JP2012109324A - Heat treatment apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the heat treatment hour and save heating power in a heat treatment of a glass substrate.SOLUTION: A heat treatment apparatus comprises a plurality of lower plane-shaped heaters 71 provided under a conveyance path on which a substrate is conveyed in a horizontal direction, which are separated in a row E in a center section, and rows D and F in both end sides in a width direction of the conveyance path. The center section E is set with higher heating power than the both end sides D and F. The row E of the lower plane-shaped heater 71 is maintained to have a temperature corresponding to heating of a tubular heater 71q, and at the same time, the temperature is maintained in almost half of electric power spaces 71w and 71x by heat conduction. A temperature corresponding to heat of tubular heaters 71r and 71s in the rows D and F is also maintained in almost half of the electric power spaces 71w and 71x by heat conduction. Electric power D and F of the tubular heater 71r and 71s are so low as to have a temperature according to Dh and Fh only, however, stored heat 63h of an inner wall of a frame body 6 is utilized for integration with the heat Dh and Fh so that the same temperature as Eh can be maintained.

Description

  The present invention relates to a heat treatment apparatus that performs heat treatment on a substrate such as a glass substrate for a flat panel display (FPD).

  In general, flat panel displays (FPDs) are manufactured using a photolithography process. The FPD photolithography process has three basic steps: a coating step for applying a resist on a glass substrate or the like, an exposure step for transferring a photomask pattern to a resist film, and a development step for developing the pattern after exposure. Various heat treatment steps are performed before and after these basic steps. For example, a heat treatment (dehydration bake) for removing moisture from the substrate is performed before the coating process. Between the coating process and the exposure process, a heat treatment (pre-baking) for evaporating the residual solvent is performed after the resist film is applied. After the development step, a heat treatment (post-bake) is performed to evaporate and remove the developer and cleaning solution remaining in the resist pattern.

  The conventional heat treatment (baking) apparatus is often configured as a hot plate oven. A glass substrate or the like is placed on the hot plate, and a chamber is formed by covering the lid from above. The substrate is heated to exhaust the solvent such as thinner that has volatilized from the resist film. In this type of heat treatment apparatus, in order to transfer the substrate to and from the transfer robot, a lift pin mechanism that raises and lowers the plurality of lift pins from the through hole of the hot plate to bring the substrate up and down, and a lid on the hot plate. A lid opening / closing mechanism that covers or opens upward is provided. Alternatively, the type in which the upper lid is fixed and the substrate loading / unloading port is provided on one side wall includes a gate mechanism for opening and closing the substrate loading / unloading port (see, for example, Patent Documents 1 and 2).

JP-A-8-313855 JP-A-11-204428

  However, the conventional heat treatment apparatus has a problem in that it takes a long time to carry in and out the substrate by raising and lowering the lifting pins and transferring the transfer robot, and the throughput is low. Further, in recent years, due to the increase in size of FPD, a huge glass substrate having a side of 2 m or more has appeared. In the conventional heat treatment apparatus, between the transfer arm and the lift pin or between the lift pin and the heating plate, There is a possibility that damage or particle generation may be caused by an impact at the time of delivery. In addition, since the heating plate generally has poor temperature responsiveness and is maintained at a predetermined temperature, in the conventional heat treatment apparatus, the temperature set after the glass substrate is placed on the heating plate. There is a concern that a considerable amount of power will be consumed because it takes a considerable amount of time to reach.

  The present invention has been made in view of the above-mentioned problems of the prior art, and realizes reduction of particles and energy saving while improving the processing speed without damaging the substrate even for a large glass substrate. It is an object of the present invention to provide a heat treatment apparatus that can be used.

  In order to solve the above problems, the present invention provides a heat treatment apparatus for performing heat treatment on a substrate, a conveyance path that conveys the substrate in one horizontal direction, and a substrate that surrounds the conveyance path. A frame body provided with an exhaust mechanism for exhausting inside at a center part in the transport direction and both ends in the transport direction, a plurality of upper face body heating parts disposed on the transport path, A plurality of lower face heating units disposed at a lower portion of the transport path, and one or both of the heating parts of the upper and lower face heating units are divided in a transport direction of the transport path, and the upper and lower face bodies At least the lower planar heating part of the shaped heating part is divided into a central part and both end parts in the width direction of the transport path, and the control unit is formed so that the both end parts can be controlled to a temperature lower than the divided central part. Is that And features.

  In the present invention, it is preferable that the upper and lower planar heating parts include a planar radiator and a tubular heater embedded in the radiator. In this case, a first tubular heater is embedded in a center portion in the width direction of the planar heating part, and a second tubular heater and a third tubular heater are respectively embedded in both sides in the width direction of the planar heating part. The second and third tubular heaters are preferably the same type of tubular heater, and more preferably, the end of the first tubular heater and the ends of the second and third tubular heaters extend in the width direction of the transport path. It is better to be separated by a predetermined distance. In this case, it is preferable that the first tubular heater is a sheathed heater, and the second and third tubular heaters are cartridge heaters.

  In the present invention, at least a part of the wall portion of the frame body has a double-wall structure including an inner wall and an outer wall that are provided with a space therebetween, and a space between the inner wall and the outer wall. However, it preferably functions as a heat insulating material that insulates the inside and outside of the frame and a heat insulating layer by air.

  According to the present invention, a frame provided so as to surround the transport path together with a transport path for transporting the substrate in one horizontal direction, and a plurality of planar body heating units disposed at the upper and lower portions of the transport path The pre-heating unit is divided into a conveyance direction and a width direction of the conveyance path, and by performing temperature control for each of the divided regions, it becomes possible to heat the substrate with high throughput and high uniformity.

  Further, an exhaust mechanism for exhausting the inside of the frame body is provided at the center and both ends of the frame in the transport direction, and the upper and lower heating units are respectively provided on both sides in the width direction of the transport path. By setting the heating power to be lower than that in the central portion in the width direction of the transport path, it becomes possible to perform the heat treatment with higher uniformity.

1 is a schematic plan view showing a coating / developing apparatus according to the present invention. It is sectional drawing of the plane direction of the heat processing apparatus lower part in this invention. It is sectional drawing of the side surface direction of the heat processing apparatus in this invention. It is a top view which shows a part of lower face-piece shaped heater in this invention in a cross section. It is a top view which shows a part of upper surface body-shaped heater in this invention in a cross section. It is the temperature control schematic diagram of the width direction division | segmentation of the lower face-shaped heater in this invention. It is the schematic sectional drawing (a) of the lower face-piece shaped heater in this invention, the heating power distribution figure (b) to the said lower face-piece shaped heater, and the temperature distribution figure (c) of the said lower face-piece shaped heater.

  The case where the heat treatment apparatus according to the present invention is applied to an FPD substrate resist coating / development processing apparatus will be described below.

  FIG. 1 shows a coating / development processing system as one configuration example to which the heat treatment apparatus of the present invention can be applied. The coating / development processing system 200 is installed in a clean room. For example, an FPD substrate is a substrate to be processed (hereinafter referred to as a substrate G), and cleaning, resist coating, pre-baking, development, and the like in a photolithography process in the FPD manufacturing process. Each process such as post-baking is performed.

  The coating / development processing system 200 is mainly composed of four blocks. A cassette station unit (C / S) 201 that transfers a cassette C containing a substrate G to and from an external device, an application line unit 202 that applies a chemical solution to the substrate G, and an interface unit (I that transfers a substrate to and from an exposure apparatus) / F) 203 and a development line unit 205 for developing the substrate G after exposure. The exposure apparatus 204 is installed adjacent to the interface unit 203.

  The cassette station section (C / S) 201 includes a cassette stage 10 on which up to four cassettes C in which a plurality of substrates G can be stacked and accommodated in a plurality of stages can be placed side by side in the horizontal direction, for example, the X direction. And a transport mechanism 11 for taking the substrate G in and out of the cassette C.

The transport mechanism 11 has a means capable of holding the substrate G, for example, a transport arm 12, and can be operated with four axes of horizontal X, Y direction, vertical Z direction, and horizontal rotation (θ), and adjacent coatings. The substrate G can be transferred to the line 202 and the development line 205.
In the coating line 202, an excimer UV irradiation unit (e-UV) 21, a scrub cleaning unit (SCR) 22, a preheat unit (PH) 23, and an adhesion unit (AD) are directed from the cassette station C to the interface unit 203. 24, a cooling unit (COL) 25, a resist coating unit (CT) 26, a reduced pressure drying unit (DP) 27, a heat treatment unit (HT) 28, and a cooling unit (COL) 29 are arranged in this order.

  The excimer UV irradiation unit (e-UV) 21 performs a removal process of organic substances contained in the substrate G, and the scrub cleaning unit (SCR) 22 performs a scrub cleaning process and a drying process of the substrate G. The preheat unit (PH) 23 heats the substrate G, the adhesion unit (AD) 24 performs hydrophobic treatment of the substrate G, and the cooling unit (COL) 25 cools the substrate G. The resist coating unit (CT) 26 supplies a resist solution onto the substrate G to form a resist film, and the reduced pressure drying unit (DP) 27 evaporates volatile components contained in the resist film on the substrate G under reduced pressure. To dry the resist film. A heat treatment unit (HT) 28, which will be described in detail later, heats the substrate G, and a cooling unit (COL) 29 cools the substrate G in the same manner as the cooling unit (COL) 25.

  In the developing line 205, a developing unit (DEV) 30, a heat treatment unit (HT) 31, and a cooling unit (COL) 32 are arranged in this order from the interface unit 203 toward the cassette station 201 side. In addition, between the cooling unit (COL) 32 and the cassette station 201, an inspection apparatus (IP) 35 for inspecting the substrate G subjected to a series of processes including resist coating and development is provided.

  The development unit (DEV) 30 sequentially performs the application of the developer onto the substrate G, the rinsing process of the substrate G, and the drying process of the substrate G. The heat treatment unit (HT) 31 heats the substrate G similarly to the heat treatment unit (HT) 28, and the cooling unit (COL) 32 cools the substrate G similarly to the cooling unit (COL) 25.

  The interface unit 203 receives a rotary stage (RS) 44 that is a transfer unit for the substrate G, in which a buffer cassette capable of accommodating the substrate G is disposed, and the substrate G that has been transported through the coating line 202 to receive the rotary stage (RS). And a transfer arm 43 for transferring to the transfer unit 44. The transfer arm 43 can be operated with four axes of horizontal X and Y directions, vertical Z direction, and horizontal rotation (θ), and an exposure device 204 provided adjacent to the transfer arm 43 and the transfer arm 43. Also, an external device block 90 having a peripheral exposure device (EE) and a titler (TITLER) provided adjacent to the developing unit (DEV) 30 is accessible.

  The coating / development processing system 200 is connected and controlled by the control device 101. The control device 101 includes an input keyboard including a keyboard for an operator to input commands for operating each part or each unit of the coating / development processing system 200, and a display display for monitoring the operating status of each part or each unit. Stores a recipe in which a control program and processing condition data for realizing various processes such as a heating process and a cooling process executed by the application / development processing system 200 under the control of the control device 101 are stored. Connected to the storage unit 103.

  If necessary, an arbitrary recipe is called from the storage unit 103 in accordance with an instruction from the input / output unit 102 and is executed by the control device 101, so that the desired application / development processing system 200 can control the control device 101. Is performed. In addition, recipes such as control programs and processing condition data use data recorded on a computer-readable storage medium, such as a CD-ROM, a hard disk, or a flash memory. It can also be transmitted and used online.

  In the coating / development processing system 200 configured as described above, first, the substrate G in the cassette C placed on the mounting table 100 of the cassette station 201 is upstream of the coating line 202 by the transport arm 12 of the transport device 11. The substrate G is transported to the side end and is subjected to dry cleaning by ultraviolet irradiation in the excimer UV irradiation unit (e-UV) 21. This UV cleaning mainly removes organic substances on the substrate surface. After completion of the ultraviolet cleaning, the roller is transported to a scrubber cleaning unit (SCR) 22 of the cleaning process unit 24.

  The scrubber cleaning unit (SCR) 22 removes particulate contamination from the surface of the substrate by brushing or blow cleaning the upper surface (surface to be processed) of the substrate G while transporting it in a horizontal orientation with rollers. To do. Note that the substrate G is dried with an air knife or the like while the substrate G is transported in a flat flow even after cleaning, and the substrate G is dried. The substrate G that has been cleaned in the scrubber cleaning unit (SCR) 22 is subjected to heat processing in the preheat unit (PH) 23 and dehydrated. The substrate G that has been subjected to the heat treatment in the preheat unit (PH) 23 is subjected to a hydrophobic treatment in the adhesion unit (AD) 24. The adhesion between the substrate G and the resist solution is improved by the hydrophobic treatment. The substrate G that has been subjected to the hydrophobization process in the adhesion unit (AD) 24 is cooled to a constant normal temperature by the cooling unit (COL) 25.

  A resist film is formed on the substrate G cooled by the cooling unit (COL) 25 by the resist coating unit (CT) 26. The substrate G is coated with a resist solution on the upper surface (surface to be processed) by spin coating or slit coating. The substrate G on which the resist film is formed by the resist coating unit (CT) 26 is transported on the transport line, and the resist film is dried by the reduced pressure drying unit (DP) 27 in a reduced pressure atmosphere.

  When the resist coating unit (CT) 26 is a spin coating method, both the upstream side 26i and the downstream side 26o of the resist coating unit (CT) 26 serve as a roller transport mechanism that transports the substrate G. . Further, when the resist coating unit (CT) 26 is of the slit coating method, 26i on the upstream side of the resist coating unit (CT) 26 is an air levitation used in the case of slit coating from the roller transport mechanism of the cooling unit (COL) 25. The downstream transfer unit 26o is a transfer unit from the air levitation transfer mechanism to the roller transfer mechanism of the vacuum drying unit (DP) 27.

  The substrate G that has been subjected to the drying process of the resist film by the reduced pressure drying unit (DP) 27 is transported through the transport line, and the solvent contained in the resist film is evaporated and removed by the heating process by the heat processing unit (HT) 28. . The heat treatment is performed while being transported on a transport line by a roller transport mechanism 5 described later. The detailed operation of the heat treatment unit (HT) 28 according to the present invention will be described later.

  The substrate G that has been subjected to the heat treatment in the heat treatment unit (HT) 28 is transported on the transport line and cooled by the cooling unit (COL) 29. The substrate G cooled by the cooling unit (COL) 29 is transported to the downstream end on the coating line, and then transported to the rotary stage (RS) 44 by the transport arm 43 of the interface unit 203. Next, the substrate G is transferred to the peripheral exposure apparatus (EE) of the external apparatus block 90 by the transfer arm 43, and an exposure process for removing an unnecessary outer peripheral portion of the resist film is performed by the peripheral exposure apparatus (EE). Is done.

  Subsequently, the substrate G is transported to the exposure device 204 by the transport arm 43, and a predetermined pattern exposure process is performed on the resist film. The substrate G may be transported to the exposure apparatus 204 after being temporarily stored in a buffer cassette on the rotary stage (RS) 44. After the exposure processing, the substrate G is transported to the titler 90 of the external device block 90 by the transport arm 43, and the product ID information is written in the titler 90 with predetermined information in two-dimensional code or OCR characters. Is done.

  A substrate G on which predetermined information is written by a titler 90 is transported on the development line 205, and a developing unit (DEV) 30 sequentially performs a developer coating process, a rinsing process, and a drying process. In the coating process, the rinsing process and the drying process of the developer, for example, the developer is deposited on the substrate G while the substrate G is transported on the transport line, and then the transport is temporarily stopped and the substrate is inclined at a predetermined angle. Then, the developing solution flows down, and in this state, the rinsing solution is supplied onto the substrate G, the developing solution is washed away, and then the substrate G is returned to the horizontal posture and the drying gas is sprayed onto the substrate G while being transported again. Done in

  After the processing of the developing solution in the development unit (DEV) 30 is completed, the substrate G is transported on the transport line, and is heated in the heat processing unit (HT) 31, so that the solvent and moisture contained in the resist film are removed. Evaporated off. The heat treatment is performed while being transported on the transport line by the roller transport mechanism 5. Note that an i-line UV irradiation unit that performs a decoloring process of the developer may be provided between the development unit (DEV) 30 and the heat treatment unit (HT) 31. The substrate G that has been subjected to the heat treatment in the heat treatment unit (HT) 31 is transported on the development line 205 and cooled by the cooling unit (COL) 32.

  The substrate G cooled by the cooling unit (COL) 32 is transported through the development line 205 and inspected by the inspection unit (IP) 35. The substrate G that has passed the inspection is accommodated in a predetermined cassette C mounted on the mounting table 100 by the transfer arm 12 of the transfer device 11 provided in the cassette station 201.

  Next, the heat treatment of the substrate G in the heat treatment units (HT) 28 and 31 configured as described above will be described with reference to FIG. The heat treatment unit (HT) 28 is transported from the reduced pressure drying unit (DP) 27 side, and the substrate G transported from the heat treatment unit (HT) 31 is from the development unit (DEV) 30 side) passes through the substrate carry-in port 61. When it passes, it is delivered to the roller transport mechanism 5, and is heated in the frame 6 by the upper and lower planar heaters 81 and 71 whose temperature is controlled by the hot plate controller 104 while being transported by the roller transport mechanism 5.

  In this way, since the substrate is transported and heated in parallel, the processing time can be shortened. Since the substrate G is heated from the upper and lower sides by the upper and lower face-piece-shaped heaters 81 and 71, the occurrence of warping is suppressed. When the substrate G transported by the roller transport mechanism 5 passes through the carry-out port 62, it is delivered to the transport mechanism on the cooling unit (COL) 29 side (the cooling unit (COL) 32 side in the heat treatment unit (HT) 31)). .

  Next, the heat treatment unit (HT) 28 will be described in detail. Since the heat treatment unit (HT) 31 has the same structure as the heat treatment unit (HT) 28, the heat treatment unit (HT) 28 will be described as a representative here.

  FIG. 2 is a plan view showing a lower heating portion of the heat treatment unit (HT) 28 (heat treatment apparatus), and FIG. 3 is a side view. The heat treatment unit (HT) 28 includes a roller transport mechanism 5 that transports the substrate G toward one side in the Y direction, a frame body 6 provided so as to surround or store the roller transport mechanism 5, Are provided with heating mechanisms 7 and 8 for heating the substrate G being roller-conveyed by the roller-conveying mechanism 5.

  In the roller transport mechanism 5, a plurality of rows of substantially cylindrical rotatable roller members 50 extending in the X direction are arranged at intervals in the Y direction. Each of the roller members 50 is connected to a motor (not shown) directly or indirectly via a gear or the like and rotated by driving the motor, whereby the substrate G moves over the plurality of roller members 50 in the Y direction. It is transported toward one side.

  The roller members 50 each have a shape that is in contact with the entire width direction (X direction) of the substrate G, and the roller outer peripheral surface portion 52 is configured to prevent the heat of the substrate G heated by the heating mechanism 7 from being transmitted. Is made of a material having a low thermal conductivity such as a resin, and the rotary shaft 51 is a shaft using a ferritic stainless steel having high strength and high corrosion resistance.

  The frame 6 is formed in a box shape and can accommodate the substrate G in a substantially horizontal state, and a slit-shaped substrate carry-in port 61 and a substrate carry-out port 62 are arranged in the substrate carrying direction (Y direction). The roller members 50 of the roller transport mechanism 5 are disposed in the frame body 6 such that the rotation shafts 51 are rotatably supported by bearings 60 provided on the side walls facing the X direction of the frame body 6.

  The wall portion of the frame 6, here, the upper wall portion, the bottom wall portion, and the side wall portions facing each other in the Y direction have a double wall structure including an inner wall 63 and an outer wall 64 provided with a space therebetween. The space 65 between the inner wall 63 and the outer wall 64 functions as an air heat insulating layer that insulates the inside and outside of the frame body 6. On the inner side surface of the outer wall 64, a heat insulating material 66 for insulating the inside and outside of the frame body 6 is provided.

  The heating mechanism 7 includes a lower face heater 71 (71a to 71o) which is a lower face heating portion provided in the frame 6 along the transport path of the substrate G by the roller transport mechanism 5. The heater 71 is provided on the back surface (lower surface) side of the substrate G transported by the roller transport mechanism 5 so as to be close to the substrate G transported by the roller transport mechanism 5.

  The heating mechanism 8 includes an upper face heater 81 (81a to 81h) that is an upper face heating section provided in the frame 6 along the transport path of the substrate G by the roller transport mechanism 5. The upper planar heater 81 is provided on the surface (upper surface) side of the substrate G transported by the roller transport mechanism 5 so as to be close to the substrate transported by the roller transport mechanism 5.

  In the case of a material having a large distortion of the substrate G during heating, the upper surface heater 81 (81a to 81h) on the front surface (upper surface) side is replaced with the lower surface heater 71 (71a to 71a) provided on the back surface (lower surface) side. It is also possible to reduce distortion by making the upper and lower heat distributions uniform by arranging them in the same arrangement as 71o) and symmetrically in the vertical direction.

  The lower planar heater 71 is divided and formed in the X direction, and is provided between the roller members 50 and is arranged in a plurality in the Y direction (71a to 71o in order from the upstream side in the Y direction). The upper planar heater 81 is attached to and supported by, for example, a side wall portion facing the X direction of the frame body 6. When the heating of the substrate G is controlled in more detail, the upper planar heater 81 may be divided and formed in the X direction.

  The exhaust of heat in the frame 6 is provided with an exhaust port 67 at the center in the transport direction and at the upper wall of both ends, and an exhaust device 68 is connected to the exhaust 67. The exhaust device 68 is configured to exhaust the inside of the frame body 6 through the exhaust port 67. For example, a plurality of exhaust ports 67 may be formed in the X direction, or may be formed in a slit shape extending in the X direction.

  By providing exhaust mechanisms at both ends in the Y direction of the frame body 6, air curtains are formed at the carry-in entrance 61 and the carry-out exit 62, and external particles enter the frame 6 through the carry-in entrance 61 and the carry-out exit 62. Is suppressed. In addition, since an exhaust flow in the Y direction is formed in the same direction as the transport direction of the substrate G, particles generated inside the frame 6 are also exhausted without generating turbulence, and thus are prevented from adhering to the substrate G. can do.

  In FIG. 3, the exhaust port 67 is arranged at the upper part of the frame body 6. However, when it is desired to increase the amount of heat and solvent exhausted, or to exhaust a large amount of particles, the exhaust port 67 is also provided at the lower part symmetrical to the upper exhaust port 67. May be provided. Further, the upper wall portion of the frame 6 can be opened and closed at the center position in the transport direction (Y direction) to facilitate the leaning of the solvent evaporated and adhering to the inner wall 63 and the internal maintenance.

  Next, the overall temperature control of the lower planar heater 71 will be described with reference to FIG. A temperature command to be set in the hot plate controller 104 is sent from the control device 101. The hot plate controller 104 issues a set temperature command to the hot plate power source 105. In this case, the hot plate power source is divided into six blocks 105a, 105b, 105c, 105d, 105e, and 105f. The lower planar heater 71 also corresponds to the hot plate controller 104 on the Y axis in the transport direction for every six blocks 71a to 71b, 71c to 71d, 71e to 71g, 71h to 71j, 71k to 71m, 71n to 71o. It is arranged. The heating power for each block can be controlled on a block-by-block basis because the temperatures at the inlet, center, outlet, and width direction of the substrate G differ depending on the airflow and the heat accumulation deviation of the inner wall.

  The hot plate controller 105 is divided into S, T, and U corresponding to the division of D, E, and F in the width direction of the lower face heater 71. For example, the blocks D of the lower face heaters 71a to 71b are controlled by S of the hot plate power source 105a. Similarly, the E block of the lower body heaters 71a to 71b is controlled by T of the hot plate power source 105a, and the F block of the lower body heaters 71a to 71b is controlled by the U of the hot plate power source 105a. S, T, and U of other hot plate power supplies 105b to 105f are also controlled in accordance with D, E, and F of lower body heaters 71c to 71d, 71e to 71g, 71h to 71j, 71k to 71m, 71n to 71o. I do.

  Here, the temperature distribution of the heat treatment device 28 (31) will be described with reference to FIG. 3. The exhaust of heat in the frame 6 is provided with exhaust ports 67 at the center portion in the transport direction and the upper wall portions at both ends. An exhaust device 68 is connected to the exhaust port 67. In addition, since the substrate carry-in port 61 and the substrate carry-out port 62 are open, the temperatures at the center and both ends are lowered even when the same power is applied to the lower face heater 71 and the lower face heater 81. Moreover, the both ends of the conveyance direction of the board | substrate G become high with the heat storage of the frame inner wall 63 shown in FIG. Since the temperature is different even when the same power is applied in this way, it is necessary to be able to control the lower face heater 71 and the upper face heater 81 for each block in the transport direction (Y axis). Therefore, the lower planar heater 71 performs fine control by dividing it into three blocks of D, E, and F in the width direction (X axis) of the substrate G.

  FIG. 4 is a plan view showing a part of the lower planar heater 71 in cross section. The entire lower surface heater 71 is dissipated by a heat dissipating body 71p such as aluminum, stainless steel or ceramic. 4 is performed by two parallel tubular heaters 71q embedded in the heat radiating body 71p. The temperature sensing is sensed by the sensor 71t, and the sensed temperature is input to the hot plate controller 104 via the hot plate power source 105. The hot plate controller 104 issues a temperature increase / decrease command according to the sensed temperature. In response to the command, the hot plate power supply 105 supplies power to the hot plate. In the rows D and F at both ends of the radiator 71p, the temperature of the tubular heaters 71r and 71s disposed with the blank areas (spaces) 71w and 71x between the tubular heater 71g is the temperature sensor 71v and the tubular heater 71r. Is controlled by a temperature sensor 71r.

  In FIG. 4, one tubular heater 71r, 71s is arranged for two tubular heaters 71p. In contrast to the two tubular heaters 71p corresponding to the center E row, the one tubular heaters 71r and 71s corresponding to the D and F rows at both ends supply low heating power. The reason is that the temperature of 71r and 71s is maintained even if the calorific value is low due to the heat storage effect of the side wall portion of the frame body 6. The tubular heaters 71p and 71r, 71s may be the same number of tubular heaters.

  Next, the temperature distribution of the hot plate will be described with reference to FIG. In FIG. 7a, the lower face heater 71 that heats the lower portion (back surface) of the substrate G is divided into an E row at the center and a D row and an F row at both ends. The upper part (surface) of the substrate G is heated by an upper face heater 81.

  FIG. 7B schematically shows the power applied to the planar heater. The thermal power applied to the E row, which is the central portion of the lower planar heater 71, and the thermal power applied to the D row and the E row at both ends are set high in the central portion. In addition, there are blank areas (spaces) 71w and 71x for heating power between both ends of the radiator 71p and the tubular heater 71g. This can also be confirmed by FIG.

  FIG. 7C is a schematic diagram of the actual temperature distribution. Although the temperature corresponding to the heating of the tubular heater 71q is maintained in the E row of the lower planar heater 71, the temperature is maintained to almost half of the power spaces 71w and 71x by heat conduction at the same time. Similarly, the heat of the tubular heaters 71r and 71s is also maintained by heat conduction up to almost half of the power spaces 71w and 71x. Since the electric powers D and F of the tubular heaters 71r and 71s are low electric power, the temperature is only Dh and Fh. However, heat transfer of the heat storage 63h on the wall surface portion of the frame body 6 is generated and integrated with the heat of Dh and Fh, and becomes the same temperature as the temperature of Eh.

  The electric power spaces 71w and 71x can adjust the integrated temperature by moving the tubular heaters 71r and 71s in the X direction. By this adjustment, the temperature at the center and both ends of the lower face heater 71 is equalized. As shown in FIG. 4, the central tubular heater 71q may be formed by a sheathed heater, and the tubular heaters 71r and 71s at both ends may be formed by a cartridge heater.

  In the structure of the sheathed heater, a coil-shaped heating wire (nichrome wire) is inserted into a metal pipe, and a heat-resistant insulating material having high electrical insulation and thermal conductivity is filled and enclosed between the heating wire and the metal pipe. Therefore, it is possible to prevent the generation of particles. Electrical wiring is arranged at both ends of the heater. With this structure, it is embedded in the center of the lower face heater, that is, the central tubular heater 71q. The sheathed heater thus formed is excellent in mechanical strength such as vibration and impact.

  The structure of the cartridge heater is excellent in high thermal conductivity and high insulation between the heating wire and the pipe by inserting a heating wire (nichrome wire) wound around a rod (eg ceramic) into a pipe (eg stainless steel). For example, it is enclosed with magnesium oxide (MgO). Since the cartridge heater can be wired only in one direction, the heater can be inserted into the hole of the metal block and heated, and the temperature can be adjusted by adjusting the length of the insertion. Further, in the case of the cartridge heater, it is possible to adjust the uniformity of the generated temperature by inserting the cartridge heater at both ends of the planar heater and adjusting the distance from the sheathed heater. The cartridge heater formed in this way is suitable as a heater that resists vibration and does not generate particles.

  Thus, by forming the central tubular heater 71q with a sheathed heater and the tubular heaters 71r and 71s at both ends with a cartridge heater, the substrate G according to the present invention is a glass substrate for a flat panel display. In the case of a size larger than a meter, even if the vibration of the conveyance for conveying the substrate G is intense, the substrate G can withstand the vibration. Further, the circuit pattern on the flat panel display is becoming extremely fine, and it is an important issue to reduce the generation of particles as much as possible.

  As shown in FIG. 3, the upper body heater 81 includes seven upper body heaters 81 a to 81 h arranged on the upper surface (front surface side) of the substrate G. Among them, the upper planar heaters 81d and 81e divide the width of the upper planar heaters 81a to 81c and 81f to 81h from the middle. This is because the upper wall portion of the frame 6 is opened and closed at the center position in the transport direction (Y direction) to perform maintenance and internal cleaning.

  FIG. 5 is a plan view showing a part of the upper planar heater 81 in cross section. The upper planar heater 81 is basically the same as the control method of the lower planar heater 71 but is not divided in the X direction. In addition, three tubular heaters 81q are embedded in the radiator 81p. The temperature of the generated heat is detected by the sensor 81t. It is controlled by the hot plate controller 104 via the hot plate power source 105 of FIG. In addition, the upper face body heaters 81d and 81e have one tubular heater embedded therein.

  As described above, according to the heat treatment apparatus of the embodiment, heat treatment is possible while transporting the substrate G, so that the processing time can be shortened, and the turbulent airflow can be reduced by making the airflow flow the same as the transport direction of the substrate G. The generation of particles can be prevented, the generation of particles can be prevented, and the structure of the planar heaters 71 and 81 and the heat plate controller 104 can be used to store the heat on the side wall surface of the heat treatment apparatus, thereby realizing energy saving and heating the substrate G. Can be achieved.

  Note that the heat treatment apparatus according to the present invention is suitable particularly when the substrate is large, such as a glass substrate for FPD, but is not limited to the glass substrate, but for heat treatment of other substrates such as a semiconductor wafer. Can also be widely applied.

G Substrate 5 Roller transport mechanism 6 Frame 7 Heating mechanism 8 Heating mechanism 50 Roller member 61 Substrate carry-in portion 62 Substrate carry-out portion 63 Frame inner wall 64 Frame outer wall 65 Air heat insulating layer 66 Heat insulating material 71 (71a to 71o) Lower face body shape Heater (lower face heating unit)
71p radiator 71q-71s tubular heater 71t-71v temperature sensor 71w, 71x heating power space 81 (81a-81h) upper face heater (upper face heating section)
101 Control Device 104 Hot Plate Controller 105 Hot Plate Power Supply

Claims (6)

In a heat treatment apparatus for performing heat treatment on a substrate,
A transport path for transporting the substrate in one horizontal direction;
A frame body that is provided so as to surround the transport path, and is provided with an exhaust mechanism for exhausting the inside at a central portion in the transport direction of the substrate and both ends in the transport direction;
A plurality of upper body heating parts disposed on the upper part of the conveying path;
A plurality of lower face-shaped heating units disposed at the lower part of the conveyance path;
Either or both heating parts of the upper and lower body heating parts are divided in the transport direction of the transport path,
At least the lower face-shaped heating part of the upper and lower face-shaped heating parts is divided into a center part and both end parts in the width direction of the transport path,
By the control device, the both end portions are formed so as to be controllable to a temperature lower than the divided central portion,
The heat processing apparatus characterized by the above-mentioned.   2. The heat treatment apparatus according to claim 1, wherein the upper and lower planar heating parts include a planar radiator and a tubular heater embedded in the radiator. 3.   A first tubular heater is embedded in a center portion in the width direction of the planar body heating portion, and a second tubular heater and a third tubular heater are embedded in both side portions in the width direction of the planar body heating portion, respectively. The heat treatment apparatus according to claim 1, wherein the three tubular heaters are the same kind of tubular heater.   The end of the first tubular heater and the ends of the second and third tubular heaters are separated from each other by a predetermined distance in the width direction of the transport path. Heat treatment device.   The heat treatment apparatus according to claim 3 or 4, wherein the first tubular heater is a sheathed heater, and the second and third tubular heaters are cartridge heaters.   At least a part of the wall portion of the frame body has a double wall structure including an inner wall and an outer wall provided with a space between each other, and a space between the inner wall and the outer wall extends outside the frame body. The heat treatment apparatus according to any one of claims 1 to 5, wherein the heat treatment apparatus functions as a heat insulating material for heat insulation and a heat insulating layer made of air.

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