JP3793209B2 - Processing method of glass substrate of flat display - Google Patents

Description

  In the present invention, in order to promote the global environment, two substrates mainly composed of glass, that is, a face plate (front glass substrate) and a rear plate (rear glass substrate) are fritted via a frame. The present invention relates to a method for reproducing a face plate and a rear plate in a flat panel display having a structure hermetically bonded by glass or the like.

  Conventionally, most of household appliances to be discarded have been shredded, and after collection of valuable materials such as metal, the rest has been thrown into a “stable disposal site” where it is simply buried as an industrial waste in a digging hole.

  In recent years, environmental pollution caused by hazardous substances has become a problem as the capacity of disposal sites becomes serious. As an example, TV CRTs use a lot of leaded glass, but the Environmental Agency estimates that 20,000 tons of CRT is discarded every year, most of which is landfilled in stable disposal sites. It has been. However, it has been recognized that there is a risk that lead, which is a harmful substance, may diffuse because rainwater permeates in a stable state and there is no drainage facility. Under such circumstances, the review of conventional processing methods is urgently required. As for television CRTs, an empirical study has been conducted by the Japan Electrical Appliances Association that converts CRT glass into a cullet and reuses it again. Among them, a system has been developed in which a cathode ray tube is taken out from a television body and made into a glass cullet (see, for example, Non-Patent Document 1).

  For example, Patent Document 1 shows a method for collecting glass as cullet. Further, an example (Patent Document 2 or the like) is known in which a CRT glass is culleted (small glass piece) and reused in a CRT again. A method for separating the cathode ray tube from the face plate portion and the funnel portion for each material and culleting is disclosed in Patent Document 3 and the like. Further, Patent Document 4 discloses a method of regenerating the face plate after separating the cathode ray tube into a face plate portion and a funnel portion and peeling the phosphor and the black mask from the face plate portion.

  In order to reuse CRT glass, it is necessary to divide it into panel glass and lead funnel glass. This is because when a predetermined amount or more of lead is mixed into the panel glass, a browning phenomenon occurs, and thus the glass mixed with lead cannot be reused as a raw material for the panel glass. For that purpose, there is a process of separating the panel part and the funnel part first. For this, there is a method of defining and cutting the position (Patent Document 5) or frit glass that joins the panel part and the funnel part. A separation method (Patent Document 6) has been proposed.

  As a technique for separating the funnel portion and the panel portion fused with frit glass, for example, thermal distortion during heat treatment disclosed in publications such as Patent Document 7, Patent Document 8, Patent Document 9, and Patent Document 10 is used. A technique for separating the funnel part and the panel part is known.

  On the other hand, in recent years, research for applying cold cathode devices has been actively conducted. As the cold cathode device, a surface conduction type emission device, a field emission type device, a metal / insulating layer / metal type emission device, and the like are known, and electron emission can be obtained at a lower temperature than a hot cathode device. Therefore, a heater for heating is not required, the structure is simpler than that of a hot cathode element, and a fine element can be produced. Further, even if a large number of elements are arranged on the substrate at a high density, problems such as thermal melting of the substrate hardly occur. In addition, the hot cathode element operates by heating of the heater, so that the response speed is slow. In the case of the cold cathode element, there is an advantage that the response speed is fast.

  Among the cold cathode devices, particularly the surface conduction electron-emitting device has an advantage that a large number of devices can be formed over a large area because of its simple structure and easy manufacture. Thus, for example, as disclosed in Patent Document 11 by the present applicant, a method for arranging and driving a large number of elements has been studied.

  As for the application of the surface conduction electron-emitting device, for example, image forming apparatuses such as an image display apparatus and an image recording apparatus, and a charged beam source have been studied.

  In particular, as an application to an image display device, for example, as disclosed in Patent Document 12, Patent Document 13, or Patent Document 14, a surface conduction electron-emitting device and a phosphor that emits light when irradiated with an electron beam are combined. The image display device used is studied. An image display device using a combination of a surface conduction electron-emitting device and a phosphor is expected to have characteristics superior to those of other conventional image display devices. For example, it can be said that it is superior in that it does not require a backlight and has a wide viewing angle as compared with a liquid crystal display device that has been widespread in recent years.

  Further, for example, Patent Document 15 discloses a method for driving a large number of field emission elements. As an example of applying the FE type to an image display device, for example, R.I. A flat display reported by Meyer et al. Is known (Non-Patent Document 2).

  An example in which a large number of metal / insulating layers / metal emitting elements are arranged and applied to an image display device is disclosed in, for example, Patent Document 16.

  Among the image forming apparatuses using the electron-emitting devices as described above, a flat display with a small depth is attracting attention as a replacement for a CRT type display device because it is space-saving and lightweight. Further, the inside of the airtight container in the image forming apparatus is maintained at a vacuum of about 10 to the sixth power of Torr, and as the display area of the image display apparatus becomes larger, the airtight container has a pressure difference between the inside and the outside. A means for preventing deformation or destruction of the rear plate and the face plate is required. The method of increasing the thickness of the rear plate and the face plate not only increases the weight of the image display device, but also causes image distortion and parallax when viewed from an oblique direction. On the other hand, a spacer made of a relatively thin glass plate and having a conductive film for preventing charging on the surface is generally provided. In addition to the field emission electron source display (FED) and MIM type display described above, flat displays including a fluorescent display (VFD), a plasma display (PDP), a surface conduction electron source display (SED), etc. Due to its space and light weight, it has been attracting attention as a replacement for CRT type display devices, and much research and development has been conducted.

  For example, the present applicant has made several proposals regarding an electron source in which a large number of surface conduction electron-emitting devices, which are a kind of cold-cathode electron-emitting devices, are arranged on a substrate, and an image display apparatus using the electron source. .

  The configuration of the surface conduction electron-emitting device and the configuration of an image display device using the surface-conduction electron-emitting device are described in detail in, for example, Patent Document 17, and will be briefly described.

  FIGS. 8A and 8B show an example of the configuration of the surface conduction electron-emitting device. Reference numeral 411 denotes a substrate, reference numerals 412 and 413 denote a pair of element electrodes, and reference numeral 414 denotes a conductive film, which has an electron emission portion 415 in a part thereof, and constitutes an electron emission element 416.

  As a method of forming the electron emitting portion 415, a method is employed in which a voltage is applied between the pair of element electrodes 412 and 413 to deform, alter or destroy a part of the conductive film to increase resistance. This is referred to as “energization forming process”. In order to form an electron emission portion having good electron emission characteristics by this method, the conductive film is preferably composed of conductive fine particles. Examples of the material include PdO fine particles. The voltage applied in the energization forming process is preferably a pulse voltage. The method of applying a pulse having a constant peak value as shown in FIG. 9A or the peak value gradually increasing as shown in FIG. 9B. Any method of applying a pulse to be applied can be applied.

  In order to form the conductive fine particle film, it is possible to deposit the conductive fine particles directly by the gas deposition method, but a solution of a compound (for example, an organometallic compound) containing the constituent elements of the conductive film is applied. A method of forming a desired conductive film by heat treatment or the like is a preferable method because it does not require a vacuum apparatus, is inexpensive to manufacture, and is easily applied to form a large electron source. In addition, as a method of applying the organometallic compound solution, a method of applying only to a necessary portion using an ink jet apparatus is more desirable because it does not require an extra step for patterning the conductive film. is there.

  After forming the electron emission part, by applying a pulse voltage between the device electrodes in an appropriate atmosphere containing an organic substance (referred to as “activation treatment”), carbon is formed in and near the electron emission part. A deposited film having a main component is formed, the current flowing through the element is increased, and the electron emission characteristics are also improved.

  Next, a step called “stabilization treatment” is preferably performed. This is a process of stabilizing the characteristics of the electron-emitting device by sufficiently removing organic substances by continuing to exhaust while heating the vacuum vessel and the electron-emitting device.

  A method of forming such a conductive film of an electron source using a surface conduction electron-emitting device using an ink jet apparatus is disclosed in Patent Document 18 and the like.

  The ink jet apparatus will be briefly described. There are roughly two types of ink ejection methods for inkjet devices. The first method is a method of ejecting liquid droplets by the contraction pressure of a piezo element disposed in a nozzle, and is called a piezo jet method. In this system, a conductive thin film material is stored in an ink reservoir, and a predetermined voltage is applied to an electric signal input terminal, whereby the cylindrical piezo contracts and discharges liquid as droplets.

  The second method is a method in which a liquid is heated and foamed by a heating resistor, and droplets are ejected thereby, which is called a bubble jet (registered trademark of Canon Inc.) method. In the ink jet apparatus using the bubble jet method, the heating resistor generates heat, the liquid is foamed, and droplets are discharged from the nozzle.

  Using the ink jet apparatus as described above, a solution of an organometallic compound is applied as a droplet only at a predetermined position and dried, and then the organometallic compound is thermally decomposed by a heat treatment, so that a metal or a metal oxide, etc. A conductive film made of the fine particles is formed. FIG. 1 shows an example of the configuration of the image display apparatus. In FIG. 1, 1 is a rear plate, 2 is a face plate in which a fluorescent film 2b and a metal back 2c are formed on the inner surface of a substrate 2a, 3 is a support frame, and the rear plate 1, support frame 3 and face plate 2 are The image display device 15 is configured by sealing and sealing with frit glass.

The flat panel display configured as described above is expected to increase in size and increase in production in the future. In addition, for these flat panel displays, the frit glass used for sealing contains lead, and the phosphor 2b and the spacer 4 that form the image forming member are high-cost members. As in the case of glass, the establishment of a recovery system is an important issue in terms of “detoxification”, “volume reduction”, and “recycling”.
Japanese Patent Laid-Open No. 61-50688 JP-A-9-193762 JP 05-185064 A Japanese Patent Application Laid-Open No. 7-037509 JP-A-9-115449 JP-A-7-45198 JP-A-5-151898 JP 7-029496 A Japanese Patent Laid-Open No. 9-200654 Japanese Patent Laid-Open No. 9-200657 Japanese Patent Application Laid-Open No. 64-31332 US Pat. No. 5,066,883 JP-A-2-257551 JP-A-4-28137 U.S. Pat. No. 4,904,895 JP-A-3-55738 JP 7-235255 A JP-A-8-273529 "Electronic Technology" November, 1997 issue R. Meyer: "Recent Development on Micro-tips Display at LETI", Tech. Digest of 4th Int. Vacuum Micro-electronics Conf., Nagahama, pp. 6-9 (1991)

  When the substrate glass is reused, the rear plate 1 and the face plate 2 are separated from other members. And after removing the wiring and elements formed on the substrate and returning it to the state of a single glass, it can be reused as it is, or once culleted and newly used as a glass for the substrate or as a raw material for other products It can be reused.

  However, as described above, materials such as wiring, electron-emitting devices, and frit glass are formed on the glass substrate, and when blue plate glass is used as the substrate as described above, a thin film is formed on the surface in advance. Sometimes it is. Some of these materials have extremely high adhesion to the glass substrate, or some elements may gradually diffuse into the glass substrate, making it difficult to completely separate from the substrate glass. There is something wrong.

  Further, when the used glass is culleted once and then reused, if elements other than the glass constituent elements are mixed in the culleted glass, the physical properties and color of the glass are affected. Therefore, glass mixed with impurity elements may not be reused. Even when the substrate is reused as it is, it is desired to restore the state as close to the initial glass substrate as possible.

  In view of such circumstances, an object of the present invention is to provide a method of processing a glass substrate of a flat display that realizes effective and efficient reuse of substrate glass.

  The flat display glass substrate processing method of the present invention is a flat display glass substrate processing method including a rear plate and a face plate, which are hermetically bonded to each other, and after separating the rear plate and the face plate, A detection step of detecting elements existing on the surface of the glass substrate by irradiating the surface of the glass substrate constituting the rear plate or the glass substrate constituting the face plate with primary X-rays and detecting the generated fluorescent X-rays; And a removal step of removing elements other than the elements constituting the glass substrate from the surface of the glass substrate by polishing the glass substrate in accordance with the detection result of the detection step.

  Moreover, in the processing method of the glass substrate of the flat display of this invention, in the detection process which detects the element which exists on the surface of a glass substrate, the detector which detects a glass substrate and a fluorescent X ray according to the magnitude | size of a glass substrate. The relative position of is changed.

  Moreover, in the processing method of the glass substrate of the flat display of this invention, the detector which detects a fluorescent X-ray irradiates a primary X-ray to the area | region wider than the area | region which can detect a fluorescent X-ray. .

  Moreover, in the processing method of the glass substrate of the flat display of this invention, the incident angle at the time of making a primary X-ray inject into a glass substrate is an angle below the critical angle of a primary X-ray.

  Moreover, in the processing method of the glass substrate of the flat display of this invention, the detection process and removal process with respect to the surface of a glass substrate are repeatedly performed.

  Further, in the processing method of the glass substrate of the flat display of the present invention, a plurality of electron-emitting devices are disposed on the rear plate, and an image display unit is disposed on the face plate. Are joined via a support frame so as to face each other.

  Moreover, in the processing method of the glass substrate of the flat display of this invention, the wiring which has Ag as a main component is formed on the glass substrate in the rear plate.

  Moreover, in the processing method of the glass substrate of the flat display of this invention, the thin film containing elements other than the element which comprises a glass substrate is formed in the surface of the glass substrate which comprises a rear plate, It is characterized by the above-mentioned.

  Further, in the method for processing a glass substrate of the flat display of the present invention, these members are separated by melting frit glass for joining the rear plate, the face plate and the support frame. .

  According to the present invention, it is possible to detect residues on the surface of a glass substrate by a simple method, particularly in the process of treating used substrate glass, and to remove all elements other than glass constituent elements. This makes it possible to reuse the glass without waste.

  According to the present invention, residues on the substrate surface and elements diffused inside the substrate can be detected by a simple method, and all the elements other than these glass constituent elements can be removed, so that the glass is wasted. And can be reused efficiently.

  Next, the best mode of the present invention will be described with reference to the drawings. Here, it is assumed that the flat panel display having the structure shown in FIG. 1 is disassembled.

  FIG. 2 is a flowchart showing the steps of the dismantling method in this embodiment. First, after removing wires, terminals and the like from the flat panel display (S60) taken out from the housing (S61), the internal vacuum is released, and then the exhaust pipe is removed (S62). Next, it is separated into constituent members such as a face plate (S64), a rear plate (S70), and a frame portion (S63). As the frit glass in which these parts are welded, a low melting glass mainly composed of lead oxide is generally used. As the separation method, a method such as melting of the frit glass by heating or melting of the frit glass by an appropriate solvent can be used.

  The separated face plate (S64) is removed with phosphors, black bodies and metal backs by an appropriate method (S65), and then washed with a solvent such as nitric acid and water to remove residual frit glass and clean the glass surface. (S66). On the other hand, a part or all of the constituent material formed on the substrate can be removed by performing an appropriate solvent and water washing process on the rear plate (S70) after separation (S71, S72).

  Next, the elements present on the surface of the glass substrate after the removal process as described above are detected.

  FIG. 3 is a schematic view showing an X-ray fluorescence analyzer according to the present invention for detecting elements present on the glass surface. In FIG. 3, 301 is a support for a glass substrate 302, 302 is a glass substrate as a sample, 303 is an X-ray light source, 304 is a monochromator, 305 is primary X-ray, 306 is fluorescent X-ray, and 307 is a semiconductor detector. , 308 is a cooling device, 309 is a preamplifier, 310 is an amplifier, 311 is a multi-channel analyzer, and 312 is a computer.

  The element is detected by the following procedure. First, the primary X-ray 305 emitted from the X-ray light source 303 is monochromatic by the monochromator 304 and then incident on the surface of the glass substrate 302 on the support base 301 at an angle θ. The X-ray light source has energy that can excite an element present on the glass substrate 302. For example, W-Lα line, Au-Lα line, Mo-Kα line, etc. are used. Fluorescent X-rays are generated from the surface of the glass substrate 302 irradiated with the primary X-rays 305 and detected by the semiconductor detector 307 installed above the glass substrate 302. A Si (Li) semiconductor detector is used as the detection element. The detection signal from the semiconductor detector 307 is processed by the computer 312 after passing through the preamplifier 309, the amplifier 310, and the multi-channel analyzer 311 to obtain a signal intensity corresponding to the type and concentration of the surface element of the glass substrate 302. The semiconductor detector 307 and the preamplifier 309 are cooled by liquid nitrogen.

Here, when the incident angle θ of the primary X-ray 305 is set to an angle at which the X-ray causes total reflection, that is, a low angle equal to or less than the total reflection critical angle, the X-ray penetrates only about several nm from the sample surface, and X-ray fluorescence is generated efficiently. Therefore, extremely sensitive elemental analysis with a detection lower limit of about 10 ⁹ atoms / cm ² can be performed in the region of the sample surface of several nm or less. The total reflection critical angle can be obtained by θc≈1.64 × 10 ⁵ × ρ ^1/2 × λ (ρ: substrate density (g / cm 3), λ: X-ray wavelength (cm)).

  By the way, the glass substrate 302 in this embodiment is large and has a size of several tens of cm on one side. The present invention intends to perform such a large area elemental analysis efficiently and at low cost. In order to measure with high sensitivity by the above method, it is generally preferable to bring the detector as close to the sample surface as possible. In this case, the analysis region substantially depends on the aperture of the detector, and is usually about 10 mmφ. However, when measuring in a state where the sample and the detector are brought close to each other in this way, it is necessary to scan the sample to obtain a large number of data or to arrange a large number of detectors when measuring a wide area. Become. Therefore, much time and equipment costs are required as it is.

  Therefore, in the present invention, a method of changing the relative position of the sample surface and the detector according to the size of the substrate is used in order to efficiently perform elemental analysis without sacrificing sensitivity. Next, a method for changing the relative position in the present invention will be described with reference to FIG.

  In FIG. 4, reference numeral 301 denotes a support for a glass substrate 302, 302 a glass substrate as a sample, 307 a semiconductor detector, 314 a semiconductor element, 315 an X-ray transmission window, and 316 a collimator. The configuration of the semiconductor detector 307 is as shown in the figure. The semiconductor element 314 has an angle φ determined from the area indicated by the dotted line, that is, the size of the X-ray transmission window 315, the relative position with respect to the semiconductor element 314, and the like. X-rays in a region having a spread depending on the size l of the semiconductor element 314 itself can be received.

  When the semiconductor detector 7 is brought close to the sample surface as shown in FIG. 4A, the analysis region is substantially the same as the diameter of the X-ray transmission window 315. On the other hand, when the position of the semiconductor detector 307 is moved away from the sample surface to the state shown in FIG. 4B, the X-ray intensity detectable from the unit area decreases, but the detectable region increases. Therefore, when detecting fluorescent X-rays from the glass substrate 302 having a length L on one side, the distance d between the glass substrate 302 and the semiconductor detector 307 is set so that 2d · tanφ> L, and the entire surface of the glass substrate 302 is set. By measuring while irradiating primary X-rays, X-rays from the entire glass substrate 302 can be captured without sacrificing sensitivity as a result.

  In order to irradiate a desired region with X-rays, the beam diameter of the primary X-ray is based on a> W · sin θ from the region W to be irradiated and the incident angle θ of the primary X-ray as shown in FIG. What is necessary is just to determine a. If the glass substrate 302 is extremely large and it is difficult to secure the distance d according to the size, it can be performed by dividing the glass substrate 302 into a plurality of regions and repeating the measurement.

  The X-ray transmission window 315 of the semiconductor detector 307 is preferably a rectangle close to the shape of the glass substrate 302. For example, FIG. 6 shows the difference in the fluorescent X-ray detection region when the shape is a circle (FIG. 6A) and when the shape is similar to the glass substrate 302 (FIG. 6B). In FIG. 6, 302 is a glass substrate (viewed from above), and a dotted line or a dot display part is an X-ray detection area. When the X-ray transmission window 315 is circular, the shape with the glass substrate 302 does not match, so that the detection efficiency is not necessarily high. On the other hand, in the case of FIG. 6B, X-rays can be detected efficiently. Although the aspect ratio of the glass substrate 302 is not necessarily constant, a more efficient detection process can be performed by selecting an appropriate shape of the transmission window from the type and amount of use. By detecting fluorescent X-rays generated from the surface of the glass substrate 302 by such a method, the presence or absence of residual elements on the substrate surface or elements diffusing into the substrate, the presence or absence of a thin film formed on the substrate surface, etc. Can know.

  If an element other than the glass constituent element is detected in the above steps, a step of removing it is subsequently performed. As a removing method in this case, various methods can be used, and surface polishing of the glass substrate 302 is particularly preferable.

  FIG. 7 is a schematic view showing an example of a polishing apparatus according to the present invention. In FIG. 7, 327 is a support base for the glass substrate 328, 328 is a glass substrate, 329 is a polishing tool, 330 is a rotation support bar, 331 is a support arm, 332 is a motor, 333 is a support column, and 334 is a polishing surface. The glass substrate 328 to be polished is placed on the support base 327 with the polishing surface facing upward, and a polishing tool 329 is pressed against the polishing surface. The rotation support rod 330 and the polishing tool 329 are rotated by the operation of the motor 332, and a slurry containing an abrasive such as cerium oxide is supplied to the polishing surface 334, whereby the glass surface 334 is polished.

  The polished glass substrate 328 is washed and then subjected to the elemental analysis described above again. Thus, element detection and polishing of the glass surface 334 are repeated until no element other than the glass constituent elements of the glass substrate 328 is finally detected. The glass substrate 328 after the above steps can be used as it is or culleted and reused as a raw material for a flat display substrate or other products through a remelting step.

  Hereinafter, the present invention will be described in more detail with reference to examples. In the following embodiments, the matrix drive type surface conduction electron source display having the structure shown in FIG. 1 is disassembled.

  In Example 1, quartz glass of 80 mm × 800 mm × 2.8 mm is used as the face plate 2 and the rear plate substrate. The rear plate is formed with a cold cathode element 11 containing Pd as a main component, a wiring 12 containing Ag as a main component, an electrode made of Pt, and the like on a substrate. The body, the metal back 2c, etc. are formed. A disassembly processing method for the display having such a configuration will be described with reference to FIGS. 3, 4, 7, and 1.

  [1] The housing part was disassembled, and the part where the rear plate 1, the face plate 2, and the frame 3 were welded with frit glass was taken out.

  [2] The rear plate 1, the face plate 2, and the frame 3 parts were immersed in a 0.2N nitric acid solution to gradually dissolve the welded parts, and the respective parts were separated.

  [3] After the physical scraping work of the components formed on the rear plate 1 and the face plate 2, it was immersed again in a 0.2 N nitric acid solution and subjected to ultrasonic vibration. Thereafter, the rear plate 1 and the face plate 2 were washed with pure water to remove the frit glass and other dissolved matters remaining on the substrate.

  [4] Next, the elements present on the substrate surface were detected with a fluorescent X-ray analyzer as shown in FIG. An Au-Lα ray (λ = 0.12764 nm) was used as the X-ray light source, and the incident angle θ of the X-ray on the substrate was not less than the total reflection angle critical angle. Further, X-rays having a beam width of 0.15 mm or more and a depth of 80 mm or more shown in FIG. 5 were irradiated so that the entire surface of the glass substrate was irradiated with X-rays. The shape of the X-ray transmission window was a square, and the distance d between the glass substrate and the detector shown in FIG. 4 was set to 40 mm.

  Thus, when fluorescent X-rays generated from the entire surface of the glass substrate were captured for 200 seconds and the elements were measured, Pt and Ag were detected from the rear plate substrate in addition to Si as a substrate element. No elements other than Si were detected from the faceplate substrate.

  [5] Next, the surface of the rear plate substrate on which Pt and Ag were detected was polished by the polishing apparatus shown in FIG. The polishing tool 325 was pressed against the polishing surface of the substrate, the polishing tool was rotated, and the entire substrate was polished for 5 minutes while applying a cerium oxide slurry having an average particle size of 10 microns.

  [6] After the polished rear plate substrate was washed with pure water, the elemental analysis described above was performed again. As a result, Pt and Ag were below the detection limit, and it was confirmed that all the residues on the substrate could be removed.

  [7] The rear plate substrate that has completed the above steps could be reused as a substrate without being culleted together with the face plate substrate that did not require a polishing step.

In Example 2, a blue plate glass of 80 mm × 800 mm × 2.8 mm is used as the face plate substrate, and a blue plate glass of the same size is laminated as the rear plate substrate with a 100 nm SiO ₂ thin film. The rear plate has a cold cathode element 11 mainly composed of Pd on the substrate, wirings 12 and 13 mainly composed of Ag, electrodes made of Pt, and the like, and the face plate has phosphor and black on the substrate. A body and a metal back are formed. The dismantling method for such a display will be described below.

  First, the rear plate, the face plate, and the frame portion were separated by the same method as the steps [1] to [3] in Example 1, and then a part of the constituent material of the element formed on the substrate was removed.

  [4] Next, the elements present on the substrate surface were detected. In this embodiment, Au-Lα rays (λ = 0.12764 nm) were used as the X-ray light source, and the incident angle θ of the X-rays on the substrate was set to 0.1 ° which is equal to or less than the total reflection angle critical angle. Further, X-rays having a beam width of 0.15 mm or more and a depth of 80 mm or more shown in FIG. 5 were irradiated so that the entire surface of the glass substrate was irradiated with X-rays. The shape of the X-ray transmission window was a square, and the distance d between the glass substrate and the detector shown in FIG. 4 was set to 40 mm.

  Thus, fluorescent X-rays generated from the entire surface of the glass substrate were captured for 200 seconds and subjected to elemental analysis. As a result, Pt, Ag and Pb were detected in addition to the substrate constituent elements from the rear plate substrate. In addition to the elements constituting the substrate, Pb was also detected from the faceplate substrate.

  [5] Next, the surfaces of the rear plate and the face plate substrate were polished by the polishing apparatus shown in FIG. The polishing tool 329 was pressed against the polishing surface of the substrate, the polishing tool was rotated, and the entire substrate was polished for 5 minutes while applying a cerium oxide slurry having an average particle size of 10 microns.

  [6] After the polished rear plate substrate was washed with pure water, the elemental analysis described above was performed again. As a result, Pt and Pb were below the detection limit, but Ag was still detected although the intensity decreased. On the other hand, no elements other than the constituent elements of the substrate were detected from the faceplate substrate.

  [7] The surface of the rear plate substrate was again polished by the polishing apparatus shown in FIG. The entire substrate was polished for 15 minutes by the same method as in the step [5].

  [8] After the polished rear plate substrate was washed with pure water, the elemental analysis described above was performed again. As a result, no elements other than the constituent elements of the substrate were detected, and it was confirmed that all the residues on the substrate and the diffusing elements could be removed in the substrate.

  [9] The rear plate and the face plate substrate after the above steps were culleted and reused as a flat display substrate after a melting step.

  In Example 3, quartz glass of 300 mm × 250 mm × 2.8 mm is used as the face plate and rear plate substrate. Except for this point, a disassembly processing method will be described for a flat display having the same configuration as in the first embodiment.

  First, after separating the rear plate, the face plate, and the frame by the same method as in the steps [1] to [3] in Example 1, a part of the constituent material of the element formed on the substrate in the nitric acid solution Was removed.

  [4] Next, an element present on the substrate surface was detected with a total reflection X-ray fluorescence spectrometer as shown in FIG. In this example, Au-Lα ray (λ = 0.12764 nm) was used as the X-ray light source, and the incident angle θ of the X-ray on the substrate was set to 0.1 °. Further, X-rays having a beam width of 0.6 mm or more and a depth of 300 mm or more shown in FIG. 5 were irradiated so that the entire surface of the glass substrate was irradiated with X-rays. The shape of the X-ray transmission window was a square, and the distance d between the glass substrate and the detector shown in FIG. 4 was set to 150 mm.

  As a result of capturing the fluorescent X-rays generated from the surface of the glass substrate in this manner for 200 seconds and performing elemental analysis, Pt and Ag were detected from the rear plate substrate in addition to Si as a substrate element. No elements other than Si were detected from the faceplate substrate.

  Subsequently, the glass surface was polished by the same method as the steps [5] to [7] in Example 1 to remove all residues on the substrate. The rear plate substrate that has undergone the above steps could be reused as a substrate without being culleted together with the face plate substrate that did not require a polishing step.

In Example 4, a rear plate substrate in which 300 μm × 250 mm × 2.8 mm blue plate glass is laminated with 1 μm of P ₂ doped SiO ₂ thin film is used. Except for this point, a disassembly processing method will be described for a flat display having the same configuration as that of the first embodiment.

  First, after separating the rear plate, the face plate, and the frame by the same method as in the steps [1] to [3] of Example 1, a part of the constituent material of the element formed on the substrate in the nitric acid solution Was removed.

  [4] Next, an element present on the substrate surface was detected with a total reflection X-ray fluorescence spectrometer as shown in FIG. In Example 4, Mo-Kα rays (λ = 0.07107 nm) were used as the X-ray light source, and the incident angle θ of the X-rays on the substrate was set to 0.1 °. Further, X-rays having a beam width of 0.6 mm or more and a depth of 300 mm or more shown in FIG. 5 were irradiated so that the entire surface of the glass substrate was irradiated with X-rays. The shape of the X-ray transmission window was a square, and the distance d between the glass substrate and the detector shown in FIG. 4 was set to 150 mm.

  Thus, when fluorescent X-rays generated from the surface of the glass substrate were captured for 200 seconds and elemental analysis was performed, Si, P, Pt, Ag and Pb were detected from the rear plate substrate. In addition to the substrate constituent elements, Pb was detected from the faceplate substrate.

  [5] Next, the surfaces of the rear plate and the face plate substrate were polished by the polishing apparatus shown in FIG. The polishing tool 329 was pressed against the polishing surface of the substrate, the polishing tool was rotated, and the entire substrate was polished for 5 minutes while applying a cerium oxide slurry having an average particle size of 10 microns.

  [6] After the polished rear plate substrate was washed with pure water, the elemental analysis described above was performed again. As a result, Pt, Ag and Pb were below the detection limit, and only Si and P were detected. On the other hand, no elements other than the constituent elements of the substrate were detected from the faceplate substrate.

  [7] The surface of the rear plate substrate was again polished by the polishing apparatus shown in FIG. The entire substrate was polished for 10 minutes by the same method as [5].

[8] After the polished rear plate substrate was washed with pure water, the elemental analysis described above was performed again. As a result, while P was below the detection limit, glass constituent elements such as K and Ca were detected. As a result, it was confirmed that the SiO ₂ layer doped with P was removed and that all the residues on the substrate were removed.

  [9] The rear plate substrate and face plate substrate after the above steps were culleted, and after a melting step, could be reused as a flat display substrate.

  Here, an example will be described in which an electron source substrate is formed by forming a large number of surface conduction electron-emitting devices on a glass substrate treated by the method of the present invention, and an image forming apparatus is manufactured using the electron source substrate.

  First, Pt electrodes are formed in a matrix shape on a glass substrate after regeneration using a vacuum film formation technique and a photolithography technique. Here, the interval between the element electrodes is 20 μm, the width of each element electrode is 500 μm, the thickness is 100 nm, and the arrangement pitch of the elements is 1 mm. Subsequently, wiring made of Ag is formed in a matrix by a printing method.

  Next, a palladium acetate monoethanolamine aqueous solution is spin-coated with a spinner between the device electrodes, and a heating and baking process is performed at 270 ° C. for 10 minutes. A thin film composed of palladium oxide (PdO) fine particles was obtained. Thereafter, a conductive thin film having a width of 300 μm was obtained by photolithography and dry etching.

  Next, a forming process is performed by applying a voltage between the device electrodes in a vacuum to form a crack-shaped electron emission portion in the conductive thin film.

  Next, an activation process is performed on the element for which energization forming has been completed. In this embodiment, ethylene gas is introduced into the vacuum, and a pulse voltage having a peak value of 20 V is repeatedly applied between the device electrodes for 30 minutes. By this activation process, a compound mainly composed of carbon was deposited in the vicinity of the electron emission portion by about 10 nm.

  The electron source substrate on which a large number of surface conduction electron-emitting devices are formed in this way was used as a rear plate, and an envelope was formed by the face plate and the support frame. The inside of the envelope was evacuated and sealed to produce an image forming apparatus having a display panel and a drive circuit for performing television display. In this image forming apparatus, a very good image without a non-light emitting portion (pixel defect) is formed.

It is a perspective view of the display apparatus using a spacer. It is a flowchart which shows the dismantling process process of the flat display of this invention. It is a schematic diagram which shows the fluorescent X-ray-analysis apparatus which detects the element which exists on the glass substrate surface of this invention. It is a schematic diagram which shows the relative position of the sample surface and detector in the total reflection X-ray fluorescence spectrometer of the present invention. It is a schematic diagram which shows the irradiation area | region of the primary X-ray in the total reflection fluorescent-X-ray-analysis apparatus of this invention. It is a schematic diagram which shows the detection area | region of the fluorescent X-ray in the total reflection X-ray fluorescence analyzer of this invention. It is a schematic diagram which shows the grinding | polishing apparatus of the glass substrate surface of this invention. It is the top view and sectional drawing of the electron-emitting element which can be used for this invention. It is an applied voltage waveform figure at the time of forming of the electron-emitting element used for this invention.

Explanation of symbols

1 Rear plate 2 Face plate 2a Glass substrate (face plate substrate)
2b Fluorescent screen 2c Metal back 3 Frame 4 Spacer 11 Surface conduction electron source 12 X-direction element wiring (upper wiring)
13 Y-direction element wiring (bottom wiring)
15 Image display device 301 Glass substrate support 302 Glass substrate 303 X-ray light source 304 Monochromator 305 Primary X-ray 306 Fluorescent X-ray 307 Semiconductor detector 308 Cooling device 309 Preamplifier 310 Amplifier 311 Multichannel analyzer 312 Computer 313 Primary X Line incident angle 314 Semiconductor element 315 X-ray transmission window 316 Collimator 327 Glass substrate support base 328 Glass substrate 329 Polishing tool 330 Rotating support rod 331 Support arm 332 Motor 333 Support column 334 Polishing surface

Claims (9)

A method of processing a glass substrate of a flat display including a rear plate and a face plate, hermetically bonded to each other ,
After separating the rear plate and the face plate, the surface of the glass substrate constituting the rear plate or the glass substrate constituting the face plate is irradiated with primary X-rays, and the generated fluorescent X-rays are detected. a detection step of detecting an element present on the surface of the glass substrate by,
Depending on the detection result of the detecting step, a flat display, wherein said element from the surface other than the elements constituting the glass substrate of the glass substrate, having a removal step of removing by polishing the glass substrate Glass substrate processing method. In the detection step of detecting an element present on the surface of the glass substrate,
The glass substrate according to the size, processing method for a glass substrate of a flat display according to claim 1, characterized in that to change the relative position of the detector for detecting the fluorescent X-ray and the glass substrate. 2. The method for processing a glass substrate of a flat display according to claim 1, wherein the detector that detects the fluorescent X-rays irradiates a primary X-ray on a region wider than a region where the fluorescent X-ray can be detected. . The method for processing a glass substrate of a flat display according to claim 1, wherein an incident angle when primary X-rays are incident on the glass substrate is an angle equal to or smaller than a critical angle of primary X-rays. The method for processing a glass substrate of a flat display according to any one of claims 1 to 4 , wherein the detecting step and the removing step for the surface of the glass substrate are repeatedly performed. A plurality of electron-emitting devices are disposed on the rear plate , an image display unit is disposed on the face plate, and a support frame is provided so that the rear plate and the face plate are disposed to face each other. processing method for a glass substrate of a flat display according to any one of claims 1 to 5, characterized in that it is joined Te. The method for processing a glass substrate of a flat display according to claim 6 , wherein in the rear plate, a wiring mainly composed of Ag is formed on the glass substrate. Wherein the surface of the glass substrate constituting the rear plate, the processing method for a glass substrate of a flat display according to claim 6, characterized in that it is a thin film formed containing an element other than the elements constituting the glass substrate. 7. The flat display glass substrate according to claim 6 , wherein frit glass for joining the rear plate, the face plate, and the support frame is melted to separate these members. Processing method.

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