JP2010027434A - Fluorescent display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To air-tightly seal an enclosure composing a fluorescent display without limiting material to be used for sealing, and without causing increase of manufacturing processes. <P>SOLUTION: An exhaust hole 109 is provided in one part of a base board 101, the exhaust hole 109 is sealed by an exhaust hole plug 121, and vacuum of an enclosure interior is maintained. The fluorescent display is equipped with a ring like bored part 122 between the base board 101 in a portion of the exhaust hole 109 and the exhaust hole plug 121, the bored part 122 is adhered to the base board 101 by a glass adhesive layer 123, and the exhaust hole plug 121 and the bored part 122 are adhered by a glass adhesive layer (an exhaust hole plug side adhesive layer) 124. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fluorescent display device in which a vacuum vessel is not provided with an exhaust pipe, an exhaust hole is provided in a part thereof, and the inside of the vessel is sealed in a so-called vacuum state.

  The fluorescent display device is a display device that performs desired display by causing electrons emitted from an electron source to collide with a phosphor to emit light in a vacuum container that is transparent at least one of them. For example, there is a fluorescent display tube that performs display by using a thermoelectron emitted from a cathode called a filament as an electron source and emitting a display pattern of a desired shape made of a phosphor. In such a fluorescent display tube, a triode structure having a grid for controlling the function of electrons is most often used.

  In the fluorescent display device configured in this way, after the above-described components are arranged and assembled inside the envelope, the inside is evacuated from the exhaust port provided in the envelope (vacuum container). After a predetermined degree of vacuum (pressure), a lid (exhaust hole plug) is sealed at the exhaust port and the envelope is sealed to form a vacuum container (Patent Documents 1, 2, 3, 4).

  In these techniques, as shown in FIG. 7, the inside of the envelope is evacuated to the exhaust hole provided in the envelope via the exhaust head of the vacuum pump device. First, an exhaust head 710 is connected to a portion of an exhaust hole 702 provided in the envelope 701 to exhaust the interior 703 of the envelope 701 to a desired pressure. The exhaust head 710 is in close contact with the envelope 701 through an O-ring 711. After exhausting the interior 703 in this manner, the exhaust hole plug 704 is pressed against the exhaust hole 702 by the push-up rod 712 provided inside the exhaust head 710, and the exhaust hole 702 is closed with the exhaust hole plug 704. I have to.

  An adhesive material 706 such as low-melting glass is provided on the exhaust hole plug 704. The adhesive 706 is heated and melted via the exhaust hole plug 704 by the heating mechanism built in the push-up bar 712, and in this state, the exhaust hole plug 704 is pressed against the envelope 701 around the exhaust hole 702. Then, the adhesive 706 is fused to the envelope 701, and the exhaust hole plug 704 is adhesively fixed (sealed) around the exhaust hole 702.

  In the above-described method, compared with a manufacturing method in which the entire envelope is placed in a large vacuum exhaust chamber and the exhaust hole is sealed, only the exhaust hole portion is connected to the exhaust head and the inside of the envelope 701 is exhausted. Therefore, it has the feature of excellent mass productivity. However, the portion of the O-ring 711 for connecting the exhaust head 710 is cooled, and the entire envelope 701 outside the O-ring 711 and the portion of the exhaust hole 702 closed by the exhaust hole plug 704 inside the O-ring 711 are heated. Therefore, these sealing regions are in a thermal environment in which cooling and heating are mixed. For this reason, in the sealing by the above-described method, the exhaust hole plug is sealed in a state where it is easy to have distortion. As a sealing material for reducing this thermal strain, a material that can be sealed at a relatively low temperature is required.

  Further, the thermal expansion coefficient of each material (glass substrate, sealing material, exhaust hole plug) used for the sealing portion does not completely match at each temperature (for example, the temperature at which the adhesive solidifies). For this reason, depending on the thermal expansion coefficient of the sealing material of the exhaust hole plug and the temperature at which it is solidified (assumed by the glass transition point, the softening point, the yield point, etc.), stress may be accumulated in the sealing part. Prone. As described above, in a state where stress is accumulated, there is a case where leakage occurs due to generation of a crack in the sealing portion (adhesive surface). Therefore, in sealing in a fluorescent display device, it is important to lower the melting point of the adhesive used for sealing the exhaust hole and to control the thermal expansion coefficient of the material used.

Japanese Utility Model Publication No. 60-012256 JP-A 63-284742 Japanese Patent Laid-Open No. 01-200544 Japanese Patent Laid-Open No. 04-061727 Japanese Patent Laid-Open No. 52-130274 JP-A-53-131751 Japanese Utility Model Publication No. 58-10291

  However, while lead-free processing is being promoted due to compliance with the RoHS directive, it is not easy to lower the melting point and control the thermal expansion coefficient of the frit glass used for the adhesive. Glass that does not use lead generally tends to have a high melting point, and the low melting point glass that can be applied to the bonding of exhaust hole plugs as described above is limited. In many cases, it is difficult to obtain good characteristics, quality It is difficult to ensure reliability. Inevitably, more expensive materials are used.

  By the way, in consideration of compliance with the RoHS directive, it is conceivable to use a so-called lead-free solder for the adhesive (sealing agent). When using lead-free solder, various materials can be selected, and lowering of the melting point of the adhesive can be realized more easily than the glass material. However, when using a solder material, it is necessary to form a thin metal layer in advance around the exhaust hole by plating or sputtering, and only in the local area where the exhaust hole is located in the large substrate. Pattern formation of a thin film has a problem in mass productivity in terms of space efficiency, handling, and film formation cost (see Patent Documents 5, 6, and 7).

  As described above, in order to realize lead-free, conventionally, a fluorescent display device is configured by using a cheaper material without increasing the number of manufacturing processes and without limiting the material of the adhesive. There is a problem that the inside of the envelope cannot be sealed, resulting in an increase in manufacturing cost, quality and reliability.

  The present invention has been made in order to solve the above-described problems, and expands the choices of materials used for sealing, reduces the environmental burden, increases mass productivity, and provides quality and reliability. An object of the present invention is to make it possible to hermetically seal the envelope constituting the fluorescent display device in a state in which is held.

  A fluorescent display device according to the present invention includes an envelope made of glass containing therein an anode formed with a phosphor layer and an electron emission source, an exhaust hole formed in the envelope, and an envelope of the envelope A perforated part bonded to the exhaust hole with a substrate-side adhesive layer made of lead-free glass, and an exhaust connected to the perforated part with an exhaust hole plug-side adhesive layer made of a lead-free material and continuous to the hole of the perforated part At least an exhaust hole plug for sealing the hole is provided.

  In the fluorescent display device, the perforated component may be made of metal. The perforated part may be made of a material selected from glass and ceramic. Moreover, the exhaust hole stopper side adhesive layer should just be comprised from the lead-free glass. The exhaust hole plug side adhesive layer may be made of a metal not containing lead that melts at a temperature of 400 ° C. or lower.

  As described above, according to the present invention, the exhaust hole is sealed by adhering the exhaust hole plug to the perforated part bonded with the adhesive layer made of lead-free glass. The choice of materials to be used is wide, lead-free materials with low environmental impact can be used, and the envelope that constitutes the fluorescent display device is hermetically sealed while maintaining quality and reliability without sacrificing mass productivity. An excellent effect is obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the material for bonding the perforated part and the exhaust hole plug described below is a lead-free material, and does not contain lead and is made of a material other than lead.

[Embodiment 1]
First, Embodiment 1 of the present invention will be described with reference to FIGS. 1A, 1B, 1C, and 1D. 1A, 1B, 1C, and 1D are cross-sectional views showing the configuration of the fluorescent display device according to Embodiment 1 of the present invention. FIG. 1B shows an enlarged part of FIG. 1A.

  In this fluorescent display device, a wiring layer 102 is formed on a substrate 101 having insulating properties such as glass, and an insulating layer 103 is formed on the wiring layer 102. An anode electrode 104 is formed at a predetermined position on the insulating layer 103, and the anode electrode 104 is connected to the wiring layer 102 through a through hole 103 a opened in the insulating layer 103. A phosphor layer 105 is formed on the anode electrode 104, a grid 106 is disposed on the phosphor layer 105, and a filament 107 is disposed above the grid 106.

  On the other hand, an upper container 108 is disposed at the end of the substrate 101, and the substrate 101 and the upper container 108 constitute an envelope made of glass. The substrate 101 and the upper container 108 are sealed with a sealing layer 110 made of low melting point glass. In addition, an electrode 111 connected to the wiring layer 102 is formed in a part (peripheral portion) inside the envelope of the substrate 101, and a lead 112 for connection to the outside is connected to the electrode 111. The lead 112 is taken out through the sealing layer 110 at the contact portion between the upper container 108 and the substrate 101.

  In addition, an exhaust hole 109 is provided in a part of the substrate 101, and the exhaust hole 109 is sealed with an exhaust hole plug 121 to maintain a vacuum inside the envelope. In the fluorescent display device according to the present embodiment, a ring-shaped perforated part 122 is provided between the substrate 101 and the exhaust hole plug 121 in the exhaust hole 109, and the perforated part 122 is a glass adhesive layer (substrate-side adhesive layer). ) 123 is bonded to the substrate 101, and the exhaust hole plug 121 and the perforated component 122 are bonded by a glass adhesive layer (exhaust hole plug side adhesive layer) 124. The exhaust hole plug 121 is bonded to the perforated part 122 with a glass adhesive layer 124 and seals the exhaust hole 109 continuous to the hole part of the perforated part 122.

  The perforated part 122 is a disk having a thickness of 0.1 mm, which is made of, for example, a well-known 426 alloy and has a circular opening with a diameter of 2 mm at the center. The perforated component 122 configured as described above can be easily mass-produced by processing a larger 426 alloy plate by, for example, a well-known etching process or press die cutting.

The perforated part 122 is a metal material and has an appropriate plasticity (ductility), so that it can absorb a certain amount of stress generated when the exhaust hole plug is bonded. For example, the material of the perforated part is not limited to the 426 alloy, but any other material having appropriate plasticity and a thermal expansion coefficient suitable for this purpose, such as 50Ni-Fe alloy, 52Ni-Fe alloy, And SUS430 or the like. The material of the perforated component 122 may be selected according to the material characteristics of the adhesive layer to be used. Here, when a stress is generated by sealing the exhaust hole plug 121, a material that generates a stress in a direction opposite to the generated stress may be selected. In this case, the perforated component 122 may be made of a material having a thermal expansion coefficient in the range of 40 to 110 × 10 ⁻⁷ / ° C.

  In addition, an oxide film (not shown) is formed on the surface of the perforated component 122 on the glass adhesive layer 123 side in order to improve adhesion to the low melting point glass. Similarly, an oxide film (not shown) is formed on the surface of the perforated component 122 on the glass adhesive layer 124 side in order to improve the adhesion with the glass adhesive layer 124.

The glass adhesive layer 123 is a lead-free low-melting glass having a softening point of about 350 to 450 ° C. and a thermal expansion coefficient of about 70 to 90 × 10 ⁻⁷ / ° C. The glass adhesive layer 123 may be a glass material that does not generate stress such as a crack with the substrate 101 when it is melted to bond the perforated component 122 and after the bonding. The same lead-free low melting point glass as the sealing layer 110 that seals the container 108 and the substrate 101 may be used. These lead-free low melting glass is a glass material made of a material that does not contain lead. For example, there is a glass material in which lead, which is a main material for lowering the melting point, is replaced with bismuth, tin, phosphorus, or the like. In addition, lead may be mixed unintentionally in the manufacturing process of glass or the like, but “not containing lead” and “lead-free” are included, including cases in which a very small amount of lead is included.

  The glass adhesive layer 124 is preferably made of a material having a softening point lower than that of the glass adhesive layer 123 (lead-free glass), and is composed of a lead-free low-melting glass material having a softening point in the range of 250 to 400 ° C. Good. Practically, for example, an exhaust hole plug-side adhesive layer (glass adhesive layer 124) made of the frit (frit glass) of the low melting point glass material may be formed on the exhaust hole plug 121.

  Next, a sealing method in this embodiment will be described. First, as illustrated in FIG. 1C, an integrated sealing part is prepared by arranging a glass adhesive layer 123 made of a low melting point glass frit (frit glass: glass powder) on one surface of a perforated part 122. . The production of the sealing part will be described. As described above, a plate member made of a material to be the perforated part 122 is prepared, the plate member is processed by a known etching process, and a plurality of perforated parts are connected at the connecting portion. It is assumed that it is connected. These are then subjected to wet hydrogen treatment to form thin oxide films on both sides. According to the wet hydrogen treatment in a hydrogen atmosphere containing water vapor, a thin oxide film mainly composed of chromium oxide can be formed on both surfaces where the 426 alloy is exposed.

  Next, as described above, a frit glass layer made of a frit glass paste is formed on one side of a sheet where a plurality of components having oxide films formed on both sides are connected by a known screen printing method. As described above, the frit glass is made of a glass material that gives priority to the consistency of expansion that occurs in the bonding with the glass constituting the substrate 101. Here, a frit glass layer made of a frit glass paste may be formed on the other surface by a known screen printing method. Thereafter, the temperature is raised to a temperature at which the formed frit glass layer is melted to remove the binder contained in the paste. Finally, a plurality of sealing parts (perforated parts 122) in which the glass adhesive layer 123 is formed are obtained by cutting the connecting parts and cutting each part.

  Next, the sealing part (perforated part 122) prepared and prepared as described above is simultaneously bonded to the portion of the exhaust hole 109 previously formed in the substrate 101 in the step of sealing the upper container and the substrate. Fixed. At this time, the exhaust hole 109 is made continuous with the hole of the perforated component 122. This adhesive fixing is a state in which the glass adhesive layer 123 of the perforated component 122 is in contact with the substrate 101 in the exhaust hole 109 portion, similarly to the frit glass (sealing layer 110) used for sealing the upper container and the substrate. The lead-free glass used for the glass adhesive layer 123 is melted.

  At this time, the heating temperature for bonding is a relatively high temperature of around 480 ° C. in order to obtain sufficient melting of the glass bonding layer 123, but in this step, there is no cooling part such as an O-ring, and the entire workpiece Is heated uniformly, and there is no temperature limitation as much as the sealing step of the exhaust hole plug. For this reason, the glass material used for the glass adhesive layer 123 can be a material having a relatively high softening point, and may be the same as the frit glass used for sealing the upper container.

  For example, the above-described bonding process of the perforated component 122 is performed in a uniform thermal environment such as a belt furnace. For this reason, there is no thermal distortion caused by a local temperature difference, and the perforated component and the substrate can be bonded reliably.

  On the other hand, a conventionally used exhaust hole plug 121 is prepared, and as shown in FIG. 1D, a lead-free low melting point having a softening point in the range of 250 to 400 ° C. on one surface of the exhaust hole plug 121. A glass adhesive layer 124 made of glass frit (frit glass) is formed to form a sealing component. The glass adhesive layer (exhaust hole side adhesive layer) 124 may be formed by coating by a known screen printing method. Further, since the printed glass adhesive layer is made of a paste material, it is necessary to remove the binder. For example, the glass adhesive layer is calcined at a temperature of about 450 ° C. As a material for the exhaust hole plug, 426 alloy with a plate thickness of about 0.18 mm is generally used, but it has a thermal expansion characteristic from metal, glass, and ceramic according to the stress generated when bonding. An appropriate material may be selected and used.

  Next, as described above, with respect to the fluorescent display device in which the perforated component 122 is bonded to the exhaust hole 109 portion of the substrate 101 and the perforated component 122 is fixed to the substrate 101 by the glass adhesive layer 123, FIG. 7 is used to perform evacuation in the envelope and sealing of the exhaust hole 109 with the exhaust hole plug 121. First, exhaust is performed by connecting an exhaust head around the exhaust hole 109 of the substrate 101. In this exhaust, as is well known, the envelope is heated to degas inside the envelope.

  After evacuating the inside of the envelope to a predetermined pressure as described above, the sealing component is disposed on a push-up rod that is disposed in the exhaust head and incorporates the heating mechanism, and the heating mechanism is The exhaust hole plug is heated to about 430 ° C. to melt the glass adhesive layer 124. At this time, the encapsulated gas is removed at the same time by melting glass as an adhesive in a vacuum.

  The heating temperature may be a temperature at which the frit glass (low-melting glass material) constituting the glass adhesive layer 124 is melted. Here, according to the method already described with reference to FIG. 7, the push-up bar is operated to heat the sealing component and bring it into contact with the perforated component 122 already bonded. Since the heating time in contact is short, there is no effect on the cooling of the O-ring. After the sealing part (exhaust hole plug) is brought into contact with the perforated part, the heating mechanism is stopped and the glass adhesive layer 124 is cooled and solidified. Through these steps, the exhaust hole plug 121 and the perforated component 122 are bonded by the glass adhesive layer 124, and the exhaust hole 109 is sealed by the exhaust hole plug 121.

  According to the present embodiment, the thermal expansion characteristic of the lead-free glass adhesive layer 124 in the melt bonding matches the thermal expansion characteristic of the substrate 101 in the thermal environment where the local temperature difference occurs as described above. Even if not, the stress that may occur between them is absorbed by the physical extension, shrinkage, and deformation of the perforated component 122. As a result, for example, even when the glass adhesive layer 124 having different thermal expansion characteristics is used, a hermetically sealed state can be stably obtained.

When the thermal expansion coefficient of the glass adhesive layer 124 is in the range of 70 to 90 × 10 ⁻⁷ / ° C., it has been confirmed that sealing can be performed without any problems without occurrence of cracks. On the other hand, when the exhaust hole plug 121 is directly bonded to the substrate 101 without using the perforated component 122, if a lead-free glass material is used with a relatively high softening point and the consistency of thermal expansion characteristics cannot be adjusted, It cannot withstand the stress generated by the difference between local thermal strain and the thermal expansion characteristics of the material, cracks, etc. occur, leading to a vacuum leak. Thus, by using the perforated component 122, it becomes possible to use a lead-free glass material having a higher softening point and complete thermal expansion characteristic consistency as a sealing material, and a range of material selection is possible. Become wider.

  In addition, according to the present embodiment, the exhaust hole plug 121 and the perforated part 122 are used and bonded with the low melting point glass. Further, it is not necessary to previously form a metallized layer (metal layer) or the like, and the manufacturing process is not increased. Further, as is clear from the manufacturing example described above, the perforated component 122 is easy to mass-produce at low cost. In addition, the low-melting glass used does not contain lead and can be made of materials that replace the main components with bismuth, tin, phosphorus, etc., so products that are environmentally friendly, such as conforming to the RoHS Directive, are produced. be able to.

  By the way, the outer shape of the perforated component 122 is not limited to a circular shape, and may be an irregular shape such as a rectangle or a polygon. Further, the opening provided in the central portion of the perforated component 122 does not need to match the shape of the exhaust hole 109 and may be other shapes than the circular shape. However, it is desirable that the opening provided in the center of the perforated component 122 is formed wider than the exhaust hole 109.

[Embodiment 2]
Next, Embodiment 2 of the present invention will be described with reference to FIG. FIG. 3 is a cross-sectional view showing a partial configuration of the fluorescent display device according to Embodiment 2 of the present invention. In the fluorescent display device according to the present embodiment, a ring-shaped perforated part 322 made of a glass plate is provided between the substrate 101 and the exhaust hole plug 121 in the exhaust hole 109, and the perforated part 322 is made of glass. An adhesive layer (substrate-side adhesive layer) 123 is adhered to the substrate 101, and the perforated component 322 and the exhaust hole plug 121 are adhered to each other by a glass adhesive layer (exhaust hole plug-side adhesive layer) 124. . The perforated part 322 may be made of ceramic. Other configurations are the same as those in the first embodiment, and a description thereof will be omitted.

  The perforated component 322 is made of, for example, an aluminosilicate glass having a thermal expansion coefficient of 88 × 10 −7 / ° C., and a square perforated plate having a thickness of 0.6 mm having a circular opening with a diameter of 2 mm at the center. It is. The perforated part 322 configured as described above can be easily mass-produced by cutting a larger glass plate into chips by a well-known scribe cutting, dicing or etching process, for example. is there.

  In addition, since glass originally has a brittle property, if excessive stress accumulates, it is easy to reach a crack. Therefore, a glass material used as the perforated part 322 has a thermal expansion coefficient that is not significantly different from that of soda lime glass as a base material to be bonded, but the thermal expansion coefficient is 70 to 90 × 10 −7 / For example, aluminosilicate glass, zinc borosilicate glass, or Super White glass manufactured by Schott Corporation can be used. In addition, since ceramic materials are not as brittle as glass, the allowable range of usable thermal expansion coefficients is somewhat widened. For example, alumina or forsterite can be used as the material.

  It should be noted that the material and thermal expansion coefficient of the perforated component 322 are selected, and the stress opposite to the stress generated as a result of sealing the glass adhesive layer 124 and the exhaust hole plug 121 to be sealed thereon is previously created as a base. Therefore, the stress generated when the exhaust hole plug 121 is sealed can be offset.

  In this case, for example, when compressive stress is generated due to the adhesion of the exhaust hole plug 121, the perforated parts 322 that generate tensile stress are created in advance as a base so that the two cancel each other when the exhaust hole plug 121 is adhered. To work. Specifically, since not only the thermal expansion coefficient of the adhesive layer 124 but also the difference in the thermal expansion coefficients of the exhaust hole plug 121 and the adhesive layer 124 and the base material when the adhesive layer 124 is solidified and fixed, In the case of a material having non-linear thermal expansion characteristics such as 426 alloy, the temperature (assumed by the softening point, yield point, etc.) fixed by the adhesive layer 124 becomes a problem.

  The temperature to be fixed depends on the softening point of the adhesive layer 124 or the like, but determines the characteristics of the holed part 322 depending on whether the fixed stress state is compression or tension. For example, when an exhaust hole plug 121 is made of 426 alloy (426 alloy) and an adhesive (frit glass a) having a thermal expansion coefficient α of 80 × 10 −7 ° C. that is solidified around 400 ° C. (assumed solidification temperature A) is generated. When a simple soda lime glass is used as a base, the stress is a compressive stress. In this case, if a material having a smaller thermal expansion coefficient α than the glass constituting the substrate 101 is used for the perforated part 322, a reverse stress is created in advance. The stress at the time of adhesion of the exhaust hole plug 121 can be offset (see FIG. 2).

  On the other hand, when using a low adhesive (frit glass b) with a temperature of solidification around 300 ° C. (assumed solidification temperature B), the thermal expansion coefficient α of the 426 alloy changes even if the thermal expansion coefficient α of the adhesive is the same. The direction of the stress is reversed (see FIG. 2). Thus, when the thermal expansion characteristic is non-linear, the thermal expansion cannot be specified unless the temperature is specified. In the present embodiment, since the perforated component 322 is made of glass, it is not necessary to form an oxide film on the bonding surface between the glass bonding layer 123 and the glass bonding layer 124. This is the same when the perforated component 322 is made of ceramic.

  Next, a sealing method in this embodiment will be described. First, a sealing component in which a glass adhesive layer 123 made of lead-free low-melting glass is disposed on one surface of the perforated component 322 is prepared. The production of this sealing part will be described. As described above, a glass plate made of a material to be the perforated part 322 is prepared, and for each region to be a plurality of perforated parts 322 to be described later, for example, a diameter is prepared. A 2 mm through hole is formed. The plurality of through holes can be formed using, for example, a drill. Also, a known etching process or ultrasonic machining may be used.

  Next, a paste layer (frit glass layer) of frit glass (lead-free low melting point glass) is formed on one surface of a glass plate in which through holes are formed in each region to be an individual perforated part by a known screen printing method. Form. The pattern of the frit glass layer to be the glass adhesive layer 123 is formed in a circle around the hole in the perforated plate having a square outer shape. This is because the stress is less likely to be concentrated when the bonding surface is circular rather than rectangular. As described above, the frit glass layer serving as the glass adhesive layer 123 is made of a glass material giving priority to the consistency of the thermal expansion characteristics with the glass constituting the substrate 101.

  Thereafter, the temperature is raised to a temperature at which the formed frit glass layer is melted to remove the binder contained in the paste. Finally, the glass plate on which the plurality of perforated parts are made is cut by scribe cutting and separated into individual regions, whereby a plurality of perforated parts 322 provided with the glass adhesive layer 123 are obtained. In addition, the perforated component 322 made of ceramic can be manufactured in the same manner using a ceramic plate.

  Thereafter, in the same manner as in the first embodiment, the perforated component 322 is bonded to the exhaust hole 109 of the substrate 101, and then the inside of the envelope is exhausted, and the other surface of the perforated component 322 is disposed. If the exhaust hole plug 121 is adhered to the glass adhesive layer 124, the exhaust hole 109 is sealed by the exhaust hole plug 121.

  Also in the present embodiment, even if the thermal expansion characteristics of the glass adhesive layer 124 in such melt bonding are not matched with the thermal expansion characteristics of the substrate 101, the stress that can be generated between them is a perforated component. 322 is absorbed (offset). As a result, for example, even when the glass adhesive layer 124 having different thermal expansion characteristics is used, a hermetically sealed state can be stably obtained. When the thermal expansion coefficient of the glass adhesive layer 124 is in the range of 70 to 90 × 10 −7 / ° C., it has been confirmed that sealing can be performed without any problem in the absence of cracks.

  On the other hand, when the exhaust hole plug 121 is directly bonded to the substrate 101 without using the perforated part 322, if a lead-free glass material is used while the softening point is relatively high and the consistency of the thermal expansion characteristics cannot be adjusted, It cannot withstand the stress generated by the difference between local thermal strain and the thermal expansion characteristics of the material, cracks, etc. occur, leading to a vacuum leak. Thus, by using the perforated component 322, the restriction on the softening point and thermal expansion coefficient of the material used for bonding (sealing) the exhaust hole plug 121 is reduced, and the range of material selection becomes wider.

  In addition, according to the present embodiment, the exhaust hole plug 121 and the perforated part 322 are used and bonded with the low melting point glass, so that the exhaust hole 109 of the substrate 101 is attached to the portion as in the case of bonding with the solder. Further, it is not necessary to form a metallized layer or the like in advance, and the manufacturing process is not increased. Moreover, the perforated component 322 is easily mass-produced as is apparent from the above-described manufacturing example. In addition, the low-melting glass used does not contain lead and can use lead-free materials that replace the main components with Bi, Sn, P, etc., so products that are environmentally friendly, such as conforming to the RoHS directive, can be used. Can be produced.

[Embodiment 3]
Next, Embodiment 3 of the present invention will be described with reference to FIG. FIG. 4 is a cross-sectional view showing a partial configuration of the fluorescent display device according to Embodiment 3 of the present invention. In the fluorescent display device according to the present embodiment, a ring-shaped perforated part 122 made of a metal material such as 426 alloy is provided between the substrate 101 and the exhaust hole plug 121 in the exhaust hole 109 portion. The component 122 is bonded to the substrate 101 by the glass adhesive layer 123, and the perforated component 122 and the exhaust hole plug 121 are bonded by the metal adhesive layer (exhaust hole plug side adhesive layer) 424. The metal adhesive layer 424 is made of, for example, a lead-free solder material. The exhaust hole plug 121 is bonded to the perforated part 122 with a metal adhesive layer 424, and seals the exhaust hole 109 continuous with the hole part of the perforated part 122. Other configurations are the same as those in the first and second embodiments, and a description thereof will be omitted.

  In the third embodiment, an oxide film (not shown) is formed on the surface of the perforated component 122 on the side of the glass adhesive layer 123 in order to improve adhesion with low-melting glass (lead-free). On the other hand, a metal layer (not shown) for improving solder wettability such as gold, silver, nickel, etc. is provided on the surface of the perforated component 122 on the side of the metal adhesive layer 424 so that the lead-free solder can be easily joined. Is formed.

  The glass adhesive layer 123 is a lead-free low-melting glass having a softening point of about 350 to 450 ° C. and a thermal expansion coefficient of about 70 to 90 × 10 −7 / ° C. The glass adhesive layer 123 may be any lead-free glass material that does not generate stress such as cracks with the substrate 101 when it is melted and bonded, and for example, the upper container 108 and the substrate. The same lead-free low melting point glass as the sealing layer 110 for sealing 101 may be used. These lead-free low-melting glasses include, for example, those in which Pb, which is a main material for lowering the melting point, is replaced with Bi, Sn, P, or the like.

  Next, a sealing method in this embodiment will be described. First, as described in the first embodiment, a metal layer is formed on one surface of the perforated component 122, and a glass adhesive layer 123 made of frit of low melting point glass (lead-free material) is disposed on the other surface. Prepare integrated sealing parts. The production of the sealing part will be described. As described above, a plate member made of a material to be the perforated part 122 is prepared, the plate member is processed by a known etching process, and a plurality of perforated parts are connected at the connecting portion. It is assumed that it is connected. In this way, a gold layer (metal layer) is formed on one surface by plating in a state where a plurality of perforated parts are connected. Next, these are subjected to wet hydrogen treatment to form a thin oxide film on the other surface. According to wet hydrogen treatment in a hydrogen atmosphere containing water vapor, for example, a thin oxide film mainly composed of chromium oxide can be formed on the other surface where the 426 alloy is exposed.

  Next, as described above, a frit glass made of a frit glass paste is formed by a known screen printing method on the oxide film forming surface (the other surface) of a sheet in which a plurality of components on which a gold plating layer and an oxide film are formed are connected. Form a layer. As described above, the frit glass is made of a glass material that gives priority to the consistency of expansion that occurs in the bonding with the glass constituting the substrate 101. Thereafter, the temperature is raised to a temperature at which the frit glass of the formed frit glass layer is melted, and the binder contained in the paste is removed. Finally, a plurality of sealing parts (perforated parts 122) in which the glass adhesive layer 123 is formed are obtained by cutting the connecting portions and cutting each part. Note that the gold layer is not limited to plating, and may be formed by sputtering or vapor deposition. In this case, the gold layer may be formed after the substrate-side adhesive layer is formed.

  Next, the sealing component (perforated component 122) prepared and prepared as described above is bonded and fixed to the exhaust hole 109 of the substrate 101. At this time, the exhaust hole 109 is made continuous with the hole of the perforated component 122. This bonding and fixing is performed at the same time in the process of sealing the substrate and the upper container, and the glass bonding layer 123 of the perforated component 122 is in contact with the substrate 101 in the exhaust hole 109 portion, and the glass bonding layer 123 is fixed. This is done by melting the glass material used. At this time, the heating temperature for bonding is a relatively high temperature of around 480 ° C. However, in this process, there is no cooling part such as an O-ring, and the entire workpiece is heated uniformly, so the exhaust hole plug There is no temperature limit as much as the sealing process. For this reason, the glass material of the glass adhesive layer 123 can be used even with a material having a relatively high softening point.

  For example, the above-described bonding process of the perforated component 122 is performed in a uniform thermal environment such as a belt furnace. For this reason, there is no thermal distortion caused by a local temperature difference, and the perforated component and the substrate can be bonded reliably. The perforated parts can be bonded in advance using a step of firing a component on the substrate such as a phosphor screen or a grid before the upper container and the substrate are bonded.

  On the other hand, a conventionally used exhaust hole plug 121 is prepared, and a metal adhesive layer 424 made of a lead-free solder material is formed on one surface of the exhaust hole plug 121 to form a sealing component. The metal adhesive layer 424 may be formed by, for example, applying a solder paste or immersing in a solder bath using flux.

  Next, as described above, with respect to the fluorescent display device in which the perforated component 122 is bonded to the exhaust hole 109 portion of the substrate 101 and the perforated component 122 is fixed to the substrate 101 by the glass adhesive layer 123, FIG. 7 is used to perform evacuation in the envelope and sealing of the exhaust hole 109 with the exhaust hole plug 121. First, exhaust is performed by connecting an exhaust head around the exhaust hole 109 of the substrate 101. In this exhaust, as is well known, the envelope is heated to about 300 ° C. to degas inside the envelope.

  After the inside of the envelope is evacuated to a predetermined pressure as described above, the sealing component is disposed on the push-up rod that is disposed in the exhaust head and incorporates the heating mechanism, and the heating mechanism is The exhaust hole plug is heated to operate, and the metal adhesive layer 424 is melted. At this time, by removing lead-free solder as the metal adhesive layer 424, the gas contained in the lead-free solder is removed at the same time.

  Thereafter, the molten metal adhesive layer 424 is brought into contact with the gold layer forming surface of the holed part 122 already bonded by operating the push-up rod while continuing to heat the sealing part. The heating temperature may be a temperature at which the lead-free solder material constituting the metal bonding layer 424 melts, for example, about 250 ° C. At this temperature, the temperature is lower than the baking temperature of the envelope, and the O-ring 711 of the exhaust head 710 is not damaged. After the sealing part (exhaust hole plug) is brought into contact with the perforated part, the heating mechanism is stopped, and the metal adhesive layer 424 is cooled and solidified. Through these steps, the exhaust hole plug 121 and the perforated component 122 are bonded by the metal adhesive layer 424, and the exhaust hole 109 is sealed by the exhaust hole plug 121.

  In the above-described soldering, a gold layer is formed on the surface of the perforated component 122, so that the solder material constituting the metal adhesive layer 424 is easily wetted without using solder flux or the like. A metal bond is formed. When the solder flux is used, the gas generated by heating adversely affects the components of the fluorescent display device arranged inside the envelope, but this can be prevented by using a gold layer (metallized layer).

  According to the present embodiment, when the exhaust hole 109 is sealed with the exhaust hole plug 121, it is only necessary to heat the solder material constituting the metal adhesive layer 424 to a temperature at which the solder material is melted. It can be done without too high a temperature. Further, even when the thermal expansion characteristics of the solder material used for the metal bonding layer 424 in such melt bonding is not consistent with the thermal expansion characteristics of the substrate 101, the stress that may be generated between them is perforated component 122. It is absorbed by the physical elongation, shrinkage and deformation of the.

  In particular, since the thickness of the perforated part is sufficient for several μm of the thin film, it is effective in absorbing stress. As a result, for example, even when the metal adhesive layer 424 made of a solder material having different thermal expansion characteristics is used, a hermetically sealed state can be stably obtained. In addition, it is possible to use a wider range of adhesives by forming a perforated part in advance with a material that generates stress in a direction that cancels out the stress generated by adhering the exhaust hole plug. .

  Conventionally, when sealing the exhaust hole plug with a metal such as solder, it has been necessary to metallize a metal thin film around the exhaust hole part of the substrate, which is difficult to put into practical use due to poor productivity. According to the form, a plurality of perforated parts 122 produced by standardizing the size and metallizing each surface by a multi-chamfer method are produced in advance in an efficient and large amount, and this base material (metallized) Since the perforated component is bonded to the substrate with low melting point glass, it is no longer necessary to form a metallized layer or the like directly in the exhaust hole 109 portion of the substrate 101. As a result, a metal bonding material such as lead-free solder can be used as a sealing material for the exhaust hole plug without impairing productivity. In addition, this makes it possible to reduce both the environmental burden and ensure the reliability of the vacuum vessel.

  By the way, the metal adhesion layer 424 is not limited to an alloy such as a solder material, but may be composed of a single metal material having a low melting point such as tin or indium. The metal adhesion layer 424 only needs to be made of a low melting point metal material (including an alloy) that melts at a temperature of 400 ° C. or lower. Of course, the glass adhesive layer 123 that is melted and bonded is a low-melting glass material that melts at a temperature that does not melt the substrate 101 and the perforated component 122 constituting the envelope. The same applies to other embodiments.

[Embodiment 4]
Next, Embodiment 4 of the present invention will be described with reference to FIG. FIG. 5 is a cross-sectional view showing a partial configuration of the fluorescent display device according to Embodiment 4 of the present invention. In the fluorescent display device according to the present embodiment, a metal material such as 426 alloy is formed between the substrate 101 and the exhaust hole plug 121 in the exhaust hole 109, and nickel (Ni) or aluminum (Al ) And a ring-shaped perforated component 122 in which a clad layer 522 such as copper (Cu) is formed. The perforated component 122 adheres to the substrate 101 by the glass adhesive layer 123, and the clad layer 522 of the perforated component 122. And the exhaust hole plug 121 are bonded to each other by a metal adhesive layer 424.

  The purpose of using the clad material for the perforated component 122 is that the side to be bonded to the glass substrate 101 is made of a material that is relatively close to the thermal expansion coefficient of the substrate 101, such as a 426 alloy or 50, 52 alloy. Secure a stable adhesion, and on the clad side, a metal adhesive layer (exhaust hole plug side adhesive layer) 424 and a material having thermal expansion, or a material having a role of a stress absorbing layer and a solder joint layer are arranged, It is to secure the adhesion reliability of the exhaust hole plug. When using 426 alloy or the like, as described above, the surface is oxidized in order to improve the wettability with the glass adhesive layer 123. Other configurations are the same as those in the first to third embodiments, and a description thereof will be omitted.

  In the present embodiment, a metal adhesive layer 424 made of lead-free solder or the like is formed in advance on the cladding layer 522 of the perforated component 122, and in this state, the perforated component 122 is attached to the glass substrate by the glass adhesive layer 123. Adhere to 101. Note that the glass adhesive layer 123 may be formed in advance on the portion of the exhaust hole 109 of the glass substrate 101, and the perforated component 122 may be adhered to the glass adhesive layer 123 in this state. Thereafter, in the sealing step, the exhaust hole plug 121 is brought into contact with the metal adhesive layer 424 and heated to melt the metal adhesive layer 424 and adhere the exhaust hole plug 121 to the perforated component 122. In this sealing process, since the heat treatment is performed in a vacuum exhaust state, the metal adhesive layer 424 is suppressed from being oxidized, and the molten metal adhesive layer 424 is stably adhered to the exhaust hole plug 121. .

  This embodiment is also the same as the embodiment described above, and when the exhaust hole 109 is sealed by the exhaust hole plug 121, the solder material constituting the metal adhesive layer 424 is heated to a temperature at which it melts. Therefore, the heating can be performed without increasing the temperature. Further, even when the thermal expansion characteristics of the solder material in such melt bonding are not consistent with the thermal expansion characteristics of the substrate 101, the stress that can be generated between them is absorbed by the perforated component 122. Become. As a result, for example, even when the metal adhesive layer 424 made of a solder material having different thermal expansion characteristics is used, a hermetically sealed state can be stably obtained.

  Also in this embodiment, since the exhaust hole plug 121 and the perforated component 122 are used and bonded with solder and low melting point glass, a thin metallized layer is previously formed in the exhaust hole 109 portion of the substrate 101. Etc., and the manufacturing process is not increased. Moreover, the perforated part 122 is easy to mass-produce. As in the present embodiment, the perforated component 122 is composed of a plurality of metal layers (including a clad layer and a plating layer), thereby absorbing stress and improving bonding (wetting) properties with an adhesive. A plurality of characteristics can be improved.

  As described above, a stress adjusting function can be added by providing a clad layer of Ni, Al, Ti, Cu, or an alloy material having an appropriate thermal expansion coefficient. Moreover, the function which improves the joining (wetting) property with an adhesive material can be added by making it the perforated component in which the Au plating layer is formed in the surface which consists of material which a solder does not wet easily. Further, in order to enhance the addition of a solder bonding material and the stress adjustment function, it is possible to make a perforated part using a clad material in which a plurality of layers of three or more layers are laminated.

[Embodiment 5]
Next, Embodiment 5 of the present invention will be described with reference to FIG. FIG. 6 is a cross-sectional view showing a partial configuration of the fluorescent display device according to Embodiment 5 of the present invention. In the fluorescent display device according to the present embodiment, a ring-shaped hole made of a glass plate and having a metal layer 622 formed on one surface between the substrate 101 and the exhaust hole plug 121 in the exhaust hole 109 portion. A perforated part 322 is provided, the perforated part 322 is adhered to the substrate 101 by the glass adhesive layer 123, and the metal layer 622 and the exhaust hole plug 121 of the perforated part 322 are adhered by the metal adhesive layer 424. It is. The perforated part 322 may be made of ceramic. Other configurations are the same as those in the first embodiment, and a description thereof will be omitted.

  In the present embodiment, a metal layer 622 that can be bonded to a solder material is required on the surface on the exhaust hole plug side of the perforated component 322 so that bonding can be performed with solder (metal adhesive layer 424). . The metal layer 622 only needs to be made of a metal material such as gold, silver, nickel, or tin. Moreover, it is good also as a laminated structure which combined these metals. The metal layer 622 may be formed by, for example, a sputtering method, a vapor deposition method, a plating method, or the like. In this embodiment, since the perforated component 322 is made of glass, it is not necessary to form an oxide film on the glass adhesive layer 123 side. This is the same when the perforated component 322 is made of ceramic.

  Next, a sealing method in this embodiment will be described. First, as described in the second embodiment, the metal layer 622 is formed on one surface of the perforated component 322, and the glass adhesive layer 123 made of a low-melting glass frit is disposed on the other surface. Prepare the parts to be sealed. The production of the sealing part will be described. As described above, a glass plate made of a material to be the perforated part 322 is prepared, and for each individual region to be the perforated part 322 to be described later, for example, a diameter of 2 mm is prepared. Through-holes are formed.

  Next, a metal layer is formed, for example, by vapor deposition on one surface of the glass plate in which through holes are formed for each individual region of the perforated part. Next, a frit glass layer made of a frit glass paste is formed on the other surface of the glass plate by a known screen printing method. As described above, the frit glass is made of a glass material that prioritizes the consistency of thermal expansion characteristics with the glass constituting the substrate 101. The frit glass layer is baked to remove the binder, and then the glass plate is cut by scribe cutting and separated into individual regions, whereby a plurality of perforated parts 322 in which the glass adhesive layer 123 is formed are obtained. In addition, the perforated component 322 made of ceramic can be manufactured in the same manner using a ceramic plate.

  Thereafter, the perforated component 322 is bonded to the exhaust hole 109 of the substrate 101 in the same manner as in the third embodiment described above, and then the inside of the envelope is exhausted and the metal layer 622 of the perforated component 322 is exhausted. If the exhaust hole plug 121 is bonded to the metal adhesive layer 424, the exhaust hole 109 is sealed by the exhaust hole plug 121.

  According to the present embodiment, when the exhaust hole 109 is sealed with the exhaust hole plug 121, it is only necessary to heat the solder material constituting the metal adhesive layer 424 to a temperature at which the solder material is melted. It can be done without too high a temperature. Even when the thermal expansion characteristic of the solder material in such melt bonding is not consistent with the thermal expansion characteristic of the substrate 101, the coefficient of thermal expansion of the perforated component 322 is adjusted as described above, and the solder material is sealed on this. A stress opposite to the stress generated as a result of sealing the metal adhesive layer 424 to be attached and the exhaust hole plug 121 is created in advance as a base, and can be generated between the exhaust hole plug 121 and the sealing member. The stress is absorbed (offset) by the perforated part 322. As a result, for example, even when the metal adhesive layer 424 made of a solder material having different thermal expansion characteristics is used, a hermetically sealed state can be stably obtained.

  Further, conventionally, when sealing the exhaust hole plug with a metal such as solder, it has been necessary to metallize around the exhaust hole part of the substrate, which is difficult to put into practical use due to poor productivity. According to this, a plurality of perforated parts 322 produced by standardizing the size and metalizing each surface by a multi-chamfer method are produced in advance in an efficient and large quantity, and the base material (metallized perforated part 322 made into parts) is made. ) Is bonded to the substrate 101 with low-melting glass, so that it is no longer necessary to form a metallized layer or the like directly in the exhaust hole 109 portion of the substrate 101. As a result, a metal bonding material such as lead-free solder can be used as a sealing material for the exhaust hole plug 121 without impairing productivity. In addition, this makes it possible to both reduce the environmental burden and ensure the reliability of the vacuum vessel.

  Here, the case where the metal layer 622 formed on the perforated component 322 is one layer has been described, but the metal layer 622 may be a laminated film of two or more layers. For example, by laminating a ductile material such as Al or Cu as a base material on the base of the soldering metal layer, it is possible to prevent cracks when stress is applied. In addition, the exhaust hole plug material has been described using 426 alloy as a representative example, but instead of this, materials suitable for metal materials, glass, and ceramic materials taken up as perforated parts may be used. By selection and combination, the stress generated at the time of sealing can be appropriately eliminated.

  In the above description, a so-called tripolar fluorescent display device including an anode, a grid, and a filament has been described as an example. However, the present invention is not limited to this, and a phosphor layer such as a bipolar fluorescent display device that does not include a grid. Needless to say, the same applies to other fluorescent display devices having an anode formed therein.

It is sectional drawing which shows the structure of the fluorescence display apparatus in Embodiment 1 of this invention. It is sectional drawing which shows a partial structure of the fluorescence display apparatus in Embodiment 1 of this invention. It is sectional drawing which shows a partial structure of the fluorescence display apparatus in Embodiment 1 of this invention. It is sectional drawing which shows the partial structure of the fluorescence display apparatus in embodiment of this invention. It is a characteristic view which shows the relationship of the thermal expansion of each material when adhere | attaching an exhaust hole plug. It is sectional drawing which shows a partial structure of the fluorescence display apparatus in Embodiment 2 of this invention. It is sectional drawing which shows a partial structure of the fluorescence display apparatus in Embodiment 3 of this invention. It is sectional drawing which shows a partial structure of the fluorescence display apparatus in Embodiment 4 of this invention. It is sectional drawing which shows a partial structure of the fluorescence display apparatus in Embodiment 5 of this invention. It is explanatory drawing for demonstrating the method of evacuating the inside of an envelope by connecting an exhaust head to the exhaust hole provided in the envelope.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 101 ... Board | substrate, 102 ... Wiring layer, 103 ... Insulating layer, 103a ... Through-hole, 104 ... Anode electrode, 105 ... Phosphor layer, 106 ... Grid, 107 ... Filament, 108 ... Upper container, 109 ... Exhaust hole, 110 ... Sealing layer, 111 ... electrode, 112 ... lead, 121 ... exhaust hole plug, 122 ... perforated part, 123 ... glass adhesive layer (substrate side adhesive layer), 124 ... glass adhesive layer (exhaust hole plug side adhesive layer).

Claims (5)

An envelope made of glass containing therein an anode formed with a phosphor layer and an electron emission source;
An exhaust hole formed in the envelope;
A perforated component bonded to the exhaust hole portion of the envelope with a substrate-side adhesive layer made of lead-free glass;
A fluorescent display comprising at least an exhaust hole plug that is bonded to the perforated part with an exhaust hole stopper side adhesive layer made of a lead-free material and seals the exhaust hole continuous with the hole part of the perforated part. apparatus. The fluorescent display device according to claim 1,
The fluorescent display device, wherein the perforated part is made of metal. The fluorescent display device according to claim 1,
The said perforated component is comprised from the material selected from glass and ceramic. The fluorescence display apparatus characterized by the above-mentioned. The fluorescent display device according to any one of claims 1 to 3,
The exhaust hole plug side adhesive layer is made of lead-free glass. The fluorescent display device according to any one of claims 1 to 3,
The exhaust hole plug side adhesive layer is made of a metal not containing lead that melts at a temperature of 400 ° C. or lower.

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