JP2006114404A - Manufacturing method for image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for an image display device that enables stable sealing to be performed in a short time. <P>SOLUTION: Sealing layers 21a, 21b are formed by providing a conductive sealing material along the inner edge of at least one of a first substrate 11 and a second substrate 12, and then the substrates are arranged to be opposed to each other. At least one of the first and second substrates is pressed in a direction in which the substrates get closer to each other while applying a pressing force to at least one of the first and second substrates, and at least portions of the first and second substrates are brought into contact with each other with the sealing layers located between. Two pairs of electrodes 30a, 30b opposed to each other are brought into contact with the sealing layers, and a first current is fed from the electrodes to the sealing layers while applying a pressing force to thereby heat the sealing material and melt regions of the sealing layers that are in contact with the electrodes. Then, a second current lower than the first current is fed from the electrodes to the sealing layers to melt the entire sealing layers, and respective peripheral portions of the first and second substrates are thereby bonded to each other by the sealing layers. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing an image display device having a substrate and a plurality of pixels arranged to face each other.

  In recent years, various image display devices have been developed as next-generation light-weight 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 LCD) that controls the intensity of light using the orientation of liquid crystal, and a plasma display panel (hereinafter referred to as PDP) that emits phosphors by plasma discharge ultraviolet rays. Field emission display (hereinafter referred to as FED) that emits a phosphor with an electron beam of a field emission electron emitter, and a surface conduction electron emission display that emits a phosphor with an electron beam of a surface conduction electron emitter. (Hereinafter referred to as SED).

  For example, an FED or SED generally has a first substrate and a second substrate that are arranged to face each other with a predetermined gap, and these substrates are bonded to each other at peripheral portions through rectangular frame-shaped side walls. Constitutes a vacuum envelope. A phosphor screen is formed on the inner surface of the first substrate, and a number of electron-emitting devices are provided on the inner surface of the second substrate as electron emission sources that excite the phosphor to emit light.

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

  With such FEDs and SEDs, the thickness of the display device can be reduced to a few millimeters, and it is lighter and thinner than CRTs currently used as television and computer displays. can do.

  For example, in the FED as described above, various manufacturing methods have been studied in order to join the first substrate and the second substrate constituting the envelope via the rectangular frame side wall. For example, when the vacuum apparatus is evacuated to a high vacuum while baking both substrates in a state where the first substrate and the second substrate are sufficiently separated from each other, and a predetermined temperature and degree of vacuum are reached. In addition, there is a method in which the first substrate and the second substrate are joined via a side wall. In this method, a low-melting-point metal that can be sealed at a relatively low temperature is usually used as the sealing material so as not to lower the adsorption ability of the getter.

  However, although it is a low melting point metal, its melting temperature is about 160 ° C., and it has been confirmed that the adsorption ability of the getter is lowered even at this temperature. In addition, it was confirmed by experiments that the life characteristics deteriorate when the image display device sealed at this temperature is operated.

As a method for solving these problems, after filling a low-melting-point sealing material such as indium between the substrates, the sealing material itself is heated and melted by the Joule heat to bond the substrates together. A method (hereinafter referred to as energization heating) has been studied (see, for example, Patent Document 1). According to this method, since only the sealing material can be melted at a high temperature while keeping the getter formation region at about 100 to 140 ° C., it is possible to prevent the adsorption ability of the getter from being lowered. 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 substrates and form an envelope in a short time.
JP 2002-319346 A

  In the energization heating sealing described above, the first substrate and the second substrate are overlapped in advance, and indium is energized with an appropriate pressure applied. Since a relatively large current is used as the energization current, indium melts instantaneously. In this case, there is a possibility that the melted surplus indium may protrude from the side of the substrate onto the wiring of the substrate before flowing out from a desired position, for example, from the corner of the substrate. When indium protrudes from an unnecessary portion, a short circuit of the wiring occurs and the product becomes unbearable.

  Further, in order to prevent rapid melting of indium, when the energization time is increased and indium is slowly melted at a low current, the substrate may be broken due to a temperature difference between the indium and the substrate.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for manufacturing an image display device capable of stably performing sealing in a short time.

An image display device manufacturing method according to an aspect of the present invention includes an envelope having a first substrate and a second substrate that are opposed to each other with a gap therebetween and whose peripheral portions are joined to each other, and the envelope In a manufacturing method of an image display device comprising a plurality of pixels provided in the inside,
A conductive sealing material is disposed along the inner peripheral edge of at least one of the first substrate and the second substrate to form a rectangular frame-shaped sealing layer, and the first substrate and the second substrate. Are disposed opposite to each other, and a pressure is applied to at least one of the first substrate and the second substrate to press the substrates in a direction approaching each other, and the first substrate and At least a part of the second substrate is brought into contact with each other, two sets of electrodes facing each other are brought into contact with the sealing layer, and a first current is passed from the electrodes to the sealing layer with the applied pressure applied. Heating the sealing material, melting the region of the sealing layer in contact with the electrode, melting the region of the sealing layer in contact with the electrode, and then applying a second current lower than the first current. Energizing the sealing layer from the electrode to melt the entire sealing layer, It is characterized in that the peripheral portions of the first substrate and the second substrate are bonded by the sealing layer.

  According to the present invention, after the region near the electrode in the sealing layer is first melted, the entire sealing layer is melted, so that the molten surplus sealing material is moved from a predetermined position near the electrode to the outside. It is possible to provide a method for manufacturing an image display device that can be discharged and can be stably sealed in a short time.

  Hereinafter, a method for manufacturing an image display device according to an embodiment of the present invention will be described in detail with reference to the drawings. First, an SED will be described as an image display device to be manufactured.

  As shown in FIGS. 1 and 2, the SED includes a first substrate 11 and a second substrate 12 each made of a rectangular glass plate, and these substrates are arranged to face each other at a predetermined interval. The second substrate 12 is formed with a size larger than that of the first substrate 11. The first substrate 11 and the second 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 at a high vacuum. .

  A plurality of plate-like support members 14 are provided in the vacuum envelope 10 in order to support an atmospheric pressure load applied to the first substrate 11 and the second substrate 12. These support members 14 extend in a direction parallel to one side of the vacuum envelope 10 and are arranged at a predetermined interval along a direction perpendicular to the one side. The support member is not limited to a plate shape, and a columnar member may be used.

  A phosphor screen 16 that functions as an image display surface is formed on the inner surface of the first substrate 11. The phosphor screen 16 is configured by arranging phosphor layers R, G, and B that emit red, green, and blue, and a matrix-shaped light shielding layer positioned between these phosphor layers. On the phosphor screen 16, for example, a metal back layer 17 made of aluminum and a getter film 27 made of barium are sequentially stacked.

  As shown in FIG. 2, on the inner surface of the second substrate 12, a number of surface-conduction types each emitting an electron beam as an electron emission source for exciting the phosphor layers R, G, B of the phosphor screen 16 are provided. An electron-emitting device 22 is provided. These electron-emitting devices 22 are arranged in a plurality of columns and a plurality of rows, and constitute pixels. Each electron-emitting device 22 includes an electron emitting portion (not shown) and a pair of device electrodes for applying a voltage to the electron emitting portion. As shown in FIG. 1, a large number of wirings 23 for driving the electron-emitting devices 22 are provided in a matrix on the inner surface of the second substrate 12, and the ends thereof are drawn out of the vacuum envelope 15. ing.

  The SED includes a voltage supply unit (not shown) that applies a voltage to the support substrate 24 and the metal back layer 17 of the first substrate 10. The voltage supply unit is connected to the support substrate 24 and the metal back layer 17. When displaying an image in the SED, the video signal is input to the electron-emitting device 22 formed in a simple matrix system. An anode voltage is applied to the phosphor screen 16 and the metal back layer 17, and the electron beam emitted from the electron emitter 22 is accelerated by the anode voltage to collide with the phosphor screen 16. As a result, the phosphor layer of the phosphor screen 16 is excited to emit light and display an image.

  Thus, since a high voltage is applied to the phosphor screen 16, a high strain point glass is used for the plate glass for the first substrate 11, the second substrate 12, the side wall 18, and the support member 14. A space between the second substrate 12 and the side wall 18 is sealed with a low melting point glass 19. The first substrate 11 and the side wall 18 are sealed with a sealing layer 21 containing, for example, indium (In) as a conductive low melting point sealing material.

Next, the manufacturing method of SED comprised as mentioned above is demonstrated.
First, the phosphor screen 16 is formed on the plate glass to be the first substrate 11. In this method, a plate glass having the same size as the first substrate 11 is prepared, and a phosphor 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 first substrate are placed on a positioning jig and set on an exposure table. In this state, the phosphor screen is formed on the glass plate to be the first substrate 11 by exposure and development. Thereafter, a metal back layer 17 is formed on the phosphor screen 16. Subsequently, the electron-emitting device 22 and the wiring 23 are formed on the plate glass for the second substrate 12.

  Next, the side wall 18 and the support member 14 are sealed on the inner surface of the second substrate 12 by the low melting point glass 19 in the atmosphere. Thereafter, as shown in FIGS. 3 and 4, indium is filled to a predetermined width and thickness over the entire circumference of the sealing surface of the side wall 18 to form a rectangular frame-shaped sealing layer 21a. Similarly, indium is filled in a rectangular frame shape with a predetermined width and thickness on the sealing surface facing the side wall of the first substrate 11 to form the sealing layer 21b. The sealing layers 21a and 21b are filled into the sealing surfaces of the side walls 18 and the first substrate 11 by a method of applying molten indium to the sealing surfaces while applying ultrasonic waves.

  Next, as shown in FIGS. 2 and 4, two sets of electrodes 30a and 30b for energization are mounted on the second substrate 12 to which the side walls 18 are bonded. Here, each electrode is formed by bending, for example, a 0.2 mm thick copper plate as a conductive member, and comes into contact with a mounting portion 32 that can be attached by sandwiching the peripheral edge of the second substrate 12 and a contact electrode described later. The tongue piece 35 and the contact portion 36 that can contact the sealing layer 21 are integrally provided. The electrodes 30a and 30b are attached to the second substrate in a state where the peripheral portion of the second substrate 12 is elastically held by the mounting portion 32. At this time, the contact portion 36 of each electrode 30a, 30b is brought into contact with indium formed on the side wall 18, and the electrode is electrically connected to the sealing layer 21a.

  The electrodes 30a and 30b are used as electrodes when energizing the sealing layers 21a and 21b. The electrodes 30a and 30b require a pair of a positive electrode and a negative electrode on the substrate and are energized in parallel between the pair of electrodes. It is desirable that each energization path has the same length. Therefore, one set of electrodes 30a is mounted in the vicinity of a pair of corners facing the diagonal direction of the second substrate 12, and the other set of electrodes 30b is in the vicinity of the remaining pair of corners 2 of the second substrate 12. It is attached to. Thereby, the length of the sealing layer located between the electrodes 30a is set substantially equal on both sides of each electrode. Similarly, the length of the sealing layer located between the electrodes 30b and between the electrodes 30b is set to be approximately equal on both sides of each electrode.

  After mounting the electrodes 30a and 30b, the second substrate 12 and the first substrate 11 are arranged facing each other with a predetermined distance therebetween, and in this state, they are put into a vacuum processing apparatus. Here, for example, a vacuum processing apparatus 100 as shown in FIG. 5 is used. The vacuum processing apparatus 100 includes a load chamber 101, baking, an 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. Connected to the assembly chamber 105 are a DC power supply 120 for energization and a computer 122 that functions as a power supply control unit for controlling the power supply. 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 SED is manufactured. These processing chambers are connected by a gate valve or the like (not shown).

  The first substrate 11 and the second substrate 12 that are arranged with a predetermined interval between them are first put into the load chamber 101. Then, after the atmosphere in the load chamber 101 is changed to a vacuum atmosphere, it is sent to the baking and electron beam cleaning chamber 102. 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 an electron beam generator (not shown) attached to the baking and electron beam cleaning chamber 102 onto the phosphor screen surface of the first substrate 11 and the electron emitter surface of the second substrate 12. At that time, the electron beam is deflected and scanned by a deflection device mounted outside the electron beam generator, whereby the entire surfaces of the phosphor screen surface and the electron-emitting device surface are respectively cleaned with the electron beam.

  The first substrate 11 and the second substrate 12 subjected to the electron beam cleaning are sent to the cooling chamber 103, cooled to a temperature of about 120 ° C., and then sent to the getter film deposition chamber 104. In the vapor deposition chamber 104, a barium film is deposited on the outside of the metal back layer 17 as the getter film 27. The barium film can prevent the surface from being contaminated with oxygen, carbon, or the like, and can maintain an active state.

  Subsequently, the first substrate 11 and the second substrate 12 are sent to the assembly chamber 105. As shown in FIG. 6, hot plates 131 and 132 are disposed inside the assembly chamber 105 so as to face each other with a gap. A stage 134 that can be raised and lowered is disposed below the hot plate 132, and a plurality of support pins 133 are erected vertically on the stage. A movable piece 133 a is attached to the extended end of each support pin 133 via a spring 138. The support pins 133 are slidably inserted into through holes formed in the hot plate 132, and the second substrate 12 can be supported by the tip portions thereof. The support pins 133 and the stage 134 are driven up and down by a motor 135 disposed outside the assembly chamber 105. The stage 134, the support pins 133, and the motor 135 constitute a drive mechanism, and also constitute a support mechanism together with the hot plates 131 and 132. A load cell 139 for measuring the applied pressure acting on the substrate is installed outside the assembly chamber 105 via a bellows 140. The load cell 139 functions as a pressurizing force measuring unit and a measuring instrument.

  At the end of the hot plate 132, two sets of contact electrodes 137 are provided to contact the tongue pieces 35 of the electrodes 30 a and 30 b mounted on the second substrate 12. Each contact electrode 137 is electrically connected to the power source 120 via the energization wiring 136. The current and voltage data output from the power supply 120 to the contact electrode 137 through the energization wiring 136 and the pressure data output from the load cell 139 are input to the computer 121.

  A stage 145 is disposed outside the assembly chamber 105, and an air cylinder 141 is connected to the stage. The hot plate 132 is connected to the stage 145 via a plurality of shafts 142 and bellows 143. By operating the air cylinder 141, the hot plate 132 can be driven up and down in the direction of contacting and separating from the other hot plate 131.

  The first substrate 11 and the second substrate 12 sent to the assembly chamber 105 are first positioned and fixed with respect to the corresponding hot plates 131 and 132, respectively, and the temperature is maintained at about 120 ° C. by these hot plates. At this time, after the first substrate 11 is positioned downward, the first substrate 11 is sucked and fixed to the hot plate 131 by a known electrostatic chucking technique so as not to fall.

  After the mutual alignment of the first substrate 11 and the second substrate 12 is completed, the motor 135 is driven to raise the stage 134 and the support pins 133 so that the second substrate 12 is supported by the support pins 133 and the first substrate 11. The second substrate is pressed with a predetermined pressure against the first substrate. At this time, there is a slight variation in warpage and indium filling amount for each substrate, but the spring 138 provided at the tip of the support pin 133 can absorb these variations. Therefore, any substrate can be stably pressurized. By pressing, the contact portions 36 of the electrodes 30a and 30b are sandwiched between the sealing layers 21b and 21a on the first substrate 11 side and the second substrate 12 side, and each electrode is sandwiched between the sealing layers 21a and 21b of both substrates. At the same time, they make electrical contact. At this time, the applied pressure applied to the second substrate 12 is measured by the load cell 139 and the value is input to the computer 121.

  Thereafter, as shown in FIGS. 7 and 8, the air cylinder 141 is operated to push the hot plate 132 upward, so that the contact electrode 137 contacts the electrodes 30a and 30b from below. In this state, under the control of the computer 121, a direct current of 140A is output as a first current from the power source 120 to the pair of electrodes 30a, and is applied to the sealing layers 21a and 21b through the conductive wiring 136, the contact electrode 137, and the electrode 30a. Energize in constant current mode. After an elapse of a predetermined time, for example, after 5 to 10 seconds, the energization to the electrode 30a is stopped, and instead, a 140 A DC current is output as the first current to the other set of electrodes 30b, and the energization wiring 136, the contact electrode 137, and energizing the sealing layers 21a and 21b through the electrode 30a in the constant current mode for the same time. Thereafter, the electrodes 30a and 30b are energized alternately. Thereby, the indium of the sealing layers 21a and 21b is heated, and the melting of indium starts.

  As shown in FIG. 8, when the sealing layers 21a and 21b are energized from the electrodes 30a and 30b, the corner region a including the region in contact with the electrodes 30a and 30b is first in the sealing layers 21a and 21b. To melt. For example, the corners a of the sealing layers 21a and 21b are melted about 30 seconds after energization is started. As described above, since the pressing force is applied to the second substrate 12, when the indium is melted, the second member 12 is in contact with the inner surface of the first substrate 11 until the supporting member 14 provided on the second substrate completely contacts the second substrate 12. The corners of the substrate 12 are pushed toward the first substrate 11 side. The spring 138 is slightly opened according to the amount of pushing at this time, and the release of the spring pressure is detected by the load cell 139 as a decrease in the applied pressure. This pressure data is input to the computer 121 in real time. During this time, the change in the applied pressure is as shown in FIG. In FIG. 9, point A indicates a point where indium melting of the corner region a of the sealing layer starts and the spring 138 starts to be opened, and point B indicates a point where indium at the corner b is completely melted.

  When the indium in the corner region a is completely melted, the direct current output from the power source 120 to the electrodes 30a and 30b is switched to 70A as the second current that is sufficiently lower than the first current, and the conduction wiring 136 and the contact electrode 137 are switched. The encapsulating layers 21a and 21b are energized in a constant current mode through the electrode 30a. At this time, similarly to the above, the electrodes 30a and 30b are alternately energized every predetermined cycle, for example, every 5 to 10 seconds. Thereby, the indium of the sealing layers 21a and 21b is continuously heated, and the melting of indium in the entire sealing layer starts.

  For example, the side regions b of the sealing layers 21a and 21b are melted about 30 to 90 seconds after the start of application of the second current. When the indium in the side region b is melted, the second substrate 12 is pushed toward the first substrate 11 until the support member 14 provided on the second substrate completely contacts the inner surface of the first substrate 11. The spring 138 is slightly opened according to the amount of pushing at this time, and the release of the spring pressure is detected by the load cell 139 as a decrease in the applied pressure. In FIG. 9, point C is a point where indium melting of the side regions b of the sealing layers 21a and 21b starts and the spring 138 starts to be opened, and point D is a point where the indium of the entire adhesion layer is completely melted and the support member 14 is Each point is shown in full contact with the inner surface of the first substrate 11. After point D, the second substrate 12 is not pushed further into the first substrate 11 side, so the applied pressure does not change. Therefore, the end of the sealing can be determined by detecting the point D in the change in the applied pressure. Then, the energization is stopped at the time when the end of sealing is determined.

  Actually, since it is difficult to detect the point B and the point D in real time, for example, the difference between the applied pressure several seconds before and the current applied pressure is recorded on a computer sequentially, and the applied pressure difference is If it is within a certain value, it is determined that the point B or the point D has been passed, the energization current to the sealing layer is switched, and the energization is terminated. By maintaining the pressurized state for several minutes after the end of energization, indium is cooled and solidified, and the first substrate 11 and the side wall 18 are sealed by the sealing layer 21. Thereby, the vacuum envelope 10 is formed.

  On the other hand, when the sealing layers 21a and 21b are melted during sealing, excess indium is generated. According to this embodiment, first, the corner region a of the sealing layers 21a and 21b is rapidly melted by a high energizing current, and then the side region b of the sealing layer is gradually melted by a small energizing current. Yes. Therefore, the excess indium generated by the melting of the side region b flows toward the corner region a previously melted by being pressurized, and from the predetermined position, here, the first and second substrates 11 and 12 flow out to the outside through the electrodes 30a and 30b. Therefore, the excess indium is restricted from flowing out from the side region b of the sealing layer 21 directly to the outside or inside, and adverse effects on the wiring around the vacuum envelope 10 and the inside of the electron-emitting device are prevented. ing.

  After sealing, the vacuum envelope 10 is sent to the cooling chamber 206, cooled to room temperature, and then taken out from the unload chamber 207. The SED is completed through the above steps. The electrodes 30a and 30b may be removed after sealing.

  According to the manufacturing method of the SED configured as described above, after the melting region of the sealing layer 21 in the vicinity of the electrodes 30a and 30b is first melted, the energization current is lowered to melt the entire sealing layer. Thus, the molten surplus sealing material can flow out from a predetermined position in the vicinity of the electrode, and it is possible to prevent a short circuit of the wiring due to the flowing out indium, damage to the electron-emitting device, and the like. Thereby, SED with high reliability can be manufactured. At the same time, stable sealing can be performed in a short time, and productivity can be improved.

  Further, by determining whether the indium is melted by changing the applied pressure, switching the energization current, and stopping the energization, stable sealing can be performed without being affected by variations in the filling amount of the sealing material. That is, even if variations occur in the width and thickness of the sealing layer for each substrate, changes in the applied pressure can be detected without being affected by the variations. Therefore, the energization heating conditions for the sealing material can be appropriately set for each substrate. This makes it possible to manufacture an SED that can reliably bond in a short time while maintaining the entire substrate at a low temperature, and that can obtain a stable and good image while maintaining the adsorption capability of the getter. it can.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Moreover, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

For example, as the low melting point sealing material having conductivity, instead of indium, a single metal selected from the group consisting of In, Ga, Pb, Sn and Zn, or In, Ga, Pb, Sn and Zn An alloy containing at least one element selected from the group consisting of can be used. In particular, it is desirable to use an alloy containing at least one element selected from the group consisting of In and Ga, In metal, and Ga metal. Since the low melting point sealing material containing In or Ga is excellent in wettability with a glass substrate mainly composed of SiO ₂ , the substrate on which the low melting point sealing material is disposed is glass mainly composed of SiO _2. Particularly suitable when formed. A 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, and an alloy containing In and Au.

  The energization time at the time of sealing and the magnitude of the energization current are not limited to the above-described embodiments, and can be changed as necessary. In the above-described embodiment, the electrodes 30a and 30b are arranged in contact with the corners of the sealing layer 21, but the arrangement positions of the electrodes can be variously changed. For example, as shown in FIG. 10, one set of electrodes 30a is attached to the second substrate 12 in contact with the center of each long side of the sealing layers 21a and 21b, and the other set of electrodes 30b is sealed. You may attach to the 2nd board | substrate 12 in contact with each short side center part of the layers 21a and 21b. In this case, the long-side central region and the short-side central region of the sealing layer 21 that are in contact with the electrodes 30a and 30b are first melted by the first current, and then the other regions of the sealing layer 21 are second current. To melt. And the surplus sealing material produced by the melting of the other region is caused to flow out of the envelope through the electrodes 30a and 30b from the central region of each side of the sealing layer. Even in the case of such a configuration, it is possible to obtain the same effects as those of the above-described embodiment.

In the embodiment described above, the direct current output from the power source to the electrode is switched from the first current to the second current when the indium in the region in contact with the electrode in the sealing layer is completely melted. However, the supply current may be switched from the first current to the second current immediately before the indium in the region in contact with the electrode is completely melted, for example, 0.1 to 5 seconds before.
Even in this case, it is possible to obtain the same effect as that of the above-described embodiment.

  The side wall of the envelope may be formed integrally with the second substrate or the first substrate in advance. Needless to say, the outer shape of the vacuum envelope and the structure of the support member are not limited to the above-described embodiment. A matrix type light shielding 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 light shielding layer. As the electron-emitting device, a pn-type cold cathode device or a surface conduction electron-emitting device may be used. In the above embodiment, the step of bonding the substrates in a vacuum atmosphere has been described. However, the present invention can also be applied in other atmospheric environments. The present invention is not limited to the SED, but can be applied to other image display devices such as an FED and a PDP, or an image display device in which the inside of the envelope does not become a high vacuum.

FIG. 1 is a perspective view showing an entire SED according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the SED along line AA in FIG. FIG. 3 is a plan view showing a first substrate and a second substrate used for manufacturing the SED. FIG. 4 is a perspective view showing a state where electrodes are attached to the second substrate of the SED. FIG. 5 is a diagram schematically showing a vacuum processing apparatus used for manufacturing the SED. FIG. 6 is a cross-sectional view showing an assembly chamber of the vacuum processing apparatus and a state in which a second substrate on which a sealing layer is disposed and a first substrate are disposed to face each other. FIG. 7 is a cross-sectional view showing a state in which the first substrate and the second substrate are pressurized during sealing. FIG. 8 is a plan view schematically showing an arrangement relationship between an electrode mounted on the second substrate and a contact electrode. FIG. 9 is a diagram showing a change in the pressing force of the substrate during sealing. FIG. 10 is a plan view showing the positional relationship between a second substrate and electrodes in another embodiment of the present invention.

Explanation of symbols

10 ... Vacuum envelope, 11 ... first substrate, 12 ... second substrate,
14 ... support member, 16 ... phosphor screen, 18 ... side wall,
21, 21a, 21b ... sealing layer, 22 ... electron-emitting device,
30a, 30b ... electrodes, 100 ... vacuum processing device, 120 ... power supply,
131, 132 ... hot plate, 134 ... stage,
139 ... Load cell

Claims (7)

An image provided with an envelope having a first substrate and a second substrate that are arranged to face each other with a gap and whose peripheral portions are joined to each other, and a plurality of pixels provided in the envelope In the manufacturing method of the display device,
A rectangular frame-shaped sealing layer is formed by disposing a conductive sealing material along the inner peripheral edge of at least one of the first substrate and the second substrate,
After the first substrate and the second substrate are arranged to face each other, a pressure is applied to at least one of the first substrate and the second substrate to press the substrates in a direction approaching each other, and the sealing layer is interposed Sandwiching at least a part of the first substrate and the second substrate between each other,
Contacting two sets of electrodes each facing the sealing layer;
With the applied pressure applied, a first current is applied to the sealing layer from the electrode to heat the sealing material, and the region in contact with the electrode of the sealing layer is melted,
After melting the region of the sealing layer in contact with the electrode, a second current lower than the first current is passed from the electrode to the sealing layer to melt the entire sealing layer, and the first A method for manufacturing an image display device, wherein peripheral portions of a substrate and a second substrate are bonded together by the sealing layer.   The change in the applied pressure is detected during energization of the sealing layer, and the second current is applied when a decrease in the applied pressure is detected after the energization of the first current is started. 2. A method for manufacturing the image display device according to 1.   3. The image display according to claim 2, wherein during the energization of the second current to the sealing layer, the energization to the sealing layer is stopped when the change is lost after the applied pressure decreases. Device manufacturing method.   Contacting the one set of electrodes with a pair of opposite corners of the sealing layer, contacting the other set of electrodes with another set of corners of the sealing layer, and 4. The method for manufacturing an image display device according to claim 1, wherein a current is alternately supplied to the two sets of electrodes.   The pair of electrodes are brought into contact with a pair of long sides of the sealing layer, and the other pair of electrodes are brought into contact with a pair of short sides of the sealing layer, respectively. The method for manufacturing an image display device according to claim 1, wherein a current is supplied to the image display device.   The method for manufacturing an image display device according to claim 1, wherein an excessive portion of the melted sealing material is discharged from a contact position of the electrode to the outside. An image provided with an envelope having a first substrate and a second substrate that are arranged to face each other with a gap and whose peripheral portions are joined to each other, and a plurality of pixels provided in the envelope In the manufacturing method of the display device,
A rectangular frame-shaped sealing layer is formed by disposing a sealing material having conductivity along the inner peripheral edge of at least one of the first substrate and the second substrate,
After the first substrate and the second substrate are arranged to face each other, a pressure is applied to at least one of the first substrate and the second substrate to press the substrates in a direction approaching each other, and the sealing layer is interposed Sandwiching at least a part of the first substrate and the second substrate between each other,
Contacting two sets of electrodes each facing the sealing layer;
With the applied pressure applied, a first current is applied to the sealing layer from the electrode to heat the sealing material, and the region in contact with the electrode of the sealing layer is melted,
Immediately before the region of the sealing layer in contact with the electrode melts, a second current lower than the first current is passed from the electrode to the sealing layer to melt the entire sealing layer, A manufacturing method of an image display device, wherein peripheral portions of one substrate and a second substrate are bonded together by the sealing layer.

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