JP5619536B2 - Application method and apparatus - Google Patents

Description

  The present invention relates to a coating method and apparatus.

  In a manufacturing process of a liquid crystal display device or the like, an ink jet type coating apparatus for forming a functional thin film on a substrate is used in a film forming process for forming a circuit pattern on a glass substrate.

  As described in Patent Document 1, the coating apparatus moves the coating head relative to the substrate, and the liquid droplets continuously ejected from a plurality of nozzles provided in the coating head with respect to the substrate are in the relative movement direction described above. Apply along.

JP2003-94631

  By the way, in the coating apparatus described in Patent Document 1, a piezoelectric element facing each nozzle of the coating head is provided via a flexible plate. When a voltage is applied to the piezoelectric element, the flexible plate is deformed and droplets are ejected from the corresponding nozzle. Even if the same voltage is applied to the individual piezoelectric elements facing each nozzle, each nozzle has different discharge characteristics depending on the piping resistance from the supply source of the coating liquid, manufacturing accuracy, assembly accuracy, etc. A difference may occur in the discharge amount of the liquid. In that case, unevenness occurs in the coating film formed on the substrate, and the thickness of the functional thin film is not uniform.

  Therefore, in the conventional coating apparatus, the droplet discharge amount from each nozzle of the coating head is measured so that the actual discharge amount of the droplet from each nozzle matches the same set discharge amount with high accuracy. The magnitude of the voltage applied to the piezoelectric element corresponding to each nozzle is finely adjusted with high accuracy based on the measurement result of the discharge amount.

  However, the coating head is provided with several tens to several hundreds of nozzles, and it is not easy to finely adjust the magnitude of the voltage applied to the corresponding piezoelectric element for each of the many nozzles. In addition to the time required for the adjustment, the control device is increased in size, increased in heat generation, and increased in cost.

  An object of the present invention is to easily eliminate unevenness of a coating film caused by a difference in the amount of droplets discharged from each nozzle of a coating head.

Coating method according to the embodiment, while relatively moving the coating head and the substrate, in the coating method of applying the droplets ejected from a plurality of nozzles provided in the coating head to a substrate,
For each nozzle of the coating head, droplets are ejected with a basic ejection pattern consisting of a combination of droplets with different ejection amounts,
When the amount of droplets for a plurality of droplets continuously discharged from one nozzle is different from the required amount, the combination of droplets with different discharge amounts in the basic discharge pattern of this nozzle can be changed. Features.
An application method according to an embodiment is an application method in which droplets ejected from a plurality of nozzles provided in the application head are applied to the substrate along the relative movement direction while the application head and the substrate are relatively moved. In
For each nozzle of the coating head, to eject droplets basic ejection pattern consisting of a combination of a plurality of types of droplets having different sizes, droplet of each of the nozzles when ejecting droplets by the basic discharge pattern The average discharge amount and the theoretical average discharge amount of the droplets to be discharged from the nozzle with the basic discharge pattern are compared, and if there is a nozzle having a different average discharge amount and the theoretical average discharge amount, The combination of droplets in the basic discharge pattern is changed so that the average discharge amount from the nozzle becomes the theoretical average discharge amount.

An application method according to an embodiment is an application method in which droplets ejected from a plurality of nozzles provided in the application head are applied to the substrate along the relative movement direction while the application head and the substrate are relatively moved. In
For each nozzle of the coating head, droplets are ejected in a basic ejection pattern consisting of a combination of a plurality of types of droplets having different sizes, and droplets ejected from the nozzles in a basic ejection pattern and applied onto the substrate If there is unevenness in the coating film formed by the above , the combination of droplets in the basic discharge pattern of the droplets discharged from the nozzle corresponding to the uneven portion is changed so as to eliminate the unevenness of the coating film. And

The coating apparatus according to the embodiment includes a coating head including a plurality of nozzles, and a control device capable of controlling the discharge amount of droplets discharged from each nozzle of the coating head to different discharge amounts. In a coating apparatus that applies the droplets discharged from the plurality of nozzles to the substrate while relatively moving the coating head and the substrate,
The control device discharges droplets with a basic discharge pattern composed of a combination of droplets having different discharge amounts for each nozzle of the coating head, and drops a plurality of droplets continuously discharged from one nozzle. When the amount is different from the required amount, the combination of droplets of different discharge amounts in the basic discharge pattern of the nozzle is changed .
The coating apparatus according to the embodiment includes a coating head having a plurality of nozzles, a discharge amount measuring apparatus that measures a discharge amount of droplets from each nozzle of the coating head, and a droplet from each nozzle of the coating head. And a controller for controlling the discharge amount of the liquid droplets, and applying the liquid droplets discharged from the plurality of nozzles along the relative movement direction to the substrate while relatively moving the coating head and the substrate. In the coating device,
The controller is
For each nozzle of the coating head, to eject droplets basic ejection pattern consisting of a combination of a plurality of types of droplets having different sizes, droplet of each of the nozzles when ejecting droplets by the basic discharge pattern The average discharge amount and the theoretical average discharge amount of the droplets to be discharged from the nozzle with the basic discharge pattern are compared, and if there is a nozzle having a different average discharge amount and the theoretical average discharge amount, wherein the average discharge rate from the nozzle to change the combination of the droplets in the basic discharge pattern so as to the theoretical average discharge amount.

An application apparatus according to an embodiment includes an application head including a plurality of nozzles, and a control device that controls a discharge amount of liquid droplets from each nozzle of the application head, and the application head and the substrate are relative to each other. In the coating apparatus for applying the liquid droplets discharged from the plurality of nozzles along the relative movement direction to the substrate while being moved,
The controller is
For each nozzle of the coating head, droplets are ejected in a basic ejection pattern consisting of a combination of a plurality of types of droplets having different sizes, and droplets ejected from the nozzles in a basic ejection pattern and applied onto the substrate If there is unevenness in the coating film formed by the above , the combination of droplets in the basic discharge pattern of the droplets discharged from the nozzle corresponding to the uneven portion is changed so as to eliminate the unevenness of the coating film. And

  According to the present invention, it is possible to easily eliminate the unevenness of the coating film caused by the difference in the amount of droplets discharged from each nozzle of the coating head.

FIG. 1 is a front view showing a coating apparatus. FIG. 2 is a plan view showing the coating apparatus. FIG. 3 is a side view showing the coating apparatus. FIG. 4 is a block diagram showing a control system of the coating apparatus. FIG. 5 is a circuit diagram showing an example of a piezoelectric element driving circuit. FIG. 6 is a circuit diagram showing another example of the piezoelectric element driving circuit. FIG. 7 is a schematic diagram showing a droplet discharge pattern. FIG. 8 is a diagram showing the measurement results of the average discharge amount from each of the 64 nozzles.

  1 to 3 includes a substrate stage 13 mounted on a Y-axis direction moving guide 12 on the upper surface of a base 11, and the substrate stage 13 is moved in the Y-axis direction by a Y-axis direction moving actuator (not shown). to enable. On the substrate stage 13, a glass substrate 1 used for manufacturing a liquid crystal display device is placed.

  The coating apparatus 10 is provided with a portal frame 14 straddling the Y-axis direction moving guide 12 at a substantially central portion in the Y-axis direction on the upper surface of the base 11, and a plurality of (this embodiment) is provided on the frame body 15 on the front surface of the portal frame 14. In the example, three coating heads 20 are arranged in a staggered manner along the X-axis direction orthogonal to the Y-axis direction, as shown in FIG.

  The coating head 20 is a functional thin film formed by an ink jet method, for example, a plurality of nozzles that discharge droplets of a coating liquid (polyimide solution) for forming an alignment film is arranged at predetermined intervals along the X-axis direction. doing. The coating head 20 is provided with a piezoelectric element that faces each nozzle through a flexible plate, deforms the flexible plate by applying a voltage to each piezoelectric element, and applies droplets of coating liquid from the corresponding nozzle. Discharge.

  The coating apparatus 10 moves the substrate stage 13 on which the substrate 1 is placed in the Y-axis direction, thereby moving the coating head 20 relative to the substrate 1 and facing each nozzle provided in the coating head 20. By simultaneously applying a voltage to the element at a preset frequency, droplets continuously ejected from each nozzle are applied to the substrate 1 along the relative movement direction. The liquid droplets discharged from each nozzle wet and spread on the substrate 1 and combine with adjacent liquid droplets to form a coating film.

  The coating apparatus 10 includes a discharge amount measuring device 30 that measures the discharge amount of droplets from each nozzle of the coating head 20. The discharge amount measuring device 30 includes an X-axis moving device 33 mounted on an X-axis direction moving guide 32 on the upper surface of the mounting bracket 31 fixed to the Y-axis direction end surface (the right end surface in FIG. 1) of the substrate stage 13, and is not shown. The X-axis moving device 33 can be moved in the X-axis direction by an X-axis direction moving actuator. A lifting device 34 is mounted on the upper surface of the X-axis moving device 33, and a discharge table 35 is installed on the lifting device 34. The discharge amount measuring device 30 can mount the containers 36 (four in the example of FIGS. 1 to 3) provided on one coating head 20 on the discharge table 35.

  The discharge amount measuring device 30 moves the substrate stage 13 in the Y-axis direction to the position indicated by the broken line in FIG. 1 when storing the coating liquid in each container 36, so that each container 36 is directly below the coating head 20 in the Y-axis direction. Position. Simultaneously with or following this operation, the X-axis moving device 33 is driven, and each container 36 is positioned at one of the three coating heads 20, for example, one end in the X-axis direction. Directly below the coating head 20, each nozzle of the coating head 20 and each container 36 are positioned so as to face each other vertically.

  The discharge amount measuring device 30 drives the lifting device 34 while positioning each container 36 directly below the coating head 20, raises each container 36 together with the discharge table 35, and places each container 36 on the nozzle formation surface of the coating head 20. The upper ends are brought close to each other (indicated by a broken line in FIG. 3). In this state, the piezoelectric elements of all (four) nozzles of the coating head 20 are driven simultaneously, and droplets of the coating liquid are repeatedly ejected from each nozzle at the same time for a unit time, in other words, a preset number of ejections. The coating liquid is stored in each container 36. When the discharge of the coating liquid from the coating head 20 is completed, the substrate stage 13 is returned to the position shown by the solid line in FIGS. 1 and 2, and each container 36 is taken out from the discharge table 35. In the discharge amount measuring device 30, the weight of each container 36 is individually measured with a weighing scale such as an electronic balance (not shown), and the empty weight of the container 36 is subtracted from the measured value, whereby each container 36 is The total discharge amount corresponding to the preset number of discharges (droplet number) of the droplets stored from each nozzle can be measured. By dividing this total discharge amount by the number of discharges (number of droplets) of the nozzle, the average discharge amount of droplets from the nozzle can be measured.

  However, the coating apparatus 10 has the following configuration in order to easily eliminate unevenness of the coating film due to the difference in the discharge amount of droplets from each nozzle of the coating head 20.

  As shown in FIG. 4, the coating apparatus 10 includes a control device 40 that controls the amount of droplets discharged from each nozzle of the coating head 20. The control device 40 performs a control operation as follows.

  (1) The control device 40 controls the increase / decrease of the discharge amount for each nozzle of the coating head 20 to control a plurality of types of droplets discharged from each nozzle, which are large droplets or small droplets in this embodiment. It is possible to control to two types.

  That is, the control device 40 uses a piezoelectric element drive circuit 41 that controls a voltage applied to each piezoelectric element facing each nozzle of the coating head 20 via a flexible plate. The control device 40 controls, for example, a voltage applied to the piezoelectric element 23 to a large voltage V1 and a small voltage V2 using a piezoelectric element drive circuit 41 shown in FIG. 5, and the nozzle to which the piezoelectric element 23 to which the large voltage V1 is applied is opposed. The large droplet A is discharged from the nozzle, and the small droplet B is discharged from the nozzle facing the piezoelectric element 23 to which the small voltage V2 is applied. Note that the piezoelectric element drive circuit 41 in FIG. 5 shows two piezoelectric elements 23 facing the two nozzles. However, the piezoelectric element drive circuit 41 individually controls the voltage applied to the number of piezoelectric elements 23 facing the respective nozzles.

  The piezoelectric element drive circuit 41 shown in FIG. 5 has a power supply P1 with a large voltage V1 and a power supply P2 with a small voltage V2. The emitter terminal of the transistor T1 is connected to the power source P1, the emitter terminal of the transistor T2 is connected to the power source P2, and the input terminal of the piezoelectric element 23 is connected to the collector terminals of the transistors T1, T2, and T3. When a large voltage V1 is applied to the piezoelectric element 23 by turning on the transistor T1 by the signal D1 from the control unit C, the piezoelectric element is greatly contracted, and then the transistor T1 is turned off and the transistor T3 is turned on by the signal D3. As a result, the piezoelectric element 23 is restored, and a droplet discharged from the nozzle facing the piezoelectric element 23 is referred to as a large droplet A. Similarly, when a small voltage V2 is applied to the piezoelectric element 23 by turning on the transistor T2 by the signal D2 from the control unit C, the piezoelectric element 23 contracts to a small extent, and then the transistor T2 is turned off, and the signal D3 By turning on the transistor T3, the piezoelectric element 23 is restored, and a droplet ejected from a nozzle facing the piezoelectric element 23 is referred to as a small droplet B.

  The piezoelectric element driving circuit 41 shown in FIG. 6 can generate a large voltage V1 and a small voltage V2 by a voltage Vd (Vd can be adjusted by an external command) of a single power source P. That is, the emitter terminal of the transistor T1 is connected to the power source P through the resistor Z1, the emitter terminal of the transistor T2 is connected to the power source P through the resistor Z2 (Z2 ≠ Z1), and each of the transistors T1, T2, and T3 is connected. The resistor Z3 and the input end of the piezoelectric element 23 are connected in parallel to the collector terminal. When the transistor T1 is turned on by the signal D1 from the control unit C, when the large voltage V1 (V1 = Vd × [Z3 / (Z1 · Z3)]) is applied to the piezoelectric element 23, the piezoelectric element 23 is greatly contracted, Subsequently, the transistor T1 is turned off and the transistor T3 is turned on by the signal D3, whereby the piezoelectric element 23 is restored, and a droplet ejected from the nozzle facing the piezoelectric element 23 is referred to as a large droplet A. Similarly, when a small voltage V2 (V2 = Vd × [Z3 / (Z2 · Z3)]) is applied to the piezoelectric element 23 by turning on the transistor T2 by the signal D2 from the control unit C, the piezoelectric element 23 is The piezoelectric element 23 is restored by shrinking to a small extent and subsequently turning off the transistor T2 and turning on the transistor T3 with the signal D3. The droplets ejected from the nozzle facing the piezoelectric element 23 are referred to as small droplets B. To do.

  Note that the piezoelectric element drive circuit 41 of FIG. 6 shows only one piezoelectric element 23 facing one nozzle. However, the piezoelectric element drive circuit 41 individually controls the voltage applied to the number of piezoelectric elements 23 facing the respective nozzles.

  (2) The control device 40 determines a basic ejection pattern in which droplets continuously ejected from each nozzle of the coating head 20 are combined with a specific type over time.

  For example, as shown in FIG. 7A, this basic ejection pattern is a combination of large droplets A and small droplets B over time, with two droplets [large droplet A and small droplet B] in this order. It is possible to repeat patterns arranged alternately.

  (3) The control device 40 controls the voltage applied to the piezoelectric element facing each nozzle of the coating head 20 as described in the above (1), and droplets are applied from all the nozzles with the basic ejection pattern described in (2) above. Repeatedly discharge. Then, the average discharge amount of droplets from each nozzle at this time is measured as described above using the discharge amount measuring device 30 described above. For example, 1000 large droplets A and B small droplets B are alternately ejected, and the total weight is divided by 1000 to obtain the average ejection amount.

  The above-mentioned average discharge amount measured by the discharge amount measuring device 30 is a theoretical average discharge amount of droplets to be theoretically discharged corresponding to the basic discharge pattern (theoretical average discharge for one droplet of the coating liquid of each nozzle). If there is a nozzle that is different from the (quantity), the combination over time of the types of droplets (large droplet A and small droplet B) that are continuously ejected from the nozzle is determined by the following (i) or (ii) As described above, the basic discharge pattern is changed to the changed discharge pattern. Thus, the average discharge amount of the droplets from the nozzle is adjusted to be the theoretical average discharge amount.

  (i) For nozzles whose average discharge amount measured by the discharge amount measuring device 30 is less than the theoretical average discharge amount, a changed discharge pattern with a higher discharge frequency of the type of droplets (large droplets A) with an increased discharge amount is used. A droplet is discharged. For example, as shown in FIG. 7B, the combination of the large droplet A and the small droplet B with the passage of time is [large droplet A, large droplet A, large droplet A, small droplet B]. It is assumed that the pattern in which the droplets are arranged in this order is repeated.

  (ii) For nozzles having an average discharge amount measured by the discharge amount measuring device 30 that is larger than the theoretical average discharge amount, a changed discharge pattern in which the discharge frequency of the type of droplets (small droplets B) with a reduced discharge amount is increased is used. A droplet is discharged. For example, as shown in FIG. 7C, the combination of the large droplet A and the small droplet B with the passage of time is [large droplet A, small droplet B, small droplet B, small droplet B]. It is assumed that the pattern in which the droplets are arranged in this order is repeated.

  In the above (i) and (ii), when the discharge frequency of the large droplet A is x and the discharge frequency of the small droplet B is y, x and y are average discharges measured by the discharge amount measuring device 30. Based on the quantity measurement results, it is calculated as follows.

  That is, in the coating apparatus 10, the discharge amount of the droplet (large droplet A) from the nozzle by the large voltage V1 is K1, and the discharge amount of the droplet (small droplet B) from the nozzle by the small voltage V2 is K2. In order to adjust the average discharge amount measured at the nozzle to the theoretical average discharge amount, when the corrected discharge amount to be set to the nozzle is M (K2 <M <K1), x = (M−K2 ) / (K1-K2), y = 1-x.

  For example, in the coating apparatus 10, the basic discharge pattern determined by the control device 40 is a repetition of [large droplet A / small droplet B] shown in FIG. 7A, and K1 = 110 ng / dot, K2 = 90 ng / dot. Then, the theoretical average discharge amount of each nozzle is 100 ng / dot. At this time, the result of measuring the average discharge amount of each nozzle of the coating head 20 by the discharge amount measuring device 30 is as shown in FIG. 8, for example, and the average discharge amount of the fifth nozzle is 95 ng / dot and adjusted. Is required, the average discharge amount from this nozzle must be corrected to 100 ng / dot, which is about 1.05 times that of 95 ng / dot. Therefore, the theoretical average discharge amount 100 ng / dot is multiplied by 1.05 to obtain the target average discharge amount M (= 100 × 1.05 = 105 ng / dot) of this nozzle. Thus, x = (105−90) ÷ (110−90) = 0.75 = 3/4 times, and y = 1−0.75 = 0.25 = 1/4 times. Accordingly, the combination of the large droplet A and the small droplet B with time is shown in FIG. 7 (B) as 4 [large droplet A, large droplet A, large droplet A, small droplet B]. The discharge pattern is changed to a droplet pattern.

According to the present embodiment, the following operational effects can be obtained.
(a) By controlling increase / decrease of the discharge amount for each nozzle of the coating head 20, the droplets discharged from each nozzle can be controlled into two types of large droplets A and small droplets B, and discharged continuously from each nozzle. A basic discharge pattern in which droplets to be combined are combined with a specific type over time is determined. Then, the average discharge amount of the droplets from each nozzle when the droplets are repeatedly discharged from each of the nozzles with the basic discharge pattern is measured, and the measured average discharge amount is theoretically corresponding to the basic discharge pattern. If there is a nozzle that is different from the theoretical average discharge amount that should be discharged to the nozzle, change the combination of the types of droplets that are continuously discharged from that nozzle over time from the basic discharge pattern to the changed discharge pattern. The average discharge amount of the droplets from is adjusted so as to be the theoretical average discharge amount.

  When the actual discharge amount per droplet of the coating liquid when discharged with the basic discharge pattern of each nozzle is different from the theoretical average discharge amount, the magnitude of the voltage itself applied to the piezoelectric element 23 facing the nozzle is determined. By simply changing the combination of the types of droplets ejected continuously from the nozzle over time without making fine adjustments, the average ejection amount of the droplets from the nozzle becomes the theoretical average ejection amount. Can be adjusted.

  Therefore, when a coating film is formed in a predetermined pattern on a substrate using such a coating apparatus 10, the droplets A to B, which are droplets continuously ejected from each nozzle, are used. The coating film unevenness due to the difference in the ejection amount of the droplets from the nozzles of the coating head 20 can be easily eliminated simply by changing the ejection pattern composed of the two types of droplets over time.

  (b) For nozzles where the measured average discharge amount of the droplets discharged from each nozzle is less than the theoretical average discharge amount, a change is made by increasing the discharge frequency of the type of droplets with a large discharge amount (large droplet A) By discharging the droplets with the discharge pattern, the average discharge amount of the droplets from the nozzle can be easily adjusted so as to become the theoretical average discharge amount.

  (c) For nozzles in which the measured average discharge amount of droplets discharged from each nozzle is larger than the theoretical average discharge amount, a change is made by increasing the discharge frequency of a type of droplets with a small discharge amount (small droplet B) By discharging the droplets with the discharge pattern, the average discharge amount of the droplets from the nozzle can be easily adjusted so as to become the theoretical average discharge amount.

  The coating apparatus 10 can easily adjust the unevenness of the coating film caused by the difference in the ejection amount of droplets from the nozzles of the coating head 20, so that the control operation by the control apparatus 40 can be performed as follows.

  (1 ′) As in the above (1), the control device 40 controls the increase and decrease of the discharge amount for each nozzle of the coating head 20 to control the number of droplets discharged from each nozzle, for example, large types. It is possible to control two types of droplets and small droplets.

  (2 ') The control device 40 determines a basic ejection pattern in which droplets continuously ejected from each nozzle of the coating head 20 are combined with a specific type over time, as in (2) above.

  In this basic ejection pattern, for example, FIG. 7A shows a combination of large droplets A and small droplets B over time, and two droplets of [large droplet A and small droplet B] are arranged in this order. The pattern can be repeated.

  (3 ′) The control device 40 controls the voltage applied to the piezoelectric element 23 facing each nozzle of the coating head 20 as described in (1) above, and the basic ejection pattern (2 ′) described above from each of all nozzles. The droplets ejected in step 1 are applied to the substrate 1. If there is unevenness in the coating film formed on the substrate 1 at this time, the types of droplets (large droplet A and small droplet B) continuously discharged from the nozzle corresponding to the unevenness are elapsed. The basic combination is changed from the basic discharge pattern to the changed discharge pattern as described in (i) or (ii) below, and adjusted so as to eliminate the unevenness of the coating film corresponding to the nozzle.

  (i) In the case where unevenness occurs due to the thin film thickness of the coating film formed on the substrate 1, for the nozzle corresponding to the uneven portion, the type of liquid droplet (large droplet A) having a large discharge amount is used. ) Droplets are ejected with a modified ejection pattern in which the ejection frequency is increased. For example, as shown in FIG. 7B, the combination of the large droplet A and the small droplet B with the passage of time is [large droplet A, large droplet A, large droplet A, small droplet B]. It is assumed that the pattern in which the droplets are arranged in this order is repeated.

  (ii) In the case where unevenness occurs due to the thick film of the coating film formed on the substrate 1, for the nozzle corresponding to the uneven portion, a droplet of a small discharge amount (small droplet B) ) Droplets are ejected with a modified ejection pattern in which the ejection frequency is increased. For example, as shown in FIG. 7C, the combination of the large droplet A and the small droplet B with the passage of time is [large droplet A, small droplet B, small droplet B, small droplet B]. It is assumed that the pattern in which the droplets are arranged in this order is repeated.

  The unevenness of the coating film can be determined by measuring the film thickness of the formed coating film using a film thickness measuring device, or by determining the color density of the surface of the formed coating film.

According to the present embodiment, the following operational effects can be obtained.
(a) By controlling increase / decrease of the discharge amount for each nozzle of the coating head 20, the droplets discharged from each nozzle can be controlled into two types of large droplets A to small droplets B, and discharged continuously from each nozzle. A basic discharge pattern in which droplets to be combined are combined with a specific type over time is determined. When the droplets ejected from each of the nozzles in the basic ejection pattern are applied to the substrate 1, if there is unevenness in the coating film formed on the substrate 1, the nozzles corresponding to the unevenness continuously. The time-dependent combination of the types of discharged liquid droplets is changed from the basic discharge pattern to the changed discharge pattern, and adjustment is performed so as to eliminate the unevenness of the coating film corresponding to the nozzle.

  (b) For the nozzle corresponding to the thin part of the coating film, by discharging the droplets with a modified discharge pattern in which the discharge frequency of the type of droplets with a large discharge amount (large droplet A) is increased, Adjustment can be easily made so as to eliminate unevenness of the coating film corresponding to the nozzle.

  (c) For the nozzle corresponding to the thick part of the coating film, the droplets are ejected with a modified ejection pattern in which the ejection frequency of the droplets with a small ejection amount (small droplets B) is increased, Adjustment can be easily made so as to eliminate unevenness of the coating film corresponding to the nozzle.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration of the present invention is not limited to this embodiment, and even if there is a design change or the like without departing from the gist of the present invention. It is included in the present invention. For example, in the control device 40 described above, the types of droplets ejected from each nozzle of the coating head 20 are two types of large droplets A and small droplets B. Three types of droplets may be used, and the droplet discharge pattern from each nozzle may be a combination of these three types of droplets over time. In this case, the voltage applied to the piezoelectric element 23 facing each nozzle is controlled to a large voltage, medium voltage, and small voltage, and a large droplet is ejected from the nozzle facing the piezoelectric element 23 to which the large voltage is applied. Medium droplets are ejected from the nozzle facing the piezoelectric element 23 to which the medium voltage is applied, and small droplets are ejected from the nozzle facing the piezoelectric element 23 to which the small voltage is applied.

  According to the present invention, it is possible to easily eliminate the unevenness of the coating film caused by the difference in the amount of droplets discharged from each nozzle of the coating head.

DESCRIPTION OF SYMBOLS 1 Substrate 10 Coating device 20 Coating head 30 Discharge amount measuring device 40 Control device

Claims (10)

While relatively moving the coating head and the substrate, in the coating method of applying the droplets ejected from a plurality of nozzles provided in the coating head to a substrate,
For each nozzle of the coating head, droplets are ejected with a basic ejection pattern consisting of a combination of droplets with different ejection amounts,
When the amount of droplets for a plurality of droplets continuously discharged from one nozzle is different from the required amount, the combination of droplets with different discharge amounts in the basic discharge pattern of this nozzle can be changed. A characteristic coating method. In the coating method of applying droplets discharged from a plurality of nozzles provided in the coating head along the relative movement direction while relatively moving the coating head and the substrate,
For each nozzle of the coating head, to eject droplets basic ejection pattern consisting of a combination of a plurality of types of droplets having different sizes, droplet of each of the nozzles when ejecting droplets by the basic discharge pattern The average discharge amount and the theoretical average discharge amount of the droplets to be discharged from the nozzle with the basic discharge pattern are compared, and if there is a nozzle having a different average discharge amount and the theoretical average discharge amount, A coating method, wherein a combination of droplets in the basic discharge pattern is changed so that the average discharge amount from the nozzle becomes the theoretical average discharge amount. For nozzles with an average discharge amount smaller than the theoretical average discharge amount, change the discharge frequency of a large discharge amount among a plurality of types of droplets constituting the basic discharge pattern,
The application according to claim 2, wherein, for a nozzle having a larger average discharge amount than the theoretical average discharge amount, the discharge frequency of a droplet having a small discharge amount among a plurality of types of droplets constituting the basic discharge pattern is changed. Method. In the coating method of applying droplets discharged from a plurality of nozzles provided in the coating head along the relative movement direction while relatively moving the coating head and the substrate,
For each nozzle of the coating head, droplets are ejected in a basic ejection pattern consisting of a combination of a plurality of types of droplets having different sizes, and droplets ejected from the nozzles in a basic ejection pattern and applied onto the substrate If there is unevenness in the coating film formed by the above , the combination of droplets in the basic discharge pattern of the droplets discharged from the nozzle corresponding to the uneven portion is changed so as to eliminate the unevenness of the coating film. Application method. If the unevenness is unevenness caused by the coating film is thin, the nozzles corresponding to the unevenness portion, a discharge frequency of large droplets of discharge amount among a plurality of types of droplets constituting the basic discharge pattern Change a lot,
If the unevenness is unevenness caused by the coating film is thick, the nozzles corresponding to the unevenness portion, a discharge frequency of small droplets of discharge amount among a plurality of types of droplets constituting the basic discharge pattern The coating method according to claim 4, wherein the coating method is changed a lot. A coating head having a plurality of nozzles; and a control device capable of controlling a discharge amount of droplets discharged from each nozzle of the coating head to a different discharge amount. In the coating apparatus for applying the droplets discharged from the plurality of nozzles to the substrate while moving,
The control device discharges droplets with a basic discharge pattern composed of a combination of droplets having different discharge amounts for each nozzle of the coating head, and drops a plurality of droplets continuously discharged from one nozzle. When the amount is different from the required amount , the coating apparatus is characterized in that the combination of droplets having different discharge amounts in the basic discharge pattern of the nozzle is changed . A coating head having a plurality of nozzles, a discharge amount measuring device for measuring a discharge amount of droplets from each nozzle of the coating head, and a control device for controlling a discharge amount of droplets from each nozzle of the coating head In the coating apparatus that applies the liquid droplets discharged from the plurality of nozzles along the relative movement direction to the substrate while relatively moving the coating head and the substrate.
The controller is
For each nozzle of the coating head, to eject droplets basic ejection pattern consisting of a combination of a plurality of types of droplets having different sizes, droplet of each of the nozzles when ejecting droplets by the basic discharge pattern The average discharge amount and the theoretical average discharge amount of the droplets to be discharged from the nozzle with the basic discharge pattern are compared, and if there is a nozzle having a different average discharge amount and the theoretical average discharge amount, coating apparatus wherein the average discharge rate from the nozzle to change the combination of the droplets in the basic discharge pattern so as to the theoretical average discharge amount.   For the nozzle having the average discharge amount smaller than the theoretical average discharge amount, the control device changes the discharge frequency of a large discharge amount among a plurality of types of droplets constituting the basic discharge pattern, and 8. The coating apparatus according to claim 7, wherein for a nozzle having an average discharge amount larger than the theoretical average discharge amount, a discharge frequency of a droplet having a small discharge amount among a plurality of types of droplets constituting the basic discharge pattern is changed. . A plurality of nozzles, and a control device that controls a discharge amount of droplets from each nozzle of the coating head, and the plurality of nozzles while relatively moving the coating head and the substrate. In a coating apparatus that applies the droplets discharged from the substrate along the relative movement direction with respect to the substrate,
The controller is
For each nozzle of the coating head, droplets are ejected in a basic ejection pattern consisting of a combination of a plurality of types of droplets having different sizes, and droplets ejected from the nozzles in a basic ejection pattern and applied onto the substrate If there is unevenness in the coating film formed by the above , the combination of droplets in the basic discharge pattern of the droplets discharged from the nozzle corresponding to the uneven portion is changed so as to eliminate the unevenness of the coating film. A coating device. In the case where the unevenness is unevenness caused by a thin coating film, the control device, for the nozzle corresponding to the unevenness portion , for a plurality of types of droplets constituting the basic discharge pattern, a droplet having a large discharge amount When the unevenness is uneven due to a thick coating film, the nozzle corresponding to the uneven portion has a discharge amount of a plurality of types of droplets constituting the basic discharge pattern. The coating apparatus according to claim 9, wherein the ejection frequency of small droplets is changed a lot.

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