JP3607443B2 - Substrate baking apparatus including film forming material - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a baking apparatus for uniformly performing a heat treatment on a substrate including a film forming material.
[0002]
[Prior art]
On a glass substrate typified by soda lime glass or a ceramic substrate typified by alumina, a metal or inorganic material is melted with a glass bond component, or the material itself is softened, melted, or sintered to have a predetermined function. A substrate containing a film-forming material, on which the resulting film is fixed, is known. For example, an anode substrate for a fluorescent display tube, a substrate for a plasma display panel, a plasma switching substrate for a plasma addressed liquid crystal display device, a display device substrate such as a field emission display device substrate, a thick film wiring substrate, a thermal printer head, or an image sensor It is a substrate for electronic devices such as. Such a substrate for an electronic device is generally subjected to a heat treatment of about 500 to 650 (° C.) for annealing the substrate itself or for forming a functional material film using a glass material as a binder. The substrate is subjected to a heat treatment of, for example, about 500 to 900 (° C.) in order to form a functional material film using a glass material as a binder, or to form a functional material film using melting at the interface of the metal material itself. .
[0003]
[Problems to be solved by the invention]
By the way, in recent years, a substrate including the film forming material has been designed to be multi-layered and densified such as conductors, resistors, and dielectrics formed by patterning on the surface thereof. With the increase in size, it is necessary to manufacture a relatively large size. For this reason, the display device substrate is required to form a fine pattern over a large size, and the electronic device substrate is provided with a high quality by miniaturizing the pattern space given to the function generating film. Therefore, the uniformity of the film is further required. However, the quality impact caused by the firing of the substrate increases as the size increases as described above, and the variation thereof becomes a constraint in product design, and is one factor that reduces the product yield. It was.
[0004]
For example, when there is a dimensional variation due to expansion or contraction of the substrate material itself with the heat treatment, it is difficult to align the patterns for each baking performed after patterning of the functional film. In addition, the resistance layer has a variation in resistance value, the dielectric layer has a variation in withstand voltage, and a variation in thickness due to non-uniformity of the residual ratio, and the conductor layer has a large variation in conduction resistance, wire bonding property, sputtering property, etc. Become. The consistency of alignment between these patterns and the uniformity of layer quality are more difficult to maintain as the pattern becomes finer or the substrate becomes larger, resulting in an inconvenience that the product yield decreases at an accelerated rate. It was. Therefore, for example, taking a plasma display substrate as a large display device of 40 inches or more as an example, there are the following yield reduction factors. In other words, the dimensional accuracy of each layer of the multilayer structure forming a large number of cells cannot be ensured, the height and width of the barriers vary, the resistance value varies in the resistance cell, and the dielectric layer has resistance. For example, the voltage varies, and the overall dimensional variation includes a deviation when the discharge cells are formed by combining the front plate and the rear plate.
[0005]
The present invention has been made against the background of the above circumstances, and its object is to sinter a substrate containing a film-forming material that can increase the yield of the substrate containing the film-forming material by uniform heating in the substrate. Is to provide.
[0006]
As a result of various studies to achieve the above-mentioned problems, the inventor has found that the metal contained in the thick film, the molten or sintered state of the inorganic material, the glass bond component that is lowered to fix the functional component, or It has been found that in the dielectric, the softening or melting state of the glass component itself is locally different within the substrate. The present invention has been made based on the above findings.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the gist of the present invention is that each of the plurality of substrates in the process of sequentially transporting the plurality of substrates including the film forming material in one direction. Slow cooling uniformly following heating A tunnel-like firing device for performing a treatment, (a) Slow cooling zone following heating zone And a plurality of the first Soaking A temperature control device for controlling soaking for each section, and (b) the plurality of substrates on each of the plurality of substrates. Soaking A transporting device for supporting the plurality of substrates by a plurality of rollers that are driven to rotate about axes that are perpendicular to the longitudinal direction and parallel to each other in order to perform heat treatment in sections; (c) The plurality of rollers between the plurality of rollers Soaking An axis parallel to the axial direction of the plurality of rollers between a shielding angle position that shields the sections from each other and a retraction angle position that avoids interference with the plurality of substrates conveyed by the conveying device And a shutter device provided with a flat plate-like rotary shutter that can be rotated around.
[0008]
【The invention's effect】
In this way, the tunnel-like firing device is Slow cooling zone A plurality of substrates arranged along one direction, which is the substrate transport direction Soaking A temperature control device that controls soaking for each section, a transport device that supports a plurality of substrates by a plurality of rollers that are driven to rotate around an axis perpendicular to the longitudinal direction and parallel to each other, and transports the substrate in one direction; Multiple between rollers Soaking A plate-like rotary shutter that is rotated around an axis parallel to the axial direction of the roller between a shielding angle position that shields the sections from each other and a retraction angle position that avoids interference with the substrate being conveyed. And a shutter device provided. Therefore, the substrate including the film forming material is a plurality of processes in the process of being transported along one direction by the transport device in the cooling process of heat treatment. Soaking Placed sequentially into the sections, where each is soaked Slowly cooled The At this time, multiple Soaking The sections are shielded from each other by the shutter device when the rotating shutter is positioned at the shielding angle position, and each is thermally independent. Soaking The soaking state in the section is preferably realized, but when the substrate is transported, the rotating shutter is positioned at the retraction angle position, so that interference between the substrate and the rotating shutter is avoided. Transport is not hindered at all. In this way, in the process of being transported in one direction Soaking Since the cooling process of the heat treatment is performed while repeating soaking sequentially for each section, the temperature variation in the substrate including the film forming material is made as small as possible.
[0009]
Therefore, when the substrate is made of glass and is heat-treated at a temperature higher than its strain point, the local change in dimensions within the substrate, that is, the distortion of the formation pattern is reduced as much as possible. Misalignment with subsequent patterns is prevented, and the manufacturing yield is dramatically increased even with fine patterns and large substrates. In addition, since the temperature variation in the substrate including the film forming material is minimized as described above, the thick film dielectric layer, the partition-like dielectric layer, the thick film resistive layer, the electrode are formed on the surface of the substrate. When a layer or an inorganic colored pigment layer is provided, the glass that functions as a bond component in the thick film has a uniform degree of melting and softening, and a metal-metal oxide-based melting and firing. The degree of bonding is uniform, and the withstand voltage quality, partition wall height and width dimensions, resistance values, discharge quality, optical filter characteristics variation, etc. are suitably reduced. Is dramatically improved. Furthermore, as a result of reducing the variation in the resistance value as described above, the process management load and the process such as trimming are reduced or the load is reduced.
[0010]
In addition, the shutter device has a plurality of rotating shutters. Soaking Because it shields each other from each other, Soaking Since there is no sliding portion in the region, problems such as generation of dust accompanying sliding of the shutter and breakage of the sliding portion due to thermal expansion are unlikely to occur. In addition, since the transport device supports a plurality of substrates by a plurality of rollers that are rotationally driven around an axis and transports the substrate in one direction, the transport device is Soaking Control multiple categories Soaking Since it is easy to carry between sections independently, Soaking Compared to the case of simultaneous transport by section Soaking It is possible to increase the processing efficiency of the substrate by shortening the moving time when the substrate is not heat-treated in the section as much as possible. In addition, there is no sliding of the belt that causes dust generation compared to the case of transporting with a mesh belt etc. Soaking The degree of cleanliness in the region is increased, and damage to the function of the film formed in the process of uniformly heat-treating the substrate is suppressed.
[0011]
Other aspects of the invention
Here, it is preferable that the shutter device has the plurality of shutters at positions separated by a predetermined distance or more from the conveyance surfaces of the plurality of substrates formed by the plurality of rollers. Soaking It further includes a fixed shutter that is fixedly provided to shield the sections from each other. In this way, multiple Soaking Between the sections, a range that does not hinder the conveyance at a predetermined distance or more from the conveyance surface of the substrate at the boundary between the sections is always shielded by the fixed shutter. Therefore, the rotating shutter has a remaining portion where the fixed shutter is not provided. The size of shielding is sufficient. Therefore, it is perpendicular to the one direction and the axial direction of the roller. Soaking Even when the height of the area is set sufficiently large with respect to the thickness dimension of the substrate (when the substrate is transported on a setter, the thickness dimension of the entire object to be conveyed including it) Since the roller interval required to rotate the rotating shutter is sufficiently small, Soaking There is no particular hindrance to the conveyance of the substrate at the boundary of the section. In addition, since the movable part of the shutter device becomes small, the rotation drive becomes easy, and it is suppressed that the drive becomes difficult due to thermal deformation of the shutter.
[0012]
Preferably, the transfer device transfers the plurality of substrates to the plurality of substrates. Soaking It is an intermittent conveying apparatus that conveys intermittently for each section. In this way, in the process where the substrate is intermittently transported in one direction, a plurality of Soaking Since the heat treatment is performed sequentially in the sections, the temperature in the substrate during the cooling process of the heat treatment is compared with the case where a continuous heat curve is formed by continuously transporting the substrate including the film forming material. The overall length of the cooling region required for sufficiently reducing the difference is shortened, and the baking apparatus is downsized.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
[0014]
1, 2, and 3 show a configuration of a continuous baking apparatus 116 that performs baking in the process of sequentially transporting the substrate 62 of one embodiment of the present invention in one direction, and FIG. 1 is a front view. 2 is a cross-sectional view along the longitudinal direction passing through the center of the furnace body in the width direction, and FIGS. 3A to 3E are cross-sectional views taken along lines aa to ee in FIG. 2, respectively. In the figure, a first transport device 118, a plurality of second transport devices 120 a, 120 b, to 120 f (hereinafter simply referred to as the second transport device 120 unless otherwise specified) and a third transport device 122 are driven independently. The substrates 62 are arranged in series, and the substrate 62 is transferred in one direction by the first transfer device 118, the second transfer device 120, and the third transfer device 122. When not particularly distinguished, it is simply passed through the furnace body 124).
[0015]
The tunnel-shaped furnace body 124 has an inner wall made of heat resistant glass such as β-spodumene-based crystallized glass. In the furnace body 124a, the substrate 62 is heated to the maximum processing temperature, and in the process, a preheating zone (preheating portion) for removing the binder (resin) contained in the film printed on the substrate 62 by burning is removed. 126, a heating zone (heating unit) 128 for holding the substrate 62 at the maximum processing temperature for a predetermined time, and a slow cooling zone (slow cooling unit) 130 for gradually cooling the substrate 62 are provided. In the furnace body 124b, a cooling zone (cooling part) 132 for cooling the substrate 62 to near room temperature is provided.
[0016]
The first transport device 118 is provided at a position corresponding to the preheating zone 126 and the heating zone 128. The first transport device 118 is configured to rotate a motor 134 with a speed reducer provided below the furnace body 124a and continuously driven, and a chain 136 and a plurality of line shafts 138a and 138b provided on one axis. ˜138e (hereinafter simply referred to as “line shaft 138” unless otherwise specified) Miter gears 140a, 140b, ˜140f provided at predetermined intervals along the longitudinal direction of the furnace body 124a (hereinafter referred to as “not particularly distinguished”) Is simply transmitted to the miter gear 140, and is divided by the miter gear 140, respectively. When not particularly distinguished, it is simply referred to as drive section 129) for each FIG. As shown, by rotating a roller 166 provided in the furnace body 124a, the substrate 62 placed on the roller 166 is continuously transferred at a first transport speed of, for example, about 300 (mm / min). It is to be transported.
[0017]
FIG. 4 is an enlarged view of the main parts of the first transport device 118 and the second transport device 120 arranged vertically with the middle omitted, and the drive sections 127a, 129b, 131b shown in FIG. The parts corresponding to each are shown in the upper, middle, and lower stages, respectively. The miter gear 140 a of the first transport device 118 corresponding to the drive section 127 a has a driving shaft 142 a provided with the axial direction along the longitudinal direction of the furnace body 124, and the axial direction in the longitudinal direction of the furnace body 124. And a driven shaft 144a which is vertical (perpendicular to the paper surface). When the rotation of the motor 134 is transmitted to the miter gear 140a by the chain 136 and the driving shaft 142a is rotated in the direction of the arrow, the line shaft 138a connected to the driving shaft 142a via the coupling 146 is connected to the driving shaft 142a. While being rotated in the same direction, the driven shaft 144a is rotated in the direction of the arrow in the figure, for example.
[0018]
On the other hand, FIG. of The miter gear 140f corresponding to the drive section 129b shown in the middle stage, that is, the miter gear 140f provided at the right end of the first conveying device 118, has one end of the driving shaft 142f connected to the line shaft 138e via the one-way coupling 148. It is connected. Further, a motor 150 with a speed reducer is provided on the other end side of the driving shaft 142 f and is connected to the other end via a one-way coupling 152. These one-way couplings 148 and 152 transmit only the rotation of the line shaft 138e and the motor 150 in the direction of the arrows in the figure to the miter gear 140f, respectively. The motor 150 is synchronized with a second transport device 120 described later. It is intermittently driven at a higher rotational speed than the line shaft 138. Therefore, while the motor 150 is stopped, the rotation of the line shaft 138e is transmitted to the driving shaft 142f via the one-way coupling 148, and the one-way coupling 152 is slid, while the motor 150 is driven via the one-way coupling 152. The rotation is transmitted to the driving shaft 142f, and the one-way coupling 148 is slid. Therefore, during the driving of the motor 150, the substrate 62 on the roller 166 in the drive section 129b is, for example, about 5000 (mm / min) faster than the first transport speed (for example, about 300 [mm / min]). It is transported at the second transport speed. The drive sections 127b, 127c, and 129a that are omitted are connected to the driving shaft 142 of the miter gears 140b, 140c, and 140e via a coupling (not shown) in which the line shafts 138a, 138b, and 138e are the same as the coupling 146. The driven shafts 144 are connected to each other and rotated as the driving shaft 142 rotates.
[0019]
Further, below the plurality of miter gears 140, there are a plurality of rotating shafts 154 arranged along the longitudinal direction in parallel with each other so that the axial direction is perpendicular to the longitudinal direction of the furnace body 124 and the horizontal direction. Is provided. For this reason, the first transport device 118 is provided with a large number of rotating shafts 154 along the longitudinal direction of the furnace body 124 over the entire length thereof. The rotation shaft 154 is rotated in a direction indicated by an arrow in the drawing by transmitting the rotation of the driven shaft 144 by, for example, a chain (or timing belt) 156. For this reason, when the motor 134 is driven, the rotation shafts 154 of the multiple first conveying devices 118 arranged along the longitudinal direction of the furnace body 124 are simultaneously rotated at the same rotation speed and rotation direction. However, when the motor 150 is driven, the rotation is transmitted to the miter gear 140f, the connection of the line shaft 138e is substantially disconnected by the one-way coupling 148, and the rotating shaft 154 provided below the miter gear 140f, That is, the rotating shaft 154 belonging to the drive section 129 b adjacent to the slow cooling zone 130 in the heating zone 128 is faster than the rotating shaft 154 belonging to the other drive sections 127 and 129 a in the first transport device 118. It will be rotated at the same speed.
[0020]
Further, as shown for the drive section 131b in the lower part of FIG. 4, the plurality of second transport apparatuses 120 are motors with speed reducers 158a, 158b, to 158f (hereinafter particularly distinguished from each other) intermittently driven independently. When the motor 158 is not used, it is simply referred to as a motor 158). Like the first transfer device 118, a plurality of rotations provided vertically and horizontally with respect to the longitudinal direction of the furnace body 124 are provided below the motor 158. A shaft 154 is provided. The rotation shaft 154 is rotated in the same direction by transmitting the rotation of the output shaft 160 of the motor 158 through the chain 156. That is, each of the plurality of second transport devices 120 includes a motor 158 that is independently driven in place of the miter gear 140 to which the rotation of the motor 134 is transmitted in the first transport device 118. The motor 158 is not only driven forward in the forward direction indicated by the arrow in the figure, but can also be driven in reverse to alternately rotate in the forward and reverse directions. During driving, the roller 166 connected to the rotating shaft 154 is rotated so as to obtain the second transport speed (for example, about 5000 [mm / min]), while during reverse driving, for example, 1300 (mm / Min), the roller 166 is rotated in the forward rotation direction and the reverse rotation direction so that the substrate 62 is reciprocated in the transfer direction and the opposite direction at a third transfer speed of about / min).
[0021]
As is apparent from FIG. 1, the third transport device 122 is configured such that the number of miter gears 140 is reduced in the first transport device 118 and the longitudinal direction of the furnace body 124 is reversed. That is, the drive section 133a has the same configuration as the drive section 129b, the drive section 133b has the same configuration as the drive section 127b, and the drive section 133c has the same configuration as the drive section 127a. Therefore, the rotation of the motor 162 with a speed reducer provided below the furnace body 124b is transmitted to the miter gears 140i, 140h, and 140g via the chain 163, the line shafts 138g, and 138f, and is provided in each drive section 133. The rotating shaft 154 is rotated. Further, in the drive section 133a adjacent to the slow cooling zone 130, as in the drive section 129b, the rotation of the motor 164 with a speed reducer is transmitted via the one-way coupling, so that the rotation shaft 154 belonging to the motor 164 is intermittently transmitted. Driven at a speed higher than that of the other rotating shaft 154, that is, at a speed synchronized with the second transport device 120.
[0022]
Returning to FIG. 2, a plurality of cylindrical rollers 166 made of alumina, for example, are provided in the furnace body 124, and FIGS. 3 (a) to 3 (e) are cross-sectional views taken along lines aa to ee in FIG. 2. As shown, both end portions are provided so as to protrude from the side surface of the furnace body 124. A pair of bearings 167 and 167 (shown only in FIG. 3 (a)) are provided on the outer sides of the furnace body 124, and the rotating shaft 154 is supported coaxially with the roller 166, respectively. Each of the rollers 166 is provided between the pair of rotating shafts 154 from both sides, and the motor 134 rotates the chain. 156 Is rotated with the rotation of the rotating shaft 154 transmitted through the. Note that FIG. 3A is a diagram corresponding to the section aa in FIG. ₂ -A ₂ The visual cross section has the same cross sectional shape. The substrate 62 is supported by the roller 166 in the furnace body 124. Therefore, if the roller 166 is rotated, it will be conveyed in one direction with the rotation. At this time, the roller 166 is continuously rotated in the preheating zone 126, the heating zone 128, and the cooling zone 132 in which the first transport device 118 and the third transport device 122 are provided, so that the substrate 62 is transported continuously. On the other hand, in the slow cooling zone 130 in which the second transport device 120 is provided, the roller 166 is intermittently rotated to transport the substrate 62 intermittently. That is, in the present embodiment, the first transport device 118 and the third transport device 122 correspond to a continuous transport device, and the second transport device 120 corresponds to an intermittent transport device, that is, a “transport device” in the claims.
[0023]
1, 2, and 3, the preheating zone 126 includes a plurality of temperature detectors TC for detecting the temperature in the preheating zone 126 for each drive section 127. A heater H that is provided vertically at three positions in the width direction at the center in the longitudinal direction and that forms a plurality of zones on the upper and lower sides of the furnace body 124 and is independently controlled for each zone is provided for each drive section. Four zones are provided for each 127 in the longitudinal direction and the width direction of the furnace body 124. That is, although a part is omitted in FIGS. 1 to 3, as schematically shown for the drive section 127a in FIG. 5 (a), the feed direction A of the substrate 62 is orthogonal to each drive section 127 and orthogonal thereto. A total of 16 sets of heaters H divided into four in the longitudinal direction of a roller 166 (not shown). ₁₁₁₁ , H ₁₁₁₂ , H ₁₁₁₃ , H ₁₁₁₄ , H ₁₁₂₁ , H ₁₁₂₂ , H ₁₁₂₃ , H ₁₁₂₄ , H ₁₁₃₁ , H ₁₁₃₂ , H ₁₁₃₃ , H ₁₁₃₄ , H ₁₁₄₁ , H ₁₁₄₂ , H ₁₁₄₃ , H ₁₁₄₄ (The driving sections 127b, 127c, and 127d have H ₁₂₁₁ ~ H ₁₂₄₄ , H ₁₃₁₁ ~ H ₁₃₄₄ , H ₁₄₁₁ ~ H ₁₄₄₄ Are provided as a pair above and below the furnace body 124, and the heater H ₁₁₂₁ And H ₁₁₃₁ Between the heater H ₁₁₂₂ , H ₁₁₂₃ , H ₁₁₃₂ And H ₁₁₃₃ Between the heater H ₁₁₂₄ And H ₁₁₃₄ Temperature sensor TC at a position between ₁₁₁ , TC ₁₁₂ , TC ₁₁₃ (The drive sections 127b, 127c, and 127d have TCs respectively. ₁₂₁ ~ TC ₁₂₃ , TC ₁₃₁ ~ TC ₁₃₃ , TC ₁₄₁ ~ TC ₁₄₃ ) Is arranged. As illustrated in part of the upper side of the drive section 127a in FIG. 2, each temperature detector TC and the heater H are connected to the control device 168, and the heater H's according to the temperature signal detected by the temperature detector TC. The output is controlled.
[0024]
Further, in the preheating zone 126, an air supply pipe 170 is provided in the upper part of the inlet of the drive section 127a on the inlet side of the furnace body 124, and an exhaust pipe 172 on the front side in the transport direction of the substrate 62 of the subsequent drive sections 127b, 127c, 127d. Is provided. The air supply pipe 170 and the exhaust pipe 172 are made of, for example, the same alumina ceramics as the roller 166 and are provided so as to penetrate in the width direction of the furnace body 124. The supply pipe 170 is connected to the supply pipe 174 provided on the side of the furnace body 124 at both ends thereof, and supplies air guided from an air supply source (not shown) into the furnace body 124. In addition, the exhaust pipe 172 is connected to exhaust pipes 176 provided on the side surfaces of the furnace body 124 at both ends thereof, and a plurality of exhaust pipes are supplied in the process in which the air supplied into the furnace body 124 flows through the exhaust pipe 172. The air is sucked in from 172 and discharged from the discharge port 178. Each of the supply pipe 170 and the exhaust pipe 172 is provided with a round hole-shaped nozzle 171 or a long hole-shaped nozzle 181 at a plurality of positions as shown in FIGS. 6 (a) and 6 (b).
[0025]
Further, in the heating zone 128, a plurality of temperature detectors TC for detecting the temperature in the heating zone 128 are provided above and below at three positions in the longitudinal direction and the width direction of the furnace body 124 for each drive section 129. In addition, a heater H that forms a plurality of zones on the upper side, the lower side, and the upper part of both side surfaces of the furnace body 124 and is controlled independently for each zone is provided in the longitudinal direction of the furnace body 124 for each drive section 129. 4 zones, and 6 zones each including 1 zone at the top of both sides in the width direction are provided. That is, as shown in FIG. 5B, for each drive section 129, a total of 16 sets of heaters H divided into four in the feed direction A of the substrate 62 and in the longitudinal direction of the roller 166 (not shown) orthogonal thereto. ₂₁₁₁ , H ₂₁₁₂ , H ₂₁₁₃ , H ₂₁₁₄ , H ₂₁₂₁ , H ₂₁₂₂ , H ₂₁₂₃ , H ₂₁₂₄ , H ₂₁₃₁ , H ₂₁₃₂ , H ₂₁₃₃ , H ₂₁₃₄ , H ₂₁₄₁ , H ₂₁₄₂ , H ₂₁₄₃ , H ₂₁₄₄ Are arranged as a pair on the upper and lower sides of the furnace body 124, and the heater H is divided into four (four sets) in the feed direction A on the upper side surfaces on both sides in the width direction of the furnace body 124. ₂₁₁₅ , H ₂₁₂₅ , H ₂₁₃₅ , H ₂₁₄₅ , H ₂₁₁₆ , H ₂₁₂₆ , H ₂₁₃₆ , H ₂₁₄₆ (H in the drive section 129b ₂₂₁₁ ~ H ₂₂₄₆ ) Are arranged as a pair on both side surfaces. Heater H ₂₁₁₁ H ₂₁₁₂ And H ₂₁₁₃ H ₂₁₁₄ H ₂₁₂₁ And H ₂₁₃₁ H ₂₁₂₂ , H ₂₁₂₃ , H ₂₁₃₂ , H ₂₁₃₃ H ₂₁₂₄ And H ₂₁₃₄ H ₂₁₄₁ H ₂₁₄₂ And H ₂₁₄₃ H ₂₁₄₄ Nine sets of temperature detectors TC in each position ₂₁₁₁ , TC ₂₁₁₂ , TC ₂₁₁₃ , TC ₂₁₂₁ , TC ₂₁₂₂ , TC ₂₁₂₃ , TC ₂₁₃₁ , TC ₂₁₃₂ , TC ₂₁₃₃ (The drive section 129b has TC ₂₂₁₁ ~ TC ₂₂₃₃ ) Are arranged vertically.
[0026]
Further, the slow cooling zone 130 includes a plurality of shutter devices S at regular intervals along the longitudinal direction of the furnace body 124, as shown for the drive section 131a in FIG. ₁ , S ₂ , ~ S ₇ (S ₁ , S ₂ Only illustrated. Hereinafter, when there is no particular distinction, it is simply referred to as a shutter device S), and a plurality of, for example, six slow cooling zones 130 respectively corresponding to the drive sections 131a, 131b,. 1st soaking chamber to 6th soaking chamber, 1st heating chamber R ₁ , Second heating chamber R ₂ To 6th heating chamber R ₆ ( As will be described later, a plurality of heaters H for heating are provided, and hence the term “heating chamber” will be used instead of the soaking chamber. Also, When not particularly distinguished, it is simply referred to as a heating chamber R). In the present embodiment, the first heating chamber R ₁ To 6th heating chamber R ₆ Corresponds to a plurality of heating sections thermally partitioned from each other. As shown in the figure, the shutter device S ₁ Is between drive sections 129b and 131a, S ₂ Are provided between the drive sections 131a and 131b, and other shutter devices not shown are S _Three Thru S ₆ Between the drive sections 131b to 131f, S ₇ Are provided between the drive sections 131f and 133a, respectively.
[0027]
The shutter device S has a cross-sectional structure in FIG. 2 and a shutter device S in FIG. ₂ 2, for example, an upper fixed shutter 190 extending downward from an inner wall 210 positioned on the upper side in a plane perpendicular to the longitudinal direction of the furnace body 124, and a lower side, as shown in FIG. A lower fixed shutter 192 that extends upward from the inner wall 210 located at the center, and a rotary shutter that is formed in a flat plate shape parallel to them and is rotated about the axis of a rotary shaft 196 that is parallel to the roller 166. 194, and an opening 198 formed between the upper and lower fixed shutters 190 and 192 is opened or closed by the rotating shutter 194 so that the heating chambers R communicate with each other or are shielded. is there. The upper fixed shutter 190, the lower fixed shutter 192, and the rotating shutter 194 are all made of a heat-resistant glass plate made of the same material as the inner wall.
[0028]
FIG. 7 shows the shutter device S in FIG. ₂ The upper fixed shutter 190 and the lower fixed shutter 192 are each composed of a pair of heat-resistant glass plates that are provided in parallel to each other and have different heights. The shaft 196 is provided at a position between the pair of heat-resistant glass plates at the lower end position of the upper fixed shutter 190. The rotating shutter 194 extends from the rotating shaft 196 and is rotated within a range indicated by a one-dot chain line in the drawing. The upper fixed shutter 190 is positioned away from the transport surface 234 of the substrate 62 formed by the plurality of rollers 166 by a distance Hu of, for example, about 80 (mm), while the lower fixed shutter 192 is provided. Is spaced from the conveying surface 234 by a distance Hl of several (mm) to several tens (mm). For example, in a front plate and a rear plate for PDP, the thickness t of the substrate 62 is about 10 (mm) or less including the thickness of a setter (not shown) for carrying the normal substrate 62 and transporting it in the furnace. The substrate 62 is provided between the heating chambers R without interfering with the upper fixed shutter 190 and the rotating shutter 194 at the retraction angle position A because it is sufficiently thin as compared with the distance Hu. The opening 198 is passed through. Further, the center interval g between the rollers 166 is set to a uniform dimension of about 150 (mm) in each heating chamber R and at the boundary between them as shown in the figure.
[0029]
FIG. 8 is a diagram for explaining the drive structure of the rotating shutter 194, and is an enlarged view of a portion corresponding to the main part at the left end of FIG. 3 (d). FIG. It is a figure which shows the left side principal part. The rotating shaft 196 is provided so as to protrude outward from the side wall in a state of being rotatably supported by a pair of bearings 212 and 212 (only the left side is shown) provided on the side wall of the furnace body 124a. A flat arm 214 is attached to the tip of the projecting portion so as not to rotate relative to the axis of the rotation shaft 196. An air cylinder 216 extending in a direction substantially along the longitudinal direction of the furnace body 124 a is provided in the vicinity of the distal end portion of the rotating shaft 196, and the arm 214 protrudes from the air cylinder 216 in the conveyance direction of the substrate 62. Are attached to a connecting member 220 attached to the tip of a piston rod 218 provided so as to be relatively rotatable about the axis of a connecting shaft 222 parallel to the rotating shaft 196. Further, the air cylinder 216 is mounted on a bearing base 226 provided at the upper end of a fixing member 224 attached to the side surface of the furnace body 124a around the rotation shaft 230 parallel to the connecting shaft 222 by bearings 228 and 228. It is attached so that it can rotate relative to it. 8 and 9, reference numeral 232 denotes a through hole provided through the furnace body 124a to support the roller 166 outside the furnace. In FIG. 9, the fixing member 224 and the like are omitted.
[0030]
Therefore, in the state where the piston rod 218 shown by the solid line in FIG. 9 is most retracted, as shown in FIGS. 7 and 8, it is substantially parallel to the transport surface 234 of the substrate 62 formed by the plurality of rollers 166. Thus, by moving away from the transport surface 234, the rotating shutter 194 is positioned at the retraction angle position A that avoids interference with the transported substrate 62, while the most protruded state shown by the one-dot chain line in FIG. In FIG. 7, the rotary shutter 194 is positioned at a shielding angle position B indicated by a one-dot chain line in FIG. That is, when the piston rod 218 protrudes in the right direction from the state shown in FIG. 9, the rotating shaft 196 is rotated in the clockwise direction in FIG. Since it is rotated clockwise, the rotation shutter 194 is rotated clockwise in FIG. The rotating shutter 194 is attached to the rotating shaft 196 so as to be positioned at the retracting angle position A at the retracted position of the piston rod 218 and positioned at the shielding angle position B at the protruding position. As is clear from FIG. 7, a gap is provided between the rotating shutter 194 and the upper and lower fixed shutters 190 and 192 to prevent contact with each other. mm) and the thermal independence between the heating chambers R is sufficiently secured. In the air cylinder 216, an electromagnetic valve 238 provided on an air supply path 236 connected to an air supply source (not shown) is controlled for each heating chamber R by the control device 168 according to the transfer position of the substrate 62. As a result, the amount of pressurized air supplied through the air supply path 236 is adjusted, and the amount of protrusion of the piston rod 218 is controlled.
[0031]
Each drive section 131 of the slow cooling zone 130 includes a plurality of temperature detectors TC for detecting the temperature of each heating chamber R and a plurality for heating each heating chamber R, which are controlled by the control device 168, respectively. The heater H is arranged in the same arrangement pattern as the heating zone 128 shown in FIG. ₃₁₁₁ ~ TC ₃₁₃₃ And H ₃₁₁₁ ~ H ₃₁₄₆ In the drive section 131b, TC ₃₂₁₁ ~ TC ₃₂₃₃ And H ₃₂₁₁ ~ H ₃₂₄₆ , TC is included in the drive section 131c. ₃₃₁₁ ~ TC ₃₃₃₃ And H ₃₃₁₁ ~ H ₃₃₄₆ In the drive section 131d, TC ₃₄₁₁ ~ TC ₃₄₃₃ And H ₃₄₁₁ ~ H ₃₄₄₆ , The drive section 131e has TC ₃₅₁₁ ~ TC ₃₅₃₃ And H ₃₅₁₁ ~ H ₃₅₄₆ , The drive section 131f has TC ₃₆₁₁ ~ TC ₃₆₃₃ And H ₃₆₁₁ ~ H ₃₆₄₆ ). In each heating chamber R, air supply pipes 180 and 180 for supplying cooling air from above and below are provided on the rear side (upstream side) of the substrate 62 in the transport direction, and the cooling air is transported. An exhaust pipe 182 for discharging from the upper part on the front side (downstream side) is provided. The air supply pipe 180 and the exhaust pipe 182 are respectively the same as the air supply pipe 170 and the exhaust pipe 172 provided in the preheating zone 126, and a round hole nozzle 171 or a long hole nozzle 181 is provided. It consists of a tube made of alumina ceramics. The air supply pipe 180 and the exhaust pipe 182 are connected to an air supply pipe 184 and an exhaust pipe 186, respectively, provided outside the furnace body 124. The air supply pipe 180 is individually heated from an air supply source (not shown). Cooling air is guided through the air supply pipes 185a, 185b, to 185f (only the air supply pipe 185a is shown; hereinafter, simply referred to as the air supply pipe 185 unless otherwise specified) provided for each air supply pipe 184 of the chamber R. At the same time, the air in each heating chamber R sucked from the exhaust pipe 182 is discharged from the discharge port 188. Each air supply pipe 185 is provided with electromagnetic valves 208a, 208b, to 208f (only the electromagnetic valve 208a is shown. Hereinafter, when not particularly distinguished, it is simply referred to as the electromagnetic valve 208). The air supply is started and stopped, and the air supply amount is adjusted. In the figure, the supply pipes 184 and 184 respectively provided above and below the heating chamber R are connected to a common supply pipe 185, but are connected to separate supply pipes 185 each having an electromagnetic valve 208. It may be controlled independently.
[0032]
The cooling zone 132 includes a temperature detector TC for detecting the temperature in the cooling zone 132. ₄₁ , TC ₄₂ , T ₄₃ However, a plurality of cooling jackets C having a length approximately equal to the width dimension are provided on the upper side and the lower side of the furnace body 124 at the center in the width direction of the longitudinal center of the furnace body 124 for each drive section 133. Three rows are provided in the longitudinal direction of the furnace body 124 for each drive section 133. In the cooling jacket C, the cooling water supplied from the cooling water pipe 202 shown in FIG. 1 via the branch pipe 204 is circulated. The three cooling jackets C arranged one above the other are connected to each other, and the cooling water sequentially circulated through the three cooling jackets C is provided on the opposite side surface shown in FIG. Not discharged from drain pipe. The flow rate of the cooling water supplied to the cooling jacket C is adjusted by the solenoid valves 206a, 206b, and 206c provided in the branch pipe 204 for each drive section 133. The temperature detector TC and the electromagnetic valve 206 provided in the cooling zone 132 are also connected to the control device 168, and the cooling that is distributed to the cooling jacket C based on the temperature signal detected by the temperature detector TC. The amount of water is controlled.
[0033]
FIG. 10 is a diagram showing the configuration of the control device 168. The temperature in the furnace body 124 provided for each of the drive sections 127, 129, 131, 133 (or the heating chamber R) of the preheating zone 126, the heating zone 128, the slow cooling zone 130, and the cooling zone 132 is detected. Temperature detector TC for ₁₁₁ , TC ₁₁₂ , ~ TC ₄₃ Each signal indicating the temperature detected by is time-divided at a predetermined cycle by the multiplexer 68 and converted into a digital signal by the A / D converter 70 and then input to the arithmetic control circuit 72. The arithmetic control circuit 72 is constituted by, for example, a microcomputer, processes an input signal in accordance with a program stored in advance in a ROM while utilizing a temporary storage function of a RAM, and outputs a motor drive circuit MD via an output interface 74. ₁ A signal for continuously driving the first transport device 118 to the motor drive circuit MD ₂ Are supplied with signals for driving the drive section 127b of the first transport device 118 in synchronization with the drive speed of the second transport device 120, and each heater drive circuit D ₁₁₁₁ , D ₁₁₁₂ , ~ D ₃₆₄₆ To heater H ₁₁₁₁ , H ₁₁₁₂ , ~ H ₃₆₄₆ For driving the motor, and the motor drive circuit MD ₃₁ , MD ₃₂ , ~ MD ₃₆ A signal for intermittently driving the second transport devices 120a, 120b, to 120f is supplied to the cylinder drive circuit CD. _S1 , CD _S2 , ~ CD _S7 A signal for driving the air cylinders 216a, 216b, .about.216g for driving the rotary shutter 194 is supplied to the motor drive circuit MD. ₄₁ A signal for continuously driving the third transport device 122 to the motor drive circuit MD ₄₂ And a signal for driving the drive section 133a of the third transport device 122 in synchronization with the drive speed of the second transport device 120, respectively, and further, an electromagnetic valve drive circuit SD ₁ , SD ₂ , SD ₃ , SD _a1 , SD _a2 , ~ SD _a6 A signal for driving the solenoid valves 206a, 206b, 206c, 208a, 208b,... Therefore, in this embodiment, the control device 168 corresponds to a temperature control device.
[0034]
Each heater H described above ₁₁₁₁ , H ₁₁₁₂ , ~ H ₂₂₄₆ In the preheating zone 126 and the heating zone 128, the temperature of the furnace body 124 is uniform in the width direction and a predetermined temperature gradient is formed in the longitudinal direction (conveying direction of the substrate 62), and the heater H ₃₁₁₁ , H ₃₁₁₂ , ~ H ₃₆₄₆ Is controlled according to a preset target temperature ratio or a mutual output ratio so that the temperature in each heating chamber R of the slow cooling zone 130 becomes equal at a preset temperature. It has become. For example, the heater H located in the center in the width direction of the furnace body 124 ₁₁₁₂ , H ₁₁₁₃ , H ₁₁₂₂ , H ₁₁₂₃ , ~ H ₃₆₄₂ Compared to the heater H located at the end in the width direction ₁₁₁₁ , H ₁₁₁₄ , H ₁₁₂₁ , H ₁₁₂₄ , ~ H ₃₆₄₄ Output is increased. In addition, in the longitudinal direction of the furnace body 124, the low temperature side (the rear side in the transport direction of the substrate 62 in the drive section 129a of the preheating zone 126 and the heating zone 128, and the forward direction in the transport direction in the drive section 129b of the heating zone 128 and Heater H located on the side) ₁₁₁₁ , H ₁₁₁₂ , H ₁₁₁₃ , H ₁₁₁₄ , H ₁₂₁₁ , H ₁₂₁₂ , H ₁₂₁₃ , H ₁₂₁₄ , ~ H ₂₁₁₆ And H ₂₂₄₁ , H ₂₂₄₂ , H ₂₂₄₃ , H ₂₂₄₄ , H ₂₂₄₅ , H ₂₂₄₆ , H ₃₁₄₁ , H ₃₁₄₂ , H ₃₁₄₃ , H ₃₁₄₄ , H ₃₁₄₅ , H ₃₁₄₆ , ~ H ₃₆₄₆ Is the heater H located on the high temperature side (position opposite to the above) of each zone 126, 128, 130. ₁₁₄₁ , H ₁₁₄₂ , H ₁₁₄₃ , H ₁₁₄₄ , H ₁₂₄₁ , H ₁₂₄₂ , H ₁₂₄₃ , H ₁₂₄₄ , ~ H ₂₁₄₆ And H ₂₂₁₁ , H ₂₂₁₂ , H ₂₂₁₃ , H ₂₂₁₄ , H ₂₂₁₅ , H ₂₂₁₆ , H ₃₁₁₁ , H ₃₁₁₂ , H ₃₁₁₃ , H ₃₁₁₄ , H ₃₁₁₅ , H ₃₁₁₆ , ~ H ₃₆₁₆ The output is increased compared to
[0035]
11 and 12 show the position of each substrate 62 and the time t in FIG. 11 when the substrate 62 including the film forming material is baked using the continuous baking apparatus 116. ₀ 6 is a timing chart showing a temperature rising / falling curve of a substrate 62 carried into the board. In FIG. 11, the alternate long and short dash line indicates the boundary of each drive section 127 and the like, and in the slow cooling zone 130, as shown in the figure, it is equal to the boundary of each heating chamber R, that is, the heating section. That is, the vertical axis indicates the position in the longitudinal direction (transport direction of the substrate 62) in the furnace body 124. A plurality of solid curves drawn to the right correspond to the movement of each substrate 62, and the magnitude of the inclination represents the speed of the conveyance speed. Hereinafter, the firing method of the substrate 62 will be described with reference to these timing charts.
[0036]
First, time t ₀ , The unfired substrate 62 is carried in from the drive section 127 side of the preheating zone 126 according to the carrying-in direction shown in FIG. At this time, the shutter device S provided in the slow cooling zone 130 is all closed when the rotary shutter 194 is positioned at the shielding angle position B, and the heating chambers R are thermally separated from each other. The heater H provided in each zone 126, 128, 130 of the furnace body 124 is driven by feedback control so that the substrate 62 can be raised and lowered in the temperature curve shown in FIG. Is heated, and the electromagnetic valve 206 provided in the cooling zone 132 is driven so that cooling water flows through the cooling jacket C, whereby each part of each zone is held at a preset target temperature. . Further, the motor 134 and the motor 162 are driven to rotate the roller 166 in the first transport device 118 and the third transport device 122 in the clockwise direction in FIG. For this reason, the board | substrate 62 carried in is conveyed toward the heating zone 128 at the said 1st conveyance speed.
[0037]
Then time t ₀ For example, the time t after about 300 seconds from ₁ At time t when the next substrate 62 is carried into the preheating zone 126 and about 300 seconds have passed. ₂ Then, the next substrate 62 is carried into the preheating zone 126. That is, the substrates 62 are sequentially carried into the preheating zone 126 every about 300 seconds, for example. The substrates 62 sequentially carried in this way are conveyed to the end of the preheating zone 126 while being supported by the rotationally driven roller 166, for example, about 500 (° C.) in about 1100 seconds. The maximum firing temperature MT is increased. 11 and 12 t ₃ Time points indicate this state.
[0038]
In the subsequent heating zone 128, the substrate 62 is continuously transported from the preheating zone 126 by the first transport device 118 while being held at the maximum firing temperature MT. However, the conveyance speed in the heating zone 128 is initially set to the first conveyance speed in the same manner as the preheating zone 126, but when the substrate 62 completely enters the drive section 129b, the motor 150 is driven. The second transport speed is increased. At this time, the shutter device S provided between the heating zone 128 and the slow cooling zone 130. ₁ Is opened (the rotating shutter 194 is positioned at the retraction angle position A shown in FIG. 7 and the like) and the heating chamber R ₁ The second transport device 120a that drives the inner roller 166 is driven at a predetermined second transport speed (that is, a transport speed similar to that of the drive section 129b). Therefore, the substrate 62 is heated from the heating zone 128 to the heating chamber R in the slow cooling zone 130. ₁ That is, the first soaking temperature KT ₁ Heating chamber R held in ₁ It is quickly transported in. t ₄ The time point indicates this state. In this embodiment, the heating chamber R is reached after reaching the maximum firing temperature MT. ₁ The heating time (so-called keep time) until it is carried in is about 400 seconds, for example. Thus, the board | substrate 62 carried in to the slow cooling zone 130 is predetermined temperature (namely, 1st thru | or 6th soaking | uniform-heating temperature) KT preset in each heating chamber R. ₁ , KT ₂ , ~ KT ₆ The temperature is soaked for a predetermined period of time, soaked, and gradually cooled in accordance with the stepwise temperature drop curve shown in FIG. The first soaking temperature KT ₁ Is a temperature lower than the maximum firing temperature MT by a predetermined value ΔKT of about several (° C.) to several tens (° C.), and the second soaking temperature KT ₂ , Third soaking temperature KT ₃ To sixth soaking temperature KT ₆ Is a temperature further lowered by a predetermined value ΔKT.
[0039]
At this time, the substrate 62 is in the heating chamber R. ₁ The shutter device S that was opened when it was carried in ₁ Is closed and the motor 158a of the second transfer device 120a of the drive section 131a is driven in reverse, so that the substrate 62 is heated in the heating chamber R along the transfer direction. ₁ It is soaked while being reciprocated inside. In this way, when a predetermined holding time of, for example, about 180 seconds elapses, the reciprocation of the substrate 62 is stopped and the shutter device S is stopped. ₂ Is opened and the heating chamber R followed by the substrate 62 ₂ Conveyed in. T in FIG. ₅ The time point indicates this state. Substrate 62 is heating chamber R ₂ Shutter device S when completely inside ₂ Is closed and its heating chamber R ₂ Inside the heating chamber R ₁ Heating chamber R is vacant while being soaked in the same way as inside ₁ After cooling air is supplied from the air supply pipe 180 as necessary, the subsequent substrate 62 is carried in and subjected to a soaking process. Note that the time required for loading and unloading the substrate 62, that is, the time from when the shutter device S is opened to when it is closed again is, for example, about 30 seconds. Further, one cycle of heat treatment in each heating chamber R, that is, the interval at which the shutter device S on the rear side in the transport direction is opened in order to sequentially carry the substrate 62 is about 300 seconds, which is equal to the carry-in interval of the substrate 62 into the preheating zone. It is.
[0040]
For example, the cooling condition in the predetermined cooling period following the maximum firing temperature MT of, for example, about 500 (° C.) or more in the temperature rising curve shown in FIG. 12 is an important factor in the heat treatment of the substrate 62 including the film forming material. It is. For example, when used in a VFD (fluorescent display tube), PDP (plasma display panel), PALC (plasma addressed liquid crystal display), FED (field emission display), the substrate 62 is represented by soda lime glass. When the glass is made of a low strain point glass, the temperature in the substrate 62 is non-uniform and the cooling rate of each part is different from each other. It is difficult to align multi-layer thick film printing, or a cell cannot be configured due to a shift between the two when forming a large number of cells by combining the front and rear plate thick film printing surfaces. Since this produces a part, for example, the larger the size of 40 inches, the lower the production yield. FIG. 13 shows the dimension (solid line) of the substrate 62 in the conventional firing method in which the cooling rate on the front end side in the transport direction is higher than the cooling rate on the rear end side in the transport direction in comparison with the dimension before firing (one-dot chain line). Yes. Further, when a large number of thick printed resistors and thick film bonding pads are provided on the substrate 62, the temperature in the substrate 62 is non-uniform, and the cooling rates of the respective parts are different from each other. Depending on the degree of melting and softening of the glass component contained in the thick film layer having a function as a binder, and the degree of melting and sintering of the metal and inorganic material particles contained in the thick film, the resistance value and bonding suitability Therefore, as the substrate 62 becomes larger due to variations in the resistance value of the printed resistor and bonding suitability, the manufacturing yield is accelerated. Furthermore, even when a rib wall having a predetermined height is formed on the substrate 62 by laminating dielectric layers by thick film printing, the temperature in the substrate 62 is uneven and the cooling rates of the respective parts are different from each other. Then, since the firing shrinkage rate, that is, the film thickness and width dimension of the thick film is affected by the degree of melting and softening of the glass component contained in the thick film, the production yield is acceleratedly reduced as the substrate 62 becomes larger.
[0041]
As described above, the heating chamber R ₁ , R ₂ , ~ R ₆ When the heat treatment in the slow cooling zone is completed by being sequentially held in the shutter device S ₇ As the motor 158f and the motor 164 are driven, the drive sections 131f and 133a are driven in synchronism with each other, and the substrate 62 is heated. ₆ To the cooling zone 132. T in FIGS. 11 and 12 ₁₄ The time point indicates this state. Thereafter, the motor 164 of the third transport device 122 is stopped, and the substrate 62 is transported in the cooling zone 132 at the first transport speed and unloaded from its right end, and in the process, ascends as shown in FIG. It is rapidly cooled at a temperature drop rate that is substantially the same as the temperature rate. T in FIG. ₁₅ The time point indicates this state. The time required for this cooling process is, for example, about 700 seconds, and the time from when the substrate 62 is carried into the preheating zone 126 until the cooling is completed (t ₀ ~ T ₁₅ ) Is, for example, about 3500 seconds (about 1 hour). As described above, since the substrate 62 is sequentially loaded into the preheating zone 126 at a predetermined time interval of, for example, about 300 seconds, as is apparent from FIG. It will be sequentially carried out of the cooling zone 132 at intervals.
[0042]
As described above, according to the present embodiment, the continuous baking apparatus 116 is provided for each of the plurality of heating chambers R arranged in one direction, which is the transfer direction of the plurality of substrates 62 including the film forming material, in the cooling region. A second transport device 120 that transports the substrate 62 in one direction while supporting the plurality of substrates 62 by a control device 168 that controls soaking, and a plurality of rollers 166 that are driven to rotate about axes that are perpendicular to the longitudinal direction and parallel to each other. Between the roller 166 and the plurality of heating chambers R, the rotation angle parallel to the axial direction of the roller 166 between the shielding angle position B that shields the plurality of heating chambers R from each other and the retraction angle position A that avoids interference with the substrate 62 being conveyed. And a shutter device S provided with a flat-plate-like rotating shutter 194 that is rotated around the axis of the moving shaft 196. For this reason, the substrate 62 including the film forming material is transferred in one direction by the second transfer device 120 in the cooling process of the heat treatment. ₁ , R ₂ , ~ R ₆ Set temperature KT set for each of the plurality of heating chambers R so as to decrease stepwise along one direction as shown in FIG. ₁ , KT ₂ , ~ KT ₆ At a predetermined time (t ₄ ~ T ₅ ) Soaked. At this time, the plurality of heating chambers R are thermally independent from each other by the shutter device S when the rotating shutter 194 is positioned at the shielding angle position B located between the rollers 166, so that the heating chamber R The soaking state is preferably realized. In this way, the cooling process of the heat treatment is performed while repeating soaking sequentially in the plurality of heating chambers R respectively maintained at the set temperature KT set for each section so as to decrease stepwise in the process of being conveyed in one direction. As a result, the temperature variation in the substrate 62 including the film forming material is made as small as possible.
[0043]
Therefore, when the substrate 62 is made of glass, a local change in dimensions within the substrate 62 and misalignment such as thick film printing resulting therefrom are prevented, and the manufacturing yield is dramatically increased. In particular, when the substrate 62 is soda lime glass, the temperature is raised to a temperature equal to or higher than the strain point, so that the effect becomes remarkable. In addition, since the temperature variation in the substrate 62 including the film forming material is reduced as much as possible as described above, there are cases where a large number of thick film resistors and rib-like walls are provided on the surface of the substrate 62. Therefore, the degree of melting of the glass functioning as a binder in the thick film printed layer becomes uniform, and the variation in the resistance value of the thick film resistor and the variation in the height of the rib-like wall are suitably reduced. Is done.
[0044]
In addition, since the shutter device S is configured to shield the plurality of heating chambers R from each other by rotating the rotating shutter 194, the sliding portion as in the case where the shutter structure is a sliding type is a furnace. Therefore, problems such as generation of dust accompanying sliding and damage to sliding parts due to thermal expansion differences are unlikely to occur. Further, since the second transport device 120 supports the plurality of substrates 62 by a plurality of rollers 166 that are rotationally driven around the axis and transports them in one direction, the second transport device 120 is heated in the heating chamber. Since it is easy to carry out the transfer between the plurality of heating chambers R independently for each heating chamber R, the heat treatment of the substrate 62 is performed in the heating chambers R as compared with the case where all the heating chambers R are simultaneously transferred. It is possible to increase the processing efficiency of the substrate 62 by shortening the unoccupied movement time as much as possible. Further, as compared with the case of transporting by a mesh belt or the like, since there is no sliding of the belt that causes dust generation, the cleanliness in the furnace is increased and the substrate 62 is formed in the process of uniformly heat-treating. It is suppressed that the function of the film is damaged by the generated dust.
[0045]
Further, in the present embodiment, the shutter device S shields the plurality of heating chambers R from each other at positions Hu and Hl apart from the conveyance surfaces 234 of the plurality of substrates 62 formed by the plurality of rollers 166. Therefore, an upper fixed shutter 190 and a lower fixed shutter 192 that are fixedly provided are included. In this way, the plurality of heating chambers R are always shielded by the fixed shutters 190 and 192 in a range that is not hindered from being transported by the distance above the transport surface 234 of the substrate 62 at the boundary between them. The moving shutter 194 has a sufficient size to divide the remaining portion where the fixed shutters 190 and 192 are not provided, that is, the opening 198. Therefore, the roller 166 required to rotate the rotating shutter 194 even when the height of the heating area is set sufficiently large with respect to the thickness dimension t of the substrate 62 as in the present embodiment. Since the mutual gap g is sufficiently small, the gap g of the rollers 166 is the same as that of the other portions at the boundary of the heating chamber R, and there is no particular problem in the conveyance of the substrate 62. In addition, since the movable part of the shutter device S becomes small, it becomes easy to drive the rotation, and it is possible to prevent the drive from becoming difficult due to thermal deformation of the shutter.
[0046]
In the present embodiment, the second transfer device 120 intermittently transfers the plurality of substrates 62 for each of the plurality of heating chambers R. In this way, in the cooling process of the heat treatment, the heat treatment is sequentially performed in the plurality of heating chambers R while the substrate 62 is intermittently transferred in one direction. Compared to the case where the temperature difference in the substrate 62 is to be made extremely small by a conventional baking apparatus in which a continuous heat curve is formed by continuously transporting the substrate, the continuous baking apparatus has a reduced overall length. 116 becomes small.
[0047]
In addition, according to the present embodiment, since it is possible to use an inexpensive soda lime glass as the substrate 62 in manufacturing a large electronic device substrate, compared with the case of using a high strain point glass plate. Thus, there is an advantage that the glass is not easily cracked due to the difference in thermal expansion coefficient from the thick film layer at the time of firing.
[0048]
In the present embodiment, the plurality of rollers 166 provided in the transport device are made of alumina ceramics. For this reason, since the roller 166 brought into contact with the substrate 62 is made of ceramics, the roller 166 is heated in the furnace body 124 to be denatured or rusted to suppress generation of dust or the like. Therefore, the cleanliness in the furnace body 124 is further increased.
[0049]
Next, another embodiment of the present invention will be described. In the following embodiments, portions common to the above-described embodiments are denoted by the same reference numerals and description thereof is omitted.
[0050]
FIG. 14 is a diagram corresponding to the main part of FIG. 7, showing another configuration example of the shutter device S. In this embodiment, the rotation shaft 196 is provided at the same height position as the roller 166, and the rotation shutter 194 is counterclockwise from the retraction angle position A indicated by a solid line in the drawing that is substantially parallel to the conveyance surface 234. Is moved to the shielding angle position B indicated by a one-dot chain line in the drawing. That is, even when the rotation shaft 196 is provided below the transport surface 234 of the substrate 62 in this way, the same effect as in the case of FIG. 7 can be obtained. As indicated by the alternate long and short dash line in the figure, the rotating shutter 194 is brought into contact with the upper fixed shutter 190 at the shielding angle position B and completely separates the heating chambers R above the conveying surface 234. Therefore, a gap between the fixed shutters 190 and 192 and the rotating shutter 194 as shown in FIG. 7 is not necessarily provided. The shutter device S of the present embodiment can be driven by an air cylinder or the like as in the shutter device S of FIG. 7, but in this embodiment, the rotation direction from the retraction angle position A to the shielding angle position B is illustrated. Therefore, when the rotary shutter 194 is driven by the air cylinder 216 as shown in FIG. 9, for example, the piston rod 218 is located at the retraction angle position A at the protruding position and is retracted. The configuration may be opposite to that shown in FIG.
[0051]
15 and 16 are diagrams showing still another configuration example of the shutter device S. FIG. In the embodiments shown in both figures, the rotary shutter 194 extends from the rotary shaft 196 on both sides in a plane passing through the axis thereof, and is rotated upward and rotated by an upper rotary shutter 194a. The lower rotating shutter 194b is moved, and all of them are moved to the shielding angle position B by being rotated counterclockwise from the retraction angle position A in the drawing. In the embodiment of FIG. 15, the rotation shaft 196 is provided between the upper fixed shutter 190 and the transport surface 234, and the lower rotation shutter 194 b is the substrate 62 at the shielding angle position B indicated by the one-dot chain line. The upper rotation shutter 194 a is positioned so as to close the gap provided between the rotation shaft 196 and the upper fixed shutter 190.
[0052]
On the other hand, in the embodiment of FIG. 16, the rotation shaft 196 is provided between the lower fixed shutter 192 and the lower surface of the roller 166, and the upper rotation shutter 194a is located at the shielding angle position B indicated by the one-dot chain line. The lower rotation shutter 194 b is positioned so as to intersect with the transport surface 234, and the lower rotation shutter 194 b is positioned so as to close a gap formed between the rotation shaft 196 and the lower fixed shutter 192. Therefore, even when the two rotating shutters 194a and 194b are provided as described above, the heating chamber R is separated from each other by the rotation of the rotating shutter 194 as in the embodiment shown in FIG. The same effects as in the above-described embodiment can be obtained.
[0053]
As mentioned above, although one Example of this invention was described in detail with reference to drawings, this invention is implemented also in another aspect.
[0054]
For example, in the above-described embodiment, the substrate 62 is unloaded and loaded from the heating chamber R with a time difference, but may be performed simultaneously. For example, when the substrate 62 is transported so as to be housed in every other heating chamber R, three or more heating chambers R can be made continuous at the same time even if the heating chamber R is carried out and carried in at the same time. Therefore, the temperature and atmosphere in the heating chamber R are unlikely to change, and the high temperature uniformity in the heating chamber R is maintained as in the embodiment. Thus, when carrying in / out simultaneously, the 2nd conveying apparatus 120 is connected with the line shaft 138 and the miter gear 140 similarly to the 1st conveying apparatus 118 and the 3rd conveying apparatus 122, and drives with one motor. You can do that.
[0055]
In the embodiment, the rotating shutter 194 of the shutter device S is rotated by the piston rod 218 protruding and retracted from the air cylinder 216, but can be rotated by other driving means. For example, the rotation shaft 196 may be directly rotated by a motor, or a gear device such as a rack or a worm, a crank mechanism, a cam mechanism, or the like may be used.
[0056]
In the embodiment, the retraction angle position A of the rotary shutter 194 is provided in parallel with the transport surface 234. However, the retraction angle position A can be positioned at various angular positions as long as it does not interfere with the transported substrate 62.
[0057]
In the embodiment, the substrate 62 is reciprocated in the transport direction during the soaking process in the heating chamber R. However, since the soaking property is sufficiently improved in the heating chamber R, this reciprocation is performed. The movement does not necessarily have to be performed.
[0058]
In the embodiment, the first transport device 118 and the third transport device 122 transmit the rotation of the motor 134 or 162 by the line shaft 138 and the miter gear 140 and make the transport speed coincide with the second transport device 120. However, the drive sections 129b and 133a are provided with the motor 150 or 164, the one-way coupling 148, and the like so that the conveyance speed of the drive sections 129b and 133a can be changed. Similarly to the second transfer device 120, 133 a and 133 a may be provided with motors with variable rotation speeds and driven independently. In addition, all the drive sections of the first transport device 118 and the third transport device 122 may be driven independently.
[0059]
In the above-described embodiment, the glass 62 constituting the substrate 62 or the glass transition point or strain point contained in the thick film printed thereon is passed through the substrate 62 while maintaining a uniform temperature state. When the film forming material contained in the substrate 62 is fixed by melting or sintering of a metal or inorganic material, the melting point or sintering point of the film forming material is maintained at a uniform temperature in the substrate 62. The first set temperature KT so as to pass through ₁ Alternatively, the second set temperature KT ₂ Is set to a value in the vicinity of the transition point or strain point of the glass material contained in the substrate 62, or in the vicinity of the melting point or sintering point of the metal or inorganic material contained in the film forming material on the substrate 62. Set to a value.
[0060]
Further, in the embodiment, the furnace body 124 and the shutter device S are made of β-spodumene crystallized glass, and the roller 166 is made of alumina ceramics, but these may be made of other ceramics. For example, the furnace body 124 or the like may be made of alumina ceramics, mullite, or the like, and the roller 166 may be made of mullite, spodumene, or the like. In addition, in the roller hearth kiln using the roller 166 as in the continuous baking apparatus 116 of the embodiment, since it is not necessary to provide the sliding part in the furnace body 124, the material of each part has high heat resistance. You may comprise from metals, such as SUS310.
[0061]
In the embodiment, the rollers 166 are arranged at a uniform center distance g. However, for example, in the boundary portion of the heating chamber R, the rollers 166 may be widened in a range that does not hinder the transportability.
[0062]
In the embodiment, the shutter device S is composed of the fixed shutters 190 and 192 and the rotating shutter 194. However, when the height of the heating chamber R is sufficiently small with respect to the center interval g of the rollers 166, Alternatively, the shutter device S may be configured only from the rotating shutter 194, or the shutter device S may be configured from one of the upper fixed shutter 190 and the lower fixed shutter 192 and the rotating shutter 194.
[0063]
Although not illustrated one by one, the present invention can be implemented in variously modified and improved modes based on the knowledge of those skilled in the art.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating the overall configuration of a continuous firing apparatus according to an embodiment of the present invention.
2 is a view in which a part of the cross section along the longitudinal direction of the furnace body of the embodiment of FIG. 1 is omitted.
FIGS. 3A to 3E are views corresponding to cross-sectional views taken along lines aa to ee in FIG. 2, respectively.
FIG. 4 is a diagram illustrating a transport device according to the embodiment of FIG.
FIG. 5 is a diagram for explaining a plurality of heater arrangements in the embodiment of FIG. 1;
6A and 6B are views showing an air supply pipe and an exhaust pipe, respectively, of the embodiment of FIG.
FIG. 7 is an enlarged view of a part of FIG. 2 for explaining the configuration of the shutter device in detail.
FIG. 8 is a diagram illustrating a driving configuration of the shutter device by enlarging a part of FIG.
9 is a diagram showing a main part viewed from the left in FIG. 8;
10 is a block diagram illustrating a control circuit of the embodiment of FIG.
FIG. 11 is a time chart showing the substrate transfer position in the embodiment of FIG. 1;
12 is a diagram showing a set temperature of each zone of the embodiment of FIG. 1, that is, a firing temperature curve of the substrate.
FIG. 13 is a diagram for explaining local dimensional deformation of a substrate in a conventional baking apparatus.
14 is a view corresponding to the main part of FIG. 7 for explaining the structure of a shutter device according to another embodiment of the present invention.
15 is a view corresponding to the main part of FIG. 7 for explaining the structure of a shutter device according to still another embodiment of the present invention.
16 is a view corresponding to the main part of FIG. 7 for explaining the structure of a shutter device according to still another embodiment of the present invention.
[Explanation of symbols]
116: Continuous baking apparatus
{118: 1st conveyance device, 120: 2nd conveyance device, 122: 3rd conveyance device} (conveyance device)
H: Heater
R1, R2, ~ R6: Multiple heating chambers (heating division)
S: Shutter device
166: Roller
168: Control device (temperature control device)
{190: Upper fixed shutter, 192: Lower fixed shutter} (fixed shutter)
194: Rotating shutter

Claims (2)

A tunnel-like firing apparatus for performing uniform cooling treatment following heating to each of the plurality of substrates in a process of sequentially transporting a plurality of substrates including a film forming material in one direction,
A temperature control device for controlling soaking for each of a plurality of soaking sections provided side by side in the one direction in the slow cooling zone following the heating zone ;
In order to sequentially heat-treat each of the plurality of substrates in the plurality of soaking sections, the plurality of substrates are supported by a plurality of rollers that are each driven to rotate about axes that are perpendicular to the longitudinal direction and parallel to each other. And a conveying device for conveying in the one direction,
Between a shielding angle position that shields between the plurality of soaking sections between the plurality of rollers, and a retraction angle position that avoids interference with the plurality of substrates conveyed by the conveying device, A substrate baking apparatus including a film forming material, comprising: a shutter device including a flat-plate-like rotation shutter that is rotated about an axis parallel to the axial direction of the plurality of rollers. The shutter device is fixedly provided so as to shield the plurality of soaking sections from each other at a position separated by a predetermined distance or more from a conveyance surface of the plurality of substrates formed by the plurality of rollers. The apparatus for firing a substrate including a film forming material according to claim 1, further comprising a shutter.

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