JP5649216B2 - Method for manufacturing plasma display panel - Google Patents

Description

  The present invention relates to a method for manufacturing a plasma display panel (hereinafter also referred to as PDP), and more particularly to a method for manufacturing a front plate and a back plate for forming an AC drive type PDP.

  An example of the configuration of an AC surface discharge type PDP, which is a typical AC drive type PDP, is shown in FIGS. FIG. 14 is a perspective view showing a part of the PDP in a state where the front plate 1 and the back plate 8 are separated. FIG. 15 shows a state in which the front plate 1 and the back plate 8 of FIG. 14 are combined, and is a cross-sectional view along the direction crossing the scan electrode 3 and the sustain electrode 4 in FIG.

  The front plate 1 has a configuration in which display electrode pairs 5 including scan electrodes 3 and sustain electrodes 4 that perform surface discharge are arranged in parallel on the surface of a transparent and insulating front substrate 2. Scan electrode 3 and sustain electrode 4 are each composed of transparent electrodes 3a, 4a and bus electrodes 3b, 4b formed thereon. A front dielectric layer 6 is formed so as to cover the display electrode pair 5, and a protective film 7 is formed thereon.

  On the other hand, the back plate 8 has a configuration in which address electrodes 10 for writing image data are arranged on the surface of a transparent and insulating back substrate 9 and the upper part thereof is covered with a back dielectric layer 11. On the back dielectric layer 11, ribs 12 are formed, which are formed of, for example, low melting point glass and form partition walls. The ribs 12 have a cross beam shape formed by vertical ribs 12a formed extending in a direction parallel to the address electrodes 10 and horizontal ribs 12b formed in a direction orthogonal thereto. Each pixel is defined by a region surrounded by the vertical ribs 12a and the horizontal ribs 12b. A red phosphor layer 13r, a green phosphor layer 13g, and a blue phosphor layer 13b corresponding to the address electrodes 10 are formed on the side surfaces of the ribs 12 and the surface of the back dielectric layer 11 in each pixel region by coating. Has been.

  The front plate 1 and the back plate 8 face each other so that the display electrode pair 5 and the address electrode 10 are orthogonal to each other to form a matrix. A space surrounded by the vertical ribs 12a and the horizontal ribs 12b between the front plate 1 and the back plate 8 is a discharge space 14 of each pixel. Corresponding to each discharge space 14, the display electrode pair 5 and the address electrode 10 are three-dimensionally crossed to form a discharge cell 15. A black stripe 16 is formed between the display electrode pair 5 of the front plate 1 so as to face the upper portion of the lateral rib 12b.

  The front plate 1 and the back plate 8 are sealed with a sealing material such as glass frit (not shown) in the outer peripheral region of the surfaces facing each other, and the discharge space 14 is mixed with neon (Ne) and xenon (Xe). The discharge gas which consists of gas is enclosed. For example, a discharge gas having a Xe ratio of 10% is used, and the discharge gas is sealed at a pressure of about 450 Torr (about 60 kPa).

  In the AC drive type PDP having such a configuration, the front dielectric layer 6 formed on the display electrode pair 5 exhibits a specific current limiting function. The front dielectric layer 6 needs to be formed after the formation of the display electrode pair 5 and the black matrix 16 and so as to reliably cover them. Therefore, the front dielectric layer 6 is generally formed by printing and baking a low melting point glass layer. The protective film 7 is provided to prevent the front dielectric layer 6 from being sputtered by plasma discharge, and is required to be a material excellent in sputtering resistance. Furthermore, for the purpose of lowering the discharge voltage, MgO, which is an active material, is used as the material of the protective film 7. Further, active materials such as CaO, SrO, and SrCaO may be used as the material for the protective film 7.

  When the active material as described above is used as the material of the protective film 7, if the protective film 7 is formed on the front plate 1 and then exposed to the atmosphere, it is affected by water and carbon dioxide in the atmosphere. The physical properties change immediately and the discharge voltage rises. That is, water and carbon dioxide in the atmosphere are adsorbed and absorbed, resulting in hydroxylation and carbonation. In order to suppress this, a method has been proposed in which the steps from the deposition of the protective film 7 to the panel sealing with a sealing material are performed in a vacuum atmosphere or an inert gas atmosphere. However, in actual display production, performing a process from the deposition of a protective film to sealing with a sealing material in a vacuum atmosphere has a very high barrier in terms of production tact and device cost.

  Thus, as another method for suppressing deterioration of the protective film, Patent Document 1 discloses a method of sealing a panel using a laser before the protective film absorbs gas from the atmosphere. That is, by locally heating the sealing material with a laser, the sealing time can be shortened, and the characteristic deterioration of the protective film can be avoided.

JP 2008-166197 A

  However, the above method disclosed in Patent Document 1 has the following problems.

  (1) The first problem is that panel cracks due to residual stress are likely to occur when the usage period is long. When the panel is sealed by locally heating the sealing material with a laser, a large stress is applied between the sealing material and the bonding surface, and a residual stress is generated. Due to the residual stress, the possibility of panel cracking increases over time.

  More specifically, when the sealing material is irradiated with a laser, the sealing material is heated to 300 ° C. or higher for a moment. When the sealing material exceeds the softening point temperature, the sealing material melts and adheres to the contact surface. Usually, the glass used for PDP is high strain point glass (soda-based glass) and has a large thermal expansion coefficient. For this reason, the residual stress generated by local heating by the laser is relatively large. When the laser irradiation is completed, the temperature is lowered at a stretch, and stress is generated in the sealing material or in the sealing material and the bonding surface. In addition, since the temperature decreases very quickly, the stress remains large without being relaxed. If a panel is formed in this state, it will cause cracks in the material over time.

  (2) The second problem is that the risk of panel cracking during laser heating is high. In the process of sealing the panel, in order to prevent the peeling of the substrate for a long period of time, sufficient adhesion between the sealing material and the adhesive surface is necessary. Therefore, when sealing a panel only by laser heating, it is necessary to increase the power of laser heating sufficiently. However, as the power applied for laser heating increases, the risk of panel cracking increases.

  More specifically, the panel is in a state where the front plate and the back plate are bonded by a sealing material. When the adhesive area of the sealing material is small, the adhesive force is small, and the risk of causing peeling due to external impacts, changes in internal pressure, and external pressure increases. For this reason, even when sealing a panel by laser heating, it is necessary to adhere | attach a front board and a backplate with sufficient area. Therefore, it is necessary to increase the laser power in order to sufficiently melt the sealing material and increase the bonding area. However, since the heating temperature becomes high, the temperature difference generated between the sealing material and the bonding surface increases, and the risk of panel cracking increases.

  In consideration of the above-mentioned problems, the present invention makes it unnecessary to perform the process from the deposition of the protective film to the sealing in a vacuum atmosphere, and the panel cracks due to the residual stress generated in the sealing process over time. Alternatively, an object of the present invention is to provide a method for manufacturing a plasma display panel in which the risk of panel cracking due to high-power laser heating in the sealing process is reduced.

  The method of manufacturing a plasma display panel according to the present invention includes a front plate provided with a plurality of display electrode pairs on a front substrate, a front dielectric layer covering the display electrode pairs, and a protective film covering the front dielectric layer. A plurality of address electrodes that three-dimensionally intersect the display electrode pair on a back substrate, a back dielectric layer that covers the address electrode, a rib that partitions discharge cells at the intersection of the address electrode and the display electrode pair, and And a back plate provided with a phosphor layer positioned between the ribs, and the front plate and the back plate are sealed with an internal space provided by a seal layer formed in an outer peripheral region. A method for manufacturing a panel.

In order to solve the above-mentioned problems, a method for manufacturing a plasma display panel according to the present invention includes a step of sealing the panel composed of the front plate and the back plate as one outer peripheral edge of the back plate or the front plate. Forming a sealing material layer containing glass frit at a position to be sealed by the sealing layer in a region; and the back plate and the front plate so that the sealing material layer contacts the front plate or the back plate. And a pre-sealing step of pre-sealing the panel by locally heating the upper end portion of the sealing material layer to join the front plate or the back plate, and pre-sealing the panel And a sealing step of sealing between the front plate and the back plate by the whole of the sealing material layer, and the sealing material layer is made of glass frit. Forming a two-layer structure comprising a localized heating sealing material layer forming its upper囲気heat sealant layer, and as the local heating sealing material layer, the material easily absorbs the laser beam than the ambient heat sealing material layer A laser heating sealing material layer is formed, and in the preliminary sealing step, the laser heating sealing material layer is irradiated with a laser beam whose irradiation spot diameter is narrower than the width of the laser heating sealing material layer in the cross section in the plane direction of the panel. The upper end of the substrate is locally heated .

According to the manufacturing method of the PDP having the above structure, that the panel by local heating of the upper portion of the sealing material layer abolish preliminary sealing. After pre sealing step of a low energy like this, performing sealing by the entire sealing material layer by atmosphere heating panels.

  Therefore, since the sealing step is performed with the panel sealed by the preliminary sealing step, it is possible to suppress the deterioration of the protective film. Moreover, the sealing material is sufficiently heated in the sealing process, and the temperature is gradually lowered, so that the residual stress can be made very small compared to laser sealing. Can be avoided. Further, since the upper end portion of the sealing material layer is locally heated in the preliminary sealing step, for example, even when laser heating is performed, extremely small heat energy is only applied for a short time. Therefore, the occurrence of a rapid temperature difference is avoided, and the risk of panel cracking during heating is small.

The sealing structure of the front plate and back plate of the PDP in Embodiment 1 of the present invention is shown, (a) is a front view, (b) is a cross-sectional view. Sectional drawing which shows the process of carrying out preliminary sealing of the front board and back board in the embodiment Sectional drawing which shows each process for sealing the front board and back board in the embodiment Graph showing changes in temperature and pressure in the panel in each process The sealing structure of the front plate and back plate of PDP in Embodiment 2 is shown, (a) is a front view, (b) is a sectional view. The sealing structure of the front plate and back plate of PDP in Embodiment 3 is shown, (a) is a front view, (b) is sectional drawing. The front plate | board and the back plate | board sealing process in the embodiment are shown, (a) is sectional drawing, (b) is a front view. The sealing structure of the front board and back board of PDP in Embodiment 4 is shown, (a) is a front view, (b) is sectional drawing. The sealing structure of the front plate and back plate of PDP in Embodiment 5 is shown, (a) is a front view, (b) is sectional drawing. The sealing structure of the front board and back board of PDP in Embodiment 6 is shown, (a) is a front view, (b) is sectional drawing. Sectional drawing which shows each process for sealing the front board and back board in the embodiment Graph showing changes in temperature and pressure in the panel in each process The sealing structure of the front plate and back plate of PDP in Embodiment 7 is shown, (a) is a front view, (b) is a sectional view. The perspective view which showed a part of PDP of the prior art example in the state which isolate | separated the front board and the back board Sectional drawing which shows the state by which the front plate and back plate of FIG. 14 were united.

  The plasma display panel manufacturing method of the present invention can take the following aspects based on the above-described configuration.

  That is, in the first plasma display panel manufacturing method, the local heating in the preliminary sealing step can be performed by a laser beam or a halogen lamp.

  Further, as the local heating sealing material layer, a laser heating sealing material layer is formed of a material that absorbs laser light more easily than the atmosphere heating sealing material layer, and the local heating in the preliminary sealing step is performed using a laser beam. It can be set as the structure to perform.

  Moreover, it is preferable to form the width | variety in the cross section of the said panel surface direction of the said local heating sealing material layer narrower than the width | variety of the said atmosphere heating sealing material layer.

  Moreover, it can be set as the structure which forms a low softening point sealing material layer with the material whose softening point is lower than the said atmosphere heating sealing material layer as the said local heating sealing material layer. In that case, the low softening point sealing material layer can be formed using metal solder.

  Further, the sealing material layer is formed as a single layer of a laser heating sealing material layer made of a glass frit mixed with a material that easily absorbs laser light. In the preliminary sealing step, the irradiation spot diameter of the panel is set. The upper end portion of the laser heating sealing material layer can be locally heated by a laser beam narrower than the width of the laser heating sealing material layer in the cross section in the plane direction.

  In the second plasma display panel manufacturing method, metal solder is used to form the low softening point sealing material layer, and the preliminary sealing step is performed by causing the back plate and the front plate to face each other. A step of positioning so that a predetermined gap is formed between the atmosphere heating sealing material layer and the front plate or the back plate; and the metal solder is inserted into the gap between the atmosphere heating sealing material layer and the front plate or the back plate. The method may include a step of joining the back plate and the front plate with a metal solder seal layer that is supplied in a molten state and formed by cooling and solidifying the metal solder.

  Further, the preliminary sealing step includes a step of forming the low softening point sealing material layer at a position corresponding to the atmosphere heating sealing material layer of the front plate or the back plate, the atmosphere heating sealing material layer, Positioning the back plate and the front plate to face each other so that the low softening point sealing material layer abuts, and locally heating the low softening point sealing material layer to join the back plate and the front plate; It can be set as the structure containing.

  In any one of the above manufacturing methods, the sealing step includes a temperature raising step for heating to the vicinity of the softening point of the sealing material layer, a heat retaining step for holding the vicinity of the softening point, and a temperature higher than the softening point And a temperature lowering step of lowering the temperature after being held at a temperature lower than the softening point for a certain time.

  In this case, after the pre-sealing step and before the sealing step, the panel internal space surrounded by the sealing material layer between the back plate and the front plate is filled with a vacuum atmosphere or an inert gas. Or it can be set as the structure adjusted to the atmosphere filled with desired gas.

  In the heat retaining step and the high temperature heating step, it is preferable to apply a pressure against the deformation of the sealing material layer due to the action of the pressure of the external atmosphere to the inner space of the panel.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Each embodiment relates to a method of manufacturing a PDP having the same structure as the conventional example shown in FIGS. Accordingly, the same components as those of the conventional example shown in FIGS. 14 and 15 are denoted by the same reference numerals, and the description thereof will not be repeated.

<Embodiment 1>
A method of manufacturing the PDP in the first embodiment will be described with reference to FIGS. FIG. 1 shows a sealing structure of a front plate 1 and a back plate 8 of a PDP in the present embodiment, where (a) is a front view and (b) is a cross-sectional view. FIG. 1B shows a state before the front plate 1 and the back plate 8 are sealed. However, since the present embodiment has a feature in the sealing structure of the back plate 8 and the front plate 1, elements unnecessary for explanation of this feature, for example, scan electrode, address electrode, dielectric layer, protection The film and the like are not shown. The same applies to the following embodiments.

  As shown in FIG. 1A, a frame-shaped sealing material layer 20 is formed at a position to be sealed by the sealing layer in the outer peripheral area of the back plate 8. An exhaust pipe 21 is set in advance on the glass substrate of the back plate 8 and connected by a sealing material. The exhaust pipe 21 is used for exhausting or filling a desired gas in the panel internal space surrounded by the sealing material layer 20 between the back plate 8 and the front plate 1.

  The sealing material layer 20 is composed of two layers, an atmosphere heating sealing material layer 20a containing a low melting point glass frit as in the prior art and a laser heating sealing material layer 20b as an upper layer. The laser heating sealing material layer 20b is used as a local heating sealing material layer. The laser heating sealing material layer 20b is obtained by mixing a laser absorbing material in the same glass frit as the atmosphere heating sealing material layer 20a. The height of the upper end of the atmosphere heating sealing material layer 20 a is set higher than that of the rib 12.

  FIG. 2 is a cross-sectional view showing a process for pre-sealing a panel composed of the front plate 1 and the back plate 8, which is a feature of the present embodiment. That is, after the front plate 1 is disposed on the back plate 8 as shown in FIG. 1B, the laser heating sealing material layer 20b is in contact with the front plate 1 as shown in FIG. Position to. In this state, the laser heating sealing material layer 20b is locally heated by the laser beam 22 through the front plate 1 and bonded to the abutting front plate 1 to pre-seal the panel. The local heating means that only the laser heating sealing material layer 20b is heated to such an extent that at least a part thereof is melted and joined to the front plate 1 to form a sealing structure. That is, since the sealing action occurs only at a part of the tip of the sealing material layer 20 and the other parts of the sealing material layer 20 do not change, this is referred to as a preliminary sealing process.

  In the panel preliminarily sealed in this way, the panel internal space surrounded by the sealing material layer 20 between the back plate 8 and the front plate 1 is sealed from the outside air. As described above, the protective film made of a material such as MgO, CaO, or SrO is exposed to the atmosphere by the pre-sealing process by the laser heating sealing material layer 20b using local heating such as laser heating. It is possible to suppress changes.

  When the laser heating sealing material layer 20b is locally heated by the laser beam 22, the laser energy is lowered, the laser irradiation time is shortened, or the laser irradiation spot is reduced. By performing heating locally with small energy, the risk of panel cracking due to pre-sealing can be reduced. Further, since the frit of the laser heating sealing material layer may be small and the bonding area may be small, the risk of panel cracking can be suppressed.

  In FIG. 3, the whole process of sealing the front plate 1 and the back plate 8 is shown in cross section. First, as shown in FIG. 3A, the laser heating sealing material layer 20 b is positioned in a state where it is in contact with the front plate 1. In this state, the atmosphere A in the panel interior is the same as the external atmosphere. In this state, as shown in FIG. 2, the laser heating sealing material layer 20 b is melted by local heating with the laser beam 21, and as shown in FIG. 3B, a panel comprising the front plate 1 and the back plate 8. Is pre-sealed. After this preliminary sealing, the atmosphere B in the panel interior is adjusted to an atmosphere filled with a vacuum, an inert gas, or a desired gas, and the sealing step shown in FIG. That is, by heating the panel in an atmosphere in the furnace, the atmosphere heating sealing material layer 20a is melted and the front plate 1 and the back plate 8 are sealed.

  The sealing step is composed of four steps as shown in FIG. FIG. 4 shows changes in temperature (T) and pressure (P) in the panel in each process for sealing the front plate 1 and the back plate 8 of the PDP. In FIG. 4, a temperature raising step S <b> 1 is performed between times t <b> 0 and t <b> 1, and the panel is heated to near the softening point Ts of the glass frit of the sealing material layer 20. Between time t1 and t2, it is heat insulation process S2, and a panel is hold | maintained in the softening point Ts vicinity. Between times t2 and t3 is a high-temperature heating step S3, in which the panel is heated to a high temperature Th that is higher than the softening point Ts. After the time t3, the temperature lowering step S4 is performed. After the panel is held at a low temperature Tl lower than the softening point Ts for a certain time, the temperature is lowered.

  The pressure (P) in the panel is controlled as follows. First, after the pre-sealing step and before the sealing step (before the temperature raising step S1), the interior space of the panel is filled with a vacuum atmosphere, inert gas filling or desired gas, and the initial pressure Pi is set. Adjust to atmosphere. In the temperature raising step S1, the initial pressure Pi is maintained. In the heat retaining step S2 and the high temperature heating step S3, since the temperature is equal to or higher than the softening point Ts, the pressure (P) is increased to apply the anti-deformation pressure Pr to the panel internal space. The anti-deformation pressure Pr is set to a pressure (for example, 40 kPa) that resists deformation of the sealing material layer due to the action of the pressure of the external atmosphere (not pulled into the panel internal space). In the temperature lowering step S4, exhaust is performed and the pressure is lowered to a predetermined set pressure Po.

  As described above, in the sealing step, the residual stress generated as a result of local heating by the laser is alleviated by heating the panel to a temperature at which the glass frit of the sealing material layer 20 is melted. In other words, heating up to the softening point of the sealing material melts the entire frit, and by gradually cooling, the residual stress can be made very small compared to the case where all the heating at the time of sealing is performed with a laser. Is possible. Therefore, panel cracking due to residual stress can be suppressed during long-term use.

  In the above configuration, the laser heating sealing material layer 20b is formed as a local heating sealing material layer and local heating is performed with a laser beam. However, the present invention is not limited to this, and any other local heating method is used. It may be used. For example, a local heating sealing material layer may be formed of a material that easily absorbs light from a halogen lamp, and local heating may be performed with the halogen lamp. However, the local heating sealing material layer needs to be formed of a material having a gas barrier property.

  As a method for forming the sealing material layer 20, either a coating method using a dispenser or a printing method may be used. For example, it is possible to use a process in which the atmosphere heating sealing material layer 20a is first applied or printed, dried and baked, and then the laser heating sealing material layer 20b is applied or printed, dried and baked. Alternatively, after applying or printing the atmosphere heating sealing material layer 20a, the laser heating sealing material layer 20b may be applied or printed, and simultaneously dried and fired. In addition, after applying or printing the atmosphere heating sealing material layer 20a and drying, it is possible to apply and dry the laser heating sealing material layer 20b, and to fire both seals simultaneously.

  As a method for forming the exhaust pipe 21, the exhaust pipe 21 may be installed before the sealing material layer 20 is formed, or the exhaust pipe 21 may be installed after the sealing material layer 20 is formed. It is also possible to bond the exhaust pipe 21 and the panel substrate in a method of bonding the exhaust pipe 21 through the sealing material layer 20 by atmospheric heating, or in preliminary sealing by laser heating.

  The above description of the sealing process and the like can also be applied to other embodiments described below.

<Embodiment 2>
A method of manufacturing the PDP in the second embodiment will be described with reference to FIG. FIG. 5 shows the sealing structure of the front plate 1 and the back plate 8 of the PDP in the present embodiment, where (a) is a front view and (b) is a cross-sectional view.

  The manufacturing method of the present embodiment is basically the same as that of the first embodiment. The difference is that, in the present embodiment, the laser heating sealing material layer 20b shown in FIG. 1 is formed to be narrow as the upper layer of the atmosphere heating sealing material layer 20a to form the narrow laser heating sealing material layer 23. It is. The width in the cross section in the panel surface direction of the narrow laser heating sealing material layer 23 is set to be sufficiently narrower than the width of the atmosphere heating sealing material layer 20a.

  In the preliminary sealing step, the back plate 8 and the front plate 1 are positioned from the state shown in FIG. 5B so that the narrow laser heating sealing material layer 23 contacts the front plate 1. In this state, the narrow laser heating sealing material layer 23 is locally heated by the laser beam. The control of the atmosphere and the like in the preliminary sealing process and the subsequent sealing process can be performed in the same manner as the process described in the first embodiment.

  According to this embodiment, in order to pre-seal the front plate 1 and the back plate 8, the narrow laser heating sealing material layer 23 having a small width may be heated by a laser beam. Further, since the amount of frit for forming the narrow laser heating sealing material layer 23 may be small, the adhesion area that affects the residual stress can be reduced. As a result, it is possible to reduce the panel cracking risk by reducing the residual stress.

<Embodiment 3>
A method of manufacturing the PDP in the third embodiment will be described with reference to FIGS. FIG. 6 shows the sealing structure of the front plate 1 and the back plate 8 of the PDP in the present embodiment, where (a) is a front view and (b) is a cross-sectional view.

  In the present embodiment, instead of the sealing material layer 20 composed of two layers of the atmosphere heating sealing material layer 20a and the laser heating sealing material layer 20b shown in FIG. It is provided on the face plate 8. As described above, the laser heating sealing material layer 24 is formed of a material in which a material that easily absorbs a laser beam is mixed into a frit of low-melting glass.

  The front plate 1 and the back plate 8 prepared as shown in FIG. 6 are pre-sealed by local heating as shown in FIG. FIG. 7 shows a pre-sealing process, (a) is a cross-sectional view, and (b) is a front view. As shown in FIG. 7A, the back plate 8 and the front plate 1 are opposed to each other, and the laser heating sealing material layer 24 is positioned in contact with the front plate 1. Preliminary sealing is performed by locally heating the upper end portion of the laser heating sealing material layer 24 with the laser beam 25 and bonding it to the abutting front plate 1.

  The irradiation spot diameter of the laser beam 25 is narrower than the width of the upper end of the laser heating sealing material layer 24 in the cross section in the surface direction of the panel, for example, about 1 mm. That is, as shown by the laser heating part 24a in FIG. 7B, the center part of the width of the upper end of the laser heating sealing material layer 24 is heated. Thereby, the applied heat energy can be suppressed sufficiently small, and the bonding area that affects the residual stress can be reduced. As a result, it is possible to reduce the panel cracking risk by reducing the residual stress.

  The control of the atmosphere and the like in the preliminary sealing process and the subsequent sealing process can be performed in the same manner as the process described in the first embodiment. According to this embodiment, the process can be simplified.

<Embodiment 4>
A method of manufacturing the PDP in the fourth embodiment will be described with reference to FIG. FIG. 8 shows the sealing structure of the front plate 1 and the back plate 8 of the PDP in the present embodiment, where (a) is a front view and (b) is a cross-sectional view.

  The manufacturing method of the present embodiment is basically the same as that of the first embodiment. The difference is that in Embodiment 1, the frame-shaped sealing material layer 20 is formed in the outer peripheral edge region of the back plate 8, whereas in the present embodiment, as shown in FIG. It is formed in the outer peripheral area of the front plate 1.

  That is, first, an atmosphere heating sealing material layer 20a made of a low melting point glass frit is formed on the front plate 1, and a laser heating sealing material layer 20b is formed thereon. The pre-sealing step is performed by positioning the laser heating sealing material layer 20b in contact with the back plate 8 and locally heating the laser heating sealing material layer 20b through the back plate 8 with a laser beam.

  The control of the atmosphere and the like in the preliminary sealing process and the subsequent sealing process can be performed in the same manner as the process described in the first embodiment. According to the present embodiment, it is possible to suppress thermal degradation of the phosphor.

<Embodiment 5>
A method of manufacturing the PDP in the fifth embodiment will be described with reference to FIG. FIG. 9 shows the sealing structure of the front plate 1 and the back plate 8 of the PDP in the present embodiment, where (a) is a front view and (b) is a cross-sectional view.

  The manufacturing method of the present embodiment is basically the same as that of the third embodiment. The difference is that in the third embodiment, one layer of the laser heating sealing material layer 24 is formed in the outer peripheral region of the back plate 8, whereas in the present embodiment, as shown in FIG. 9B. It is to be formed in the outer peripheral area of the front plate 1.

  In the preliminary sealing step, as shown in FIG. 9B, the back plate 8 and the front plate 1 are opposed to each other, and the laser heating sealing material layer 24 is positioned in contact with the back plate 8. The lower end portion of the laser heating sealing material layer 24 is locally heated by the laser beam through the back plate 8. The irradiation spot diameter of the laser beam is narrower than the width of the upper end of the laser heating sealing material layer 24 in the cross section in the plane direction of the panel, for example, about 1 mm. Thereby, the applied heat energy can be suppressed sufficiently small, and the bonding area that affects the residual stress can be reduced. As a result, it is possible to reduce the panel cracking risk by reducing the residual stress.

  The control of the atmosphere and the like in the preliminary sealing process and the subsequent sealing process can be performed in the same manner as the process described in the first embodiment. According to the present embodiment, it is possible to suppress thermal degradation of the phosphor.

<Embodiment 6>
A method of manufacturing the PDP in the sixth embodiment will be described with reference to FIGS. FIG. 10 shows the sealing structure of the front plate 1 and the back plate 8 of the PDP in the present embodiment, where (a) is a front view and (b) is a cross-sectional view.

  The manufacturing method of the present embodiment is basically the same as that of the first embodiment. The difference is that, in this embodiment, a low softening point sealing material layer 26 is used as shown in FIG. 10B instead of the laser heating sealing material layer 20b shown in FIG. That is, the atmosphere heating sealing material layer 20a made of glass frit is formed in the outer peripheral region of the back plate 8, and the upper end surface of the atmosphere heating sealing material layer 20a and the front plate 1 are joined by the low softening point sealing material layer 26. And pre-sealing. The low softening point sealing material layer 26 is formed of a material having a gas barrier property having a softening point lower than that of the atmosphere heating sealing material layer 20a, such as metal solder. The preliminary sealing step can be performed by the following method.

  In the first method, a low softening point sealing material layer 26 is formed on the atmosphere heating sealing material layer 20a formed on the back plate 8, and the low softening point sealing material layer 26 is formed as shown in FIG. The front plate 1 and the back plate 8 are joined by being brought into contact with the front plate 1 and melting the low softening point sealing material layer 26 by local heating with a laser, a halogen lamp or the like. This method corresponds to a mode in which the local heating sealing material layer is simply replaced with the low softening point sealing material layer 26 from the laser heating sealing material layer 20b in the method of the first embodiment. By using a sealing material layer having a low softening point, it is possible to reduce the laser power and reduce the panel cracking risk.

  In the second method, metal solder is used to form the low softening point sealing material layer. In the preliminary sealing step, first, the back plate 8 and the front plate 1 are opposed to each other and positioned so that a predetermined gap is formed between the atmosphere heating sealing material layer 20 a and the front plate 1. Next, metal solder is supplied in a molten state to the gap between the atmosphere heating sealing material layer 20a and the front plate 1, and the metal solder sealing layer formed by cooling and solidifying the metal solder causes the back plate and the front plate to move forward. Join the face plates. As the metal solder, for example, Sn-Ag-Cu-based, Sn-Bi-based solder can be used.

  In the third method, a low softening point sealing material layer is formed at a position corresponding to the atmosphere heating sealing material layer 20 a of the front plate 1. Next, the back plate 8 and the front plate 1 are positioned facing each other so that the atmosphere heating sealing material layer 20a and the low softening point sealing material layer are in contact with each other, and the low softening point sealing material layer is locally heated to Join the front plates.

  The control of the atmosphere and the like in the preliminary sealing step and the subsequent sealing step can be performed in substantially the same manner as described in the first embodiment, but there are some differences as described below. This will be described with reference to FIGS. 11 and 12. FIG. 11 is a cross-sectional view showing each step of sealing the front plate 1 and the back plate 8, and FIG. 12 is a diagram showing changes in temperature (T) and pressure (P) in the panel in each step. A case where metal solder is used as the low softening point sealing material layer 26 will be described as an example.

  First, the facing front plate 1 and the atmosphere heating sealing material layer 20a are joined by the metal solder layer 27 by the preliminary sealing step of any one of the above methods, and the state shown in FIG. 11A is obtained. . After this preliminary sealing, the atmosphere A in the panel space is adjusted to a vacuum, an inert gas filling or an atmosphere filled with a desired gas, and then a sealing step shown in FIG. 11B is performed. That is, by heating the panel in an atmosphere in the furnace, the atmosphere heating sealing material layer 20a is melted and the front plate 1 and the back plate 8 are sealed.

  The sealing step is composed of five steps as shown in FIG. In FIG. 11, a temperature raising step S <b> 11 is performed between times t <b> 0 and t <b> 1, and the panel is heated to the vicinity of the softening point Tss of the metal solder layer 27. Between the time t1 and t2, it is the 1st heat retention process S12, and after holding a panel in the softening point Tss vicinity, it heats to softening point Tsf vicinity of the glass frit of the atmosphere heating sealing material layer 20a. Between time t2 and t3, it is the 2nd heat retention process S13, and a panel is hold | maintained in the softening point Tsf vicinity. Between times t3 and t4 is a high temperature heating step S14, and the panel is heated to a high temperature Th that is higher than the softening point Tsf. After the time t4, the temperature lowering step S15 is performed, and after the panel is held at a low temperature Tl lower than the softening point Tss of the metal solder for a certain time, the temperature is lowered.

  The pressure (P) in the panel is controlled as follows. First, after the preliminary sealing step and before the sealing step (before the temperature raising step S11), the interior space of the panel is filled with a vacuum atmosphere, inert gas filling or desired gas, and the initial pressure Pi is set. Adjust to atmosphere. In the temperature raising step S11, the initial pressure Pi is maintained. In the first and second heat retention steps S12 and S13 and the high temperature heating step S14, the temperature is equal to or higher than the softening point Tsf, and thus the pressure (P) is increased to apply the anti-deformation pressure Pr to the panel internal space. The anti-deformation pressure Pr is set to a pressure (for example, 40 kPa) that resists deformation of the sealing material layer due to the action of the pressure of the external atmosphere (not drawn into the panel internal space). In the temperature lowering step S15, exhaust is performed and the pressure is lowered to a predetermined set pressure Po.

  As described above, in the sealing step, the residual stress generated as a result of local heating is relieved by heating the panel to a temperature at which the glass frit of the atmosphere heating sealing material layer 20a is melted.

<Embodiment 7>
A method for manufacturing the PDP in the seventh embodiment will be described with reference to FIG. FIG. 13 shows the sealing structure of the front plate 1 and the back plate 8 of the PDP in this embodiment, where (a) is a front view and (b) is a cross-sectional view.

  The manufacturing method of the present embodiment is basically the same as that of the sixth embodiment. The difference is that in the sixth embodiment, the atmosphere heating sealing material layer 20a is formed in the outer peripheral edge region of the back plate 8, whereas in the present embodiment, as shown in FIG. It is formed in the outer peripheral edge region of the face plate 1.

  In the preliminary sealing step of any of the methods described in the sixth embodiment, the front plate 1 and the back plate 8 opposed to each other are joined by the low softening point sealing material layer 26, and the state shown in FIG. obtain. After this preliminary sealing, the atmosphere in the panel interior is adjusted to an atmosphere filled with vacuum, inert gas, or a desired gas, and a sealing step is performed. That is, by heating the panel in an atmosphere in the furnace, the atmosphere heating sealing material layer 20a is melted and the front plate 1 and the back plate 8 are sealed.

  The control of the atmosphere and the like in the preliminary sealing process and the subsequent sealing process can be performed in the same manner as the process described in the sixth embodiment. According to the present embodiment, it is possible to suppress thermal degradation of the phosphor.

  According to the PDP manufacturing method of the present invention, panel cracking due to residual stress during long-term use can be avoided, and the risk of panel cracking during heating in the sealing process is small. It is useful for the production of PDPs using a ring.

DESCRIPTION OF SYMBOLS 1 Front plate 2 Front substrate 3 Scan electrode 3a, 4a Transparent electrode 3b, 4b Bus electrode 4 Sustain electrode 5 Display electrode pair 6 Front dielectric layer 7 Protective film 8 Back plate 9 Back substrate 10 Address electrode 11 Back dielectric layer 12 Rib 12a Vertical rib 12b Horizontal rib 13r Red phosphor layer 13g Green phosphor layer 13b Blue phosphor layer 14 Discharge space 15 Discharge cell 16 Black stripe 20 Sealing material layer 20a Atmospheric heating sealing material layer 20b, 24 Laser heating sealing material layer 21 Exhaust Tubes 22 and 25 Laser beam 23 Narrow laser heating sealing material layer 24a Laser heating part 26 Low softening point sealing material layer 27 Metal solder layer

Claims (1)

A front plate provided on a front substrate with a plurality of display electrode pairs, a front dielectric layer covering the display electrode pairs, and a protective film covering the front dielectric layer;
A plurality of address electrodes that three-dimensionally intersect the display electrode pair on a back substrate, a back dielectric layer that covers the address electrode, a rib that partitions a discharge cell at the intersection of the address electrode and the display electrode pair, and the rib And a back plate provided with a phosphor layer located between,
A method for manufacturing a plasma display panel in which an inner space is provided and sealed between the front plate and the back plate by a seal layer formed in an outer peripheral region,
As a process for sealing the panel consisting of the front plate and the back plate,
Forming a sealing material layer containing glass frit at a position to be sealed by the sealing layer in one outer peripheral region of the back plate or the front plate;
The back plate and the front plate are positioned to face each other so that the seal material layer contacts the front plate or the back plate, and the upper end portion of the seal material layer is locally heated so that the front plate or the back plate A pre-sealing step for pre-sealing the panel by bonding with
A heating step of sealing the space between the front plate and the back plate by the whole sealing material layer by heating the presealed panel in an atmosphere;
The sealing material layer is formed as a two-layer structure including an atmosphere heating sealing material layer made of glass frit and a local heating sealing material layer as an upper layer thereof, and the atmosphere heating sealing material layer is used as the local heating sealing material layer. A laser heating sealing material layer is formed of a material that absorbs laser light more easily than
In the preliminary sealing step, an upper end portion of the laser heating sealing material layer is locally heated by a laser beam having an irradiation spot diameter narrower than a width of the laser heating sealing material layer in a cross section in the plane direction of the panel. A method for manufacturing a plasma display panel.

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