KR100364059B1 - Method for vacuum sealing of flat panel display, getter loading method and structure thereof - Google Patents

Abstract

The present invention relates to a technique for high vacuum mounting a flat panel display, and a getter mounting method and mounting structure according to the method, wherein the cathode glass plate (10) and the anode glass plate (3) are heated in a high vacuum chamber, and the lower support plate (20) (30). Vacuum in-line mounting through frit melting by the method, forming a getter seat 11 'under the exhaust port 11 of the cathode glass plate 10, and a getter seat 11 Step 102 of adhering the frit adhesive 12 around the < RTI ID = 0.0 > ", < / RTI > a sealant 50 which can cover the getter seat 11 ' and entering the getter seat 11 ' Mounting a getter 60 of size 112; moving the getter 60 below the getter seat 11 ′; and heating the getter 60 by the getter heater 40. And the frit adhesive 12 is applied by the getter heater 40 to activate and lower the temperature of the getter heater 40. And a method of mounting a getter for a flat panel display comprising a step 114 of squeezing the sealing material 50 to the frit adhesive 12 and a getter seating on the back of the cathode glass plate 10 on which the cathode electrode is formed. The exhaust port 11 forming the portion 11 'is provided to provide a getter mounting structure for a flat panel display that activates and inserts a small disc or circular ring-shaped getter 60, thereby providing a cathode glass plate and an anode glass plate. It is for minimizing the degree of contamination inside the panel by outgassing that occurs when mounting by frit melting and when getter is activated, and thinly mount the getter inside the panel.

Description

Method for vacuum sealing of flat panel display, getter loading method and structure

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat panel display vacuum mounting technology for displaying image signals using an electron beam or plasma, a getter mounting method, and a mounting structure. A getter is mounted for flat panel display vacuum in-line mounting that allows the getter to be thinly mounted on the panel, and also reduces contamination inside the panel from out-gassing of impurities generated during frit melting or getter activation. It relates to a method and a mounting structure.

The flat panel display to which the present invention is applied includes a field emission display (hereinafter referred to as FED), a plasma display panel (hereinafter referred to as PDP), a vacuum fluorescent display (hereinafter referred to as VFD), and the like. A microelectronic display device in the form of a flat panel, which is one of the key element technologies in manufacturing such a flat panel display, is to form an initial high vacuum state inside the panel.

In particular, it is also very important for the FED or VFD to permanently maintain the initial high vacuum.

During the use of these displays, H2, O2, CO, CO2, and N2 from various components such as fluorescent screens or glass barrier ribs or spacers and frits inside the panel. As the impurities are outgassed, the amount of the impurities gradually increases.

Such impurities increase the discharge start voltage and decrease the luminous efficiency in the case of PDP. In the case of FED, the operating voltage for emitting electrons from the emitter is increased and the life time is shortened due to the arc phenomenon. In particular, impurities such as O 2 and H 20 may oxidize the cathode metal material.

As a result, one of the techniques to overcome in commercializing the FED is to narrow the field emitter array (FEA) corresponding to the cathode electrode and the phosphor screen corresponding to the anode electrode as small as 200 microns (μm). It should be close enough to each other and permanently mounted with high vacuum of 1 × 10-7 torr or higher.

The material used for vacuum mounting should be a transparent glass plate so that electrons emitted from the cathode emitting surface can transmit the light emitted when it hits the phosphor screen.

A problem with high vacuum glass mounting for FEDs is how to maintain the microspace given by a narrow gap of 200 μm between the rugged surface cathode radiation surface and the display screen at the same level of vacuum in the mounting vacuum chamber. In particular, it is important to secure such ultra-high vacuum degree in a short time for mass production. Also important is how permanently the initial vacuum degree is maintained.

The most reliable way to ensure the initial vacuum inside the panel of a flat panel display with microspace and complex geometries in a high vacuum state is the "vacuum in-line mounting" in which two glass plates are mounted inside the vacuum chamber. -line packaging "technology.

In addition, in order to maintain the high vacuum obtained as in the requirements of FED or VFD or to maintain the high purity of the plasma gas (Xe, Ne, etc.) used as in the requirements of PDP, outgassing from components There is a need for a technique for effectively gettering out-gassing impurities.

1 is a panel sectional view of a FED flat panel display equipped with a getter by a conventional mounting method.

The display device includes a lower cathode glass plate 1 having an electron emission electrode 2, an upper anode glass plate 3 coated with a fluorescent screen 4, a spacer 5 for supporting the two glass plates, and a vacuum. And a getter 7 for holding a vacuum.

Here, the connection between the cathode glass plate 1, the anode glass plate 3 and the exhaust pipe 6 is made by mounting using a frit glass paste adhesive 8 having a low melting temperature.

The process of forming the display device having such a structure is as follows.

A thin coating of the adhesive agent 8 along the circumferential edges of the two cathode glass plates 1 and the anode glass plate 3 on which the electron emission electrode 2 and the fluorescent screen 4 are formed, and then calcining at a temperature of about 420 ° C. pre-baking, aligning the pixels of the electron-emitting electrode 2 with the pixels of the fluorescent screen 4, and then post-baking them at a temperature range of 420 ° C. to melt sealing the two panels. Let's do it. Next, the exhaust glass tube 6 is melt-bonded in the same manner as before in the periphery of the hole 9 made in one corner of the cathode glass plate 1. Subsequently, the open portion of the glass tube 6 is connected to the exhaust port of the exhaust device, and then the inside of the panel is exhausted by using a high vacuum pump such as a turbomolecular pump (TMP), an ion pump, a CRYO pump, or the like.

At this time, the electric furnace surrounding the panel is heated to a temperature of about 200 ℃ to 400 ℃ to obtain ultra-high vacuum. Thus, when the final degree of vacuum is obtained, the middle part of the glass tube 6 is melted and cut to seal the panel by using a torch or a heater. Next, in order to maintain a vacuum, the getter 7 previously mounted at an appropriate position of the glass tube 6 is heated to be activated. On the other hand, the activation of the getter 7 may be performed just before melting and cutting the middle portion of the glass tube 6.

The prior art described above has the following problems.

Exhaust through the glass tube limits the exhaust conductivity so that the vacuum inside the panel is more than 100 times lower than the vacuum inside the chamber.

In addition, the glass components generated when the tube melts in the process of sealing the glass tube are trapped in the panel to contaminate the components inside the panel or lower the vacuum degree.

In the case of the PDP, such a vacuum decreases the purity of the plasma gas used, which in turn causes a change in operating voltage and a luminous efficiency, and since a single chamber is used, more than a few tens of hours are required to reach ultra-high vacuum. It takes

In addition, the volume of the display device may increase due to the getter mounted inside the exhaust pipe or the panel. In addition, when the evaporation getter is used, the electron emission and emission phenomenon may be reduced by the getter material deposited on the electrode or the screen. You will be limited. In addition, the outgassing that occurs when activating the getter causes contamination and reduced vacuum.

In recent years, in order to further improve the degree of vacuum inside the panel, two pieces of glass plates having frits pasted in advance are mounted on a holder in a vacuum chamber, and the glass is melted with a laser to attach a cathode glass plate and an anode glass plate. The "in-line" method is applied, but since it contacts the two glass plates first and then melts the adhesive, the contaminants that occur when the adhesive melts again become trapped inside the panel.

SUMMARY OF THE INVENTION The present invention has been made in view of these conventional problems, and it is possible to form the panel softly by measuring the sealing step and the mounting step of the getter on the cathode glass plate treated by the vacuum in-line mounting method, and to reduce the degree of contamination inside the panel. It is an object of the present invention to provide a getter mounting method and mounting structure according to a vacuum mounting for a flat panel display.

A getter mounting method for a flat panel display vacuum mounting of the present invention for achieving this purpose comprises the steps of forming a getter seating portion in the lower portion of the exhaust port of the cathode glass plate, adhering the frit adhesive around the getter seating portion, the getter seating portion Installing a getter of a size that fits into the getter seat on the sealant, moving the getter to the bottom of the getter seat, and heating and activating the getter by means of a getter heater; It comprises a step of lowering, heating and melting the frit adhesive by the getter heater, and compressing the sealing material to the frit adhesive, the getter mounting structure is formed on the back of the cathode glass plate on which the cathode electrode is formed To form a small disc or circular ring It is characterized by inserting after activating the getter.

1 is a cross-sectional view showing a conventional display panel;

Figure 2 is a cross-sectional view showing a vacuum in-line mounting and getter mounting structure of the embodiment of the present invention,

3 shows a vacuum in-line mount of an embodiment of the invention and Schematic process diagram showing the getter mounting method,

4 is a cross-sectional view showing one display panel according to the present invention;

5 is a plan view of the display panel of FIG. 4;

6 is a plan view showing another display panel according to an embodiment of the present invention;

FIG. 7 is a flowchart illustrating a process sequence for manufacturing the getter seating part and the exhaust port of the flat panel display panel of FIG.

<Description of the symbols for the main parts of the drawings>

10: cathode glass plate 20,30: upper, lower support plate

40: getter heater 50: sealing material

60: getter

Hereinafter, a getter mounting method and mounting structure for flat panel display vacuum in-line mounting of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a cross-sectional view of an apparatus using the getter mounting method for a flat panel display of one embodiment of the present invention, wherein the upper and lower support plates (graphite or thermally conductive substrates) 20 and 30 in a high vacuum sealing chamber are shown. The heat source 21, 31, such as a halogen or an ar lamp, an arc lamp, or a heating wire, is arranged on the outside thereof for heating. Before the anode / cathode glass plates 3 and 10 are mounted on their respective upper and lower support plates 20 and 30, a cleaning operation is carried out in a cleaning chamber connected via a transport. The upper upper support plate 20 is aligned with the cathode glass plate 10 while the anode glass plate 3 is moved in the X-Y-Z and the specific angle θ by the position adjuster 23. For mounting, a frit adhesive 8 preformed on the upper anode glass plate 3, the lower cathode glass plate 10, or both glass plates 3, 10 is post-baked by the heat source 21. After performing the process, the upper support plate 20 for supporting the upper anode glass plate 3 is adjusted by the positioner 23, moved downward to be coalesced, and then aligned. Such a cleaning and vacuum mounting apparatus has already been proposed (patent application No. 97-26696).

As described above, the getter is mounted on the panel manufactured by the conventional in-line type apparatus using the getter mounting structure of the embodiment of the present invention, and the mounting structure is one exhaust port 11 of the cathode glass plate 10. And a distribution hole 32 formed at a position facing the getter seating portion 11 'formed at the lower portion of the bottom surface, and the getter seating portion 11' of the lower support plate 30 installed at the lower portion of the cathode glass plate 10, It consists of a sealing material 50 for sealing the exhaust port 11 and a circular annular getter 60 seated on the upper surface of the sealing material (50).

In the above embodiment, the circular annular getter 60 is used, but the shape thereof may be used in various ways, such as a disc and a cylinder.

One or more exhaust ports 11 having seating portions 11 ′ may be formed in the cathode glass plate 10 without limitation, and a corresponding number of distribution holes 32 may be formed in the lower support plate 30. The getter 60 can be mounted by the getter heater 40 and the positioner 41.

In order to mount the getter by the getter mounting structure configured as described above, a small sealing material 50 of appropriate size for blocking the getter seating portion 11 'is placed on the getter heater 40 and the getter 60 on the sealing material 50. Position is moved by the positioner 41 of the getter heater 40 through the distribution hole 32 of the lower support plate 30 under the getter seat 11 '. The getter 60 moved as described above is activated by the heat source of the getter heater 40. Since the activation temperature is generally 500 ° C. or more, the temperature of the getter heater 40 is lowered to 450 ° C. or less before sealing after activation. The activated getter 60 is inserted into the getter seat 11 'and at the same time, the sealing material 50 is adhered and mounted by the adhesive 12 applied around the getter seat 11'. On the other hand, the adhesive 12 around the getter seat 11 'is used for heating the cathode before the getter 60 is mounted. It is baked through the heat source 31 or the getter activation heater 40.

Next, referring to Figs. 2, 3 and 4, the mounting method of the getter for a flat panel display of the embodiment of the present invention will be described.

First, before proceeding with the vacuum mounting operation of the lower cathode glass plate 10 on which the field emission electrode 2 is formed and the upper anode glass plate 3 on which the fluorescent screen 4 is applied, the frit paste adhesive 8 is first held in the air. (12) is applied along the edge of the anode glass plate (3) and around the getter seating 11 'of the cathode glass plate (10) exhaust port (11) and then pre-baking in an electric furnace to evaporate the solvent component. The operation is carried out at a temperature of 400-450 ° C. for 10-30 minutes. Two glass plates 10 and 3 are mounted in the cleaning chamber, followed by cleaning with ion beam, plasma gas and electron beam. The cathode glass plate 10 is cleaned by an ion beam or hydrogen plasma, and the anode glass plate 3 is cleaned by an electron beam. After the cleaning operation, the two glass plates 3 and 10 and the sealing material 50 are transferred to the mounting chamber in vacuum and initial heating state through the transfer chamber, and the upper and lower support plates 20 and 30 in the mounting chamber. ) And getter heater 40.

In the upper and lower support plates 20 and 30, as shown in FIG. 2, heat sources (halogen, argon lamp, heating wire, etc.) 21 and 31 arranged on the rear surface are provided, and the upper portion of the heat source 21 is provided. The alignment and coalescing of the two glass plates 3 and 10 is performed while moving in the XYZ and the specific angle θ by the mounted positioner 23.

Since the two glass plates 3 and 10 which are transferred are separated by a considerable distance (several centimeters) down and up, the two glass plates 3 and 10 can maintain the same degree of vacuum as the mounting chamber. For mounting, first, the frit adhesive 8 formed on the upper glass plate 3 or the lower glass plate 10 (or both glass plates) is directly radiated by the heat sources 21 and 31 or the upper and lower support plates. The frit adhesive 8 is melted by performing a post baking process by indirect heat transferred to the 20 and 30. Then wait until the components that are outgassed are sufficiently vented when the frit melts. When the outgassing stops and the vacuum degree is restored again, the upper support plate 20 supporting the upper glass plate 3 is moved by adjusting the positioner 23 to move down, merging with the lower glass plate 10, and then aligning and The mounting is completed by performing the bonding operation. Such a cleaning and vacuum mounting apparatus has already been proposed (patent application No. 97-26696).

Thus, the mounting of the two glass plate is made by a conventional vacuum in-line method, the getter mounting method of the embodiment of the present invention, the getter seating portion (11 ') is formed in the lower portion of the exhaust port 11 of the cathode glass plate (10) (101), applying (102) the frit adhesive (12) around the getter seat (11 ') of the anode glass plate (3) and the cathode glass plate (10), and fluorescing at a predetermined position in the cleaning chamber. A step 103 of mounting the anode glass plate 3 to which the screen 4 is applied, and the cathode glass plate 10 to which the FEA 2 is attached and the appropriate number of exhaust ports 11 are formed, are placed in a predetermined position in the washing chamber. Mounting (104) and washing (105) the anode glass plate (3) and the cathode glass plate (10) with a plasma and an electron beam by supplying hydrogen gas into the cleaning chamber and simultaneously applying a direct current or RF voltage; Each high vacuum pump (TMP, inno pump or CRYO pump) installed in these cleaning chambers Step 106 to exhaust the inside of the chamber, and to operate the TMP again to transfer the anode glass plate 3 and the cathode glass plate 10 to the mounting chamber from the cleaning chamber to the mounting chamber in the ultra-high vacuum and initial heating state ( 107, mounting 108 the anode glass plate 3 and the cathode glass plate 10 on the upper and lower support plates 20, 30, and FEA 2 and the anode on the cathode glass plate 10. 109 aligning the fluorescent screen 4 on the glass plate 3 and heating the anode glass plate 3 and the cathode glass plate 10 and evacuating the chamber, and the two glass plates 3, 10 being mutually A step of forming a panel by adhering while maintaining a microgap (110), and the step of mounting the sealing material 50 of the size that can cover the getter mounting portion (11 ') around the getter heater 40 (111), step (112) of mounting a getter (60) of a size that fits within the getter seat (11 ') on the sealant (50), and the getter (60). A step 113 of moving the lower getter seat 11 ', a step 114 of lowering the temperature of the getter heater 40 after heating and activating the getter 60 by the getter heater 40, and a panel And exhausting the inside of the chamber and simultaneously inserting the getter 60 into the getter seating portion 11 'and heating the lower support plate 30 to a predetermined temperature to compress the sealant 50 to the frit adhesive 12 (115). Mounting of the getter is completed.

In each of the above steps, the sealing material mounting step 111, the getter mounting step 112 may be advanced, or may be activated after placing the getter 60 on the getter seating portion (11 ').

Subsequently, the withdrawal step 116 of the manufactured panel is performed by a conventional in-line mounting method.

FIG. 5 illustrates one of flat panel display panels manufactured by the above-described getter mounting method and mounting structure, in which row lines or data lines 71 and column lines for applying an image data signal are applied. ) 72 are arranged on the vertical axis and the horizontal axis to form the pixel 73 and the getters 60 are mounted on the four exhaust ports 11.

6 shows another example of a flat panel display panel made by the above getter mounting method and getter mounting structure, in which a plurality of getters are mounted in extra areas along the circumference of the screen as the screen size increases. That is, the line lines 71 and the column lines 72 for applying the image data signal are extended one line up, down, left and right alternately around the getter 60 and arranged as shown in the figure. A space for mounting one getter 60 is obtained per side length increase of 1-2 cm. The part where the lines meet each other constitutes the pixel 73.

In this way, as the size of the glass plate 3, 10 increases, the number of getters 60 to be mounted can be increased without limitation.

On the other hand, in order to form a hole in the cathode glass plate 10 for mounting the getter 60, as shown in Fig. 7, first photoresist 80 on the front surface of the 1.5-2.0mm soda lime cathode glass plate 10 Is coated and photolithography forms circular windows 82 in the areas where the vent holes are to be made. At this time, the diameter of the window 82 is formed about 4-6mm depending on the required exhaust conductance (conductance).

Then, the photoresist 80 is coated on the backside of the cathode glass plate 10 and windows 83 for getter mounting are formed on the same axis as the window 82 for the exhaust hole. The diameters of the windows 82 and 83 range from 5 mm to 20 mm depending on the diameter of the circular getter to be mounted, but are not limited thereto. Subsequently, the HF or BHF (buffered HF) etching solution is used to etch through portions of the windows 82 and 83 formed on both sides of the soda lime cathode glass plate 10. The thickness to be etched is about 1.0 to 1.5 mm depending on the thickness of the getter and the thickness of the glass. That is, the exhaust port 11 is sufficiently etched so that the exhaust port 11 is formed in the center of the getter seating portion 11 ′ into which the getter is inserted.

like this " Exhaust port 11 having a getter seat 11 'of the type is a sand-blaster, a drilling method, a laser beam, and the like, in addition to the above photolithography. You can also make

The glass plate thus formed forms the necessary electrodes on the front surface of the glass plate in a typical manner. Finally, by applying a frit paste adhesive along the periphery of the getter seat formed on the rear surface of the glass plate and plasticizing, the sealant on which the getter is mounted is mounted in the mounting chamber, as described above.

As described above, according to the getter mounting method and mounting structure for a flat panel display of the present invention, the getter mounting portion formed on the cathode glass plate does not disturb the display area because the getter is inserted into the getter mounting portion formed on the bottom surface of the cathode glass plate. Any size getter can be mounted and the display panel can be made very thin because the getter is fully inserted into the getter seat and finally mounted by a thin, flat seal.

In addition, since the getter is activated by a getter heater separately installed in the vacuum chamber, the activation temperature can be arbitrarily increased without affecting the glass plate, and impurities that are outgassed when the getter is activated are exhausted before mounting the sealant. It also has the advantage of obtaining activation conditions.

As the size of the panel increases, a plurality of exhaust ports or getters can be effectively installed by arranging the lines of the electrodes in a variable spaced manner as shown in FIG. 6. In this way, by installing several exhaust ports or getters along the edge of the panel, it is possible not only to obtain a proper gettering effect even for a large panel area, but also by outgassing generated during firing of the frit adhesive as in the case of PDP. It is very effective in reducing the problem of contamination around the inner edge.

Previously, in relation to the vacuum in-line mounting technology, the frit glass is calcined with two glass plates separated by a sufficient distance in the vacuum chamber, and the glass plates are combined after the outgassed impurities are completely pumped to recover the vacuum degree. merging) minimizes contamination of the panel inside with outgassing during plasticization.

Claims (10)

delete delete In a getter mounting structure for vacuum in-line mounting a flat panel display, A getter seating portion 11 'formed as a groove in a lower portion of the at least one side exhaust port 11 of the cathode glass plate 10; A lower support plate 30 having a distribution hole 32 formed at a position facing the getter seating portion 11 ′; A sealant (50) for sealing the getter seating portion (11 '); A getter mounting structure for flat panel display vacuum in-line mounting comprising a getter (60) having a size mounted on the sealant (50) and inserted into a getter seating portion (11 '). 4. The getter seating portion (11 ') in communication with the exhaust vent (11) according to claim 3 is " Getter mounting structure for flat panel display vacuum in-line mounting, characterized in that it has a cross section. The getter mounting structure for flat panel display vacuum mounting according to claim 3 or 4, wherein the getter (60) is a circular annular shape or a disc shape. In a getter mounting method for vacuum in-line mounting of a flat panel display, Applying a frit adhesive (12) around the getter seating portion (11 ') formed in the groove of a size larger than the exhaust port (11) in the lower portion of the at least one exhaust port (11) of the cathode glass plate (10); Moving a getter (60) having a size that fits within the getter seat (11 ') below the getter seat (11'); Heating and activating the getter 60 by lowering the temperature of the getter heater 40 without being limited by the application limit temperature of the frit adhesive 12 and other elements by the getter heater 40; A getter mounting method for a flat panel display vacuum in-line mounting comprising the step of mounting a getter (60) in a getter seat (11 '). In a getter mounting method for vacuum in-line mounting of a flat panel display, Applying a frit adhesive (12) around the getter seating portion (11 ') formed in the groove of a size larger than the exhaust port (11) in the lower portion of the at least one exhaust port (11) of the cathode glass plate (10); Mounting a sealant (50) on a getter heater (40) of a size that is capable of covering around the getter seat (11 '); Mounting a getter 60 of a size that fits within the getter seat 11 'on the seal 50; Heating and activating the getter 60 by the getter heater 40 and lowering the temperature of the getter heater 40; Exhausting the interior of the panel and chamber and simultaneously heating the lower support plate 30 to a predetermined temperature to compress the sealant 50 to the frit adhesive 12 together with the getter 60 in the getter seat 11 '. Getter mounting method for configured flat panel display vacuum in-line mounting. 8. The getter seating portion 11 ′ according to claim 7, wherein the exhaust port 11 and the lower getter seat 11 ′ communicate with it. A getter mounting method for flat panel display vacuum in-line mounting, characterized in that formed in the shape of a cross section. delete In the cathode exhaust port forming method of the cathode glass plate used for a flat panel display, Coating a photoresist on the front surface of the cathode glass plate 10 and forming circular windows 82 for the exhaust port 11 by photolithography; Coating photoresist on the back surface of the cathode glass plate 10 and forming the windows 83 for the getter seat 11 'on the same axis as the windows 82 for the exhaust port 11 by photolithography; ; A cathode glass plate for use in a flat panel display, comprising etching the exhaust port 11 and the getter seat 11 'windows 82 and 83 of the cathode glass plate 10 using an HF or BHF etching solution. Method for forming a cathode exhaust port.