JP3910206B2 - Multistage heating system for large substrates - Google Patents

Description

  The present invention relates to a multi-stage heating apparatus for large substrates used for heating and drying large substrates such as liquid crystal display panels (LCDs) and plasma display panels (PDPs), and in particular, simplification of structure, production / operation costs. The present invention relates to a multi-stage heating apparatus for large substrates that reduces costs such as the above.

  In the manufacture of large substrates such as liquid crystal display panels (LCDs) and plasma display panels (PDPs), the removal of moisture after cleaning the substrate and the removal of solvents etc. contained in the composition of the chemical applied on the substrate Therefore, heating and drying processes are indispensable. A multi-stage heating apparatus may be used to simultaneously perform the heating / drying process performed on the large substrate on a plurality of large substrates.

  This multi-stage heating device arranges multiple large substrates, which are to be dried, in multiple stages in the vertical direction, and in accordance with this, arranges multiple shelf heaters in multiple stages to heat the large substrates in each stage. The drying process is performed simultaneously by heating with a shelf heater in each stage, and the exhaust system for the generated steam, solvent vapor, etc. is made common. Such a multistage heating apparatus can significantly reduce the installation area, and is therefore suitable for simultaneously heating and drying a large number of large substrates.

  In the multi-stage heating furnace for large substrates introduced in Japanese Patent Application Laid-Open No. 2001-317872, a shelf heater arranged in each stage is a double-sided heating type panel heater (radiation plate) in which far infrared rays are emitted from both sides. These are arranged at a constant pitch in the vertical direction, and a space between adjacent upper and lower shelf heaters is a drying chamber. Thus, by using a double-sided heating type shelf heater, the heater is thinned and the installation height is greatly reduced, and a significant space saving can be achieved.

  The heating element embedded in each shelf heater is divided into a plurality of zones in the depth direction of the device, and the heating temperature of the heating element in each zone can be set arbitrarily. Thus, the surface heating temperature of the large substrate that is the object to be heated is made uniform.

  Also, each side wall of the furnace body is provided with side heaters for auxiliary heating made of far-infrared panel heaters so as to face the inside of the furnace. In addition to being heated, the peripheral portion thereof is also heated by the side heater, so that the entire surface of the large substrate can be heated, and the accuracy of the surface heating temperature is further improved.

  Further, in this multistage heating furnace, gas passages are formed inside the shelf heaters of each stage, and airs flowing through the gas passages are blown out from holes opened in the lower surface of the shelf heaters and dried. Accompanied with indoor steam, solvent vapor, etc., it is collected in the furnace body surrounding the drying chamber by the down blow method, and is then sucked and exhausted outside through the exhaust holes provided in the side wall of the furnace body. The high cleanliness of the atmosphere is maintained.

  As described above, this multi-stage heating furnace for large substrates has various ideas in terms of reduction of installation space, uniformity of surface heating temperature and improvement of accuracy of large substrates, and maintenance of cleanness of the atmosphere in the furnace. Applied to improve the dry quality of large substrates.

  However, this multi-stage heating furnace for large substrates is complicated in structure and has a high manufacturing cost and operating cost, such as a down blow system being adopted for the exhaust system. Further, since the large substrate is supported in each drying chamber by a pair of left and right support jigs, the substrate may be bent or cause non-uniform heating.

  The invention of the present application solves the above-mentioned problems of the conventional multistage heating apparatus for large substrates, has a simple structure, excellent processing efficiency, and can maintain a higher drying quality of large substrates. Another object of the present invention is to provide a multi-stage heating apparatus for large substrates that can reduce costs such as production cost and operation cost.

  According to the invention of the present application, such a problem is caused in the multistage heating apparatus for large substrates used for arranging and drying a plurality of rectangular large substrates that are to be dried in a multistage manner. A plurality of double-sided heating-type rectangular panel heaters with heating elements are arranged in multiple stages at predetermined intervals in the vertical direction, and the space between adjacent upper and lower panel heaters heats and dries the large substrate The large-sized substrate is supported at a plurality of appropriate positions on the plate surface by a plurality of support pins, held at a predetermined height position in the drying chamber, and formed in multiple stages in the vertical direction. This is solved by a multi-stage heating apparatus for large substrates, wherein a rising hot air flow is formed surrounding the plurality of drying chambers.

  According to the multistage heating apparatus for a large substrate, in a plurality of drying chambers formed in multiple stages in the vertical direction, the large substrate is supported by a plurality of support pins at a plurality of appropriate positions on the plate surface. The drying chamber is held at a predetermined height and simultaneously radiantly heated by adjacent upper and lower panel heaters, and the drying chamber is formed by a rising hot air stream formed around a plurality of drying chambers formed in multiple stages in the vertical direction. Since it is kept warm, a large number of large substrates can be heated and dried quickly and efficiently.

  In addition, due to the support using a plurality of support pins, the large substrate is heated uniformly, and water vapor, solvent vapor, etc. generated in the drying chamber are sucked and exhausted by the rising hot air flow, and the drying chamber is highly clean. Therefore, it is possible to obtain a large substrate having high dry quality with little drying unevenness.

  In addition, since this rising heat airflow can use a naturally formed airflow, there is no need to install a side panel heater for keeping the drying chamber warm, and water vapor, solvent vapor in the drying chamber is not necessary. It is not necessary to apply special structural measures such as the formation of a special airflow passage for forcibly exhausting etc., and the structure of panel heaters, furnace walls, etc. can be simplified, reducing production costs and operating costs. You can save.

  Accordingly, a multi-stage heating apparatus for a large substrate that has a simple structure, excellent processing efficiency, can maintain high dry quality of a large substrate, and can reduce costs such as manufacturing cost and operation cost is provided. be able to.

In a preferred embodiment, in this multistage heating apparatus for large substrates, the four corners of the panel heater are supported by support columns, and a plurality of panel heaters are arranged in multiple stages at predetermined intervals in the vertical direction. The column supporting one of the four corners of the panel heater is fixed, and the column supporting the remaining one of the four corners of the panel heater is movable in the horizontal direction. Thermal expansion / contraction is allowed.
As a result, due to the heat generated by the panel heater, the panel heater itself is warped, dented, and expanded and contracted by heat, preventing thermal deformation of the panel heater and preventing uneven drying on the large substrate being dried. And a higher dry quality of the large substrate can be maintained. Moreover, the bad influence with respect to the support member of an apparatus can be prevented.

In another preferred embodiment, in the multistage heating apparatus for large substrates, the heating element is embedded in the vicinity of the peripheral edge of the panel heater along the peripheral edge.
As a result, the heat of the panel heater is easily dissipated to the outside, and the vicinity of the peripheral edge of the panel heater is more easily carried away by the hot air flow that rises around each drying chamber compared to other parts. Since the built-in heating element is more actively heated, the overall temperature of the panel heater is uniform, and the heat generation temperature distribution is made uniform, so that the large substrate can be heated and dried uniformly. Quality can be maintained. In addition, since the panel heater is not heated entirely, but only near the periphery, it can be heated uniformly, so that it is possible to reduce equipment such as thermal equipment and control equipment, which also reduces the cost. it can.

Furthermore, in another preferable embodiment, in this multistage heating apparatus for large substrates, a temperature sensor is embedded in the vicinity of an arbitrary corner of the panel heater.
As a result, the temperature in the vicinity of an arbitrary corner of the rectangular panel heater can be measured by a temperature sensor embedded therein, and the heating element usually has a heating value equal to the length direction. Therefore, as described above, the temperature near any one corner of the rectangular panel heater can be measured, so that the temperature near the remaining three corners of the rectangular panel heater can be estimated, and based on this temperature By controlling the heat generation temperature of the panel heater, the panel heater is maintained at a predetermined uniform temperature in the steady state, so that uniform heating / drying processing of a large substrate can be performed. Combined with the fact that the heating element is embedded in the vicinity of the peripheral edge of the panel heater along the peripheral edge, it is possible to simplify the heating temperature control of the panel heater.

Hereinafter, an embodiment of the present invention will be described.
The multistage heating apparatus for large substrates in this embodiment is mainly used for heating and drying large substrates such as liquid crystal display panels (LCD) and plasma display panels (PDP).
In the manufacturing process of such a large substrate, the large substrate is usually heated and dried in order to remove moisture after cleaning the substrate and to remove solvents contained in the composition of the chemical applied on the substrate. It is essential to apply treatment. Multi-stage heating devices are suitable for heating and drying a large number of large substrates while saving installation space because multiple large substrates are placed in multiple stages and heated and dried at the same time. Yes.

  Next, the structure of the multistage heating apparatus for large substrates in this embodiment will be described. As shown in FIG. 1, the multi-stage heating apparatus 1 for large substrates in the present embodiment has a plurality of (n) rectangular (planar) planar views on a frame 3 at the bottom of the furnace surrounded by the furnace wall 2. Panel heaters 4-1, 4-2,..., 4-n are supported at their four corners by pillars 5 and arranged in multiple stages at predetermined intervals in the vertical direction. And between adjacent upper and lower panel heaters, that is, between the panel heater 4-1 and the panel heater 4-2, between the panel heater 4-2 and the panel heater 4-3,... n-1) and the space between the panel heaters 4-n are drying chambers 7-1, 7-2,... 7- (n−) for heating and drying the substrate 6 to be dried. 1). The substrate 6 has a rectangular shape in plan view, a large size with one side extending from 1.0 to 2.0 m, and a thickness of about 1 mm to several mm. The panel heater 4-m (m = 1, 2,..., N) is also rectangular in plan view according to the shape of the substrate 6, but its area is larger than the area of the substrate 6.

  The column 5 can be a single rod-shaped body that passes through each stage, but in this embodiment, divided columns that are divided for each level are used, and these divided columns are stacked. Thereby, the support | pillar 5 is formed. These divided columns are arranged between the gantry 3 and the lowermost panel heater 4-1, between adjacent upper and lower panel heaters, and between the uppermost panel heater 4-n and a ceiling plate 13 described later. These four corners are spaced apart from each other in the up-down direction and assembled in a three-dimensional manner. The lower end of the column 5 arranged at an arbitrary one of the four corners is embedded in a frame 3 made of steel or the like (see section A in FIG. 1) and fixed, while supporting the remaining three corners. The column 5 is movable in the horizontal direction around the fixed column, and allows thermal expansion / contraction of the panel heater 4-m.

  As shown in FIGS. 3, 4, 6 to 9, the panel heater 4-m is configured by sandwiching and embedding a heating element 11 between two upper and lower plates made of an aluminum material. , A double-sided heating type plate heater that emits radiant heat from the upper and lower surfaces thereof as shown by the thick arrows in FIG. 4 and the drying chambers 7- (m-1), 7-m below and above it. The substrates 6 set in the above are simultaneously heated. However, since a sub-plate 8-m, which will be described later, is placed on the upper surface of the panel heater 4-m, actually, the radiant heat is emitted through the sub-plate 8-m, and the drying chamber 7 above the sub-plate 8-m. The substrate 6 set to −m is heated. However, the sub plate 8-m is not essential in the present embodiment.

  The heating element 11 is a resistance heating element, has a uniform heat generation amount per unit length, and is embedded in the vicinity of the periphery of the panel heater 4-m along the periphery. The form of the heating element 11 is not limited to the resistance heating element, and a heat medium using gas or liquid may be used.

  The substrate 6 is not placed directly on the panel heaters 4-1, 4-2,..., 4- (n-1), but as shown in FIGS. Further, sub-plates 8-1, 8-2,..., 8- (n-1) made of an aluminum material having good thermal conductivity are mounted on the panel heaters, respectively. A plurality of supporting pins 9 respectively planted at 8-m (m = 1, 2,... (N-1)) support a plurality of appropriate positions including the central portion and the peripheral portion of the substrate 6 ( 2, 7), 7-(n) separated from the upper surface of each panel heater 4-m and the upper surface of each sub-plate 8-m by a predetermined length. -1) is set at a substantially central portion in the vertical direction.

  Accordingly, the substrate 6 set in the drying chamber 7-m (m = 1, 2,... (N-1)) is located below the adjacent upper and lower panel heaters 4- (m + 1), 4-m. From the panel heater 4-m, the sub-plate 8-m placed thereon receives the heat generated by the panel heater 4-m by heat conduction and radiates it, and the upper panel heater 4- (m + 1). ), Both surfaces thereof are simultaneously heated by the radiant heat radiated from itself.

  However, the space below the lowermost panel heater 4-1 is not actually used as a drying chamber, and the stainless plate 12 is laid on the surface of the gantry 3 so that the lowermost panel heater 4- The radiant heat radiated from the lower surface of 1 is reflected so that the space here becomes a high temperature environment similar to the drying chamber 7-m, and the lowermost drying chamber 7-1 and the intermediate drying chamber 7-m. No temperature gradient is generated between (1 <m <(n-1)). Similarly, the space above the uppermost panel heater 4-n is not actually used as a drying chamber, and a ceiling plate 13 backed with a stainless steel plate is stretched. The radiant heat radiated from the sub-plate 8-n placed on the heater 4-n is reflected so that the space becomes a high temperature environment similar to the drying chamber 7-m, and the uppermost drying is performed. A temperature gradient is not generated between the chamber 7- (n-1) and the intermediate drying chamber 7-m (1 <m <(n-1)). Hereinafter, these high-temperature environment spaces are referred to as a lower auxiliary drying chamber 7L and an upper auxiliary drying chamber 7U.

  In the drying chambers 7-1, 7-2,... 7- (n-1) of the substrate 6, not only a plurality of appropriate positions are supported by the plurality of support pins 9, but also FIG. As shown in FIG. 10 and FIG. 10, each of the four corners is positioned by two positioning pins 10 disposed so as to sandwich two orthogonal sides thereof, whereby the sub-plate 8-m It is accurately positioned at a predetermined position on the horizontal plane at a predetermined height position from the upper surface of (m = 1, 2,... (N−1)). Such setting of the substrate 6 is automatically performed by a robot (not shown). The positioning pin 10 is implanted in the movable piece 22 so that the position thereof can be adjusted according to the size of the substrate 6. The movable piece 22 can change the screwing position on the upper surface of the sub-plate 8-m within a predetermined range.

  As shown in FIG. 2, the sub-plate 8-m has a rectangular shape in plan view that is substantially similar to the panel heater 4-m, and is slightly narrower than the panel heater 4-m. Then, the sub-plate 8-m is placed on the upper surface of the panel heater 4-m, or the front side of the sub-plate 8-m in the direction of insertion / removal so as to be convenient when taking it out for maintenance. A pair of grips 14 are respectively attached to the side edge on the maintenance work side and the side edge on the anti-maintenance work side that is the front side of the sub-plate 8-m in and out. FIG. 10 illustrates a state in which the sub plate 8-m is removed from the panel heater 4-m.

  In addition, the sub-plate 8-m is positioned at a predetermined position when it is placed on the upper surface of the panel heater 4-m. As shown in the drawing, positioning members 15 and 16 are fixed to the left and right corners of the sub-plate 8-m, respectively, and the panel heater 4-m is engaged with the positioning members 15 and 16 respectively. Positioning members 17 and 18 are respectively fixed to corresponding portions (near the left and right corners of the panel heater 4-m on the near side of the sub-plate 8-m in the insertion / removal direction).

  The positioning member 15 has a left upper end projecting in a round shape in FIG. 11 and is fitted into a V-shaped groove at the lower end of the positioning member 17 in FIG. , 17 are engaged. Further, the positioning member 16 has a right upper end protruding in a round shape in FIG. 11, and abuts against a flat surface below the positioning member 18 in FIG. 11, so that both the positioning members 16 and 18 are engaged. Match. In this engaged state, the corner portions of the positioning members 15 and 16 are screwed to the panel heater 4-m by the lock pins 19, respectively, and the sub-plate 8-m is fixed to the panel heater 4-m. . In this way, displacement and rotation of the sub plate 8-m on the horizontal plane are prevented.

  On the anti-maintenance work side of the sub-plate 8-m, as shown in FIGS. 2 and 12, along the side edge of the sub-plate 8-m, a pair of left and right presser plates 20 and a presser at the center portion. A plate 21 is fixed to the upper surface of the panel heater 4-m. These presser plates (pressing members) 20 and 21 receive the side edges of the subplate 8-m in the inward recesses between them and the upper surface of the panel heater 4-m, and this subplate 8-m The side edges are warped or dented by heat to prevent thermal deformation.

Next, the exhaust structure of water vapor, solvent vapor, etc. generated in each of the drying chambers 7-1, 7-2... 7-(n−1) will be described.
As shown in FIG. 1, an outside air inlet 27 is formed at an appropriate position below the furnace wall 2 of the multistage heating apparatus 1, and an exhaust port 28 is formed at the ceiling. ing. Therefore, the outside air taken in from the outside air intake 27 is the hot air in each of the lower auxiliary drying chamber 7L, the drying chambers 7-1, 7-2... 7- (n-1), and the upper auxiliary drying chamber 7U. And it heats by the heat | fever of the structure surrounding each of these chambers, and becomes a rising hot airflow (refer arrow B of FIG. 4, FIG. 5). Then, heat is appropriately removed from each of these chambers and structures, and various gases (water vapor, solvent vapor, etc.) and particles generated inside the apparatus are sucked and taken in, and flow out from the exhaust port 28. Since this rising hot air flow is due to natural convection caused by the outside air being heated exclusively inside the apparatus, the consumption of pump power is small.

  On the other hand, as shown in FIG. 1 to FIG. 5, double walls for forming a rising hot air flow are formed on the peripheral walls of the panel heaters 4-1, 4-2. The structures 23-1, 23-2,... 23-n are fixed by a fixing tool such as a bolt. Further, a double wall structure 24 for forming a rising hot air flow having a substantially similar structure is fixed to the peripheral wall of the ceiling board 13 by a fixing tool such as a bolt around the four circumferences. The double wall structure 24 may be slightly shorter in width (height) than the double wall structures 23-1, 23-2,.

  Each of these double wall structures 23-1, 23-2... 23-n, 24 is shown in FIG. 4 and FIG. The inner bent plate 26 and the outer bent plate 26 are separated from each other by a space S in the horizontal direction and arranged in parallel. It is configured by being assembled. And the upper end part is extended to the up-down direction approximate center part of each surrounding opening part of drying chamber 7-1, 7-2 ... 7- (n-1) and the upper auxiliary drying chamber 7U.

  The inner bent plate 25 is made of an aluminum material, both inner and outer surfaces are processed in black, and an upper portion thereof is bent inward. Further, the outer bent plate 26 is made of stainless steel, the inner surface thereof is processed into black, the upper portion thereof is bent inward, and the lower portion thereof is separated from the lower portion of the inner bent plate 25. In this manner, the outer bent plate 25 is bent outward and slightly extended downward from the lower portion of the inner bent plate 25. The black processing of the inner and outer surfaces of the inner bent plate 25 and the black processing of the inner surface of the outer bent plate 26 are performed by coating these surfaces with a black paint kneaded into Teflon (registered trademark). Yes.

  Due to such shapes of the inner and outer bent plates 25, 26, the lower portions of the double wall structures 23-m (m = 1, 2,... N), 24 having these as constituent elements are directed downward. It opens in a divergent shape and takes in a wide flow of air, and the middle part becomes a straight air flow path directed upward, and the upper part directs this air flow slightly inward to the drying chamber 7-m ( m = 1, 2,... (n-1)) and the upper auxiliary drying chamber 7U can flow out toward the upper part of each peripheral opening.

The double wall structures 23-m (m = 1, 2,... N), 24 are configured as described above, and as already described, the multistage heating apparatus 1 includes a lower portion. Since the surroundings of the auxiliary drying chamber 7L, the drying chambers 7-1, 7-2,. In the state in which the double wall structures 23-m, 24 are arranged above and below at a predetermined interval, most of the rising thermal airflow inside the apparatus is inside the double wall structures 23-m, 24. It flows through the flow path (see arrow C in FIGS. 4 and 5).

  The hot air flow rising in the lower double-wall structure 23-m is directed slightly inward toward the upper part of the peripheral opening of the drying chamber 7-m at the outlet, It is pushed back to the hot air flow in the drying chamber 7-m, and is pulled by the hot air flow rising in the upper double wall structure 23- (m + 1), so that the upper double wall structure 23- ( It is sucked into m + 1). In this way, a plurality of drying chambers 7-1, 7-2... 7-(n−1) and the upper auxiliary drying chamber 7 U that are formed in multiple stages in the up and down direction are connected to each other, and by the rising hot air flow. An air curtain is formed. Water vapor, solvent vapor and the like filling each drying chamber 7-m are sucked by this rising hot air flow (see arrow D in FIGS. 4 and 5), taken into this, and exhausted from the exhaust port 28.

  During this time, the airflow flowing through the flow path between the inner and outer bent plates 25 and 26 by the black heat treatment effect on each surface is better maintained, so that the airflow flowing into each drying chamber 7-m is also kept warm. Therefore, the substrate 6 in each drying chamber 7-m can maintain a stable temperature distribution without being affected by outside air. The flow of the hot air flow is an air curtain by an updraft and is formed so as to surround the periphery of the panel heater 4-m arranged in multiple stages, so that the temperature of each drying chamber 7-m is further stabilized.

  Further, in the process in which water vapor, solvent vapor or the like filling each drying chamber 7-m is taken in and exhausted by an ascending hot air flow (air curtain), black and white processing is performed on each surface of the inner and outer bent plates 25 and 26. Because of the heat retention effect, the airflow flowing through the flow path between them is better insulated, so that solidification of water vapor, solvent vapor, etc. can be prevented. Furthermore, adhesion of water vapor, solvent vapor, various particles, and the like to these plate surfaces is prevented by the action of Teflon contained in the black processing applied to each surface of the inner and outer bent plates 25 and 26. As a result, a smooth flow of the rising hot air stream can be formed.

  As shown in FIG. 1, each of the double wall structures 23-1, 23-2,... 23-n for forming a rising hot air stream has a door (not shown) of the multistage heating apparatus 1. ), The notches 29 are formed at two left and right portions over a predetermined length, leaving the thicknesses of the panel heaters 4-1, 4-2,..., 4-n. These notches 29 are provided so that it is convenient for a robot hand (not shown) to put the substrate 6 on and out of each drying chamber 7-m (m = 1, 2,... (N-1)). It is what was done.

  Each panel heater 4-m (m = 1, 2,..., N) has a temperature sensor 30 in the vicinity of an arbitrary corner as shown in FIGS. Is buried. As described above, the heating element 11 of the panel heater 4-m is embedded in the vicinity of the periphery of the panel heater 4-m along the periphery, and generates heat uniformly. The temperature near one corner is measured by the temperature sensor 30 to control the heat generation temperature. A thermo switch 31 is embedded in the vicinity of the temperature sensor 30 to prevent excessive temperature rise of the panel heater 4-m.

Since the multi-stage heating apparatus 1 for large substrates in the present embodiment is configured as described above, a robot hand (not shown) moves the substrates 6 to the drying chambers 7-m (m = 1, 2,...). (n-1)) is set on the plurality of support pins 9 in, when each panel heaters 4-m a (m = 1,2 ··· n) is maintained at a predetermined temperature, the drying chamber 7 The substrate 6 in -m has both sides simultaneously due to the radiant heat radiated from the sub-plate 8-m placed on the lower panel heater 4-m and the upper panel heater 4- (m + 1). Heated and dried quickly. And the water vapor | steam, solvent vapor | steam, etc. which generate | occur | produce during this heating / drying process flowed to the surrounding opening part of the drying chamber 7-m, and went up the flow path in the double wall structure 23-m. The air is sucked by the hot air flow, taken in, and exhausted from the drying chamber 7-m.

  And the rising heat flow which took in water vapor | steam, solvent vapor | steam, etc. in this way flows through the upper double wall structure 23- (m + 1), 23- (m + 2) ... 24 one by one, and the room | chamber interior there The air curtain surrounding each of the drying chambers 7-m and the upper auxiliary drying chamber 7U is formed while taking in the water vapor, the solvent vapor, and the like, and is exhausted from the exhaust port 28 together with other rising thermal airflow.

Since the multistage heating apparatus 1 for large substrates according to the present embodiment is configured as described above, the following effects can be obtained.
In the plurality of drying chambers 7-1, 7-2,. The upper and lower panel heaters 4- (m + 1), 4-m which are respectively supported and held at predetermined height positions in the drying chamber 7-m (m = 1, 2,... (N-1)). Simultaneously, the inside of the drying chamber 7-m is kept warm by the rising hot air flow formed around the plurality of drying chambers 7-m formed in multiple stages in the vertical direction. The large substrate 6 can be quickly and efficiently heated and dried.

  In addition, the large substrate 6 is heated uniformly by the support using the plurality of support pins 9, and water vapor, solvent vapor and the like generated in the drying chamber 7-m are sucked and exhausted by the rising hot air flow. Since the inside of each drying chamber 7-m is maintained in a high cleanliness and high temperature atmosphere, it is possible to obtain a large substrate 6 having high dry quality with little drying unevenness.

In addition, the rising hot air flow is naturally formed by Runode Ki out utilizing air flow, without the need for installation of the side panel heater for thermal insulation of the drying room 7-m, also, dried Panel heater 4-m (m = 1, 2,... Need not be specially devised, such as forming a special airflow passage for forced exhaust of water vapor, solvent vapor, etc. in chamber 7-m. -The structure of n) and the furnace wall 2 etc. can be simplified and manufacturing cost and operation cost can be reduced.

  Accordingly, the large-scale multi-stage heating apparatus 1 for a large substrate that has a simple structure, excellent processing efficiency, can maintain high dry quality of the large substrate 6, and can reduce costs such as production cost and operation cost. Can be provided.

  The large panel heater 4-m has a large thermal expansion and has a great influence on the support member of the apparatus, but the column 5 supporting one corner of the panel heater 4-m is fixed, and the panel heater is fixed. The support column 5 that supports the remaining corners of the four corners of 4-m is movable in the horizontal direction around the fixed support column 5 so that the panel heater 4-m can be thermally expanded and contracted. Since the panel heater 4-m itself generates heat, the panel heater 4-m itself is prevented from thermal deformation of the panel heater 4-m that warps, dents, or expands and contracts due to heat. Drying unevenness is further reduced in the large substrate 6 that is an object to be dried, and the higher dry quality of the large substrate 6 can be maintained. Moreover, the bad influence with respect to the support member of an apparatus can be prevented.

  Furthermore, since the heating element 11 is embedded in the vicinity of the peripheral edge of the panel heater 4-m along the peripheral edge, the heat of the panel heater 4-m is easily dissipated to the outside. The vicinity of the peripheral edge of the panel heater 4-m that is easily carried away by the hot air flow (air curtain) that rises around -m is more actively heated by the built-in heating element 11 than other parts. Therefore, if it sees as the whole panel heater 4-m, heat_generation | fever temperature distribution is equalized, the large sized board | substrate 6 can be heated and dried uniformly, and the still higher dry quality of the large sized board | substrate 6 can be hold | maintained. . Moreover, since the panel heater 4-m is not heated over the entire surface, but only in the vicinity of the periphery, it is possible to reduce equipment such as thermal equipment and control equipment, which also reduces costs. can do.

  Furthermore, since the temperature sensor 30 is embedded in the vicinity of an arbitrary corner of the panel heater 4-m, the temperature sensor 30 embedded in the temperature of an arbitrary corner of the rectangular panel heater 4-m is embedded. Since the heating element 11 normally has the same calorific value in the length direction, as described above, the temperature near any corner of the rectangular panel heater 4-m can be measured. By being able to measure, the temperature in the vicinity of the remaining three corners of the rectangular panel heater 4-m can be estimated, and if the heat generation temperature of the panel heater 4-m is controlled based on this temperature, the steady state is obtained. In the state, since the entire surface of the panel heater 4-m is maintained at a predetermined uniform temperature, the large-sized substrate 6 can be uniformly heated and dried, and the heating element 11 is attached to the panel heater. In the vicinity of the periphery of the over 4-m, it can with or mutually 俟 embedded along the peripheral edge, it is possible to simplify the heating temperature control panel heaters 4-m. In addition, various effects can be achieved.

  The invention of the present application is not limited to the above embodiment, and various modifications can be made without departing from the scope of the invention.

FIG. 1 is an overall schematic perspective view seen through a furnace wall of a multistage heating apparatus for a large substrate according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of the drying chamber portion of the multistage heating apparatus for large substrates.
3 is a cross-sectional view taken along line III-III in FIG.
FIG. 4 is a partially enlarged view of FIG.
FIG. 5 is a partially enlarged view of FIG. 1 for explaining the flow of the airflow.
FIG. 6 is a plan view of a panel heater used in the multi-stage heating apparatus for the large substrate.
FIG. 7 is a side view of the panel heater.
FIG. 8 is an enlarged view of a portion where the temperature sensor of FIG. 6 is embedded.
FIG. 9 is a side view of FIG.
FIG. 10 is a plan view of a sub plate placed on the panel heater, and shows a state in which the sub plate is pulled out from the drying chamber.
FIG. 11 is a plan view of a positioning mechanism on one side of the sub plate.
12 is a cross-sectional view of the positioning mechanism on the other side of the sub-plate, and is a cross-sectional view taken along line XII-XII in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Multistage heating apparatus for large substrates, 2 ... Furnace wall, 3 ... Base, 4-1, 4-2 ... 4-n ... Panel heater, 5 ... Post, 6 ... Substrate, 7-1, 7- 2 ... 7- (n-1) ... drying chamber, 7L ... lower auxiliary drying chamber, 7U ... upper auxiliary drying chamber, 8-1, 8-2 ... 8-n ... sub-plate, 9 ... support pin DESCRIPTION OF SYMBOLS 10 ... Positioning pin, 11 ... Heat generating body, 12 ... Aluminum plate, 13 ... Ceiling board, 14 ... Handle, 15-18 ... Positioning member, 19 ... Lock pin, 20-21 ... Holding plate, 22 ... Movable piece, 23 -1, 23-2... 23-n, 24... Double wall structure for forming ascending hot air flow 25. Inner folding plate 26. Outer folding plate 27 27 Outside air intake port 28 Exhaust port , 29 ... Notch, 30 ... Temperature sensor, 31 ... Thermo switch for preventing excessive temperature rise.

Claims (4)

A multi-stage heating apparatus for large substrates used for arranging and drying a plurality of rectangular large substrates to be dried in multiple stages,
A plurality of double-sided heating type rectangular panel heaters that have heating elements inside, their four corners are supported by pillars , arranged in multiple stages at predetermined intervals in the vertical direction,
The upper auxiliary drying chamber is brought to a high temperature environment by radiant heat radiated from the upper surface of the uppermost panel heater, and the radiant heat radiated from the lower surface of the lowermost panel heater is made a high temperature environment. A lower auxiliary drying chamber,
The space between adjacent upper and lower panel heaters between the upper auxiliary drying chamber and the lower auxiliary drying chamber is a drying chamber for heating and drying the large substrate,
The large-sized substrate is supported at a plurality of appropriate positions on the plate surface by a plurality of support pins, and is held at a predetermined height position in the drying chamber,
A multistage heating apparatus for a large substrate, wherein an ascending hot air stream is formed surrounding a plurality of drying chambers formed in multiple stages in the vertical direction. A column supporting one corner of the four corners of the panel heater is fixed,
The support column supporting the remaining corners of the four corners of the panel heater is movable in the horizontal direction to allow thermal expansion / contraction of the panel heater. 2. A multistage heating apparatus for large substrates according to 1. The multi-stage heating apparatus for a large substrate according to claim 1 or 2, wherein the heating element is embedded along the periphery only in the vicinity of the periphery of the panel heater. 4. The multistage heating apparatus for large substrates according to claim 3, wherein a temperature sensor is embedded near an arbitrary corner of the panel heater , and a thermo switch for preventing excessive temperature rise is provided .

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