing them to produce a frame-like support frame has been studied. However, even with this method, it is impossible to solve the above-mentioned problem that the manufacturing cost increases and the manufacturing process of the support frame becomes unduly long.

  The support frame described in Patent Document 2 is produced by sintering crystalline glass powder. However, the crystalline glass powder has a property that crystals are precipitated on the glass when heat treatment is performed. Therefore, in order to precipitate a desired crystal, temperature control is strictly performed in the supporting frame sintering process. There was a need. If the temperature control in the sintering process is inappropriate, unintended crystals may be deposited on the crystalline glass, or crystals may be deposited on the glass before the sintering of the support frame is completed. In addition, once the crystalline glass powder is precipitated in the glass, the glass is not softened and deformed even when heat treatment is applied. According to Patent Document 2, since the sintering of the support frame is the final stage of the assembly of the flat display device, if the support frame is improperly sintered, the manufacturing efficiency of the flat display device is significantly reduced. become. Furthermore, it is difficult to stabilize the timing of crystal precipitation because the crystalline glass powder easily varies in the temperature range where the crystal precipitates if the thermal history and impurity content during glass production differ. .

  If the support frame can be directly formed on the surface of the glass substrate, it is considered that the above problems can be solved. Specifically, after applying a paste containing non-crystalline glass powder on the surface on which the support frame of the back glass substrate is to be formed, the paste is glazed (debindered) and sintered to form the support frame. If this can be formed, the above problem can be solved. However, there is almost no technical knowledge about the glass composition suitable for forming the support frame by the above method.

Therefore, the present invention proposes a material suitable for forming the support frame of the flat display device, and a technical problem is to contribute to improving the reliability of the flat display device and reducing the product cost.

The present inventors, as a result of extensive studies, _SiO 2 5 to _30% of the glass composition of the glass powder in mole% in terms of _{oxide, B 2 O 3 25~45%,} 20~60% ZnO, Al 2 O _{3 0~10%, R 2 O 1~20} % ( however, _{R 2} O _{refers Li 2 O, Na 2 O,} K 2 O, the _{Cs 2 O), Li 2 O} 0~15%, Na 2 _{O 0~15%, K 2 O 0~} 4%, R'O 0~25% ( however, R'O refers MgO, CaO, SrO, and BaO), 0~15% MgO, CaO 0~15 _{%, BaO 0~15%, SrO 0~15} %, and regulated to ZrO ₂ + TiO ₂ 0~10%, without containing the actual qualitatively PbO, the technical by adding a predetermined amount of refractory filler powder It has been found that the problem can be solved, and is proposed as the present invention. Here, “substantially not containing PbO” in the present invention refers to a case where the PbO content in the glass composition of the glass powder is 1000 ppm or less.

Since the support frame forming material of the present invention regulates the glass composition of the glass powder within the above range, the thermal stability of the glass is good, and crystals do not precipitate during the sintering process of the support frame. . That is, when the support frame is formed, the glass is not devitrified even if the glass is sintered, the support frame can be formed stably, and the dimensional accuracy of the support frame can be easily improved. Furthermore, if the glass composition of the glass powder is within the above range, even if a refractory filler is added to the glass powder composed of the glass composition, the glass does not devitrify, and the adjustment and support of the thermal expansion coefficient of the support frame Improvement of the mechanical strength of the frame can be easily achieved. Therefore, it is possible to reliably support the inside of the flat display device even when the inside of the flat display device is in a vacuum state, and it is difficult for cracks to start from the support frame even when a mechanical shock is applied to the flat display device. Become. When the support frame is formed, if the glass is devitrified, the support frame and the rear glass substrate are not fused, and the support frame may not be controlled to a desired size.

Moreover, since the support frame forming material of the present invention regulates the glass composition of the glass powder within the above range, the softening point of the glass powder can be regulated within an appropriate range. That is, if the glass composition of the glass powder is within the above range, the glass can be sintered at a temperature lower than the strain point of the high strain point glass substrate (for example, 580 ° C. or lower), and the strain point of the high strain point glass substrate. The support frame can be formed at the following low temperature. Further, the support frame forming material of the present invention can be sintered at a temperature below the strain point of the high strain point glass substrate, and at the same time can firmly fuse the back glass substrate and the support frame. Further, the support frame is softened and deformed in the subsequent heat treatment process (sealing process, vacuum evacuation process) of the flat display device, and no dimensional change occurs. Specifically, when the glass composition of the glass powder is within the above range, the softening point of the support frame forming material can be set to 490 to 580 ° C., further 500 to 560 ° C., and the above effects can be enjoyed. .

The support frame forming material of the present invention employs SiO ₂ —B ₂ O ₃ —ZnO glass as a glass composition system of glass powder, and has a glass composition that does not substantially contain PbO. Therefore, since the support frame forming material of the present invention does not contain PbO, which is an environmental load substance, it is possible to accurately meet recent environmental requirements.

The support frame forming material of the present invention is typically applied to the back glass substrate as a glass paste after being processed at the end flour, after glaze and sintered. Therefore, if the support frame forming material of the present invention is used, not only the process of cutting the glass substrate becomes unnecessary, but also the process of sealing the back glass substrate and the support frame with the sealing glass becomes unnecessary. In addition to making it easier to keep the distance between the glass substrate and the back glass substrate constant, this contributes to a reduction in the manufacturing cost of the flat display device.

  FIG. 1 shows a schematic cross-sectional view in the thickness direction of the flat display device according to the present invention. A support frame 13 is interposed between the front glass substrate 11 and the rear glass substrate 12. The support frame is formed by applying a glass paste containing glass powder made of the glass composition on the outer peripheral edge of the back glass substrate, and then glazing and sintering the glass paste. The front glass substrate 11 and the support frame 13 are hermetically sealed using a sealing glass 14.

In the support frame forming material of the present invention, the glass powder is expressed in mol% in terms of the following oxide, and the glass composition is SiO ₂ 7-25%, B ₂ O ₃ 25-45%, ZnO 25-55%, Al ₂ O ₃ 0 to 5%, R ₂ O 5 to 15% (where R ₂ O represents Li ₂ O, Na ₂ O, K ₂ O, Cs ₂ O), Li ₂ O 0 to 10%, _{Na 2 O 0~10%, K 2} O 0~ 4%, R'O 0~15% ( however, R'O refers MgO, CaO, SrO, and BaO), 0~5% MgO, CaO 0 _{~5%, BaO 0~10%, SrO} 0~5%, ZrO 2 + containing TiO 2 0 to 7%, and is preferably substantially free of PbO.

The support frame forming material of the present invention preferably uses alumina as the refractory filler powder.

The support frame forming material of the present invention preferably has a softening point of 490 to 580 ° C. The “softening point” in the present invention refers to a value measured by macro-type differential thermal analysis (DTA).

The support frame forming material of the present invention preferably has a thermal expansion coefficient of 64 to 86 × 10 ⁻⁷ / ° C. In addition, the "thermal expansion coefficient" as used in the field of this invention points out the value measured in the temperature range of 30-300 degreeC with the push rod type | formula thermal expansion coefficient measurement (TMA) apparatus.

The support frame forming material of the present invention is preferably used for a flat display device.

The reason why the glass composition of the glass powder is limited as described above in the support frame forming material of the present invention will be described below. In addition, the following% display points out mol% unless there is particular limitation.

SiO ₂ is a component that forms a glass skeleton and is a glass-forming oxide. Further, SiO ₂ is a component for improving the weather resistance of the glass. Its content is 5-30%, preferably 7-25%, more preferably 10-20%. When SiO ₂ is more than 30%, the softening point of the glass becomes too high, and it becomes difficult to form a support frame at a low temperature of 600 ° C. or lower. If the SiO ₂ content is less than 5%, the glass becomes thermally unstable, making it difficult to form a support frame with high dimensional accuracy.

B ₂ O ₃ is a component that forms a skeleton of glass and is a glass-forming oxide. Its content is 2 5 to 45%, good Mashiku is 30-42%. If the content of B ₂ O ₃ is less than 25 %, the glass becomes thermally unstable, and the glass tends to devitrify during melting or sintering. On the other hand, if the content of B ₂ O ₃ is more than 45 %, the viscosity of the glass becomes too high and it becomes difficult to sinter at a low temperature of 600 ° C. or lower.

  ZnO is a component that decreases the coefficient of thermal expansion without increasing the melting temperature and softening point of the glass, and is a component that suppresses devitrification when the glass is melted or sintered. Its content is 20-60%, preferably 25-55%, more preferably 25-42%. When the content of ZnO is more than 60%, the balance in the glass composition is conversely lost, and the thermal stability of the glass is impaired. As a result, the glass is easily devitrified. If the ZnO content is less than 20%, the effect of reducing the thermal expansion coefficient becomes poor, and the effect of suppressing devitrification at the time of melting or sintering of the glass becomes poor.

Al ₂ O ₃ is a component that improves the weather resistance of glass. The content is preferably 0 to 10%, more preferably 0 to 5%. When Al ₂ O ₃ is more than 10%, the softening point of the glass becomes too high, and it becomes difficult to form a support frame at a low temperature of 600 ° C. or lower.

R ₂ O is a component that lowers the softening point of glass. Its content is 0-25%, preferably 1-20%, more preferably 5-15%. When R ₂ O is more than 25%, thermal stability of the glass is impaired, resulting in the glass tends to be devitrified.

Li ₂ O is a component that lowers the softening point of glass. Its content is 0-15%, preferably 0-10%, more preferably 0.1-7%. When li ₂ O is more than 15%, thermal stability of the glass is impaired, resulting in the glass tends to be devitrified. On the other hand, if Li ₂ O is more than 15%, the thermal expansion coefficient becomes too large, and it becomes difficult to match the thermal expansion coefficient with the glass substrate, and as a result, cracks are likely to occur in the glass substrate.

Na ₂ O is a component that lowers the softening point of glass. Its content is 0-15%, preferably 0-10%, more preferably 0.1-10%. When Na ₂ O is more than 15%, the thermal stability of the glass is impaired, and as a result, the glass is easily devitrified.

K ₂ O is a component that lowers the softening point of glass. Its content is from 0 to 4 %, preferably from 0.1 to 4 %. When K ₂ O is more than 4 %, the thermal stability of the glass is impaired, and as a result, the glass is easily devitrified.

In addition, it is preferable that Li ₂ O, Na ₂ O, and K ₂ O are each contained in an amount of 0.1% or more because an alkali mixing effect can be enjoyed.

  R'O is a component that improves the thermal stability of the glass. Its content is 0-25%, preferably 0-15%, more preferably 0-6%. If R'O is more than 25%, the thermal stability of the glass is impaired, and as a result, the glass tends to be devitrified.

  MgO is a component that improves the thermal stability of the glass. The content is 0 to 15%, preferably 0 to 10%, more preferably 0 to 5%. If the content of MgO is more than 15%, the balance in the glass composition is lost, and the thermal stability of the glass is impaired. As a result, the glass is easily devitrified. Further, from the viewpoint of improving the thermal stability of the glass, the MgO content is preferably 0.1% or more.

  CaO is a component that improves the thermal stability of the glass. The content is 0 to 15%, preferably 0 to 10%, more preferably 0 to 5%. When the content of CaO is more than 15%, the balance in the glass composition is conversely lost, and the thermal stability of the glass is impaired. As a result, the glass is easily devitrified. Moreover, it is preferable that content of CaO shall be 0.1% or more from a viewpoint of improving the thermal stability of glass.

  SrO is a component that improves the thermal stability of the glass. The content is 0 to 15%, preferably 0 to 10%, more preferably 0 to 5%. When the content of SrO is more than 15%, the balance in the glass composition is lost, and the thermal stability of the glass is impaired. As a result, the glass is easily devitrified. Further, from the viewpoint of improving the thermal stability of the glass, the SrO content is preferably 0.1% or more.

  BaO is a component that improves the thermal stability of the glass. The content is 0 to 15%, preferably 0 to 10%, more preferably 0 to 5%. When the content of BaO is more than 15%, the balance in the glass composition is lost, and the thermal stability of the glass is impaired. As a result, the glass is easily devitrified. Moreover, when there is more content of BaO than 15%, a thermal expansion coefficient will become high too much and it will become difficult to match a glass substrate and a thermal expansion coefficient. On the other hand, from the viewpoint of improving the thermal stability of the glass, the BaO content is preferably 0.1% or more.

ZrO ₂ and TiO ₂ are components that improve the water resistance and chemical resistance of glass. The total content is preferably 0 to 10%, more preferably 0 to 7%. When the content of ZrO ₂ and TiO ₂ is more than 10% in total, the glass tends to devitrify and the fluidity of the glass tends to be impaired. On the other hand, if the total content of ZrO ₂ and TiO ₂ is more than 10%, the viscosity of the glass becomes too high and it becomes difficult to form a support frame at a temperature of 600 ° C. or lower.

ZrO ₂ is a component that improves the water resistance and chemical resistance of glass. The content is preferably 0 to 10%, more preferably 0 to 5%. If the content of ZrO ₂ is more than 10%, the glass tends to devitrify, and the fluidity of the glass tends to be impaired. On the other hand, if the content of ZrO ₂ is more than 10%, the viscosity of the glass becomes too high, and it becomes difficult to form a support frame at a temperature of 600 ° C. or lower.

TiO ₂ is a component that improves the water resistance and chemical resistance of glass. The content is preferably 0 to 10%, more preferably 0 to 5%. If the content of TiO ₂ is more than 10%, the glass tends to devitrify, and the fluidity of the glass tends to be impaired. On the other hand, if the content of TiO ₂ is more than 10%, the viscosity of the glass becomes too high, and it becomes difficult to form a support frame at a temperature of 600 ° C. or lower.

P ₂ O ₅ is a component that suppresses devitrification at the time of melting. However, if the amount added is more than 5%, it is not preferable because the glass tends to phase-separate at the time of melting.

MoO ₃ , La ₂ O ₃ , Y ₂ O _3, and Gd ₂ O ₃ are components that suppress the phase separation of the glass at the time of melting, but if the total amount of these is more than 7%, the glass has a high softening point. It becomes difficult to sinter at a temperature of 600 ° C. or less.

  Moreover, even if it is another component, it is possible to add to 15% in the range which does not impair the characteristic of glass.

In the support frame forming material of the present invention, the glass powder does not substantially contain PbO for environmental reasons. Moreover, when PbO is contained in the glass composition, Pb ²⁺ present in the glass may diffuse to reduce the electrical insulation.

The glass composition for forming a support frame having the above glass composition is preferably processed into a powder form and used as a support frame forming material. When glass powder is used alone as a support frame forming material, it contributes to simplification of the manufacturing process of the support frame forming material. Further, when glass powder is used alone as a support frame forming material, there is no possibility that the refractory filler powder acts as a crystal nucleus, so that the thermal stability of the glass is not impaired. The glass composition for forming a support frame having the above glass composition has a glass softening point of 490 to 580 ° C., further 500 to 560 ° C., a thermal expansion coefficient of 64 to 86 × 10 ⁻⁷ / ° C., and further 70 to 82. Since it can be set to ^{x10 -7} / ° C, it can be suitably used as a support frame forming material.

If the thermal expansion coefficient does not fit, for example by using a glass powder high thermal expansion coefficient, when forming the support frame in such a high strain point glass substrate (thermal expansion coefficient of 85 × 10 -7 ^/ ℃), a glass powder a mixture of refractory filler powder, it this and the support frame is forming material. The thermal expansion coefficient of the support frame forming material is preferably designed to be equal to or lower than the thermal expansion coefficient of the glass substrate. Specifically, it is preferable to design so that the value obtained by subtracting the thermal expansion coefficient of the support frame forming material from the thermal expansion coefficient of the glass substrate is −5 × 10 ⁻⁷ / ° C. to 20 × 10 ⁻⁷ / ° C. . This is to reduce the strain remaining on the glass substrate and the support frame after the support frame is formed, and to prevent stress destruction of the glass substrate and the support frame.

If the thermal expansion coefficients of the glass substrate and the support frame forming material are greatly different, the heat shrinkage behavior of the glass substrate and the support frame forming material is different during the formation of the support frame by heat treatment. There is a risk of warping of the substrate. According to the investigation by the present inventor, the value obtained by subtracting the thermal expansion coefficient of the support frame forming material from the thermal expansion coefficient of the glass substrate is designed to be −5 × 10 ⁻⁷ / ° C. to 20 × 10 ⁻⁷ / ° C. For example, the warp of the glass substrate after the support frame is formed can be reduced, specifically, the warp of the glass substrate can be 50 μm or less.

  In addition to adjusting the thermal expansion coefficient, for example, a refractory filler powder can be added to maintain the shape of the support frame and improve the mechanical strength.

When mixing refractory filler powder to the glass powder, the mixing ratio is, the glass powder is 55 to 99 vol%, the refractory filler powder Ri 1-45 vol% der, glass powder 60 to 95 vol%, refractory More preferably, the conductive filler powder is 5 to 40% by volume. The reason why the ratio of the two is defined in this manner is that when the amount of the refractory filler powder is less than 1% by volume, the above-described effect tends to be hardly obtained, and when the amount is more than 45% by volume, it is difficult to form a dense support frame. Because.

The refractory filler powder is required to have low reactivity so as not to decrease the thermal stability even when added to the SiO ₂ —B ₂ O ₃ —ZnO-based glass powder. High mechanical strength is required. Further, as the refractory filler powder, it is preferable to use a refractory filler powder substantially not containing PbO. Various materials can be used as the refractory filler powder. Specifically, alumina, cordierite, zircon, willemite, zirconia, titanium oxide, tin oxide, niobium oxide, zirconium phosphate, aluminum titanate, β-eucryptite, β-spodumene, β-quartz solid solution, mullite, a compound having a basic structure of [AB ₂ (MO ₄ ) ₃ ],
A: Li, Na, K, Mg, Ca, Sr, Ba, Zn, Cu, Ni, Mn etc. B: Zr, Ti, Sn, Nb, Al, Sc, Y etc. M: P, Si, W, Mo etc. Alternatively, a mixture thereof may be appropriately selected and used according to the purpose. In particular, cordierite is effective in reducing the thermal expansion coefficient of the support frame, and alumina is effective in maintaining the shape of the support frame.

  The support frame forming material of the present invention may contain up to 20% of a pigment such as Mn—Fe—Al—O, Mn—Fe—Co—O, or Co—O.

  The softening point of the support frame forming material of the present invention is preferably 490 to 580 ° C, more preferably 500 to 560 ° C, and still more preferably 520 to 550 ° C. If the softening point of the support frame forming material is within the above range, the glass can be sintered at a temperature lower than the strain point of the high strain point glass substrate (for example, 580 ° C. or lower), thereby forming a support frame with high dimensional accuracy. It becomes possible to do. Further, if the softening point of the support frame forming material is within the above range, it can be sintered at a temperature below the strain point of the high strain point glass substrate, and at the same time, the back glass substrate and the support frame can be firmly fused. Can do. Further, in the subsequent heat treatment process (sealing process, vacuum evacuation process) of the flat display device, the support frame is softened and deformed because it is not usually heated to a temperature higher than the strain point of the high strain point glass substrate. There is no dimensional change. When the softening point of the support frame forming material is lower than 490 ° C., the glass is easily softened and deformed when the support frame forming material is sintered, and it is difficult to ensure the dimensional stability of the support frame. Further, if the softening point of the support frame forming material is larger than 580 ° C., it becomes difficult to sinter the glass at a temperature below the strain point of the high strain point glass, and the back glass substrate and the support frame are not properly fused. It becomes difficult to ensure the airtight reliability of the flat display device.

Thermal expansion coefficient of the support frame forming material of the present invention is preferably 64~86 × 10 ^-7 / ℃, more preferably 67~84 × 10 ^-7 / ℃, more preferably 69~77 × 10 ^-7 / ℃ . When the thermal expansion coefficient of the support frame forming material is within the above range, the thermal shrinkage behavior of the high strain point glass substrate and the support frame forming material can be matched when forming the support frame by heat treatment. After the formation, the warp of the high strain point glass substrate can be reduced to 50 μm or less. If the thermal expansion coefficient of the support frame forming material is less than 67 × 10 ⁻⁷ / ° C., unreasonable stress may remain on the high strain point glass substrate. Further, when the glass is designed so that the thermal expansion coefficient is less than 67 × 10 ⁻⁷ / ° C., the softening point of the glass tends to increase, and it becomes difficult to form a support frame at a low temperature of 600 ° C. or lower. If the thermal expansion coefficient of the support frame forming material is larger than 86 × 10 ⁻⁷ / ° C., unreasonable stress remains on the high strain point glass substrate, that is, unreasonable compressive stress remains on the high strain point glass substrate. The probability that the device will break due to thermal shock or the like increases.

  The support frame forming material is easy to handle when it is kneaded uniformly with a vehicle and used as a paste. The vehicle is mainly composed of an organic solvent and a resin, and the resin is added for the purpose of adjusting the viscosity of the paste. Moreover, surfactant, a thickener, a thermoplastic resin, etc. can also be added as needed. The produced paste is applied using an applicator such as a dispenser or a screen printer.

  As organic solvents, N, N′-dimethylformamide (DMF), α-terpineol, higher alcohol, γ-butyllactone (γ-BL), tetralin, butyl carbitol acetate, ethyl acetate, isoamyl acetate, diethylene glycol monoethyl ether , Diethylene glycol monoethyl ether acetate, 2,2,4-trimethyl-1,3-pentadiol monoisobutylate, diethylene glycol monoethyl ether acetate, benzyl alcohol, toluene, 3-methoxy-3-methylbutanol, water, triethylene glycol Monomethyl ether, triethylene glycol dimethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monobutyl ether, tripropylene glycol Methyl ether, tripropylene glycol monobutyl ether, propylene carbonate, dimethyl sulfoxide (DMSO), N-methyl-2-pyrrolidone and the like can be used. In particular, α-terpineol is preferable because it is highly viscous and has good solubility in resins and the like.

  As the resin, acrylic resin, ethyl cellulose, polyethylene glycol derivative, nitrocellulose, polymethylstyrene, polyethylene carbonate, methacrylic acid ester and the like can be used. In particular, an acrylic resin and ethyl cellulose are preferable because they are highly viscous and have good thermal decomposability.

  The plasticizer is a component that controls the drying speed and imparts flexibility to the dry film. As the plasticizer, butyl benzyl phthalate, dioctyl phthalate, diisooctyl phthalate, dicapryl phthalate, dibutyl phthalate, polymethyl methacrylate, polyethyl methacrylate, polybutyl methacrylate, etc. can be used. Can be used.

  In order to form a support frame using such a paste, first, these pastes are applied using a screen printing method, a dispenser applicator, or the like to form a coating layer having a predetermined thickness. The coating layer is dried, glazed, and sintered to form a support frame. In particular, if a support frame is formed using a dispenser coating machine, a frame-shaped support frame can be formed by a single application, which is preferable in terms of manufacturing efficiency.

Further, as the method of forming the support frame, the support frame shape Naruzai charge was processed into tablets (sintered body) having a predetermined shape, the method of fusing and the like to which a rear glass substrate. By adopting this method, it is possible to form a support frame with higher dimensional accuracy than the method using the above-described dispenser applicator. Further, as a method for forming the support frame, the support frame shape Naruzai fee is processed into a predetermined sheet, which was laminated to a predetermined shape of the support frame on the back glass substrate, and thereafter a method for sintering. By adopting this method, it is possible to form a support frame with higher dimensional accuracy than the method using the above-described dispenser applicator.

  The support frame forming material of the present invention is preferably used for a flat display device. As described above, the support frame forming material of the present invention can increase the dimensional accuracy of the support frame and at the same time increase the strength of the support frame, and therefore can be suitably used for this application. Specific examples of the flat display device include FED, PDP, inorganic EL, and fluorescent display tube. In particular, the support frame forming material of the present invention is more preferably used for FED. Since the support frame forming material of the present invention can improve the dimensional accuracy of the support frame, the distance between the front glass substrate and the back glass substrate can be made uniform, and the space between the front plate and the back plate is within the FED apparatus. It is difficult to cause a situation in which the luminance characteristics of the FED are adversely affected by variations in the applied acceleration voltage or changes in the velocity of electrons that collide with the phosphor. In addition, since the support frame forming material of the present invention has excellent mechanical strength, even if the inside of the FED apparatus is in a high vacuum state, the support frame is hardly damaged by impact and the reliability of the FED can be ensured. . Needless to say, the FED referred to in the present invention includes all types of FEDs having various electron-emitting devices.

  Hereinafter, the present invention will be described in detail based on examples.

Samples A to L described in Tables 1 to 3 were prepared as follows.

  First, a glass batch in which raw materials such as various oxides and carbonates were prepared so as to have the glass compositions shown in Tables 1 to 3 was prepared, and this was put in a platinum crucible and melted at 1250 ° C. for 3 hours. Next, a part of the molten glass was poured into a stainless steel mold as a measurement sample, and the other molten glass was formed into a thin piece with a water-cooled roller. In addition, the sample for measurement poured out to the metal mold | die performed the predetermined slow cooling process (annealing) after shaping | molding. Finally, the glass flakes were pulverized with a ball mill and passed through a sieve having an opening of 105 μm to obtain samples having an average particle diameter of about 10 μm.

  Using the above samples, the glass transition point, softening point, thermal expansion coefficient and devitrification state were evaluated. The results are shown in Tables 1-3.

  The glass transition point and the thermal expansion coefficient were determined by a push rod type thermal expansion coefficient measuring apparatus. The thermal expansion coefficient was measured in a temperature range of 30 to 300 ° C.

  The softening point was determined by a differential thermal analyzer. If the softening point is 560 ° C. or lower, a dense support frame can be formed by baking at 570 ° C. for 30 minutes, and the back glass substrate can be firmly fused.

  Samples A to L in Tables 1 to 3 were obtained by observing the surface crystals of the sample visually using an optical microscope (100 times magnification) after holding the powder pressure-molded body in a baking furnace at 570 ° C. for 30 minutes. The devitrification state was evaluated. The case where no devitrification was observed was indicated as “◯”, and the case where devitrification was observed as “x”. The temperature raising / lowering rate was 10 ° C./min.

  As for the flow diameter, a powder having a weight corresponding to the density of each sample was dry-pressed into a button shape having an outer diameter of 20 mm using a mold, and this was pressed into a 40 mm × 40 mm × 2.8 mm thick high strain point glass substrate (Nippon Electric Glass Co., Ltd.). The obtained button was placed on PP-8C), heated in air at a rate of 5 ° C./minute, fired at 570 ° C. for 30 minutes, and then cooled to room temperature at 5 ° C./minute. It was evaluated by measuring the diameter. Further, when the flow diameter is 16.6 to 17.5 mm, it means that dimensional stability and shape stability are good under the tested firing conditions.

Samples A to J in Tables 1 and 2 had a thermal expansion coefficient of 65.5 to 92.2 × 10 ⁻⁷ / ° C. Samples A to J in Tables 1 to 3 have a glass transition point of 440 to 460 ° C, a softening point of 534 to 558 ° C, and a flow diameter of 17.0 to 17.4 mm. Furthermore, the samples A to J had good evaluation of the devitrification state and had good thermal stability.

Sample K in Table 3 had a higher glass transition point and softening point because SiO ₂ was more than the predetermined range, and was not sintered by firing at 570 ° C. for 30 minutes. In Sample L in Table 3, since SiO ₂ it was less than the predetermined range, the evaluation of devitrification in poor condition.

  The glass powder sample of Table 1 and the predetermined refractory filler powder in the table were mixed to obtain a support frame forming material shown in Table 4. Sample No. in Table 4 1-5 have shown the Example. Sample No. About 1-5, the thermal expansion coefficient, the softening point, the devitrification state, and the flow diameter were evaluated. The thermal expansion coefficient, softening point, and devitrification state were measured by the same method as that for the glass sample.

  As for the flow diameter, a powder having a weight corresponding to the synthesis density of each sample was dry-pressed into a button shape having an outer diameter of 20 mm using a mold, and this was pressed into a 40 mm × 40 mm × 2.8 mm thick high strain point glass substrate (Nippon Electric Glass). It was placed on PP-8C), heated at a rate of 5 ° C./min in air, baked at 570 ° C. for 30 min, and then cooled to room temperature at 5 ° C./min. Evaluation was made by measuring the diameter of the button. The synthetic density is a theoretical density calculated by mixing the density of glass and the density of the refractory filler in a predetermined volume ratio. Further, when the flow diameter is 16.6 to 17.5 mm, it means that the dimensional stability and the denseness are good under the tested firing conditions.

Cordierite prepares magnesium oxide, aluminum oxide, and optical stone powder in a molar ratio of 2MgO · 2Al ₂ O ₃ · 5SiO ₂ , mixes them, and fires them at 1400 ° C. for 10 hours. Thus, a powder having a predetermined particle size was obtained. Alumina having a commercially available average particle size of 5.0 μm was used.

Sample No. in Table 4 Nos. 1 to 5 have a softening point of 531 to 558 ° C., and the back glass substrate and the support frame can be firmly fused, and a dense support frame is formed at a temperature below the strain point (for example, 580 ° C.) of the glass substrate. Further, it can be determined that the support frame is not softened and deformed in the heat treatment step after the support frame is formed. Sample No. 1 to 5 had a thermal expansion coefficient of 74 to 84 × 10 ⁻⁷ / ° C. and had a thermal expansion coefficient suitable for high strain point glass and the like. Furthermore, sample no. In Nos. 1 to 5, the flow diameter is 17.0 to 17.3 mm under the firing conditions in the table, the evaluation of the devitrification state is good, and the support frame can be formed with high accuracy.

As is clear from the above description , the support frame forming material of the present invention is suitable for flat display devices, particularly fluorescent display tubes, PDPs, and FEDs.

It is a cross-sectional schematic diagram of the plate | board thickness direction of the flat display apparatus which concerns on this invention. (A) It is a cross-sectional schematic diagram of the plate | board thickness direction of the conventional flat display apparatus. (B) It is a cross-sectional schematic diagram of the plane direction of the conventional flat display apparatus, It is a cross-sectional schematic diagram of the plane direction which crossed in the dotted line direction of Fig.2 (a), and was seen from the front glass substrate side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Flat display apparatus 11 Front glass substrate 12 Back glass substrate 13 Support frame 14 Sealing glass

Claims (6)

A support frame forming material comprising glass powder and a refractory filler,
The mixing ratio of glass powder and refractory filler powder is 55 to 99% by volume of glass powder, 1 to 45% by volume of refractory filler powder,
The glass powder is expressed in mol% in terms of the following oxide, and the glass composition is SiO ₂ 5-30%, B ₂ O ₃ 25-45%, ZnO 20-60%, Al ₂ O ₃ 0-10%, R ₂ O 1-20% (however, R ₂ O indicates Li ₂ O, Na ₂ O, K ₂ O, Cs ₂ O), Li ₂ O 0-15%, Na ₂ O 0-15%, K _{2 O 0~ 4%, R'O 0~25} % ( however, R'O refers MgO, CaO, SrO, and BaO), 0~15% MgO, CaO 0~15%, BaO 0~15% , SrO 0 to 15%, ZrO ₂ + TiO ₂ 0 to 10%, and substantially no PbO. The glass powder is expressed in mol% in terms of the following oxide, and the glass composition is 7 to 25% SiO _2, 25 to 45% B ₂ O ₃ , 25 to 55% ZnO, 0 to 5% Al ₂ O ₃ , R ₂ O 5-15% (where R ₂ O refers to Li ₂ O, Na ₂ O, K ₂ O, Cs ₂ O), Li ₂ O 0-10%, Na ₂ O 0-10%, K _{2 O 0~ 4%, R'O 0~15} % ( however, R'O refers MgO, CaO, SrO, and BaO), 0~5% MgO, CaO 0~5%, BaO 0~10% , SrO _{0 to 5%,} the support frame forming material according to claim 1, ZrO _{2 +} containing TiO 2 0 to 7%, and substantially characterized in that it does not contain PbO.   The support frame forming material according to claim 1, wherein alumina is used as the refractory filler powder.   The support frame forming material according to any one of claims 1 to 3, wherein a softening point is 490 to 560 ° C. The support frame forming material according to claim 1, wherein a thermal expansion coefficient is 64 to 86 × 10 ⁻⁷ / ° C.   The support frame forming material according to claim 1, wherein the support frame forming material is used for a flat display device.