JP2008269998A - Airtight container and image display device equipped with airtight container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an airtight container which can make a stable sealing and has an improved reliability of strength and provide an image display device equipped with the same. <P>SOLUTION: The airtight container is provided with a first member, a second member arranged to face the first member, and a sealing portion 40 which is arranged between the first member and the second member and seals between the first member and the second member. The sealing portion is composed of a frame body 18 extending along with a circumferential portion of the first and second members, a sealing material 32 filled in a gap between the frame body and the first member and in a gap between the frame body and the second member, and a projected member 42 which is extruded out of a corner portion of the frame body and composes an electrode to be conducted with the frame body. The projected member is made of a metal material of low resistance and is coated by a metal film 44 having corrosion resistance, adhesiveness, and wettability with the sealing material. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an airtight container whose inside is hermetically shielded, and an image display device including the airtight container.

  In recent years, as a lightweight and thin image display device, a liquid crystal display (hereinafter referred to as LCD) that controls the intensity of light using the orientation of liquid crystal, a plasma display panel (hereinafter referred to as LCD) that emits phosphors by ultraviolet rays of plasma discharge. (Referred to as PDP), field emission display (hereinafter referred to as FED) that emits a phosphor with an electron beam of a field emission electron emitter, and surface conduction electron that emits a phosphor with an electron beam of a surface conduction electron emitter. Emission displays (hereinafter referred to as SEDs) have been developed.

  For example, an FED generally has a front substrate and a rear substrate that are arranged to face each other with a predetermined gap, and these substrates are hermetically sealed by bonding their peripheral parts to each other via a rectangular frame-shaped side wall. This constitutes a vacuum envelope shielded by. A phosphor screen is formed on the inner surface of the front substrate, and a number of electron-emitting devices are provided on the inner surface of the rear substrate as electron emission sources that excite the phosphor to emit light.

  In order to support an atmospheric pressure load applied to the back substrate and the front substrate, a plurality of support members are disposed between these substrates. The potential on the back substrate side is substantially the ground potential, and an anode voltage of, for example, 10 kV is applied to the phosphor screen. An image is displayed by irradiating red, green, and blue phosphors constituting the phosphor screen with an electron beam emitted from the electron-emitting device and causing the phosphor to emit light.

  In such an FED, the size of the electron-emitting device is on the order of micrometers, and the distance between the front substrate and the rear substrate can be on the order of millimeters. For this reason, higher resolution, lighter weight, and thinner thickness can be achieved as compared with a cathode ray tube (CRT) used as a display of a current television or computer.

  In such an FED, it is important to maintain a high degree of vacuum inside the vacuum envelope. This is because if the degree of vacuum is low, stable electron emission cannot be performed, and the life of the image display device is reduced.

  As a method for increasing the degree of vacuum inside the vacuum envelope, a method has been proposed in which final assembly of the front substrate, the rear substrate, and the side walls constituting the envelope is performed in a vacuum chamber (for example, Patent Document 1). . The vacuum envelope created by such a method serves both as a sealing process and a vacuum sealing process, and does not require a great amount of time for exhausting the exhaust pipe, and obtains a good degree of vacuum. Can do.

There is also provided an apparatus using a low melting point metal such as indium as a sealing material for sealing the envelope. In order to shorten the sealing time, it is desirable to heat only the sealing material, and a method of locally heating the sealing material and the side wall by energizing them has been proposed (for example, Patent Document 2). reference). In this case, a method of using a protruding portion protruding from the side wall as an electrode at the time of sealing is employed. As an example of the energization method, a method has been proposed in which electrodes are arranged at the four corners of the side wall, and the electrodes corresponding to the diagonals of the substrate are energized alternately to increase the temperature of the side and corner portions of the side wall uniformly. Has been.
JP-A-2005-332618 JP 2001-316922 A

  However, in this case, a current twice as large as that of the side portion of the sidewall flows through the electrode, so that the amount of heat generation is larger than that of the side portion and the temperature is also increased. Therefore, it is necessary to increase the cooling time of the corner portion where the electrode is provided, and there is a concern that thermal distortion stress is generated in the substrate and the substrate is cracked.

  In order to solve such a problem, it can be considered that the electrode is formed of a low-resistance material, for example, Cu or Al, to control the heat generation amount. However, when Sn-based alloy is used as the sealing material, Cu and Al have a high diffusion rate into Sn. Therefore, when the temperature of vacuum heating before sealing is high, Cu and Al are dissolved and disappear. Therefore, it becomes difficult to use as an electrode. Moreover, an intermetallic compound is produced | generated by the corrosion of Cu. Since this compound is hard and brittle, when it is enlarged, the strength characteristics are extremely lowered and the substrate may be broken.

  The present invention has been made in view of the above points, and provides an airtight container capable of performing stable sealing and having improved reliability in strength, and an image display device including the same.

  An airtight container according to an aspect of the present invention includes a first substrate, a second substrate disposed opposite to the first substrate with a gap therebetween, and a sealed portion in which peripheral portions of the first substrate and the second substrate are sealed together. A sealing portion, and the sealing portion includes a frame extending along a peripheral edge of the first and second substrates, a space between the frame and the first substrate, and a frame and the second substrate. And a projecting member that extends outward from a corner portion of the frame body and guides an excess sealing material to the outside from the corner portion of the frame body, and the frame body and Each protruding member has conductivity and is formed of different materials.

An image display device according to another aspect of the present invention includes a first substrate, a second substrate facing the first substrate with a gap therebetween, and a sealing portion in which peripheral portions of the first substrate and the second substrate are joined to each other. And a vacuum envelope having a display surface disposed on the first substrate, and a plurality of electron sources provided on the second substrate to excite the display surface,
The sealing portion includes a frame extending along the peripheral edge of the first and second substrates, a seal filled between the frame and the first substrate, and between the frame and the second substrate. And a projecting member that extends outward from the corner portion of the frame body and guides an excess sealing material to the outside from the corner portion of the frame body, and the frame body and the projecting member each have conductivity. And are made of different materials.

  As described above in detail, according to the present invention, the generation of strain stress can be suppressed at the corner portion of the substrate, the sealing material does not protrude from the sealing portion, and the adhesive strength can be increased. Therefore, it is possible to provide an airtight container with high airtightness and reliability, and an image display device including the same.

Hereinafter, embodiments in which the present invention is applied to an FED as an image display device will be described in detail with reference to the drawings.
As shown in FIGS. 1 and 2, the FED includes a front substrate 11 and a rear substrate 12 each made of rectangular glass, and these substrates are arranged to face each other with a predetermined gap. The front substrate 11 and the back substrate 12 constitute a flat rectangular vacuum envelope 10 whose peripheral portions are bonded to each other via a rectangular frame-shaped side wall 18 and the inside is maintained in a vacuum state. The vacuum envelope 10 constitutes an airtight container. For example, the front substrate 11 constitutes a first member, and the rear substrate 12 constitutes a second member.

  A plurality of plate-like support members 14 are provided inside the vacuum envelope 10 in order to support an atmospheric pressure load applied to the front substrate 11 and the rear substrate 12. These support members 14 extend in a direction parallel to one side of the envelope 10, for example, the long side, and are arranged at a predetermined interval along a direction orthogonal to the one side. . Both ends in the longitudinal direction of each support member 14 are opposed to the side wall 18 with a gap. Each support member 14 is attached to the back substrate 12, for example. The shape of the support member 14 is not particularly limited to this, and a columnar support member may be used.

  As shown in FIGS. 2 and 3, a phosphor screen 16 that functions as a display surface is formed on the inner surface of the front substrate 11. The phosphor screen 16 is configured by arranging red, green, and blue phosphor layers R, G, and B, and a black light shielding layer 20 positioned between these phosphor layers. The phosphor layers R, G, and B of three colors of red, green, and blue are formed alternately with a gap in the first direction, and the phosphor layers of the same color are in the second direction orthogonal to the first direction. Are arranged with a gap in between. Each of the phosphor layers R, G, and B constitutes a subpixel with single colors of red, green, and blue, and constitutes one pixel by combining the subpixels of three colors.

  A metal back layer 17 made of an aluminum film or the like is formed on the phosphor screen 16. According to the present embodiment, the metal back layer 17 has a plurality of divided regions that are divided in the vertical direction and the horizontal direction and are electrically separated from each other. The electrically separated metal back layer 17 is provided so as to overlap the phosphor layers R, G, and B, respectively. A getter film 13 is formed on the metal back layer 17.

  As shown in FIG. 2, a large number of electron-emitting devices that emit electron beams are provided on the inner surface of the back substrate 12 as electron sources that excite the phosphor layers R, G, and B of the phosphor screen 16. ing. That is, a conductive cathode layer 24 is formed on the inner surface of the back substrate 12, and a silicon dioxide film 26 having a large number of cavities 25 is formed on the conductive cathode layer. On the silicon dioxide film 26, a gate electrode 28 made of molybdenum, niobium or the like is formed. A cone-shaped electron-emitting device 22 made of molybdenum or the like is provided in each cavity 25 on the inner surface of the back substrate 12. These electron-emitting devices 22 are arranged in a plurality of columns and a plurality of rows corresponding to the pixels.

  The conductive cathode layer 24 and the gate electrode 28 are formed in stripes in directions orthogonal to each other, and a large number of wirings 23 (on the periphery of the back substrate 12 for supplying potentials to the conductive cathode layer and the gate electrode ( 1) is formed.

  In the FED configured as described above, a video signal is input to the electron-emitting device 22 and the gate electrode 28 formed in a simple matrix system. When the electron-emitting device 22 is used as a reference, a gate voltage of +100 V is applied when the luminance is highest. Further, +10 kV is applied to the phosphor screen 16. The magnitude of the electron beam emitted from the electron-emitting device 22 is modulated by the voltage of the gate electrode 28, and this electron beam excites the phosphor layer of the phosphor screen 16 to emit light, thereby displaying an image. .

  Thus, since a high voltage is applied to the phosphor screen 16, a high strain point glass is used as the plate glass for the front substrate 11, the back substrate 12, and the support member 14. Further, as shown in FIG. 2, the peripheral portions of the front substrate 11 and the rear substrate 12 are joined to each other by a sealing portion 40. That is, the side wall 18 functioning as a frame is disposed between the sealing surface positioned at the inner peripheral edge of the front substrate 11 and the sealing surface positioned at the inner peripheral edge of the rear substrate 12. Further, between the front substrate 11 and the side wall 18 and between the back substrate 12 and the side wall 18, the base layer 31 formed on the sealing surface of each substrate and the Sn formed on the base layer are mainly used. Each of them is sealed by a sealing layer 33 in which a low melting point metal layer 32 as a component is fused. A sealing portion 40 is constituted by the sealing layer 33 and the side wall 18.

  The side wall 18 is made of, for example, a metal such as a Ni alloy. The protruding member 42 protrudes outward from each corner portion of the side wall 18, here, along the diagonal direction of the substrate. The protruding member 42 is formed of a material different from that of the side wall 18, for example, is formed of a low-resistance metal material, Cu, and is joined to the side wall 18. Each protruding member 42 constitutes an electrode for energizing the side wall 18 in the joining process. The protruding members 42 and the front substrate 11 and the protruding members and the rear substrate 12 are bonded to each other by an Sn-based sealing material that flows during sealing.

  For example, the distance between the front substrate 11 and the rear substrate 12 is 2.0 mm, the thickness of the side wall 18 is 1.5 mm, and the thickness of the sealing layer (including the base layer) between the front substrate and the side wall is 0. When the thickness of the sealing layer between the rear substrate and the side wall is 0.25 mm, the gap between the protruding member 42 and the front substrate and the gap between the protruding member and the rear substrate are respectively (the sealing layer It is formed in the range of (layer thickness / 2) to (layer thickness of sealing layer + 0.2) mm. Each of the gaps is filled with an excessive Sn-based metal sealing material.

Next, the manufacturing method of FED which has an airtight container comprised as mentioned above is demonstrated in detail.
First, the phosphor screen 16 is formed on the plate glass to be the front substrate 11. In this method, a plate glass having the same size as the front substrate 11 is prepared, and a phosphor layer stripe pattern is formed on the plate glass by a plotter machine. The plate glass on which the phosphor stripe pattern is formed and the plate glass for the front substrate are placed on a positioning jig and set on an exposure table, whereby the phosphor screen 16 is generated by exposure and development.

  Subsequently, the electron-emitting device 22 is formed on the glass plate for the rear substrate. In this case, a matrix-like conductive cathode layer is formed on the plate glass, and an insulating film of a silicon dioxide film is formed on the conductive cathode layer by, for example, a thermal oxidation method, a CVD method, or a sputtering method.

  Thereafter, a metal film for forming a gate electrode such as molybdenum or niobium is formed on the insulating film by, for example, sputtering or electron beam evaporation. Next, a resist pattern having a shape corresponding to the gate electrode to be formed is formed on the metal film by lithography. Using this resist pattern as a mask, the metal film is etched by wet etching or dry etching to form the gate electrode 28.

  Next, the cavity 25 is formed by etching the insulating film by wet etching or dry etching using the resist pattern and the gate electrode as a mask. Then, after removing the resist pattern, a peeling layer made of, for example, aluminum or nickel is formed on the gate electrode 28 by performing electron beam evaporation from a direction inclined at a predetermined angle with respect to the back substrate surface. Thereafter, for example, molybdenum is deposited as a material for forming the cathode from the direction perpendicular to the surface of the back substrate by an electron beam deposition method. As a result, the electron-emitting device 22 is formed inside each cavity 25. Subsequently, the release layer is removed together with the metal film formed thereon by a lift-off method.

  Then, the side wall 18 arrange | positioned at a peripheral part is formed. For this, four bars each having a rectangular metal cross section or a height defining member are prepared for each side. Both ends of the bar are cut at 45 °, and the end portions are laser welded together to form a rectangular frame-shaped side wall 18. As shown in FIG. 4, metal protruding members 42 are laser welded to the four corner portions of the side wall 18. During welding, it is desirable that no irregularities remain at the joints.

  As shown in FIGS. 2 and 4, the protruding member 42 is formed in a substantially prismatic shape, for example, from Cu. The protruding member 42 is formed to have substantially the same thickness as the side wall 18. At one end of the projecting member 42, a right triangle notch corresponding to the corner of the side wall 18 is formed. Each protruding member 42 is welded to the side wall in a state in which the corner portion of the side wall 18 is fitted into the notch. At this time, the upper and lower surfaces of the protruding member 42 and the upper and lower surfaces of the side wall 18 are joined to each other so as to be flush with each other.

  Next, a silver paste is applied by a screen printing method on the sealing surface positioned at the peripheral edge of the front substrate 11 and the sealing surface positioned at the peripheral edge of the back substrate 12 to form the base layer 31. Subsequently, an Sn-based low-melting-point metal material as a metal sealing material is applied on each base layer 31 to form an Sn-based low-melting-point metal layer 32 extending over the entire circumference of the base layer. At this time, at the corner portion of each substrate, an Sn-based alloy layer is formed about 5 mm outside the base layer 31 so that the Sn-based alloy melted at the time of sealing easily protrudes.

  As the metal sealing material, it is desirable to use a low-melting-point metal material having a melting point of about 350 ° C. or less and excellent adhesion and bonding properties. The Sn-based alloy used in this embodiment has excellent characteristics such as a melting point of about 220 ° C., a low vapor pressure, and no brittleness even at low temperatures. Moreover, since it can be directly bonded to glass depending on conditions, it is a material suitable for the purpose of the present invention.

  Thereafter, the back substrate 12 and the front substrate 11 are sealed to each other through the side wall 18. In this case, as shown in FIG. 5, the back substrate 12 in which the base layer 31 and the low melting point metal layer 32 are formed on the sealing surface, and the front substrate 11 in which the side wall 18 is placed on the low melting point metal layer 32. Is held by a jig or the like in a state where the sealing surfaces face each other and face each other at a predetermined distance, and is put into a vacuum processing apparatus.

  As shown in FIG. 6, this vacuum processing apparatus 100 includes a load chamber 101, baking, electron beam cleaning 102, cooling chamber 103, getter film deposition chamber 104, assembly chamber 105, and cooling chamber 106 arranged side by side. And an unload chamber 107, a drive device 120 for adjusting the temperature and vacuum degree of each chamber, and a control unit 121 for controlling the operation of the entire device. Each chamber of the vacuum processing apparatus 100 is configured as a processing chamber capable of vacuum processing, and all the chambers are evacuated when the FED is manufactured. These processing chambers are connected by a gate valve or the like (not shown).

The rear side assembly and the front substrate 11 that face each other at a predetermined interval are put into the load chamber 101, and after the inside of the load chamber 101 is evacuated, it is sent to baking and electron beam cleaning 102. In the baking and electron beam cleaning 102, when the high vacuum degree of about 10 ⁻⁵ Pa is reached, the back substrate side assembly and the front substrate are baked by heating to a temperature of about 300 ° C. Fully release the gas.

  At this temperature, the Sn-based low melting point metal layer (melting point: about 220 ° C.) 32 melts. However, since the low melting point metal layer 32 is formed on the base layer 31 having high affinity for Sn, Sn is held on the base layer 31 without flowing, and the low melting point metal layer allows the sidewall 18 and the front surface to be retained. The substrate 11 is bonded. Hereinafter, the front substrate 11 bonded to the side wall 18 is referred to as a front side assembly.

  Further, of the molten low melting point metal, the excessive low melting point metal flows out from the corner portion of the side wall 18 and flows into the gap between the protruding member 42 and the front substrate 11 and is filled in this gap. In the subsequent process, it can function as an electrode.

  In the baking and electron beam cleaning 102, simultaneously with heating, an electron beam is irradiated onto the phosphor screen surface of the front substrate 11 and the electron emitting element surface of the rear substrate 12 from an electron beam generator (not shown). Since this electron beam is deflected and scanned by a deflection device mounted outside the electron beam generator, the entire surface of the phosphor screen and the surface of the electron-emitting device can be cleaned with an electron beam.

  After heating and electron beam cleaning, the rear substrate side assembly and the front substrate 11 are sent to the cooling chamber 103 and cooled to a temperature of about 150 ° C., for example. Subsequently, the rear assembly and the front substrate 11 are sent to a getter film deposition chamber 104, where a Ba film is deposited on the outside of the phosphor screen as a getter film. The Ba film is prevented from being contaminated with oxygen, carbon, or the like, and can maintain an active state.

  Next, the front side assembly and the back substrate 12 are sent to the assembly chamber 105 where they are sealed together. Sealing is performed by energizing the Sn-based alloy as a sealing material to melt the Sn-based alloy. For energization, the projecting members 42 provided at the four corners of the substrate are used as electrodes, and the electrodes corresponding to the diagonals of the substrate are alternately energized. Thereby, the temperature of each side part and corner part of the low melting point metal layer 32 is raised uniformly. Sealing can be performed in a short time by the sealing method by energization heating.

  The low melting point metal layer 32 is heated to 250 ° C. by energization heating, and is melted or softened again in a liquid state. In this state, the side wall 18 and the back substrate 12 are joined and pressurized with a predetermined pressure. At this time, part of the pressurized molten sealing material, that is, excess sealing material flows out from the corner portion of the side wall 18, and the gap between the protruding member 42 and the front substrate 11, and the protruding member 42. And flows into the gap between the front substrate 11 and the gap is filled. Thereby, it can suppress that the molten low melting-point metal material protrudes in the direction of a display area | region or a wiring area | region.

Thereafter, the Sn-based alloy is cooled and solidified. Thereby, the space between the back substrate 12 and the side wall 18 and the space between the front substrate 11 and the side wall 18 are sealed by a sealing layer obtained by fusing the Sn-based low melting point metal layer 32 and the base layer 31, respectively. An envelope 10 is formed. Further, the gaps between the protruding members 42 and the front substrate 11 and the gaps between the protruding members and the rear substrate 12 are sealed by the flowing sealing material.
Note that the purpose of this step is to seal the substrate and the side wall, and not limited to energization heating, the entire substrate or the peripheral edge of the substrate may be heated and sealed by a heating source (not shown).
The vacuum envelope 10 formed in this way is cooled to room temperature in the cooling chamber 106 and then taken out from the unload chamber 107. The FED is completed through the above steps.

  According to the FED configured as described above and the manufacturing method thereof, the front substrate 11 and the rear substrate 12 are sealed in a vacuum atmosphere, so that the surface adsorption gas of the substrate can be reduced by the combined use of baking and electron beam cleaning. The gas can be sufficiently released, and the getter film is not oxidized, and a sufficient gas adsorption effect can be obtained. Thereby, FED which can maintain a high degree of vacuum can be obtained.

  In order to reduce the residual strain stress on the substrate at the corner portion of the envelope, it is desirable to make the distance between the protruding member 42 and the substrate close to the thickness of the sealing layer 33. Specifically, if the gap between the protruding member 42 and the substrate is equal to or less than the upper limit value “sealing layer thickness + 0.3 mm”, the substrate cracks the residual strain stress generated due to the shrinkage of the sealing material. It can be suppressed to a range that does not. Further, the lower limit value of the gap is a value at which the surplus sealing material can sufficiently flow to the corner of the substrate, and becomes “sealing layer thickness / 2” or more. Further, it is desirable that the sealing material does not protrude at all from the protruding member 42. However, if the protruding amount is 1 mm or less, the residual strain stress can be suppressed within a range in which the substrate does not crack.

  As described above, the projecting member 42 is provided at the corner portion of the side wall 18, and the surplus sealing material is filled between the projecting member and the substrate so that the thickness is substantially the same as that of the sealing layer. Residual strain stress resulting from the sealing material can be reduced, and damage to the substrate can be prevented. Thereby, the airtight container and FED with improved airtightness and reliability can be provided. Further, by using a metal frame and a protruding member, even a large image display device of 50 inches or more can be easily and reliably sealed, and mass productivity can be improved.

Next, another embodiment of the present invention will be described.
7 to 9 show the protruding member of the FED according to the second embodiment. According to 2nd Embodiment, the protrusion member 42 is comprised by a pair of flat plate 44a, 44b. At one end of each flat plate, a right triangle notch corresponding to the corner of the side wall 18 is formed. Furthermore, one end of each flat plate is bent at a right angle along the notch to form a bent portion 45. The pair of flat plates 44a and 44b are welded to the side walls in a state where the corner portions of the side walls 18 are fitted into the notches. At this time, the flat plates 44a and 44b are joined to the side wall so as to be flush with the upper and lower surfaces of the side wall 18, and face each other with a gap therebetween. The pair of flat plates 44a and 44b protrudes outward from the respective corner portions of the side wall 8, that is, along the diagonal direction of the substrate.

Between the front substrate 11 and the side wall 18 and between the back substrate 12 and the side wall 18, a base layer 31 formed on the sealing surface of each substrate and Sn formed on the base layer as a main component. The low melting point metal layer 32 to be fused is sealed with a sealing layer 33. The gap between the flat plate 44a and the front substrate 11 and the gap between the flat plate 44b and the rear substrate 12 are respectively formed in the range of (sealing layer thickness / 2) to (sealing layer thickness + 0.2) mm. ing. Each of the gaps is filled with an excessive Sn-based metal sealing material.
Also in the second embodiment configured as described above, the same operational effects as those of the first embodiment described above can be obtained.

  FIG. 10 shows an FED according to the third embodiment. According to the third embodiment, the protruding member 42 is constituted by a pair of flat plates 44a and 44b. At one end of each flat plate, a right triangle notch corresponding to the corner of the side wall 18 is formed. The pair of flat plates 44 a and 44 b are notched to match the corner portion of the side wall 18 in the notch, and between the front substrate 11 and the low melting point metal layer 32 and between the back substrate 12 and the low melting point metal layer 32. Each is located and protrudes outward from each corner portion of the side wall 8, that is, along the diagonal direction of the substrate.

  The flat plate 44 a is not directly bonded to the front substrate 11, and a part thereof is in contact with the inner surface of the front substrate. The flat plate 44 b is not directly bonded to the back substrate 12, and a part thereof is in contact with the inner surface of the back substrate. At the time of sealing, the molten excess sealing material flows along the flat plates 44 a and 44 b and is filled between the pair of flat plates 44 a and 44 b on the outer peripheral surface side of the side wall 18. That is, the surplus sealing material is located between the pair of flat plates without entering between the flat plates 44a and 44b and the substrate.

  According to the above configuration, in the structure in which the protruding member is between the sealing layer and the substrate, and the protruding member and the substrate are not bonded to each other, the protruding member is No deformation stress is given to the substrate only by deformation. Thereby, damage to the substrate is prevented, and an airtight container and FED with improved airtightness and reliability are obtained.

  According to 4th Embodiment shown in FIG. 11, a pair of flat plate 44a, 44b which comprises a protrusion member is each bent at an acute angle in the intermediate part, and the cross section is formed in hairpin shape. Thereby, each flat plate 44a and 44b is formed so that elastic deformation is possible centering on a bending part.

  Each of the flat plates 44a and 44b protrudes diagonally and outward from the side wall in a state where the bent portion is located at the corner portion of the side wall 18. One plate portion of each of the flat plates 44a and 44b is disposed in contact with the inner surface of the front substrate 11 or the back substrate 12 through the base layer 31, and the other plate portion is opposed to each other with a gap.

  According to the above configuration, at the time of sealing, the surplus sealing material protrudes between the pair of flat plates 44a and 44b on the outer peripheral surface side of the side wall 18, and further, the flat plates 44a and 44b are deformed even when contracted during cooling. It does not give strain stress to the substrate.

  When the amount of protrusion of the molten sealing material at the time of sealing, for example, Sn-based alloy is large, the protruding member 42 may be shaped as shown in FIG. That is, in the fifth embodiment shown in FIG. 12, the projecting member 42 is configured in the same manner as in the first embodiment described above, and extends beyond the periphery of the front substrate 11 to the outside. When the amount of the melt sealing material is large, the excess sealing material that protrudes flows out from the side wall 18 corner portion along the protruding member 42 on the front substrate 11 side, and the gap between the protruding member and the front substrate Filled. Further, the surplus sealing material flows out beyond the front substrate 11 to the outside and accumulates thickly on the protruding member 42. However, even in this case, even when the sealing material contracts during cooling, no strain stress is applied to the substrate.

According to the sixth embodiment shown in FIG. 13, the projecting end surface 42 a of the projecting member 42 extends obliquely toward the front substrate 11 with respect to the direction perpendicular to the inner surface of the rear substrate 12. In this case, surplus sealing material that protrudes at the time of sealing flows out on the front substrate side 11 beyond the front substrate to the outside, and further flows to the rear substrate 12 side along the extended end surface of the protruding member 42. ing.
Even in the above configuration, the shrinkage of the Sn-based metal existing between the protruding member 42 and the substrate can reduce the influence on the front substrate and the rear substrate.

  The present invention is not limited to the above-described embodiment, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. Some constituent elements may be deleted from all the constituent elements shown in the embodiments, or constituent elements over different embodiments may be appropriately combined.

  For example, the material of the protruding member is not limited to a metal, and a glass material or a ceramic material may be used. There were two sealing parts of the vacuum envelope, but the front substrate and the side wall or the back substrate and the side wall were previously bonded with frit glass etc., and only the remaining joint part was made of the low melting point metal described above. It is good also as a structure to seal.

In the above-described embodiment, the sealing portion is sealed in a vacuum atmosphere. However, the present invention is not limited to this, and may be performed in a stable gas atmosphere. For the sealing of the front substrate and the rear substrate, a batch-type atmospheric firing furnace may be used in addition to the in-line type vacuum processing apparatus.
In the above-described embodiment, the field emission type electron emission element is used as the electron emission element. However, the present invention is not limited to this, and other electron emission elements such as a pn type cold cathode element or a surface conduction type electron emission element are used. It may be used. The present invention can also be applied to other display devices such as FEDSED, PDP, and fluorescent display tube, or to airtight containers of other electronic devices.

FIG. 1 is a perspective view showing a FED according to a first embodiment of the present invention with a part thereof broken. FIG. 2 is a cross-sectional view of the FED along line AA in FIG. FIG. 3 is a plan view showing the phosphor screen of the FED. FIG. 4 is a perspective view showing a side substrate constituting the vacuum envelope of the FED and a front substrate in which a base layer and a low melting point metal layer are formed on a sealing surface. FIG. 5 is a cross-sectional view showing a state in which a front-side assembly in which a base layer and a low-melting-point metal are formed on the sealing portion and a rear substrate are arranged to face each other. FIG. 6 is a diagram schematically showing a vacuum processing apparatus used for manufacturing the FED. FIG. 7 is a cross-sectional view corresponding to FIG. 2 showing a corner portion of an FED according to the second embodiment of the present invention. FIG. 8 is a perspective view showing a side wall corner portion and a protruding member of the FED according to the second embodiment. FIG. 9 is an exploded perspective view showing a side wall corner portion and a protruding member of the FED according to the second embodiment. FIG. 10 is a cross-sectional view corresponding to FIG. 2 showing a corner portion of an FED according to a third embodiment of the present invention. FIG. 11 is a cross-sectional view corresponding to FIG. 2 showing a corner portion of an FED according to a fourth embodiment of the present invention. FIG. 12 is a cross-sectional view corresponding to FIG. 2 showing a corner portion of an FED according to a fifth embodiment of the present invention. FIG. 13 is a cross-sectional view corresponding to FIG. 2 showing a corner portion of an FED according to a sixth embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Vacuum envelope, 11 ... Front substrate, 12 ... Back substrate, 14 ... Support member,
16 ... phosphor screen, 18 ... side wall, 22 ... electron-emitting device, 31 ... underlayer,
32 ... Low melting point metal layer, 40 ... Sealing part, 42 ... Projection member, 44a, 44b ... Flat plate,
100 ... Vacuum processing apparatus

Claims (8)

A first substrate; a second substrate disposed opposite to the first substrate with a gap; and a sealing portion that seals the peripheral portions of the first substrate and the second substrate;
The sealing portion includes a frame extending along the peripheral edge of the first and second substrates, a seal filled between the frame and the first substrate, and between the frame and the second substrate. And a projecting member that extends outward from the corner portion of the frame body and guides an excess sealing material to the outside from the corner portion of the frame body, and the frame body and the projecting member each have conductivity. An airtight container having different materials.   The protruding member is formed in a rod shape having a thickness substantially equal to the frame body, and the gap between the protruding member and the first substrate and the gap between the protruding member and the second substrate are made of a sealing material. 2. The airtight container according to claim 1, wherein the airtight container is formed in a range of ½ of the layer thickness to the layer thickness of the sealing material + 0.2 mm, and an excess sealing material is filled in each gap. The projecting member has a pair of flat plates, one flat plate is opposed to the first substrate with a predetermined gap, and the other flat plate is opposed to the second substrate with a predetermined gap. Are placed opposite each other with a gap between them,
The gap between the flat plate and the first substrate and the gap between the flat plate and the second substrate are formed in a range of 1/2 of the layer thickness of the sealing material to the layer thickness of the sealing material +0.2 mm, The airtight container according to claim 1, wherein an excess sealing material is filled in each gap.   The protruding member has a pair of flat plates, one flat plate is provided in part in contact with the first substrate, and the other flat plate is provided in part in contact with the second substrate. The airtight container according to claim 1, wherein the flat plates are arranged to face each other with a gap therebetween, and an excess sealing material is filled between the pair of flat plates on the outer peripheral side of the frame body. Each of the protruding members has a pair of flat plates bent in two at a substantially central portion, and each flat plate extends outward from the bent portion with the bent portion positioned at the corner portion of the frame body. One plate portion of each flat plate is opposed to the first substrate or the second substrate with a predetermined gap, and the other plate portion is opposed to each other with a gap,
The airtight container according to claim 1, wherein an excess sealing material is filled in a gap between the flat plate and the first substrate, a gap between the flat plate and the second substrate, and the pair of flat plates.   The protruding member protrudes outward beyond the edge of the first substrate, and the excess sealing material flows out from a corner portion of the frame body along the protruding member, and the protruding member and the The hermetic container according to claim 2, wherein the airtight container is filled in a gap with the first substrate, and is accumulated on the protruding member outside the first substrate beyond the gap.   The protruding member has a protruding end surface that protrudes outward beyond an edge of the first substrate and is inclined toward the first substrate with respect to a direction perpendicular to the inner surface of the second substrate, and the excess sealing. The airtight container according to claim 2, wherein the material flows out to the outside beyond the first substrate on the first substrate side, and flows to the back substrate side along the extended end surface of the protruding member. A vacuum envelope having a first substrate, a second substrate opposed to the first substrate with a gap, and a sealing portion joining the peripheral portions of the first substrate and the second substrate;
A display surface disposed on the first substrate;
A plurality of electron sources provided on the second substrate and exciting the display surface,
The sealing portion includes a frame extending along a peripheral edge of the first and second substrates, a seal filled between the frame and the first substrate, and between the frame and the second substrate. And a projecting member that extends outward from the corner portion of the frame body and guides an excess sealing material to the outside from the corner portion of the frame body, and the frame body and the projecting member each have conductivity. An image display device having different materials.

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