JP2009039615A - Coater and coating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the uniformity of drying rate of a fluid material discharged from a plurality of discharge nozzles. <P>SOLUTION: This coater 1 operates in the following way: an organic EL liquid is discharged to the surface of a substrate 9 from a plurality of discharge nozzles 17 arranged at an equal interval, in the subscan direction perpendicular with the main scan direction, while an coating head 14 is run in the main scan direction. The substrate 9 is moved in the subscan direction each time the main scan is completed. In this case, the density of a solvent component of the organic EL liquid in the peripheral atmosphere of a linear element formed by the discharge nozzle 17 at the rear side of the relative moving direction of the substrate 9 in the subscan direction, becomes comparatively low right after one main scan. However, the remedy is that the cooling of the substrate 9 by water circulating through a flow path 111 inside a substrate retaining part 11, delays the drying rate of the organic EL liquid and a following main scan can be performed before the drying process. Thus, it is inhibited to allow the drying process of the organic EL liquid discharged from a plurality of discharge nozzles 17 to terminate right after the discharge under different conditions, and the improvement of the uniform drying rate of the organic EL liquid can be achieved. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technique for applying a flowable material containing a volatile solvent to a substrate.

  Conventionally, as an apparatus for applying a fluid material such as a resist solution on a semiconductor substrate, a nozzle that continuously ejects the fluid material is scanned on the substrate as disclosed in Patent Documents 1 and 2. Thus, there is known a coating apparatus that applies a fluid material on a substrate in a plurality of parallel lines, and applies the fluid material to the entire main surface of the substrate by spreading and contacting each other.

  In such a coating apparatus, various techniques for improving the uniformity of the film thickness of the flowable material have been proposed. For example, in Patent Document 1, a semiconductor substrate coated with a coating liquid by a resist coating apparatus is exposed to a solvent atmosphere of the coating liquid in a solvent atmosphere apparatus provided separately from the resist coating apparatus, thereby removing the solvent from the surface of the coating liquid. A technique for reducing the viscosity of the surface of the coating liquid by adhering to the surface of the coating liquid, and then forming an air flow in a container in which the substrate is accommodated and flattening the surface of the coating liquid by the air flow is disclosed. In the coating film forming apparatus of Patent Document 2, a drying prevention plate that covers almost the entire substrate is provided at a position within 2 mm above the substrate, and a coating liquid for an insulating film is formed in a linear gap formed on the drying prevention plate. By scanning a nozzle that discharges the substrate with respect to the substrate, the coating liquid is uniformly applied onto the substrate. Thereby, a high concentration solvent atmosphere is formed between the substrate and the drying prevention plate, and drying of the coating solution applied to the substrate is suppressed.

  By the way, an application apparatus that applies a fluid material to a substrate by scanning a nozzle that discharges the fluid material applies a fluid material containing a pixel forming material to a glass substrate for a flat display device. Applications are also being studied. In a typical example, the fluid material is applied in stripes at a predetermined pitch by repeatedly scanning a nozzle along a partition formed on a substrate. At this time, on the substrate, the solvent component evaporates from each line (linear element) of the flowable material and is dried in the order in which these lines are applied. In the fluid material, the pixel forming material is sufficiently dispersed until it dries and is fixed almost uniformly on the substrate. However, if the time from application to the end of drying is short, the degree of dispersion of the pixel forming material varies. Thus, the drying of the flowable material ends in a state different from the above region.

  Since the amount of the solvent component that evaporates from the surrounding fluid material is smaller in the line on the start end side and the line on the end side of the application on the substrate than in the central part of the application region, the concentration of the solvent component in the atmosphere is small. Lower. For this reason, the drying time of the fluid material is shorter than in other regions, and the dispersion state of the pixel forming material is different from the central portion. Therefore, in Patent Document 3, the flowable material is applied to the non-application area outside the application area (forms a dummy line) on each of the application start and end sides on the substrate. A method for suppressing the drying time of the ink from becoming shorter than other regions is disclosed.

In Patent Document 4, by providing a heater on a stage on which a substrate is placed in a coating apparatus, drying and evaporation of the solvent of the processing liquid applied to the substrate is promoted, and the processing liquid is cured to the extent that it does not flow. A technique is disclosed, and in Patent Document 5, the drying speed adjustment is made of a solvent having a high boiling point at the same position as the liquid droplets for red dot forming liquid having a low boiling point and a fast drying speed compared to other colors. Disclosed is a technique in which the drying speed of the red dot-forming liquid droplets is made equal to that of other color droplets by discharging the liquid droplets.
JP 2003-17402 A Japanese Patent Laid-Open No. 2005-13787 JP 2007-144240 A JP 2006-164905 A JP 2006-212589 A

  On the other hand, in order to improve the tact time in the coating apparatus, the flowable material is striped on the glass substrate by repeating scanning of a plurality of nozzles and step movement of the substrate in a direction perpendicular to the scanning direction. Since the fluid material is not applied to the rear side of the substrate in the step movement direction, the fluid material applied by the nozzle located at the rearmost side in the step movement direction among the plurality of nozzles. In the vicinity of the line, the concentration of the solvent component in the atmosphere is lower than that around the line of the flowable material applied by other nozzles. For this reason, the flowable material line applied by the rearmost nozzle dries faster than the flowable material lines applied by the other nozzles, and the dispersion state of the pixel forming material differs from the other lines. End up. As a result, when the substrate is viewed as a whole, coating unevenness occurs, and the display quality in the flat display device after becoming a product may deteriorate.

  The present invention has been made in view of the above problems, and an object of the present invention is to improve the uniformity of the drying rate of the flowable material discharged from a plurality of discharge ports.

  The invention described in claim 1 is a coating apparatus for applying a flowable material to a substrate, a substrate holding unit for holding the substrate, a cooling means for cooling the substrate, a volatile solvent, and the substrate. A discharge mechanism for discharging a flowable material including a material to be applied toward the substrate from a plurality of discharge ports arranged at equal intervals in a sub-scan direction parallel to the substrate; and the discharge mechanism in the sub-scan direction. The substrate is moved relative to the substrate in a main scanning direction perpendicular to the substrate and parallel to the substrate, and the substrate is moved relative to the discharging mechanism each time relative movement of the discharging mechanism in the main scanning direction is completed. A moving mechanism that moves relatively in the sub-scanning direction.

  A second aspect of the present invention is the coating apparatus according to the first aspect, wherein the cooling means cools the substrate holding part.

  Invention of Claim 3 is a coating device of Claim 1 or 2, Comprising: The said solvent contains the main solvent and the solvent whose volatility is lower than the said main solvent.

  A fourth aspect of the present invention is the coating apparatus according to any one of the first to third aspects, wherein the material applied on the substrate is a pixel forming material for an organic EL display device.

  The invention according to claim 5 is a coating method for applying a flowable material to a substrate, wherein a) a step of cooling the substrate, and b) a volatile solvent and the substrate in parallel with the step a). Discharge having the plurality of discharge ports while discharging a fluid material including a material to be applied onto the substrate from a plurality of discharge ports arranged at equal intervals in a sub-scanning direction parallel to the substrate. Moving the mechanism relative to the substrate in a main scanning direction perpendicular to the sub-scanning direction and parallel to the substrate; and c) moving the substrate relative to the ejection mechanism relative to the sub-scanning direction. And d) a step of repeating the step b) and the step c).

  According to the present invention, it is possible to improve the uniformity of the drying rate of the fluid material discharged from the plurality of discharge ports.

  In the invention of claim 2, the substrate can be easily cooled. In the invention of claim 3, the volatility of the fluid material is reduced, and the fluid material discharged from the plurality of ejection ports is dried. The uniformity of the speed can be further improved, and the invention according to claim 4 can suppress a deterioration in display quality due to coating unevenness in the organic EL display device.

  FIG. 1 is a plan view showing a coating apparatus 1 according to an embodiment of the present invention, and FIG. 2 is a front view of the coating apparatus 1 (from the (−Y) side in FIG. 1 toward the (+ Y) direction). Figure). The coating apparatus 1 is an apparatus that applies a flowable material including a pixel forming material for a flat display device to a glass substrate 9 for flat display devices (hereinafter simply referred to as “substrate 9”). In the present embodiment, in the coating apparatus 1, a substrate 9 for an organic EL (Electro Luminescence) display device of an active matrix driving system is applied onto the substrate 9 as a volatile solvent and a light emitting material of one color. A fluid material containing an organic EL material (hereinafter referred to as “organic EL liquid”) is applied.

  As shown in FIG. 2, the coating apparatus 1 includes a substrate holding portion 11 that holds the substrate 9 in contact with one main surface (the main surface on the (−Z) side in FIG. 2) of the substrate 9. As shown in FIGS. 1 and 2, the substrate holding portion 11 is horizontally moved in a predetermined direction parallel to the main surface of the substrate 9 (that is, the Y direction in FIG. 1 and hereinafter referred to as “sub-scanning direction”). And a substrate moving mechanism 12 that rotates about an axis oriented in the vertical direction (that is, the Z direction).

  As shown by a broken line in FIG. 1, a water flow path 111 is formed inside the substrate holding part 11. The flow path 111 is repeatedly bent in order in the X direction and the Y direction so as to pass through substantially the entire substrate holding portion 11 along the XY plane in FIG. Both ends of the flow path 111 are connected to the circulation unit 112, and the water temperature is adjusted to a predetermined temperature (for example, 15 ° C.) lower than the temperature around the coating apparatus 1 (normal temperature) in the circulation unit 112. Circulates through the circulation part 112 and the flow path 111, whereby the substrate holding part 11 is maintained at a substantially constant temperature.

  In the coating region 91 (indicated by a thin line rectangle in FIG. 1) on the (+ Z) side main surface 90 of the substrate 9, a plurality of partition walls each extending in the X direction in FIG. 1 are constant in the Y direction. Are arranged at a pitch (for example, a pitch of 100 to 150 micrometers (μm)).

  The coating apparatus 1 also has an alignment mark detector 13 for imaging and detecting an alignment mark (not shown) formed on the substrate 9, and a main surface of the substrate 9 held by the substrate holder 11 (see FIG. 2). A coating head 14 that is a discharge mechanism that discharges a fluid material toward 90, and a direction in which the coating head 14 is parallel to the main surface 90 of the substrate 9 and perpendicular to the sub-scanning direction (that is, the X direction in FIG. Hereinafter, the head moving mechanism 15 that moves horizontally in the “main scanning direction”) and the organic EL liquid from the coating head 14 are provided on both sides of the substrate holder 11 with respect to the moving direction of the coating head 14 (that is, the X direction). 1 and 2 and a flowable material supply unit 18 for supplying a flowable material to the coating head 14 and, as shown in FIG. 1, a control unit 2 for controlling these configurations. . In the coating apparatus 1, the head moving mechanism 15 and the substrate moving mechanism 12 move the coating head 14 relative to the substrate 9 in the main scanning direction (that is, perform main scanning) and move the substrate 9 relative to the coating head 14. Thus, the moving mechanism moves relatively in the sub-scanning direction (that is, performs sub-scanning).

  As shown in FIGS. 1 and 2, the coating head 14 includes a plurality (in this embodiment, five) of discharge nozzles 17. On the (−Z) side end face of each discharge nozzle 17, discharge ports (in FIG. 2, only the discharge ports of the two discharge nozzles 17 are denoted by reference numeral 171) are formed. The same type of organic EL liquid is continuously discharged. The five discharge nozzles 17 are arranged substantially linearly in the X direction (that is, the main scanning direction) and are slightly shifted in the Y direction (that is, the sub scanning direction). In the coating apparatus 1, the positions of the plurality of discharge nozzles 17 in the Y direction can be individually adjusted, and the discharge ports 171 of the five discharge nozzles 17 are arranged at equal intervals in the sub-scanning direction and are adjacent to each other. The distance between the centers of the discharge ports 171 of the two discharge nozzles 17 in the sub-scanning direction is made equal to three times the pitch of the partition walls on the substrate 9 in the Y direction.

  When the organic EL liquid is applied to the application region 91 shown in FIG. 1, the region between the partition walls on the main surface 90 from each discharge nozzle 17 (that is, the region extending in the main scanning direction and perpendicular to the main scanning direction). 4 is a region denoted by reference numeral 93 between two partition walls 92 adjacent to each other in FIG. 4 to be described later, and is hereinafter referred to as a “linear region”). Is done. As will be described later, in the coating apparatus 1, in a plurality of linear regions arranged at a constant pitch in the sub-scanning direction (a pitch equal to the partition pitch, hereinafter referred to as “region pitch”), the sub-scanning direction is applied. The organic EL liquid is applied to the linear region that exists every two. That is, two linear regions to which other types of organic EL liquids are applied are sandwiched between two linear regions to which the organic EL liquid is applied by the coating apparatus 1. Yes.

  Next, application of the organic EL liquid by the application apparatus 1 will be described. FIG. 3 is a diagram showing a flow of application of the organic EL liquid. In the coating apparatus 1 of FIG. 1, the circulation unit 112 is always driven (of course, the drive of the circulation unit 112 may be started immediately before application of the organic EL liquid), and water at a predetermined temperature is circulated. By circulating through 112 and the flow path 111, the substrate holding part 11 is cooled to a substantially constant temperature. Then, the substrate 9 is placed and held on the substrate holding unit 11 by the external transport mechanism, whereby the substrate 9 is cooled via the substrate holding unit 11 (step S11). The substrate 9 is continuously maintained (cooled) at a constant temperature while being held on the substrate holder 11 (that is, during the operation of applying the organic EL liquid to the substrate 9).

  When the substrate 9 is held by the substrate holding unit 11, the substrate moving mechanism 12 is driven based on the output from the alignment mark detection unit 13 to move and rotate the substrate 9, and the coating shown by the solid line in FIG. 1. It is located at the start position (step S12). As described above, a plurality of partition walls parallel to each other are arranged on the main surface 90 of the substrate 9, and a linear region is defined as a region between the partition walls on the main surface 90. By arranging at the position, in the coating apparatus 1, a plurality of linear regions each extending in the main scanning direction are arranged and set on the main surface 90 at a constant region pitch in the sub-scanning direction perpendicular to the main scanning direction. In this state, the substrate 9 to be processed is prepared. At this time, the coating head 14 is in the vicinity of the end on the (+ Y) side of the substrate 9 in the sub-scanning direction, and in the main scanning direction, a standby position indicated by a solid line in FIG. 1 and FIG. (Above the liquid receiving part 16 on the (−X) side).

  Subsequently, the coating head 14 is controlled by the control unit 2 to start the discharge of the organic EL liquid from the five discharge nozzles 17 (step S13), and the head moving mechanism 15 is further controlled to control the main of the coating head 14. Movement in the scanning direction (that is, main scanning from the (−X) side to the (+ X) side in FIG. 1) is started. As a result, the coating head 14 continues in the main scanning direction while discharging the organic EL liquid continuously (without interruption) from each of the plurality of discharge ports 171 toward the main surface 90 of the substrate 9 at a constant flow rate. The organic EL liquid is applied in stripes to the five linear regions of the application region 91 of the substrate 9 (step S14).

  Then, the application head 14 moves to a standby position indicated by a two-dot chain line in FIGS. 1 and 2 (that is, above the (+ X) side liquid receiving unit 16), whereby a stripe pattern by the organic EL liquid is used. Is formed. In the following description, a line corresponding to one ejection port 171 in the pattern is referred to as a linear element. Note that the (+ X) side and (−X) side non-application regions (and the (+ Y) side and (−Y) side non-application regions) of the application region 91 in FIG. 1 are not shown. Since it is covered with a mask, the organic EL liquid is not applied directly onto the substrate 9.

  FIG. 4 is a view showing a cross section of the substrate 9 perpendicular to the main scanning direction. In the coating apparatus 1, as described above, a plurality of linear regions (that is, regions on the main surface 90 between two partition walls 92 adjacent to each other as shown in FIG. 4, The organic EL liquid is applied to the linear regions 93 that are present every two in the sub-scanning direction.

  At this time, as described above, the substrate 9 is cooled by the water circulating through the circulation unit 112 and the flow path 111. In the present embodiment, the organic EL liquid contains a main solvent having a boiling point of about 150 ° C. or lower (for example, toluene, xylene, anisole, etc., which volatilizes at room temperature) and is more volatile than the main solvent. Low solvents (for example, high boiling point swazole (trade name of Maruzen Petroleum Corporation), 1,2,3,4-tetramethylbenzene, cyclohexylbenzene, isopropylbiphenyl, etc.) are also contained in a smaller amount than the main solvent (the following In the description, the term “solvent” simply means a solvent containing all the solvents contained in the organic EL liquid.) The boiling point of the organic EL liquid (more precisely, the boiling point of the solvent in the organic EL liquid) It becomes higher than the boiling point of the main solvent, and the volatility of the organic EL liquid (the volatility of the solvent in the organic EL liquid) is reduced.

  As a result, the organic EL liquid applied on the plurality of linear regions 93 by the plurality of ejection nozzles 17 requires a relatively long time until drying (that is, evaporation of the solvent from the organic EL liquid) is almost completed. Actually, after the application onto the substrate 9, the drying of the organic EL liquid is not completed until the coating head 14 repeats sub-scanning and main scanning to be described later a plurality of times (that is, ejection onto the substrate 9 is performed). The dried organic EL liquid does not finish drying while the next main scanning of the coating head 14 is performed. Finally, as shown in FIG. 4, the organic EL material is left on the substrate 9 in a semi-dried state slightly containing a solvent (that is, applied), and each linear element 94 becomes an organic EL material. Film (thickness is emphasized).

  When the coating head 14 moves to the standby position, the substrate moving mechanism 12 is driven, and the substrate 9 moves together with the substrate holder 11 in the (+ Y) direction (ie, the sub-scanning direction) by a distance equal to 15 times the area pitch ( Step S15). At this time, in the coating head 14, the organic EL liquid is continuously discharged from the five discharge nozzles 17 toward the liquid receiving unit 16.

  When the movement of the substrate 9 in the sub-scanning direction is completed, it is confirmed by the control unit 2 whether or not the substrate 9 and the substrate holding unit 11 have moved to the application end position indicated by the two-dot chain line in FIG. 1 (step S16). ). If it has not moved to the application end position, the process returns to step S14, and the application head 14 discharges the organic EL liquid from the five discharge nozzles 17 from the (+ X) side of the substrate 9 in the (−X) direction. By moving in the (ie, main scanning direction), the organic EL liquid is applied to the linear region 93 on the substrate 9 (step S14). Thereafter, it is confirmed whether or not the substrate 9 has moved in the sub-scanning direction and has moved to the coating end position (steps S15 and S16).

  In the coating apparatus 1, the substrate 9 is relatively moved in the sub-scanning direction every time the coating head 14 is moved in the main scanning direction until the substrate holding unit 11 and the substrate 9 are positioned at the coating end position ( That is, the movement of the coating head 14 in the main scanning direction and the step movement of the substrate 9 toward the (+ Y) side are repeated), whereby the organic EL liquid is three times the area pitch in the coating region 91 of the substrate 9. Are applied in stripes arranged at a pitch equal to (steps S14 to S16). In the coating apparatus 1, the direction in which the application of the organic EL liquid proceeds on the substrate 9 in the sub-scanning direction (that is, the relative movement direction of the coating head 14 with respect to the substrate 9) is the movement direction of the substrate 9 by the substrate moving mechanism 12. Is in the opposite direction.

  When the substrate 9 moves to the application end position, the discharge of the organic EL liquid from the five discharge nozzles 17 is stopped (Steps S16 and S17), and the application of the organic EL liquid to the substrate 9 by the coating apparatus 1 is completed. . The substrate 9 that has been applied by the coating apparatus 1 is transported to another coating apparatus or the like, and two organic EL liquids other than the organic EL liquid applied by the coating apparatus 1 are applied. In the coating apparatus 1, the organic EL liquid is actually continuously applied to the plurality of substrates 9.

  By the way, in the above-described organic EL liquid application operation, in the atmosphere around the linear element of the organic EL liquid applied by the three discharge nozzles 17 in the vicinity of the center among the plurality (five) of discharge nozzles 17. The concentration of the solvent component of the organic EL liquid becomes high, and even around the linear element of the organic EL liquid applied by the discharge nozzle 17 on the (+ Y) side, the most (− The concentration of the solvent component of the organic EL liquid in the atmosphere increases due to the influence of the linear elements of the organic EL liquid applied by the discharge nozzle 17 on the Y) side.

  However, the discharge nozzle 17 on the (−Y) side (that is, the nozzle on the rear side in the relative movement direction of the substrate in the sub-scanning direction, hereinafter referred to as “rear nozzle”. However, when attention is paid to the coating head 14, On the (−Y) side of the linear element of the organic EL liquid applied by the above (hereinafter, the linear element formed by the rear nozzle is referred to as “rear side linear element”). The other organic EL liquid linear elements are not formed, and the organic EL liquid linear elements applied in parallel by the discharge nozzles 17 in the vicinity of the center are arranged only on the (+ Y) side. . For this reason, in the periphery of the rear linear element applied by the (−Y) side rear nozzle, the linear elements applied by the (+ Y) side discharge nozzle 17 and the three discharge nozzles 17 in the vicinity of the center. The concentration of the solvent component of the organic EL liquid is lower than the surroundings. To be exact, the concentration of the solvent component of the organic EL liquid in the atmosphere on the (−Y) side of the rear linear element is lower than the concentration on the (+ Y) side of the rear linear element around the rear linear element. Become.

  Therefore, temporarily, the circulation unit 112 and the flow path 111 are omitted in the coating apparatus 1 (that is, the substrate 9 is not cooled), and the coating operation of the comparative example is performed using an organic EL liquid containing only the main solvent as a solvent. In this case, the (−Y) side portion of the rear linear element dries much faster than the (+ Y) side portion, and the illustration of the partition wall 92 is omitted. As shown in A, in the (−Y) side rear linear element 94a formed of a semi-dry organic EL material, the (−Y) side portion (a portion including a square protrusion. (+ Y)). The difference D1 (hereinafter referred to as “edge film thickness difference”) between the film thickness of the part on the side and the film thickness on the (+ Y) side is substantially zero. The dispersion state of the organic EL material having a cross-sectional shape perpendicular to the main scanning direction in the plurality of linear elements 94 is not constant.

  Then, when the rear linear elements 94a of the organic EL material having a deviation in thickness are formed periodically (that is, every five pieces) in the application region, uneven application (also referred to as stitching). In some cases, the display quality of the organic EL display device after the product becomes a product deteriorates. In the rear linear element, the film thickness of the part on the side of the other linear element formed simultaneously is not necessarily smaller than the film thickness of the part on the opposite side of the part. Depending on the type, the film thickness of the part on the side of the other linear element formed at the same time may be larger than the film thickness of the part on the opposite side to the part.

  If only one nozzle is provided in the coating head, FIG. When coating is performed at the same pitch as in the case of A, a plurality of linear elements on the substrate 9 are formed under substantially constant conditions, and FIG. As shown in B, the cross-sectional shape perpendicular to the main scanning direction in the plurality of linear elements 94 is substantially constant. In this case, the coating unevenness is not recognized, but the time (tact time) required for forming the linear element 94 on the entire substrate 9 becomes long.

  In contrast to the comparative example, in the coating apparatus 1 of FIG. 1, the substrate 9 is indirectly cooled by the circulation unit 112 and the flow path 111 via the substrate holding unit 11 when the organic EL liquid is applied to the substrate 9. The drying rate of the organic EL liquid on the substrate 9 is slowed down as a whole. Thereby, when the organic EL liquid is discharged from the plurality of discharge ports 171, the discharge nozzle 17 on the (+ Y) side and the three discharges near the center are arranged around the rear linear element applied by the rear nozzle. The drying of the organic EL liquid is completed in a state where the concentration of the solvent component of the organic EL liquid is lower than that around the linear element applied by the nozzle 17 (that is, the solvent evaporates until it becomes a semi-dry state). In the time required for drying the rear linear element, a state in which a new linear element is formed on the (−Y) side of the rear linear element (that is, the ambient atmosphere is the rear linear element). At the same time, the ratio of the time in the same state as in the other linear elements formed is increased. As described above, in the coating apparatus 1, the organic EL liquid discharged from the plurality of discharge ports 171 is prevented from being dried under different conditions immediately after discharge, and the uniformity of the drying speed of the organic EL liquid is improved. The As a result, the non-uniformity of the cross-sectional shape of the linear element 94 of the organic EL material formed on the substrate 9 (variation in edge film thickness difference) is reduced, and the organic EL display manufactured using the substrate 9 is achieved. It is possible to suppress deterioration in display quality due to uneven application in the apparatus.

  Further, in the coating apparatus 1, the organic EL liquid includes a main solvent and a solvent having lower volatility than the main solvent, thereby increasing the boiling point of the organic EL liquid to an extent that it is difficult to volatilize at room temperature. The volatility of the liquid can be reduced. Thereby, the uniformity of the drying rate of the organic EL liquid discharged from the plurality of discharge ports 171 can be further improved.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications are possible.

  In the coating apparatus 1 of FIG. 1, the substrate 9 is easily cooled by cooling the substrate holding unit 11 with water circulating through the circulation unit 112 and the flow path 111 (of course, a coolant other than water may be used). For example, a Peltier element that cools the substrate holding unit 11 may be provided on the opposite side of the substrate holding unit 11 from the substrate 9, and the substrate 9 may be indirectly cooled. Further, in the coating apparatus 1a shown in FIG. 6 in which the flow path 111 and the circulation unit 112 inside the substrate holding unit 11 are omitted, the substrate holding unit 11, the substrate moving mechanism 12, the alignment mark detection unit 13, the coating head 14, and the head A chamber 31 in which the moving mechanism 15 and the liquid receiving unit 16 are disposed may be provided. When the organic EL liquid is applied on the substrate 9 by the coating apparatus 1a of FIG. The substrate 9 on the holding unit 11 is cooled. As a result, drying of the organic EL liquid discharged from the plurality of discharge ports 171 onto the substrate 9 is prevented from being finished under different conditions immediately after discharge, and the uniformity of the drying rate of the organic EL liquid is improved. be able to. As described above, the method for cooling the substrate 9 can be realized by various configurations. When the chamber 31 is used for cooling the substrate 9, the substrate holding unit is not in contact with the main surface on the (−Z) side of the substrate 9 and holds the substrate 9, but in the Y direction of the substrate 9. For example, the substrate 9 may be held by holding the end of the substrate.

  Further, depending on the display quality required in the organic EL display device, a plurality of discharges can be obtained only by including the main solvent and a solvent having lower volatility than the main solvent without cooling the substrate 9. The uniformity of the drying rate of the organic EL liquid discharged from the outlet 171 may be improved.

  In the above embodiment, a plurality of linear elements 94 formed of an organic EL liquid containing a luminescent material of the same color are arranged on the main surface 90 at a pitch of three times the area pitch, and on the substrate 9. Although it is possible to appropriately form a pattern of the light emitting material, a fluid material that includes a hole transport material in addition to a volatile solvent (for example, water) may be applied to the substrate 9. Also in this case, in the coating apparatus, it is possible to improve the uniformity of the drying speed of the flowable material discharged from the plurality of discharge ports 171 and to suppress the variation in the cross-sectional shape of the linear element after drying, In the organic EL display device, it is possible to suppress deterioration in display quality depending on variations in the cross-sectional shape of the hole transport layer. The “hole transport material” is a material for forming a hole transport layer of the organic EL display device, and the “hole transport layer” is a hole to the organic EL layer formed of the organic EL material. This includes not only a hole transport layer in a narrow sense that transports, but also includes a hole injection layer that injects holes.

  In the coating apparatus, for example, three discharge nozzles 17 are provided in the coating head 14, and three types of organic EL having different colors from red (R), green (G), and blue (B) from these discharge nozzles 17 are provided. Three types of organic EL liquids each containing a material may be simultaneously ejected and applied to the substrate 9. Further, in the coating head 14, as long as there are two or more discharge nozzles 17 that discharge the fluid material, other numbers may be used.

  In the coating apparatus, instead of moving the substrate 9 and the substrate holding unit 11 by the substrate moving mechanism 12, the coating head 14 moves in the sub-scanning direction, so that the substrate 9 moves relative to the coating head 14 in the sub-scanning direction. It may be broken. Further, instead of the movement of the coating head 14 by the head moving mechanism 15, the substrate 9 and the substrate holder 11 move in the main scanning direction, so that the coating head 14 moves relative to the substrate 9 in the main scanning direction. Also good.

  In the substrate 9 to be processed in the above embodiment, the linear region 93 is defined by the partition wall 92, but the coating apparatus can also apply a fluid material onto the substrate 9 on which the partition wall is not formed. In this case, it is considered that a plurality of linear regions extending in the main scanning direction are virtually arranged on the main surface 90 at a constant region pitch in the sub-scanning direction according to the pixel interval of the display device which is the final product. In addition, the flowable material is applied by the application device.

  The coating device can also be used when a plurality of organic EL display devices are manufactured from a single substrate (so-called multi-surface processing). Further, by applying a fluid material containing a pixel forming material (organic EL material or hole transport material) for an organic EL display device as a material to be applied on the substrate 9 onto the substrate 9 using an application device, Although the deterioration of display quality due to coating unevenness in the EL display device is suppressed, the nozzle printing type coating device is a coloring material for a substrate for other flat display devices such as a liquid crystal display device and a plasma display device, for example. Or a flowable material including other types of pixel forming materials such as fluorescent materials. Also in this case, in the flat display device, it is possible to suppress deterioration in display quality due to coating unevenness.

  Moreover, the coating device may be used for coating various types of fluid materials on various substrates such as a semiconductor substrate in addition to the substrate for a flat display device.

It is a top view which shows a coating device. It is a front view of a coating device. It is a figure which shows the flow of application | coating of organic electroluminescent liquid. It is a figure which shows the cross section of the linear element on a board | substrate. It is a figure which shows the cross section of the linear element formed in a comparative example. It is a figure which shows the cross section of the linear element formed in another comparative example. It is a figure which shows the other example of a coating device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1a Coating device 9 Substrate 11 Substrate holding part 12 Substrate moving mechanism 14 Coating head 15 Head moving mechanism 31 Chamber 32 Temperature control part 111 Flow path 112 Circulation part 171 Discharge port S11, S13 to S17 Steps

Claims (5)

An application device for applying a flowable material to a substrate,
A substrate holder for holding the substrate;
Cooling means for cooling the substrate;
A discharge mechanism for discharging a flowable material including a volatile solvent and a material applied on the substrate toward the substrate from a plurality of discharge ports arranged at equal intervals in a sub-scanning direction parallel to the substrate; ,
The ejection mechanism is moved relative to the substrate in a main scanning direction perpendicular to the sub-scanning direction and parallel to the substrate, and the relative movement of the ejection mechanism in the main scanning direction is completed each time. A moving mechanism for moving the substrate relative to the ejection mechanism in the sub-scanning direction;
A coating apparatus comprising: The coating apparatus according to claim 1,
The coating apparatus, wherein the cooling means cools the substrate holding part. The coating apparatus according to claim 1 or 2,
The coating apparatus, wherein the solvent includes a main solvent and a solvent having lower volatility than the main solvent. The coating apparatus according to any one of claims 1 to 3,
A coating apparatus, wherein the material applied onto the substrate is a pixel forming material for an organic EL display device. An application method for applying a flowable material to a substrate,
a) cooling the substrate;
b) In parallel with the step a), a plurality of discharge ports in which a volatile solvent and a flowable material containing a material applied on the substrate are arranged at equal intervals in the sub-scanning direction parallel to the substrate Moving the discharge mechanism having the plurality of discharge ports relative to the substrate in a main scanning direction perpendicular to the sub-scanning direction and parallel to the substrate, while discharging toward the substrate from
c) moving the substrate relative to the ejection mechanism in the sub-scanning direction;
d) repeating the step b) and the step c);
A coating method comprising:

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