JP2008264607A - Droplet coating device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a droplet coating device which can prevent defective coating due to variation of the coated amount of droplets. <P>SOLUTION: The droplet coating device 1 comprises a coating head 6 which discharges droplets from a plurality ejection holes arranged on a straight line toward a coating area of a relatively moving object K to be coated, and is made so as to gradually change the number of the ejection holes facing the coating area according to the relative movement between it and the object K to be coated, and a means which changes a droplet discharge timing interval according to the number of ejection holes facing the coating area on the relatively moving object K to be treated and discharging droplets at the same time, and changes the relative movement speed between the object K to be treated and the coating head 6 according to the change of the discharge timing interval. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a droplet coating apparatus and a droplet coating method for discharging and applying a plurality of droplets to an object to be coated.

  In the case of manufacturing a display device such as a liquid crystal display device, an organic EL (Electro Luminescence) display device, an electron emission display device, a plasma display device, or a semiconductor device, for example, when forming a color filter, It is used when a functional thin film such as an alignment film or a resist is formed on a substrate such as a glass substrate or a semiconductor wafer.

  This droplet coating apparatus includes a coating head (for example, an inkjet head) that discharges (sprays) droplets from a plurality of ejection holes (nozzles) toward a coating target such as a substrate. While relatively moving the application object, a plurality of droplets are sequentially landed on the application area of the application object by the application head to apply a predetermined application pattern.

  The coating head is formed so as to be tiltable by a predetermined tilt angle within a horizontal plane with respect to the relative movement direction. By changing the tilt position of the coating head determined by the tilt angle, the droplet coating pitch in the direction orthogonal to the relative movement direction can be adjusted. For example, in the manufacture of color filters, a technique has been proposed in which the coating head is tilted in accordance with the pixel pitch of each pixel to be colored, and the droplet coating pitch (landing interval) matches the pixel pitch (for example, Patent Documents). 1).

  When such a coating head and the coating object are relatively moved, the coating head is inclined by a predetermined inclination angle, so that the coating object is coated according to the relative movement between the coating head and the coating object. The number of discharge holes facing the region gradually increases, and becomes maximum when all the discharge holes face the application region, and then gradually decreases. At this time, since the coating head ejects droplets only from the ejection holes facing the coating region, the number of ejection holes for ejecting droplets changes according to the relative movement between the coating object and the coating head. Become.

Here, a piezoelectric coating head using a piezoelectric element increases or decreases the volume in the liquid chamber communicating with the ejection hole by driving the piezoelectric element (enlarges / restores the liquid chamber), and increases the volume by an operation to increase the volume (expansion operation). The solution is drawn into the chamber, the solution in the liquid chamber is pushed out by a volume reduction operation (restoration operation), and discharged as droplets from the discharge hole. Each liquid chamber communicates with a single main pipeline via a branch pipeline. In such a coating head, the amount of droplets ejected from each ejection hole decreases as the number of simultaneous ejection holes that simultaneously eject droplets increases. Usually, when all the discharge holes face the application area, that is, when droplets are discharged simultaneously from all the discharge holes, the droplet discharge amount is such that the required amount of droplets is applied to the application target. Is set.
JP-A-10-278314

  However, as described above, if the droplet discharge amount is set so that the required amount of droplets is applied to the application target when droplets are discharged simultaneously from all the discharge holes, all the discharges Until the hole faces the application area, more than the required amount of liquid droplets are applied to the application object, so that an area where the liquid droplet application amount is large is generated in the application area, that is, the liquid droplet application amount varies. Therefore, application defects such as coloring unevenness (thickness unevenness) occur.

  The present invention has been made in view of the above, and an object of the present invention is to provide a droplet coating apparatus and a droplet coating method capable of preventing a coating failure caused by variation in the amount of droplets applied. is there.

  A first feature according to an embodiment of the present invention is that in a droplet coating apparatus, a head that discharges droplets from a plurality of ejection holes arranged linearly toward a coating region on a relatively moving coating target. A coating head provided such that the number of ejection holes facing the coating area gradually changes according to relative movement with the coating object, and a coating area on the relatively moving coating object. Means for changing the droplet discharge timing interval according to the number of discharge holes for discharging droplets at the same time, and changing the relative movement speed between the coating object and the coating head according to the change of the discharge timing interval; It is.

  A second feature according to the embodiment of the present invention is that, in the droplet applying apparatus, a head that discharges droplets from a plurality of discharge holes arranged in a straight line toward a coating region on a relatively moving coating object. A coating head provided such that the number of ejection holes facing the coating area gradually changes according to relative movement with the coating object, and a coating area on the relatively moving coating object. And a means for changing the discharge amount of the liquid droplets discharged from the discharge holes in accordance with the number of the discharge holes discharging the liquid droplets at the same time.

  A third feature according to the embodiment of the present invention is that in the droplet coating method, a head that ejects droplets from a plurality of ejection holes arranged in a straight line toward a coating region on a relatively moving coating object. And a step of relatively moving the coating head and the coating target provided so that the number of ejection holes facing the coating region gradually change according to the relative movement with the coating target, and relative movement The droplet discharge timing interval is changed according to the number of discharge holes that are opposite to the application region on the application target and simultaneously discharge droplets, and the application target and the application head are relatively changed according to the change of the discharge timing interval. A step of applying droplets to the object to be applied by the application head while changing the moving speed.

  According to a fourth aspect of the present invention, in the droplet coating method, a head that ejects droplets from a plurality of ejection holes arranged in a straight line toward a coating region on a relatively moving coating object. And a step of relatively moving the coating head and the coating target provided so that the number of ejection holes facing the coating region gradually change according to the relative movement with the coating target, and relative movement Depending on the number of discharge holes that discharge the droplets at the same time, facing the application area on the application object, the droplets are applied to the application object by the application head while changing the discharge amount of the droplets discharged from the discharge holes. Applying.

  According to the present invention, it is possible to prevent application failure due to variations in the application amount of droplets.

  An embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, in the droplet applying apparatus 1 according to the embodiment of the present invention, the substrate K that is the object to be applied is in a horizontal state (in FIG. 1, a state along the X axis direction and the Y axis direction orthogonal thereto. ), The X-axis moving mechanism 3 that holds the moving table 2 and moves it in the X-axis direction, the detection unit 4 that detects the position of the moving table 2 in the X-axis direction, and the movement A driving driver 5 that drives the table 2, a coating head 6 that discharges droplets toward a rectangular coating region R (see FIG. 3) on the substrate K on the moving table 2, and the coating head 6 in the θ direction. A rotation mechanism 7 that rotates in the rotation direction along the horizontal plane in FIG. 1 and a control unit 8 that controls the X-axis movement mechanism 3, the drive driver 5, the coating head 6, and the rotation mechanism 7 are provided.

  The moving table 2 is stacked on the X-axis moving mechanism 3 and is provided so as to be movable in the X-axis direction. The moving table 2 is moved in the X-axis direction by the X-axis moving mechanism 3. The substrate K is placed on the movable table 2 by its own weight, but the present invention is not limited to this. For example, a mechanism such as an electrostatic chuck or an adsorption chuck is provided to hold the substrate K. Also good.

  The X-axis moving mechanism 3 is a mechanism that guides and moves the moving table 2 in the X-axis direction. The X-axis moving mechanism 3 is electrically connected to the drive driver 5. As the X-axis moving mechanism 3, for example, a linear motor moving mechanism using a linear motor as a driving source, a feed screw mechanism using a motor as a driving source, or the like is used.

  The detection unit 4 includes a linear scale 4a having a plurality of scales and a sensor head 4b that detects the scales. The linear scale 4a is attached to the X-axis moving mechanism 3 so that the scale is aligned in the X-axis direction. The sensor head 4 b is attached to the moving table 2 so that the scale of the linear scale 4 a can be detected, and is electrically connected to the drive driver 5. The detection unit 4 detects each scale of the linear scale 4a by the sensor head 4b, acquires the position of the moving table 2 in the X-axis direction, and transmits the position information (position signal) to the drive driver 5. As the detection unit 4, for example, an optical linear encoder, an electrostatic linear encoder, or the like is used.

  The drive driver 5 is a drive device that drives the X-axis movement mechanism 3 in accordance with a command (control signal) from the control unit 8. The drive driver 5 drives the X-axis movement mechanism 3 based on the position information of the movement table 2 transmitted from the detection unit 4, and moves the movement table 2 along the X-axis direction. The drive driver 5 is electrically connected to the control unit 8, and transmits position information (for example, a pulse signal) of the moving table 2 transmitted from the detection unit 4 to the control unit 8.

  The coating head 6 is an inkjet head that discharges liquid supplied from a solution tank (not shown) containing a solution such as ink as droplets from a plurality of discharge holes (nozzles) N (see FIG. 2). The coating head 6 is supported by the rotation mechanism 7 so as to be rotatable in the θ direction, and is electrically connected to the control unit 8. A solution such as ink is composed of a solute that remains as a residue on the substrate K and a solvent that dissolves (disperses) the solute. For example, ink that is a solution is composed of various components such as pigments, solvents (ink solvents), dispersants, and additives.

  As shown in FIG. 2, the coating head 6 has a nozzle body 6a having a plurality of ejection holes N for ejecting droplets, and a head body having a plurality of liquid chambers E communicating with the ejection holes N, respectively. 6b, a flexible plate 6c for changing the volumes of the liquid chambers E, and a plurality of piezoelectric elements 6d provided on the flexible plate 6c so as to correspond to the liquid chambers E, respectively.

  In the nozzle plate 6a, the discharge holes N are linearly arranged at a predetermined pitch (interval). For example, the number of discharge holes N is about several tens to several hundreds, the diameter of the discharge holes N is about several μm to several tens μm, and the pitch of the discharge holes N is several tens μm to several hundreds μm. Degree.

  The head main body 6b includes a main pipe M2 that communicates with each liquid chamber E that contains a solution via a branch pipe M1, and a liquid supply for supplying a solution from a solution tank to one end of the main pipe M2. A conduit M3 and a drain conduit M4 for communicating with the other end of the main conduit M2 and returning the solution to the solution tank are formed. The liquid supply line M3 is connected to the solution tank via a supply pipe P1 such as a tube or pipe. Similarly, the drain line M4 is connected to the solution tank via a discharge pipe P2 such as a tube or pipe. It is connected.

  The flexible plate 6c is a plate member for increasing or decreasing the volume of each liquid chamber E due to the deformation. The flexible plate 6c is attached to the head body 6b so as to be able to bend and deform, and functions as a wall portion of each liquid chamber E. Each piezoelectric element 6d is fixed to the flexible plate 6c so as to face each liquid chamber E. These piezoelectric elements 6 d are electrically connected to the control unit 8, and their driving is controlled by the control unit 8. By such driving of the piezoelectric element 6d, the flexible plate 6c is bent and deformed, and the volume of the liquid chamber E increases or decreases (the liquid chamber E expands / restores).

  Such a coating head 6 discharges the solution in each liquid chamber E as a droplet (ink droplet) from the corresponding discharge hole N according to the application of the drive voltage to each piezoelectric element 6d. Here, a solution is supplied from the solution tank into each liquid chamber E through the supply pipe P1, the liquid supply pipe M3, the main pipe M2, and the branch pipe M1, and each liquid chamber E is filled with the solution. When the piezoelectric element 6d is driven in this state, the solution is pushed out from the liquid chamber E corresponding to the driven piezoelectric element 6d, and is discharged from the discharge hole N as a droplet.

  More specifically, the piezoelectric element 6d contracts due to the application of a voltage to the piezoelectric element 6d, and the flexible plate 6c bends and deforms upward (in FIG. 2) accordingly (volume increasing operation, that is, expanding operation). The volume in the liquid chamber E increases, and the solution is drawn into the liquid chamber E from the main line M2 through the branch line M1. Thereafter, the piezoelectric element 6d is restored by releasing the voltage application, and the flexible plate 6c is restored accordingly (volume reduction operation, that is, restoration operation), whereby the volume in the liquid chamber E is also reduced and returned. . At this time, the solution in the liquid chamber E is pushed out and discharged as droplets from the discharge hole N. Excess solution is returned to the solution tank via the drainage pipe M4 and the discharge pipe P2.

  Returning to FIG. 1, the rotation mechanism 7 moves the coating head 6 in the θ direction (the rotation direction along the horizontal plane in FIG. 1), that is, the X-axis direction that is the relative movement direction in which the substrate K and the coating head 6 move relative to each other. The tilting mechanism tilts the coating head 6 so that the alignment direction in which all the discharge holes N are aligned is tilted in a horizontal plane. The rotating mechanism 7 is supported by a Y-axis moving mechanism (not shown) so as to be movable in the Y-axis direction, and is electrically connected to the control unit 8.

  For example, the inclination position of the coating head 6 is a position where the straight line L1 in the alignment direction of the ejection holes N is inclined with respect to the reference line L2 in the X-axis direction as shown in FIG. This tilt position is a position defined by the tilt angle θ1 from the reference line L2 in the X-axis direction. Note that by changing the inclination angle θ1, that is, the inclination position of the application head 6, the application pitch of droplets in the Y-axis direction perpendicular to the X-axis direction can be adjusted. Further, the application pitch in the X-axis direction can be adjusted by changing the droplet discharge frequency (discharge timing interval). Thus, the coating head 6 is positioned such that the number of ejection holes N facing the coating region R gradually changes according to a predetermined tilt position, that is, relative movement with the substrate K.

  Returning to FIG. 1 again, the control unit 8 includes a microcomputer that centrally controls each unit, and a storage unit that stores application information related to coating, various programs, and the like (none of which are shown). The application information includes information on a predetermined application pattern such as a dot pattern, an inclination position (inclination angle θ1) of the application head 6, an ejection frequency of the application head 6, and a moving speed (application speed) of the substrate K.

  The control unit 8 controls the X-axis movement mechanism 3 via the drive driver 5 based on the application information, and controls the application head 6 while moving the movement table 2 in the X-axis direction. A droplet is applied to the substrate K. At this time, the coating head 6 located at a predetermined tilt position sequentially discharges droplets toward the substrate K that moves relatively in the X-axis direction to sequentially form dot rows aligned in the Y-axis direction in the X-axis direction. The coating pattern is applied onto the coating region R (see FIG. 3) of the substrate K.

  Here, for example, pixels to be colored by the coating head 6 are arranged in a matrix of vertical and horizontal (XY axes) in the coating region R of the substrate K, and droplets (ink droplets) are applied to the pixels in the coating region R. Will be described in accordance with the relative movement of the substrate K by the coating head 6.

  As shown in FIG. 3, when the coating head 6 moves from the movement start position A1 to the coating start position A2 according to the relative movement of the substrate K in the X-axis direction, first, the left end (in FIG. 3) of the coating head 6 is detected. The discharge holes N face the pixels (that is, the application region R), and then the discharge holes N facing the pixels gradually increase, such as the second discharge hole N and the third discharge hole N from the left end. . Further, when the coating head 6 moves to the full discharge position A3 in accordance with the relative movement of the substrate K in the X-axis direction, the rightmost discharge hole N faces the pixel, and all the discharge holes N face the pixel, respectively. Become. In this way, in the coating head 6, the number of ejection holes N that eject droplets gradually increases.

  Thereafter, when the coating head 6 moves to the full discharge end position A4 in accordance with the relative movement of the substrate K in the X-axis direction, the discharge hole N at the left end of the coating head 6 does not first face the pixel, and then The discharge holes N facing the pixels gradually decrease, such as the second discharge hole N and the third discharge hole N from the left end. Further, when the coating head 6 moves to the coating completion position A5 in accordance with the relative movement of the substrate K in the X-axis direction, the rightmost discharge hole N no longer faces the pixel, and all the discharge holes N become pixels. They will not face each other. Thereafter, the coating head 6 moves to the stop position A6 according to the relative movement of the substrate K in the X-axis direction and stops. In this way, in the coating head 6, the number of ejection holes N that eject droplets is gradually reduced.

  Here, the relationship between the number of simultaneous ejection holes of the coating head 6 and the ejection amount of each ejection hole N is a curve B1 as shown in FIG. The number of simultaneous ejection holes is the number of ejection holes N when ejecting droplets simultaneously, and the ejection amount of each ejection hole N is the number of droplets ejected from each ejection hole N during simultaneous ejection of droplets. Discharge amount. It can be seen from the curve B1 shown in FIG. 4 that the discharge amount of each discharge hole N decreases as the number of simultaneous discharge holes increases. Therefore, in order to make the application amount of the droplet applied to the pixel constant, it is necessary to change the discharge amount of the droplet according to the number of the discharge holes N facing the application region R on the substrate K. One of the factors that cause the curve B1 shown in FIG. 4 is that when the droplets are simultaneously ejected from the plurality of ejection holes N, the solution is simultaneously drawn into the liquid chamber E from the main channel M2. Therefore, the flow of the solution in the main pipe M2 due to the drawing of the solution interferes with each other, which prevents the drawing of the solution into the liquid chamber E, and this action simultaneously increases the number of discharge holes N that are discharged simultaneously. It will be stronger.

  Next, the relationship between the discharge frequency of the coating head 6 and the discharge amount of each discharge hole N is a curve B2 as shown in FIG. The ejection frequency is an application timing interval at which a driving voltage is applied to a piezoelectric element that is arranged corresponding to each ejection hole N and ejects ink from the ejection hole N. It can be seen from the curve B2 shown in FIG. 5 that the discharge amount of each discharge hole N decreases as the discharge frequency increases. Therefore, in order to reduce the discharge amount of the droplets, it is necessary to increase the discharge frequency.

  Here, when the droplet ejection frequency is changed, the ejection timing interval at which ink is ejected changes accordingly. For example, when the discharge frequency is increased, the discharge timing interval is shortened accordingly. On the other hand, when the discharge frequency is lowered, the discharge timing interval is increased accordingly. For this reason, when the ejection frequency is changed, if the moving speed of the substrate K remains constant, the application pitch in the X-axis direction of the droplets in the pixel changes, so that the application is performed on the pixel. The application amount (total amount) of droplets changes.

  Therefore, the control unit 8 changes the moving speed of the substrate K according to the change of the discharge frequency (discharge timing interval), and maintains the droplet application pitch at a desired application pitch. Here, the relationship among the discharge frequency f, the moving speed v, and the coating pitch P is P = v / f. In order to keep P constant, when f is increased, v is increased correspondingly, and when f is decreased, v is decreased correspondingly.

  Accordingly, the ejection frequency is set to a waveform B3 as shown in FIG. 6 according to the position of the coating head 6 (coating head position). Based on the change in the ejection frequency of the waveform B3, the moving speed (coating speed) of the substrate K is set to a waveform B4 as shown in FIG. 7 according to the position of the coating head 6 (coating head position). . These waveform B3, B4, that is, the setting value of the ejection frequency corresponding to the position of the coating head 6 and the setting value of the moving speed of the substrate K are stored in the storage unit of the control unit 8 as coating information. The position of the coating head 6 indicates a relative position between the coating head 6 and the substrate K.

  Next, the application operation (application process) performed by the above-described droplet applying apparatus 1 will be described. Note that the control unit 8 of the droplet coating apparatus 1 executes a coating process to control driving of each unit. For example, the substrate K is a color filter substrate, and in the coating region R of the substrate K, pixels to be colored by the coating head 6 are arranged in a matrix of vertical and horizontal (XY axes).

  As shown in FIG. 8, the control unit 8 controls the rotation mechanism 7 based on the application information, and rotates the application head 6 in the θ direction to incline to an inclination position determined by a predetermined inclination angle θ1 (step S1). This inclination angle θ1 is an angle at which the application pitch (landing interval) of the droplets in the Y-axis direction becomes a desired application pitch (pixel pitch).

  Thereafter, the control unit 8 controls the X-axis moving mechanism 3 and the coating head 6 based on the coating information, and applies droplets to the coating region R of the substrate K that is relatively moved (step S2). That is, the coating head 6 discharges droplets toward the substrate K that moves relatively in the X-axis direction to sequentially form dot rows aligned in the Y-axis direction in the X-axis direction, and forms a predetermined coating pattern for a color filter. Formed on the substrate K.

  At this time, the control unit 8 performs relative processing based on the waveform B3 shown in FIG. 6 and the waveform B4 shown in FIG. 7, that is, based on the setting value of the ejection frequency according to the position of the coating head 6 and the setting value of the moving speed of the substrate K. The droplet ejection frequency (ejection timing interval) is changed according to the number of ejection holes N (simultaneous ejection holes) facing the coating region R of the moving substrate K and simultaneously ejecting droplets, and the ejection frequency is changed. Accordingly, the relative movement speed between the substrate K and the coating head 6 is changed. Here, since the coating head 6 is fixed, the moving speed (coating speed) of the substrate K is changed.

  That is, as shown in FIG. 6, the control unit 8 lowers the discharge frequency in accordance with the increase in the number of discharge holes N facing the coating region R of the relatively moving substrate K, and as shown in FIG. The moving speed of the substrate K is lowered according to the decrease in the frequency, and further, as shown in FIG. 6, the discharging frequency is increased according to the decrease in the number of the discharge holes N facing the coating region R of the relatively moving substrate K. As shown in FIG. 7, the relative movement speed is increased as the discharge frequency increases (see FIG. 4).

  Here, as shown in FIG. 6, the discharge frequency from the total discharge position A3 to the total discharge end position A4 is such that when a droplet is simultaneously discharged from all the discharge holes N of the coating head 6, a necessary amount of droplets The droplet discharge amount is set so as to be applied to the substrate K. The ejection frequency at the application start position A2 and the ejection frequency at the application completion position A5 are such that when a droplet is ejected from one ejection hole N of the coating head 6, a necessary amount of droplet is applied to the substrate K. The discharge amount of droplets is set in.

  As shown in FIG. 4, while the coating head 6 moves from the coating start position A2 to the total ejection position A3, the number of ejection holes N facing the coating region R on the substrate K gradually increases. As shown in FIG. 6, the discharge frequency is set to be gradually lowered, and further, as shown in FIG. 7, the moving speed (coating speed) of the substrate K is also set to be gradually lowered. As a result, the number of simultaneous ejection holes increases, but the ejection amount of the droplets ejected from each ejection hole N is constant, the required amount of droplets is applied to the substrate K, and further the X-axis direction of the droplets The coating pitch is maintained at a desired coating pitch without depending on a decrease in the discharge frequency.

  In addition, as shown in FIG. 4, while the coating head 6 moves from the full discharge end position A4 to the coating completion position A5, the number of discharge holes N facing the coating region R on the substrate K gradually decreases. Therefore, as shown in FIG. 6, the discharge frequency is set to be gradually increased, and further, as shown in FIG. 7, the moving speed (coating speed) of the substrate K is also set to be gradually increased. Has been. As a result, the number of simultaneous ejection holes decreases, but the ejection amount of the droplets ejected from each ejection hole N becomes constant, the required amount of droplets is applied to the substrate K, and the X axis of the droplets The coating pitch in the direction is maintained at a desired coating pitch without depending on the increase in the discharge frequency.

  In this way, the application amount of droplets (ink droplets) to each pixel is kept constant at the required amount, that is, the application amount (total amount) of droplets applied to each pixel becomes uniform, in addition, The coating pitch in the X-axis direction of the droplet is maintained at a desired coating pitch. As a result, it is possible to prevent uneven coloring due to variations in the coating amount of droplets, and as a result, the quality of the color filter substrate can be improved.

  As described above, according to the embodiment of the present invention, the number of discharge holes N that face the coating region R on the relatively moving substrate K and simultaneously discharge liquid droplets, that is, the number of simultaneous discharge holes is determined. The droplet ejection frequency (ejection timing interval) is changed, and the relative movement speed between the substrate K and the coating head 6 is changed in accordance with the change in the ejection frequency, thereby facing the coating region R in accordance with the relative movement of the substrate K. Even when the number of discharge holes N to be increased or decreased gradually, the discharge amount of the liquid droplets discharged from the discharge holes N is not dependent on the number of the discharge holes N. Further, it is possible to prevent the coating pitch of the droplets from changing in the X-axis direction due to the change in the ejection frequency. As a result, the required amount of droplets is uniformly applied to the application region R of the substrate K, and the application pitch in the X-axis direction of the droplets is maintained at a desired application pitch. It is possible to prevent poor coating due to the above.

  In particular, even when the coating head 6 and the type of ink having characteristics such as the curve B1 shown in FIG. 4 and the curve B2 shown in FIG. 5 are used, the ejection holes N facing the coating region R on the substrate K that moves relatively. The discharge frequency is lowered (that is, the discharge timing interval is lengthened) in accordance with the increase in the number of the substrate K, the moving speed of the substrate K is lowered according to the decrease in the discharge frequency (that is, the discharge timing interval is extended), and further the relative movement The discharge frequency is increased (that is, the discharge timing interval is shortened) in response to a decrease in the number of discharge holes N facing the coating region R on the substrate K to be increased, that is, the discharge frequency is increased (that is, the discharge timing interval is shortened). Accordingly, since the moving speed of the substrate K is increased, a necessary amount of droplets are uniformly applied to the coating region R of the substrate K, and furthermore, the coating pitch in the X-axis direction of the droplets is reliably set to a desired coating pitch. Since the lifting, it is possible to reliably prevent coating defects caused by variations in the droplet of the coating amount.

  In addition, since it is possible to apply a required amount of droplets by a simple control of switching the ejection frequency and the moving speed of the moving table 2, it is possible to suppress an increase in control data and a long processing time. .

(Other embodiments)
The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.

  For example, in the above-described embodiment, the discharge amount from each discharge hole N is adjusted by changing the discharge frequency. However, the present invention is not limited to this, and the magnitude of the voltage applied to the piezoelectric element 6d is adjusted. By changing, the discharge amount from each discharge hole N may be adjusted. That is, by increasing the voltage applied to the piezoelectric element 6d, the discharge amount from the discharge hole N increases, and therefore, between the number of discharge holes N that simultaneously discharge droplets and the discharge amount from the discharge hole N. In addition, when there is a characteristic such as a curve B1 shown in FIG. 4, the voltage applied to the piezoelectric element 6d is decreased as the number of ejection holes N through which droplets are ejected simultaneously decreases.

  Specifically, as shown in FIG. 3, while the coating head 6 moves from the coating start position A2 to the total ejection position A3, the number of ejection holes N facing the coating region R on the substrate K gradually increases. I will do it. Therefore, the voltage applied to the piezoelectric element 6d corresponding to the ejection hole N that ejects droplets is individually controlled, and the voltage applied to the piezoelectric element 6d is increased stepwise as the ejection hole N increases. On the other hand, as shown in FIG. 3, while the coating head 6 moves from the full discharge end position A4 to the coating completion position A5, the number of discharge holes N facing the coating region R on the substrate K gradually decreases. Go. Therefore, the voltage applied to the piezoelectric element 6d corresponding to the ejection hole N that ejects droplets is individually controlled, and the voltage applied to the piezoelectric element 6d is decreased stepwise as the ejection hole N decreases. As described above, the number of discharge holes N that face the coating region R on the relatively moving substrate K and simultaneously discharge droplets, that is, the discharge amount of the droplets discharged from the discharge holes N according to the number of simultaneous discharge holes. By changing the above, it is possible to obtain the same effect as that of the above-described embodiment.

  Further, in the above-described embodiment, the coating on the substrate K that moves relative to the case where the coating head 6 and the ink type having characteristics such as the curve B1 shown in FIG. 4 and the curve B2 shown in FIG. 5 are used is used. The droplet discharge frequency is changed according to the number of discharge holes N facing the region R, and the relative movement speed between the substrate K and the coating head 6 is changed according to the change of the discharge frequency, but this is not limited thereto. Even if the characteristics are different from those of the curve B1 shown in FIG. 4 and the curve B2 shown in FIG. 5, depending on the number of ejection holes N facing the coating region R on the substrate K that moves relative to the characteristics. Thus, the droplet discharge frequency can be changed, and the relative movement speed of the substrate K and the coating head 6 can be changed according to the change of the discharge frequency. For example, when the curve B2 shown in FIG. 5 is different and the discharge amount of each discharge hole N increases as the discharge frequency increases, the waveform B3 shown in FIG. 6 and the waveform B4 shown in FIG. That is, the setting value of the ejection frequency and the setting value of the moving speed of the substrate K corresponding to the position of the coating head 6 are changed.

  Furthermore, in the above-described embodiment, the substrate K is moved with respect to the coating head 6. However, the present invention is not limited to this, and the coating head 6 may be moved with respect to the substrate K. The substrate K and the coating head 6 may be moved relative to each other.

  Finally, in the above-described embodiment, the coating head 6 is provided so as to be rotatable in the θ direction (rotation direction along the horizontal direction) by the rotation mechanism 7. However, the present invention is not limited to this. It may be fixed at an angle. That is, in the coating head 6, the relative number of the coating head 6 and the substrate K causes the number of ejection holes N facing the coating region R on the substrate K, that is, the number of ejection holes N that simultaneously eject droplets, gradually. It may be arranged so as to change to (increase or decrease gradually).

1 is a perspective view showing a schematic configuration of a droplet applying apparatus according to an embodiment of the present invention. It is sectional drawing which shows schematic structure of the coating head with which the droplet coating apparatus shown in FIG. 1 is provided. It is explanatory drawing for demonstrating the relative positional relationship of the application head and a board | substrate in the application | coating operation | movement which the droplet application apparatus shown in FIG. 1 performs. It is explanatory drawing for demonstrating the relationship between the number of simultaneous discharge holes, and the discharge amount of each discharge hole. It is explanatory drawing for demonstrating the relationship between a discharge frequency and the discharge amount of each discharge hole. It is explanatory drawing for demonstrating the relationship between a coating head position and discharge frequency. It is explanatory drawing for demonstrating the relationship between a coating head position and a coating speed. It is a flowchart which shows the flow of the application | coating operation | movement which the droplet application apparatus shown in FIG. 1 performs.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Droplet coating device 6 Coating head K Application object (board | substrate)
R Application area N Discharge hole

Claims (6)

A head for discharging droplets from a plurality of discharge holes arranged in a straight line toward a coating area on a coating object to be moved relative to the coating area, and facing the coating area according to relative movement with the coating object. An application head provided so that the number of the ejection holes to be changed gradually;
The droplet discharge timing interval is changed in accordance with the number of the discharge holes that discharge the droplets at the same time, facing the application region on the coating object to be relatively moved, and the application in accordance with the change in the discharge timing interval Means for changing the relative movement speed between the object and the coating head;
A droplet applying apparatus comprising:   The changing means extends the discharge timing interval by extending the discharge timing interval in response to an increase in the number of the discharge holes that discharge the liquid droplets at the same time facing the application region on the application object to be relatively moved. In response to the decrease in the relative movement speed, the discharge timing interval is shortened in accordance with the decrease in the number of the discharge holes that simultaneously discharge the liquid droplets facing the application region on the relatively moving application object, and the discharge The droplet coating apparatus according to claim 1, wherein the relative movement speed is increased according to a shortening of the timing interval. A head for discharging droplets from a plurality of discharge holes arranged in a straight line toward a coating area on a coating object to be moved relative to the coating area, and facing the coating area according to relative movement with the coating object. An application head provided so that the number of the ejection holes to be changed gradually;
Means for changing the discharge amount of the liquid droplets discharged from the discharge holes in accordance with the number of the discharge holes that simultaneously discharge the liquid droplets while facing the application region on the application object to be relatively moved;
A droplet applying apparatus comprising: A head for discharging droplets from a plurality of discharge holes arranged in a straight line toward a coating area on a coating object to be moved relative to the coating area, and facing the coating area according to relative movement with the coating object. The relative movement of the coating head and the coating object provided so that the number of the discharge holes to gradually change,
The droplet discharge timing interval is changed in accordance with the number of the discharge holes that discharge the droplets at the same time, facing the application region on the coating object to be relatively moved, and the application in accordance with the change in the discharge timing interval Applying the droplets to the application object by the application head while changing the relative movement speed between the object and the application head;
A droplet coating method comprising:   The applying step extends the discharge timing interval by extending the discharge timing interval in response to an increase in the number of the discharge holes that discharge the liquid droplets at the same time facing the application area on the application object to be relatively moved. In response to the decrease in the relative movement speed, the discharge timing interval is shortened in accordance with the decrease in the number of the discharge holes that simultaneously discharge the liquid droplets facing the application region on the relatively moving application object, and the discharge 5. The droplet coating method according to claim 4, wherein the relative movement speed is increased in accordance with the shortening of the timing interval. A head for discharging droplets from a plurality of discharge holes arranged in a straight line toward a coating area on a coating object to be moved relative to the coating area, and facing the coating area according to relative movement with the coating object. The relative movement of the coating head and the coating object provided so that the number of the discharge holes to gradually change,
The coating head while changing the ejection amount of the droplets ejected from the ejection holes in accordance with the number of ejection holes that simultaneously eject the droplets facing the coating area on the coating object to be relatively moved Applying the droplets to the application object by:
A droplet coating method comprising:

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