JP6876487B2 - Inspection device, inspection method, functional liquid discharge device and correction method - Google Patents

Description

The present invention relates to an inspection device, an inspection method , a functional liquid discharge device, and a correction method for inspecting a state of discharge of functional liquid from a nozzle.

Conventionally, an organic light emitting diode (OLED), which is a light emitting diode utilizing light emission of organic EL (Electroluminescence), is known. An organic EL display using such an organic light emitting diode has advantages such as thinness, light weight, low power consumption, and excellent response speed, viewing angle, and contrast ratio. Therefore, it is a next-generation flat. In recent years, it has been attracting attention as a panel display (FPD).

The organic light emitting diode has a structure in which an organic EL layer is sandwiched between an anode and a cathode on a substrate. The organic EL layer is formed by laminating, for example, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer in this order from the anode side. In forming each of these organic EL layers (particularly the hole injection layer, the hole transport layer and the light emitting layer), a method of ejecting a functional liquid of an organic material onto a substrate by, for example, an inkjet method is used.

By the way, in the organic light emitting diode, each layer of the organic EL layer is formed of a thin film having a thickness of several tens of nm. Therefore, if, for example, a defective discharge of a functional liquid occurs in any of the layers, the influence thereof causes the product to operate. In that case, it will appear prominently. Therefore, in order to suppress such defective discharge of the functional liquid, the state of the droplets formed by the functional liquid discharged on the ejected body such as the inspection substrate or the inspection sheet was observed, and the functional liquid was discharged. It is necessary to inspect the state of the nozzle, that is, the discharge state of the functional liquid, and correct the discharge condition based on the inspection result. The ejected body at the time of the above correction is, for example, an inspection substrate or an inspection sheet.

Patent Document 1 discloses an apparatus for inspecting a discharge state of a functional liquid based on the state of a droplet formed by the above-mentioned inkjet method, and the apparatus images a functional droplet landed on an inspection substrate. It includes an imaging means, an analysis means for analyzing the diameter of the droplet using an image of the captured droplet, and a calculation means for calculating the volume of the functional droplet based on the diameter of the functional droplet and the like. Further, Patent Document 1 discloses that the driving waveform of the driving element of the nozzle, that is, the ejection condition is controlled based on the calculated volume of the functional droplet.

However, due to the nature of the functional liquid (ink), dirt on the nozzle, etc., the droplets often do not have an appropriate shape (for example, a perfect circle). If the droplets are not in the proper shape, the ejection conditions cannot be corrected based on the inspection results. Even if it is corrected, a good result cannot be obtained after the correction.

On the other hand, Patent Document 2 describes a functional liquid discharge method in which a function is discharged from a plurality of nozzles provided in a functional liquid discharge head to form droplets of the functional liquid on a substrate, and the liquid is discharged from each nozzle for inspection. The matching rate reaches the threshold value by comparing the outer shape of the image of each droplet acquired in the imaging process with the image of each droplet landed on the substrate with the outer shape of a perfect circle of the normal pattern. The landing area of the functional liquid is obtained based on the image processing step of selecting an image whose matching rate has reached the threshold as a normal image and the image selected as a normal image in the image processing step. By having a control step of controlling the discharge amount of the functional liquid from the nozzle that discharges the functional liquid based on the area, the discharge amount of the functional liquid, that is, the discharge condition can be appropriately corrected.

Japanese Unexamined Patent Publication No. 2005-119139 Japanese Unexamined Patent Publication No. 2010-188263

In the method described in Patent Document 2, as shown in FIG. 9A, if the state of the nozzle or the like is normal and the external shape of the image of the droplet (image taken) L1 to be imaged is a perfect circle, the image L1 Is determined to be a normal pattern. Further, as shown in FIG. 9B, if the state of the nozzle or the like is not normal and the outer shape of the captured image L1 of the droplet is not a perfect circle, the image L1 is determined to be an abnormal pattern, and FIG. 9C ), But the state of the nozzle is normal, but the external shape of the captured image L1 of the droplet is not a perfect circle due to the presence of foreign matter C1 in the droplet, the image L1 is an abnormal pattern. Is determined. However, in the method described in Patent Document 2, as shown in FIG. 9D, although the state of the nozzle is normal, the foreign matter C1 is present in the droplet, but the outer shape of the captured image L1 of the droplet is If it becomes a perfect circle, it will be judged as a normal pattern. Since the droplets are formed larger due to the presence of the foreign matter C1, if the captured image L1 of the droplet containing the foreign matter C1 is included as a normal pattern and the ejection conditions based on the captured image are corrected, the correction cannot be performed appropriately. ..
The same applies to the case where droplets are formed not on the foreign matter C1 but on a portion where scratches or the like are present on the ejected body such as an inspection sheet.

Further, when a lipophilic test sheet is used as the ejected body, as shown in FIG. 10A, when everything is normal such as the state of the nozzle depending on the functional liquid, an image of the droplet is captured. L2 may be a double concentric circle.
In the method described in Patent Document 2, since the image L2 in FIG. 10 (A) has a perfect circular outer shape, it is determined that the image L2 has a normal pattern, and as shown in FIG. 10 (B), the image L2 is determined to have a normal pattern. The captured image L2 of the droplet whose outer shape is not a perfect circle is determined to be an abnormal pattern because the center of the small circle deviates greatly from the center of the great circle. However, in the method described in Patent Document 2, the captured image L2, which is a non-concentric double circle and has a perfect outer shape as shown in FIG. 10C, is determined to be a normal pattern.
Since the permeation mode of the functional liquid into the lipophilic test sheet differs between the case where the captured image L2 of FIG. 10 (A) is obtained and the case where the captured image L2 of FIG. 10 (C) is obtained, these In some cases, even if the captured image area is the same, the amount of the functional liquid that has permeated the inspection sheet, that is, the discharge amount of the functional liquid is different. Therefore, if the ejection conditions based on the captured image are corrected using the captured image L2 of FIG. 10C as a normal pattern, the correction cannot be performed appropriately.

The present invention has been made in view of this point, and it is possible to more appropriately correct the discharge condition of the functional liquid based on the inspection result of the discharge state of the functional liquid using the imaging result of the functional droplet. The purpose is to be able to do it.

The present invention that solves the above problems is an inspection device that inspects the discharge state of the functional liquid from the nozzle, and images a plurality of droplets formed on the ejected body by the functional liquid discharged from the nozzle. The imaging unit, the measuring unit that measures the formation state of the droplet based on the imaging result of the imaging unit, the entire image captured by the imaging unit, and a predetermined form for each of the plurality of droplets. It has a selection unit that performs pattern matching with the entire image of the droplets to be possessed and selects a droplet to be measured by the measurement unit from the plurality of droplets based on the matching result, and the predetermined form. It is characterized by including a reference image selection unit for selecting an image of a droplet from among the captured images of the plurality of droplets imaged by the imaging unit.

The captured image and the image of the droplet having the predetermined form are preferably grayscale images represented by 256 gradations.

The captured image and the image of the droplet having the predetermined form are preferably color images in which each color is represented by 256 gradations.

According to the present invention from another viewpoint, the plurality of the nozzles, the inspection device, and the measuring unit for each of the nozzles are selected as the droplets to be measured by the measuring unit. A functional liquid discharge device including a control unit for correcting the discharge condition of the functional liquid based on the measurement result of the above is provided.

According to the present invention from yet another viewpoint, it is an inspection method for inspecting the discharge state of the functional liquid from the nozzle, and a plurality of droplets formed on the ejected body by the functional liquid discharged from the nozzle are formed. For each of the step of imaging by the imaging unit and the plurality of droplets, pattern matching is performed between the entire image captured by the imaging unit and the entire image of the droplet having a predetermined shape, and based on the matching result, the said A step of selecting a droplet to be measured from a plurality of droplets, and a step of measuring the formation state of the selected droplet to be measured based on the imaging result of the imaging unit. only contains the image of the droplets having the predetermined configuration, it is characterized in further including Mukoto the step of selecting from among the captured images of the plurality of droplets captured by the imaging unit.
According to the present invention from yet another viewpoint, it is a method of correcting the discharge condition of the functional liquid from the nozzle, and images a plurality of droplets formed on the ejected body by the functional liquid discharged from the nozzle. For each of the step of imaging by the unit and the plurality of droplets, pattern matching is performed between the entire image captured by the imaging unit and the entire image of the droplet having a predetermined shape, and based on the matching result, the plurality of droplets are imaged. A step of selecting a droplet to be measured from among the droplets of the above, a step of measuring the formation state of the selected droplet to be measured based on the imaging result of the imaging unit, and the step described above. For each nozzle, the selected droplet to be measured includes a step of correcting the discharge condition of the functional liquid based on the measurement result in the measurement step, and the droplet has the predetermined form. The image is characterized by further including a step of selecting from the captured images of the plurality of droplets captured by the imaging unit.

According to the present invention, even when a foreign substance is present in the droplet formed on the ejected body by the functional liquid discharged for inspection or the ejected body is scratched, the functional droplet is Based on the inspection result of the discharge state of the functional liquid using the imaging result, the discharge condition of the functional liquid can be appropriately corrected.

It is a schematic diagram which shows the outline of the structure of the inspection apparatus which concerns on this embodiment. It is a flowchart explaining an example of the inspection method which concerns on this Embodiment. It is a schematic side view which shows the outline of the structure of the functional liquid discharge device provided with the inspection device which concerns on this embodiment. It is a schematic plan view of the functional liquid discharge device of FIG. It is a schematic diagram which shows the outline of the structure of the inspection apparatus which concerns on a reference embodiment. It is a flowchart explaining an example of the inspection method which concerns on a reference embodiment. It is a figure which shows the example of the droplet formed by the functional liquid. It is a figure explaining the technical effect of the inspection apparatus of a reference embodiment. It is a figure which shows the example of the captured image of the droplet formed by the functional liquid which was inspected and discharged. It is a figure which shows another example of the captured image of the droplet formed by the functional liquid which was inspected and discharged.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present specification and the drawings, elements having substantially the same functional configuration are designated by the same reference numerals, so that duplicate description will be omitted.

First, the configuration of the inspection device according to the present embodiment will be described with reference to FIG. FIG. 1 is a schematic view showing an outline of the configuration of an inspection device. It should be noted that the dimensions of each component do not necessarily correspond to the actual dimensions in order to prioritize the ease of understanding the technology.

The inspection device 1 of FIG. 1 has an imaging unit 10 and a control unit 11. The inspection device 1 takes an image of a plurality of inspection droplets 21 formed on the inspection sheet 20 by the imaging unit 10 and inspects the discharge state of the functional liquid forming the droplets 21. Each droplet 21 is formed by ejecting the functional liquid from the nozzle twice or more a predetermined number of times by an inkjet method. Further, the number of droplets 21 formed on the inspection sheet 20 is, for example, several tens. The inspection sheet 20 is an example of the “discharged body” according to the present embodiment.

The imaging unit 10 is arranged in a direction in which the optical axis of the imaging unit 10 is perpendicular to the main surface of the inspection sheet 20, and is arranged vertically above the inspection sheet 20 in the present embodiment. Various cameras can be used for the image pickup unit 10, and for example, an area scan camera is used. Then, the imaging unit 10 images the region where the droplet 21 of the inspection sheet 20 is formed. The captured image captured by the imaging unit 10 is output to the control unit 11. It is preferable that the inspection device 1 or the stage on which the inspection sheet 20 is placed is movable so that the captured images of all the droplets 21 on the inspection sheet 20 can be captured.

For example, an LED light source, a halogen light source, or an ultraviolet light source is used as the light source for observing the droplets, and the form of the light source is a surface light source of coaxial epi-illumination or transmitted light, and the solvent in the droplets is impregnated into the inspection sheet during observation. Alternatively, the droplets can be observed more clearly by setting the solvent in the droplets to be in a vaporized state.

The control unit 11 controls the operation of the imaging unit 10 and the like in the inspection device 1. Further, the control unit 11 has a measurement unit 11a and a selection unit 11b.

The measuring unit 11a measures the formation state of the droplet 21 based on the imaging result of the imaging unit 10. For example, the measuring unit 11a measures the size and formation position of the selected droplet 21.

The selection unit 11b selects the droplet 21 to be measured by the measurement unit 11a from among the plurality of droplets 21. Specifically, the selection unit 11b performs pattern matching between the entire image of the droplet 21 (captured image) captured by the imaging unit 10 and the entire image of the droplet having a predetermined shape for each of the plurality of droplets 21. Is performed, and the droplet 21 to be measured by the measuring unit 11a is selected from the plurality of droplets 21 based on the matching result.

The image of the droplet having the predetermined morphology is an image of a perfect circle on a black background (white background in the figure) when the morphology of the normal functional droplet is a perfect circle on a black background (see FIG. 9A). When the morphology of the normal functional droplet is a concentric double circle on a white background (see FIG. 10 (A)), it is an image of a concentric double circle on a white background. The "form" includes at least a shape and a color. The image of the droplet having the predetermined form is, for example, stored in advance in the inspection device 1.

Further, in the pattern matching, for example, as an image of the droplet 21 and an image of the droplet having the above-mentioned predetermined form, a grayscale image represented by 256 gradations is acquired, and the matching degree is calculated for each pixel. Will be done. For example, when the average value of the calculated matching degrees exceeds a predetermined value, the selection unit 11b selects the droplet 21 related to the image as the measurement target.
Instead of the grayscale image represented by 256 gradations, a color image in which each color is represented by 256 gradations may be used.

Further, as a pattern matching method, a known method can be arbitrarily adopted. For example, Koji Ikeda and 4 others, "High-speed template matching by monotonic function of normalization correlation calculation", IEICE Transactions D, IEICE, September 25, 2009, J83-D2, 9th No., p. The method described in 1861-1869 can be adopted.

Although the image having a predetermined form (hereinafter referred to as a reference image) is assumed to be stored in advance in the above description, it may be selected from the captured images of a plurality of droplets 21. When selecting, for example, the operator manually selects it. Further, a reference image selection unit 11c may be provided in the control unit 11 to perform pattern matching different from the above and automatically select the captured image closest to the perfect circle or the double concentric circles.
The reference image selection unit 11c may change the reference image as follows. That is, the reference image selection unit 11c is based on the reference image manually selected by the operator or the reference image automatically selected by the reference image selection unit 11c, and all the liquids are similar to the pattern matching described above. For the captured image of the drop 21, pattern matching is performed on the entire image, and the distribution of the degree of matching is acquired. Then, the reference image selection unit 11c automatically extracts one image from the captured images showing the peak matching degree when there is no peak at the highest matching point in the matching degree distribution. The image may be used as a new reference image. Specifically, assuming that the highest point of the matching degree is 1000, and there is a peak in the matching degree distribution where the matching degree is 900, one image is selected from the captured images having the matching degree of 900. The image may be extracted and used as a new reference image.

The control unit 11 is, for example, a computer and has a program storage unit (not shown). In the program storage unit, in addition to a program for controlling the operation of the imaging unit 10, a program for image processing the captured image and the size of the droplet 21 and the droplet based on the image-processed data. A program for calculating the position of the 21 on the inspection sheet 20 is stored. Further, the program storage unit also stores a program that performs pattern matching in the selection unit 11b and the reference image selection unit 11c based on the image-processed data. The program is recorded on a computer-readable storage medium such as a computer-readable hard disk (HD), flexible disk (FD), compact disk (CD), magnet optical desk (MO), or memory card. It may have been installed in the control unit 11 from the storage medium.

Next, a method of inspecting the discharge state of the functional liquid, which is performed using the inspection device 1 configured as described above, will be described with reference to FIGS. 9 and 10 with reference to FIG. FIG. 2 is a flowchart illustrating an example of the above inspection method.

When the functional liquid is discharged from the nozzle for inspection and a plurality of droplets 21 are formed on the inspection sheet 20, the imaging unit 10 images the droplets 21 on the inspection sheet 20 (step S1). The imaging by the imaging unit 10 is performed until the imaging of all the droplets 21 on the inspection sheet 20 is completed. The captured image captured by the imaging unit 10 is output to the measurement unit 11a and the selection unit 11b of the control unit 11.

When the plurality of droplets 21 imaged by the imaging unit 10 do not contain the foreign matter C1 as shown in FIG. 9, the inspection sheet 20 is not scratched, and the captured image of the droplet 21 is acquired. Ideally, the captured images L1 and L2 are perfect circles or concentric double circles, as shown in FIGS. 9 (A) and 10 (A). However, the acquired captured image L1 may not be a perfect circle as shown in FIGS. 9 (B) and 9 (C), or may contain a foreign substance C1 as shown in FIGS. 9 (C) and 9 (D). In some cases, the acquired image L2 may not be a double concentric circle as shown in FIGS. 10 (B) and 10 (C).

Therefore, the selection unit 11b performs pattern matching on the entire image using the reference image for each of the captured images of the plurality of droplets 21, and based on the matching result, the liquid to be measured from among the plurality of droplets 21. Drop 21 is selected (step S2). For example, the selection unit 11b determines whether or not the droplet 21 corresponding to each captured image is to be measured based on the pattern matching result, and the droplet corresponding to the captured image whose matching degree exceeds the threshold value. 21 is selected as the measurement target. Thereby, only the droplet 21 corresponding to the captured images L1 and L2 similar to the captured images L1 and L2 of FIGS. 9 (A) and 10 (A) can be selected / extracted as the measurement target.

The measuring unit 11a calculates / measures the size and formation position of the droplet 21, that is, the discharge amount of the functional liquid and the discharge bending of the captured image, that is, the droplet 21 selected by the selection unit 11b, based on the captured image. (Step S3).
In the functional liquid discharge device including the inspection device 1, the discharge conditions are adjusted / corrected based on the measurement results of the size and formation position of the droplet 21 selected by the selection unit 11b. As a result, even when foreign matter is present in the droplets formed on the ejected body by the functional liquid ejected for inspection or there are scratches on the ejected body, the functional liquid is appropriately discharged. be able to.

In addition, a plurality of nozzles are usually provided for one functional liquid discharge head. Therefore, when inspecting the discharge state of the functional liquid from the nozzles, the functional liquid is discharged from each of the plurality of nozzles, a plurality of droplets are formed for each nozzle, and the measurement is performed from the plurality of droplets by the above method. The target droplet may be selected for each nozzle. Further, at this time, the reference image used for pattern matching may be different for each nozzle or may be common to all nozzles.
Further, the inspection method in the inspection apparatus 1 can be applied regardless of whether the inspection sheet is liable or sparse.

Next, an application example of the inspection device 1 configured as described above will be described with reference to FIGS. 3 and 4. FIG. 3 is a schematic side view showing an outline of the configuration of the functional liquid discharge device including the inspection device 1. FIG. 4 is a schematic plan view of the functional liquid discharge device of FIG. In the following, the main scanning direction of the substrate (hereinafter sometimes referred to as a work) is the X-axis direction, and the sub-scanning direction orthogonal to the main scanning direction is orthogonal to the Y-axis direction, the X-axis direction, and the Y-axis direction. The vertical direction is the Z-axis direction, and the rotation direction around the Z-axis direction is the θ direction.

The functional liquid discharge device 100 of FIGS. 3 and 4 is coated with an organic material for forming any of the organic EL layers of the organic light emitting diode (for example, a hole injection layer, a hole transport layer, and a light emitting layer). The organic material of the present embodiment is a solution in which a predetermined material for forming each layer of the organic EL layer is dissolved in an organic solvent.

The functional liquid discharge device 100 extends in the main scanning direction (X-axis direction) and is straddled over the X-axis table 30 for moving the work W in the main scanning direction and the X-axis table 30 for sub-scanning. It has a pair of Y-axis tables 31 and 31 extending in the direction (Y-axis direction). A pair of X-axis guide rails 32, 32 are provided extending in the X-axis direction on the upper surface of the X-axis table 30, and an X-axis linear motor (not shown) is provided on each X-axis guide rail 32. ing. A Y-axis guide rail 33 is provided on the upper surface of each Y-axis table 31 so as to extend in the Y-axis direction, and a Y-axis linear motor (not shown) is provided on the Y-axis guide rail 33.

A carriage unit 40 and an imaging unit 50 are provided on the pair of Y-axis tables 31, 31. A work stage 60 and a discharge inspection unit 70 are provided on the X-axis table 30.

A plurality of carriage units 40, for example, 10 are provided in the Y-axis table 31. Each carriage unit 40 has a carriage plate 41, a carriage rotation mechanism 42, a carriage 43, and a functional liquid discharge head 44.

The carriage plate 41 is attached to the Y-axis guide rail 33, and is movable in the Y-axis direction by a Y-axis linear motor provided on the Y-axis guide rail 33.

A carriage rotation mechanism 42 is provided in the center of the lower surface of the carriage plate 41, and the carriage 43 is detachably attached to the lower end of the carriage rotation mechanism 42. The carriage 43 is rotatable in the θ direction by the carriage rotation mechanism 42.

A plurality of functional liquid discharge heads 44 are provided on the lower surface of the carriage 43. In the present embodiment, for example, three functional liquid discharge heads 44 are provided in the X-axis direction and two in the Y-axis direction, that is, a total of six functional liquid discharge heads 44 are provided. A plurality of discharge nozzles (not shown) are formed on the lower surface of the functional liquid discharge head 44, that is, the nozzle surface, and droplets of the functional liquid are discharged from the discharge nozzles.

The image pickup unit 50 has an image pickup unit 10.
The imaging unit 10 images the droplets that have been inspected and ejected on the inspection sheet 20 of the ejection inspection unit 70. The imaging unit 10 is supported by a base 51 provided on the side surface of the Y-axis table 31 on the positive direction side of the X-axis among the pair of Y-axis tables 31 and 31, and all of them are inspected and discharged to the inspection sheet 20. It is configured to be able to image droplets.

The work stage 60 is, for example, a vacuum suction stage, in which the work W is sucked and placed. The work stage 60 is rotatably supported in the θ direction by a stage rotation mechanism 61 provided on the lower surface side of the work stage 60.

The work stage 60 and the stage rotation mechanism 61 are supported by a first X-axis slider 62 provided on the lower surface side of the stage rotation mechanism 61. The first X-axis slider 62 is attached to the X-axis guide rail 32 and is movable in the X-axis direction by an X-axis linear motor provided on the X-axis guide rail 32. The work stage 60 (work W) is also movable in the X-axis direction along the X-axis guide rail 32 by the first X-axis slider 62.

The discharge inspection unit 70 is a unit that receives inspection discharge from the functional liquid discharge head 44. The above-mentioned inspection sheet 20 is arranged in the discharge inspection unit 70.
The discharge inspection unit 70 is mounted on the second X-axis slider 80. The second X-axis slider 80 is attached to the X-axis guide rail 32 and is movable in the X-axis direction by an X-axis linear motor provided on the X-axis guide rail 32. The discharge inspection unit 70 is also movable in the X-axis direction along the X-axis guide rail 32 by the second X-axis slider 80.

The above-mentioned control unit 11 is provided in the functional liquid discharge device 100. Therefore, the inspection device 1 provided inside the functional liquid discharge device 100 is controlled by the control unit 11. However, in the program storage unit (not shown) of the control unit 11, in addition to the program for controlling the inspection device 1, a program for controlling the processing of the substrate in the functional liquid discharge device 100 is also stored. Therefore, the control unit 11 also adjusts / controls the discharge conditions from the nozzle of the functional liquid discharge head 44.

The control unit 11 also has a data storage unit (not shown). In the data storage unit, for example, normal data of the size and position of the droplet formed by the functional liquid discharge device 100, that is, drawing data (bitmap data) matching the desired size and position is stored in advance. .. The use of this drawing data will be described later.

Next, the work processing performed by using the functional liquid discharge device 100 configured as described above will be described. In the following description, on the X-axis table 30, the area on the negative direction side of the X-axis from the Y-axis table 31 is referred to as the carry-in / out area A1, and the area between the pair of Y-axis tables 31 and 31 is referred to as the processing area A2. The area on the positive direction side of the X-axis from the Y-axis table 31 is called the standby area A3.

First, the work stage 60 is arranged in the carry-in / out area A1, and the work W carried into the functional liquid discharge device 100 by the transport mechanism (not shown) is placed on the work stage 60. Subsequently, the work stage 60 is moved from the loading / unloading area A1 to the processing area A2 by the X-axis slider 62. In the processing area A2, droplets are discharged from the functional liquid discharge head 44 to the work W that has moved below the functional liquid discharge head 44. Further, the work stage 60 is further moved to the standby area A3 side so that the entire surface of the work W passes below the functional liquid discharge head 44. Then, the work W is reciprocated in the X-axis direction, and the carriage unit 40 is appropriately moved in the Y-axis direction to draw a predetermined pattern on the work W.

After drawing, the work stage 60 is moved to the loading / unloading area A1.
When the work stage 60 moves to the carry-in / out area A1, the work W for which the drawing process has been completed is carried out from the functional liquid discharge device 100. Subsequently, the next work W is carried into the functional liquid discharge device 100.

While the work W is being carried in and out, or before being carried out, the inspection device 1 inspects the discharge state of the functional liquid discharged from the functional liquid discharge head 44. Specifically, first, the discharge inspection unit 70 is moved from the standby area A3 to the processing area A2 by the second X-axis slider 80. In the processing area A2, the inspection sheet 20 of the discharge inspection unit 70 is arranged below the functional liquid discharge head 44, and the functional liquid is inspected and discharged a predetermined number of times (multiple times) from the nozzle head 54 with respect to the surface of the inspection sheet 20. Drop 21 is formed (step S3). As described above, the functional liquid discharge head 44 is provided with a plurality of nozzles, and a plurality of droplets 21 are formed for each nozzle.

After that, the discharge inspection unit 70 is moved to the positive direction side of the X-axis, and the inspection sheet 20 of the discharge inspection unit 70 is arranged below the imaging unit 10. Then, the plurality of droplets 21 are imaged by the imaging unit 10. The captured image is output to the selection unit 11b and the measurement unit 11a of the control unit 11.

In the selection unit 11b, pattern matching is performed on the entire image using the reference image for the captured images of the plurality of droplets 21 formed by the nozzles for each nozzle. Then, the selection unit 11b selects the droplet 21 to be measured by the measurement unit 11a from the plurality of droplets 21 based on the matching result.

With respect to the selected droplet 21, the measuring unit 11a measures the size of the droplet 21 and the position of the droplet 21 on the inspection sheet 20 based on the captured image of the droplet. In this way, the discharge state of the functional liquid from each nozzle is inspected based on the formation state of the droplet 21. Normally, the selection unit 11b selects two or more droplets 21 from the plurality of droplets 21.

When the measurement unit 11a measures the size and position of two or more droplets 21 for each nozzle, the control unit 11 subsequently calculates the average value of the size and position of the droplet 21 for each nozzle. Then, the control unit 11 compares the measurement data of the average size and the average position of the droplet 21 with the normal data of the size and position of the droplet stored in advance for each nozzle. Then, when the measurement data deviates from the normal data, the control unit 11 sets the discharge condition of the functional liquid so that the functional liquid discharge head 44 of the functional liquid discharge device 100 discharges the functional liquid in a normal form. adjust. The inspection of the discharge state of the functional liquid and the adjustment of the discharge condition of the functional liquid may be performed for each one substrate W or for each predetermined number of substrates W.

According to the above embodiment, since the inspection device 1 is provided inside the functional liquid discharge device 100, the discharge state of the functional liquid discharged from the nozzle of the functional liquid discharge head 44 of the functional liquid discharge device 100 can be checked. It can be inspected and the discharge conditions of the functional liquid can be adjusted by feedback control. Therefore, it is possible to suppress the discharge failure of the functional liquid in the functional liquid discharge device 100, appropriately control the size of the functional liquid (that is, the weight of the functional liquid) and the position of the functional liquid discharged to the substrate W, and control the substrate W. The organic material can be appropriately applied to the surface.

In the functional liquid discharge device 100, the inspection device 1 inspects the discharge state of the functional liquid and adjusts the discharge conditions of the functional liquid, although in the above example, the coating process was performed after the coating process on the substrate W was completed. You may go ahead.
Further, the layout of the functional liquid discharge device 100 according to the above embodiment is not limited to the layout shown in FIGS. 3 and 4, and can be arbitrarily set.

Further, as an application example of the inspection device 1, the functional liquid discharge device 100 for forming the organic EL layer of the organic light emitting diode has been described, but the application example of the inspection device 1 is not limited to this. For example, the inspection device 1 may be applied to a substrate processing device or the like to which a color resist is applied.

(Reference embodiment)
First, the configuration of the inspection device according to the reference embodiment will be described with reference to FIG. FIG. 5 is a schematic view showing an outline of the configuration of the inspection device. It should be noted that the dimensions of each component do not necessarily correspond to the actual dimensions in order to prioritize the ease of understanding the technology.

The inspection device 1'in FIG. 5 has an imaging unit 10 and a control unit 11'. The inspection device 1'images a plurality of inspection droplets 21 formed on the inspection sheet 20 by the imaging unit 10 and inspects the discharge state of the functional liquid forming the droplets 21. Each droplet 21 is formed by ejecting the functional liquid from the nozzle twice or more a predetermined number of times by an inkjet method. Further, the number of droplets 21 formed on the inspection sheet 20 is, for example, several tens.

The imaging unit 10 is arranged in a direction in which the optical axis of the imaging unit 10 is perpendicular to the main surface of the inspection sheet 20, and is arranged vertically above the inspection sheet 20 in the present embodiment. Various cameras can be used for the image pickup unit 10, and for example, an area scan camera is used. Then, the imaging unit 10 images the region where the droplet 21 of the inspection sheet 20 is formed. The captured image captured by the imaging unit 10 is output to the control unit 11'. It is preferable that the inspection device 1'or the stage on which the inspection sheet 20 is placed is movable so that the captured images of all the droplets 21 on the inspection sheet 20 can be captured.

For example, an LED light source, a halogen light source, or an ultraviolet light source is used as the light source for observing the droplets, and the form of the light source is a surface light source of coaxial epi-illumination or transmitted light, and the solvent in the droplets is impregnated into the inspection sheet during observation. Alternatively, the droplets can be observed more clearly by setting the solvent in the droplets to be in a vaporized state.

The control unit 11'controls the operation of the imaging unit 10 and the like in the inspection device 1'. Further, the control unit 11'has a measurement unit 11a and a selection unit 11b'.

The measuring unit 11a measures the formation state of the droplet 21 based on the imaging result of the imaging unit 10. For example, the measuring unit 11a measures the size and formation position of the selected droplet 21.

The selection unit 11b'selects the droplet 21 to be measured by the measurement unit 11a from the plurality of droplets 21, and uses the imaging result of the imaging unit 10 to select the droplet 21 to be measured. The selection is made based on the formation state of the droplet 21. For example, the selection unit 11b'selects the droplet 21 to be measured based on the shape of the droplet 21. More specifically, the selection unit 11b'performs pattern matching based on a predetermined image on the images captured by the imaging unit 10 of each of the plurality of droplets 21, and the droplets 21 to be measured based on the matching result. Select. The predetermined image is an image of droplets having a predetermined appropriate shape (for example, a perfect circle), and the predetermined image may be stored in advance in the inspection device 1, or a plurality of liquids. You may select from the captured image of the drop 21. When selecting, for example, the operator may manually select the image, or pattern matching different from the above may be performed to automatically select the captured image closest to the perfect circle.

As a pattern matching method, a known method can be arbitrarily adopted.

The control unit 11'is, for example, a computer, and has a program storage unit (not shown). In the program storage unit, in addition to a program for controlling the operation of the imaging unit 10, a program for image processing the captured image and the size of the droplet 21 and the droplet based on the image-processed data. A program for calculating the position of the 21 on the inspection sheet 20 is stored. Further, the program storage unit also stores a program that performs pattern matching in the selection unit 11b'based on the image-processed data. The program is recorded on a computer-readable storage medium such as a computer-readable hard disk (HD), flexible disk (FD), compact disk (CD), magnet optical desk (MO), or memory card. It may have been installed in the control unit 11'from the storage medium.

Next, a method of inspecting the discharge state of the functional liquid, which is performed using the inspection device 1'configured as described above, will be described with reference to FIGS. 6 and 7. FIG. 6 is a flowchart illustrating an example of the above inspection method. FIG. 7 is a diagram showing an example of droplets formed by the functional liquid.

When the functional liquid is discharged from the nozzle for inspection and a plurality of droplets 21 are formed on the inspection sheet 20, the imaging unit 10 images the droplets 21 on the inspection sheet 20 (step S1). The imaging by the imaging unit 10 is performed until the imaging of all the droplets 21 on the inspection sheet 20 is completed. The captured image captured by the imaging unit 10 is output to the measurement unit 11a and the selection unit 11b'of the control unit 11'.

Ideally, the plurality of droplets 21 imaged by the imaging unit 10 are all circular in a plan view as in the droplet 21 of FIG. 7A. However, the plurality of droplets 21 have a shape such that a notch is provided on the outer circumference of the circle in a plan view as in the droplet 21 of FIG. 7 (B), and / or FIG. 7 (C). ), Which has a shape such that an ear portion is provided on the outer circumference of a circle in a plan view is also included.

Therefore, the selection unit 11b'performs pattern matching related to the shape of the droplet 21 based on a predetermined image stored in advance in the inspection device 1'for the captured image of each of the plurality of droplets 21, and sets the measurement target. The droplet 21 is selected (step S12). For example, the selection unit 11b'determines whether or not the droplet 21 corresponding to each captured image is to be measured based on the pattern matching result related to the shape of the droplet 21, and the matching degree exceeds the threshold value. The droplet 21 corresponding to the captured image is selected as the measurement target. As a result, only the droplet 21 having a shape similar to that of the droplet 21 shown in FIG. 7A can be selected / extracted as a measurement target.

The measuring unit 11a calculates the size and formation position of the droplet 21, that is, the discharge amount of the functional liquid and the discharge bend of the captured image, that is, the droplet 21 selected by the selection unit 11b', based on the captured image. Measure (step S3).
In the functional liquid discharge device including the inspection device 1', the discharge conditions are adjusted / corrected based on the measurement results of the size and formation position of the droplet 21 selected by the selection unit 11b'. As a result, the functional liquid can be appropriately discharged.

FIG. 8 is a diagram for explaining the effect of the inspection device 1', and each diagram shows the distribution of the droplet 21, where the horizontal axis is the area and the vertical axis is the frequency.
As a method of extracting the droplet 21 having a shape close to FIG. 7 (A) from the plurality of droplets 21, in addition to the method of extracting based on the shape of the droplets 21 as described above, the following area A method of extracting based on is conceivable.

The droplet 21 having the shape shown in FIG. 7 (B) has a smaller area than the droplet 21 having the shape shown in FIG. 7 (A), and has the shape shown in FIG. 7 (C). The area of the droplet 21 is larger than that of the droplet 21 having the shape shown in FIG. 7 (A). Therefore, as a method of extracting the droplet 21 having a shape close to that of FIG. 7A, a method of extracting based on the area of the droplet 21, more specifically, the droplet 21 having an area larger than a predetermined value and another method. A method of excluding the droplet 21 having an area smaller than the predetermined value of is excluded from the measurement target can be considered.

The distribution P100 of the droplet 21 including all the droplet 21 of the shape of FIG. 7 (A), the droplet 21 of the shape of FIG. 7 (B), and the droplet 21 of the shape of FIG. 7 (C) is shown in FIG. 8 (A). ), Even if the measurement target is selected based on the above area, the droplet 21 having the shapes of FIGS. 7 (B) and 7 (C) can be measured. It seems possible to exclude from.

However, in reality, the distribution of the droplet 21 including all the droplet 21 in the shape of FIG. 7 (A), the droplet 21 in the shape of FIG. 7 (B), and the droplet 21 in the shape of FIG. 7 (C) (hereinafter, Overall distribution) P1 is not a normal distribution as shown in FIG. 8 (B). The distribution P11 of the droplet 21 in the shape of FIG. 7 (A), the area distribution P13 of the droplet 21 in the shape of FIG. 7 (B), and the distribution P12 of the droplet 21 in the shape of FIG. 7 (C) are normal distributions. The overall distribution P1 is a superposition of the distributions showing these normal distributions.

Therefore, even if exclusion is performed based on the area, it is impossible to completely exclude the droplet 21 having the shape shown in FIG. 7 (B) and the droplet 21 having the shape shown in FIG. 7 (C). Is.

On the other hand, as in the inspection method according to the present embodiment, by extracting based on the shape of the droplet 21, only the droplet 21 showing the distribution P11 in FIG. 8 (B), that is, the shape in FIG. 7 (A). Only the droplet 21 having the above can be extracted.

Therefore, in the inspection method according to the present embodiment, the formation state can be measured only for the droplet 21 having the shape shown in FIG. 7A, and therefore, the discharge condition of the functional liquid is appropriately corrected based on the measurement result. Can be made to.

In addition, a plurality of nozzles are usually provided for one functional liquid discharge head. Therefore, when inspecting the discharge state of the functional liquid from the nozzles, the functional liquid is discharged from each of the plurality of nozzles, a plurality of droplets are formed for each nozzle, and the liquid is selected from the plurality of droplets for each nozzle. The droplet to be measured may be selected based on the shape of the droplet. Further, at this time, the predetermined image used for pattern matching may be different for each nozzle, or may be common to all nozzles.

The method of determining the droplet 21 to be measured among the plurality of droplets 21 based on the size of the droplets is when the entire distribution of the droplets 21 shows a normal distribution (for example, FIG. It is useful when only the droplet 21 having the shape as shown in 7 (A) is formed).

Although the embodiments of the present invention have been described above, the present invention is not limited to such examples. It is clear that a person skilled in the art can come up with various modifications or modifications within the scope of the technical idea described in the claims, and of course, the technical scope of the present invention also includes them. It is understood that it belongs to.

1 ... Inspection device 10 ... Imaging unit 11a ... Measurement unit 11b ... Measurement unit 11c ... Reference image selection unit 11 ... Control unit 20 ... Inspection sheet 21 ... Droplet 44 ... Functional liquid discharge head 100 ... Functional liquid discharge device

Claims (8)

An inspection device that inspects the discharge state of functional liquid from a nozzle.
An imaging unit that captures a plurality of droplets formed on the ejected body by the functional liquid discharged from the nozzle, and an imaging unit.
A measuring unit that measures the formation state of the droplet based on the imaging result of the imaging unit, and a measuring unit.
For each of the plurality of droplets, pattern matching is performed between the entire image captured by the imaging unit and the entire image of the droplet having a predetermined shape, and the measurement of the plurality of droplets is performed based on the matching result. A selection unit that selects the droplet to be measured in the unit, and a selection unit
An inspection apparatus comprising: a reference image selection unit for selecting an image of a droplet having a predetermined form from the captured images of the plurality of droplets imaged by the imaging unit. The inspection apparatus according to claim 1, wherein the captured image and the image of a droplet having a predetermined form are grayscale images represented by 256 gradations. The inspection apparatus according to claim 1, wherein the captured image and the image of a droplet having a predetermined form are color images in which each color is represented by 256 gradations. With multiple nozzles
The inspection device according to any one of claims 1 to 3 and
Each nozzle is provided with a control unit that corrects the discharge condition of the functional liquid based on the measurement result of the measurement unit for the droplet selected as the droplet to be measured by the measurement unit. A functional liquid discharge device characterized by. It is an inspection method that inspects the discharge state of the functional liquid from the nozzle.
A step of capturing a plurality of droplets formed on the ejected body by the functional liquid discharged from the nozzle by the imaging unit, and
For each of the plurality of droplets, pattern matching is performed between the entire image captured by the imaging unit and the entire image of the droplet having a predetermined shape, and based on the matching result, the measurement target of the plurality of droplets. Steps to select droplets and
For droplets of a selected measurement object, based on the result of imaging by the imaging unit, viewed including the steps of measuring the formation state of the droplet, and
Inspection method wherein an image of a droplet having a predetermined form, characterized by further including Mukoto the step of selecting from among the captured images of the plurality of droplets captured by the imaging unit. The inspection method according to claim 5, wherein the captured image and the image of the droplet having the predetermined form are grayscale images represented by 256 gradations. The inspection method according to claim 5, wherein the captured image and the image of the droplet having the predetermined form are color images in which each color is represented by 256 gradations. It is a method of correcting the discharge condition of the functional liquid from the nozzle.
A step of capturing a plurality of droplets formed on the ejected body by the functional liquid discharged from the nozzle by the imaging unit, and
For each of the plurality of droplets, pattern matching is performed between the entire image captured by the imaging unit and the entire image of the droplet having a predetermined shape, and based on the matching result, the measurement target of the plurality of droplets. Steps to select droplets and
With respect to the selected droplet to be measured, a step of measuring the formation state of the droplet based on the imaging result of the imaging unit, and
For each nozzle, the step of correcting the discharge condition of the functional liquid based on the measurement result in the measurement step for the selected droplet to be measured is included.
A correction method further comprising a step of selecting an image of a droplet having a predetermined form from the captured images of the plurality of droplets imaged by the imaging unit.

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