JP6053468B2 - Levitation transfer heat treatment equipment - Google Patents

Description

  The present invention relates to a levitation conveyance heat treatment apparatus that heats and cools a substrate while levitation conveyance of the substrate.

  A flat panel display such as a liquid crystal display or a plasma display uses a substrate coated with a resist solution (referred to as a coated substrate). The coated substrate is produced by forming a coating film by uniformly applying a resist solution on the substrate by a coating apparatus, and then drying the coating film by a heat treatment apparatus.

  As this heat treatment apparatus, for example, there is a floating conveyance heat treatment apparatus as shown in Patent Document 1 and FIG. As shown in FIG. 8, the levitation transfer heat treatment apparatus 90 has a heating region 91, and the substrate W is heated by the temperature of the heating region 91 itself while the heating region 91 floats the substrate W by ultrasonic vibration. Since the substrate W can be heated in a non-contact manner, the coating film on the substrate W can be dried without causing drying unevenness.

  Further, by providing a plurality of drying devices 91 having different set temperatures, not only drying of the coating film but also baking (baking) can be performed while the substrate W is floated and conveyed.

  The substrate W heated by the levitation transfer heat treatment apparatus 90 is transferred to a cooling unit 92 such as an air levitation unit that cools the substrate W with blown air or a water-cooled metal plate, and is mounted on the cooling unit 92. It is cooled to near room temperature by being placed and then transferred to a downstream process apparatus.

Japanese Patent Application No. 2011-74335

  However, the levitation transfer heat treatment apparatus 90 shown in Patent Document 1 and FIG. 8 has a problem that it takes time to cool the substrate. Specifically, in order to transfer the substrate W from the levitation transfer heat treatment apparatus 90 to the cooling unit 92, the transfer robot 93 between the levitation transfer heat treatment apparatus 90 and the cooling unit 92 transfers the substrate W from the levitation transfer heat treatment apparatus 90. Since the receiving robot 93 needs to place the substrate W on the cooling unit 92, if this time is included in the cooling time of the substrate W, the cooling time may not be within the range of the cooling time that can be prepared by the user. .

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a levitation transfer heat treatment apparatus capable of cooling a heated substrate in a short time.

  In order to solve the above problems, the levitation transfer heat treatment apparatus according to the present invention supports a vibration plate portion for ultrasonically levitating the substrate, an ultrasonic wave generating portion for applying ultrasonic vibration to the vibration plate portion, and an end portion of the substrate. A plurality of levitation conveyance units having a conveyance unit that conveys the substrate in a direction perpendicular to the substrate levitation direction, and each of the levitation conveyance units sequentially heats and conveys the substrate while ultrasonically levitating the substrate. A levitation conveyance heat treatment apparatus, wherein the levitation conveyance unit includes a heating region including a heater unit that heats a diaphragm portion of the levitation conveyance unit, and a cooling region in which the levitation conveyance unit does not include the heater unit. It is characterized by being.

  According to the levitation transfer heat treatment apparatus, the substrate heated in the heating region can be cooled in a short time by the cooling region. Specifically, forced convection is generated in the gas between the substrate and the vibration plate portion by the levitation conveyance unit ultrasonically levitating the substrate in the heating region and the cooling region. Heat transfer is performed between the substrate and the vibration plate portion via the forced convection gas, but the forced convection is generated by ultrasonic vibration, so that high-speed heat transfer is possible. As a result, the substrate can be cooled in a short time in the cooling region. In addition, since the heating region and the cooling region are adjacent in the levitation transfer heat treatment apparatus, it is possible to shorten the time for transporting the substrate from the heating region to the cooling region as compared with the case where the cooling region is provided separately. In addition, since the cooling of the substrate starts from the portion that has approached the cooling region even during the transportation, time loss due to the transportation of the substrate can be reduced.

  In addition, the cooling region may be located on the most downstream side with respect to the substrate transport.

  By doing so, the heated substrate can be finally cooled sufficiently in the cooling region and delivered to the next process.

  According to the levitation transfer heat treatment apparatus of the present invention, the heated substrate can be cooled in a short time.

It is the schematic of the levitation conveyance heat processing apparatus in one Embodiment of this invention. It is a perspective view of the heating area | region in this embodiment. It is a side view of the heating area | region in this embodiment. It is a perspective view of the cooling area | region in this embodiment. It is the schematic which shows the cooling form of the board | substrate in this invention. It is a graph which shows the example of the cooling performance of the cooling area | region in this embodiment. It is the schematic which shows the temperature change of the board | substrate by the levitation conveyance heat processing apparatus in this embodiment. It is the schematic which shows the temperature change of the board | substrate by the conventional levitation conveyance heat processing apparatus and this levitation conveyance heat processing apparatus.

  Embodiments according to the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic view of a levitation transfer heat treatment apparatus according to an embodiment of the present invention.

  The levitation transfer heat treatment apparatus 1 has a heating region 2 and a cooling region 3 and heats and cools the substrate W while the substrate W is floated by ultrasonic vibration.

  The heating area 2 is an area for heating the substrate W. The heating region 2 is provided with a plurality of later-described diaphragm portions 4 having different set temperatures, so that the substrate W is not only dried but also baked.

  The cooling region 3 is located on the most downstream side with respect to the transport of the substrate W, and prepares to deliver it to a downstream processing apparatus by cooling the substrate W heated in the heating region 2 to near room temperature.

  Further, the heating area 2 and the cooling area 3 have a transfer section 7 which will be described later, and after the substrate W has floated on the respective vibrating plate sections 4 of the heating area 2 and the cooling area 3 for a predetermined time, the transfer section 7 Is transferred to the adjacent diaphragm 4. By repeating this, the substrate W is heated and cooled while being transferred in the levitation transfer heat treatment apparatus 1. In the following description, the direction in which the substrate W is transported is the Y-axis direction, the direction orthogonal to the Y-axis direction on the horizontal plane is the X-axis direction, and the direction orthogonal to both the X-axis and Y-axis directions is the Z-axis direction. The explanation will proceed as follows.

  Schematic diagrams of the heating region 2 in this embodiment are shown in FIGS.

  The heating region 2 includes a vibration plate portion 4, a heater portion 5, an ultrasonic wave generation portion 6, and a conveyance portion 7. The vibration plate portion 4 is ultrasonically vibrated by the ultrasonic wave generation portion 6, and the radiation pressure due to the vibration is obtained. As a result, the substrate W on the diaphragm 4 is levitated. Further, the diaphragm portion 4 is heated by the heater portion 5. Further, the substrate W is carried into the diaphragm unit 4 by the transport unit 7, unloaded from the diaphragm unit 4, and transported on the diaphragm unit 4.

  In the present description, the diaphragm 4, the ultrasonic wave generator 6, and the transport unit 7 are collectively referred to as a floating transport unit.

  The diaphragm portion 4 has a plurality of diaphragms 21. The vibration plate 21 is a metal plate made of aluminum (made of aluminum alloy) and having a rectangular plate shape in the present embodiment, and when they are continuously arranged in the substrate transport direction (Y-axis direction), A diaphragm portion 4 is formed.

  Since the diaphragm portion 4 is heated by the heater portion 5 as described above, the substrate W levitated on the diaphragm portion 4 can be heated by radiation heating.

  Here, the dimension in the X-axis direction and the dimension in the Y-axis direction of the diaphragm portion 4 are set larger than the dimensions in the X-axis direction and the Y-axis direction of the substrate W when the substrate W is placed on the diaphragm 21. Has been. Thus, when the substrate W is heated while floating on the diaphragm portion 4, the entire surface of the substrate W exists on the diaphragm portion 4 without the portion where the substrate W protrudes from the diaphragm portion 4. Therefore, the substrate W can be uniformly heated by the diaphragm 4 heated by the heater 5.

  The heater unit 5 is located on the back surface 9 side of the surface 8 on which the substrate W of the vibration plate unit 4 is levitated, and has a plurality of heater units 31 and spacers 32. By arranging the heater units 31 in the X-axis direction and the Y-axis direction, one heater assembly 33 is formed. The spacer 32 is installed in a part of the heater units 31 to support the diaphragm 21, and the diaphragm portion 4 and the heater assembly 33 are separated from each other with a predetermined interval by the spacer 32.

  In this embodiment, the heater unit 31 is a plate heater configured by inserting a cartridge heater or a sheathed heater into a rectangular plate-like aluminum plate, and these are arranged without gaps in the X-axis direction and the Y-axis direction. Here, a mica heater may be used instead of the plate heater.

  Here, the dimension of the heater assembly 33 in the X-axis direction is larger than the dimension of the diaphragm portion 4 in the X-axis direction, and the dimension of the heater assembly 33 in the Y-axis direction is the Y-axis of the diaphragm portion 4. It is equal to or greater than the direction. When the heater assembly 33 is viewed from the vibration plate portion 4 along the Z-axis direction, the region of the vibration plate portion 4 is disposed within the region of the heater assembly 33. As a result, the heater assembly 33 can simultaneously heat the entire surface of the diaphragm 4 and can heat the entire diaphragm 4 to a uniform temperature. Each heater unit 31 forming the heater assembly 33 may be smaller in dimensions in the X-axis direction and the Y-axis direction than the diaphragm 21. Alternatively, a method may be employed in which the diaphragm portion 4 is heated using only one heater unit 31 that does not take the form of an aggregate and has dimensions in the X-axis direction and the Y-axis direction that are larger than those of the diaphragm portion 4.

  The spacer 32 is, for example, a resin-made small-diameter block. In the present embodiment, the spacer 32 provides a space of 1 mm between the vibration plate portion 4 and the heater assembly 33. By separating the diaphragm portion 4 and the heater assembly 33 in this way, heating to the diaphragm portion 4 by the heater assembly 33 is not direct heating but heat transfer by radiant heating and convection, which is compared with direct heating. Thus, it becomes easy to make the temperature of the entire diaphragm portion 4 uniform.

  Further, when the vibration plate portion 4 and the heater assembly 33 are in contact with each other, the heater assembly 33 may hinder the vibration of the vibration plate portion 4 due to a difference in vibration characteristics such as the natural frequency of both. However, by separating the two, the diaphragm 4 can vibrate as set without being disturbed by the heater assembly 33.

  Here, the spacer 32 is desirably disposed on the heater unit 31 so as to support the diaphragm 21 at a position corresponding to a vibration node of the diaphragm 21. Thereby, since the vibration received by the spacer 32 from the diaphragm 21 can be minimized, the spacer 32 can be prevented from being worn by interference with the diaphragm 21.

  The ultrasonic generator 6 has an ultrasonic transducer 41 and a horn 42. The ultrasonic transducer 41 is on the same side as the heater unit 31 with respect to the diaphragm 21 when viewed from the Z-axis direction, and is disposed at a position farther from the diaphragm 21 than the heater unit 31. A horn 42 is connected to the ultrasonic transducer 41, and the horn 42 penetrates the heater unit 31 and is in contact with the diaphragm 21.

  The ultrasonic transducer 41 excites an object based on an oscillation signal from an oscillator (not shown). For example, there is a Langevin type transducer having an electrode and a piezoelectric element. In the Langevin type vibrator, when a driving voltage is applied to an electrode by an oscillator, the piezoelectric element vibrates and oscillates with a predetermined amplitude and frequency. The vibration of the ultrasonic transducer 41 oscillated in this way propagates to the diaphragm 21 that is the object via the horn 42, and vibrates the diaphragm 21. When the diaphragm 21 vibrates, a radiated sound pressure is generated from the diaphragm 21, and an upward force is applied to the substrate W on the diaphragm 21 by the radiated sound pressure. As a result, the substrate W can be held in a state where it floats above the diaphragm 21 by a predetermined flying height.

  In addition, the amplitude and frequency of the vibration of the ultrasonic transducer 41 can be adjusted by controlling the drive voltage applied from the oscillator, thereby adjusting the flying height of the substrate W floating on the vibration plate 21. Is possible. The flying height of the substrate W is about 0.1 mm in this embodiment.

  The horn 42 has a shape in which a cylinder or a plurality of cylinders are connected, one end is connected to the ultrasonic transducer 41, the other end is in contact with the vibration plate 21, and vibration of the ultrasonic transducer 41 is emitted. The amplitude is amplified or attenuated and propagated to the diaphragm 21. Further, since the horn 42 is disposed so as to penetrate the heater unit 31, the heater unit 31 is provided with a through hole or notch at a position where the horn 42 is disposed to avoid interference with the horn 42.

  In addition, the horn 42 also serves to separate the ultrasonic transducer 41 from the heater assembly 33 by being installed between the ultrasonic transducer 41 and the diaphragm 21. Since the ultrasonic transducer 41 is vulnerable to heat and abnormalities such as damage to the piezoelectric element occur when heated, the horn 42 is used to prevent the heat from the heater assembly 33 from being transmitted to the ultrasonic transducer 41. The sound wave oscillator 41 is kept away from the heater assembly 33.

  Here, in the present embodiment, considering that the conveyance of the substrate W is not hindered, the ultrasonic transducer 41 is viewed from the Z-axis direction on the same side as the heater unit 31 with respect to the diaphragm 21, that is, the substrate W. Although it is in contact with the diaphragm 21 on the opposite side, the contact may be made on the same side as the substrate W. Even if the ultrasonic transducer 41 is brought into contact with the same side as the substrate W, it is possible to obtain the effect of causing the substrate W to oscillate and float as in the case where the ultrasonic transducer 41 is brought into contact with the opposite side of the substrate W as in this embodiment. is there.

  The transport unit 7 includes a hand 51 and an advance / retreat mechanism 52. The hand 51 has, for example, an L-shaped block, and supports the two sides of the substrate W in contact with the corners of the substrate W. Two hands 51 are provided in the diagonal direction of the substrate W with respect to the support of one substrate W so that the diagonal of the substrate W can be positioned and supported. The advancing / retracting mechanism 52 is a linear motion mechanism such as an air cylinder. The hand 51 is attached to move the respective hands 51 when the substrate W is supported and when the support is released. By this advance / retreat mechanism 52, the hand 51 approaches the substrate W when the substrate W is supported, and retracts from the substrate W when the support is released. Here, in the state where the hand 51 is retracted, the substrate W is in a state where the restraints in the X-axis direction and the Y-axis direction are released. Therefore, when the hand 51 approaches next, the position of the substrate W is shifted. There is a possibility that the substrate W and the hand 51 are damaged by colliding with the hand 51. In this case, a pin that moves up and down is provided on the vibration plate portion 4, and when the hand 51 is retracted and the substrate W is floating at a predetermined position on the vibration plate portion 4, the pin is raised to restrain the position of the substrate W. When the substrate W is transported on the diaphragm 4, the pins are preferably lowered so as not to disturb the transport operation.

  The advance / retreat mechanism 52 is connected to a travel axis in the Y-axis direction (not shown). When the hand 51 approaches the corner of the substrate W and supports the substrate W, the hand 51 and the advancing / retracting mechanism 52 move in the Y-axis direction by this traveling axis, whereby the substrate W is transported in the Y-axis direction. Is done.

  Next, the attachment position of the ultrasonic wave generation unit 6 to the diaphragm unit 4 will be described with reference to FIGS. 2 and 3.

  As described above, in order to propagate the vibration from the ultrasonic transducer 41 to the diaphragm 21, the horn 42 is in contact with the diaphragm 21, and the heater unit 31 penetrates at the position where the horn 42 is disposed. There is a hole or notch. For this reason, at the location where the horn 42 of the diaphragm 21 is in contact and in the vicinity thereof, compared to other locations, it is less susceptible to heating from the heater unit 31 and the temperature is lowered. The same applies to the surface on the side where the substrate W is levitated, and the temperature is lowered at and near the position where the horn 42 is in contact with the back surface. If the substrate W is heated at such a location, the substrate W cannot be sufficiently heated as compared with other locations, and thus there is a possibility of causing unevenness of drying on the substrate W.

  Therefore, in the present embodiment, the substrate W is not heated in the above-described places to prevent drying unevenness. Specifically, the region R1 that floats the substrate W of the vibration plate portion 4 and the region on the back side of the diaphragm portion 4 shown in FIG. 2 and FIG. The diaphragm 21 is in contact with the horn 42 outside the region where W is heated.

  Next, FIG. 4 shows a schematic diagram of the cooling region 3 in the present embodiment.

  The cooling region 3 includes a vibration plate portion 10, an ultrasonic wave generation portion 11, and a conveyance portion 12. That is, it has the same configuration as the above-described levitation conveyance unit, and has the same configuration as that of the heating region 2 except that it does not have a heater section.

  The vibration plate unit 10 is ultrasonically vibrated by the ultrasonic wave generation unit 11 in the same manner as the vibration plate unit 4 in the heating region 2, and the substrate W on the vibration plate unit 4 is floated by the radiation pressure due to the vibration. Further, the substrate W is carried into the diaphragm 10 by the transport unit 12, unloaded from the diaphragm 10, and transported on the diaphragm 10.

  Note that in the heating region 2, as described above, the attachment position of the ultrasonic generator 6 is mentioned in order to prevent the occurrence of uneven drying of the substrate W, but the coating liquid on the substrate W that has been completely dried and baked is newly generated from there. In that case, in the cooling region 3, the ultrasonic wave generation unit 11 may be attached to a region corresponding to the back side of the region where the substrate W of the diaphragm unit 10 is levitated.

  Next, the cooling mode of the substrate in the present invention is shown in FIG.

  When the substrate W floats ultrasonically on the diaphragm 10, the gas existing between the surface 13 of the diaphragm 10 that floats the substrate W and the substrate W has an external force called ultrasonic vibration of the diaphragm 10. Will be added. By this external force, the gas is convected between the diaphragm 10 and the substrate W as shown by the arrows. That is, forced convection occurs.

  When the forced convection gas comes into contact with the substrate W and the vibration plate portion 10, heat transfer occurs between the gas and the substrate W and between the gas W and the vibration plate portion 10.

  Therefore, when the substrate W heated by the heating region 2 is transported onto the vibration plate portion 10 in the cooling region 3, and the vibration plate portion 10 causes the substrate W to ultrasonically levitate, the substrate W is moved by the forced convection. To be cooled.

  Note that forced convection occurs when an external force is applied to the gas. For example, even when air is ejected from the air levitation unit to float the substrate, the gas between the air levitation unit and the substrate is forced convection. Accordingly, even when the heated substrate is levitated by the air levitation unit, heat transfer is performed between the forced convection gas and the substrate, and the substrate W is cooled. On the other hand, when the vibration plate unit 10 causes the substrate W to be ultrasonically oscillated, forced convection occurs when the vibration plate unit 10 vibrates at a very high frequency of several tens of kHz. Much faster than with the unit. Accordingly, the heat transfer speed is much higher than that of the air levitation unit, and the substrate W can be cooled in a short time.

  Further, as described above, the cooling region 3 is provided on the downstream side of the heating region 2, and the substrate W can be directly received from the heating region 2 by the transport unit 7 in the heating region 2 or the transport unit 12 in the cooling region 3. it can. Thereby, as in the conventional example shown in FIG. 8, the transfer robot 93 receives the substrate W from the floating transfer heat treatment apparatus 90, and the transfer robot 93 places the substrate W on the cooling unit 92 provided separately. It is possible to shorten the conveyance time to the cooling area | region 3 compared with. Further, even during the transfer, since the cooling of the substrate W starts from the portion approaching the cooling region 3, a time loss due to the transfer of the substrate W can be reduced.

  An example of the cooling performance of the cooling region 3 is shown in the graph of FIG.

  In the graph of FIG. 6, the solid line represents the temperature change of the substrate W when the substrate W is cooled by the cooling region 3 of the present embodiment, and the broken line represents the substrate W levitated by the air levitation unit. . Here, the temperature of the substrate W before cooling was about 110 ° C., the temperature of the diaphragm 10 before the substrate W was transported, and the temperature of the air ejected from the air levitation unit was about 20 ° C.

  As a result, as shown in the figure, the cooling effect by the ultrasonic vibration levitation is larger than the cooling effect at the time of air levitation. For example, the time required for cooling the temperature of the substrate W to a predetermined temperature such as near room temperature is reduced. It was possible to make it shorter than when the air flew.

  Next, the temperature change of the substrate by the levitation transfer heat treatment apparatus 1 in the present embodiment is shown in FIG.

  As described above, the cooling region 3 is adjacent to the downstream side of the heating region 2, and the transport time from the heating region 2 to the cooling region 3 is short. Therefore, immediately after the drying and baking of the substrate W in the heating region 2, the cooling of the substrate W by the cooling region 3 can be started immediately.

  And as shown in FIG. 6, the cooling performance by the cooling area | region 3 of this embodiment using the forced convection by an ultrasonic vibration is high, and can cool the board | substrate W in a short time.

  Therefore, the transfer time of the substrate W from the heating region 2 (heating region 91 in the conventional example of FIG. 8) to the cooling region 3 (cooling unit 92 in the conventional example of FIG. 8) and the placement time of the substrate W on the cooling region. Is the time required for cooling the substrate W, the levitation transfer heat treatment apparatus 1 of the present embodiment can reduce the time required for cooling the substrate W as compared with the prior art.

  Thus, the substrate W sufficiently cooled in the cooling region 3 downstream of the levitation transfer heat treatment apparatus 1 can be delivered to the next process at a substrate temperature close to room temperature.

  FIG. 5 illustrates the cooling mode of the substrate W by the cooling region 3, and it has been described that the substrate W is cooled by the forced convection of the gas between the vibration plate portion 10 and the substrate W. Even in the same case, forced convection of gas is generated between the diaphragm 4 and the substrate W shown in FIG. 3 due to ultrasonic vibration of the diaphragm 4, and the gas between the substrate W and the diaphragm 4 is interposed. The substrate W is heated by the heat transfer. Further, in this case, the substrate W is also heated by the radiant heat from the vibration plate portion 4 heated to the heater portion 5 to the substrate W.

  Further, in the heating region 2, gas is forcibly convected between the diaphragm 4 and the heater 5 by the ultrasonic vibration of the diaphragm 4, and heat transfer by the forced convection and the heater 5 to the diaphragm 4 are performed. The heater unit 5 heats the diaphragm unit 4 by the radiant heat.

  According to the levitation transfer heat treatment apparatus described above, the heated substrate can be cooled in a short time.

  In this embodiment, the cooling region 3 is disposed only on the most downstream side of the levitation transfer heat treatment apparatus 1, and the substrate W heated in the heating region 2 is sufficiently cooled to transfer the substrate W to the downstream processing apparatus. However, the cooling region 3 is not limited to the most downstream side, and the cooling region 3 may be provided in the middle of the heating region 2. That is, for example, the heating region 2 and the cooling region 3 may be provided so as to become the heating region 2, the cooling region 3, the heating region 2, and the cooling region 3 in order from the upstream side.

DESCRIPTION OF SYMBOLS 1 Levitation conveyance heat processing apparatus 2 Heating area 3 Cooling area 4 Vibrating plate part 5 Heater part 6 Ultrasonic wave generation part 7 Conveyance part 8 The surface which floats a board | substrate 9 The back surface of the surface which floats a board | substrate 10 Vibrating board part 11 Ultrasonic wave generation part 12 Conveying section 13 Surface for floating substrate 21 Diaphragm 31 Heater unit 32 Spacer 33 Heater assembly 41 Ultrasonic vibrator 42 Horn 51 Hand 52 Advance / retreat mechanism 90 Levitation conveyance heat treatment device 91 Heating area 92 Cooling unit W substrate

Claims (2)

A vibrating plate part for ultrasonically levitating the substrate;
An ultrasonic generator for applying ultrasonic vibration to the diaphragm,
A transport unit that supports the edge of the substrate and transports the substrate in a direction perpendicular to the floating direction of the substrate;
A plurality of levitating conveyance units having the above, each levitating conveyance unit heat-treating and conveying the substrate in order while ultrasonically levitating the substrate,
A heating region provided with a heater unit for heating the diaphragm unit of the levitation conveyance unit;
A cooling region in which the levitation transport unit does not include the heater unit;
A levitation conveyance heat treatment apparatus characterized by comprising:   The levitation conveyance heat treatment apparatus according to claim 1, wherein the cooling region is located on the most downstream side with respect to the conveyance of the substrate.

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