JP2010169308A - Dryer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dryer capable of drying a solution on a substrate, making the shape of a luminous layer after drying uniform, and being manufactured inexpensively. <P>SOLUTION: The substrate P to which the solution is applied is dried in a chamber 100. Within the chamber 100, a porous adsorbing member 102 for adsorbing a solvent in the solution evaporated during drying is arranged to oppose to the substrate P. An opening area ratio of the central part of the adsorbing member 102 is set larger than that of the outer peripheral part of the adsorbing member 102. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a drying apparatus for evaporating a solvent in a solution applied on a substrate and drying, and more particularly to a drying apparatus applied to a process of manufacturing a functional element by a wet process.

  Currently, various light-emitting elements are used. Among them, organic EL elements having features such as light weight, low power consumption, high image quality, and wide viewing angle are attracting attention. An organic EL element has a structure in which an organic thin film containing at least a light emitting material is sandwiched between a cathode and an anode. Depending on the type of the light emitting material, a low molecular type using a low molecular material and a polymer using a polymer material are used. Broadly divided into types.

  In the case of low molecular type elements, an organic thin film is formed mainly by a dry process such as a vacuum deposition method. In the case of high molecular type elements, it is mainly dissolved or dispersed in a solvent before spin coating or inkjet method. An organic thin film is formed by a wet process.

  The vacuum deposition method used in the manufacture of a low molecular device is a high vacuum process that requires a large facility, and thus has problems such as high manufacturing cost and low productivity.

  On the other hand, in the production of polymer-type devices, the film is formed by spin coating or ink-jet method in the atmosphere, so the equipment cost is lower and the screen can be enlarged compared to the production of low-molecular devices. Has the advantage.

  In general, in a wet process such as a spin coating method or an ink jet method, a film in which a polymer material is dissolved in a solvent is applied to a predetermined position of an element substrate, and the solvent in the solution is dried. Usually, a solution in which a polymer material is dissolved is uniformly applied on the substrate. However, although the required amount of solution is uniformly applied to the substrate, the formed film has poor uniformity.

  The reason will be described below.

  In an organic EL element, there are many pixels to which a solution is applied around the pixel at the center of the substrate, but there is a region around which the solution is not applied around the pixel at the outer periphery of the substrate. For this reason, when the solvent is dried, the vapor concentration of the solvent on the substrate is higher in the central portion of the substrate than in the outer peripheral portion.

  In the first place, the film shape after drying is determined by the flow of the solution during drying, and the flow of the solution is determined by the drying speed. However, as described above, since the vapor concentration of the solvent is higher in the central portion of the substrate than in the outer peripheral portion, the drying speed of the solution is slower in the central portion. Therefore, it is considered that there is a difference in the shape of the organic layer between the central part and the outer peripheral part after drying.

In Patent Document 1, the solvent is first applied to the effective region, the outer periphery of the effective region, or the region other than the dots in the pixel, and then the ink is applied to reduce the occurrence of the difference in the vapor concentration of the solvent in the effective region. In which the drying rate of the solvent is made uniform and the difference in the shape of the functional layer after drying is reduced. Here, the effective area is an area for displaying an image on the display.
JP 2004-31070 A

  However, the technique described in Patent Document 1 requires a large amount of materials, equipment, and man-hours necessary for forming a functional layer by narrowing the effective area in the substrate and applying a solvent outside the effective area. This increases the manufacturing cost.

  In view of the conventional technology, an object of the present invention is to provide a drying apparatus capable of making the shape of a layer film on a substrate after drying uniform and manufacturing an organic EL element and the like at a low cost.

  In order to solve the problems and achieve the object, the invention according to claim 1 is a drying apparatus configured to evaporate and absorb a solvent in a solution applied on a substrate, and the substrate is accommodated in the drying device. And a porous adsorbing member that is placed opposite to the substrate and adsorbs the solvent in the chamber, and the opening ratio of the central portion of the porous adsorbing member is determined from the opening ratio of the outer peripheral portion. Is also set to be large.

  According to the present drying apparatus, when the solution applied to the substrate dries, the evaporated solvent is exhausted while being adsorbed by the porous adsorbing member. That is, the porous adsorbing member has air permeability, and most of the solvent is temporarily adsorbed to the porous adsorbing member.

  The central portion of the porous adsorbing member that faces the central portion of the substrate has a larger opening ratio of the porous adsorbing member than the outer peripheral portion of the porous adsorbing member. Less than This makes it possible to correct the difference in vapor concentration that occurs when there is no porous adsorbing member, that is, the vapor concentration on the central portion of the substrate is high and the vapor concentration on the peripheral portion of the substrate is low.

  As a result, the vapor concentration on the substrate becomes uniform, and variations in the drying rate between the central portion and the outer peripheral portion of the substrate can be reduced. That is, the film shape difference after drying can be reduced. In addition, since it is not necessary to apply a solvent outside the effective area, it is possible to reduce the materials and man-hours that are the problems of the prior art.

  According to a second aspect of the present invention, in the drying apparatus according to the first aspect, the porous adsorbing member is an inorganic porous material, and the adsorbing member can be regenerated by heating.

  The invention according to claim 3 is characterized in that, in the drying apparatus according to claim 1, an exhaust port is provided at an upper portion of the chamber, and an exhaust unit for exhausting the atmosphere of the chamber from the exhaust port and depressurizing is installed. By providing the exhaust part, the efficiency of drying the solution can be increased.

  According to a fourth aspect of the present invention, in the drying apparatus according to the third aspect, the exhaust port is disposed so as to face the central portion of the substrate, and the exhaust port is opposed to the central portion of the substrate. The evaporation rate of the part can be increased.

  The present invention can make the shape of the light emitting layer after drying uniform by setting the opening ratio of the central part in the porous adsorbing member that adsorbs the solvent in the drying step larger than the opening ratio of the outer peripheral part, In addition, the practical effect of reducing the manufacturing cost is significant.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, the outline | summary is demonstrated about the method of manufacturing a functional element using the drying apparatus which concerns on this invention.

  The manufacturing method of a functional element has a functional layer formation process. In the above step, a solution obtained by dissolving a functional organic material such as a fluorene polymer material in a solvent such as toluene or cyclohexylbenzene is applied onto a substrate using a wet process such as a spin coating method or an ink jet method. To do. The amount of solution to be applied is determined by the thickness of the organic functional layer to be formed, the shape of the application part, and the concentration of the polymer material in the solution.

  Next, an organic functional layer is formed by performing a drying process. In this drying step, the solvent contained in the solution evaporates, and an organic functional layer is obtained.

  The drying method in the present embodiment has at least one of a step of controlling the temperature of the functional element and a step of controlling the pressure of the chamber, and a step of adsorbing the evaporated solvent, and a temperature for realizing it. It has the mounting base which can perform control, the apparatus which adjusts a pressure, and the porous adsorption | suction member which adsorb | sucks a solvent.

  In the present drying apparatus, when the solution applied to the substrate dries, the evaporated solvent is exhausted while being adsorbed by the porous adsorption member. That is, the porous adsorbing member has air permeability, and most of the solvent is temporarily adsorbed to the adsorbing member.

  In addition, as the adsorbing member, those having different opening ratios at the central portion of the substrate and the outer peripheral portion of the substrate are used. The central portion of the adsorption member that faces the central portion of the substrate has a larger opening ratio of the adsorption member than the outer peripheral portion of the adsorption member, so the adsorption amount at the central portion is smaller than the adsorption amount at the outer peripheral portion. This makes it possible to correct the difference in vapor concentration that occurs when there is no adsorbing member, that is, the vapor concentration on the central portion of the substrate is high and the vapor concentration on the peripheral portion of the substrate is low.

  As a result, the vapor concentration on the substrate becomes uniform, and variations in the drying rate between the central portion and the outer peripheral portion of the substrate can be reduced. That is, the film shape difference after drying can be reduced. In addition, since it is not necessary to apply a solvent outside the effective area, it is possible to reduce the materials and man-hours that are problems of the prior art.

  Further, the porous adsorbing member adsorbing the solvent can be removed by using a vacuum drying apparatus to remove the adsorbed solvent and can be used again.

  Hereinafter, a drying device according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view showing a schematic configuration of a drying apparatus according to an embodiment of the present invention. The drying apparatus 1 includes a chamber 100 that accommodates a substrate P and forms a process chamber that can be hermetically sealed. Yes. The chamber 100 includes a mounting table 101 on which the substrate P is mounted, and a porous adsorption member 102 that is installed facing the upper side of the mounting table 101.

  As the adsorption member 102, for example, a member made of an inorganic material such as a metal such as nickel or a ceramic such as zirconia is used. By making the adsorbing member 102 porous, it can be regenerated by heating.

  Further, the suction member 102 is set so that the aperture ratio is smaller in the outer peripheral portion than in the central portion. The opening ratio of the center part with respect to the opening ratio of the outer peripheral part of the adsorbing member 102 is evaluated by the gas adsorption BET method, and is preferably 2 to 20 times. The suction member 102 is provided with a lifting mechanism 110 that moves the suction member 102 up and down.

  The elevating mechanism 110 includes a drive unit 111 that raises and lowers the adsorption member 102 with a motor or the like, and a control unit 112 that controls the drive unit 111. Accordingly, the suction member 102 can move in the vertical direction, and the suction member 102 is integrated with the mounting table 101 by lowering the suction member 102.

  An exhaust pipe 120 serving as an exhaust unit for exhausting the atmosphere in the processing chamber is provided in the central portion above the adsorption member 102. The exhaust pipe 120 is connected to a suction pump 121 that sucks the atmosphere in the processing chamber at a predetermined pressure. The suction force of the suction pump 121 is controlled by the pump control unit 122. The inside of the chamber 100 can be evacuated by operating the suction pump 121 and exhausting and sucking the atmosphere in the chamber 100 from the exhaust pipe 120.

  A gas supply unit 123 that supplies gas (for example, nitrogen gas) into the chamber 100 through the exhaust pipe 120 is connected to the exhaust pipe 120. As a result, a gas can be supplied into the chamber 100 after the reduced-pressure vacuum treatment to recover from the vacuum state, or the atmosphere in the chamber 100 can be purged.

  Exhaust of the atmosphere in the chamber 100 by the exhaust pipe 120 is performed via the adsorption member 102. The porous adsorbing member 102 can adsorb the solvent that evaporates during drying.

  Next, a drying method using the present drying apparatus will be described.

First, the substrate P is mounted on the mounting table 101, and the suction member 102 is lowered from the upper surface of the substrate P to a position of 0.5 to 10 mm. Thereafter, the atmosphere in the chamber 100 is evacuated from atmospheric pressure to 104 to 10 ⁻² Pa over 0.5 to 60 minutes, and the film shape is determined.

  According to the present drying apparatus 1, when the solution applied to the substrate P dries, the evaporated solvent is exhausted while being adsorbed by the porous adsorption member 102. That is, the porous adsorption member 102 has air permeability, and most of the solvent is temporarily adsorbed by the adsorption member.

  The central portion 102 a of the suction member 102 that faces the central portion of the substrate P has a larger aperture ratio than the outer peripheral portion 102 b of the suction member 102. For this reason, the amount of adsorption of the solvent at the central portion 102a of the adsorption member 102 is smaller than the amount of adsorption at the outer peripheral portion.

  This makes it possible to correct the difference in vapor concentration that occurs when there is no adsorbing member, that is, the vapor concentration on the central portion of the substrate is high and the vapor concentration on the peripheral portion of the substrate is low.

  As a result, the vapor concentration on the substrate P becomes uniform, and variations in the drying rate between the central portion and the outer peripheral portion of the substrate P can be reduced. That is, the film shape difference after drying can be reduced. In addition, since it is not necessary to apply the solvent outside the effective area, it is possible to reduce the materials and man-hours that are conventional problems.

  After the film shape is formed, the adsorption member 102 is raised to a position sufficiently separated from the substrate P in order to completely remove the residual solvent. This distance is preferably 100 to 200 mm, and is preferably kept at a distance that prevents the solvent detached from the adsorbing member 102 from being re-adsorbed to the substrate P. At this time, simultaneously with the removal of the solvent in the substrate P, the solvent still adsorbed on the adsorption member 102 can be removed, and the adsorption member 102 can be used again.

  Note that a mounting table having a temperature control mechanism with a temperature range of 10 to 200 ° C. may be used as the mounting table 101. By using a mounting table having this temperature control mechanism, the drying speed in the substrate surface can be made more uniform.

  In the first embodiment, the drying under reduced pressure has been described as an example. However, the present invention is not limited to this, and can be applied to heat drying in a normal pressure or pressurized atmosphere.

  Next, an embodiment adopting multi-chamfering will be described. Multi-chamfering is a method in which a plurality of effective regions 310 are formed on a single substrate P as shown in FIG. 2A is a plan view of the adsorption member, FIG. 2B is a plan view of the substrate, and FIG. 2C is a cross-sectional view showing an assembled state of the adsorption member and the substrate.

  In FIG. 2, when a solution is applied to the effective area 310 of the substrate P adopting the multi-chamfering method and dried, the porous adsorption member 300 used is the center of each effective area of the substrate P as shown in FIG. The aperture ratio of the adsorbing member region 301 facing the portion 311 is the largest, then the aperture ratio of the adsorbing member region 302 facing the effective region outer peripheral portion 312 is large, and the region 313 between the effective regions on the substrate is opposed. The aperture ratio is set so as to decrease in the order of the suction member region 303 and the suction member region 304 facing the substrate outer peripheral portion 314.

  By using the adsorbing member 300, when the solution applied to each effective area of the substrate P dries, the evaporated solvent is exhausted while adsorbed by the porous adsorbing member 300. That is, as in the first embodiment, the porous adsorbing member has air permeability, and most of the solvent is temporarily adsorbed onto the adsorbing member.

  A suction member region 301 facing each effective region central portion 311 of the substrate P, a suction member region 302 facing each effective region outer peripheral portion 312 of the substrate P, and a suction member facing the region 313 between each effective region of the substrate P Since the opening ratio of the suction member 300 decreases in the order of the region 303 and the suction member region 304 facing the outer peripheral portion 314 of the substrate P, the suction amount also increases in that order.

  As a result, it is possible to correct the difference in vapor concentration that occurs when there is no adsorption member, that is, the vapor concentration on the center of each effective region of the substrate is high and the vapor concentration on the substrate outer periphery is low.

  As a result, the vapor concentration on the substrate P becomes uniform, and variations in the drying rate between the central portion and the outer peripheral portion of the substrate P can be reduced. That is, the film shape difference after drying can be reduced. In addition, since it is not necessary to apply the solvent outside the effective area, it is possible to reduce the materials and man-hours that are conventional problems.

  FIG. 3 illustrates a method for reusing an adsorbing member that has adsorbed a solvent.

  As shown in FIG. 3, the 1st drying apparatus 1 and the 2nd drying apparatus 2 which are the same structures as the drying apparatus shown in FIG. 1 are provided side by side. In this example, there is an adsorbing member 102 that adsorbs a solvent to the first drying apparatus 1. The solvent adsorbed on the adsorption member 102 is removed by the second drying device 2.

  The second drying apparatus 2 includes a chamber 200 that is a processing chamber that can be hermetically sealed. The chamber 200 includes a mounting table 201 on which the adsorption member 202 is mounted, and an exhaust unit, which will be described later, provided above the mounting table 201.

  An exhaust pipe 220 serving as an exhaust unit for exhausting the atmosphere in the chamber 200 is provided at the upper center portion of the mounting table 201. The exhaust pipe 220 is connected to a suction pump 221 that sucks the atmosphere in the chamber 200 at a predetermined pressure, and the suction force of the suction pump 221 is controlled by the pump control unit 222. When the suction pump 221 is activated and the atmosphere in the chamber 200 is exhausted and sucked from the exhaust pipe 220, the inside of the chamber 200 can be evacuated. In the figure, reference numeral 223 denotes a gas supply unit having the same function as the gas supply unit 123 of FIG.

  By exhausting the atmosphere in the chamber 200 with the exhaust pipe 220, the solvent adsorbed on the adsorption member 202 can be removed.

  Further, the mounting table 201 is provided with a temperature control unit capable of performing temperature control. By providing the temperature control unit, evaporation of the solvent can be promoted, and the solvent can be completely removed earlier than in the case of only exhaust.

  Further, as described with reference to FIG. 1, since the inorganic porous material is also used for the adsorbing member 202 of the second drying device 2, it has heat resistance and the adsorbing member 202 is deformed and deteriorated by heating. Hard to happen.

  Next, the drying method of the adsorption member using this drying apparatus will be described.

  The adsorption member 102 that has adsorbed the solvent in the first drying device 1 is moved to the second drying device 2 after the adsorption process is completed, and is replaced with the adsorption member 202 of the second drying device 2. In the second drying device 2, the temperature is further applied to the adsorption member 102 at a pressure lower than that of the first drying device 1 to completely remove the solvent. By heating while exhausting in this way, the solvent can be completely removed in a short time. By doing so, the adsorbing member can be used again and again.

  By completely removing the solvent adsorbed on the adsorbing member by the drying method, the next substrate coated with the solution can be uniformly dried.

  When removing the solvent adsorbed on the adsorbing member, the timing of solvent removal completion may be managed by pressure change. In addition, although it was set as the content which replaces an adsorption | suction member in the above-mentioned, you may use one adsorption | suction member and transfer an adsorption | suction member to the drying apparatus 2 after film | membrane shape determination.

  In this manner, the adsorption member 102 was applied to the substrate P by removing the solvent adsorbed on the adsorption member using the second drying device 2 different from the first drying device 1 that dries the substrate P. As soon as the solution is dry, it can proceed to the next process. As a result, the drying time required per substrate can be shortened.

  INDUSTRIAL APPLICABILITY The present invention is effective for use in manufacturing a device that requires uniformity of a functional film such as an organic semiconductor, in particular, manufacturing an organic EL element.

1 is a partial sectional view showing a schematic configuration of a drying apparatus according to an embodiment of the present invention. The principal part of this Embodiment which employ | adopted multiple chamfering is shown, (a) is a top view of an adsorption member, (b) is a top view of a board | substrate, (c) is sectional drawing which shows the assembly | attachment state of an adsorption member and a board | substrate. Explanatory drawing of an example of the adsorption | suction member reproduction | regenerating method in this Embodiment

DESCRIPTION OF SYMBOLS 1, 2 Drying apparatus 100, 200 Chamber 101, 201 Mounting base 102, 202 Adsorption member 102a Adsorption member center part 102b Adsorption member outer peripheral part 110 Lifting mechanism 111 Drive part 112 Control part 120,220 Exhaust pipe 121,221 Suction pump 122, 222 Pump control part 123, 223 Gas supply part P Substrate

Claims (4)

A drying apparatus configured to evaporate and absorb a solvent in a solution applied on a substrate,
A sealable chamber in which the substrate is housed, and a porous adsorbing member that is disposed opposite to the substrate in the chamber and adsorbs the solvent, and has an opening ratio at a central portion of the porous adsorbing member A drying apparatus characterized in that it is set to be larger than the opening ratio.   The drying apparatus according to claim 1, wherein the porous adsorbing member is an inorganic porous material.   The drying apparatus according to claim 1, wherein an exhaust port is provided at an upper portion of the chamber, and an exhaust unit that exhausts the atmosphere of the chamber from the exhaust port and depressurizes the chamber is installed.   The drying apparatus according to claim 3, wherein the exhaust port is disposed so as to face a central portion of the substrate.