JP2004247260A - Manufacturing method of image forming apparatus, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of an image forming apparatus and an image forming apparatus capable of preventing disconnection of a sealing material and quickly and stably performing sealing work. <P>SOLUTION: Sealing layers 21a, 21b are formed by disposing the sealing material having conductivity along at least one peripheral portion of a front substrate and a back substrate, and a conductor wire is disposed along at least one outer face of the front substrate and the back substrate. The sealing layers 21a, 21b are heated and melted by feeding a current to the sealing layers 21a, 21b in a state that the front substrate and the back substrate are disposed oppositely, a magnetic field is generated by feeding the current to the conductor wire in the same direction as that of the current fed to the sealing layers 21a, 21b, a Lorentz force is generated by providing a magnetic field and by feeding the current to the sealing layers 21a, 21b, and the sealing layers 21a, 21b melted by the Lorentz force is pressed on at least one substrate inner face of the front substrate and the back substrate. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing an image display device including a pair of substrates that are arranged to face each other and whose peripheral portions are joined to each other, and an image display device.
[0002]
[Prior art]
2. Description of the Related Art In recent years, various image display devices have been developed as next-generation lightweight and thin display devices that replace cathode ray tubes (hereinafter, referred to as CRTs). Such an image display device includes a liquid crystal display (hereinafter, referred to as an LCD) that controls the intensity of light using the orientation of a liquid crystal, and a plasma display panel (hereinafter, referred to as a PDP) that emits a phosphor by ultraviolet rays of plasma discharge. ), A field emission display (hereinafter, referred to as FED) in which a phosphor is emitted by an electron beam of a field emission type electron emission element, and a surface conduction electron emission display (hereinafter, referred to as an FED) in which a phosphor is emitted by an electron beam of a surface conduction type electron emission element. Hereinafter, referred to as SED).
[0003]
For example, FEDs and SEDs generally have a front substrate and a rear substrate that are opposed to each other with a predetermined gap therebetween, and these substrates are connected to each other via a rectangular frame-shaped side wall to form a vacuum. Of the envelope. 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 for exciting the phosphor to emit light.
[0004]
Further, in order to support the atmospheric pressure load applied to the rear substrate and the front substrate, a plurality of support members are disposed between these substrates. The potential on the back substrate side is almost the ground potential, and an anode voltage is applied to the phosphor screen. Then, an image is displayed by irradiating the red, green, and blue phosphors constituting the phosphor screen with an electron beam emitted from the electron-emitting device to cause the phosphors to emit light.
[0005]
In such FEDs and SEDs, the thickness of the display device can be reduced to about several millimeters, and the weight and thickness have been reduced compared to CRTs currently used as displays for televisions and computers. can do.
[0006]
For example, in the FED as described above, various manufacturing methods are being studied to join the front substrate and the rear substrate constituting the envelope via the rectangular frame-shaped side walls. For example, in a vacuum device, the entire vacuum device is evacuated to a high vacuum while baking both substrates with the front substrate and the rear substrate sufficiently separated, and when a predetermined temperature and degree of vacuum are reached, the front surface is evacuated. There is a method of bonding the substrate and the rear substrate via the side wall. In this method, usually, indium that can be sealed at a relatively low temperature is used as a sealing material so as not to lower the adsorption ability of the getter.
[0007]
However, although indium is a low melting point metal, its melting temperature is about 160 ° C., and it has been confirmed that even at this temperature, the adsorption ability of the getter is reduced. Further, it was confirmed by experiments that when the sealed image display device was operated at this temperature, the life characteristics deteriorated.
[0008]
As a method for solving these problems, a low-melting-point sealing material such as indium is filled between the substrates, and the sealing material is heated and melted by Joule heat when the sealing material is energized, thereby bonding the substrates together. A method (hereinafter referred to as energization heating) has been studied (for example, see Patent Document 1). According to this method, since only the low-melting-point sealing material can be heated to a high temperature and the getter formation region can be kept at a low temperature, a decrease in the adsorbing ability of the getter can be prevented. In addition, it is not necessary to spend an enormous amount of time for heating and cooling the substrate, and it is possible to bond the substrate and form an envelope in a short time.
[0009]
[Patent Document 1]
JP-A-2002-319346
[0010]
[Problems to be solved by the invention]
However, in the case of electric heating, the sealing material after melting has a certain degree of unevenness or density due to surface tension. In addition, when sealing, it is necessary to arrange one of the substrates with the sealing surface facing downward, and in this case, the unevenness of the sealing material further melted by gravity increases. Then, in the energization heating, heat generation is increased in a concave portion or a rough portion as compared with a convex portion or a dense portion of the sealing material, and the sealing material may be disconnected in this portion.
[0011]
The present invention has been made in view of the above points, and an object of the present invention is to provide a method of manufacturing an image display device capable of preventing disconnection of a sealing material and performing a sealing operation quickly and stably, and an image display method. It is to provide a device.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, a method for manufacturing an image display device according to an aspect of the present invention includes an envelope having a front substrate and a rear substrate, which are opposed to each other and whose peripheral portions are joined to each other; In a method for manufacturing an image display device having a plurality of pixels provided therein,
Along the inner peripheral edge of at least one of the front substrate and the rear substrate, a sealing material having conductivity is arranged to form a sealing layer, and on at least one outer surface of the front substrate and the rear substrate, A conducting wire is arranged along the sealing layer, and electricity is applied to the sealing layer in a state where the front substrate and the rear substrate are arranged to face each other, the sealing layer is heated and melted, and electricity is applied to the conducting wire to the sealing layer. To generate a magnetic field by energizing in the same direction as the direction of the above, a Lorentz force is generated by energizing the sealing layer and the magnetic field, the molten sealing layer by the Lorentz force of the front substrate and the rear substrate The method is characterized in that the peripheral portions of the front substrate and the rear substrate are joined to each other by pressing against at least one of the inner surfaces of the substrates and the molten sealing layer.
[0013]
Further, a method of manufacturing an image display device according to another aspect of the present invention includes an envelope having a front substrate and a rear substrate, which are opposed to each other and whose peripheral portions are joined, and provided in the envelope. In a method for manufacturing an image display device having a plurality of pixels,
Along the inner peripheral edge of at least one of the front substrate and the rear substrate, a sealing material having conductivity is arranged to form a sealing layer, and on at least one inner surface of the front substrate and the rear substrate, Conducting wires are arranged along the sealing layer to face each other, and electricity is applied to the sealing layer in a state where the front substrate and the rear substrate are arranged to face each other, the sealing layer is heated and melted, and the conducting wires are bonded to the sealing layer. To generate a magnetic field by energizing in the opposite direction to the energization direction, generate a Lorentz force by energizing the sealing layer and the magnetic field, and apply the molten sealing layer by the Lorentz force to the front substrate and the back surface. The method is characterized in that the peripheral portions of the front substrate and the rear substrate are joined to each other by pressing the substrate against at least one of the inner surfaces of the substrates and by the molten sealing layer.
[0014]
Further, the image display device according to the aspect of the present invention has a front substrate and a rear substrate opposed to the front substrate, and has a sealing layer containing a conductive sealing material. An envelope having peripheral portions sealed together, a plurality of pixels provided in the envelope, and provided on at least one outer surface of the front substrate and the back substrate, and extending along the sealing layer. And a conducting wire.
[0015]
According to the method for manufacturing an image display device and the image display device configured as described above, by applying a Lorentz force, it is possible to suppress the occurrence of unevenness and coarse / dense generated when the sealing layer is heated by energization, It is possible to keep the shape of the sealing layer uniform. Thereby, the temperature of the entire sealing material can be uniformly increased, and disconnection of the sealing layer can be prevented. Accordingly, it is possible to provide a method of manufacturing an image display device capable of performing reliable bonding in a short time while maintaining the entire substrate at a low temperature and maintaining a stable getter image while maintaining the getter adsorbing ability. be able to.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a method for manufacturing an image display device and an image display device according to an embodiment of the present invention will be described in detail with reference to the drawings. First, the configuration of an FED as an image display device manufactured by the present manufacturing method will be described.
As shown in FIGS. 1 to 4, the FED includes a front substrate 11 and a rear substrate 12, each of which is formed of a rectangular glass plate, and these substrates are opposed to each other with a gap of 1 to 2 mm. The rear substrate 12 is formed to have a larger size than the front substrate 11. The front substrate 11 and the rear substrate 12 are joined to each other via a rectangular frame-shaped side wall 18 to form a flat rectangular vacuum envelope 10 whose inside is maintained in a vacuum state. .
[0017]
Inside the vacuum envelope 10, a plurality of plate-shaped support members 14 are provided to support an atmospheric pressure load applied to the front substrate 11 and the rear substrate 12. These support members 14 each extend in a direction parallel to one side of the vacuum envelope 10, and are arranged at predetermined intervals along a direction orthogonal to the one side. In addition, the support member 14 is not limited to a plate shape, and may be a column shape.
[0018]
On the inner surface of the front substrate 11, a phosphor screen 16 functioning as an image display surface is formed. The phosphor screen 16 is configured by arranging red, green, and blue phosphor layers R, G, and B, and a black light absorbing layer 20 located between these phosphor layers. The phosphor layers R, G, and B extend in a direction parallel to the one side of the vacuum envelope 10, and are arranged at predetermined intervals along a direction orthogonal to the one side. Note that a metal back layer 17 made of, for example, aluminum and a getter film 13 are formed on the phosphor screen 16.
[0019]
As shown in FIG. 3, on the inner surface of the rear substrate 12, a large number of electron-emitting devices 22 each emitting an electron beam are provided as electron emission sources for exciting the phosphor layer of the phosphor screen 16. These electron-emitting devices 22 are arranged in a plurality of columns and a plurality of rows corresponding to each pixel. More specifically, a conductive cathode layer 24 is formed on the inner surface of the back substrate 12, and a silicon dioxide film 26 having a 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. In each cavity 25 on the inner surface of the back substrate 12, a cone-shaped electron-emitting device 22 made of molybdenum or the like is provided. In addition, a number of wirings 23 that supply a potential to the conductive cathode layer and the gate electrode are provided on a peripheral portion of the back substrate 12.
[0020]
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. On the basis of the electron-emitting device, a gate voltage of +100 V is applied when the brightness is highest. Further, +10 kV is applied to the phosphor screen 16. As a result, an electron beam is emitted from the electron-emitting device 22. The size of the electron beam emitted from the electron-emitting device is modulated by the voltage of the gate electrode 28, and the electron beam excites the phosphor layer of the phosphor screen 16 to emit light, thereby displaying an image.
[0021]
Since a high voltage is applied to the phosphor screen 16 in this manner, a high strain point glass is used for the front glass 11, the rear substrate 12, the side wall 18, and the plate glass for the support member 14. As will be described later, the space between the rear substrate 12 and the side wall 18 is sealed with a low-melting glass 19 such as frit glass. The front substrate 11 and the side wall 18 are sealed by a sealing layer 21 containing indium (In) as a low-melting sealing material having conductivity.
[0022]
The low-melting sealing material having conductivity may be a single metal selected from the group consisting of In, Ga, Pb, Sn and Zn instead of indium, or In, Ga, Pb, Sn and Zn. An alloy containing at least one element selected from the group consisting of: In particular, it is desirable to use an alloy containing at least one element selected from the group consisting of In and Ga, an In metal, and a Ga metal. The low melting point sealing material containing In or Ga is made of SiO ₂ The substrate on which the low-melting-point sealing material is disposed is excellent in wettability with a glass substrate mainly containing ₂ It is particularly suitable when it is formed of a glass mainly containing. The most preferable low melting point sealing material is an In metal or an alloy containing In. Examples of the alloy containing In include an alloy containing In and Ag, an alloy containing In and Sn, an alloy containing In and Zn, an alloy containing In and Au, and the like.
[0023]
Further, the FED includes a plurality of, for example, a pair of electrodes 30 and another pair of electrodes 31, and these electrodes are attached to the envelope 10 in a state of being electrically connected to the sealing layer 21. The electrodes 30 and 31 are used as electrodes when applying electricity to the sealing layer 21.
[0024]
As shown in FIG. 5, each electrode 30 is formed by bending a copper plate having a thickness of, for example, 0.2 mm as a conductive member. That is, the electrode 30 is bent so as to have a substantially U-shaped cross section, and a clip portion 32 that can be attached to the front substrate 11 or the rear substrate 12 by sandwiching the peripheral portion thereof, and a wedge-shaped electrode positioned along the clip portion. The body part 34, the contact part 36 located at the extension end of the body part, and the flat conducting part 38 formed by the clip part and the back part of the body part are integrally provided. The contact portion 36 is formed to have a horizontal extension length L of 2 mm or more. In addition, each electrode 31 is formed similarly to the electrode 30.
[0025]
As shown in FIGS. 1 to 3, each of the electrodes 30 and 31 is attached to the vacuum envelope 10, for example, in a state of being elastically engaged with the back substrate 12. That is, the electrode 30 is attached to the vacuum envelope 10 with the peripheral portion of the back substrate 12 elastically held by the clip portion 32. The contact portions 36 of the respective electrodes 30 are in contact with the sealing layer 21 and are electrically connected. The body portion 34 extends from the contact portion 36 to the outside of the vacuum envelope 10, and the conducting portion 38 faces the side surface of the back substrate 12 and is exposed on the outer surface of the vacuum envelope 10. The pair of electrodes 30 are provided at two corners of the vacuum envelope 10 that are separated from each other in a diagonal direction, and are arranged symmetrically with respect to the sealing layer 21. The other pair of electrodes 31 are provided at the other two corners of the vacuum envelope 10 that are separated in the diagonal direction, and are arranged symmetrically with respect to the sealing layer 21.
[0026]
Next, a method of manufacturing the FED having the above configuration will be described in detail.
First, the phosphor screen 16 is formed on a plate glass to be the front substrate 11. In this method, a glass plate having the same size as the front substrate 11 is prepared, and a phosphor stripe pattern is formed on the glass plate 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. By exposing and developing in this state, a phosphor screen is formed on a glass plate serving as the front substrate 11. Thereafter, a metal back layer 17 is formed on the phosphor screen 16.
[0027]
Subsequently, the electron-emitting devices 22 are formed on the glass plate for the rear substrate 12. In this method, a matrix-shaped conductive cathode layer 24 is formed on a sheet glass, and an insulating film of a silicon dioxide film is formed on the 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, a sputtering method or an electron beam evaporation method. Next, a resist pattern having a shape corresponding to the gate electrode to be formed is formed on the metal film by lithography. Using the resist pattern as a mask, the metal film is etched by a wet etching method or a dry etching method to form a gate electrode 28.
[0028]
Thereafter, the insulating film is etched by wet etching or dry etching using the resist pattern and the gate electrode 28 as a mask to form the cavity 25. Then, after removing the resist pattern, a release 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 rear substrate surface. Thereafter, for example, molybdenum as a material for forming a cathode is vapor-deposited from a direction perpendicular to the surface of the rear substrate by an electron beam vapor deposition method. Thus, the electron-emitting device 22 is formed inside the cavity 25. Next, the release layer is removed together with the metal film formed thereon by a lift-off method.
[0029]
Subsequently, the side wall 18 and the support member 14 are sealed on the inner surface of the rear substrate 12 with the low-melting glass 19 in the atmosphere. Thereafter, as shown in FIGS. 6A and 6B, indium is applied to a predetermined width and thickness over the entire periphery of the sealing surface of the side wall 18 to form a sealing layer 21a. Similarly, indium is applied to the sealing surface facing the side wall of the front substrate 11 in a rectangular frame shape with a predetermined width and thickness to form a sealing layer 21b. The filling of the sealing layers 21a and 21b with respect to the sealing surfaces of the side wall 18 and the front substrate 11 can be performed by applying molten indium to the sealing surface as described above, or by filling solid indium with the sealing surface. It is carried out by a method of placing on a surface.
[0030]
Subsequently, as shown in FIG. 7, a pair of electrodes 30 and a pair of electrodes 31 are mounted on the back substrate 12 to which the side walls 18 are joined. The electrode 30 is used to energize the sealing layer 21a on the rear substrate 12 side, and the electrode 31 is used to energize the sealing layer 21b on the front substrate 11 side. At this time, the electrodes are electrically connected to the sealing layer by bringing the contact portions 36 of the respective electrodes 30 into contact with the sealing layer 21a on the side wall 18. Further, the contact portion 36 of each electrode 31 is separated upward from the sealing layer 21a on the rear substrate side and is not electrically connected. The contact portion 36 of each electrode 31 contacts and is electrically connected to the sealing layer 21b on the front substrate 11 side as described later.
[0031]
The electrodes 30 and 31 require a pair of a positive electrode and a negative electrode on the substrate, and the energization paths of the sealing layers 21a and 21b that are energized in parallel between the pair of electrodes may have the same length. desirable. Therefore, the pair of electrodes 30 is mounted on two diagonally opposite corners of the back substrate 12, and the length of the sealing layer 21a located between the electrodes is set substantially equal on both sides of each electrode. I have. Similarly, the pair of electrodes 31 is attached to the other two corners of the rear substrate 12 which are opposite to each other in the diagonal direction, and the length of the sealing layer 21 b located between the electrodes is substantially equal on both sides of each electrode 31. It is set to be equal.
[0032]
After the electrodes 30 and 31 are mounted, the rear substrate 12 and the front substrate 11 are opposed to each other with a predetermined space therebetween, and are put into a vacuum processing apparatus in this state. Here, for example, a vacuum processing apparatus 100 as shown in FIG. 8 is used. The vacuum processing apparatus 100 includes a load chamber 101, a baking, electron beam cleaning chamber 102, a cooling chamber 103, a getter film deposition chamber 104, an assembly chamber 105, a cooling chamber 106, and an unload chamber 107 arranged side by side. ing. A DC power supply 120 for energization and a computer 122 for controlling the power supply are connected to the assembly chamber 105. Each chamber of the vacuum processing apparatus 100 is configured as a processing chamber capable of performing vacuum processing, and all the chambers are evacuated during the manufacture of the FED. These processing chambers are connected by a gate valve (not shown) or the like.
[0033]
The above-described front substrate 11 and rear substrate 12 arranged at a predetermined interval are first loaded into the load chamber 101. Then, after the atmosphere in the load chamber 101 is changed to a vacuum atmosphere, the wafer is sent to the baking and electron beam cleaning chamber 102.
[0034]
In the baking and electron beam cleaning chamber 102, various members are heated to a temperature of 300 ° C. to release the surface adsorption gas of each substrate. At the same time, an electron beam is irradiated from a not-shown electron beam generator attached to the baking and electron beam cleaning chamber 102 onto the phosphor screen surface of the front substrate 11 and the electron emission element surface of the rear substrate 12. At this time, the entire surface of the phosphor screen surface and the entire surface of the electron-emitting device are cleaned by the electron beam by deflecting and scanning the electron beam by a deflector mounted outside the electron beam generator.
[0035]
The front substrate 11 and the rear substrate 12 that have been subjected to the electron beam cleaning are sent to a cooling chamber 103, cooled to a temperature of about 120 ° C., and then sent to a getter film deposition chamber 104. In the vapor deposition chamber 104, a Ba film is formed as a getter film by vapor deposition outside the phosphor layer. The Ba film can prevent the surface from being contaminated with oxygen, carbon, or the like, and can maintain an active state.
[0036]
Subsequently, the front substrate 11 and the rear substrate 12 are sent to the assembly chamber 105. In the assembly chamber 105, as shown in FIG. 9, the front substrate 11 and the rear substrate 12 are held in the assembly chamber in a state where they are opposed to each other. The front substrate 11 is supported by a fixing jig (not shown) so as not to drop.
[0037]
Thereafter, the front substrate 11 and the rear substrate 12 are moved in a direction approaching each other, and the contact portions 36 of the pair of electrodes 31 are respectively brought into contact with the sealing layer 21b of the front substrate 11 to be electrically connected. At this time, since the contact portion 36 is formed to have a horizontal length of 2 mm or more, the contact portion 36 can stably contact the sealing layers 21a and 21b. By applying indium to the contact portions 36 of the electrodes 30 and 31 in advance, it is possible to more stably supply electricity to the sealing material.
[0038]
Subsequently, as shown in FIG. 9 and FIG. 10, the conducting wires 50 a and 50 b for generating a magnetic field are arranged on the outer surface of the front substrate 11 along the sealing layer 21 b. At this time, the conducting wires 50a and 50b are arranged at the same position along the energization path to the sealing layer 21b. That is, the conductive wire 50a is arranged along one long side and one short side of the sealing layer 21b, and is arranged so as to overlap with the sealing layer along a direction perpendicular to the front substrate surface. In addition, the conductor 50b is arranged along the other long side and the short side of the sealing layer 21b, and is arranged so as to overlap with the sealing layer along a direction perpendicular to the front substrate surface. At the same time, the conductors 50a and 50b are arranged in the direction in which the current flows in the same direction as the energization to the sealing layer 21b. That is, the power supply 51a is connected to the conductor 50a, and the power supply 51b is connected to the conductor 50b. As shown by the arrow, the same direction is applied from one corner of the front substrate 11 to the other corner facing the same. The potentials of the power supplies 51a and 51b are set so that current flows through the power supply 51a and 51b.
[0039]
As shown in FIG. 11, a power supply 120 is electrically connected to each of the pair of electrodes 30 and 31. At this time, the connection terminal 40 connected to the power supply 120 is brought into contact with the conductive portion 38 of the electrode 30, and the connection terminal 41 connected to the power supply 120 is brought into contact with the conductive portion 38 of the electrode 31, so that the power supply and the electrode And the electrodes and the sealing layers 21a and 21b can be reliably conducted. In this state, a direct current is applied in a constant current mode to each of the sealing layer 21a on the side wall 18 side and the sealing layer 21b on the front substrate 11 side. At this time, in the sealing layer 21b on the front substrate 11 side, as shown by an arrow in FIG. 11, the same current passes through each energizing path from one corner of the front substrate 11 to the other opposite corner. It is energized in the direction. Thus, the sealing layers 21a and 21b are heated to melt the indium.
[0040]
Further, almost simultaneously with energization of the sealing layers 21a and 21b, energization of the conductors 50a and 50b from the power sources 51a and 51b. As a result, a predetermined current is applied to the conductive members 50a and 50b in the same direction as the sealing layer 21b positioned opposite to the conductive members 50a and 50b. In FIG. 11, the conductors 50a and 50b are omitted in order to avoid complication of the drawing, but actually, as shown in FIG. 10, the conductors 50a and 50b are arranged on the outer surface of the front substrate 11. I have. Then, as shown in FIG. 12, a magnetic field passing through the sealing layer 21 b is generated by energizing the conductive wires 50 a and 50 b. At the same time, since the direction of energization to the conductors 50a and 50b is the same as the direction of energization to the sealing layer 21a, a Lorentz force is generated that presses the molten sealing layer 21b against the inner surface of the front substrate 11. Therefore, by this Lorentz force, generation of unevenness and unevenness in the sealing layer 21b after melting can be regulated, and indium can be stably melted.
[0041]
With the indium on which the sealing layers 21a and 21b are formed as described above, the front substrate 11 and the rear substrate 12 are pressed and adhered in a direction approaching each other while being melted. As a result, the sealing layers 21 a and 21 b are fused to form the sealing layer 21, and the peripheral portion of the front substrate 11 and the side wall 18 are sealed by the sealing layer. The vacuum envelope 10 formed by the above steps is cooled to room temperature in the cooling chamber 106 and taken out of the unloading chamber 107. Thus, the FED is completed.
After completion of the FED, the electrode 30 may be cut off if necessary.
[0042]
As described above, at the time of bonding the substrates, a force for pressing the indium after melting against the inner surface of the substrate is generated by using the Lorentz force generated by the interaction between the current and the magnetic field, and the unevenness of the indium during energization does not occur. It can be kept in various shapes. The Lorentz force is a force received when a charged particle moves in a magnetic field, and the force f is represented by an outer product of I and B, where I is the magnitude of the current and B is the strength of the magnetic field.
f = I × B
On the other hand, the surface tension of the low melting point sealing material differs depending on the material, but is 400 to 600 mN / m for metals such as In, Pb, Zn, and Sn. Therefore, in order to prevent spheroidization on the glass surface due to the surface tension of the low melting point sealing material, Lorentz force against the surface tension may be applied. For example, when a current of 1 A is passed through a conductor existing in a 3000 Gauss magnetic field, a force of 300 mN / m is generated, and spheroidization due to surface tension can be prevented. When the fusion sealing material is arranged downward, it is sufficient to generate a magnetic field that overcomes gravity in addition to surface tension.
[0043]
At this time, it is not preferable to generate Lorentz force using a permanent magnet such as a samarium-cobalt system. The reason is that the magnet decreases in magnetic force when the temperature rises, it is not possible to obtain the desired magnetic field, and the magnetic field must be applied uniformly to keep the low melting point sealing material after melting in a uniform shape However, it is because it is difficult to apply a uniform magnetic field to the low-melting-point sealing material because the shape of the magnet is restricted. Similarly, the use of a coil instead of a magnet is not preferable because it does not produce a uniform magnetic field.
[0044]
When a uniform magnetic field is applied to the low-melting-point sealing material, as described above, a current may be applied to a conductive wire disposed along a current-carrying path of the sealing material. In this case, since a magnetic field is generated concentrically from the conductor, if the distance to the low melting point sealing material is constant, the magnetic field received by the low melting point sealing material will be the same even at the location with the sealing material.
[0045]
In order to obtain Lorentz force that overcomes gravity and surface tension, it is necessary to supply a current of several tens of A or more to the conductor since the current value applied to one pass of the low melting point sealing material is 20 to 40 A. Therefore, the conducting wire needs to have a certain thickness. The generated magnetic field is not related to the thickness of the conductor, but if it is too thick, the distance from the low-melting-point sealing material increases, and the efficiency decreases. If it is too thin, the heat generation will be too great, giving extra heat to the substrate. Therefore, it is desirable to use copper, aluminum, or an alloy thereof as the material of the conductive wire, and to set the thickness to 1 to 5 mm.
[0046]
According to the manufacturing method of the FED configured as described above, since the front substrate and the back substrate are sealed and bonded in a vacuum atmosphere, the surface adsorbed gas is sufficiently released by using both baking and electron beam cleaning. As a result, a getter film having excellent adsorption ability can be obtained. By sealing and joining the indium by energizing and heating, it is not necessary to heat the entire front substrate and the rear substrate, and it is possible to eliminate problems such as deterioration of the getter film and cracking of the substrate during the sealing process, At the same time, the sealing time can be reduced.
[0047]
In addition, by performing energization sealing using indium, the sealing can be completed in a short time, so that a manufacturing method excellent in mass productivity can be realized.
[0048]
In addition, by applying current to the conductor and pressing the molten indium against the substrate with the generated magnetic field, the occurrence of unevenness of the indium is suppressed and the local heating is prevented from increasing, so the entire indium can be almost completely , And can be stably melt-sealed.
Therefore, it is possible to obtain a manufacturing method which is excellent in mass productivity, can quickly and stably seal, and can inexpensively obtain an FED capable of displaying a good image.
[0049]
The present invention is not limited to the above-described embodiment, and can be variously modified in an implementation stage without departing from the gist of the invention. For example, a conducting wire for generating a magnetic field may be provided on the outer surface of the back substrate, and Lorentz force may be applied to the sealing material on the back substrate side, or a conducting wire may be provided on both the outer surface of the front substrate and the back substrate, and the front substrate may be provided. The configuration may be such that the molten sealing materials on the side substrate and the rear substrate side are respectively pressed toward the inner surface of the substrate.
[0050]
Instead of arranging the conductors on the outer surface of the substrate, as shown in FIG. 13, the conductors 50a and 50b may be pasted or embedded on the outer surface of the substrate in advance along the sealing layer. In this case, the two conducting wires 50a and 50b are respectively arranged along different regions of the sealing layer, and are arranged so as to be opposed to the sealing layer along a direction perpendicular to the surface of the substrate. Then, at the time of sealing, these conducting wires 50a and 50b are energized to generate a magnetic field.
[0051]
Further, the conductive wire is not limited to the outer surface of the substrate, and may be arranged on the inner surface side of the substrate. In this case, as shown in FIG. 14, in the manufacturing process, the conductors 50a and 50b are arranged between the front substrate 11 and the rear substrate 12 along the sealing layer. At the time of energizing heating of the sealing material, the indentations of the indium become larger in the downward substrate on which gravity acts, so that the conducting wires 50a and 50b are arranged so as to be closer to the sealing layer 21b of the front substrate 11 here. . Thereafter, by passing a current through the conductors 50a and 50b in a direction opposite to the direction of current flow to the sealing layer 21b of the front substrate 11, as shown in FIG. The force pressed against the upper side, that is, the substrate side acts, and the thickness of the molten indium becomes uniform.
[0052]
On the other hand, with respect to the upward rear substrate 12, by applying a current to the sealing layer 21a in a direction opposite to the direction of the current supply to the conductive wires 50a and 50b, a downward force can be generated for the molten indium. However, when it is not possible to conduct electricity in the direction opposite to the conducting wires 50a and 50b due to restrictions of the electrodes 30 and 31, etc., the influence of the magnetic field may be reduced by slightly increasing the distance between the conducting wire and the sealing layer. In addition, when the conductor is arranged inside the substrate, a step of moving the conductor at the time of sealing is required, but on the other hand, the distance between the conductor and the sealing material can be reduced, and the sealing material can be reduced with a smaller current. Can be pressed against the substrate.
[0053]
In the above-described embodiment, the configuration is such that the sealing layer is energized while a pair of electrodes are attached to opposing diagonal portions of the substrate, but the plurality of electrodes are energized through the sealing layer positioned between the electrodes. Are disposed so as to be equal in length to each other, or may be disposed at a position symmetrical with respect to the sealing layer, and is provided not only at the corner of the envelope but also at other positions. Is also good.
[0054]
Furthermore, in the above-described embodiment, the sealing layer made of indium is provided on both the rear substrate side and the front substrate side, respectively. It is good also as a structure which seals with a back substrate.
[0055]
Further, the side wall of the envelope may be formed integrally with the rear substrate or the front substrate in advance. It goes without saying that the outer shape of the vacuum envelope and the configuration of the support member are not limited to the above-described embodiment. A matrix type black light absorbing layer and a phosphor layer may be formed, and a columnar support member having a cross-shaped cross section may be positioned and sealed with respect to the black light absorbing layer. As the electron-emitting device, a pn-type cold cathode device, a surface conduction type electron-emitting device, or the like may be used. In the above embodiment, the step of bonding substrates in a vacuum atmosphere has been described. However, the present invention can be applied in other atmosphere environments.
The present invention is not limited to the FED, but can be applied to other image display devices such as an SED and a PDP, or to an image display device in which the inside of the envelope does not have a high vacuum.
[0056]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a method of manufacturing an image display device and an image display device capable of preventing disconnection of a sealing material and performing a sealing operation quickly and stably. .
[Brief description of the drawings]
FIG. 1 is a perspective view showing an entire FED according to an embodiment of the present invention.
FIG. 2 is a perspective view showing the internal configuration of the FED.
FIG. 3 is a sectional view taken along the line AA in FIG. 1;
FIG. 4 is an enlarged plan view showing a part of a phosphor screen of the FED.
FIG. 5 is a perspective view showing electrodes of the FED.
FIG. 6 is a plan view showing a front substrate and a rear substrate used for manufacturing the FED.
FIG. 7 is a perspective view showing a state in which electrodes are attached to a rear substrate of the FED.
FIG. 8 is a view schematically showing a vacuum processing apparatus used for manufacturing the FED.
FIG. 9 is a cross-sectional view showing a state in which a rear substrate and a front substrate on which indium is arranged are arranged to face each other.
FIG. 10 is a plan view showing a state where conductive wires are arranged on the outer surface of the front substrate in the manufacturing process of the FED.
FIG. 11 is a plan view schematically showing a state in which power is connected to electrodes of the FED in the FED manufacturing process.
FIG. 12 is a cross-sectional view schematically showing a state of generation of a magnetic field and Lorentz force when a current is applied to the conductor.
FIG. 13 is a perspective view showing an FED according to another embodiment of the present invention.
FIG. 14 is a cross-sectional view showing a process of manufacturing an FED according to still another embodiment of the present invention.
FIG. 15 is a cross-sectional view schematically showing a state of generation of a magnetic field and Lorentz force when a current is supplied to the conductor.
[Explanation of symbols]
10: vacuum envelope, 11: front substrate, 12: rear substrate,
14 support member 16 phosphor screen 18 side wall
21, 21a, 21b ... sealing layer, 22 ... electron-emitting device,
30, 31 ... electrode, 50a, 50b ... lead wire, 100 ... vacuum processing device

Claims (11)

In a method for manufacturing an image display device including an envelope having a front substrate and a rear substrate that are arranged to face each other and whose peripheral portions are joined to each other, and a plurality of pixels provided in the envelope,
Along the inner peripheral edge of at least one of the front substrate and the rear substrate, a sealing material having conductivity is arranged to form a sealing layer,
On at least one outer surface of the front substrate and the rear substrate, a conductor is arranged along the sealing layer,
Electricity is applied to the sealing layer in a state where the front substrate and the rear substrate are arranged to face each other, and the sealing layer is heated and melted,
The conductor is energized in the same direction as the energization of the sealing layer to generate a magnetic field, and the energization of the sealing layer and the magnetic field generate a Lorentz force. Pressing the deposited layer against the inner surface of at least one of the front substrate and the back substrate,
A method of manufacturing an image display device, wherein peripheral portions of the front substrate and the rear substrate are joined to each other by the molten sealing layer. In a method for manufacturing an image display device including an envelope having a front substrate and a rear substrate that are arranged to face each other and whose peripheral portions are joined to each other, and a plurality of pixels provided in the envelope,
Along the inner peripheral edge of at least one of the front substrate and the rear substrate, a sealing material having conductivity is arranged to form a sealing layer,
On at least one inner surface side of the front substrate and the rear substrate, a conductive wire is disposed to face along the sealing layer,
Electricity is applied to the sealing layer in a state where the front substrate and the rear substrate are arranged to face each other, and the sealing layer is heated and melted,
The conductor is energized in the opposite direction to the energization direction to the sealing layer to generate a magnetic field, and the energization to the sealing layer and the magnetic field generate Lorentz force. Pressing the deposited layer against the inner surface of at least one of the front substrate and the back substrate,
A method of manufacturing an image display device, wherein peripheral portions of the front substrate and the rear substrate are joined to each other by the molten sealing layer. The method of manufacturing an image display device according to claim 1, wherein the conductive wire is disposed so as to be opposed to the sealing layer in a direction perpendicular to the surfaces of the front substrate and the rear substrate. 4. The method according to claim 1, wherein two conductors are respectively arranged along different regions of the sealing layer, and current is separately supplied to each conductor. 5. The method according to claim 1, wherein In or an alloy containing In is used as the sealing material. The method for manufacturing an image display device according to claim 1, wherein an electric current is applied to the sealing layer and the sealing layer in a vacuum atmosphere. An envelope having a front substrate and a rear substrate disposed opposite to the front substrate, and a peripheral portion of the front substrate and the rear substrate sealed with a sealing layer containing a conductive sealing material,
A plurality of pixels provided in the envelope;
A conductive wire provided on at least one outer surface of the front substrate and the rear substrate, and extending along the sealing layer. The image display device according to claim 7, wherein the conductive wire is disposed so as to be opposed to the sealing layer in a direction perpendicular to surfaces of the front substrate and the rear substrate. The image display device according to claim 7, wherein the conductive wire includes two conductive wires, and is arranged along different regions of the sealing layer. The image display device according to any one of claims 7 to 9, wherein the sealing material contains any of In and an alloy containing In. 11. The device according to claim 7, further comprising: a phosphor layer provided on an inner surface of the front substrate; and a plurality of electron-emitting devices provided on the rear substrate, each of which excites the phosphor layer. Item 2. The image display device according to item 1.

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