JP2016185502A - Droplet discharge head inspection equipment, droplet discharge head inspection method and droplet discharge device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide droplet discharge head inspection equipment capable of obtaining an organic EL element having a long lifetime.SOLUTION: Droplet discharge head inspection equipment includes a luminaire 32 for emitting light having a wavelength region higher than a red wavelength region toward a droplet discharge surface 26a of a droplet discharge head 26 for discharging a functional fluid therefrom, and an imaging device 31 for imaging the droplet discharge surface 26a irradiated with the light from the luminaire 32.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a droplet discharge head inspection device, a droplet discharge head inspection method, and a droplet discharge device.

  2. Description of the Related Art Conventionally, an organic layer of an organic electroluminescence (hereinafter abbreviated as EL) element is formed using a droplet discharge method such as an inkjet method. However, the ink jet apparatus includes a large number of nozzles for discharging droplets, and nozzle discharge defects may occur. As a method for detecting a discharge failure of a nozzle, the following Patent Document 1 irradiates inspection light into a cavity of a droplet discharge head in which a functional liquid is accommodated, and determines the functional liquid based on the intensity of the reflected inspection light. A method for determining the state has been proposed.

JP 2012-96170 A

However, when an organic EL element is manufactured using the droplet discharge device after inspecting a nozzle for defective discharge by the method described in Patent Document 1, there is a problem that it is difficult to obtain a long-life organic EL element. there were.
As described above, the organic EL element has been described as an example, but other electronic devices have the same problem.

  One aspect of the present invention has been made to solve the above problems, and is a droplet discharge head inspection device used in a droplet discharge device for forming an electronic device including an organic EL element, and has a long life. Another object of the present invention is to provide a liquid droplet ejection head inspection apparatus from which the electronic device can be obtained. Another aspect of the present invention is a droplet discharge head inspection method used in a droplet discharge apparatus for forming an electronic device, and provides a droplet discharge head inspection method capable of obtaining a long-life electronic device. One of the purposes. Another object of one aspect of the present invention is to provide a droplet discharge apparatus that is used for forming an electronic device and that can provide a long-life electronic device.

  In order to achieve the above object, a droplet discharge head inspection apparatus according to one aspect of the present invention is an illumination that emits light in a red wavelength region toward a droplet discharge surface of a droplet discharge head that discharges a functional liquid. And an image pickup device that picks up an image of the droplet discharge surface irradiated with light from the illumination device.

  The droplet discharge head inspection apparatus according to one aspect of the present invention can emit light in the red wavelength region, which has lower energy than light in the short wavelength region such as the blue wavelength region, from the illumination device. As a result, even when light is applied to the droplet discharge surface during the inspection of the droplet discharge head, the deterioration of the functional liquid is unlikely to proceed. Thereby, a long-life electronic device can be obtained.

In the liquid droplet ejection head inspection apparatus according to one aspect of the present invention, the wavelength region included in the light emitted from the illumination device may be 600 nm or more.
According to this configuration, deterioration of the functional liquid can be suppressed.

  A droplet discharge head inspection device according to one aspect of the present invention includes an illumination device that emits light including at least a red wavelength region toward a droplet discharge surface of a droplet discharge head that discharges a functional liquid. An image pickup device that picks up an image of the droplet discharge surface irradiated with light from the illumination device, and is arranged between the illumination device and the image pickup device, and shields light in a wavelength range shorter than the red wavelength range. And a filter to be provided.

  In the liquid droplet ejection head inspection apparatus according to one aspect of the present invention, light including at least a wavelength region greater than or equal to the red wavelength region is emitted from the illumination device, and light in a wavelength region shorter than the red wavelength region is blocked by the filter. . As a result, for example, light in the red wavelength range, which has lower energy than light in the short wavelength range such as the blue wavelength range, can be emitted from the illumination device. As a result, even when light is applied to the droplet discharge surface during the inspection of the droplet discharge head, the deterioration of the functional liquid is unlikely to proceed. Thereby, a long-life electronic device can be obtained. Moreover, the wavelength range of the light irradiated to a droplet discharge head can be adjusted by replacing | exchanging a filter.

In the liquid droplet ejection head inspection apparatus according to one aspect of the present invention, the filter that transmits light in the red wavelength region transmits light having a wavelength region of 600 nm or more and shields light having a wavelength region of less than 600 nm. There may be.
According to this configuration, deterioration of the functional liquid can be suppressed.

In the liquid droplet ejection head inspection apparatus according to one aspect of the present invention, the illumination device can switch between emission of light in the red wavelength region and emission of light in a wavelength region other than the red wavelength region. May be.
According to this configuration, for example, when using a functional liquid that does not cause deterioration, the illumination device can be switched to emit light in a wavelength region other than the red wavelength region. Thereby, the test | inspection according to the functional liquid to be used can be performed.

In the liquid droplet ejection head inspection apparatus according to one aspect of the present invention, the functional liquid may be a functional liquid used for forming an organic layer of an organic electroluminescence element.
According to this configuration, a long-life organic EL element can be obtained.

A droplet discharge apparatus according to one aspect of the present invention includes the droplet discharge head and the droplet discharge head inspection apparatus according to one aspect of the present invention.
According to this configuration, since the droplet discharge device includes the droplet discharge head inspection device according to one aspect of the present invention, it is possible to manufacture a long-life electronic device.

  According to one aspect of the present invention, a droplet discharge head inspection method irradiates light in a red wavelength region toward a droplet discharge surface of a droplet discharge head that discharges a functional liquid for forming an electronic device. Further, the liquid droplet ejection surface is observed.

  In the droplet discharge head inspection method according to one aspect of the present invention, light in a red wavelength region, which has lower energy than light near a short wavelength such as a blue wavelength region, is irradiated from an illumination device. As a result, even when light is applied to the droplet discharge surface during the inspection of the droplet discharge head, the deterioration of the organic layer forming functional liquid is unlikely to proceed. Thereby, a long-life electronic device can be obtained.

It is a schematic block diagram which shows the droplet discharge apparatus of 1st Embodiment. It is a schematic block diagram which shows the test | inspection unit of 1st Embodiment. It is a figure which shows the wavelength range of the light used as inspection light. It is a schematic block diagram which shows the test | inspection unit of 2nd Embodiment.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a schematic configuration diagram showing a droplet discharge device of this embodiment.
FIG. 2 is a schematic configuration diagram showing the droplet discharge head inspection apparatus of the present embodiment.
In the following drawings, in order to make each component easy to see, the scale of the size may be varied depending on the component.

First, the configuration of the droplet discharge device will be described.
As shown in FIG. 1, a droplet discharge device 1 according to the present embodiment includes a droplet discharge head 2 having a nozzle hole communicating with a cavity that stores a functional liquid, and a state of a droplet discharge surface of the droplet discharge head 2. And a maintenance unit 4 for performing maintenance of the droplet discharge head 2. In the present embodiment, the transport device 5 that transports the sheet-like workpiece W is provided, and the functional liquid is ejected as droplets by an inkjet method onto the transported workpiece W, and an organic layer of an organic EL element is used as an example of an electronic device. A droplet discharge device to be formed will be described as an example.
The inspection unit 3 of the present embodiment corresponds to the droplet discharge head inspection device in the claims.

  The transport device 5 is a roll-to-roll transport device. The conveyance device 5 includes a supply roller 11, a material removal roller 12, and conveyance rollers 13a to 13f. The feed roller 11 is a roller around which a sheet-like workpiece W is wound, and supplies the workpiece W. The material removal roller 12 takes up the drawn work W and removes the material. The conveyance rollers 13 a to 13 f convey the workpiece W between the material supply roller 11 and the material removal roller 12. A stage 15 is disposed between the transport roller 13 c and the transport roller 13 d at an intermediate position of the transport device 5. The stage 15 has a number of suction holes (not shown) and is connected to a negative pressure generation source (not shown). The stage 15 sucks the workpiece W through a large number of suction holes and holds the workpiece W flat.

  The droplet discharge head 2 is disposed to face the stage 15. The droplet discharge head 2 is fixed to a carriage 16 having a main scanning axis and a sub-scanning axis orthogonal to the main scanning axis, and draws a predetermined pattern on the surface of the workpiece W.

  As shown in FIG. 2, the droplet discharge head 2 includes a nozzle plate 26, a cavity 23, a vibration plate 22, a piezoelectric element 21 made of PZT or the like, and a common ink chamber 24. A plurality of nozzle holes 25 are formed in the nozzle plate 26. The cavity 23 communicates with the opening of each nozzle hole 25. The diaphragm 22 constitutes one wall surface of the cavity 23. The piezoelectric element 21 displaces the diaphragm 22. The common ink chamber 24 sends the functional liquid into each cavity 23.

  The diaphragm 22 includes a thin plate portion 29 that can be elastically deformed, a convex portion 27, and a thick plate portion that is connected to a head member (not shown). The convex portion 27 and the piezoelectric element 21 are connected to each other.

  With such a configuration, when the piezoelectric element 21 is driven in a contracting direction, the diaphragm 22 bends upward (the direction opposite to the direction in which the nozzle plate 26 is disposed) and the cavity 23 expands, and the common ink chamber 24 functional fluids flow into the cavity 23. Thereafter, when the piezoelectric element 21 is driven in the extending direction, the diaphragm 22 moves in the arrangement direction of the nozzle plate 26 and the cavity 23 contracts. Thereby, the functional liquid in the cavity 23 is compressed, and droplets are ejected from the nozzle hole 25. A predetermined pattern can be formed on the workpiece W depending on which nozzle hole 25 out of the many nozzle holes 25 formed in the droplet discharge head 2 is discharged.

  The droplet discharge device 1 is provided with an inspection unit 3. In the present embodiment, as shown in FIG. 1, the inspection unit 3 is arranged on the upstream side in the conveyance direction of the workpiece W with respect to the droplet discharge head 2.

  As shown in FIG. 2, the inspection unit 3 includes an illumination device 32, an imaging device 31, and a determination unit 33. The illuminating device 32 emits light L1 having a wavelength region equal to or greater than the red wavelength region toward the droplet discharge surface 26a of the nozzle plate 26. More specifically, the illuminating device 32 is composed of a light emitting element that emits light in the red wavelength region having a wavelength of 600 nm or more. For example, a light emitting diode (LED) can be used as the light emitting element. The imaging device 31 receives the reflected light L2 from the droplet discharge surface 26a of the nozzle plate 26 irradiated with light by the illumination device 32, and images the appearance of the droplet discharge surface 26a. The imaging device 31 is constituted by, for example, a CCD camera.

  The determination unit 33 determines the state of the droplet discharge surface 26 a of the nozzle plate 26 based on the imaging result of the imaging device 31. For example, when the determination unit 33 determines that an abnormality has occurred in the droplet discharge surface 26a of the nozzle plate 26, the recovery operation of the droplet discharge head 2 is performed using a flushing unit, a capping unit, a wiping unit, and the like, which will be described later. You may do it. Or you may make it perform the operation | movement which issues a warning with respect to the user of the droplet discharge apparatus 1. FIG.

  In the case of this embodiment, the illumination device 32 and the imaging device 31 are provided on the same axis. The illumination device 32 is disposed on the side far from the nozzle plate 26, and the imaging device 31 is disposed on the side close to the nozzle plate. The arrangement of the illumination device 32 and the imaging device 31 is not limited to this example. For example, the illumination device 32 and the imaging device 31 are not necessarily provided on the same axis.

  A maintenance unit 4 is installed in the droplet discharge device 1. In the present embodiment, as shown in FIG. 1, the maintenance unit 4 is disposed on the upstream side in the transport direction of the workpiece W with respect to the droplet discharge head 2. The maintenance unit 4 includes a flushing unit 44, a capping unit 45, and a wiping unit 46.

  The flushing unit 44 is a device that receives droplets ejected from the droplet ejection head 2 when the flow path in the droplet ejection head 2 is washed. For example, when solid matter is mixed in the droplet discharge head 2 or when the functional liquid is thickened, the solid discharge or the thickened functional liquid is removed from the droplet discharge head 2. The nozzle holes 25 are washed by discharging droplets. The flushing unit 44 has a function of collecting discharged droplets.

  The capping unit 45 is a device that mainly covers the droplet discharge head 2 and sucks the functional liquid in the droplet discharge head 2. The droplets ejected from the droplet ejection head 2 may have volatility. In this case, when the solvent of the functional liquid present in the droplet discharge head 2 volatilizes from the nozzle hole 25, the viscosity of the functional liquid may change and the nozzle hole 25 may be clogged. The capping unit 45 covers the droplet discharge head 2 to prevent the nozzle hole 25 from being clogged. Also, with the liquid droplet ejection head 2 covered, a negative pressure is generated inside the lid, and the functional liquid in the liquid droplet ejection head 2 is sucked, thereby causing bubbles, foreign matter, etc. in the liquid droplet ejection head 2. Can be removed. Thereby, clogging of the nozzle hole 25 can be eliminated, and the droplet discharge head 2 can be recovered.

  The wiping unit 46 is a device that wipes the surface of the nozzle plate 26 of the droplet discharge head 2. The nozzle plate 26 is disposed on the side facing the workpiece W in the droplet discharge head 2. If the functional liquid adheres to the surface of the nozzle plate 26, the functional liquid adhering to the nozzle plate 26 and the workpiece W come into contact with each other, and the functional liquid adheres to an unplanned place in the workpiece W. Sometimes. The wiping unit 46 can prevent adhesion of the functional liquid to an unscheduled place by wiping the nozzle plate 26.

  By moving the carriage 16, the droplet discharge head 2 can be appropriately moved to a position facing the inspection unit 3 or a position facing the maintenance unit 4.

  When the inventor inspects the droplet ejection head 2 using the inspection unit 3 in the droplet ejection apparatus 1 described above and then discharges the functional liquid to produce an organic EL element, the organic EL element having a long lifetime is obtained. The cause of the problem that it was difficult to obtain an element was examined. As a result, it was found that the light emitted from the illumination device deteriorates the functional liquid when imaging the droplet discharge surface of the droplet discharge head.

FIG. 3 shows wavelength ranges of various color lights that can be used as inspection light.
The curve with the symbol SW indicates the spectrum of white light. The spectrum of white light has a sharp peak near the wavelength of 450 nm and a gentle peak near the wavelength of 560 nm.
A curve with a symbol SB indicates a spectrum of blue light. The spectrum of blue light shows a steep peak near the wavelength of 470 nm.
The curve with symbol SG indicates the spectrum of green light. The spectrum of green light shows a steep peak near the wavelength of 520 nm.
The curve with the symbol SR indicates the spectrum of red light. The spectrum of red light shows a steep peak near the wavelength of 640 nm.

  In organic EL devices, when the functional liquid for forming an organic layer used in a light emitting layer, a hole injection layer, a hole transport layer, etc. is irradiated with ultraviolet light or visible light, the functional liquid absorbs the light and deteriorates. There is. Therefore, the present inventor prepared three types of functional liquids in which white light, blue light, and red light were irradiated for 240 hours in a nitrogen atmosphere with respect to the functional liquid used for forming the red light emitting layer. Then, the organic EL element was produced using three types of functional liquids, respectively, and the lifetime of the organic EL element was evaluated. As the lifetime of the organic EL element, LT95 (time until the emission luminance decreases by 5% from the initial value), which is an index used for evaluating the lifetime of the organic EL element, was adopted. The evaluation results are shown in [Table 1].

In [Table 1], those with a lifetime (LT95) of 2000 hours or more are indicated with “◯”, and those with a lifetime of less than 2000 hours are indicated with “x”.
As shown in [Table 1], an organic EL device manufactured with a functional liquid irradiated with white light and an organic EL element manufactured with a functional liquid irradiated with blue light can achieve a lifetime of 2000 hours. There wasn't. This is presumed that the short wavelength component with high energy contained in white light or blue light promotes the oxidation-reduction reaction of the functional liquid, and the functional liquid deteriorates. On the other hand, the organic EL element produced with the functional liquid irradiated with red light was able to achieve a life of 2000 hours or more.

  As described above, the droplet discharge device 1 according to the present embodiment includes the inspection unit 3 that uses light in the wavelength region of the red wavelength region of 600 nm or more as the inspection light, and thus functions in the droplet discharge head 2. Even if the liquid droplet ejection surface 26a is inspected in a state where the liquid is contained, deterioration of the functional liquid due to light irradiation can be suppressed. Therefore, a long-life organic EL element can be manufactured using the droplet discharge device 1 of the present embodiment.

[Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described with reference to FIG.
The basic configuration of the droplet discharge device of this embodiment is the same as that of the first embodiment, and the configuration of the inspection unit is different from that of the first embodiment.
FIG. 4 is a schematic configuration diagram of an inspection unit according to the second embodiment.
In FIG. 4, the same components as those in FIG. 2 used in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  As shown in FIG. 4, in the inspection unit 51 of the second embodiment, the illumination device 52 includes a light emitting element 53 and a filter 54. The light emitting element 53 is a light emitting element that emits light including light in the red wavelength range, specifically, white light, for example. For example, a white LED is used as the light emitting element 53. The filter 54 receives the white light emitted from the light emitting element 53 and transmits the red light component of the white light. More specifically, the filter 54 transmits light having a wavelength range of 600 nm or more and shields light having a wavelength range of less than 600 nm.

  Also in this embodiment, the same effect as that of the first embodiment that a long-life organic EL element can be manufactured is obtained. Furthermore, according to the configuration of the present embodiment, even when the same light emitting element 53 is used, the wavelength range of light irradiated from the inspection unit 51 to the droplet discharge head 2 can be changed by replacing the filter 54. Thereby, the wavelength range of inspection light can be adjusted so that it may become the optimal wavelength range for suppression of deterioration of a functional fluid.

  The filter 54 may be capable of being taken in and out of the optical path of the white light L1 emitted from the light emitting element 53, as indicated by reference numeral 54a in FIG. In this case, the illumination device 52 can switch between irradiation of red light and light in a wavelength region other than the red wavelength region, for example, emission of white light. According to this configuration, for example, when a functional liquid having a color that is easier to observe when irradiated with white light is used, the illumination device can be switched so as to emit white light. Thereby, it can test | inspect using the light according to the kind of functional liquid.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above-described embodiment, the inspection unit includes the imaging device, and the droplet ejection surface of the droplet ejection head is inspected based on the image captured by the imaging device. However, the inspection unit does not necessarily include the imaging device. Good. For example, a method in which the user visually observes the droplet discharge surface may be used. In the above-described embodiment, an example of the droplet discharge device in which the inspection unit is incorporated has been described. However, the inspection unit may be a separate inspection device independent of the droplet discharge device.

In addition, the specific configuration of each part of the droplet discharge device and the inspection unit can be changed as appropriate.
In the above embodiment, light in the red wavelength range is used as the light emitted toward the droplet discharge surface 26a. However, light in the infrared wavelength range having a longer wavelength than the red wavelength range may be used. In that case, an infrared camera having high sensitivity to infrared light may be used as the imaging device.
The present invention may also be applied to a droplet discharge apparatus for manufacturing electronic devices other than organic EL elements.

  DESCRIPTION OF SYMBOLS 1 ... Droplet discharge device, 2 ... Droplet discharge head, 3,51 ... Inspection unit (droplet discharge head inspection device), 26a ... Droplet discharge surface, 31 ... Imaging device, 32 ... Illumination device, 53 ... Light emitting element 54 ... Filter.

Claims (8)

An illumination device that emits light in a wavelength region greater than or equal to the red wavelength region toward a droplet ejection surface of a droplet ejection head that ejects a functional liquid;
An imaging device that images the droplet ejection surface irradiated with light from the illumination device;
A droplet discharge head inspection apparatus comprising:   The droplet discharge head inspection apparatus according to claim 1, wherein a wavelength range included in light emitted from the illumination device is 600 nm or more. An illumination device that emits light including a wavelength region of at least a red wavelength region toward a droplet ejection surface of a droplet ejection head that ejects a functional liquid;
An imaging device that images the droplet ejection surface irradiated with light from the illumination device;
A droplet discharge head inspection apparatus comprising: a filter that is disposed between the illumination device and the imaging device and shields light in a wavelength range shorter than the red wavelength range.   4. The liquid droplet ejection head inspection apparatus according to claim 3, wherein the filter that transmits light in the red wavelength region transmits light having a wavelength region of 600 nm or more and shields light having a wavelength region of less than 600 nm. .   5. The lighting device according to claim 1, wherein the illumination device can switch between emission of light in the red wavelength range and emission of light in a wavelength range other than the red wavelength range. The droplet discharge head inspection device according to claim 1.   6. The liquid droplet ejection head inspection apparatus according to claim 1, wherein the functional liquid is a functional liquid used for forming an organic layer of an organic electroluminescence element. The droplet discharge head;
A liquid droplet ejection apparatus comprising: the liquid droplet ejection head inspection apparatus according to any one of claims 1 to 6. Irradiate light in the wavelength range above the red wavelength range toward the droplet ejection surface of the droplet ejection head that ejects the functional liquid.
A method for inspecting a droplet discharge head, wherein the droplet discharge surface irradiated with the light is observed.

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