JP2009195868A - Inspection method for discharge head, discharge head inspection apparatus and portraying method - Google Patents

Abstract

Disclosed is a discharge amount inspection method that is not affected by the discharge order of each nozzle group.
The present invention relates to a method for inspecting a droplet discharge head that drives a plurality of discharge element groups to discharge a liquid material from a first nozzle group 111a to a third nozzle group 111c. A first discharge step of continuously driving a plurality of discharge element groups to discharge the functional liquid, a first measurement step of measuring the discharge amount of the functional liquid discharged in the first discharge step, and an average for each discharge element group A calculation step of calculating the discharge amount 110 and calculating the appropriate condition of the drive signal corresponding to each of the discharge element groups based on the average discharge amount 110, and continuously driving the plurality of discharge element groups by the drive voltage 114 of the appropriate condition The second discharge step for discharging the functional liquid, the second measurement step for measuring the discharge amount of the functional liquid discharged in the second discharge step, and the maximum value and the minimum value of the discharge amount for each discharge element group were calculated. And determining a quality of the ejection head based on the maximum value and the minimum value.
[Selection] Figure 9

Description

  The present invention relates to a discharge head inspection method, a discharge head inspection apparatus, and a drawing method, and more particularly to a method for inspecting whether or not a discharge amount can be discharged with high accuracy.

  2. Description of the Related Art Conventionally, as a method for ejecting droplets onto a workpiece, a method for ejecting droplets using an ink jet droplet ejecting apparatus is known. The droplet discharge device includes a table on which a workpiece such as a substrate is placed, and a carriage on which an inkjet head (hereinafter referred to as a droplet discharge head) is arranged. Then, the table and the carriage are moved relative to each other, and droplets are ejected from the droplet ejection head onto the work and applied.

  This droplet discharge head includes a plurality of nozzles. When discharging from a plurality of nozzles at the same time according to the drawing pattern, the drive characteristics fluctuate, and the discharge characteristics change. A method for stabilizing the discharge characteristics is introduced in Patent Document 1. According to this, the number of nozzles ejected simultaneously is reduced by dividing the nozzles into a plurality of nozzle groups and sequentially driving the nozzle groups. And the fluctuation | variation of the load driven simultaneously is reduced.

  In addition, since the droplet discharge head has a different flow path for each nozzle, the discharge characteristics may be different for each nozzle. Japanese Patent Application Laid-Open No. 2004-228561 introduces a method for bringing the discharge characteristics of each nozzle closer. According to this, the droplet discharge head includes a piezoelectric vibrator (hereinafter referred to as a piezoelectric element), and discharges droplets by expanding and contracting the piezoelectric element. A plurality of drive signals for driving the piezoelectric element are supplied, and the switch circuit selects an appropriate drive signal from the plurality of drive signals and supplies it to the piezoelectric element. Then, the piezoelectric element is driven using an appropriate drive signal for each nozzle.

JP 2001-246738 A JP 2000-52570 A

  When a piezoelectric element is driven for each nozzle group, a difference may occur in the discharge amount for each nozzle group due to the influence of the discharge order for each nozzle group and the difference in characteristics in the circuit elements constituting the drive circuit. When the discharge amount of each nozzle is inspected, the discharge amount including the difference in discharge amount for each nozzle group is inspected. There has been a demand for a discharge amount inspection method that does not include a difference in discharge amount for each nozzle group.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1]
An ejection head inspection method according to this application example is an ejection head inspection method for driving a plurality of ejection element groups to eject a liquid material from nozzles of the ejection elements, and driving the plurality of ejection element groups. A first discharge step for discharging the liquid material, a first measurement step for measuring the discharge amount of the liquid material discharged in the first discharge step, and the first measurement step for each discharge element group. A calculation step of calculating a statistical value of the measured discharge amount, and calculating an appropriate condition of the drive signal corresponding to the discharge element group based on the statistical value, and a plurality of the discharges by the drive signal of the appropriate condition A second discharge step of driving the element group to discharge the liquid material, a second measurement step of measuring the discharge amount of the liquid material discharged in the second discharge step, and the discharge element group for each of the discharge element groups Based on the discharge amount measured in the second measurement process A determination step of determining acceptability of the serial ejection head, characterized by having a.

  According to this ejection head inspection method, after the ejection amount is measured for each ejection element group, the statistical value of the ejection amount for each ejection element group is calculated. And after calculating the appropriate condition of a drive signal using the statistical value, it discharges with the drive signal of an appropriate condition. Next, pass / fail is determined based on the discharge amount in the drive signal under the appropriate conditions. Therefore, since the quality of the plurality of ejection element groups is determined based on the ejection amount under the appropriate conditions, the quality determination can be performed with high accuracy.

[Application Example 2]
In the ejection head inspection method according to the application example, the statistical value calculated in the calculation step is an average value, and the appropriate condition is that the average value of the ejection amount for each ejection element group is substantially the same. It is calculated by the following.

  According to this ejection head inspection method, whether or not the average value of the ejection amount for each ejection element group is substantially the same is determined. Therefore, it is possible to determine whether or not the ejection head is good while the difference in ejection amount between the ejection element groups is small.

[Application Example 3]
In the ejection head inspection method according to the application example, the appropriate condition of the drive signal is calculated by adding or subtracting an offset value to the drive signal so that dispersion of the ejection amount in each ejection element is reduced. It is characterized by that.

  According to this ejection head inspection method, the quality is judged in a state where the dispersion of the ejection amount in each ejection element is small. Therefore, it is possible to determine whether or not the ejection head is good when driving with a drive signal under an appropriate condition for reducing the dispersion between the ejection element groups.

[Application Example 4]
An ejection head inspection apparatus according to this application example is an ejection head inspection apparatus that drives a plurality of ejection element groups to eject a liquid material from nozzles of the ejection elements, and forms a drive signal that drives the ejection elements. A driving signal forming unit; a measuring unit for measuring a discharge amount of the liquid material discharged from the nozzle; and a discharge value statistical value for each discharge element group, and the discharge element group based on the statistical value And an appropriate condition calculation unit that calculates an appropriate condition of the drive signal corresponding to each of the above and a pass / fail determination unit that determines pass / fail of the discharge head based on the discharge amount of the discharge head.

  According to this discharge head inspection apparatus, the liquid element is discharged from the nozzle by driving the discharge element using the drive signal formed by the drive signal forming unit. Then, the discharge amount of the liquid material discharged by the measurement unit is measured. Next, an appropriate condition calculation unit calculates a statistical value of the ejection amount for each ejection element group, and computes an appropriate condition for the drive signal corresponding to each ejection element group. Then, the ejection element is driven using the drive signal formed by the drive signal forming unit under appropriate conditions, and the liquid material is ejected from the nozzle. Next, the measurement unit measures the discharge amount of the liquid material to be discharged, and the pass / fail determination unit determines pass / fail of the discharge head based on the discharge amount. Therefore, since the quality of the plurality of ejection element groups is determined based on the ejection amount under the appropriate conditions, the quality determination can be performed with high accuracy.

[Application Example 5]
In the ejection head inspection apparatus according to the application example, the statistical value calculated by the appropriate condition calculation unit is an average value, and the appropriate condition is such that the average value of the discharge amount for each of the discharge element groups is substantially the same. It is calculated by the following.

  According to this ejection head inspection device, the quality is judged in a state where the average value of the ejection amount for each ejection element group is substantially the same. Therefore, it is possible to determine whether or not the ejection head is good while the difference in the average ejection amount between the ejection element groups is small.

[Application Example 6]
In the ejection head inspection apparatus according to the application example, the appropriate condition of the drive signal is calculated by adding or subtracting an offset value to the drive signal so that dispersion of the ejection amount in each ejection element group is reduced. It is characterized by that.

  According to this ejection head inspection apparatus, the quality is judged in a state where the dispersion of the ejection amount in each ejection element group is small. Therefore, it is possible to determine whether the ejection head is good or bad while taking measures for driving with a drive signal under an appropriate condition that reduces the dispersion between the ejection element groups.

[Application Example 7]
The drawing method according to this application example is a drawing method of driving a plurality of discharge element groups to discharge a liquid material from a nozzle of the discharge elements onto a work, and driving the plurality of discharge element groups to form the liquid material A discharge amount measurement step of measuring the discharge amount, and calculating a statistical value of the discharge amount measured in the discharge amount measurement step for each discharge element group, and the discharge element group based on the statistical value And a drawing step of drawing the liquid material on the workpiece for drawing.

  According to this drawing method, after the discharge amount is measured for each discharge element group, the statistical value of the discharge amount for each discharge element group is calculated. And after calculating the appropriate condition of a drive signal using the statistical value, it discharges with the drive signal of an appropriate condition. Next, drawing is performed based on the ejection amount in the drive signal under the appropriate conditions. Accordingly, since the plurality of ejection element groups are drawn based on the ejection amount under the appropriate conditions, it is possible to perform ejection and drawing with a precise ejection amount.

Hereinafter, specific embodiments will be described with reference to the drawings.
In addition, each member in each drawing is illustrated with a different scale for each member in order to make the size recognizable on each drawing.

(First embodiment)
In the present embodiment, a characteristic droplet discharge head inspection apparatus of the present invention and an example of inspecting the discharge amount of a droplet discharge head using this droplet discharge head inspection apparatus will be described with reference to FIGS. To do.

(Droplet ejection head)
First, the droplet discharge head will be described. FIG. 1A is a schematic perspective view showing the configuration of the droplet discharge head. As shown in FIG. 1A, the droplet discharge head 1 includes a nozzle plate 3 on which nozzles 2 are formed. A first case 4 is formed below the nozzle plate 3, and a second case 5 is formed below the first case 4. And the attachment hole 5a is formed in the upper surface of the 2nd case 5, and the internal thread is formed in the attachment hole 5a.

  A circuit board 6 is disposed in the middle of the second case 5, and is formed to extend from the side surface of the second case 5 in the direction opposite to the X direction. One connector 7 and a switching circuit element 8 as a switching unit are disposed on the lower surface of the circuit board 6. A pair of supply ports 9 project from the lower side of the second case 5, and the functional liquid is supplied to the droplet discharge head 1 through the supply ports 9.

  FIG. 1B shows the nozzle plate. As shown in FIG. 1B, the nozzle plate 3 is formed with 15 nozzles 2 arranged in the X direction. The nozzles 2 continue from the left side to the right side in the drawing from the first nozzle 2a to the fifteenth nozzle 2q.

  FIG. 1C is a schematic cross-sectional view of a main part for explaining the structure of the droplet discharge head. As shown in FIG. 1C, the droplet discharge head 1 includes a nozzle plate 3, and the nozzle 2 is formed on the nozzle plate 3. A cavity 10 as a pressure chamber communicating with the nozzle 2 is formed on the upper side of the nozzle plate 3 and facing the nozzle 2. Then, the functional liquid 11 as a liquid material is supplied to the cavity 10 of the droplet discharge head 1 through the supply port 9 and a flow path (not shown).

  On the upper side of the cavity 10, a vibration plate 12 that vibrates in the vertical direction (Z direction) and expands and contracts the volume in the cavity 10 and a piezoelectric element 13 that expands and contracts in the vertical direction and vibrates the vibration plate 12 are disposed. Has been. The piezoelectric element 13 expands and contracts in the vertical direction to pressurize and vibrate the diaphragm 12, and the diaphragm 12 pressurizes the cavity 10 by enlarging and reducing the volume in the cavity 10. Thereby, the pressure in the cavity 10 fluctuates, and the functional liquid 11 supplied into the cavity 10 is discharged through the nozzle 2.

  When the droplet discharge head 1 receives a drive signal for controlling and driving the piezoelectric element 13, the piezoelectric element 13 expands and the diaphragm 12 reduces the volume in the cavity 10. As a result, the functional liquid 11 corresponding to the reduced volume is ejected as droplets 14 from the nozzle 2 of the droplet ejection head 1. In this droplet discharge head 1, a droplet discharge element 15 is configured by the nozzle 2, the cavity 10, the vibration plate 12, the piezoelectric element 13, and the like, and a plurality of droplet discharge elements 15 are arranged and formed.

(Discharge head inspection device)
Next, the ejection head inspection device 18 that measures the ejection amount after ejecting droplets onto the substrate will be described with reference to FIGS. There are various types of methods for discharging droplets, but it is preferable to use an inkjet method. The ink jet method is suitable for microfabrication because it can discharge minute droplets.

  FIG. 2 is a schematic perspective view showing the configuration of the ejection head inspection apparatus. The functional liquid 11 is ejected as droplets 14 by the ejection head inspection device 18 and then applied. Then, the volume of the applied droplet is measured, and a quality check is performed. As shown in FIG. 2, the discharge head inspection device 18 includes a base 19 formed in a rectangular parallelepiped shape. In the present embodiment, the longitudinal direction of the base 19 is the X direction, and the direction orthogonal to the X direction is the Y direction.

  An X fixed table 20 is disposed on the upper surface 19 a of the base 19, and a pair of guide rails 21 extending in the X direction protrudes over the entire X direction width of the X fixed table 20 on the upper surface 20 a of the X fixed table 20. It is installed. An X table 22 having a linear motion mechanism (not shown) corresponding to the pair of guide rails 21 is attached to the upper side of the guide rails 21. The X table 22 linear movement mechanism is, for example, a screw type linear movement mechanism including a screw shaft (drive shaft) extending in the X direction along the guide rail 21 and a ball nut screwed to the screw shaft. The drive shaft is connected to an X-axis motor 23 that receives a predetermined pulse signal and rotates forward and backward in steps. When a drive signal corresponding to a predetermined number of steps is input to the X-axis motor 23, the X-axis motor 23 rotates forward or reverse, and the X table 22 moves in the X direction by an amount corresponding to the same number of steps. It is like that. Further, an X table position detecting device (not shown) is arranged on the upper surface 20 a of the X fixed table 20 in parallel with the guide rail 21 so that the position of the X table 22 can be measured.

  A pair of guide rails 24 extending in the Y direction is provided on the upper surface 22 a of the X table 22 so as to protrude over the entire width of the X table 22 in the Y direction. On the upper side of the guide rail 24, a Y table 25 having a linear motion mechanism (not shown) corresponding to the pair of guide rails 24 is attached. The linear motion mechanism of the Y table 25 is, for example, the same mechanism as the linear motion mechanism included in the X table 22 in this embodiment. And the Y-axis motor 26 is connected with the drive shaft with which the linear motion mechanism is provided. When a drive signal corresponding to a predetermined number of steps is input to the Y-axis motor 26, the Y-axis motor 26 rotates forward or backward so that the Y table 25 moves in the Y direction by an amount corresponding to the same number of steps. It has become.

  A placement surface 27 is formed on the upper surface of the Y table 25, and a suction-type substrate chuck mechanism (not shown) is provided on the placement surface 27. When the substrate 28 is placed on the placement surface 27, the substrate 28 is positioned and fixed at a predetermined position on the placement surface 27 by the substrate chuck mechanism.

  On the upper surface 19 a of the base 19, an L-shaped support base 29 is erected on the side opposite to the X direction. On the upper surface 29 a of the support base 29, the droplet discharge head 1 and the supply tank 30 are provided. Has been placed. The droplet discharge head 1 and the supply tank 30 are connected by a tube (not shown) so that the functional liquid 11 stored in the supply tank 30 is supplied to the droplet discharge head 1 through the tube. It has become.

  On the upper surface 19a of the base 19, a substantially rectangular Z fixing table 31 is erected in the X direction. In the Z fixing table 31, a pair of guide rails (not shown) are provided on the side surface 31a opposite to the X direction. Arranged in the Z direction. In the guide rail, a Z table 32 having a linear motion mechanism (not shown) corresponding to the pair of guide rails is disposed on the opposite side in the X direction. The linear motion mechanism of the Z table 32 is, for example, the same mechanism as the linear motion mechanism included in the X table 22 in this embodiment. And the Z-axis motor 33 is connected with the drive shaft with which the linear motion mechanism is provided. When a drive signal corresponding to a predetermined number of steps is input to the Z-axis motor 33, the Z-axis motor 33 rotates forward or reverse, and the Z table 32 moves in the Z direction by an amount corresponding to the same number of steps. It has become.

  And in the Z table 32, the support part 34 is protrudingly formed and formed in the side surface 32a on the opposite side to a X direction. An imaging device 35 is arranged on the opposite side of the support portion 34 in the X direction, and an imaging lens 36 is arranged on the lower side of the imaging device 35. An illuminating device 37 and an optical device 38 that guides the laser light emitted from the illuminating device 37 to the imaging lens 36 are arranged below the support portion 34, and a part of the laser light can irradiate the substrate 28. The imaging device 35 includes an area sensor made up of a solid-state imaging device or the like. Then, after the imaging lens 36 projects an image of the surface of the substrate 28 onto the area sensor, the area sensor can convert the projected image into an electrical signal and output it. A control device 39 is disposed in the Y direction of the base 19, and this control device 39 controls the ejection head inspection device 18.

  FIG. 3 is an electric control block diagram of the droplet discharge position measuring apparatus. In FIG. 3, the control device 39 includes a CPU (arithmetic processing device) 42 that performs various types of arithmetic processing as a processor, and a memory 43 that stores various types of information.

  X table drive device 44, X table position detection device 45, Y table drive device 46, Y table position detection device 47, Z table drive device 48, Z table position detection device 49, head drive circuit 50, functional liquid supply drive device 51 Are connected to the CPU 42 via the input / output interface 52 and the data bus 53. Further, the input device 54, the display device 55, the imaging device 35, and the illumination device 37 are also connected to the CPU 42 via the input / output interface 52 and the data bus 53.

  The X table drive device 44 is a device that controls the movement of the X table 22 by driving the X axis motor 23, and the X table position detection device 45 is a device that detects the position of the X table 22 in the X direction. . Similarly, the Y table driving device 46 is a device that controls the movement of the Y table 25 disposed on the upper side of the X table 22 by driving the Y axis motor 26, and the Y table position detecting device 47 is a Y table. 25 is a device for detecting the position in the Y direction. After the X table position detecting device 45 and the Y table position detecting device 47 detect the positions of the X table 22 in the X direction and the Y table 25 in the Y direction, the X table driving device 44 and the Y table driving device 46 are moved to the X table. By moving 22 and the Y table 25, it is possible to move the substrate 28 mounted on the mounting surface 27 to a desired position and stop it.

  The Z table drive device 48 is a device that controls the movement of the Z table 32 by driving the Z axis motor 33, and the Z table position detection device 49 is a device that detects the position of the Z table 32 in the Z direction. . After the Z table position detection device 49 detects the position of the Z table 32 in the Z direction, the Z table drive device 48 moves the Z table 32 to move the Z table 32 to a desired position and stop it. Is possible. Since the Z table 32 is disposed in the imaging device 35 via the support portion 34, the imaging device 35 can be moved to a place where the distance between the imaging device 35 and the substrate 28 becomes a desired distance and stopped. It is possible.

  The head drive circuit 50 is a circuit that drives the droplet discharge head 1. Then, the head drive circuit 50 drives the droplet discharge head 1 in accordance with discharge conditions such as the drive voltage, the number of discharges, and the discharge interval indicated by the CPU 42. The functional liquid supply driving device 51 is a device that drives a supply device built in the supply tank 30 to supply the functional liquid 11 to the droplet discharge head 1. Then, the functional liquid 11 is sucked from a tank (not shown) and supplied to the supply tank 30. And it has the function to keep the water level of the functional liquid 11 in the supply tank 30 at a predetermined water level.

  The input device 54 is an apparatus that inputs various discharge conditions for discharging the droplets 14 and various conditions for measuring the positions of the discharged droplets 14. For example, the input device 54 measures the droplets 14 discharged to the substrate 28. A device for inputting a procedure. The display device 55 is a device that displays discharge conditions and work statuses, and an operator performs an input operation using the input device 54 based on information displayed on the display device 55.

  The imaging device 35 has a built-in conversion circuit that converts a captured image into a digital signal, and can transmit image information as a digital signal. When an instruction signal for capturing an image is received from the CPU 42, after the image is captured, a digital signal of the image is transmitted to the CPU 42. Furthermore, the imaging device 35 has a function of switching the imaging magnification, and can switch the magnification of the image to be captured according to an instruction from the CPU 42.

  The illuminating device 37 is a device that irradiates laser light, and can switch the intensity of the irradiating light in accordance with an instruction signal output from the CPU 42. A means for detecting the intensity of irradiated light and a function for transmitting the detected light intensity to the CPU 42 are provided.

  The memory 43 is a concept including a semiconductor memory such as a RAM and a ROM, and an external storage device such as a hard disk and a CD-ROM. Functionally, a storage area for storing the program software 57 in which the operation control procedure in the ejection head inspection apparatus 18 is described is set. Furthermore, a storage area for storing drive signal data 58 that is a condition for driving the droplet discharge head 1 is also set. In addition, storage areas such as data for measuring the discharge amount of the discharged droplet 14 and discharge amount measurement data 59 that is data related to the measurement are set. Furthermore, a storage area for storing appropriate condition data 60 for calculating an appropriate drive signal from the discharge amount measurement data 59 is also set. In addition, there are storage areas such as pass / fail judgment data 61, which is data such as judgment values when judging pass / fail after inspection, a storage area that functions as a work area for the CPU 42, a temporary file, and other various storage areas. Is set.

  The CPU 42 performs control for ejecting the functional liquid 11 as droplets 14 onto the substrate 28 and control for measuring the ejection amount of the droplets 14 in accordance with the program software 57 stored in the memory 43. As a specific function realization unit, there is a discharge calculation unit 62 that performs a calculation for discharging the droplet 14 by the droplet discharge head 1. If the discharge calculation unit 62 is divided in detail, a drive signal forming unit 63 is provided that inputs a condition for driving the droplet discharge head 1 from the memory 43 and calculates a drive signal. In addition, various function calculation units such as a discharge control calculation unit 64 that controls the start and stop of discharge from the droplet discharge head 1 are provided.

  In addition, there is a table control calculation unit 65 that performs control to move the substrate 28 from a location facing the droplet discharge head 1 to a location facing the imaging device 35. Furthermore, it has the discharge amount measurement calculating part 66 which calculates the volume of the droplet 14 from the image data which the imaging device 35 images. In addition, an appropriate condition calculation unit 67 that calculates an appropriate drive signal using the discharge amount measurement data 59, and a pass / fail determination unit that compares the discharge amount with the pass / fail determination data 61 to determine pass / fail of the droplet discharge head 1. 68.

  FIG. 4 is an electric control block diagram of the head driving circuit and the droplet discharge head. In FIG. 4, the flow of the drive signal for driving the piezoelectric element 13 will be described. The drive signal forming unit 63 in the control device 39 forms the drive signal data 58 and stores it as the drive signal data 58 in the memory 43. The control device 39 transmits the drive signal data 58 to the head drive circuit 50. The head drive circuit 50 includes a waveform dividing unit 70, a DA (Digital Analog) converter 71, and a synchronization circuit 72. The waveform dividing unit 70 includes a memory that stores drive signal data 58 transmitted from the control device 39. The drive signal data 58 includes drive waveform data and drive timing data. The DA converter 71 includes five DA converters 71, a first DA converter 71a to a fifth DA converter 71e. Then, the waveform dividing unit 70 divides the drive waveform data into waveforms for driving every third piezoelectric element 13, outputs the waveform to the DA converter 71, and outputs the drive timing data to the synchronization circuit 72. The synchronization circuit 72 inputs drive timing data and outputs it to the DA converter 71 and the switching circuit element 8 of the droplet discharge head 1. The DA converter 71 DA-converts the input drive waveform data to form a drive waveform, and outputs the drive waveform to the switching circuit element 8 of the droplet discharge head 1 in synchronization with the input drive timing data.

  The droplet discharge head 1 includes a switching circuit element 8 and fifteen piezoelectric elements 13 including a first piezoelectric element 13a to a fifteenth piezoelectric element 13q. The switching circuit element 8 includes a synchronous distribution circuit 73 and 15 switch circuits 74 including a first switch circuit 74a to a fifteenth switch circuit 74q. The synchronous distribution circuit 73 receives the drive timing data output from the synchronous circuit 72, divides it into three drive timing signals, and outputs them to the three signal lines 75 of the first timing signal line 75a to the third timing signal line 75c. The first timing signal line 75a is connected to the first switch circuit 74a, the fourth switch circuit 74d, the seventh switch circuit 74g, the tenth switch circuit 74j, and the thirteenth switch circuit 74n, and the drive timing signal output from the synchronous distribution circuit 73. Is transmitted. The second timing signal line 75b is connected to the second switch circuit 74b, the fifth switch circuit 74e, the eighth switch circuit 74h, the eleventh switch circuit 74k, and the fourteenth switch circuit 74p, and the drive timing signal output from the synchronous distribution circuit 73. Is transmitted. Similarly, the third timing signal line 75c is connected to the third switch circuit 74c, the sixth switch circuit 74f, the ninth switch circuit 74i, the twelfth switch circuit 74m, and the fifteenth switch circuit 74q, and the synchronous distribution circuit 73 outputs. A drive timing signal is transmitted.

  The switch circuit 74 is electrically connected to the DA converter 71 via the five waveform signal lines 76 of the first waveform signal line 76a to the fifth waveform signal line 76e. The first switch circuit 74a to the third switch circuit 74c are connected to the first DA converter 71a via the first waveform signal line 76a, and the fourth switch circuit 74d to the sixth switch circuit 74f are connected to the second waveform signal line 76b. And is connected to the second DA converter 71b. Similarly, the seventh switch circuit 74g to the ninth switch circuit 74i are connected to the third DA converter 71c via the third waveform signal line 76c, and the tenth switch circuit 74j to the twelfth switch circuit 74m are the fourth waveform signal line 76d. And is connected to the fourth DA converter 71d. Further, the thirteenth switch circuit 74n to the fifteenth switch circuit 74q are connected to the fifth DA converter 71e via a fifth waveform signal line 76e. Each switch circuit 74 outputs a drive waveform in synchronization with the drive timing signal output from the synchronous distribution circuit 73.

  In the piezoelectric element 13, one piezoelectric element 13 is arranged corresponding to one nozzle 2. The first piezoelectric element 13a corresponds to the first nozzle 2a, and the second piezoelectric element 13b to the fifteenth piezoelectric element 13q correspond to the second nozzle 2b to the fifteenth nozzle 2q, respectively. The first switch circuit 74a is electrically connected to the first piezoelectric element 13a. Similarly, the second switch circuit 74b to the fifteenth switch circuit 74q are respectively connected to the second piezoelectric element 13b to the fifteenth piezoelectric element 13q. Electrically connected. Then, the piezoelectric element 13 connected to each switch circuit 74 is driven by the drive waveform output from each switch circuit 74.

  FIG. 5 is a time chart showing the signal flow of the head drive circuit and the droplet discharge head, and shows how the drive waveforms for driving the first piezoelectric element 13a to the third piezoelectric element 13c are output. The waveform shows a part of the drive waveform that is output continuously, and the waveforms when the first piezoelectric element 13a to the third piezoelectric element 13c are driven once each using FIG. 4 and FIG. To do. In FIG. 5, the vertical axis represents voltage, and the upper side in the figure is higher than the lower side. The horizontal axis shows the passage of time, and the time passes from the left side to the right side in the figure.

  The synchronization circuit output signal 79 on the upper side in the figure is a waveform that the synchronization circuit 72 outputs to the DA converter 71 and the synchronization distribution circuit 73. The synchronous circuit output signal 79 is composed of a pulse waveform, and each pulse waveform indicates the timing for driving the piezoelectric element 13. The first timing signal 80 to the third timing signal 82 are signals formed by the synchronization distribution circuit 73 by inputting the synchronization circuit output signal 79. The synchronization distribution circuit 73 generates the first timing signal line 75a to the third timing signal line. This signal is output to the first switch circuit 74a to the third switch circuit 74c via 75c.

  The first DA converter output signal 83 is a signal formed by DA converting the data received by the first DA converter 71a from the waveform dividing unit 70. The first DA converter 71a outputs the first DA converter output signal 83 to the first switch circuit 74a to the third switch circuit 74c via the first waveform signal line 76a. The first DA converter output signal 83 is configured by arranging three trapezoidal driving waveforms. The drive waveforms 83a to 83c constituting the first DA converter output signal 83 are waveforms for driving the first piezoelectric element 13a to the third piezoelectric element 13c, respectively. The drive waveforms 83a to 83c are formed in synchronization with the rising timing of the pulse waveform of the synchronous circuit output signal 79, respectively.

  The first switch circuit output signal 84 is a signal that the first switch circuit 74a outputs to the first piezoelectric element 13a. The first switch circuit 74a receives the first DA converter output signal 83 output from the first DA converter 71a and the first timing signal 80 output from the synchronous distribution circuit 73. Then, the drive waveform 83a having the same timing as the first timing signal 80 in the drive waveform of the first DA converter output signal 83 is output as the drive waveform 84a. The drive waveform 84a is input to the first piezoelectric element 13a to drive the first piezoelectric element 13a.

  Similarly, the second switch circuit output signal 85 is a signal that the second switch circuit 74b outputs to the second piezoelectric element 13b. Then, the drive waveform 83b having the same timing as the second timing signal 81 in the drive waveform of the first DA converter output signal 83 is output as the drive waveform 85a. Then, the drive waveform 85a is input to the second piezoelectric element 13b and drives the second piezoelectric element 13b.

  Similarly, the third switch circuit output signal 86 is a signal that the third switch circuit 74c outputs to the third piezoelectric element 13c. Then, the drive waveform 83c having the same timing as the third timing signal 82 among the drive waveforms of the first DA converter output signal 83 is output as the drive waveform 86a. The drive waveform 86a is input to the third piezoelectric element 13c and drives the third piezoelectric element 13c.

  That is, the switching circuit element 8 receives the synchronous circuit output signal 79 and the first DA converter output signal 83, and separates the first DA converter output signal 83 into the first switch circuit output signal 84 to the third switch circuit output signal 86. The switching circuit element 8 outputs the first switch circuit output signal 84 to the third switch circuit output signal 86 to the first piezoelectric element 13a to the third piezoelectric element 13c, respectively, so that the first piezoelectric element 13a to the third piezoelectric element are output. The element 13c is driven.

(Discharge rate inspection method)
Next, an inspection method for inspecting the ejection amount using the above-described ejection head inspection apparatus 18 will be described with reference to FIGS. FIG. 6 is a flowchart showing a manufacturing process for inspecting the discharge amount. 7 to 11 are views for explaining a discharge amount inspection method using the discharge head inspection apparatus.

  In FIG. 6, step S <b> 1 corresponds to a head placement process, which is a process of placing and fixing the droplet discharge head on the support base of the discharge head inspection apparatus. Next, the process proceeds to step S2. Step S2 corresponds to a substrate placement step, and is a step of fixing the substrate after mounting it on the mounting surface of the ejection head inspection apparatus. Next, the process proceeds to step S3. Step S3 corresponds to a table moving process, and is a process of driving the X table and the Y table to move the substrate to a location facing the droplet discharge head. Next, the process proceeds to step S4. Step S4 corresponds to the first discharge step, and is a step of discharging droplets onto the substrate. Next, the process proceeds to step S5. Step S5 corresponds to a table moving process, and is a process of driving the X table and the Y table to move the substrate to a location facing the imaging lens. Next, the process proceeds to step S6. Step S6 corresponds to the first measurement process, and is a process for measuring the volume of the droplets discharged onto the substrate. Next, the process proceeds to step S7. Step S7 corresponds to a calculation step and is a step of calculating an appropriate condition of the drive signal. Next, the process proceeds to step S8.

  Step S8 corresponds to a table moving process, and is a process of driving the X table and the Y table to move the substrate to a location facing the droplet discharge head. Next, the process proceeds to step S9. Step S9 corresponds to the second ejection step, and is a step of ejecting droplets onto the substrate using a drive signal with appropriate conditions. Next, the process proceeds to step S10. Step S10 corresponds to a table moving step, and is a step of driving the X table and the Y table to move the substrate to a location facing the imaging lens. Next, the process proceeds to step S11. Step S11 corresponds to the second measurement step, and is a step of measuring the volume of the droplets ejected on the substrate. Next, the process proceeds to step S12. Step S12 corresponds to a determination step, in which the pass / fail determination unit determines pass / fail of the droplet discharge head using the measured volume data of the droplets. Next, the process proceeds to step S13. Step S13 corresponds to a substrate removing process, and is a process of removing the substrate from the mounting surface. Next, the process proceeds to step S14. Step S14 corresponds to a head removing step, and is a step of removing the droplet discharge head from the support base. The manufacturing process for inspecting the discharge amount is completed by the above process.

  Next, the manufacturing method will be described in detail using FIGS. 7 to 11 in association with the steps shown in FIG. FIG. 7A is a diagram corresponding to step S1 and step S2. In step S1, the droplet discharge head 1 is placed on the upper surface 29a of the support base 29 as shown in FIG. A hole is formed in the shape of the droplet discharge head 1 in the support base 29, and the droplet discharge head 1 is inserted and placed in this hole. At this time, the droplet discharge head 1 is placed with the nozzle plate 3 facing the base 19, and the nozzle plate 3 is disposed so as to be positioned closer to the base 19 than the support base 29. The support base 29 is formed with a female screw at a location facing the mounting hole 5 a of the droplet discharge head 1. The droplet discharge head 1 is fixed to the support base 29 by passing a bolt through the mounting hole 5a and fastening the female screw.

  In step S <b> 2, the substrate 28 is placed on the placement surface 27 on the Y table 25. The substrate 28 is a substrate 28 that has been subjected to a liquid repellent treatment on one side with respect to the functional liquid 11, and the substrate 28 is disposed with the surface subjected to the liquid repellent treatment directed toward the droplet discharge head 1. A mark of the outer shape of the substrate 28 is formed on the placement surface 27 where the substrate 28 is placed, and the substrate 28 is placed on the placement surface 27 in accordance with the outer shape. Then, the substrate 28 is fixed using the substrate chuck mechanism.

  FIG. 7B is a diagram corresponding to step S3. As shown in FIG. 7B, the X table 22 and the Y table 25 are driven to move the substrate 28 to a location facing the droplet discharge head 1.

  FIG. 7C and FIG. 8A are diagrams corresponding to step S4. As shown in FIG. 7C, the droplet 14 is discharged from the droplet discharge head 1 onto the substrate 28. FIG. 8A is a time chart showing the flow of a drive signal, and shows drive waveforms for driving the first piezoelectric element 13a to the fifteenth piezoelectric element 13q. The waveform indicates a part of the continuously output drive waveform, and shows the waveform when the first piezoelectric element 13a to the fifteenth piezoelectric element 13q are driven once. In FIG. 8A, the vertical axis indicates the voltage, and the upper side in the figure is higher than the lower side. The horizontal axis shows the passage of time, and the time passes from the left side to the right side in the figure. The first switch circuit output signal 84 to the fifteenth switch circuit output signal 98 are signals output from the first switch circuit 74a to the fifteenth switch circuit 74q to the first piezoelectric element 13a to the fifteenth piezoelectric element 13q, respectively. These are signals for driving the first to fifteenth piezoelectric elements 13a to 13q.

  As shown in the figure, the first switch circuit output signal 84, the fourth switch circuit output signal 87, the seventh switch circuit output signal 90, the tenth switch circuit output signal 93, and the thirteenth switch circuit output signal 96 are output substantially simultaneously. The Then, after the first switch circuit output signal 84 is output, the second switch circuit output signal 85 is output after a predetermined time interval 99 has elapsed. At this time, the fifth switch circuit output signal 88, the eighth switch circuit output signal 91, the eleventh switch circuit output signal 94, and the fourteenth switch circuit output signal 97 are output simultaneously with the second switch circuit output signal 85.

  Similarly, after the second switch circuit output signal 85 is output, the third switch circuit output signal 86 is output after a predetermined time interval 99 has elapsed. At this time, the sixth switch circuit output signal 89, the ninth switch circuit output signal 92, the twelfth switch circuit output signal 95, and the fifteenth switch circuit output signal 98 are output simultaneously with the third switch circuit output signal 86.

  That is, the droplet discharge head 1 discharges the droplet 14 from the first nozzle 2a, the fourth nozzle 2d, the seventh nozzle 2g, the tenth nozzle 2j, and the thirteenth nozzle 2n. This nozzle 2 is defined as a first nozzle group. After the time interval 99 has elapsed, the droplet discharge head 1 discharges the droplets 14 from the second nozzle 2b, the fifth nozzle 2e, the eighth nozzle 2h, the eleventh nozzle 2k, and the fourteenth nozzle 2p. This nozzle 2 is defined as a second nozzle group. Furthermore, after the time interval 99 has elapsed, the droplet discharge head 1 discharges the droplets 14 from the third nozzle 2c, the sixth nozzle 2f, the ninth nozzle 2i, the twelfth nozzle 2m, and the fifteenth nozzle 2q. This nozzle 2 is defined as a third nozzle group. And let the droplet discharge element 15 corresponding to each nozzle group be a discharge element group.

  FIGS. 8B and 9A are diagrams corresponding to step S5 and step S6. In step S5, as shown in FIG. 8B, the X table 22 and the Y table 25 are driven to move the substrate 28 to a location facing the imaging lens 36. In step S <b> 6, the laser beam 102 is emitted from the illumination device 37. In the imaging lens 36, an objective lens 103, a half mirror 104, and an imaging lens 105 are arranged. The laser beam 102 emitted from the illumination device 37 goes straight and irradiates the half mirror 104. A part of the laser beam 102 that irradiates the half mirror 104 becomes a laser beam 102 a whose path is changed to the substrate 28 side by the half mirror 104. This laser beam 102 a passes through the objective lens 103 and irradiates the droplet 14. The laser beam 102 a that irradiates the droplet 14 is reflected by the droplet 14 and becomes a laser beam 102 b that has changed its course toward the imaging device 35. The laser beam 102 b passes through the objective lens 103, the half mirror 104, and the imaging lens 105 and forms an image on the imaging device 35.

  Part of the laser beam 102 irradiated by the illumination device 37 passes through the half mirror 104 and irradiates the mirror 106. The laser beam 102 that irradiates the mirror 106 is reflected by the mirror 106, and becomes a laser beam 102c whose path is changed to the half mirror 104. The laser beam 102c irradiates the half mirror 104. The laser beam 102 c that irradiates the half mirror 104 is reflected by the half mirror 104, and becomes a laser beam 102 d whose path is changed to the imaging device 35. The laser beam 102d passes through the imaging lens 105 and irradiates the imaging device 35. Since the laser beam 102b and the laser beam 102d that irradiate the imaging device 35 have the same wavelength and different phases, interference fringes are formed in the imaging device 35. The imaging device 35 transmits the image data of the interference fringes to the CPU 42. Then, the ejection amount measurement calculation unit 66 calculates the volume of the droplet 14 by analyzing the image data of the interference fringes.

  A linear motion mechanism 106a made of a piezoelectric element or the like is disposed on the opposite side of the mirror 106 from the illumination device 37, and the mirror 106 is movable in the traveling direction of the laser light 102c. The phase at which the laser beam 102d irradiates the imaging device 35 can be changed by moving the mirror 106. At this time, the shape of the droplet 14 can be accurately measured by using the change in the interference fringes formed by the laser light 102b and the laser light 102d.

  FIG. 9A is a diagram showing an example of discharge amount measurement data. The vertical axis represents the discharge amount 107, and the discharge amount 107 is larger on the upper side than on the lower side. The horizontal axis indicates the nozzle order 108. In this way, the measured value 109 of the discharge amount 107 for each nozzle 2 is obtained.

  FIG. 9B to FIG. 10B are diagrams corresponding to step S7. In step S7, an average value of the discharge amount for each of the first to third nozzle groups is calculated. FIG. 9B is a diagram illustrating an example of average discharge amount data of each nozzle group. The vertical axis indicates the average discharge amount 110, and the upper side is larger than the lower side. The horizontal axis indicates each nozzle group. The average discharge amounts 110 of the first nozzle group 111a to the third nozzle group 111c are defined as a first average discharge amount 112a to a third average discharge amount 112c. First, the nozzle group having the largest average discharge amount 110 among the first average discharge amount 112a to the third average discharge amount 112c is searched. In this example, the second average discharge amount 112b has the largest average discharge amount 110. Next, a first discharge amount difference 113a that is a difference between the second average discharge amount 112b and the first average discharge amount 112a is calculated. Similarly, a third discharge amount difference 113c that is a difference between the second average discharge amount 112b and the third average discharge amount 112c is calculated.

  FIG. 9C is a diagram illustrating the relationship between the drive voltage and the ejection amount in the drive element. The vertical axis indicates the discharge amount 107, and the upper side is larger than the lower side. The horizontal axis indicates the drive voltage 114, and the right side is higher than the left side. A correlation curve 115 shows the relationship between the drive voltage 114 and the ejection amount 107. As indicated by the correlation curve 115, the ejection amount 107 increases as the drive voltage 114 increases. The correlation curve 115 is calculated by driving a number of droplet discharge heads 1 in advance and measuring the relationship between the drive voltage 114 and the discharge amount 107 and then performing an average calculation.

  In step S4, the driving voltage 114 when driving the piezoelectric element 13 is set as the second driving voltage 114a. In the correlation curve 115, the discharge amount 107 corresponding to the second drive voltage 114a is set as the basic discharge amount 107a. A discharge amount 107 obtained by adding the first discharge amount difference 113a to the basic discharge amount 107a is defined as a first simulated discharge amount 107b. In the correlation curve 115, the drive voltage 114 corresponding to the first simulated discharge amount 107b is defined as the first drive voltage 114b.

  Similarly, a discharge amount 107 obtained by adding a third discharge amount difference 113c to the basic discharge amount 107a is set as a third simulated discharge amount 107c. In the correlation curve 115, the drive voltage 114 corresponding to the third simulated discharge amount 107c is set as the third drive voltage 114c. In this way, the drive voltage 114 is set to an appropriate condition.

  When the piezoelectric element 13 of the first nozzle group 111a is driven with the first drive voltage 114b, the drive voltage 114 is set higher, so the average discharge amount 110 corresponds to the first discharge amount difference 113a than the discharge amount 107 in step S4. The amount to be expected is expected to increase. Similarly, when the piezoelectric element 13 of the third nozzle group 111c is driven with the third drive voltage 114c, the drive voltage 114 is set higher, so the average discharge amount 110 is different from the discharge amount 107 in step S4 by the third discharge amount difference. It is expected to increase by an amount corresponding to 113c. FIG. 10A is an average discharge amount assumption diagram at the changed drive voltage. The vertical axis and horizontal axis in FIG. 10A are the same as those in FIG. It is assumed that the first discharge estimated amount 116a to the third discharge estimated amount 116c, which is the average discharge amount 110 of the first nozzle group 111a to the third nozzle group 111c, are substantially the same amount.

  FIG. 10B is a diagram illustrating an example of ejection amount estimation data. The vertical axis and the horizontal axis in FIG. 10B are the same as those in FIG. Then, the first discharge amount difference 113a is added to the discharge amount 107 of the first nozzle group 111a, and the third discharge amount difference 113c is added to the discharge amount 107 of the third nozzle group 111c to estimate the discharge at each nozzle 2. The quantity 117 is calculated. As shown in the figure, when the calculated estimated discharge amount 117 is plotted in the nozzle order 108, the estimated discharge amount 117 is arranged on a line similar to a quadratic curve.

  Next, each nozzle 2 is classified into three groups based on the estimated ejection amount 117. First, the first classification threshold 119a to the fourth classification threshold 119d are set at the classification interval 118 as the same offset value. The nozzle 2 having the estimated ejection amount 117 between the first classification threshold value 119a and the second classification threshold value 119b is defined as a first ejection amount group 120a. The fifth nozzle 2e to the eleventh nozzle 2k correspond to the first discharge amount group 120a. Next, the nozzle 2 in which the estimated ejection amount 117 is between the second classification threshold value 119b and the third classification threshold value 119c is set as the second ejection amount group 120b. The third nozzle 2c, the fourth nozzle 2d, the twelfth nozzle 2m, the thirteenth nozzle 2n, and the fourteenth nozzle 2p correspond to the second discharge amount group 120b. Subsequently, the nozzle 2 whose estimated ejection amount 117 is between the third classification threshold value 119c and the fourth classification threshold value 119d is defined as a third ejection amount group 120c. The first nozzle 2a, the second nozzle 2b, and the fifteenth nozzle 2q correspond to the third discharge amount group 120c.

  Next, the drive voltage 114 is changed with reference to the correlation curve 115 shown in FIG. At this time, the drive voltage 114 of the piezoelectric element 13 belonging to the first ejection amount group 120a is not changed. Then, the driving voltage 114 of the piezoelectric elements 13 belonging to the second ejection amount group 120b is lowered by the classification interval 118 to the driving voltage 114 corresponding to the ejection amount 107. Similarly, the driving voltage 114 of the piezoelectric elements 13 belonging to the third ejection amount group 120c lowers the driving voltage 114 corresponding to the ejection amount 107 twice the classification interval 118. By this voltage adjustment, the drive voltage 114 is adjusted to an appropriate condition.

  FIG. 10C is a diagram showing an example of ejection amount estimation data. The vertical axis and horizontal axis in FIG. 10C are the same as those in FIG. The estimated ejection amount 121 is an amount obtained by estimating the ejection amount 107 after the drive voltage 114 is adjusted. As shown in the figure, the estimated ejection amount 121 is plotted between the first classification threshold value 119a and the second classification threshold value 119b.

  In step S8, as in step S3, the X table 22 and the Y table 25 are driven as shown in FIG. 7B to move the substrate 28 to a location facing the droplet discharge head 1. In step S9, as in step S4, the droplet 14 is ejected from the droplet ejection head 1 onto the substrate 28 as shown in FIG. 7C. At this time, it discharges to a place different from the place discharged in step S4. The driving voltage for driving the piezoelectric element 13 is a driving voltage under the appropriate conditions calculated in step S7. In the next step S10, as in step S5, the X table 22 and the Y table 25 are driven as shown in FIG. 8B to move the substrate 28 to a location facing the imaging lens 36.

  In step S11, the volume of the droplet 14 is measured as in step S6. FIG. 11 is a diagram corresponding to step S11 and step S12, and is a diagram illustrating an example of discharge amount measurement data. As shown in the figure, the measured value 122 of the discharge amount 107 in each nozzle 2 is plotted. In step S12, the quality determination unit 68 compares the measured value 122 with the lower standard value 123a and the upper standard value 123b. When the measured value 122 is between the lower standard value 123a and the upper standard value 123b, the quality determination unit 68 determines that the droplet discharge head 1 is a non-defective product. Then, the quality determination unit 68 determines that the droplet discharge head 1 that is not determined to be a non-defective product is a defective product.

  Next, in step S13, the substrate 28 is removed from the mounting surface 27, and in step S14, the droplet discharge head 1 is removed from the support base 29. With the above process, the manufacturing process for inspecting the discharge amount is completed.

As described above, the present embodiment has the following effects.
(1) According to this embodiment, after measuring the discharge amount 107 for each nozzle 2, the average discharge amount 110 for each nozzle group of the first nozzle group 111a to the third nozzle group 111c is calculated. And after calculating the appropriate condition of a drive signal using the average discharge amount 110, it discharges with the drive signal of an appropriate condition. Next, pass / fail is determined based on the discharge amount 107 at the drive voltage 114 under appropriate conditions. Therefore, the quality of the plurality of droplet discharge elements 15 can be determined based on the discharge amount 107 under the appropriate conditions, so that the quality can be determined with high accuracy.

  (2) According to the present embodiment, whether or not the average discharge amount 110 of the first nozzle group 111a to the third nozzle group 111c is substantially the same is determined. Therefore, it is possible to determine whether or not the ejection head is good while the difference in the ejection amount 107 between the first nozzle group 111a and the third nozzle group 111c is small.

  (3) According to the present embodiment, ejection is performed using a drive signal under appropriate conditions in which the ejection amount 107 corresponding to the classification interval 118 or twice the classification interval 118 is adjusted. Then, pass / fail judgment is made in a state where the dispersion of the ejection amount 107 in each droplet ejection element 15 is small. Therefore, it is possible to determine whether the droplet discharge head 1 is good or bad when the droplet discharge element 15 is driven with a drive signal under an appropriate condition for reducing the dispersion of the discharge amount 107 of the droplet discharge element 15.

(Second Embodiment)
Next, an embodiment of a droplet discharge device will be described with reference to FIGS. FIG. 12 is a schematic perspective view showing the configuration of the droplet discharge device, and FIG. 13 is an electric control block diagram of the droplet discharge device. FIG. 14 is a flowchart showing the manufacturing process for applying the functional liquid to the substrate. This embodiment is different from the first embodiment in that a method of driving the droplet discharge head 1 with a drive signal of an appropriate condition is applied to a droplet discharge device. Note that description of the same points as in the first embodiment is omitted.

  That is, in the present embodiment, the droplets 14 are ejected to the droplet ejection device 126 shown in FIG. 12 using the droplet ejection head 1 in the first embodiment. As shown in FIG. 12, the droplet discharge device 126 includes a base 127 formed in a rectangular parallelepiped shape. In the present embodiment, the longitudinal direction of the base 127 is the Y direction, and the direction orthogonal to the Y direction is the X direction.

  On the upper surface 127a of the base 127, a pair of guide rails 128a and 128b extending in the Y direction is provided so as to protrude over the entire width in the Y direction. On the upper side of the base 127, a stage 129 constituting a scanning means provided with a linear motion mechanism (not shown) corresponding to the pair of guide rails 128a and 128b is attached. The linear movement mechanism of the stage 129 is, for example, a screw type linear movement mechanism including a screw shaft (drive shaft) extending in the Y direction along the guide rails 128a and 128b and a ball nut screwed to the screw shaft. The drive shaft is connected to a Y-axis motor (not shown) that receives a predetermined pulse signal and rotates forward and backward in units of steps. When a drive signal corresponding to a predetermined number of steps is input to the Y-axis motor, the Y-axis motor rotates forward or reversely, and the stage 129 corresponds to the same number of steps along the Y-axis direction. The robot moves forward or backward (scans in the Y direction) at a predetermined speed.

  Further, a main scanning position detection device 130 is arranged on the upper surface 127a of the base 127 in parallel with the guide rails 128a and 128b so that the position of the stage 129 can be measured.

  A placement surface 131 is formed on the upper surface of the stage 129, and a suction-type substrate chuck mechanism (not shown) is provided on the placement surface 131. When a substrate 132 as a workpiece is placed on the placement surface 131, the substrate 132 is positioned and fixed at a predetermined position on the placement surface 131 by a substrate chuck mechanism.

  A pair of support bases 133a and 133b are erected on both sides in the X direction of the base 127, and a guide member 134 extending in the X direction is installed on the pair of support bases 133a and 133b. The guide member 134 is formed so that the width in the longitudinal direction is longer than the X direction of the stage 129, and one end of the guide member 134 is projected to the support base 133 a side.

  On the upper side of the guide member 134, a storage tank 135 for storing the discharged functional liquid 11 is provided. On the other hand, a guide rail 136 extending in the X direction is provided below the guide member 134 so as to protrude over the entire width in the X direction.

  The carriage 137 disposed so as to be movable along the guide rail 136 is formed in a substantially rectangular parallelepiped shape. The linear movement mechanism of the carriage 137 is, for example, a screw type linear movement mechanism including a screw shaft (drive shaft) extending in the X direction along the guide rail 136 and a ball nut screwed to the screw shaft. The drive shaft is connected to an X-axis motor (not shown) that receives a predetermined pulse signal and rotates forward and backward in steps. When a drive signal corresponding to a predetermined number of steps is input to the X-axis motor, the X-axis motor rotates forward or backward, and the carriage 137 moves forward or backward along the X direction by the amount corresponding to the same number of steps. Move (scan in X direction). A sub-scanning position detection device 138 is disposed between the guide member 134 and the carriage 137 so that the position of the carriage 137 can be measured. Then, on the lower surface of the carriage 137 (the surface on the stage 129 side), the droplet discharge heads 1 are projected in three rows parallel to each other in the X direction.

  A maintenance table 139 is arranged on the side of the base 127 opposite to the X direction, and an electronic balance 140 is arranged on the maintenance table 139 in the moving range of the carriage 137. The discharge amount of the functional liquid 11 discharged from the droplet discharge head 1 can be measured. The electronic balance 140 includes a measurement tray at a position facing the droplet discharge head 1, and receives the droplet 14 discharged from the droplet discharge head 1 by the measurement tray and measures the weight. The measurement saucer is provided with a sponge-like absorber, and the droplets ejected from the droplet ejection head 1 are prevented from splashing and flying out of the measurement saucer.

  FIG. 13 is an electric control block diagram of the droplet discharge device. In FIG. 13, the droplet discharge device 126 includes a control device 143 that controls the operation of the droplet discharge device 126, and the control device 143 functions as a CPU (arithmetic processing device) 144 that performs various types of arithmetic processing, and various information. And a memory 145 for storing.

  The main scanning drive device 146, the main scanning position detection device 130, the sub scanning drive device 147, the sub scanning position detection device 138, the head drive circuit 148 that drives the droplet discharge head 1, the input / output interface 149 and the data bus 150. It is connected to the CPU 144 via. Further, the input device 151, the display device 152, and the electronic balance 140 are also connected to the CPU 144 via the input / output interface 149 and the data bus 150.

  The main scanning drive device 146 is a device that controls the movement of the stage 129, and the sub-scanning drive device 147 is a device that controls the movement of the carriage 137. The main scanning position detection device 130 recognizes the position of the stage 129 and the main scanning driving device 146 controls the movement of the stage 129, so that the stage 129 can be moved and stopped to a desired position. Similarly, the sub-scanning position detecting device 138 recognizes the position of the carriage 137 and the sub-scanning driving device 147 controls the movement of the carriage 137, so that the carriage 137 can be moved to a desired position and stopped. Yes.

  The input device 151 is a device that inputs various processing conditions for ejecting the droplets 14. For example, the input device 151 is a device that receives and inputs coordinates for ejecting the droplets 14 onto the substrate 132 from an external device (not shown). The display device 152 is a device that displays processing conditions and work status, and an operator performs an operation using the input device 151 based on information displayed on the display device 152.

  The electronic balance 140 is a device that includes a tray and measures the weight of the droplets 14 ejected by the droplet ejection head 1 and the tray that receives the droplets 14. The electronic balance 140 measures the weight of the saucer before and after the droplet 14 is discharged, and transmits the measured value to the CPU 144.

  The memory 145 is a concept including a semiconductor memory such as a RAM and a ROM, and an external storage device such as a hard disk and a CD-ROM. Functionally, a storage area for storing program software 153 in which a control procedure of the operation of the droplet discharge device 126 is described, and a storage for storing discharge position data 154 that is coordinate data of the discharge position in the substrate 132. An area is set. In addition, a storage area for storing drive signal data 155 that is a drive signal when driving the droplet discharge head 1, and discharge amount measurement data 156 that is measurement data of the discharge amount of the droplet discharge head 1. A storage area is set. In addition, a work area for the CPU 144, a storage area that functions as a temporary file, and other various storage areas are set.

  The CPU 144 performs control for discharging the functional liquid 11 to a predetermined position on the surface of the substrate 132 according to the program software 153 stored in the memory 145. As a specific function realization unit, there is a discharge amount measurement calculation unit 157 that performs calculation for realizing measurement of the discharge amount using the electronic balance 140, an appropriate condition calculation unit 158 that calculates an appropriate condition of the drive signal, and the like. . Furthermore, it has a discharge calculation unit 159 that performs a calculation for discharging the droplet 14 from the droplet discharge head 1.

  If the discharge calculation unit 159 is divided in detail, a main scanning control calculation unit 160 that calculates control for scanning and moving the substrate 132 in the main scanning direction at a predetermined speed, and a predetermined sub scanning amount in the sub scanning direction. And a sub-scanning control calculation unit 161 for calculating control for moving the image. Further, the discharge calculation unit 159 performs various functional calculations such as a discharge control calculation unit 162 that performs calculation for controlling which of the plurality of nozzles in the droplet discharge head 1 is operated to discharge the functional liquid. Part.

  In the present embodiment, each function described above is realized by program software using the CPU 144. However, when each function described above can be realized by a single electronic circuit (hardware) that does not use the CPU, It is also possible to use such an electronic circuit.

  Next, a manufacturing method for applying the functional liquid 11 to the substrate 132 using the above-described droplet discharge device 126 will be described with reference to FIG. FIG. 14 is a flowchart showing a manufacturing process for applying a functional liquid to a substrate. A manufacturing process is demonstrated using the flowchart of FIG. Step S21 corresponds to a head placement step, and is a step of placing the droplet discharge head 1 on the droplet discharge device 126. Next, the process proceeds to step S22. Step S22 is a process corresponding to a discharge amount measurement process. In this step, the droplet discharge head 1 is moved to a location facing the electronic balance 140, and the droplet 14 is discharged from the droplet discharge head 1 to the electronic balance 140. Then, the weight of the droplet 14 discharged from each nozzle 2 is measured. For example, 2000 discharges are performed from one nozzle 2, and the weight of the discharged functional liquid 11 is measured. Then, the discharge amount per time is calculated by dividing the weight by 2000 which is the number of times of discharge. This method is carried out for all nozzles 2. Then, a distribution of the discharge amount 107 as shown in FIG. 9 is obtained. Next, the process proceeds to step S23.

  Step S23 corresponds to a calculation process and is a process of calculating an appropriate condition of the drive signal. In this step, first, as shown in FIG. 9B, the average discharge amount 110 of the first nozzle group 111a to the third nozzle group 111c is calculated to calculate the discharge amount difference between the nozzle groups. Then, an appropriate condition for the drive voltage 114 for each nozzle group is calculated using the correlation curve 115 shown in FIG.

  Next, as shown in FIG. 10B, each nozzle 2 is classified into a first discharge amount group 120a to a third discharge amount group 120c. Then, using the correlation curve 115 shown in FIG. 9C, appropriate conditions for the drive voltage 114 are calculated and set so that the dispersion of the ejection amount 107 becomes small. Next, the process proceeds to step S24. Step S24 is a process corresponding to a drawing process. In this step, the functional liquid 11 is discharged as droplets 14 onto the substrate 132 according to the drawing pattern stored in the discharge position data 154. Then, the functional liquid 11 is applied to the substrate 132. When the functional liquid 11 is applied to the shape of the planned drawing pattern, the ejection of the droplets 14 is stopped. The manufacturing process for applying the functional liquid 11 to the substrate 132 is completed by the above process.

As described above, this embodiment has the following effects.
(1) According to this embodiment, after measuring the discharge amount 107 for each nozzle, the average discharge amount 110 for each nozzle group is calculated. Then, after calculating the appropriate condition of the drive voltage using the average discharge amount 110, the discharge is performed by the drive signal of the appropriate condition. Next, drawing is performed based on the ejection amount 107 in the drive signal under the appropriate conditions. Accordingly, since the plurality of ejection element groups are drawn based on the ejection amount under the appropriate conditions, it is possible to perform the rendering by ejecting the droplets 14 with the ejection amount 107 with high accuracy.

  (2) According to the present embodiment, rendering is performed in a state where the dispersion of the ejection amount 107 in each ejection element group is small. Therefore, it is possible to draw and draw the droplets 14 with a precise discharge amount 107.

The present invention is not limited to the above-described embodiment, and various changes and improvements can be added. A modification will be described below.
(Modification 1)
In the first embodiment, in step S7, the average value of the discharge amount 107 is calculated to calculate the difference between the nozzle groups. Statistical methods other than the average value may be used. For example, a median value or mode value in the nozzle group may be employed. By simplifying the calculation, it can be easily calculated.

(Modification 2)
In the first embodiment, in step S4, the droplet discharge head 1 may be warmed up before the measurement discharge is performed. Since the state of the droplet discharge head 1 is close to the state of driving at the time of drawing, the inspection can be performed in a state close to the driving condition at the time of drawing.

(Modification 3)
In the first embodiment, in FIG. 10B, the voltage for driving the piezoelectric element 13 of the nozzle 2 having a large discharge amount 107 is lowered to match the discharge amount 107 with the first discharge amount group 120a. The amount 107 dispersion was reduced. However, the dispersion of the discharge amount 107 may be reduced by increasing the voltage for driving the piezoelectric element 13 of the nozzle 2 having a small discharge amount 107 to match the third discharge amount group 120c. In addition, the voltage for driving the piezoelectric element 13 of the nozzle 2 corresponding to the first discharge amount group 120a is increased, and the voltage for driving the piezoelectric element 13 of the nozzle 2 corresponding to the third discharge amount group 120c is decreased, The dispersion of the discharge amount 107 may be reduced by matching with the second discharge amount group 120b. In either case, the dispersion of the discharge amount 107 can be reduced.

(Modification 4)
In the first embodiment, the piezoelectric element 13 is used as the pressurizing means for pressurizing the cavity 10, but other methods may be used. For example, the diaphragm 12 may be deformed and pressurized using a coil and a magnet. In addition, a heater wiring may be disposed in the cavity 10 to expand and pressurize the gas contained in the functional liquid 11. In addition, the diaphragm 12 may be deformed and pressurized using electrostatic attraction and repulsion. In any case, the same effect as in the above embodiment can be obtained by calculating and discharging the appropriate condition of the drive signal.

(Modification 5)
In the second embodiment, the functional liquid 11 is applied by being discharged onto the substrate 132. However, the workpiece to be applied is not limited to the substrate 132, and an object having a height in the Z direction such as a rectangular parallelepiped or an object having unevenness. It can also be applied to.

(Modification 6)
In the first embodiment, the nozzle 2 of the first nozzle group 111a, the nozzle 2 of the second nozzle group 111b, and the nozzle 2 of the third nozzle group 111c are arranged in this order, but the arrangement order is not limited to this. The above method may be used with the nozzles 2 that discharge simultaneously as the same nozzle group. Similar effects can be obtained.

1A is a schematic perspective view illustrating a configuration of a droplet discharge head, FIG. 2B is a diagram illustrating a nozzle plate, and FIG. 3C is a diagram for explaining a structure of the droplet discharge head. FIG. FIG. 2 is a schematic perspective view illustrating a configuration of a discharge head inspection apparatus. The electric control block diagram of a droplet discharge position measuring apparatus. FIG. 3 is an electrical control block diagram of a head driving circuit and a droplet discharge head. 4 is a time chart showing signal flows of a head drive circuit and a droplet discharge head. The flowchart which shows the manufacturing process which test | inspects discharge amount. The figure explaining the inspection method of the discharge amount using a discharge head test | inspection apparatus. (A) is a time chart showing the flow of a drive signal, (b) is a diagram for explaining an ejection amount inspection method using an ejection head inspection apparatus. (A) is a figure which shows an example of the measurement data of discharge amount, (b) is a figure which shows an example of the average discharge amount data of each nozzle group, (c) is the relationship between the drive voltage and discharge amount in a drive element. FIG. (A) is an average discharge amount assumption figure in the drive voltage after a change, (b) And (c) is a figure which shows an example of the estimation data of discharge amount. The figure which shows an example of the measurement data of discharge amount. The schematic perspective view which shows the structure of the droplet discharge apparatus which concerns on 2nd Embodiment. The electric control block diagram of a droplet discharge device. The flowchart which shows the manufacturing process which apply | coats a functional liquid to a board | substrate.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Droplet discharge head as a discharge head, 2 ... Nozzle, 2a ... 1st nozzle as a nozzle, 2b ... 2nd nozzle as a nozzle, 2c ... 3rd nozzle as a nozzle, 2d ... 4th nozzle as a nozzle 2e: a fifth nozzle as a nozzle, 2f: a sixth nozzle as a nozzle, 2g: a seventh nozzle as a nozzle, 2h: an eighth nozzle as a nozzle, 2i: a ninth nozzle as a nozzle, 2j: as a nozzle 10th nozzle, 2k ... 11th nozzle as nozzle, 2m ... 12th nozzle as nozzle, 2n ... 13th nozzle as nozzle, 2p ... 14th nozzle as nozzle, 2q ... 15th nozzle as nozzle, DESCRIPTION OF SYMBOLS 11 ... Functional liquid as a liquid body, 14 ... Droplet as an ejection element, 18 ... Discharge head test | inspection apparatus, 35 ... Imaging device as a measurement part, 63 ... Drive signal Forming unit, 67 ... proper condition calculation unit, 107 ... discharge amount, 118 ... classification distance as the offset value, the substrate as 132 ... work.

Claims (7)

A method for inspecting a discharge head for driving a plurality of discharge element groups to discharge a liquid material from nozzles of the discharge elements,
A first discharge step of driving the plurality of discharge element groups to discharge the liquid material;
A first measurement step of measuring a discharge amount of the liquid material discharged in the first discharge step;
A calculation step of calculating a statistical value of the discharge amount measured in the first measurement step for each of the discharge element groups, and calculating an appropriate condition of a drive signal corresponding to the discharge element group based on the statistical value;
A second discharge step of discharging the liquid material by driving a plurality of the discharge element groups by the drive signal of the appropriate condition;
A second measurement step of measuring a discharge amount of the liquid material discharged in the second discharge step;
And a determination step of determining pass / fail of the discharge head based on the discharge amount measured in the second measurement step for each of the discharge element groups.   The discharge head inspection method according to claim 1, wherein the statistical value calculated in the calculation step is an average value, and the appropriate condition is that the average value of the discharge amount for each of the discharge element groups is substantially the same. An ejection head inspection method, wherein the ejection head is calculated to be An inspection method for a discharge head according to claim 2,
The ejection head inspection method, wherein the appropriate condition of the drive signal is calculated by adding or subtracting an offset value to the drive signal so that dispersion of the ejection amount in each ejection element is reduced. An ejection head inspection apparatus that drives a plurality of ejection element groups to eject a liquid material from nozzles of the ejection elements,
A drive signal forming unit for forming a drive signal for driving the ejection element;
A measurement unit for measuring the discharge amount of the liquid material discharged from the nozzle;
An appropriate condition calculation unit that calculates a statistical value of the discharge amount for each of the discharge element groups, and calculates an appropriate condition of the drive signal corresponding to each of the discharge element groups based on the statistical value;
An ejection head inspection apparatus, comprising: a quality determination unit that determines quality of the ejection head based on an ejection amount in the ejection head.   5. The ejection head inspection apparatus according to claim 4, wherein the statistical value calculated by the appropriate condition calculation unit is an average value, and the average value of the discharge amount for each of the discharge element groups is substantially the same in the appropriate condition. An ejection head inspection apparatus characterized by being calculated to be The discharge head inspection apparatus according to claim 5,
2. The ejection head inspection apparatus according to claim 1, wherein the appropriate condition of the drive signal is calculated by adding or subtracting an offset value to the drive signal so that dispersion of the ejection amount in each ejection element group is reduced. A drawing method of driving a plurality of ejection element groups to eject a liquid material from a nozzle of the ejection element onto a work,
A discharge amount measuring step of driving a plurality of the discharge element groups to discharge the liquid material and measuring a discharge amount;
A calculation step of calculating a statistical value of the discharge amount measured in the discharge amount measurement step for each discharge element group, and calculating an appropriate condition of a drive signal corresponding to the discharge element group based on the statistical value;
And a drawing step of drawing by drawing the liquid material onto the workpiece.

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