JP2001110313A - Baking treatment apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a baking treatment apparatus that can cope with scale enlargement, quality improvement and expanding production of PDP in fabrication of a back plate and a front plate for PDP. SOLUTION: This is a batch-type baking treatment apparatus that conducts baking treatment to bake raw materials for fabricating processing substrate at once for a plurality of processing substrates in a single furnace. It is equipped with many stages of air dispersing plates, that have air-feed holes that supply heating or cooling air on the surface of processing substrates, with prescribed separation nearly at a level. Each processing substrate is mounted on the air dispersing plate described above and is subjected to heating or cooling treatment by blowing heating or cooling air from the dispersing plate onto the processing substrate. Further, heating and cooling portions that control heating and cooling of the fed air, respectively, are equipped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a baking apparatus for baking a processing material, and more particularly, to a baking apparatus for processing a substrate for a plasma display.

[0002]

2. Description of the Related Art In recent years, plasma display panels (hereinafter, also referred to as PDPs) have been used in various display devices because of their small depth, light weight, clear display, and wide viewing angle compared to liquid crystal panels. It is being used.
Generally, a plasma display panel (PDP) has two
A pair of regularly arranged electrodes are provided on a pair of opposed glass substrates, and a gas mainly containing neon, xenon, or the like is sealed between the pair of electrodes. Then, a voltage is applied between these electrodes, and a discharge is generated in minute cells around the electrodes, so that each cell emits light and display is performed. In particular, in order to display information, regularly arranged cells are selectively discharged to emit light.

Here, the structure of the PDP is shown in FIG.
An example of the type PDP will be described. FIG. 5 is a perspective view of the PDP structure, but shows the front plate (glass substrate 410) and the rear plate (glass substrate 420) apart from the actual case for easy understanding. As shown in FIG. 5, two glass substrates 410 and 420 are disposed in parallel and opposed to each other, and both are barriers (cell barriers) provided in parallel on a glass substrate 420 serving as a back plate. 430)
Are held at regular intervals. On the back side of the glass substrate 410 serving as the front plate, composite electrodes composed of a transparent electrode 440 serving as a discharge sustaining electrode and a metal electrode 450 serving as a bus electrode are formed in parallel with each other.
A dielectric layer 460 is formed, and a protective layer (MgO layer) 470 is further formed thereon. In addition, on the front side of the glass substrate 420 serving as a back plate, an address electrode 480 is positioned between the barriers 430 so as to be orthogonal to the composite electrode.
Are formed in parallel with each other, and a fluorescent surface 490 is provided so as to cover the wall surface of the barrier 430 and the cell bottom surface. The barrier 430 divides the discharge space, and each of the divided discharge spaces is called a cell or a unit light emitting region.
This AC type PDP is a surface discharge type, and has a structure in which an AC voltage is applied between composite electrodes on the front panel to cause discharge. In this case, since the alternating current is applied, the direction of the electric field changes according to the frequency. Then, the fluorescent material 490 is caused to emit light by the ultraviolet light generated by the discharge, and the light transmitted through the front plate can be visually recognized by an observer. In addition, DC type PDP
In the above, the electrode is different from the AC type in that the electrode has a structure not coated with the dielectric layer, but the discharge effect is the same. 5 has a structure in which an underlayer 467 is provided on one surface of a glass substrate 420 and a dielectric layer 465 is provided thereon, but the underlayer 467 and the dielectric layer 465 are provided.
Is not necessarily required.

An AC type plasma display (PDP) has been manufactured, for example, as shown in FIG. FIG. 4 shows an AC type PDP manufacturing process, in which a back plate and a front plate are manufactured in separate steps, respectively, and a PDP is assembled using both. First,
The manufacturing process of the back plate will be described. Note that S31 to S54 represent processing steps. First, prepare a glass substrate (S
31) An electrode wiring paste is applied on one side of a glass substrate, dried, processed into a predetermined shape through a plate making process, or the electrode wiring paste is formed on a glass substrate by a thick film printing method. Then, it is baked to form an electrode wiring. (S32) Next, a dielectric layer is formed on the entire surface of the formed electrode so as to cover the glass substrate surface. (S33) Next, a barrier (also referred to as a barrier rib) is formed on the dielectric layer of the glass substrate by a printing method or a sandblast method. (S34) In the case of a printing method, a barrier (barrier rib) forming paste is printed in a predetermined pattern on a glass substrate by a thick film printing method,
This is dried. The thickness of the barrier is large (for example, 100 to 2).
(Thickness of 00 μm) Since this film thickness cannot be obtained by one thick film printing, printing and drying of the barrier forming paste are performed a plurality of times. After a predetermined film thickness is obtained, the paste is fired. In the case of the sand blast method, a barrier forming material is applied on a glass substrate, and after forming a predetermined resist pattern thereon, abrasive sand is sprayed to process the barrier forming material into a shape corresponding to the resist pattern. This is fired to form a barrier. Further, a paste for a phosphor (for example, a paste for a phosphor containing indium oxide) is printed in a predetermined pattern on the substrate on which the barrier is formed by a thick film printing method, and then dried and fired (S35). Form a faceplate. (S36)

Next, a process for manufacturing the front plate will be described. First, a glass substrate is prepared (S41), and a deposition layer of, for example, ITO (Indium Tin Oxide) is patterned on the glass substrate. (S42) The patterning is performed by a normal photolithography process (lithography technology). Next, three layers of Cr-Cu-Cr (chromium, copper, chromium) are formed by vapor deposition or sputtering, and a photolithography process (lithography technology) is performed similarly.
To form an electrode wiring for discharge together with the patterned ITO film. (S43) Next, a transparent dielectric layer is formed by solid printing of the paste-like low melting point glass (S44), and the front plate is obtained. (S45)

Next, a PDP is manufactured using the back plate and the front plate thus obtained as follows. First, the front plate and the back plate are aligned, and in that state, lead glass for sealing is applied to the edges of both substrates, and then sealing is performed. (S51) Next, after the inside of the space surrounded by both substrates (the back plate and the front plate) and the seal portion is evacuated through the exhaust pipe, the discharge gas is sealed in the above-mentioned gap via the exhaust pipe. . (S52) Thereafter, the exhaust pipe is burned off (chip off), and a driver IC is mounted (S53), and a PDP (plasma display panel) is obtained. (S54) As described above, the back plate and the front plate used for the production of the PDP are formed with an electrode wiring portion, a barrier portion, a phosphor portion, a dielectric layer portion and the like through various processes. In addition, it becomes a PDP.

In the production of such a PDP, formation of an electrode wiring portion, formation of a barrier, and the like have recently been performed by sandblasting in terms of productivity, quality, and the like. In this sandblasting process, a processing material composed of a low-melting glass paste for forming an electrode wiring portion and a barrier is applied onto a glass substrate, respectively, and a predetermined resist pattern is formed thereon. Processing the barrier forming material into a shape corresponding to the spray resist pattern,
This is fired to form an electrode wiring portion and a barrier, respectively. However, as the glass substrate, an annealed substrate is used, and each process is performed. Since such a baking process is performed a plurality of times, the management of expansion and contraction of the glass substrate itself is also performed in each process. Required.
For this reason, the baking treatment referred to here is a process of baking the working material after forming a working material made of these low-melting glass pastes on a glass substrate, as shown in FIG. After holding at a temperature Tk for a predetermined time, the glass substrate is gradually cooled to a strain point Ts,
Further, the glass substrate is cooled to room temperature, thereby controlling the expansion and contraction of the glass substrate itself in each process. FIG.
In the graph, T0 indicates normal temperature. In addition, the annealing step
Briefly, it is a process for removing permanent distortion of the glass substrate.
The strain point of the glass substrate is a temperature at which there is no possibility of newly generating permanent distortion due to the rapid cooling, no matter how rapidly the glass substrate is cooled from this temperature. When the temperature is rapidly cooled from the strain point (temperature) to normal temperature, the glass substrate shrinks even during this time, but if the quenching rate is kept constant, the shrinking value can be fixed. That is, the amount of expansion and contraction can be controlled by the value of the cooling rate from the peak temperature to the strain point. In addition, the peak temperature in the firing step is usually a temperature for sintering the working material, and is maintained at this peak temperature for a predetermined time. Usually, the conductive paste for forming the electrode wiring is made of metal fine particles (for example, Ag), a low-melting glass frit, a resin, and a solvent, and the paste for forming the dielectric layer is made of the low-melting glass frit, a resin, and a solvent. And fillers, pigments and the like are added as necessary. The paste for forming the barrier is made of a low-melting glass frit, a filler (alumina, zirconia, etc.), a pigment, a resin, and a solvent. These pastes are generally referred to as low-melting glass or low-melting glass paste because they contain, as a main component, a low-melting glass frit for flowing and fixing in a firing process.

A conventional baking apparatus for producing a back plate and a front plate for a PDP includes a heating process while transferring a processing substrate into a long furnace capable of obtaining a desired baking profile and performing a continuous process. A continuous firing furnace (not shown) for performing a cooling process (also referred to as a roller hearth type) has been used. However, this type of sintering processing apparatus has an essential problem that the installation space is large, and it is difficult to clean the furnace for transport and the inside of the furnace. In the production, it could not be said that it was a firing treatment apparatus that could respond to the increase in size, quality, and mass production of PDPs.

[0009]

Under these circumstances, in recent years, PDPs have been required to be large-sized, high-quality, and mass-produced. There has been an increasing demand for a sintering processing apparatus that can satisfy the quality requirements. The present invention has been made to address this, and it is an object of the present invention to provide a baking treatment apparatus capable of coping with an increase in the size, quality, and mass production of a PDP in manufacturing a back plate and a front plate for a PDP.

[0010]

SUMMARY OF THE INVENTION A baking treatment apparatus according to the present invention is a batch-type baking apparatus for baking a processing material of a processing substrate in a single furnace for a plurality of processing substrates at once. A sintering processing apparatus, in which air dispersion plates provided with air supply holes for supplying heating air or cooling air to the processing substrate surface are provided at a predetermined interval substantially horizontally and in multiple stages, and each processing is performed. A substrate is mounted on the air dispersion plate, and air for heating or air for cooling is blown from the air dispersion plate to the processing substrate to perform a heating process or a cooling process. . In the above, a heating unit that controls and heats the supplied air and a cooling unit that controls and cools the air are provided. Further, in the above, a heater for heating is provided on a wall portion in the furnace. In the above, the processing substrate is a back plate for a plasma display, and the processing material is a material for forming a barrier, a material for forming an electrode, or a material for forming a phosphor.

[0011]

The firing apparatus of the present invention having such a structure makes it possible to provide a batch-type firing apparatus capable of coping with a firing step in the production of a back panel and a front panel for a PDP. That is, a desired temperature profile can be obtained, and the installation space is small and the cleanliness is easy, as compared with the conventional continuous firing furnace (also referred to as a roller hearth type). ,
It is said that it can respond to mass production. Specifically, a batch-type baking treatment apparatus for performing a baking treatment for baking a processing material of a processing substrate on a plurality of processing substrates at one time in one furnace, and using heating air or An air distribution plate provided with an air supply hole for supplying cooling air to the processing substrate surface is provided in multiple stages at predetermined intervals substantially horizontally, and each processing substrate is mounted on the air distribution plate, Heating or cooling processing is performed by blowing heating air or cooling air from the air dispersion plate onto the processing substrate to perform heating processing or cooling processing. This is achieved by providing a cooling unit that cools down. In other words, air for heating or air for cooling is blown from the air dispersion plate to the surface of the substrate to be processed, so that the material for processing the substrate to be processed can be heated or cooled with good temperature controllability. Fig. 3
It is possible to take a desired firing temperature profile as shown in FIG.

Further, the provision of the heater for heating on the wall in the furnace makes it possible to heat the processing substrate accurately in a short time.

It is particularly effective when the processing substrate is a back plate for a plasma display and the processing material is a material for forming a barrier, a material for forming an electrode, or a material for forming a phosphor.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One example of an embodiment of a baking treatment apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of an example of an embodiment of a baking treatment apparatus according to the present invention, and FIG. 2A is a view of an air dispersion plate viewed from a processing substrate mounting side.
(B) is a part of the A1-A2 cross section of FIG. 2 (a). 1 and 2, 110 is a baking furnace, 120 is an air dispersion plate,
121 is a glass part, 125 is a hole (for blowing out), 1
26 is a hole (for air supply), 130 is a processing substrate, 1
40 is an air supply unit, 140A is supply air, 141
Is an air supply port, 145 is an air discharge section, 145A is discharge air, 146 is an air discharge port, 150 is a heating section,
155 is heating air, 160 is a cooling unit, 165 is cooling air, 170 is an air supply path, 171 to 174 are valves, 1
80 is a blower and 190 is a heater. One example of the embodiment shown in FIG. 1 is a process used for forming an electrode wiring (corresponding to S32 in FIG. 3) and forming a barrier (corresponding to S33 in FIG. 3) in manufacturing a back plate for a plasma display panel. A baking process for baking a processing material of the processing substrate 130 is performed by a baking processing apparatus used for a baking process of a processing material (paste) in a single furnace.
This is a batch-type baking treatment apparatus for performing the same at once. An air distribution plate 120 provided with air supply holes 125 and 126 for supplying heating air or cooling air to the surface of the processing substrate is provided substantially horizontally and in multiple stages at predetermined intervals. 130 is mounted on the air dispersion plate 120, and heating or cooling air is blown from the air dispersion plate 120 to the processing substrate 130 to perform a heating process or a cooling process.

In this embodiment, the air dispersion plate 120 is made of a heat-resistant glass substrate, on which the processing substrate 130 is placed, and as shown in FIG.
Holes 12 for blowing air from the air through holes 126
5 is supplied. The blowing holes 125 are provided on the side of the processing substrate 130 to be mounted, that is, on the upper side, and a part of the cross section along A1-A2 is as shown in FIG. 2B. The glass part 121A and the glass part 121B have a structure in which separate parts are overlapped. While the air for heating or cooling is being blown out from the hole 125 for blowing out, the substrate 130 may be pushed and floated by the air from the lower side thereof. A position fixing portion for preventing a large displacement is provided at a predetermined position on the upper surface of the air distribution plate 120.

The air supply section 140 is provided at each air supply port 1.
A part for supplying air for heating or cooling to 41,
The heating unit 155 and / or the cooling unit 160 receive the heating air 155, the cooling air 165, or the mixed air of the heating air 155 and the cooling air 165. The heating unit 150 opens the valves 171 and 172,
The air from the blower 180 is heated and heated air 15
5 is supplied to the air supply unit 140, and a heater is provided around the air supply path 170 to heat the air. still,
Reference numerals 161 and 162 denote cooling water, and arrows indicate the flowing directions. The cooling unit 160 cools the air from the blower 180 by opening the valves 173 and 174, and supplies the cooling air 165 to the air supply unit 140. To cool down. Of course, if necessary, the heating air 155 and the cooling air 165 are used in a mixed state. Although not shown, the air to be supplied into the firing furnace can be supplied with clean air by passing through a HEPA filter immediately after the blower 180.

In the present embodiment, a heater 190 is provided over the entire inner surface of the furnace wall 111 in order to facilitate heating of the processing substrate 130. Although not shown in detail, the heater 190 is of a type that sends heat from a heat source to the processing substrate 130 by blowing air.

The wall 111, the air supply section 140, the respective air supply ports 141, the air discharge section 145, the air discharge port 146, and the air supply path 170 may be formed of a commonly used heat insulating material. Applicable.

Although not shown, a temperature sensor is provided in each section, and the valves 171 and 172 of the heating section 150 and the cooling section 16 are provided based on information from the temperature sensor.
A mechanism for controlling the zero valves 173 and 174, the blower 180, and the heater 190 is provided.

Here, an example of the schematic operation of the baking apparatus will be described with reference to FIG. FIG. 3 is a schematic view showing a profile of the relationship between the temperature and time of the target glass substrate in the firing step, and the firing process is performed in this manner. In FIG. 3, T0 is a temperature before and after firing, Tk is a keep temperature, Ts is a strain point (temperature), 310 is a temperature raising process, 320 is a temperature holding process, 330 is a slow cooling process, and 340 is a rapid cooling process. First, the heating air 155 is supplied to the air supply unit 140.
The temperature increase process 310 is performed in a state in which only the heater 190 is supplied and the heater 190 is turned on. Next, the air supply unit 1
40, the heating air 155 and the cooling air 165 are mixed and supplied, and the heater 190 is heated 3
The temperature holding process 320 is performed in a state where the heating effect is weaker than 10. Next, the heating effect is weakened as compared with the temperature holding process 320, and the heated air 1 is supplied to the air supply unit 140.
55 and the cooling air 165 are mixed and supplied.
In addition, the slow cooling process 330 is performed while the heating effect of the heater 190 is weaker than that of the temperature holding process 320. Next, in a state where only the cooling air 165 is supplied to the air supply unit 140 and in a state where the heater 190 is not attached,
A quenching process 340 is performed.

Briefly, as described above, each part is operated to perform each processing and control the temperature of the processing substrate 130. In each processing, the supply amount of air and the heating air 15 are controlled.
The degree of mixing of the cooling air 165 and the cooling air 165 and the degree of heating of the heater 190 are precisely adjusted by automatically arranging a temperature sensor based on information from each sensor. Can be obtained. For example, in advance, conditions for obtaining a target profile using a test substrate are grasped, and when processing the processing substrate 130 based on these conditions as basic conditions,
Processing conditions may be further determined based on information from each temperature sensor.

Here, the temperature T0 before and after the firing is defined as
At a constant temperature of about 22 ° C., this is also referred to as room temperature. The keep temperature Tk is a temperature for firing the paste to be used, and is also a peak temperature in the firing step. As described above, the strain point (temperature) Ts is a temperature at which there is no possibility of causing any new permanent deformation due to the rapid cooling, no matter how rapid cooling is performed from this temperature. That is,
Even if the temperature is rapidly cooled from the strain point (temperature) Ts to room temperature, the expansion and contraction of the glass substrate can be almost ignored. Slow cooling is a cooling method that gradually (usually takes 2 hours or more) from the keep temperature Tk to the strain point (temperature) Ts. The magnitude of the slow cooling rate affects the expansion and contraction of the glass substrate. Also,
Generally, an operation of heating the glass substrate again after forming, raising the temperature to near the softening point, and then cooling sufficiently slowly is referred to as annealing treatment (annealin). Then, the upper limit of the annealing temperature (also referred to as annealing temperature) is referred to as annealing point. In general, the definition of Littleton as the temperature at which the strain disappears in 15 minutes is widely used.

[0023]

According to the present invention, as described above, the firing process for firing the processing material of the processing substrate is performed in one furnace.
A batch-type baking processing apparatus for performing a batch process on a plurality of processing substrates at once, and performs baking processes such as plate making for forming electrode wiring on a glass substrate for plasma display and plate making for forming a barrier. It is possible to provide a product that can be performed with a predetermined temperature profile. As a result, compared to a conventional continuous firing furnace (also referred to as a roller hearth type) in which a processing substrate is transferred while being transported into a long furnace.
Installation space can be reduced, cleanliness is easy, and
In manufacturing back and front plates for PDPs, it has become possible to provide a baking treatment apparatus that can respond to the increase in size, quality, and mass production of PDPs.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an example of an embodiment of a baking treatment apparatus of the present invention.

FIG. 2A is a diagram of the air dispersion plate viewed from a processing substrate mounting side, and FIG. 2B is a diagram illustrating a part of a cross section taken along line A1-A2 of FIG. 2A.

FIG. 3 is a diagram showing a temperature profile of a baking process;

FIG. 4 is a process chart for explaining a PDP manufacturing process.

FIG. 5 is a diagram illustrating a PDP substrate.

[Explanation of symbols]

 110 firing furnace 120 air dispersion plate 121 glass part 125 hole part (for blowing out) 126 hole part (for air supply) 130 processing substrate 140 air supply part 140A supply air 141 air supply port 145 air discharge part 145A discharge air 146 Air outlet 150 Heating section 155 Heating air 160 Cooling section 165 Cooling air 170 Air supply path 171 to 174 Valve 180 Blower 190 Heater 310 Heat-up processing 320 Temperature holding processing 330 Slow cooling processing 340 Rapid cooling processing T0 Temperature before and after firing Tk Keep Temperature Ts Strain point (temperature)

Claims (4)

[Claims] 1. A batch type baking apparatus for performing a baking process for baking a processing material of a processing substrate on a plurality of processing substrates at once in a single furnace. An air distribution plate provided with an air supply hole for supplying cooling air to the processing substrate surface is provided in multiple stages at predetermined intervals substantially horizontally, and each processing substrate is mounted on the air distribution plate, Air for heating or air for cooling is blown from the air dispersion plate to the processing substrate,
A baking treatment apparatus for performing a heating treatment or a cooling treatment. 2. The baking treatment apparatus according to claim 1, further comprising a heating unit for controlling and heating the supplied air, and a cooling unit for controlling and cooling. 3. The baking treatment apparatus according to claim 1, wherein a heater for heating is provided on a wall in the furnace. 4. The method according to claim 1, wherein the processing substrate is a back plate for a plasma display, and the processing material is a barrier forming material, an electrode forming material, or a phosphor forming material. Baking treatment device.