JP7312204B2 - NOZZLE CLEANING DEVICE, NOZZLE CLEANING METHOD, AND COATING DEVICE - Google Patents

Description

The present invention is for precision electronic devices such as glass substrates for liquid crystal displays, semiconductor substrates, glass substrates for PDPs, glass substrates for photomasks, substrates for color filters, substrates for recording disks, substrates for solar cells, and substrates for electronic paper. A coating device for coating a substrate, a rectangular glass substrate, a flexible film liquid crystal substrate, an organic EL substrate (hereinafter simply referred to as "substrate") by discharging a coating liquid from a discharge port provided at the lower end of a nozzle. and a nozzle cleaning technique for cleaning the lower end of the nozzle by removing deposits adhering to the lower end of the nozzle with a nozzle abutting member.

2. Description of the Related Art Conventionally, a nozzle that ejects a processing liquid from a slit-shaped ejection port has been used to apply a processing liquid to a substrate, as described in Japanese Unexamined Patent Application Publication No. 2002-200013. In this nozzle, there is a case where a substance such as a dried and hardened processing liquid adheres to the lower end portion where the ejection port is provided, and drops to stain the substrate. Therefore, a nozzle cleaning process is performed before starting application by the nozzles. This nozzle cleaning process is performed by a nozzle cleaning device having a nozzle contact member capable of coming into contact with the lower end of the nozzle, and a moving part for moving the nozzle contact member relative to the nozzle in the extending direction of the ejection port. be done.

JP 2018-187597 A

In the nozzle cleaning device described in Patent Document 1, the nozzle contact member is moved relative to the nozzle at a constant speed in the extending direction while the concave portion of the nozzle contact member is kept in contact with the lower end portion of the nozzle. As a result, the processing liquid adhering to the side surface of the lower end of the nozzle is removed. However, you may encounter the following issues: In the nozzle disclosed in Patent Document 1, the portion that first contacts the nozzle contact member in the nozzle cleaning process is the inclined surface, whereas the portion that contacts the nozzle contact member last is the stepped portion. Therefore, the processing liquid scraped from the nozzle by the nozzle contact member may remain on the stepped portion. Moreover, when the remaining amount of the processing liquid increases, the remaining processing liquid may adhere to the substrate when the nozzle is used to apply the processing liquid to the next substrate. This is one of the main factors that deteriorate the film thickness uniformity of the treatment liquid applied to the substrate. In addition, the residual processing liquid may adhere to areas other than the area to be coated.

Such a problem is not limited to the nozzle cleaning process of cleaning a nozzle provided with a step portion on the terminal end side in the relative movement direction of the nozzle contact member. For example, as shown in FIGS. 2 and 3 to be described later, a nozzle provided with a notch portion at the center of the lower end of the nozzle in the direction of relative movement (extending direction of the discharge port), or a nozzle shown in FIG. 7 to be described later. As shown, even in the case of a nozzle having an inclined portion on the terminal end side, the above problem may occur when the nozzle contact member is moved at a constant speed to perform the nozzle cleaning process.

The present invention has been made in view of the above problems, and the nozzle abutting member is moved relative to the nozzle in the extending direction of the ejection opening of the nozzle while the nozzle abutting member is kept in contact with the lower end of the nozzle, and adheres to the nozzle. It is an object of the present invention to provide a nozzle cleaning device, a nozzle cleaning method, and a coating device capable of suppressing the amount of processing liquid remaining in the nozzle when the processing liquid is removed.

A first aspect of the present invention is a nozzle cleaning device for cleaning a nozzle that ejects a processing liquid from a slit-shaped ejection port provided at a lower end portion that protrudes downward from a main body portion of the nozzle, the lower end portion of the nozzle a nozzle abutting member capable of abutting against the nozzle, a moving part that moves the nozzle abutting member relatively to the nozzle in the extending direction of the discharge port while the nozzle abutting member is in contact with the lower end of the nozzle, and the nozzle by the moving part a speed control unit for controlling the moving speed of the contact member, the lower end portion having a projecting portion projecting downward from the main body portion with a constant projecting amount, and a projecting portion whose projecting amount is continuous as it progresses in the extending direction. Alternatively, when a retraction portion that is discontinuously retracted toward the main body portion by decreasing the amount of protrusion of the protrusion portion is provided, the nozzle contact member that is moved relative to the nozzle by the moving portion is , when moving the projecting portion, when moving from the projecting portion to the retracted portion, and when moving between the retracted portions, the nozzle continues to contact the lower end portion, and the speed control section moves the nozzle contact member to the second position at the projecting portion. While the nozzle contact member is moved at a moving speed of 1, the moving speed of the nozzle contact member is reduced from the first moving speed when the nozzle contact member moves from the projecting portion to the retreating portion.

A second aspect of the present invention is a nozzle cleaning method for cleaning a nozzle that ejects a processing liquid from a slit-shaped ejection port provided at a lower end projecting downward from a main body of the nozzle. A first step of bringing the nozzle contact member into contact with the lower end portion, and a second step of moving the nozzle contact member relative to the nozzle in the extending direction of the discharge port while keeping the nozzle contact member in contact with the lower end portion. and the second step includes a constant-velocity moving step of moving the nozzle contact member at a first moving speed at the protruding portion of the lower end portion, the protruding amount of which downwardly protrudes from the main body portion is constant; As the nozzle contact member moves from the projecting portion to the retracted portion, the amount of protrusion decreases continuously or discontinuously as the nozzle contact member advances in the installation direction. a decelerating movement step of decelerating the moving speed of the contact member from a first moving speed, wherein the constant-velocity moving step and the decelerating-moving step are performed by moving the nozzle contact member relatively to the nozzle. is carried out in a state in which the lower end of the nozzle is kept in contact when moving the protruding portion, when moving from the protruding portion to the retracted portion, and when moving the retracted portion. is characterized by

Further, in a third aspect of the present invention, there are provided: a nozzle for supplying a processing liquid to a substrate by discharging it from a slit-shaped discharge port provided at a lower end projecting downward from a main body of the nozzle; and the above nozzle cleaning device. , is provided.

While the nozzle contact member is in contact with the lower end of the nozzle, the nozzle contact member is moved in the extending direction of the ejection port. When relatively moved, the processing liquid remains in a part of the lower end of the nozzle. The residual position is in the vicinity of the boundary position adjacent to the protruding portion of the receding portion, that is, in the vicinity of the position where the amount of protrusion is continuously or discontinuously smaller than the amount of protrusion of the protruding portion. In particular, if the nozzle contact member is relatively moved at a constant first movement speed as in the conventional apparatus, the remaining amount of processing liquid at the boundary position increases. On the other hand, when the nozzle contact member passes the boundary position, that is, when the nozzle contact member relatively moves from the protruded portion to the retracted portion, if the relative movement speed is reduced from the first movement speed, the process The residual amount of liquid is greatly reduced.

The process that remains on the nozzle when the processing liquid adhering to the nozzle is removed by moving the nozzle contact member relative to the nozzle in the extending direction of the nozzle while keeping the nozzle contact member in contact with the lower end of the nozzle. The amount of liquid can be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram schematically showing the overall configuration of a coating device equipped with a nozzle cleaner, which is a first embodiment of a nozzle cleaning device according to the present invention; It is the perspective view seen from diagonally below the nozzle. It is a perspective view which shows the structure of a nozzle cleaner. 4 is a flowchart showing an example of nozzle cleaning processing by a nozzle cleaner that is the first embodiment of the nozzle cleaning device according to the present invention; FIG. 5 is a diagram schematically showing part of the operations performed according to the flowchart of FIG. 4; It is a figure which shows typically a part of operation|movement performed by 2nd Embodiment of the nozzle cleaning apparatus which concerns on this invention. It is a figure which shows typically a part of operation|movement performed by 3rd Embodiment of the nozzle cleaning apparatus which concerns on this invention.

FIG. 1 is a diagram schematically showing the overall construction of a coating apparatus equipped with a nozzle cleaner, which is a first embodiment of a nozzle cleaning apparatus according to the present invention. This coating apparatus 1 is a slit coater that coats the upper surface Wf of a substrate W that is horizontally transported from the left hand side to the right hand side in FIG. 1 with a processing liquid. In the following figures, in order to clarify the positional relationship of each part of the apparatus, the direction in which the substrate W is transported is referred to as the "X direction", and the horizontal direction from the left-hand side to the right-hand side of FIG. 1 is referred to as the "+X direction." , the opposite direction is called the “−X direction”. In addition, in the horizontal direction Y perpendicular to the X direction, the front side of the apparatus is referred to as "-Y direction" and the back side of the apparatus is referred to as "+Y direction". Furthermore, the upward direction and the downward direction in the vertical direction Z are referred to as "+Z direction" and "−Z direction", respectively.

First, an overview of the configuration and operation of the coating apparatus 1 will be described with reference to FIG. 1, and then the more detailed structure of the nozzle cleaner will be described. The basic configuration and operating principle of the coating device 1 are common to those described in Patent Document 1 previously disclosed by the applicant of the present application. Therefore, in this specification, among the respective configurations of the coating device 1, those to which the same configurations as those described in these known documents can be applied, and those whose structures can be easily understood from the descriptions in these documents. A detailed description of is omitted, and a characteristic part of the present embodiment will be mainly described.

In the coating apparatus 1, the input conveyor 100, the input transfer section 2, the floating stage section 3, the output transfer section 4, and the output conveyor 110 are arranged close to each other in this order along the transport direction Dt (+X direction) of the substrate W. As will be described in detail below, these form a transport path for the substrate W extending substantially horizontally. In the following description, when indicating the positional relationship in relation to the transport direction Dt of the substrate W, "upstream in the transport direction Dt of the substrate W" is simply referred to as "upstream" and "downstream in the transport direction Dt of the substrate W". side" may be abbreviated simply as "downstream side". In this example, the (-X) side corresponds to the "upstream side" and the (+X) side corresponds to the "downstream side" relative to a certain reference position.

A substrate W to be processed is carried into the input conveyor 100 from the left hand side of FIG. The input conveyor 100 includes a roller conveyor 101 and a rotation drive mechanism 102 that rotates the roller conveyor 101. By the rotation of the roller conveyor 101, the substrate W is horizontally conveyed downstream, that is, in the (+X) direction. The input transfer section 2 includes a roller conveyor 21 and a rotation/elevation drive mechanism 22 having a function of rotating and elevating the roller conveyor 21 . As the roller conveyor 21 rotates, the substrate W is further transported in the (+X) direction. Further, the vertical position of the substrate W is changed as the roller conveyor 21 moves up and down. The substrate W is transferred from the input conveyor 100 to the levitation stage section 3 by the input transfer section 2 configured as described above.

The levitation stage unit 3 includes a flat stage divided into three along the substrate transport direction Dt. That is, the levitation stage section 3 has an entrance levitation stage 31, a coating stage 32 and an exit levitation stage 33, and the upper surfaces of these stages form part of the same plane. On the upper surface of each of the entrance levitation stage 31 and the exit levitation stage 33, a large number of ejection holes for ejecting compressed air supplied from the levitation control mechanism 35 are provided in a matrix. The substrate W floats. In this way, the substrate W is supported in a horizontal position with the lower surface Wb of the substrate W separated from the upper surface of the stage. The distance between the lower surface Wb of the substrate W and the upper surface of the stage, that is, the floating amount, can be, for example, 10 micrometers to 500 micrometers.

On the other hand, on the upper surface of the coating stage 32, ejection holes for ejecting compressed air and suction holes for sucking air between the lower surface Wb of the substrate W and the upper surface of the stage are alternately arranged. The distance between the lower surface Wb of the substrate W and the upper surface of the coating stage 32 is precisely controlled by the levitation control mechanism 35 controlling the amount of compressed air ejected from the ejection holes and the amount of suction from the suction holes. As a result, the vertical position of the upper surface Wf of the substrate W passing above the coating stage 32 is controlled to a specified value. As a specific configuration of the levitation stage section 3, for example, one described in Japanese Patent No. 5346643 can be applied. The amount of floating on the coating stage 32 is calculated by the control unit 9 based on the results of detection by sensors 61 and 62, which will be described in detail later, and can be adjusted with high precision by airflow control.

The entrance floating stage 31 is provided with lift pins (not shown), and the floating stage section 3 is provided with a lift pin drive mechanism 34 for raising and lowering the lift pins.

The substrate W carried into the levitation stage section 3 via the input transfer section 2 is imparted with a propulsive force in the (+X) direction by the rotation of the roller conveyor 21 and conveyed onto the entrance levitation stage 31 . The entrance floating stage 31, coating stage 32, and exit floating stage 33 support the substrate W in a floating state, but do not have the function of moving the substrate W in the horizontal direction. The substrate W is transported in the levitation stage section 3 by the substrate transport section 5 arranged below the entrance levitation stage 31 , coating stage 32 and exit levitation stage 33 .

The substrate transfer unit 5 includes a chuck mechanism 51 that supports the substrate W from below by partially abutting on the peripheral edge of the lower surface of the substrate W, and a suction pad (not shown) provided on a suction member at the upper end of the chuck mechanism 51 . A suction/travel control mechanism 52 having a function of applying a negative pressure to hold the substrate W by suction and a function of reciprocating the chuck mechanism 51 in the X direction is provided. When the chuck mechanism 51 holds the substrate W, the lower surface Wb of the substrate W is positioned higher than the upper surface of each stage of the levitation stage section 3 . Therefore, the substrate W is held in a horizontal position as a whole by the buoyancy applied from the levitation stage section 3 while the chuck mechanism 51 sucks and holds the peripheral portion thereof. A thickness measuring sensor 61 is arranged near the roller conveyor 21 in order to detect the vertical position of the upper surface of the substrate W when the lower surface Wb of the substrate W is partially held by the chuck mechanism 51 . . A chuck (not shown) that does not hold the substrate W is positioned directly below the sensor 61, so that the sensor 61 can detect the vertical position of the upper surface of the attracting member, that is, the attracting surface.

The chuck mechanism 51 holds the substrate W transferred from the input transfer section 2 to the levitation stage section 3 . is transported to above the outlet floating stage 33 via above the coating stage 32 from the outlet. The transported substrate W is transferred to the output transfer section 4 arranged on the (+X) side of the exit floating stage 33 .

The output transfer section 4 includes a roller conveyor 41 and a rotation/elevation drive mechanism 42 having a function of rotating and elevating the roller conveyor 41 . As the roller conveyor 41 rotates, a driving force in the (+X) direction is applied to the substrate W, and the substrate W is further transported along the transport direction Dt. Further, the vertical position of the substrate W is changed as the roller conveyor 41 moves up and down. Actions realized by the vertical movement of the roller conveyor 41 will be described later. The substrate W is transferred from above the exit floating stage 33 to the output conveyor 110 by the output transfer section 4 .

The output conveyor 110 includes a roller conveyor 111 and a rotation driving mechanism 112 that rotates the conveyor. paid out to The input conveyor 100 and the output conveyor 110 may be provided as a part of the configuration of the coating device 1, or may be separate from the coating device 1. FIG. Further, for example, a substrate dispensing mechanism of another unit provided upstream of the coating apparatus 1 may be used as the input conveyor 100 . Alternatively, a substrate receiving mechanism of another unit provided downstream of the coating apparatus 1 may be used as the output conveyor 110 .

A coating mechanism 7 for coating the upper surface Wf of the substrate W with the processing liquid is arranged on the transport path of the substrate W transported in this way. The coating mechanism 7 has a nozzle 71 which is a slit nozzle. A processing liquid is supplied to the nozzle 71 from a processing liquid supply unit (not shown), and the processing liquid is discharged from a discharge port that opens downward at the bottom of the nozzle.

The nozzle 71 can be moved and positioned in the X and Z directions by a positioning mechanism 79 . The positioning mechanism 79 positions the nozzle 71 at the application position (the position indicated by the dotted line) above the application stage 32 . The processing liquid is discharged from the nozzle positioned at the coating position and coated on the substrate W conveyed between the coating stage 32 . In this way, the application of the processing liquid to the substrate W is performed.

A nozzle cleaning unit 8 is provided for performing a nozzle cleaning process on the nozzles 71 . The nozzle cleaning unit 8 includes a cleaning liquid storage tank 8b, a nozzle cleaner 8c, and a nozzle cleaning control mechanism 8d that controls the operations of the cleaning liquid storage tank 8b and the nozzle cleaner 8c.

When the nozzle 71 is located above the nozzle cleaner 8c (nozzle cleaning position), the nozzle cleaner 8c removes the processing liquid adhering to the periphery of the ejection port of the nozzle 71 . By performing the nozzle cleaning process on the nozzle 71 before it is moved to the coating position in this way, the discharge of the treatment liquid at the coating position can be stabilized from the initial stage. The detailed configuration of the nozzle 71 and the nozzle cleaner 8c, and the nozzle cleaning process of the nozzle 71 by the nozzle cleaner 8c will be described in detail later.

Further, the positioning mechanism 79 can position the nozzle 71 at a position (standby position) where the lower end of the nozzle comes into contact with the cleaning liquid stored in the cleaning liquid storage tank 8b. The nozzle 71 is positioned at this standby position when the coating process using the nozzle 71 is not executed. It should be noted that the lower end of the nozzle may be cleaned by applying ultrasonic waves to the cleaning liquid.

In addition, the coating device 1 is provided with a control unit 9 for controlling the operation of each part of the device. The control unit 9 includes a storage unit 91 for storing a predetermined control program and various data, a computing unit 92 such as a CPU that executes predetermined operations in each unit of the apparatus by executing the control program, and information exchange with users and external devices. and an interface unit 93 that is responsible for In the first embodiment, as will be described later, the computing unit 92 controls each part of the apparatus so that the moving speed of the nozzle cleaning member 81 with respect to the nozzles 71 is set to the first speed pattern (see FIG. 5 described later) suitable for nozzle cleaning. The nozzle cleaning process for the nozzles 71 is executed while controlling the acceleration and deceleration. That is, the computing section 92 functions as the "speed control section" of the present invention.

FIG. 2 is a perspective view of the nozzle viewed obliquely from below. In the same plane, the dimensions of the tip of the nozzle 71 to be cleaned are shown to be different from the actual size in order to clarify the configuration in the vicinity of the discharge port 71a of the nozzle 71 to be cleaned. This point also applies to FIG. 3 and the like, which will be described later.

The nozzle 71 has a shape extending in the Y direction as a whole, and includes a main body portion 711 fixedly supported by a nozzle support (not shown) and a lower end portion (“lip”) protruding downward from the main body portion 711 . (sometimes referred to as "part") 712. At the lower end of the lower end portion 712, a discharge port 71a, which is an elongated slit-shaped opening, extends in the Y direction. The ejection port 71a is open in an ejection port range shorter than the full length of the nozzle 71 in the Y direction. On the other hand, the ejection port 71a does not open at the central portion and both ends of the nozzle 71 in the Y direction, a notch portion 72 is provided at the central portion of the lower end portion 712, and an inclined portion 73 is provided at the (+Y) side of the lower end portion 712. In addition, a step portion 74 is provided on the (-Y) side. Therefore, the portions of the lower end portion 712 other than the cutout portion 72, the inclined portion 73 and the stepped portion 74 are protruding portions 75a and 75b, and the discharge port 71a is formed on the lower end surface of each of the protruding portions 75a and 75b. is provided. That is, in the nozzle 71, the protruding portions 75a and 75b protrude from the main body portion 711 by a fixed amount of protrusion. On the other hand, the notch portion 72 and the stepped portion 74 protrude from the main body portion 711 discontinuously as they advance in the extending direction Y, and are closer to the main body portion 711 than the protruding portions 75a and 75b. It is a part that recedes to In other words, these parts 72 and 74 correspond to an example of the "retracted part" of the present invention. On the other hand, the slant portion 73 retreats toward the main body portion 711 with the amount of protrusion from the main body portion 711 decreasing continuously from the amount of protrusion of the protruding portions 75a and 75b as it advances in the (+Y) direction.

The nozzle 71 has a configuration capable of ejecting the processing liquid from the ejection port 71a vertically downward, that is, in the (-Z) direction toward the upper surface Wf of the substrate W which is transported in the X direction while being levitated by the levitation stage section 3 . Specifically, when the treatment liquid is pressure-fed from a supply mechanism (not shown) to the nozzle 71, it is sent to the ejection port 71a via an internal flow path formed inside the main body 711, and the ejection port The ink is discharged from 71a in the (-Z) direction.

In addition, the symbols P1 to P5 in FIG. 2 are the following positions, that is,
Position P1: an inclined surface contact position where the scraper of the nozzle cleaner 8c, which will be described next, first contacts during the nozzle cleaning operation;
Position P2: a boundary position between the inclined portion 73 and the projecting portion 75a, and a cleaning start position where the nozzle cleaning operation of the projecting portion 75a by the nozzle cleaner 8c is started;
Position P3: a boundary position between the projecting portion 75a and the notch portion 72, and a cleaning end position where the nozzle cleaning operation of the projecting portion 75a by the nozzle cleaner 8c ends;
Position P4: a boundary position between the notch portion 72 and the projecting portion 75b, and a cleaning start position where the nozzle cleaning operation of the projecting portion 75b by the nozzle cleaner 8c is started;
Position P5: a boundary position between the protruding portion 75b and the stepped portion 74, and a cleaning end position where the nozzle cleaning operation of the protruding portion 75a by the nozzle cleaner 8c ends;
is shown.

FIG. 3 is a perspective view showing the configuration of the nozzle cleaner. The nozzle cleaner 8c includes a removing unit 8c1 that removes deposits adhering to the lower end portion (lip portion) 712 of the nozzle 71 by moving along with the nozzle cleaning member 81 in the cleaning direction Dc along the lower end portion (lip portion) 712 of the nozzle 71; and a moving part 8c2 for moving the unit 8c1 in the cleaning direction Dc. Here, the cleaning direction Dc means a direction parallel to the extending direction Y of the discharge port 71a and directed from the (+Y) side to the (−Y) side, and the moving part 8c2 reciprocates the removing unit 8c1 in the Y direction. It is possible to The processing liquid to be removed by the removing unit 8c1 includes various substances that can adhere to the lower end portion 712 of the nozzle 71. For example, there are dry and solidified solutes of the processing liquid. For example, when the processing liquid is a photoresist for color filters, the pigment contained in the processing liquid adheres to the lower end portion 712 of the nozzle 71 as the processing liquid.

Although not shown, the nozzle cleaner 8c includes a washing section and a rinse liquid supply section in addition to the removing unit 8c1 and the moving section 8c2 described above. The cleaning section cleans the nozzle cleaning member 81 inside a closed space formed by sealing the nozzle cleaning member 81 . That is, the cleaning unit supplies the cleaning liquid in the closed space to the nozzle cleaning member 81 from which the processing liquid adhering to the lower end portion 712 of the nozzle 71 has been removed by wiping it off. Wash off the liquid. As this cleaning unit, for example, the one described in Japanese Patent Application Laid-Open No. 2014-176812 can be used. Further, the rinse liquid supply section has a function of supplying the rinse liquid to the removal unit 8c1 through a flexible rinse liquid supply pipe whose tip is attached to the removal unit 8c1.

The removal unit 8c1 mainly includes a nozzle cleaning member 81 having a concave portion (substantially V-shaped V-shaped groove in the first embodiment) corresponding to the lower end portion 712 of the nozzle 71, and a support portion 82 that supports the nozzle cleaning member 81. have Note that FIG. 3 shows the configuration of the nozzle 71 and the removal unit 8c1 when the removal unit 8c1 is positioned further upstream in the cleaning direction Dc than the upstream end of the nozzle 71 in the cleaning direction Dc. .

The removal unit 8c1 has two types of nozzle cleaning members 81, a spreader 81A and a scraper 81B. Among these nozzle cleaning members 81 , the spreader 81 A has a function of supplying the rinse liquid to spread the rinse liquid over the lower end portion 712 of the nozzle 71 . On the other hand, the scraper 81B has a draining function of removing the rinse liquid from the lower end portion 712 of the nozzle 71 on the upstream side of the spreader 81A in the cleaning direction Dc, and corresponds to an example of the "nozzle contact member" of the present invention. . As a result, the processing liquid at the lower end portion 712 of the nozzle 71 can be removed together with the rinsing liquid. That is, when a processing liquid such as a dried and solidified processing liquid adheres to the lower end portion 712, the rinsing liquid spread by the spreader 81A dissolves the processing liquid to some extent, and the dissolved substance (processing liquid) is included. The rinse liquid is removed by scraper 81B. Thus, the nozzle cleaning member 81 uses the spreader 81A and the scraper 81B to perform the nozzle cleaning process of removing the processing liquid from the lower end portion 712 of the nozzle 71 . These spreader 81A and scraper 81B have the same outer shape except for the presence or absence of liquid supply holes (not shown) for supplying rinse liquid.

The nozzle cleaning member 81 is a plate-like member that can be supported by the supporting portion 82, and is made of an elastic material having an elastic modulus of, for example, 900 to 4000 MPa (megapascal). In this embodiment, the spreader 81A is made of a hard material that is harder than the scraper 81B. A center portion of the nozzle cleaning member 81 is supported by the support portion 82, and a V-shaped groove 811, which is a substantially V-shaped groove, is formed at the tip. The V-shaped groove 811 has a shape corresponding to the lower end portion 712 of the nozzle 71 .

Each nozzle cleaning member 81 configured in this way is detachably fixed to the support portion 82 by two fasteners, such as bolts, as shown in FIG. That is, the support portion 82 has an elevating portion 821 that can be raised and lowered in the Z direction, and two pillars 822A and 822B erected in the Z direction on the upper surface of the elevating portion 821 and arranged in the X direction. Among the pillars 822A and 822B, the spreader 81A is fastened to the upper end of the pillar 822A on the downstream side in the cleaning direction Dc, and the scraper 81B is fastened to the upper end of the pillar 822B on the upstream side in the cleaning direction Dc. It is Each nozzle cleaning member 81 has its V-shaped groove 811 directed toward the nozzle 71, and is inclined at a predetermined angle with respect to the nozzle 71 extending in the Y direction. signed by the Department. The top end of the column portion 822B is higher than the top end of the column portion 822A, and the scraper 81B is supported at a position higher than the spreader 81A.

The support portion 82 has a base portion 823 below the elevating portion 821 to which each nozzle cleaning member 81 is fixed. The elevating portion 821 is supported by the base portion 823 so as to be able to ascend and descend. That is, in the support portion 82, a guide rail 824 erected from the upper surface of the base portion 823 in the Z direction, and an urging member 825 (for example, a compression spring) provided between the base portion 823 and the lifting portion 821. is provided. While the guide rail 824 guides the movement of the lifting section 821 in the Z direction, the biasing member 825 biases the lifting section 821 upward with respect to the base section 823 . Therefore, each nozzle cleaning member 81 fixed to the lifting portion 821 is urged upward by the urging force of the urging member 825 .

Also, the base portion 823 of the support portion 82 is attached to the moving portion 8c2. This moving part 8c2 has a pair of rollers 851, 851 arranged on both sides of the nozzle 71 in the Y direction, and an endless belt 852 stretched over the rollers 851, 851, and is supported on the upper surface of the endless belt 852. A base portion 823 of portion 82 is attached. The moving part 8c2 configured in this way rotates the rollers 851, 851 to drive the upper surface of the endless belt 852 in the Y direction, and moves the nozzle cleaning members 81 in the Y direction along with the supporting part 82. The configuration of the moving part 8c2 is not limited to this, and a moving part of, for example, a ball screw system or a linear motor system can be used.

When the nozzle cleaner 8c configured as described above brings each nozzle cleaning member 81 close to the lower end portion 712 of the nozzle 71 located at the inclined surface contact position P1 corresponding to the nozzle cleaning position, from below, Only the scraper 81B of the nozzle cleaning member 81 contacts the inclined surface 731 of the nozzle 71 and is pressed by the biasing member 825 . That is, the V-shaped groove 811 of the scraper 81B contacts the nozzle 71. As shown in FIG.

FIG. 4 is a flow chart showing an example of nozzle cleaning processing by the nozzle cleaner, which is the first embodiment of the nozzle cleaning device according to the present invention. FIG. 5 is a diagram schematically showing part of the operations performed according to the flowchart of FIG. In FIG. 5, the spreader 81A is omitted in order to clarify the position and movement speed of the scraper 81B corresponding to the "nozzle contact member" of the present invention, and the position of the scraper 81B is the first position of the nozzle cleaning member 81. It is illustrated in association with a graph showing speed patterns.

In the coating apparatus 1, the cleaning operation of the nozzles 71 is performed by the operation section 92 controlling each section of the apparatus as follows according to the control program stored in the storage section 91 of the control unit 9. FIG.

In step S1, the removal unit 8c1 is driven by the moving part 8c2 to move to the inclined surface contact position P1. As a result, the removing unit 8c1 is positioned below the inclined portion 73 of the nozzle 71 positioned at the inclined surface contact position P1, and the spreader 81A and the scraper 81B face the inclined surface 731 of the inclined portion 73 from below. At this point, both the spreader 81A and the scraper 81B are located upstream of the projecting portions 75a and 75b having the discharge port 71a in the cleaning direction Dc. Further, in step S1, the inclined portion 73 of the nozzle 71, the spreader 81A and the scraper 81B are separated in the Z direction.

When the movement of the removing unit 8c1 to the inclined surface contact position P1 is thus completed, the nozzle 71 ejects a predetermined amount of processing liquid from the ejection port 71a (step S2). One of the main purposes of the ejection of the treatment liquid here is to discharge the air and the cleaning liquid that have partially entered the ejection port 71a. Therefore, the processing liquid is ejected from the ejection port 71a to the extent that it slightly protrudes downward.

In the next step S3, the nozzle 71 descends to a lower position lower than the upper position. Specifically, when the nozzle 71 starts to descend, the distance between the inclined portion 73 of the nozzle 71 and the scraper 81B is reduced, and the lip side surface of the lower end portion 712 and the recessed portion of the scraper 81B come into contact with each other at the inclined portion 73 . The nozzle 71 descends further and pushes the scraper 81B downward against the biasing force of the biasing member 825 . Also, the spreader 81A moves downward together with the scraper 81B while maintaining a constant distance between the recess and the lip side surface. Thus, the concave portion of the scraper 81B is pressed against the lip side surface by the biasing force of the biasing member 825 at the inclined portion 73 . That is, the scraper 81B contacts the lower end portion 712 of the nozzle 71 (timing T10). At this time, a constant space is secured between the recess of the spreader 81A and the lip side surface.

When the descent of the nozzle 71 is completed in this way, the rinse liquid is discharged from the liquid supply hole (not shown) of the spreader 81A, and the supply of the rinse liquid between the inclined portion 73 of the nozzle 71 and the spreader 81A is started (step S4). In the first embodiment, not only the treatment liquid is discharged, but also the rinse liquid is discharged. This is because the scraper 81B moves at a high speed. In other words, it is possible to use the treatment liquid as a lubricating liquid when the scraper 81B cleans the nozzles, but if the scraper 81B moves at a high speed at that time, it becomes difficult to obtain a sufficient lubricating effect with only the treatment liquid. Sometimes. Therefore, in the first embodiment, in order to shorten the time required for the nozzle cleaning process by increasing the moving speed of the scraper 81B, both the treatment liquid and the rinse liquid are used as lubricants during the nozzle cleaning process. However, the discharge amount of the rinse liquid is suppressed to a certain level or less. More specifically, a mixture of the rinse liquid and the treatment liquid (a treatment liquid diluted with the rinse liquid to an extent that does not affect the coating process) or only the treatment liquid is applied to the ejection openings 71a after the nozzle cleaning process. It is preferable to adjust the supply amount (discharge amount) of the rinse liquid per unit time so as to remain. Various liquids can be used as the rinsing liquid. For example, the rinsing liquid may be a solvent that composes the treatment liquid. In this case, a solution obtained by dissolving the solute in the rinsing liquid, which is the solvent, becomes the treatment liquid.

Subsequently, the moving part 8c2 drives the removing unit 8c1 in the cleaning direction Dc, thereby starting member moving operation for moving the spreader 81A and the scraper 81B in the cleaning direction Dc (step S5). In the initial stage of this member moving operation, the scraper 81B is gradually pushed down against the biasing force of the biasing member 825 along the inclined surface 731 and moves together with the spreader 81A toward the projecting portions 75a and 75b. The spreader 81A and the scraper 81B have the same positional relationship as the inclined surface 731 even when they are moved to the projecting portions 75a and 75b. In other words, since the spreader 81A and the scraper 81B are positioned to abut on the lip side surface, a gap is formed between each of the spreader 81A and the scraper 81B and the tip surfaces of the projecting portions 75a and 75b. Each of spreader 81A and scraper 81B does not contact the tip surface. However, if the concave portion of the scraper 81B contacts the lip side surface, the scraper 81B may be configured to contact the tip end surface.

The scraper 81B is moved in the cleaning direction Dc parallel to the Y direction together with the spreader 81A at the first speed pattern from the inclined surface contact position P1, as will be described in detail below (step S5). Even after this movement is started, the supply of the rinse liquid from the liquid supply holes is continued while the nozzle cleaning member 81 (=spreader 81A+scraper 81B) is moving in the cleaning direction Dc.

As shown in FIG. 5, the movement of the nozzle cleaning member 81 is started at timing T10, and its moving speed is increased at a constant acceleration α11. At timing T11, the moving speed of the nozzle cleaning member 81 reaches the preset first moving speed V1, and the scraper 81B moves at the first moving speed V1 along the boundary position P2 between the inclined portion 73 and the projecting portion 75a. do. Acceleration is stopped from timing T11, and the moving speed of the nozzle cleaning member 81 is maintained at the first moving speed V1 while the scraper 81B moves along the projecting portion 75a, that is, from timing T11 to timing T12. Thus, the projecting portion 75a is cleaned by the nozzle cleaning member 81 that moves in the cleaning direction Dc at the constant first moving speed V1.

At timing T12, the scraper 81B reaches the boundary position P3 between the projecting portion 75a and the notch portion 72. As shown in FIG. Here, if the nozzle cleaning member 81 is moved to the notch portion 72 at the first moving speed V1 as it is in the same manner as in the conventional technology, the corner formed by the inner wall and the inner bottom surface on the (+Y) direction side of the notch portion 72 A large amount of part of the treatment liquid scraped by the scraper 81B remains on the part. As a result, the problems described above occur.

Therefore, in the first embodiment, as shown in the graph of FIG. 5, the moving speed of the nozzle cleaning member 81 is decelerated ( Negative acceleration) decelerate at α12. As a result, the amount of processing liquid remaining in the corner portion (hereinafter referred to as "residual amount") is greatly reduced.

In the first embodiment, after the scraper 81B passes through the cutout portion 72, it is necessary to clean the projecting portion 75b in the same manner as the projecting portion 75a. is switching to More specifically, the moving speed of the nozzle cleaning member 81 is increased at the acceleration α13 from timing T13, and when the scraper 81B reaches the boundary position P4 between the notch portion 72 and the projecting portion 75b (timing T14), the scraper 81B is moved. The speed control unit of the calculation unit 92 performs control so that the moving speed of V returns to the original first moving speed V1.

Acceleration is stopped from this timing T14, and the movement speed of the nozzle cleaning member 81 is maintained at the first movement speed V1 while the scraper 81B is moving along the projecting portion 75b, that is, from timing T14 to timing T15. Thus, the projecting portion 75b is cleaned by the nozzle cleaning member 81 that moves in the cleaning direction Dc at the constant first moving speed V1.

At timing T15, the scraper 81B reaches the boundary position P5 between the projecting portion 75b and the stepped portion 74. As shown in FIG. In the prior art, as indicated by the dashed line in the graph of FIG. 5, after the scraper 81B passes through the boundary position P5 and moves a certain distance, the scraper 81B moves from the inclined surface contact position P1 to the boundary position P2. The movement of the nozzle cleaning member 81 is stopped by decelerating at a deceleration (negative acceleration) of about the same magnitude as when the nozzle cleaning member 81 is moved to . Therefore, a large amount of the treatment liquid scraped by the scraper 81B remains even at the stepped portion 74 . As a result, the problems described above occur.

Therefore, in the first embodiment, as shown in the graph of FIG. 5, the moving speed of the nozzle cleaning member 81 is decelerated from the first moving speed V1 ( Deceleration at negative acceleration) α14 stops the movement of the nozzle cleaning member 81 when the spreader 81A and the scraper 81B are downstream of the nozzle 71 in the cleaning direction Dc (step S6). As a result, the residual amount of the processing liquid at the step portion 74 is greatly reduced. At the same time when the movement of the nozzle cleaning member 81 is stopped, the supply of the rinse liquid from the liquid supply holes is stopped (step S7).

When the nozzle cleaning process for the nozzle 71 is completed in this way, the positioning mechanism 79 moves the nozzle 71 to the coating position above the coating stage 32 (the position indicated by the dotted line in FIG. 1). Then, the processing liquid is discharged from the nozzle positioned at the coating position, and coated onto the substrate W conveyed between the coating stage 32 (coating step).

In the first embodiment configured as described above, when the scraper 81B passes through the boundary positions P3 and P5, the relative movement speed of the scraper 81B with respect to the nozzle 71 is reduced below the first movement speed V1. The speed control section of the calculation section 92 controls. As a result, the amount of processing liquid remaining in the notch portion 72 and the stepped portion 74 can be greatly reduced.

Also, the absolute value of the acceleration α12 of the scraper 81B when the scraper 81B moves from the projecting portion 75a to the notch portion 72 is the absolute value of the acceleration α13 of the scraper 81B when the scraper 81B moves from the notch portion 72 to the projecting portion 75b. is smaller than That is, the moving speed of the scraper 81B to the corner portion is gradually reduced, and the followability of the scraper 81B can be improved. As a result, the residual amount at the corner portion can be reliably suppressed.

By the way, in the above embodiment, the scraper 81B is made of an elastic material. Therefore, the scraper 81B bends according to the relative movement of the scraper 81B in a state where the recess of the scraper 81B is in contact with the nozzle 71. As shown in FIG. Also, the scraper 81B returns to its original shape when the contact with the lower end portion 712 is released. Therefore, the speed pattern of the scraper 81B may be changed from the first speed pattern in consideration of the elastic characteristics of the scraper 81B (second embodiment).

FIG. 6 is a diagram schematically showing part of the operation performed in the second embodiment of the nozzle cleaning device according to the present invention. The major difference between the second embodiment and the first embodiment is the moving speed when the scraper 81B passes through the positions P2, P3, and P5, and other points are the same as those of the first embodiment. In the following, the description will focus on the differences, and the same or equivalent reference numerals will be assigned to the same configurations, and the description will be omitted.

In the second embodiment, the acceleration from when the nozzle cleaning member 81 starts moving until it reaches the first moving speed V1 is set to an acceleration α21 that is smaller than the acceleration α11 in the first embodiment. Also, the scraper 81B is set to reach the first moving speed V1 when it has slightly passed the boundary position P2 between the inclined portion 73 and the projecting portion 75a (timing T21). Therefore, the scraper 81B gradually bends while sliding on the inclined surface 731, although the scraper 81B starts cleaning the projecting portion 75a later than in the first embodiment. In this manner, the scraper 81B conforms to the lower end portion 712 of the nozzle 71 following the movement of the nozzle cleaning member 81. As shown in FIG. As a result, it is possible to improve the scraping performance of the processing liquid from the lower end portion 712 before and after the boundary position P2 as compared with the first embodiment. Also, by keeping the acceleration α21 (<α11) low, it is possible to reduce the size of the motor for rotating the rollers 851, 851 of the moving portion 8c2.

Further, after the timing T21, the nozzle cleaning process for the projecting portion 75a is executed while the scraper 81B is bent, but the scraper 81B reaches the position immediately before the boundary position P3 between the projecting portion 75a and the notch portion 72. The deceleration of the nozzle cleaning member 81 is started from timing T22. That is, the start of deceleration in the second embodiment is earlier than in the first embodiment. As a result, the following effects can be obtained. The amount of deformation of the scraper 81B varies depending on the change in moving speed and the contacting portion. In particular, in the first embodiment, the scraper 81B moving at the first moving speed V1 is rapidly decelerated when it reaches the boundary position P3. Further, the contact point of the scraper 81B greatly changes from the projecting portion 75a to the notch portion 72 with the boundary position P3 as a boundary. Therefore, in the first embodiment, the scraper 81B is greatly deformed as soon as the notch portion 72 is cleaned, and it is difficult to control the bending state of the scraper 81B following the shape of the notch portion 72. There is In contrast, in the second embodiment, the scraper 81B starts decelerating at the timing T22 immediately before the scraper 81B reaches the boundary position P3. can be made to follow the shape of the notch portion 72 . As a result, the cleaning performance of the notch portion 72 can be improved more than in the first embodiment.

Furthermore, the deceleration of the nozzle cleaning member 81 is started at timing T25 when the scraper 81B reaches the position immediately before the boundary position P5 between the projecting portion 75b and the step portion 74. FIG. As a result, the same effect as the deceleration start at the timing T22, that is, the bending state of the scraper 81B can follow the shape of the stepped portion 74, and the cleaning performance of the stepped portion 74 can be improved compared to the first embodiment. can be done.

As described above, in the first embodiment and the second embodiment, the notch portion 72 and the stepped portion 74 protrude downward from the main body portion 711 in the cleaning direction (extending direction) Dc, and the amount of protrusion is discontinuous. It corresponds to an example of the "retracted portion" of the present invention, which is retracted to the main body portion 711 side by a reduction in amount of projection compared to that of the projecting portions 75a and 75b.

The present invention is not limited to the above-described embodiments, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, in the first and second embodiments, the nozzle 71 having the stepped portion 74 at the rear end of the lower end 712 in the cleaning direction Dc is cleaned, but application of the present invention is not limited to this. For example, as shown in FIG. 7, the present invention can be applied to a nozzle cleaning device (third embodiment) that cleans a nozzle 71 provided with an inclined portion 76 instead of a stepped portion 74 . Here, the slant portion 76 is retreated toward the main body portion 711 as the amount of protrusion downward from the main portion 711 is continuously reduced as compared with the protruding portions 75a and 75b as it advances in the cleaning direction Dc. It is meant to have an inclined surface 761 . In this third embodiment, the inclined portion 76 corresponds to an example of the "retracted portion" of the present invention.

In the above embodiment, the present invention is applied to the nozzle cleaning device for cleaning the nozzle 71 having only one notch portion 72 provided at the center of the lower end portion 712. However, the number of the notch portions 72 is The present invention is not limited to this, and the present invention can be applied to a nozzle cleaning apparatus for cleaning two or more nozzles or a nozzle having a notched portion.

Further, in the above embodiment, the present invention is applied to the nozzle cleaning device equipped with the spreader 81A in addition to the scraper 81B, but the present invention can also be applied to the nozzle cleaning device equipped with only the scraper 81B. can be done.

INDUSTRIAL APPLICABILITY The present invention can be applied to general nozzle cleaning techniques for cleaning the nozzles by removing treatment liquid adhering to the lower end of the nozzles with a nozzle contact member, and general coating apparatuses equipped with the nozzle cleaning techniques. .

DESCRIPTION OF SYMBOLS 1... Coating device 8... Nozzle cleaning unit 8c... Nozzle cleaner (nozzle cleaning device)
8c2... Moving portion 71a... Discharge port 72... Notch portion (retracted portion)
74 ... Step part (retreat part)
75a, 75b... Protruding part 76... Inclined part (retracted part)
81 Nozzle cleaning member 81B Scraper (noise contact member)
92... Arithmetic unit (speed control unit)
711 Main body portion (of nozzle) 712 Lower end portion (of nozzle) Dc Washing direction (extending direction)
P2, P3, P5... Boundary position V1... First moving speed W... Substrate Y... Extending direction

Claims (7)

A nozzle cleaning device for cleaning a nozzle that ejects a processing liquid from a slit-shaped ejection port provided at a lower end projecting downward from a main body of the nozzle,
a nozzle abutment member capable of abutting against the lower end of the nozzle;
a moving unit that moves the nozzle contact member relative to the nozzle in the extending direction of the discharge port while keeping the nozzle contact member in contact with the lower end of the nozzle;
a speed control unit that controls the moving speed of the nozzle contact member by the moving unit;
The lower end portion includes a projecting portion projecting downward from the main body portion and having a constant projecting amount, and the projecting amount is continuously or discontinuously greater than the projecting amount of the projecting portion as the extending direction progresses. and a receding portion that recedes toward the main body side by decreasing the
The nozzle contact member that is moved relative to the nozzle by the moving section moves the projecting portion, moves from the projecting portion to the retracted portion, and moves the retracted portion. , continues to abut against the lower end of the nozzle,
The speed control unit moves the nozzle contact member at a first movement speed at the projecting portion, and moves the nozzle contact member when the nozzle contact member moves from the projecting portion to the retreating portion. A nozzle cleaning device characterized in that the speed is reduced from the first moving speed. The nozzle cleaning device according to claim 1,
The nozzle contact member has elasticity, is bent by contact with the lower end portion, and returns to its original shape when the contact with the lower end portion is released. The nozzle cleaning device according to claim 2,
The nozzle cleaning device, wherein the speed control section starts decelerating the nozzle contact member immediately before the nozzle contact member moves from the projecting portion to the retreating portion. The nozzle cleaning device according to claim 2 or 3,
The nozzle cleaning device, wherein the recessed portion is a notch portion formed in the center portion of the lower end portion of the nozzle in the extending direction. The nozzle cleaning device according to claim 4,
the nozzle contact member moved relative to the nozzle by the moving part continues to contact the lower end of the nozzle when moving from the retracted portion to the projecting portion;
The ejection port is provided only at the projecting portion,
The speed control unit
increasing the movement speed of the nozzle contact member to the first movement speed when the nozzle contact member moves from the retracted portion to the projecting portion;
The absolute value of the acceleration of the nozzle contact member when the nozzle contact member moves from the projecting portion to the retracted portion is calculated as the nozzle contact member when the nozzle contact member moves from the retracted portion to the projecting portion. A nozzle cleaning device that reduces the absolute value of the acceleration of a contact member. A nozzle cleaning method for cleaning a nozzle that ejects a processing liquid from a slit-shaped ejection port provided at a lower end projecting downward from a main body of the nozzle, comprising:
a first step of bringing a nozzle contact member into contact with the lower end of the nozzle;
a second step of moving the nozzle contact member relative to the nozzle in the extending direction of the discharge port while keeping the nozzle contact member in contact with the lower end portion;
The second step is
a constant-velocity moving step of moving the nozzle contact member at a first moving speed at a protruding portion of the lower end portion that protrudes downward from the main body portion by a constant amount;

The nozzle abuts from the projecting portion to the retreating portion, in which the amount of projection decreases continuously or discontinuously as the projecting portion advances in the extension direction, and retreats toward the main body portion. a deceleration movement step of decelerating the movement speed of the nozzle contact member from the first movement speed when the member moves ;
The constant-velocity movement step and the deceleration movement step are performed when the nozzle contact member moved relative to the nozzle moves in the projecting portion, when moving from the projecting portion to the retreating portion, and while moving the retracted portion while continuing to abut on the lower end of the nozzle
A nozzle cleaning method characterized by: a nozzle for supplying a processing liquid to a substrate by discharging it from a slit-shaped discharge port provided at a lower end projecting downward from a main body of the nozzle;
a nozzle cleaning device according to any one of claims 1 to 5;
A coating device comprising:

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